In this work, the designs of both non-iterative and iterative approximate logarithmic multipliers (LMs) are studied to further reduce power consumption and improve performance. Non-iterative approximate LMs (ALMs) that use three inexact mantissa adders, are presented. The proposed iterative approximate logarithmic multipliers (IALMs) use a set-one adder in both mantissa adders during an iteration; they also use lower-part-or adders and approximate mirror adders for the final addition. Error analysis and simulation results are also provided; it is found that the proposed approximate LMs with an appropriate number of inexact bits achieve a higher accuracy and lower power consumption than conventional LMs using exact units. Compared with conventional LMs with exact units, the normalized mean error distance (NMED) of 16-bit approximate LMs is decreased by up to 18% and the power-delay product (PDP) has a reduction of up to 37%. The proposed approximate LMs are also compared with previous approximate multipliers; it is found that the proposed approximate LMs are best suitable for applications allowing larger errors, but requiring lower energy consumption and low power. Approximate Booth multipliers fit applications with less stringent power requirements, but also requiring smaller errors. Case studies for error-tolerant computing applications are provided.

The collaboration between humans and robots is one of the most disruptive and challenging research areas. Even considering advances in design and artificial intelligence, humans and robots could soon ally to perform together a number of different tasks. Robots could also became new playmates. In fact, an emerging trend is associated with the so-called phygital gaming, which builds upon the idea of merging the physical world with a virtual one in order to let physical and virtual entities, such as players, robots, animated characters and other game objects interact seamlessly as if they were all part of the same reality. This paper specifically focuses on mixed reality gaming environments that can be created by using floor projection, and tackles the issue of enabling accurate and robust tracking of off-the-shelf robots endowed with limited sensing capabilities. The proposed solution is implemented by fusing visual tracking data gathered via a fixed camera in a smart environment with odometry data obtained from robot's on-board sensors. The solution has been tested within a phygital gaming platform in a real usage scenario, by experimenting with a robotic game that exhibits many challenging situations which would be hard to manage using conventional tracking techniques.

Software for computer animation is generally characterized by a steep learning curve, due to the entanglement of both sophisticated techniques and interaction methods required to control 3D geometries. This paper proposes a tool designed to support computer animation production processes by leveraging the affordances offered by articulated tangible user interfaces and motion capture retargeting solutions. To this aim, orientations of an instrumented prop are recorded together with animator's motion in the 3D space and used to quickly pose characters in the virtual environment. High-level functionalities of the animation software are made accessible via a speech interface, thus letting the user control the animation pipeline via voice commands while focusing on his or her hands and body motion. The proposed solution exploits both off-the-shelf hardware components (like the Lego Mindstorms EV3 bricks and the Microsoft Kinect, used for building the tangible device and tracking animator's skeleton) and free open-source software (like the Blender animation tool), thus representing an interesting solution also for beginners approaching the world of digital animation for the first time. Experimental results in different usage scenarios show the benefits offered by the designed interaction strategy with respect to a mouse \& keyboard-based interface both for expert and non-expert users.

Blockchain technology is receiving an ever-increasing attention. In this work, we present pros and cons of this technology, by taking the point of view of (IT) professionals evaluating whether to embrace this technology or not for their business. Use cases selected from a particular domain represented by the insurance sector are analyzed, and several application guidelines that can be generalized and applied to other sectors are identified

The last couple of years witnessed the explosion of two major technological revolutions, with vehicles, that started to be regarded as the next frontier for artificial intelligence and blockchain, which began to be considered by the wider public for the great changes it could bring in a number of heterogeneous domains. In order to take part in these revolutions, in this paper we show how blockchain and sensors installed on a vehicle could be combined to (semi-)automatically activate/deactivate car insurance covers in an envisaged on-demand insurance scenario. We present a prototype, which includes a mobile app and a portable electronic device to be installed onboard. The mobile app lets the driver dynamically change the status of specific insurance covers (in some cases, after pictures of the vehicle have been taken to attest its conditions). Each modification (and picture hash) is saved on the blockchain within a smart contract, in order to certify changes made (and vehicle's status). Sensors embedded in the electronic device are used to collect passengers' and vehicle's data. Data are then used to automatically modify insurance covers based on car/environment conditions and preferences set. The proposed solution could help lowering policy modification costs and limiting insurance frauds.

This is the beginning of the year EiC update on the IEEE Transactions on Computers

This installment of Computer's series highlighting the work published in IEEE Computer Society journals comes from IEEE Transactions on Computers.

In this paper we describe an optimization for binary radix-16 (modified) Booth recoded multipliers to reduce the maximum height of the partial product columns to ceil(n/4) for n = 64-bit unsigned operands. This is in contrast to the conventional maximum height of ceil((n + 1)/4). Therefore a reduction of one unit in the maximum height is achieved. This reduction may add flexibility during the design of the pipelined multiplier to meet the design goals, it may allow further optimizations of the partial product array reduction stage in terms of area/delay/power and/or may allow additional addends to be included in the partial product array without increasing the delay. The method can be extended to Booth recoded radix-8 multipliers, signed multi- pliers, combined signed/unsigned multipliers, and other values of n.

Computer-supported assessment tools can bring significant benefits to both students and teachers. When integrated in traditional education workflows, they may help to reduce the time required to perform the evaluation and consolidate the perception of fairness of the overall process. When integrated within on-line intelligent tutoring systems, they could provide students with a timely feedback and support self-assessment activities. The current work presents an alternative approach (and not just a \"yet-another-implementation\") to the problem of automatically evaluating technical skills needed to create 3D computer animations. Although some solutions have been reported already in the literature, their applicability is partially constrained, as they require the teaching staff to define evaluation criteria that are strictly linked to the particular animation technique being assessed. Students are forced to operate in environments where they can only perform a part of the required animation steps, by using a pre-defined set of techniques and tools. To address such limitations, the proposed system exploits shape- and time-based features extracted from the 3D point clouds (i.e., the set of data points) describing animated geometries, which are independent of the particular animation techniques used. Experimental observations collected in the evaluation of course assignments in which students were asked to recreate 3D animations of deformable meshes prepared by the teaching staff showed a good correlation between automatic and manual evaluations. Obtained results confirmed the ability of the proposed approach to cope with heterogeneous evaluation tasks in which the relevant learning outcomes can be properly considered.

This is the state of the journal editorial for 2017, summarizing the results obtained in 2016 and presenting the new initiatives for 2017

The purpose of this study was to compare different students' backgrounds and two different didactic methodologies to profitably teach computer animation in Italian schools of design and engineering. Teachers and instructors have long been engaged in discussions to define effective curricula for teaching computer animation. Various multidisciplinary and collaborative methodologies have been proposed. This manuscript assesses both the impact of a collaborative teaching approach and the curriculum. Two equivalent learning paths are compared; both of them encompass courses of photography, storytelling and computer animation and require prerequisites in 3D modeling and rendering. The learning path of the \"Systemic Design\" degree is taught by the collaborative Open Space Technology (OST) approach, whereas the path of \"Cinema and Media Engineering\" is taught more conventionally (independent courses). The results clearly show how effective teaching methodologies cannot completely compensate for a nontechnical background; on the other hand, as expected, students appreciate and can take advantage of collaborative forms of teaching.

This paper presents a framework for automatically generating speech-based interfaces for controlling virtual and augmented reality (AR) applications on wearable devices. Starting from a set of natural language descriptions of application functionalities and a catalog of general-purpose icons, annotated with possible implied meanings, the framework creates both vocabulary and grammar for the speech recognizer, as well as a graphic interface for the target application, where icons are expected to be capable of evoking available commands. To minimize user's cognitive load during interaction, a semantics-based optimization mechanism was used to find the best mapping between icons and functionalities and to expand the set of valid commands. The framework was evaluated by using it with see-through glasses for AR-based maintenance and repair operations. A set of experimental tests were designed to objectively and subjectively assess first-time user experience of the automatically generated interface in relation to that of a fully personalized interface. Moreover, intuitiveness of the automatically generated interface was studied by analyzing the results obtained through trained users on the same interface. Objective measurements (in terms of false positives, false negatives, task completion rate, and average number of attempts for activating functionalities) and subjective measurements (about system response accuracy, likeability, cognitive demand, annoyance, habitability, and speed) reveal that the results obtained by the first-time users and experienced users with the proposed framework's interface are very similar, and their performances are comparable with those of both the considered references.

The purpose of this study was to compare different students' backgrounds and two different didactic methodologies to profitably teach computer animation in Italian schools of design and engineering. Teachers and instructors have long been engaged in discussions to define effective curricula for teaching computer animation. Various multidisciplinary and collaborative methodologies have been proposed. This manuscript assesses both the impact of a collaborative teaching approach and the curriculum. Two equivalent learning paths are compared; both of them encompass courses of photography, storytelling and computer animation and require prerequisites in 3D modeling and rendering. The learning path of the \"Systemic Design\" degree is taught by the collaborative Open Space Technology (OST) approach, whereas the path of \"Cinema and Media Engineering\" is taught more conventionally (independent courses). The results clearly show how effective teaching methodologies cannot completely compensate for a nontechnical background; on the other hand, as expected, students appreciate and can take advantage of collaborative forms of teaching.

The players of the digital industry look at network Big Data as an incredible source of revenues, which can allow them to design products, services and market strategies ever more tailored to users' interests and needs. This is the case of data collected by Web analytics tools, which describe the way users interact with Web contents and where their attention focuses onto during navigation. Given the complexity of information to analyze, existing tools often make use of visualization strategies to represent data aggregated throughout separate sessions and multiple users. In particular, heat maps are often adopted to study the distribution of mouse activity and identify page regions that are more frequently reached during interaction. Unfortunately, since Web contents are accessed via ever more heterogeneous devices, region-based heat maps cannot be exploited anymore to aggregate data concerning user's attention, since the same Web content may move to another page location or exhibit a different aspect depending on the access device used or the user agent setup. This paper presents the design of a visual analytics framework capable to deal with the above limitation by adopting a data collection approach that combines information about regions displayed with information about page structure. This way, the well-known heat map-based visualization can be produced, where interactions can be aggregated on a per-element basis independently of the specific access configuration. Experimental results showed that the framework succeeds in accurately quantifying user's attention and replicating results obtained by manual processing.

Agri-food companies, operating in the packaging, storage and distribution of fruit and vegetables, need to be provided with information systems able to meet the requirements imposed by the current European regulations in terms of traceability. This paper evaluates the benefits and drawbacks of a semi-automated information management tracking system for a warehouse specialized in the fruit market. It is targeted to small and medium-sized companies, with limited financial means for investments and without technical support in their premises. These requirements are met by using a PDA equipped with an RFID reader: the information collected throughout the production process are locally stored in the PDA and occasionally sent to a server. In this way the proposed system does not rely neither on a widespread wireless network, nor on fixed RFID readers, which can increase automation, but need more investment and assistance.

Recent graphic processing units (GPUs) have remarkable raw computing power, which can be used for very computationally challenging problems. Like in micromagnetic simulations, where the magnetostatic field computation to analyze the magnetic behavior at very small time and space scale demands a huge computation time. This paper presents a multidimensional FFT-based parallel implementation of a magnetostatic field computation on GPUs. We have developed a specialized 3D FFT library for magnetostatic field calculation on GPUs. This made it possible to fully exploit the symmetries inherent in the field calculation and other optimizations specific to the GPUs architecture. We have compared our results with the widely used CPU-based parallel OOMMF program and with an equivalent serial implementation on CPU. The results have shown a speedup of up to 95x and 8.7x for single and 66x and 4.6x for double precision floating point accuracy against equivalent serial implementation and OOMMF, respectively.

Nowadays, traceability represents a key activity in many sectors. Many modern traceability systems are based on radio-frequency identification (RFID) technology. However, the distributed information stored on RFID tags involves new security problems. This paper presents the traceability multi-entity cryptography, a high-level data protection scheme based on public key cryptography that is able to protect RFID data for traceability and chain activities. This scheme is able to manage entities with different permissions, and it is especially suitable for applications that require complex Information Systems. Traceability multi-entity cryptography avoids industrial espionage, guarantees the information authenticity, protects the customer privacy, and detects malicious alterations of the information. In contrast to the state-of-the-art RFID security schemes, the proposed protocol is applicable to standard RFID tags without any cryptographic capability, and it does not require a central database.

Purpose To compare the acceptability of computed tomographic (CT) colonography and flexible sigmoidoscopy (FS) screening and the factors predicting CT colonographic screening participation, targeting participants in a randomized screening trial. Materials and Methods Eligible individuals aged 58 years (n = 1984) living in Turin, Italy, were randomly assigned to be invited to screening for colorectal cancer with FS or CT colonography. After individuals who had died or moved away (n = 28) were excluded, 264 of 976 (27.0%) underwent screening with FS and 298 of 980 (30.4%) underwent CT colonography. All attendees and a sample of CT colonography nonattendees (n = 299) were contacted for a telephone interview 3-6 months after invitation for screening, and screening experience and factors affecting participation were investigated. Odds ratios (ORs) were computed by means of multivariable logistic regression. Results For the telephone interviews, 239 of 264 (90.6%) FS attendees, 237 of 298 (79.5%) CT colonography attendees, and 182 of 299 (60.9%) CT colonography nonattendees responded. The percentage of attendees who would recommend the test to friends or relatives was 99.1% among FS and 93.3% among CT colonography attendees. Discomfort associated with bowel preparation was higher among CT colonography than FS attendees (OR, 2.77; 95% confidence interval [CI]: 1.47, 5.24). CT colonography nonattendees were less likely to be men (OR, 0.36; 95% CI: 0.18, 0.71), retired (OR, 0.31; 95% CI: 0.13, 0.75), to report regular physical activity (OR, 0.37; 95% CI: 0.20, 0.70), or to have read the information leaflet (OR, 0.18; 95% CI: 0.08, 0.41). They were more likely to mention screening-related anxiety (mild: OR, 6.30; 95% CI: 2.48, 15.97; moderate or severe: OR, 3.63; 95% CI: 1.87, 7.04), erroneous beliefs about screening (OR, 32.15; 95% CI: 6.26, 165.19), or having undergone a recent fecal occult blood test (OR, 13.69; 95% CI: 3.66, 51.29). Conclusion CT colonography and FS screening are well accepted, but further reducing the discomfort from bowel preparation may increase CT colonography screening acceptability. Negative attitudes, erroneous beliefs about screening, and organizational barriers are limiting screening uptake; all these factors are modifiable and therefore potentially susceptible to interventions. (©) RSNA, 2017 Online supplemental material is available for this article.

A spotlight on the IEEE Transactions on Computers, on Computer Arithmetic and its impact.

A recent trend in human-computer interaction is to ease the creation of content such as apps and games via intelligent systems, allowing nonskilled users to define a given system's behavior through visual programming or simplified metalanguages. However, when the number of elements to be controlled increases, the complexity could become comparable to that of traditional coding strategies. This article addresses this issue by proposing a framework for automatically configuring a system's behavior based on user input and context information. Framework effectiveness has been tested in a game-creation scenario and used for automatically mapping user commands on virtual character actions based on a natural language description of the game scene. The use of semantics-based mapping reduces the effort and complexity linked with the configuration of the interaction logic, thus decreasing the number of commands needed for controlling the characters. The Web extra includes the questionnaire and full catalogue of descriptions collected

In this paper the Editor-in-Chief of the IEEE Transactions on Computers, both presents the state of the journal after (almost) the completion of the first year since the beginning of his term, and introduces the new Associate Editors

This is the July report on the state of the IEEE Transactions on Computers

Sensors are becoming ubiquitous in all areas of science, technology, and society. In this Special Issue on \"Sensors for Entertainment\", developments in progress and the current state of application scenarios for sensors in the field of entertainment is explored

The term Augmented Reality (AR) refers to a set of technologies and devices able to enhance and improve human perception, thus bridging the gap between real and virtual space. Physical and artificial objects are mixed together in a hybrid space where the user can move without constraints. This mediated reality is spread in our everyday life: work, study, training, relaxation, time spent traveling are just some of the moments in which you can use AR applications. This paper aims to provide an overview of current technologies and future trends of augmented reality as well as to describe the main application domains, outlining benefits and open issues

Symmetric encryption is the most widely adopted security solution for wireless sensor networks. The main open issue in this context is represented by the establishment of symmetric keys. Although many key management schemes have been proposed in order to guarantee a high security level, a solution without weaknesses does not yet exist. An important class of key management schemes is based on a transitory master key (MK). In this approach, a global secret is used during the initialization phase to generate pair-wise keys, and it is deleted during the working phase. However, if an adversary compromises a node before the deletion of the MK, the security of the whole network is compromised. In this paper, a new key negotiation routine is proposed. The new routine is integrated with a well-known key computation mechanism based on a transitory master secret. The goal of the proposed approach is to reduce the time required for the initialization phase, thus reducing the probability that the master secret is compromised. This goal is achieved by splitting the initialization phase in hierarchical subphases with an increasing level of security. An experimental analysis demonstrates that the proposed scheme provides a significant reduction in the time required before deleting the transitory secret material, thus increasing the overall security level. Moreover, the proposed scheme allows to add new nodes after the first deployment with a suited routine able to complete the key establishment in the same time as for the initial deployment.

Transient faults in safety-critical computer-based systems represent a major issue for guaranteeing correct system behaviour. Fault injection is a commonly used method to evaluate the sensitivity of such systems. This paper presents a fault injection tool, called KITO, to evaluate the effects of faults in memory containing data structures belonging to a Unix-based Operating System and, in particular, elements linked to resource synchronization management. An experimental analysis was conducted on a large set of memory elements of the Operating System itself, while the system was subject to stress from benchmark programs that use different elements of the Linux kernel. Experimental results show that synchronization aspects of the kernel are susceptible to a significant set of possible errors ranging from performance degradation to failure in successfully completing the benchmark application.

Toner savings in monochromatic printing are an important target for improving green computing performance and more specifically green printing. In order to extend the lifetime of the printer cartridge some options are available for laser printers, usually reducing the number of dots with respect to the normal print quality. However available algorithms and patents do not provide a method for dynamically adapting the percentage of toner savings to the required printing quality. In this paper, we introduce a new quasi-random sequence based algorithm for reducing the number of dots in the printing process, able to achieve optimal discrepancy and low computational complexity, for all print quality levels. In order to reduce patterns in the removed dots, blue noise dithering is applied when the desired percentage of toner savings is moderate. The proposed solution can be easily implemented in the printer firmware, given its low computational complexity. In order to verify the results from a perceptual point of view, an extended test with 135 volunteers and more than 5000 comparisons has been performed, besides checking that toner is effectively saved. Results show that the proposed approach can produce a reduction of the perceived quality almost directly proportional to the number of monochromatic dots skipped, with only a reduced influence from the font used. The perceptual results are better in the proposal than in previous approaches. The proposed algorithm appears to be a promising technique for improving green printing in monochromatic laser printers without using custom fonts

Northern Italy has one of the highest air pollution levels in the European Union. This paper describes a mobile wireless sensor network system intended to complement the already existing official air-quality monitoring systems of the metropolitan town of Torino. The system is characterized by a high portability and low cost, in both acquisition and maintenance. The high portability of the system aims to improve the spatial distribution and resolution of the measurements from the official static monitoring stations. Commercial PM10 and O3 sensors were incorporated into the system, and were subsequently tested in a controlled environment and on the field. Test on the field, performed in collaboration with the local environmental agency, revealed that the sensors can provide accurate data if properly calibrated and maintained. Further tests were carried out by mounting the system on bicycles in order to increase their mobility.

Rationale: Omalizumab, an anti-IgE monoclonal antibody, is indicated in adults with severe persistent allergic asthma. Exhaled molecular markers can provide phenotypic information in asthma. Objectives: Determine whether adults with severe asthma on omalizumab (anti-IgE+) have a different breathprint compared with those who were not on anti-IgE therapy (anti-IgE-) as assessed by eNoses and gas chromatography/mass spectrometry (GC/MS) (breathomics). Methods: This was a cross-sectional analysis of the U- BIOPRED adult cohort. Severe asthma was defined by IMI-criteria [Bel, Thorax 2011]. Anti-IgE+ patients were on a regular treatment with s.c. omalizumab (150-375 mg) every 2-4 weeks. Exhaled volatile compounds trapped on adsorption tubes were analysed by a centralized eNose platform (Owlstone Lonestar, two Cyranose 320, Comon Invent, Tor Vergata TEN), including a total of 190 sensors, and GC/MS. Recursive feature elimination (http://topepo.github.io/caret/rfe.html) was used for feature selection and random forests, more robust to overfitting, for classification. Results: 9 anti- IgE+ (females/males 2/7, age 52.6±16.3 years, mean±SD, 1/2/6 current/ex/nonsmokers, pre-bronchodilator FEV1 70.6±21.1% predicted value) and 30 anti-IgE- patients (18/12 females/males, age 53.2±14.2 years, 0/16/14 current/ex/nonsmokers, pre-bronchodilator FEV1 59.6±30.7% predicted value) were studied. Conclusions: Preliminary results suggest that breathomics can distinguish between anti-IgE+ and anti-IgE- severe asthma patients.

Inexact (or approximate) computing is an attractive paradigm for digital processing at nanometric scales. Inexact computing is particularly interesting for computer arithmetic designs. This paper deals with the analysis and design of two new approximate 4-2 compressors for utilization in a multiplier. These designs rely on different features of compression, such that imprecision in computation (as measured by the error rate and the so-called normalized error distance) can be met with respect to circuit-based figures of merit of a design (number of transistors, delay and power consumption). Four different schemes for utilizing the proposed approximate compressors are proposed and analyzed for a Wallace multiplier. Extensive simulation results are provided and an application of the approximate multipliers to image processing is presented. The results show that the proposed designs accomplish significant reductions in power dissipation, delay and transistor count compared to an exact design; moreover, two of the proposed multiplier designs provide excellent capabilities for image multiplication with respect to average normalized error distance and peak signal-to-noise ratio (more than 50 dB for the considered image examples)

This is the welcome message from the incoming Editor-in-Chief (EiC) of the IEEE Transactions on Computers. For the first time in 64 years of life of the IEEE Transactions on Computers, a Researcher from Continental Europe has been appointed to serve as EiC

Robustly and efficiently tracking pedestrians in the infrared spectrum is a crucial requirement for a number of applications. At the same time, it is also particularly critical due to both the peculiarities of infrared images and pedestrian targets. In fact, low resolutions and high signal-to-noise ratios combined with extremely variable target signatures, chaotic trajectories, and frequent occlusions have forced researchers to develop ever more complex strategies characterized by a neat trade-off between tracking accuracy and computational complexity. Thus, most of the existing techniques might not be capable of ensuring real-time performances with a suitable degree of robustness, especially on limited-resource hardware used, e.g., in automotive or security scenarios. We present a technique that extends an extremely efficient tracking method originally tailored to targets that exhibit a clear and stable hot spot to allow it to deal with pedestrian targets by reusing its core components and integrating an occlusion detection and recovery mechanism. Experimental results obtained on public datasets confirmed that the devised method is able to obtain a robustness that is superior to that of other common approaches by maintaining the high tracking speed of the reference method

This installment of Computer's series highlighting the work published in IEEE Computer Society journals comes from the IEEE Transactions on Computers

In this paper the Editor-in-Chief of the IEEE Transactions on Computers, presents the state of the journal after 5 months since the beginning of his term, as well as introduces the new Associate Editors

Memories are one of the most critical components of many systems: due to exposure to energetic particles, fabrication defects and aging they are subject to various kinds of permanent and transient errors. In this scenario, Unequal Error Protection (UEP) techniques have been proposed in the past to encode stored information, allowing to detect and possibly recover from errors during load operations, while offering different levels of protection to partitions of codewords according to their importance. Low-Density Parity-Check (LDPC) codes are used in many communication standards to encode the transmitted information: at reception, LDPC decoders heavily rely on memories to store and correct the received information. To ensure efficient and reliable decoding of information, the need to protect the memories used in LDPC decoders is of primary importance. In this paper we present a study on how to efficiently design UEP techniques for LDPC decoder memories. The devised UEP method is divided in four adjustable levels, each one offering a different degree of protection. The full UEP, along with simplified versions, has been implemented within an existing decoder and its area occupation and power consumption evaluated. Comparison with the literature on the subject shows an unmatched level of protection from errors at a small complexity and energy cost

Motion capture systems provide an efficient and interactive solution for extracting information related to a human skeleton, which is often exploited to animate virtual characters. When the character cannot be assimilated to an anthropometric shape, the task to map motion capture data onto the armature to be animated could be extremely challenging. This paper presents two methodologies for the automatic mapping of a human skeleton onto virtual character armatures. Kinematics chains of the human skeleton are analyzed in order to map joints, bones and end-effectors onto an arbitrary shaped armatures. Both forward and inverse kinematics are considered. A prototype implementation has been developed by using the Microsoft Kinect as body tracking device. Results show that the proposed solution can already be used to animate truly different characters ranging from a Pixar-like lamp to different kinds of animals

The ever more complex labor world and the current economic crisis ask learners and workers to continuously update their qualification level to stay relevant on the market. Hence, education and training providers need to adjust their offer in order to cope with such evolving requirements. However, because of the huge number of variables to consider, finding the right learning content able to let an individual fill his/her competency gap may be a task hard to accomplish. In this paper we propose a semantic-based recommender system that is designed to cross heterogeneous information about learners' and workers' background as well as advertised job positions with a catalogue of online courses in order to identify the most appropriate learning resources. Experimental observations showed a good agreement between human and automatic recommendations, confirming the applicability of the emerging semantic technology to the generation of user-centered services capable to adapt to individual's learning needs

Advancements in input device and sensor technologies led to the evolution of the traditional human-machine interaction paradigm based on the mouse and keyboard. Touch-, gesture- and voice-based interfaces are integrated today in a variety of applications running on consumer devices (e.g., gaming consoles and smartphones). However, to allow existing applications running on desktop computers to utilize natural interaction, significant re-design and re-coding efforts may be required. In this paper, a framework designed to transparently add multi-modal interaction capabilities to applications to which users are accustomed is presented. Experimental observations confirmed the effectiveness of the proposed framework and led to a classification of those applications that could benefit more from the availability of natural interaction modalities

Public authorities have been designing and developing several initiatives for more than ten years in the attempt to guarantee an easy access and a wide offer of on-line services to citizens. Moreover, public authorities should guarantee a common heritage of data, accessible for any person at the same conditions. Despite of these initiatives, public bodies are still often dependent on software vendors. The European project OASIS aims to place the user at the center of a sustainable ecosystem where data, described by an open format, are shared among interoperable and reusable services. This approach allows public authorities to reduce costs, citizens to benefit of a wide range of high quality services and service providers to access to linked data for the development of new applications. Providers can also be part of the OASIS ecosystem, thus benefiting of an open a sustainable economic model. This manuscript describes in the details motivations behind the OASIS project and the portal Ozwillo, presents the platform architecture and discusses preliminary results.

The aim of this work was to evaluate differences in energy flows between normal and immortalized cells when these distinct biological systems are exposed to environmental stimulation. These differences were considered using a constructal thermodynamic approach, and were subsequently verified experimentally. The application of constructal law to cell analysis led to the conclusion that temperature differences between cells with distinct behaviour can be amplified by interaction between cells and external fields. Experimental validation of the principle was carried out on two cellular models exposed to electromagnetic fields. By infrared thermography we were able to assess small changes in heat dissipation measured as a variation in cell internal energy. The experimental data thus obtained are in agreement with the theoretical calculation, because they show a different thermal dispersion pattern when normal and immortalized cells are exposed to electromagnetic fields. By using two methods that support and validate each other, we have demonstrated that the cell/environment interaction can be exploited to enhance cell behavior differences, in particular heat dissipation. We propose infrared thermography as a technique effective in discriminating distinct patterns of thermal dispersion and therefore able to distinguish a normal phenotype from a transformed one

Thresholds of vision under low-light conditions have been studied for determining the human response to light stimuli in different contexts. Blackwell's work on thresholds of vision of the human visual system did not explore some variables whose analysis would help to characterize more deeply the visual system. This paper extends Blackwell's results exploring new dimensions of the human visual system response including chromaticity of the stimuli, mono/binocular vision, and dark adaptation. Tests have been performed on a sample of 45 observers, with a simplified laboratory setup with respect to Blackwell and without specific hardware/software, producing results in terms of visual adaptation, monocular, and binocular vision and aging effects

To compare breast density (BD) assessment provided by an automated BD evaluator (ABDE) with that provided by a panel of experienced breast radiologists, on a multivendor dataset. Methods Twenty-one radiologists assessed 613 screening/ diagnostic digital mammograms from nine centers and six different vendors, using the BI-RADS a, b, c, and d density classification. The same mammograms were also evaluated by an ABDE providing the ratio between fibroglandular and total breast area on a continuous scale and, automatically, the BI-RADS score. A panel majority report (PMR) was used as reference standard. Agreement (κ) and accuracy (proportion of cases correctly classified) were calculated for binary (BI-RADS a-b versus c-d) and 4-class classification. Results While the agreement of individual radiologists with the PMR ranged from κ=0.483 to κ=0.885, the ABDE correctly classified 563/613 mammograms (92 %). A substantial agreement for binary classification was found for individual reader pairs (κ=0.620, standard deviation [SD]=0.140), individual versus PMR (κ=0.736, SD=0.117), and individual versus ABDE (κ=0.674, SD=0.095). Agreement between ABDE and PMR was almost perfect (κ=0.831). Conclusions The ABDE showed an almost perfect agreement with a 21-radiologist panel in binary BD classification on a multivendor dataset, earning a chance as a reproducible alternative to visual evaluation.

As technological, economic, and social factors drive scientific publishing toward electronic formats, opportunities open beyond traditional reading and writing frameworks. Journal articles now, and in the future, can increasingly include a variety of supplemental multimedia and interactive materials for augmented reading that will impact both the nature and presentation of scientific research. The IEEE Computer Society is preparing for this evolution

Augmented reality (AR) is a well-known technology that can be exploited to provide mass-market users an effective and customizable support in a large spectrum of personal applications, by overlapping computer-generated hints to the real world. Mobile devices, such as smartphones and tablets, are playing a key role in the exponential growth of this kind of solutions. Nonetheless, there exists some application domains that just started to take advantage from the AR systems. Maintenance, repair, and assembly have been considered as strategic fields for the application of the AR technology from the 1990s, but often only specialists using ad hoc hardware were involved in limited experimental tests. Nowadays, AR-based maintenance and repair procedures are available also for end-users on consumer electronics devices. This paper aims to explore new challenges and opportunities of this technology, by also presenting the software framework that is being developed in the EASE-R3 project by exploiting reconfigurable AR procedures and tele-assistance to overcome some of the limitations of current solutions

Rationale: Some severe asthma patients require oral corticosteroids (OCS) likely due to greater disease severity. Exhaled molecular markers can provide phenotypic information in asthma. Objectives: Determine whether patients on OCS (OCS+) have a different breathprint compared with those who were not on OCS (OCS-); determine the classification accuracy of eNose as compared to FEV1 % pred, % sputum eosinophils, and exhaled nitric oxide (FENO). Methods: This was a cross-sectional analysis of the U-BIOPRED cohort. Severe asthma was defined by IMI-criteria [Bel Thorax 2011]. OCS+ patients had daily OCS. OCS- patients had never had OCS and were on maintenance inhaled fluticasone equivalent >1000 μg/day. Exhaled volatile organic compounds trapped on adsorption tubes were analysed by centralized eNose platform (Owlstone Lonestar, Cyranose 320, Comon Invent, Tor Vergata TEN) including a total of 190 sensors. t test was used for comparing groups and support vector machine with leave-one-out cross-validation as a classifier. Results: 33 OCS+ (age 55±11yr, mean±SD, 52% female, 27% smokers, pre-bronchodilator FEV1 64.1±24% pred) and 40 OCS- severe asthma patients (age 54±15yr, mean±SD, 55% female, 35% smokers, pre-bronchodilator FEV1 61.8±24% pred) were studied. Sensor by sensor analysis showed that 56 sensors provided different mean values (change in sensor resistance or frequency) between groups (P<0.05). Accuracy of classification was as follows: eNose 71% (n=73), FENO 71% (n=70), FEV1 62% (n=73) and sputum eosinophils 59% (n=37). Conclusions: Preliminary results suggest OCS+ and OCS- severe asthma patients can be distinguished by an eNose platform

Recently, indoor navigation on mobile devices has received attention from both startups and large vendors, since it has many relevant practical and commercial applications. User positioning and navigation using GPS signals is becoming more and more popular, mainly due to the increasing availability of acceptable quality sensors into low-cost consumer devices as smartphones. However, indoor GPS-navigation is highly unreliable because of the poor communication with satellites and the lack of detailed maps. In this paper we discuss the technologies allowing the indoor computation of accurate location and orientation data, as well as other issues and challenges that indoor navigation apps should cope with. In particular, we present and make explicit reference to a system for indoor navigation (running on a smartphone), which has been designed by the Authors, including the main problems that have been tackled during its implementation

This survey of current job search and recruitment tools focuses on applying a computer-based approach to job matchmaking. The authors present a semantic-based software platform, LO-MATCH - developed in the framework of a European project on lifelong learning - that highlights future research directions. There are three related Web extras that provide supplemental material

Here we give context to the Special Issue on \"Detection and Tracking of Targets in Forward-Looking InfraRed (FLIR) Imagery\" in Sensors. We start with an introduction to the role of infrared images in today's vision-based applications, by outlining the specific challenges that characterize detection and tracking in FLIR images. We then illustrate why selected papers have been chosen to represent the domain of interest, by summarizing their main contributions to the state-of-the-art. Lastly, we sum up the main evidence found, and we underline some of the aspects that are worthy of further investigation in future research activities

Assessment is a delicate task in the overall teaching process because it may require significant time and may be prone to subjectivity. Subjectivity is especially true for disciplines in which perceptual factors play a key role in the evaluation. In previous decades, computer-based assessment techniques were developed to address the above-mentioned challenges and to automatically grade students' work in a variety of educational fields. In this paper, the application of automatic assessment strategies in the unexplored domain of computer graphics is discussed. In particular, a tool that is designed to evaluate student assignments for a 3D computer animation course taught at Politecnico di Torino University is presented. During laboratory examination sessions, students are requested to individually operate on the open-source Blender suite and to recreate a 3D animation similar to a reference one. Student's output is assessed against a set of similarity indicators, which are specifically designed to capture the technical and perceptual factors that would be blended in a traditional teacher's evaluation. A comparison of the results that are achieved by the computer-based tool with grades assigned by visual inspection confirms the effectiveness of the designed approach and displays a high-quality concurrence between automatic and manual evaluations

The automatic extraction of objective features from paintings, like brushstrokes distribution, orientation and shape, could be particularly useful for different artwork analysis and management tasks. In fact, these features contribute to provide a unique signature of the artists' style and can be effectively used for artist identification and classification, artwork examination and retrieval, etc. In this paper, an automatic technique for unsupervised extraction of individual brushstrokes from digital reproductions of van Gogh's paintings is presented. Through the iterative application of segmentation, characterization and validation steps, valid brushstrokes complying with specific area and shape constraints are identified. On the extracted brushstrokes, several representative features can then be calculated, like orientation, length and width. The accuracy of the devised method is evaluated by comparing numerical results obtained on a dataset of digital reproductions of van Gogh's oil-on-canvas works with observations made by human subjects and with another recent approach for automatic brushstrokes analysis. Experimental tests showed that the devised methodology produces results that are rather close to those obtained by human subjects and, for some of the metrics considered, can provide improved performances with respect to alternative techniques

Tracking pedestrian targets in forward-looking infrared video sequences is a crucial component of a growing number of applications. At the same time, it is particularly challenging, since image resolution and signal-to-noise ratio are generally very low, while the nonrigidity of the human body produces highly variable target shapes. Moreover, motion can be quite chaotic with frequent target-to-target and target-to-scene occlusions. Hence, the trend is to design ever more sophisticated techniques, able to ensure rather accurate tracking results at the cost of a generally higher complexity. However, many of such techniques might not be suitable for real-time tracking in limited-resource environments. This work presents a technique that extends an extremely computationally efficient tracking method based on target intensity variation and template matching originally designed for targets with a marked and stable hot spot by adapting it to deal with much more complex thermal signatures and by removing the native dependency on configuration choices. Experimental tests demonstrated that, by working on multiple hot spots, the designed technique is able to achieve the robustness of other common approaches by limiting drifts and preserving the low-computational footprint of the reference method.

In RFID systems, wireless communication among readers and tags is subject to electromagnetic interference. In particular, when several readers work closely, forming so-called Dense Reader Environment (DRE), reader-to-reader collisions may occur. Several anti-collision protocols have been proposed in the literature to address this issue. Distributed Color Selection (DCS) and Colorwave are two effective state-of-the-art protocols, based on Time Division Multiple Access (TDMA). DCS provides great fairness, but it is not adaptable to changes in network topology, penalizing the throughput of the network. Colorwave is an enhanced version of DCS offering more flexibility. Moreover, a general probabilistic approach has been suggested for solving collisions in TDMA protocols and, in particular, it has been applied to DCS. In this work, the probabilistic method is implemented in the collision resolution routine of Colorwave and its effects are analyzed, confirming the validity of this mechanism for TDMA protocols. As proved by simulation results, the probabilistic approach can be adopted to improve throughput or fairness, without adding any other requirement

Wireless sensor networks offer benefits in several applications but are vulnerable to various security threats, such as eavesdropping and hardware tampering. In order to reach secure communications among nodes, many approaches employ symmetric encryption. Several key management schemes have been proposed in order to establish symmetric keys. The paper presents an innovative key management scheme called Random seed distribution with transitory master key (RSDTMK), which adopts the random distribution of secret material and a transitory master key used to generate pairwise keys. The proposed approach addresses the main drawbacks of the previous approaches based on these techniques. Moreover, it overperforms the state-of-the-art protocols by providing always a high security level

Aim The exergy gradients are the sources of physical processes. Entropy quantifies the system's evolution toward increasingly more probable states, while entropy generation describes its irreversibility. The entropy generation approach is used to evaluate cells transport processes. The applied thermodynamic analysis of living systems points out that the geometrical characteristic, the chemical reaction rate and the time of chemical reactions are fundamental in the growth of cancer. Indeed, it has been highlighted that a cancer cell can modify its metabolism, so it is possible to measure the cell temperature variation with respect to peculiar ill states (1-3); indeed, the cellular metabolism can be studied by the analysis of the reactions of oxidation of the energy substrates. Materials and methods Energy transport phenomena occurs across the cell membrane, so this plays a fundamental role in the cell behaviour. Moreover, many processes in biological systems are related to nano-mechanical properties of cellular structures and membranes, therefore it is possible to argue that any external fields, which can act on the membrane electric and thermoelastic properties, could be worth to be investigated in relation to anticancer therapies. Results The cell membrane elastic vibration is one fundamental aspect of the cells elastic behaviour, and both phenomena are closely linked: the membrane elastic vibration originates variation in the membrane electric potentials, energy transport throughout the cell membrane could heavily be affected and, consequently, the internal cell organization could be influenced. Conclusions Magnetic field seems to play a strong influence on cells elastic behaviour and then on the energy transport throughout cell membranes. Metabolism of cancer cells is organized in order to export outside great amount of energy

Thin-walled open section beams are carefully analysed by Vlasov's theory of the sectorial areas. It allows to take into account their peculiar warping deformation which appears in presence of torsional actions. This behaviour determines a further stress state along the axis of the element which is rarely considered in structural analyses. The aim of the present paper is the evaluation of the warping deformation of thin-walled open section beams subjected to torsion. Firstly, the analytical theory proposed by Vlasov is verified through an experimental test on a steel specimen defined by a U profile. Specific analyses are performed with the aim of a sophisticated optical device in order to assess the transverse distortion of the section. Then, the results obtained experimentally and confirmed by a Finite Element (FE) program permit to validate a computer program based on the analytical theory and devised to study the structural behaviour of high-rise buildings stiffened by thin-walled open section shear walls. In order to evaluate the effectiveness of the program, an example which highlights the benefits provided by the present method compared to FE program is carried out.

One of the main challenges in automatic target tracking applications is represented by the need of maintaining a low computational footprint, especially when dealing with real-time scenarios and limited resources of embedded environments. In this context, significant results can be obtained by using forward looking infrared sensors capable of providing distinctive features for targets of interest. In fact, due to their nature FLIR images lends itself to be used with extremely small footprint techniques based on the extraction of target intensity profiles. This work proposes a method for increasing the computational efficiency of template-based target tracking algorithms. In particular, the speed of the algorithm is improved by using a dynamic threshold that narrows the number of computations, thus reducing both execution time and resources usage. The proposed approach has been tested on several datasets and it has been compared to several target tracking techniques. Gathered results, both in terms of theoretical analysis and experimental data, showed that the proposed approach is able to achieve the same robustness of reference algorithms by reducing the number of operations needed and the processing time

When moving in generic indoor environments, robotic platforms generally rely solely on information provided by onboard sensors to determine their position and orientation. However, the lack of absolute references often leads to the introduction of severe drifts in estimates computed, making autonomous operations really hard to accomplish. This paper proposes a solution to alleviate the impact of the above issues by combining two vision‐based pose estimation techniques working on relative and absolute coordinate systems, respectively. In particular, the unknown ground features in the images that are captured by the vertical camera of a mobile platform are processed by a vision‐based odometry algorithm, which is capable of estimating the relative frame‐to‐frame movements. Then, errors accumulated in the above step are corrected using artificial markers displaced at known positions in the environment. The markers are framed from time to time, which allows the robot to maintain the drifts bounded by additionally providing it with the navigation commands needed for autonomous flight. Accuracy and robustness of the designed technique are demonstrated using an off‐the‐shelf quadrotor via extensive experimental tests

Existing tracking methods designed for interacting with projection-based displays generally require visible artifacts to be introduced in the environment in order to guarantee effective stability and accuracy. For instance, in optical-oriented approaches, either the camera sensor or the reference pattern used for tracking are often located within the user's sight (or interfere with it), thus occluding portions of the scene or altering the perception of the virtual environment. Several ways to tackle these issues have been recently explored. Proposed approaches basically aim at making the presence of tracking references in the virtual space transparent to the user. However, such solutions introduce possibly critical constraints on required hardware or environment configuration. In this work, a novel tracking approach based on imperceptible fiducial markers is proposed. The approach relies on a hiding technique that allows digital images to be embedded in (and retrieved from) a projected scene by exploiting the properties of light polarization and additive color mixing. In particular, the virtual scene is obtained by overlapping the light beams of two projectors and by dealing with markers' hiding via color compensation. A prototype setup has been deployed, where interaction with a flat surface projection environment has been evaluated in terms of tracking accuracy and artifacts avoidance performance by using a consumer camera equipped with a polarizing filter. Although the performed tests presented in this article represent only a preliminary and a partial evaluation of the proposed approach, they provided encouraging results indicating that the proposed technique could be possibly applied in more complex interaction scenarios still with limited hardware requirements

Most virtual characters' animations are based on armatures to manipulate the characters' body parts (rigging). Armatures behave as the characters' skeletons, and their segments are referred to as bones. Each bone of the skeleton is associated with a well defined set of vertices defining the character' mesh (skinning), thus allowing animators to control movements and deformations of the character itself. This paper presents a natural and intuitive interface, which uses the Microsoft Kinect, to interactively control an armature by tracking body poses. Animators can animate virtual characters in real-time by their own body poses, thus obtaining realistic and smooth animations. Moreover, the proposed interface allows animators to save time with respect to the traditional animation technique based on keyframing. Different examples are used to compare the Kinect-based interface with the keyframing approach, thus obtaining both an objective and a subjective assessment.

This paper presents a new and challenging approach to the control of mobile platforms. Natural user interfaces (NUIs) and visual computing techniques are used to control the navigation of a quadrotor in GPS-denied indoor environments. A visual odometry algorithm allows the platform to autonomously navigate the environment, whereas the user can control complex manoeuvres by gestures and body postures. This approach makes the human-computer interaction (HCI) more intuitive, usable, and receptive to the user's needs: in other words, more user-friendly and, why not, fun. The NUI presented in this paper is based on the Microsoft Kinect and users can customize the association among gestures/postures and platform commands, thus choosing the more intuitive and effective interface

The reader-to-reader collision problem represents a research topic of great recent interest for the radio frequency identification (RFID) technology. Among the state-of-the-art anticollision protocols, the ones that provide high throughput often have special requirements, such as extra hardware. This study investigates new high throughput solutions for static RFID networks without additional requirements. In this paper, two contributions are presented: a new configuration, called Killer, and a new protocol, called distributed color noncooperative selection (DCNS). The proposed configuration generates selfish behavior, thereby increasing channel utilization and throughput. DCNS fully exploits the Killer configuration and provides new features, such as dynamic priority management, which modifies the performance of the RFID readers when it is requested. Simulations have been conducted in order to analyze the effects of the innovations proposed. The proposed approach is especially suitable for low-cost applications with a priority not uniformly distributed among readers. The experimental analysis has shown that DCNS provides a greater throughput than the state-of-the-art protocols, even those with additional requirements (e.g., 16 percent better than NFRA)

We introduce a mutual demagnetizing tensor for calculating the demagnetizing field in multiple magnetic bodies. Algorithms for magnetic simulations dealing with interactive n-bodies usually treat the simulation domain as a single non-homogeneous body with alternating magnetic and non-magnetic regions. Doing so minimizes the number of variables used in the field calculations, but the extra computation and storage requirements become very large. Our approach not only reduces memory consumption but also shows a gain in performance for cases involving field calculation in patterned films. We have verified our results by performing simulation of periodic dots of similar size arranged in grids of various formats

As the adoption of the radio-frequency identification (RFID) technology is increasing, many applications require a dense reader deployment. In such environments, reader-to-reader interference becomes a critical problem, so the proposal of effective anti-collision algorithms and their analysis are particularly important. Existing reader-to-reader anti-collision algorithms are typically analyzed using single interference models that consider only direct collisions. The additive interference models, which consider the sum of interferences, are more accurate but require more computational effort. The goal of this paper is to find the difference in accuracy between single and additive interference models and how many interference components should be considered in additive models. An in-depth analysis evaluates to which extent the number of the additive components in a possible collision affects the accuracy of collision detection. The results of the investigation shows that an analysis limited to direct collisions cannot reach a satisfactory accuracy, but the collisions generated by the addition of the interferences from a large number of readers do not affect significantly the detection of RFID reader-to-reader collisions.

In the recent years, new business models of provision of services are grown for different kind of software thanks to the development of cloud environments. A large number of companies use 3D software tools and can be interested in adopting 3D visualization as a functionality of the cloud infrastructure rather than the single employee's workstation, saving hardware resources and licenses costs. Remote visualization solutions allows to decouple computing resources on one side and visualization resources on the other side; rendering servers are in charge to compute and stream to the user's device the output graphics of the intended software as a sequence of individual frames. However, the provision of highly graphics-oriented software within a cloud can be particularly challenging due to a number of technological limitations from bandwidth requirements to latency-related issues. In this scenario, the calculation of the differences between successive frames (Diff-Map) is of paramount importance to reduce the bandwidth usage and computational complexity. Diff-Map calculation is time and resource consuming, therefore a method for the calculation of an approximated Diff-Map is proposed. This paper, after analyzing the main recent technological trends followed in the research domain for the development of effective remote visualization solutions, addresses the analysis of network bandwidth usage and computational speed by adopting approximated Diff-Map methods for encoding and transmitting only relevant data pertaining to changed areas of the frame buffer. A set of experimental tests demonstrates the savings in bandwidth consumption and performance speed up going towards a quality tradeoff, alleviating the burden of transmitting excessive useless data to remote client viewers.

The modular exponentiation on large numbers is computationally intensive. An effective way for performing this operation consists in using Montgomery exponentiation in the Residue Number System (RNS). This paper presents an algorithmic and architectural study of such exponentiation approach. From the algorithmic point of view, new and state-of-the-art opportunities that come from the reorganization of operations and precomputations are considered. From the architectural perspective, the design opportunities offered by well-known computer arithmetic techniques are studied, with the aim of developing an efficient arithmetic cell architecture. Furthermore, since the use of efficient RNS bases with a low Hamming weight are being considered with ever more interest, four additional cell architectures specifically tailored to these bases are developed and the tradeoff between benefits and drawbacks is carefully explored. An overall comparison among all the considered algorithmic approaches and cell architectures is presented, with the aim of providing the reader with an extensive overview of the Montgomery exponentiation opportunities in RNS.

In recent years, mobility of students and workers started to be considered as a way for answering skill shortages in the European labor world. However, in order to implement effective mobility practices, suitable instruments supporting transparency and readability of the outcomes of learning processes as well as of the needs of companies and employers in general have to be developed. In fact, though some instruments have been introduced (like, for instance, the European Qualification Framework, EQF, the European Credit system for Vocational Education and Training, ECVET, etc.), they are often seen as theoretical tools rather than a practical help for involved stakeholders. In this work, the results of the TIPTOE project, a transnational initiative funded by the European Commission under the Lifelong Learning Programme are illustrated. In particular, the semantic-based methodology for the construction of a European-wide profile mixing education and labor worlds perspectives in the trade sector is discussed. Furthermore, a number of tools allowing end-users to compare owned qualifications to the reference one and supporting stakeholders in the reading of national educational and occupational profiles in the EQF dimension are presented

This paper presents a comparative analysis of the three widely used parallel sorting algorithms: Odd-Even sort, Rank sort and Bitonic sort in terms of sorting rate, sorting time and speed-up on CPU and different GPU architectures. Alongside we have implemented novel parallel algorithm: min-max butterfly network, for finding minimum and maximum in large data sets. All algorithms have been implemented exploiting data parallelism model, for achieving high performance, as available on multi-core GPUs using the OpenCL specification. Our results depicts minimum speed-up19x of bitonic sort against odd-even sorting technique for small queue sizes on CPU and maximum of 2300x speed-up for very large queue sizes on Nvidia Quadro 6000 GPU architecture. Our implementation of full-butterfly network sorting results in relatively better performance than all of the three sorting techniques: bitonic, odd-even and rank sort. For min-max butterfly network, our findings report high speed-up of Nvidia quadro 6000 GPU for high data set size reaching 2^24 with much lower sorting time

Supply chain is a typical scenario of exploiting Radio Frequency Identification (RFID) technology. Its growing use in all the supply chain areas makes the presence of many close RFID readers more common. In such environment, interferences among readers are critical. Many protocols have been proposed to reduce reader-to-reader collisions. Experimental data showed that the Neighbor Friendly Reader Anticollision (NFRA) protocol [1] maximizes the network throughput. However, it does not take into account the delay between the request and the granting of query tags, causing delays for some readers. This paper proposes two approaches to increase the fairness and ensure a high throughput for each reader. A theoretical analysis, supported by experimental simulations, demonstrates the improvements achieved

Wireless communication advances have enabled emerging video streaming applications to mobile handheld devices. For example, it is possible to display and interact with complex 3D virtual environments on mobile devices that don't have enough computational and storage capabilities (e.g. smart phones, PDAs) through remote rendering techniques, where a server renders 3D data and streams the corresponding image flow to the client. However, due to fluctuations in bandwidth characteristics and limited mobile device CPU capabilities, it is extremely challenging to design effective systems for streaming interactive multimedia over wireless networks. This paper presents a novel approach based on a controller that can automatically adjust streaming parameters basing on feedback measures from the client device. Experimental results prove the effectiveness of the proposed solution in coping with bandwidth changes, thus providing high Quality of Service (QoS) in remote visualizations

The wide adoption of radio frequency identification (RFID) for applications requiring a large number of tags and readers makes critical the reader-to-reader collision problem. Various anti-collision protocols have been proposed, but the majority require considerable additional resources and costs. Distributed color system (DCS) is a state-of-the-art protocol based on time division, without noteworthy additional requirements. This paper presents the probabilistic DCS (PDCS) reader-to-reader anti-collision protocol which employs probabilistic collision resolution. Differently from previous time division protocols, PDCS allows multichannel transmissions, according to international RFID regulations. A theoretical analysis is provided in order to clearly identify the behavior of the additional parameter representing the probability. The proposed protocol maintains the features of DCS, achieving more efficiency. Theoretical analysis demonstrates that the number of reader-to-reader collisions after a slot change is decreased by over 30%. The simulation analysis validates the theoretical results, and shows that PDCS reaches better performance than state-of-the-art reader-to-reader anti-collision protocols

PURPOSE: To describe and test a new fully automatic lesion detection system for breast DCE-MRI. MATERIALS AND METHODS: Studies were collected from two institutions adopting different DCE-MRI sequences, one with and the other one without fat-saturation. The detection pipeline consists of (i) breast segmentation, to identify breast size and location; (ii) registration, to correct for patient movements; (iii) lesion detection, to extract contrast-enhanced regions using a new normalization technique based on the contrast-uptake of mammary vessels; (iv) false positive (FP) reduction, to exclude contrast-enhanced regions other than lesions. Detection rate (number of system-detected malignant and benign lesions over the total number of lesions) and sensitivity (system-detected malignant lesions over the total number of malignant lesions) were assessed. The number of FPs was also assessed. RESULTS: Forty-eight studies with 12 benign and 53 malignant lesions were evaluated. Median lesion diameter was 6 mm (range, 5-15 mm) for benign and 26 mm (range, 5-75 mm) for malignant lesions. Detection rate was 58/65 (89%; 95% confidence interval [CI] 79%-95%) and sensitivity was 52/53 (98%; 95% CI 90%-99%). Mammary median FPs per breast was 4 (1st-3rd quartiles 3-7.25). CONCLUSION: The system showed promising results on MR datasets obtained from different scanners producing fat-sat or non-fat-sat images with variable temporal and spatial resolution and could potentially be used for early diagnosis and staging of breast cancer to reduce reading time and to improve lesion detection. Further evaluation is needed before it may be used in clinical practice.

The new generation of high-performance decimal floating-point units (DFUs) is demanding efficient implementations of parallel decimal multipliers. In this paper, we describe the architectures of two parallel decimal multipliers. The parallel generation of partial products is performed using signed-digit radix-10 or radix-5 recodings of the multiplier and a simplified set of multiplicand multiples. The reduction of partial products is implemented in a tree structure based on a decimal multioperand carry-save addition algorithm that uses unconventional (non BCD) decimal-coded number systems. We further detail these techniques and present the new improvements to reduce the latency of the previous designs, which include: optimized digit recoders for the generation of 2(n)-tuples (and 5-tuples), decimal carry-save adders (CSAs) combining different decimal-coded operands, and carry-free adders implemented by special designed bit counters. Moreover, we detail a design methodology that combines all these techniques to obtain efficient reduction trees with different area and delay trade-offs for any number of partial products generated. Evaluation results for 16-digit operands show that the proposed architectures have interesting area-delay figures compared to conventional Booth radix-4 and radix-8 parallel binary multipliers and outperform the figures of previous alternatives for decimal multiplication

The customer mostly chooses a product on the base of its quality, which therefore arises as the main cause of its commercial success. In a nearly axiomatic drawing, it follows that the effect of innovation is the improvement of quality, which itself becomes the aim of innovation. Even though the previous statement relates quality and innovation, it still does not explain their dynamics. To stress them, the ‘quality' concept must be analyzed in more detail. In fact, in addition to the ‘perceived quality', the quality ensured through `design, manufacturing and marketing' combined domains should be dealt with. This paper enhances this issue taking advantage of principles and models made available by control theory schemes coupled with quality function development (QFD) and best practice software modeling based on unified modeling language (UML)

This paper presents a system to track position and orientation of a generic mobile device equipped with a camera using a set of variable size fiducial markers. The system provides six degrees-of-freedom (6-DOF) by tracking fiducial markers through the camera and deriving the position and orientation of the device, thus making possible the implementation of innovative and affordable 3D user interfaces. The system has been integrated in a Cave Automatic Virtual Environment (CAVE) through the use of projectors and polarizers.

RFID is a well-known pervasive technology, which provides promising opportunities for the implementation of new services and for the improvement of traditional ones. However, pervasive environments require strong efforts on all the aspects of information security. Notably, RFID passive tags are exposed to attacks, since strict limitations affect the security techniques for this technology. A critical threat for RFIDbased information systems is represented by data tampering, which corresponds to the malicious alteration of data recorded in the tag memory. The aim of this paper is to describe the characteristics and the effects of data tampering in RFID-based information systems, and to survey the approaches proposed by the research community to protect against it. The most important recent studies on privacy and security for RFID-based systems are examined, and the protection given against tampering is evaluated. This paper provides readers with an exhaustive overview on risks and defenses against data tampering, highlighting RFID weak spots and open issues

The rapid growth in the number of conferences and papers appearing in conference proceedings publications has increased the need to examine the issue of conference paper quality. Since conference content is included in permanent repositories, such as IEEE's Xplore, the existence of low-quality papers in a conference will degrade the value and reputation of the conference and the repository. The aim of this contribution is to consider these issues from the point of view of the Conference Publications Operations Committee of the IEEE Computer Society, and offer ideas that could lead to improved conference publishing quality for all IEEE societies and even non-IEEE entities

With the tremendous growth of information available to end users through the Web, search engines come to play ever a more critical role. Nevertheless, because of their general-purpose approach, it is always less uncommon that obtained result sets provide a burden of useless pages. The next-generation Web architecture, represented by the Semantic Web, provides the layered architecture possibly allowing overcoming this limitation. Several search engines have been proposed, which allow increasing information retrieval accuracy by exploiting a key content of Semantic Web resources, that is, relations. However, in order to rank results, most of the existing solutions need to work on the whole annotated knowledge base. In this paper, we propose a relation-based page rank algorithm to be used in conjunction with Semantic Web search engines that simply relies on information that could be extracted from user queries and on annotated resources. Relevance is measured as the probability that a retrieved resource actually contains those relations whose existence was assumed by the user at the time of query definition

Automatic target tracking in forward-looking infrared (FLIR) imagery is a challenging research area in computer vision. This task could be even more critical when real-time requirements have to be taken into account. In this context, techniques exploiting the target intensity profile generated by an intensity variation function (IVF) proved to be capable of providing significant results. However, one of their main limitations is represented by the associated computational cost. In this paper, an alternative approach based on genetic algorithms (GAs) is proposed. GAs are search methods based on evolutionary computations, which exploit operators inspired by genetic variation and natural selection rules. They have been proven to be theoretically and empirically robust in complex space searches by their founder, J. H. Holland. Contrary to most optimization techniques, whose goal is to improve performances toward the optimum, GAs aim at finding near-optimal solutions by performing parallel searches in the solution space. In this paper, an optimized target search strategy relying on GAs and exploiting an evolutionary approach for the computation of the IVF is presented. The proposed methodology was validated on several data sets, and it was compared against the original IVF implementation by Bal and Alam. Experimental results showed that the proposed approach is capable of significantly improving performances by dramatically reducing algorithm processing time

Tracking targets in forward-looking infrared (FLIR) video sequences taken from airborne platforms is a challenging task. Several tracking failure modes can occur; in particular, discontinuities due to platform's motion can produce the so called ego-motion failure leading to unrecoverable errors in tracking the target. A novel ego-motion compensation technique for UAVs (unmanned aerial vehicles) is proposed. Data received from the autopilot can be used to predict the motion of the platform, thus allowing to identify a smaller region of the image (subframe) where the candidate target has to be searched for in the next frame of the sequence. The presented methodology is compared with a recently robust algorithm for automatic target tracking; experimental results show that the proposed motion estimation approach helps to improve performance both in terms of frames processed per second (targets are searched in smaller regions) and in terms of robustness (targets are correctly tracked for all the sequence's frames)

Traceability is a key factor for the agri-food sector. RFID technology, widely adopted for supply chain management, can be used effectively for the traceability management. In this paper, a framework for the evaluation of a traceability system for the agri-food industry is presented and the automation level in an RFID-based traceability system is analyzed and compared with respect to traditional ones. Internal and external traceability are both considered and formalized, in order to classify different environments, according to their automation level. Traceability systems used in a sample sector are experimentally analyzed, showing that by using RFID technology, agri-food enterprises increase their automation level and also their efficiency, in a sustainable way

A radix-2 digit-recurrence algorithm and architecture for the computation of the cube root are presented in this paper. The original recurrence based on the concept of completing the cube is modified to allow an efficient implementation of the algorithm and the cycle time and area cost of the resulting architecture are estimated as 7.5 times the delay of a full adder and around 9,000 nandl cells, respectively, for double-precision computations

This framework lets users easily and effectively use desktop applications on mobile devices without any redesign. An automatically generated description of the original interface lets the original application be recreated and migrated to nomadic scenarios. Users can also customize interfaces to suit their needs and match a device's capabilities

A general digit-recurrence algorithm for the computation of the mth root (with an m integer) is presented in this paper. Based on the concept of completing the mth root, a detailed analysis of the convergence conditions is performed and iterationindependent digit-selection rules are obtained for any radix and redundant digit set. A radix-2 version for mth rooting is also studied, together with closed formulas for both the digit selection rules and the number of bits required to perform correct selections

Scientific research and practical applications of solar physics require data and computational services to be integrated seamlessly and efficiently. The European Grid for Solar Observations (EGSO) leverages Grid-oriented concepts and technology to provide a high-performance infrastructure for solar applications. In this paper, an architecture for a data brokerage service is proposed. Brokers interact with providers and consumers in order to build a profile of both parties. In particular, a broker interacts with providers in order to gather information on the data potentially available to consumers, and with the consumers in order to identify the set of providers that are most likely to satisfy specific data needs. The brokerage technique is based on a multi-tier management of metadata

Mobile devices such as Personal Digital Assistants, Tablet PCs, and cellular phones have greatly enhanced user capability to connect to remote resources. Although a large set of applications are now available bridging the gap between desktop and mobile devices, visualization of complex 3D models is still a task hard to accomplish without specialized hardware. This paper proposes a system where a cluster of PCs, equipped with accelerated graphics cards managed by the Chromium software, is able to handle remote visualization sessions based on MPEG video streaming involving complex 3D models. The proposed framework allows mobile devices such as smart phones, Personal Digital Assistants (PDAs), and Tablet PCs to visualize objects consisting of millions of textured polygons and voxels at a frame rate of 30 fps or more depending on hardware resources at the server side and on multimedia capabilities at the client side. The server is able to concurrently manage multiple clients computing a video stream for each one; resolution and quality of each stream is tailored according to screen resolution and bandwidth of the client. The paper investigates in depth issues related to latency time, bit rate and quality of the generated stream, screen resolutions, as well as frames per second displayed

Recently the authors have observed in compounds of the 4,n-alkyloxybenzoic acid series, with the homologous index n ranging from 6 to 9, a texture transition in the nematic range which subdivides the nematic phase in two sub-phases displaying different textures in polarised light analysis. To investigate a persistence of texture transitions in nematic phases, we prepared binary mixtures of 4,6-alkyloxybenzoic acid (6OBAC) with other members (7-, 8-, 9-, 12-, 16OBAC) of its homologous series. Binary mixtures exhibit a broadening in the temperature ranges of both smectic and nematic phases. A nematic temperature range of 75C is observed. In the nematic phase, in spite of the microscopic disorder introduced by mixing two components, the polarised light optics analysis of the liquid crystal cells reveals a texture transition. In the case of the binary mixture of 6OBAC with 12OBAC and with 16OBAC, that is of compounds with monomers of rather different lengths, the texture transition temperature is not homogeneous in the cell, probably due to a local variation in the relative concentrations of compounds.

Global and local histogram equalization (HE) proved to be effective techniques for contrast enhancement. Local HE allows to achieve high contrast enhancement rates but its high computational complexity limits its applicability in many resource constrained scenarios. On the contrary, global HE complexity is relatively low but enhancement rate is often unsatisfactory. Recently, an algorithm exploiting a low-pass filter (LPF) mask to obtain a partially overlapped sub-block HE effect (POSHE) has been presented. POSHE allows to produce the high local HE contrast with the simplicity of global HE. In this paper a generalization of POSHE approach exploiting cascaded multistep binomial filtering HE (CMBFHE) in order to get the same LPF mask is proposed. By relying on the same filter mask, contrast enhancement capability of CMBFHE is exactly the same of POSHE. Additionally, results show that a significant speedup with respect to the previous fastest method is achieved because of the efficient implementation of the filtering approach; moreover hardware implementations can be effectively designed. This makes CMBFHE a suitable solution in all those consumer electronics related environments including camcorders, digital cameras and video surveillance where on-the-fly local-like contrast enhancement is required

The 4,n-alkyloxybenzoic acid 6OBAC has a very rich variety of crystalline structures and two nematic sub-phases, characterised by different textures. It is a material belonging to a family of liquid crystals formed by hydrogen bonded molecules, the 4,n-alkyloxybenzoic acids (n indicates the homologue number). The homologues with 7 <= n <= 13 display both smectic C and N phases. In spite of the absence of a smectic phase, 6OBAC exhibits two sub-phases with different textures, as it happens in other materials of the homologue series which possess the smectic phase. This is the first material that exhibits a texture transition in a nematic phase directly originating from a crystal phase. Here we present the results of an image processing assisted optical investigation to characterise the textures and the transitions between textures. This processing is necessary to discriminate between crystal modifications and nematic sub-phases.

In this paper, we propose a class of division algorithms with the aim of reducing the delay of the selection of the quotient digit by introducing more concurrency and flexibility in its computation. From the proposed class of algorithms, we select one that moves part of the selection function out of the critical path, with a corresponding reduction in the critical path compared with existing alternatives. We present the algorithm and describe the architectures for radix 4 and for radix 16. For radix 16, we use the scheme of overlapping two radix-4 stages. In both cases, radix 4 and radix 16, we show that our algorithms allow the design of units with well-balanced critical paths with consequent decreases of the cycle times. Moreover, in the radix-16 case, we include some additional speculation techniques. To estimate the speedup, we used a rough timing model based on logical effort. For both radices, we estimate a speedup of about 25 percent with respect to previous implementations. In the radix-4 case, this is achieved by using roughly the same area, while, in the radix-16 case, the area is increased by about 30 percent. We verified our estimations by performing a synthesis of the radix-4 units.

In video encoding, block motion estimation represents a CPU-intensive task. For this reason, many fast algorithms have been developed to improve searching and matching phases. A milestone within the lossless approach is partial distortion elimination (PDE/SpiralPDE) in which distortion is the difference between the block to be coded and the candidate prediction block. In this paper, (i) we analyze distortion behavior from local information using the Taylor series expansion and show that our general analysis includes other previous similar approaches. (ii) Then, we propose two full-search (lossless), fast-matching, block motion estimation algorithms, based on the PDE idea. The proposed algorithms, called fast full search with sorting by distortion (FFSSD) and fast full search with sorting by gradient (FFSSG), sort the contributions to distortion and the gradient values, respectively, in order to quickly discard invalid blocks. Experimental results show that the proposed algorithms outperform other existing full search algorithms, reducing by up to 20% the total CPU encoding time (with respect to SpiralPDE), while the computation strictly required by the motion estimation is reduced by about 30%. (iii) Finally, we experimentally find an operational lower bound (based on standard test sequences) for the average number of checked pixels in the PDE approach, which measures the performance of the searching and matching phases. In particular, SpiralPDE achieves performances very close to the searching phase bound, while there is still a remarkable margin on the matching phase. We then show that our algorithms, aimed at improving the performances of the matching phase, achieve interesting results, significantly approaching this margin.

A basic mesoscopic model of MTS growth is proposed. Taking advantage of the spherical symmetry, the model allows to fully explore the parameter space and investigate alternative interaction mechanisms, in view also of comparisons with macroscopic \"universal laws\". Preliminary results are in good agreement with available experimental data.

Block motion estimation represents a cpu-intensive task in video encoding and many fast algorithms have been developed to improve the searching and matching phases. A milestone within the lossless approach is partial distortion elimination (PDE/SpiralPDE) in which distortion is the difference between the block to be coded and the candidate prediction block. In this paper we show that contributions to distortion can be reliably estimated using the Taylor series expansion. The approximation method is then used to derive eight new PDE-based algorithms in which the matching order depends on the magnitude of the estimated distortion contributions. Exhaustive comparisons using several, widely different, video sequences show that these algorithms reduce the total encoding time by up to 20% with respect to SpiralPDE, while the computation for motion estimation is reduced by about 30%. The proposed algorithms are also compared with other PDE-based lossless approaches known in literature and there is a significant gain over all of them

This paper describes a hybrid distributed architecture, based on the JXTA technology, for searching and discovering data in a federation of solar observation archives. This work has been developed within the European project EGSO (European Grid of Solar Observations) with the intent of studying and analyzing a set of technologies and showing the brokerage capabilities of a highly controlled distributed network topology. Three roles have been identified: providers that contain data and metadata, brokers that manage providers and user queries, and consumers/clients. JXTA is used to develop all network system functionalities, while a native XML database is used to store resource descriptions.

In recent years many experimental investigations have been carried out on vasculogenesis and angiogenesis, the mechanisms of blood vessels formation. Neovascularization is a hallmark of embryogenesis and many other physiological processes, such as wound healing or endometrium vascularization during the mestrual cycle. Angiogenesis also plays a key role in tumor growth, tumor metastasis and other pathological processes including many inflammatory diseases. Understanding biological phenomena regulating angiogenesis is therefore essential for clinical treatment of cancer and other angiogenesis-dependent diseases. This paper describes the development of a fully-automated computerized angiogenesis analysis system, which enables angiogenesis parameters to be quantified in an in-vitro model. The proposed methodology works on phase contrast microscopy snap photographs of cultured endothelial cell plates, and extracts a detailed graph-based representation of the blood vessels network thus supporting accurate angiogenesis parameters measurement

An extension of the very-high radix division with prescaling and selection by rounding is presented. This extension consists of increasing the effective radix of the implementation by obtaining a few additional bits of the quotient per iteration, without increasing the complexity of the unit to obtain the prescaling factor or the delay of an iteration. As a consequence, for some values of the effective radix, it permits an implementation with a smaller area and the same execution time of the original scheme. Details of the algorithm and the implementation are presented. Estimations of the execution time and area are given for 54 bit and 114 bit quotients and compared with those of other division units

The visualization of dense vector fields has important applications for scientific purposes. Beyond the standard methods, such as arrows and particle tracing, texture-based methods are able to show almost all the details of a field. This paper presents the Thick Oriented Stream-Line (TOSL) algorithm, which can show direction, orientation and local flow speed even for dense vector fields by simulating the convolution process. A practical comparison of the performances of TOSL vs. other visualizations algorithms (LIC and fastLIC) shows that the proposed algorithm can provide output textures faster than the other considered techniques.

An algorithm for square root with prescaling and selection by rounding is developed and combined with a similar scheme for division. Since division is usually more frequent than square root, the main concern of the combined implementation is to maintain the low execution time of division, while accepting a somewhat larger execution time for square root. The algorithm is presented in detail, including the mathematical development of bounds for the first square-root digit and for the scaling factor. The proposed implementation is described, evaluated and compared with other combined div/sqrt units. The comparisons show that the proposed scheme potentially produces a significant speed-up for division, whereas, for square root, the speed-up is small

his paper presents a new algorithm to generate ray-cast CSG animation frames. We consider sequences of frames where only the objects can move; in this way, we take advantage of the high screen area coherence of this kind of animation. A new definition of bounding box allows us to reduce the number of pixels to be computed for the frames after the first. We associate a CSG subtree and two new flags, denoting if the box has changed in the current frame and if it will change in the next frame, with each box. We show with three examples the advantages of our technique when compared with an algorithm which entirely renders each frame of an animation. Intersections with CSG objects may be reduced to about one-fifth, while the rendering may be computed up to four times faster for the test sequences

The generation of 3-D solid objects, and more generally solid geometric modelling, is very important in Computer Aided Design (CAD). An important role is played by the Constructive Solid Geometry (CSG) representation scheme. IN CSG, objects are described by trees of Boolean operations on half-spaces or boundaries of primitive solids. The study of techniques to speed up the rendering of scenes modelled with the CSG scheme is an attractive field of research; in this paper we propose a new algorithm which reduces the computational complexity for ray casting approaches. Our strategy identifies a set of areas on the plane of view where the rays starting from the observer have to be traced; for each zone, only a portion of the entire CSG tree has to be considered for intersection tests, instead of the whole database of the primitive objects. A comparison of our algorithm with a ray caster that adopts bounding volume hierarchies and with a freeware ray tracer called POV-Ray shows that, for the examples considered, we may reduce the intersection tests to one third of those performed when standard optimizations are adopted.

Carry-save multipliers require an adder at the last step to convert the carry-sum representation of the most significant half of the result into a non-redundant form. This paper presents n×n multiplication schemes where this conversion is performed with a circuit operating in parallel with the carry-save array. The most relevant feature of the proposed multipliers is that the full 2n-bit result is produced, unlike similar multiplication schemes presented in the literature

The authors present a parallel algorithm for fast rendering. A set of zones which can be concurrently processed is identified; this set is split into a number of subsets equal to the number of available processors. Each processor renders, in parallel with the others, a zone of its set

The paper analyses an SRT radix-B division algorithm where the determination of the quotient digits is performed in parallel with the updating of the residual. The authors do not use any prescaling digit prediction (in order to reduce the complexity of the selection function) as it is done using other prediction-based techniques. The authors present application examples of radix-2 (and radix-4, briefly) division design using their prediction scheme, and compare them with the `classical' SRT radix-2, radix-4 and radix-16 schemes without prediction. They estimate that the proposed algorithm achieves execution times comparable to the computation delay of the `classical' SRT radix-B 2 division algorithm without prediction, but requires less hardware

In a previous paper by P. Montuschi and L. Ciminiera (ibid., vol. 42, no.2 p239-246, Feb 1993), an architecture for shared radix 2 division and square root has been presented whose main characteristic is the ability to avoid any addition/subtraction, when the digit 0 has been selected. Here, we emphasize the characteristics of the digit selection mechanism used by Montuschi and Ciminiera by presenting a small modification of the digit selection hardware, which has the benefit to further reduce the computation delay with respect to the time estimated in that work

Several computer graphics algorithms (such as ray-tracing) heavily relate their performances to the efficiency of the tests of intersection between the rays of a light source and the objects of a synthetic scene. Some solid modelling and robotics algorithms need also to test quickly the possible interferences of the different parts of a system such as the arms of different robots. To speed-up the test, the free shape objects to be tested are encapsulated into boxes and the test starts by performing a check on overlapping of the bounding boxes, thus producing a section of the space where an intersection can occur. Successively, if the boxes overlap, the test continues on the original free shape objects, but only in the portion of the 3D-space resulting from the first step. The authors present a simple, fast and efficient algorithm (called the `bounding boxes group' method) to compute a tight bounding entity of a complex object modelled in the constructive solid geometry (CSG). If no upper limit is set to the number of elements of each bounding box group, the algorithm is shown to achieve the tightest possible solution. Algorithms are also presented which allow a reduction of the number of bounding elements but still provide a satisfactory and tight encapsulation

The advantages of the convergence with the square of the Newton-Raphson method are combined with the precision characteristics of digit-by-digit algorithms to obtain units for fast division that satisfy the IEEE 754 floating point standard requirements. A general design methodology that leads to a class of alternative architectures providing interesting performances for division is presented, together with one example of possible implementation. In particular, the proposed implementation achieves a speedup varying from 20% to about 30% in comparison with a previous architecture by Fandrianto, with a relatively small additional hardware cost if a multiplier is already available on the arithmetic unit

Over-redundant digit sets are defined as those ranging from -s to +s, with s⩾B, B being the radix. This paper presents new techniques for the direct computation of division, that use an over-redundant digit set for representing the quotient, instead of simply redundant ones used previously. In particular, general criteria for synthesizing the digit selection rules and remainder updating are given for any radix and index of redundancy. A methodology combining the use of over-redundant digit sets with the prescaling of the divisor is also studied in order to achieve radix-B division units with trivial digit selection functions. It is also shown, for the specific case of radix-4 that using a prescaling slightly wider than in a radix-4 unit by M.D. Ercegovac and T. Lang (1990) possible to avoid the digit selection table. The paper also presents a modified algorithm for on-the-fly conversion of the result into the irredundant form. The proposed methodology can be considered as an alternative to existing division techniques

We present a radix-8 divider that uses an over-redundant digit set for the quotient in order to obtain simple digit selection rules. We show that the proposed enlarged set of values for the quotient digit does not lead to increases both in the complexity and the delay of the adder required to update the remainder, with respect to similar solutions, since the values allowed for the quotient digit have been selected carefully. The digit selection process is subdivided into two concurrent steps, each one making reference to a secondary digit set and the resulting implementation can be cheaper and faster than other units which do not use over-redundant digit sets. A performance analysis estimates a speed improvement from 25% to 35% with respect to a radix-8 architecture by Fandrianto, and from 21% to 30% with respect to a radix-4 architecture with prescaling, presented by Ercegovac and Lang. As required from the IEEE 754 floating point standard, the proposed algorithm features the correct remainder of the division.

A division algorithm in which the quotient-digit selection is performed by rounding the shifted residual in carry-save form is presented. To allow the use of this simple function, the divisor (and dividend) is prescaled to a range close to one. The implementation presented results in a fast iteration because of the use of carry-save forms and suitable recodings. The execution time is calculated and several convenient values of the radix are selected. Comparison with other dividers for radices 2^9 to 2^18 is performed using the same assumptions

A new architecture is presented for shared radix 2 division and square root whose main characteristic is the ability to avoid any addition/subtraction, when the digit 0 has been selected. The solution presented uses a redundant representation of the partial remainder, while keeping the advantages of classical solutions. It is shown how the next digit of the result can be selected even when the remainder is not updated, and the subsequent tradeoff is presented. The proposed architecture is also extended in order to consider other implementations

A radix 4 division architecture is presented which partially overlaps the updating of the remainder with the digit selection procedure. It is obtained by separating the radix 4 digit selection process into two concurrent substeps. The proposed unit requires a simple selection table and involves a small extra expense for the additional hardware compared to the usual radix 4 division units. Four possible implementations are derived from the general model, with different types of substeps. The high level evaluation shows that the proposed architectures offer an efficient alternative

A scheme for performing higher radix square root based on prescaling of the radicand is presented to reduce the complexity of the result-digit selection. The scheme requires several steps, namely multiplication for prescaling the radicand, square root, multiplication for prescaling for the division, and division. Online algorithms are used to reduce the overall time and pipelining to reuse the different modules. An estimate of the execution time for a radix-256 unit for double-precision square root and a comparison with other implementations indicate that the proposed approach is an alternative to consider when designing a square-root unit

A general approach for designing units for higher-radix division is outlined which is based on several subunits operating in parallel. A lower-radix-division unit is used as the building block of the architecture, and the division step is split into two phases which are carried out in parallel. It is shown that the proposed architecture permits the design of units for higher-radix division with digit-selection tables requiring only few supplementary input bits with respect to the tables used by lower-radix division systems.

Timed token protocols have increased in importance with the growth of local area network (LAN) communications One of the most important timed token protocols is certainly IEEE 802.4, a standard given the name 'token bus', which represents one of the most interesting solutions to the problem of handling, on the same physical channel, the transmission of messages belonging to multiple priority classes. In the paper, the authors study some time characteristics of the IEEE 802.4 protocol, giving bounds to the mean and the maximum duration of a complete token cycle. It is shown how these results can be conveniently used by a network designer to tune the parameters that characterise an IEEE 802.4 local area network

The problem of obtaining optimal starting values for the calculation of square root using Newton-Raphson's Method is considered. This paper presents the best starting values theory in order to optimize the maximum absolute error after a given number of iterations. Two different methods are shown, and a third, which can be considered as a mixture of the previous two, is briefly discussed. The approach combines analytical and numerical methodologies, which gives more interesting results on the main characteristics of the behavior of the absolute error for different initializations. A comparison table between the traditional optimal relative error results and the absolute error ones is provided.

Two classes of systolic architectures are presented that are able to compute bicubical B-spline or Bezier polynomial coefficients and carry out polynomial evaluations. Using a pair of full arrays it is possible to compute all the coefficients in parallel, and to evaluate the polynomials for a given surface, as well as provide a speedup factor of more than 1500 compared with the single processor computation. An alternative solution is to partition both tasks into smaller sub-tasks so that a reduced size of the array is required. This allows a reasonable tradeoff between the speed needs and the VLSI implementation requirements to be achieved.

A general discussion on nonrestoring square root algorithms is presented, showing bounds and constraints delimiting the space of feasible algorithms, for all the choices of radix, digit set and representation of the partial remainder. Two classes of algorithms are then derived from the general discussion, and it is shown how it is possible to determine two parameters with a relevant impact on the implementation: the number of radicand bits to be inspected in order to obtain a starting value, and the number of partial remainder bits to be examined for digit selection. The algorithms for the specific case of radix 4 digit set {-2, -1, 0, +1, +2}, and partial remainder represented in carry-save form are derived in order to show that the algorithms introduced can lead to better results than those obtained with algorithms previously presented

Minimum requirements for the high-priority token holding time (HPTHT) in a network using timed token access protocols (such as IEEE 802.4 and FDDI) are derived in order to ensure that the throughput of synchronous messages is no lower than the amount of traffic generated for that class. The minimal value is essential in order to avoid unbounded queue length for the synchronous class as well as to achieve high network responsiveness. The results have been obtained for synchronous messages generated according to a generic periodic pattern with no constraint for the shape and for the period of the pattern. The manner in which the theoretical results obtained can be used to tune the network performance is also shown

Timed-token protocols are used to handle, on the same local area network, both real-time and non-real-time traffic. The authors analyze this type of protocol, giving worst-case values for the throughput of non-real-time traffic and the average token rotation time. Results are obtained for synchronous traffic generated according to a generic periodic pattern under heavy conditions for non-real-time traffic and express not only theoretical lower bounds but values deriving from the analysis of some real networks. A model which addresses the asynchronous overrun problem is presented. The influence of introducing multiple priority classes for non-real-time traffic on the total throughput of this type of message is shown. It is also shown that the differences between the values obtained under worst-case assumptions are close to those obtained under best-case assumptions; the method may therefore be used to provide important guidelines in properly tuning timed-token protocol parameters for each specific network installation

An architecture based on the Inmos T800 transputer is presented in this paper that is able to compute the bicubical polynomial coefficients for surfacesmodeling in computer graphics. The Occam tasks for the Bezier surfacemodelingalgorithm are discussed, both in the case of a full array, consisting of 256 transputers, and for a partitioned solution using 16 T800's. In particular, the problem of assigning the different tasks to the processors has been considered, showing how our solution can be easily tailored to the hardware resources available.

Some performance results obtained by simulating the behavior of a local area network based on the IEEE 802.5 standard are presented. The simulation model has been designed to evaluate the mean response time observed by the user of the LLC (logical link control) service, instead of measuring the turnaround time experienced by the medium access control user; i.e. the performance index is the average delay between the message generation and the receipt of the corresponding acknowledgement. Type-3 LLC service is analyzed since it appears particularly attractive in industrial LANs concerned with real-time activities and adopting reduced protocol profiles. The effect of having different priority classes for the messages in the network system has been studied. Some results that demonstrate the existence of a practical upper bound to the maximum value of the token holding time have been obtained

In a multicore environment, a major focus is represented by synchronization. Since synchronization mechanisms strongly affect the performance of multithread algorithms, the selection of an effective synchronization approach is critical for multicore environments. In this chapter, the cost of the main existing synchronization techniques is estimated. The current investigation covers both hardware and software solutions. A comparative analysis highlights benefits and drawbacks of the considered approaches. The results are intended to represent a useful aid for researchers and practitioners interested in optimization of parallel algorithms.

Unintentional falls are a frequent cause of hospitalization that mostly increases health service costs due to injuries. Fall prediction systems strive to reduce injuries and provide fast help to the users. Typically, such systems collect data continuously at a high speed through a device directly attached to the user. Whereas such systems are implemented in devices with limited resources, data volume is significantly important. In this chapter, a real-time data analyzer and reducer is proposed in order to manage the data volume of fall prediction systems.

Learning semantics, which is intended as a way to provide digital learning resources with a meaning and make them processable by machines by mimicking human reasoning, is changing the way teaching and learning processes are being carried out. Through semantic processing, a machine could act as a personal assistant at the service of learners, trainers and other actors involved in the education context, and could help them to address knowledge-intensive problems, encompassing the creation, management and personalization of learning paths, the identification of suitable learning resources, the automatic grading of assignments and exams, etc. This paper aims to draft an overall picture of learning semantics, by illustrating enabling technologies, providing hints on how a semantic system for learning could be realized, presenting relevant application scenarios, showing expected benefits, discussing challenges and threats and outlining possible solutions.

Brain injury can cause a variety of physical effects and cognitive deficits. Although it has not yet been systematically adopted in clinical settings, virtual reality promises to be an excellent therapeutic tool for regaining both locomotor and neurological capacities. This work presents the design and implementation of VR2 (Virtual Reality Rehabilitation), a customizable rehabilitation framework intended to enable the creation of motivating rehabilitation scenarios based on an ecologically valid semi-immersive system. Following the implementation phase, a study to test the acceptability of VR2 in a group of subjects with cerebral lesions was conducted to investigate the usability of the framework. The group consisted of 11 people from 22 to 70 years of age, who were divided into two groups depending on the chronicity of disorder. The adequacy of the interface between patient and system was verified through questionnaires containing subjective questions, which revealed good overall acceptance and enjoyment of the tool. Moreover, to obtain early results useful for tuning the overall system in preparation for rigorous clinical trials, a set of preliminary cognitive tests concerning the rehabilitation protocol was conducted within the same group. Although the preliminary findings are promising and reveal a positive trend in neurocognitive investigations, the system should undergo clinical trials before being used in real clinical settings.

The spread of robotics in many sectors of human life is driving researchers to focus more and more on human-robot interaction (HRI). This multidisciplinary field addresses all of the issues related to the interaction between robots and people. HRI incorporates contributions from artificial intelligence, cognitive science, human factors, psychology and social science, among others. This paper provides a summary of the main themes of HRI from the point of view of both technology and the user experience.

Pedestrian detection and tracking constitutes a key element of many intelligent video systems in different application areas, in particular for video surveillance, driving assistance, advanced manufacturing automation, and video indexing and retrieval tasks. Each particular application domain poses significant and, sometimes, different challenges to this task (e.g., applications with static or dynamic cluttered backgrounds, recognition in poor lighting conditions, and occlusion management). For this reason, a considerable amount of literature has been produced in the past to cope with a majority of the given issues. This entry presents the reader with an overview of recent detection and tracking approaches by focusing on their role in computer vision applications, analyzing the associated main challenges, and how they are currently addressed.

Division is one of the basic arithmetic operations supported by every computer system. The operation can be performed and implemented in either hardware or software, or a combination of the two. Although division is not as frequent as addition and multiplication, nowadays most processors implement it in hardware to not compromise the overall computation performances. In this note, we explain the basic algorithms, suitable for hardware and software, to implement division in computer systems. Two classes of algorithms implement division or square root: digit-recurrence and multiplicative (e.g., Newton-Raphson) algorithms. The first class of algorithms are of digit-recurrence type, and are especially suitable for hardware implementation as they require modest resources and provide good performance on contemporary technology. The second class of algorithms, multiplicative type, requires significant hardware resources and is more suitable for software implementation on the existing multiply units. The purpose of this note is to provide an introductory survey using a presentation style suitable for reading also by the interested non-specialist Readers.

The technological development that has taken place over recent years has affected the way that the Web is exploited by users. In fact, a user is no longer seen as a mere observer; instead, he or she actively takes part in the production of new knowledge, which is then made available to other users. In this scenario, which is characterized by ever-growing information, new approaches (e.g., based on semantic technologies) for processing large amounts of content must be developed. Other sectors, including education and learning, as well as job seeking and hiring activities, could benefit from the exploitation of tools that can be developed within the Semantic Web initiative. As a consequence of the use of semantic technologies, learners could find more efficient training paths that provide them with their missing areas of competence and training institutes could analyze and modify existing qualifications according to a market's requirements, while companies could effectively identify the best candidates for a given job, not only within national boundaries but also worldwide. This study aims to present an overview of recent research in the field of semantic technologies applied to education and job-seeking contexts. Issues that are related to students' and workers' mobility, job seeking and hiring and the improvement of qualification offers will be analyzed and compared, by distinguishing three fields of research: knowledge base creation, the development of strategies for the integration of heterogeneous systems and the definition of inference rules, and the identification of methodologies for the visualization of qualification outcomes and curricula

[101103.EG ISBN 9781420077773 altra opera \"RFID and sensor networks : architectures, protocols, security, and integrations\". 9781420068399 altro ISBN valido]

The goal of desktop-class graphics hardware is generally to provide the maximum performances possible to end users. This goal is shared also by mobile hardware designers, although, due the use of a battery as power source, a greater attention needs to be devoted to energy saving. In the last years, a number of approaches to hardware design have been experimented aimed to trade-off the quality of the visual experience with the usage of computational resources, that is to say, with energy consumption. The objective of this work is to tackle energy issues at the software, i.e., at the application level, by introducing a high-level library based on OpenGL ES (often abbreviated GLES) that can be exploited by developers to create energy-aware graphics applications letting end users chose the maximum amount of energy to consume.

The increasing popularity of unmanned aerial vehicles (UAVs) in critical applications makes supervisory systems based on the presence of human in the control loop of crucial importance. In UAV-traffic monitoring scenarios, where human operators are responsible for managing drones, systems flexibly supporting different levels of autonomy are needed to assist them when critical conditions occur. The assessment of UAV controllers' performances thus their mental workload may be used to discriminate the level and type of automation required. The aim of this paper is to build a mental-workload prediction model based on UAV operators' cognitive demand to support the design of an adjustable autonomy supervisory system. A classification and validation procedure was performed to both categorize the cognitive workload measured by ElectroEncephaloGram signals and evaluate the obtained patterns from the point of view of accuracy. Then, a user study was carried out to identify critical workload conditions by evaluating operators' performances in accomplishing the assigned tasks. Results obtained in this study provided precious indications for guiding next developments in the field.

In recent years, unmanned aerial vehicles have received a significant attention in the research community, due to their adaptability in different applications, such as surveillance, disaster response, traffic monitoring, transportation of goods, first aid, etc. Nowadays, even though UAVs can be equipped with some autonomous capabilities, they often operate in high uncertainty environments in which supervisory systems including human in the control loop are still required. Systems envisaging decision-making capabilities and equipped with flexible levels of autonomy are needed to support UAVs controllers in monitoring operations. The aim of this paper is to build an adjustable autonomy system able to assist UAVs controllers by predicting mental workload changes when the number of UAVs to be monitored highly increases. The proposed system adjusts its level of autonomy by discriminating situations in which operators' abilities are sufficient to perform UAV supervision tasks from situations in which system suggestions or interventions may be required. Then, a user study was performed to create a mental-workload prediction model based on operators' cognitive demand in drone monitoring operations. The model is exploited to train the system developed to infer the appropriate level of autonomy accordingly. The study provided precious indications to be possibly exploited for guiding next developments of the adjustable autonomy system proposed.

Commercial off-the-shelf (COTS) robots are becoming ever more ubiquitous. Among the most common applications there are toy robots. In order to keep their cost down, these robots are usually equipped with the minimum set of sensors necessary for their basic functioning. Specifically, to add entertainment value, they often feature a video camera and, in most of the games developed so far, players are basically tele-operating them through a smartphone app. The present paper aims to show how to provide existing consumer-grade robots with new capabilities to transform them in more appealing gaming companions. In particular, by considering as a test bench a wheeled, non-holonomic COTS robot whose only accessible sensor is a low-resolution camera, previously unavailable localization and autonomous navigation capabilities are developed for it by exploiting dead reckoning and artificial landmark detection algorithms. These capabilities could then be exploited to create new types of games, which can be played in free-scale unknown environments and feature new forms of interaction. Implementation details of a sorting game in which the robot acts as a referee are reported.

Continuous advancements in the field of robotics and its increasing spread across heterogeneous application scenarios make the development of ever more effective user interfaces for human-robot interaction (HRI) an extremely relevant research topic. In particular, Natural User Interfaces, e.g., based on hand and body gestures, proved to be an interesting technology to be exploited for designing intuitive interaction paradigms in the field of HRI. However, the more sophisticated the HRI interfaces become, the more important is to provide users with an accurate feedback about the state of the robot as well as of the interface itself. In this work, an Augmented Reality (AR)-based interface is deployed on a head-mounted display to enable tele-operation of a remote robot team using hand movements and gestures. A user study is performed to assess the advantages of wearable AR compared to desktop-based AR in the execution of specific tasks.

The use of virtual reality (VR) is widespread in a growing number of application domains. Continuous technological advancements in the field of computer graphics made VR an interesting tool for learning purposes, especially in sport. Examples can be found in different sports such as rugby, baseball, soccer, golf, etc. This paper presents a VR-based training system that can be used as a self-learning tool to improve the execution of a given technical gesture. In particular, the basketball free throw gesture is considered. To assess the usefulness of the proposed system, experimental tests were carried out in a small-scale setup by involving 18 non-skilled volunteers. Results demonstrated that the designed system can improve the execution of the considered gesture in terms of both timing and spatial positioning compared to an alternative technique based on video projection.

Providing an effective cognitive aid to both lay people and healthcare providers in Basic Life Support and Defibrillation (BLSD) procedures is a relevant educational goal in resuscitation. A self-instruction learning simulation program was developed to maximize learning results, helping to enhance motor skills and the retention of cognitive knowledge, reduce instructor intervention and cost. Microsoft HoloLens technology was used, enabling users to interact with high definition holograms. Holo-BLSD was developed as a mixed reality (MR) self-instruction training environment allowing also assessment, using a standard low-cost CPR manikin to deliver tactile information. The manikin was \"augmented\" by an interactive virtual environment reproducing realistic scenarios. Learners used natural gestures, body movements and spoken commands to perform their tasks, with virtual 3D objects anchored to the manikin and to the environment. We believe such a project is the first in the domain of BLSD.

Approximate high radix dividers (HR-AXDs) are proposed and investigated in this paper. High-radix division is reviewed and inexact computing is introduced at different levels. Design parameters such as number of bits (N) and radix (r) are considered in the analysis; the replacement of exact cells with inexact cells in a binary signed-digit adder is introduced by utilizing different replacement schemes. Cell truncation and error compensation are also proposed to further extend inexact computation. Circuit-level performance and the error characteristics of the inexact high radix dividers are analyzed for the proposed designs. The combined assessment of the normal error distance, power dissipation and delay is investigated and applications of approximate high-radix dividers are treated in detail. The simulation results show that the proposed approximate dividers offer extensive saving in terms of power dissipation, circuit complexity and delay, while only incurring in a small degradation in accuracy thus making them possibly suitable and interesting to some applications and domains such as low power/mobile computing.

Using digital instruments to support artistic expression and creativity is a hot topic. In this work, we focused on the design of a suitable interface for Augmented Reality-based constructive art on handheld devices. Issues to be faced encompassed how to give artists sense of spatial dimensions, how to provide them with different tools for realizing artworks, and how much moving away from ``the real'' and going towards ``the virtual''. Through a touch-capable device, such as a smartphone or a tablet, we offer artists a clean workspace, where they can decide when to introduce artworks and tools. In fact, besides exploiting the multi-touch functionality and the gyroscopes/accelerometers to manipulate artworks in six degrees of freedom (6DOF), the proposed solution exploits a set of printed markers that can be brought into the camera's field of view to make specific virtual tools appear in the augmented scene. With such tools, artists can decide to control, e.g., manipulation speed, scale factor, scene parameters, etc., thus complementing functionalities that can be accessed via the device's screen.

The continuous progress in the field of robotics and the diffusion of its related application scenarios in today's modern world makes human interaction and communication with robots an aspect of fundamental importance. The development of interfaces based on natural interaction paradigms is getting an increasingly captivating topic in Human-Robot Interaction (HRI), due to their intrinsic capabilities in providing ever more intuitive and effective control modalities. Teleoperation systems require to handle a non-negligible amount of information coming from on-board sensors as well as input devices, thus increasing the workload of remote users. This paper presents the design of a 3D User Interface (3DUI) for the control of teleoperated robotic platforms aimed at increasing the interaction efficiency. A hand gesture driven controller is used as input modality to naturally map the position and gestures of the user's hand to suitable commands for controlling the platform components. The designed interface leverages on mixed reality to provide a visual feedback to the control commands issued by the user. The visualization of the 3DUI is superimposed to the video stream provided by an on-board camera. A user study confirmed that the proposed solution is able to improve the interaction efficiency by significantly reducing the completion time for tasks assigned in a remote reach-and-pick scenario.

A 3D User Interface for manipulating virtual objects in Augmented Reality scenarios on handheld devices is presented. The proposed solution takes advantage of two interaction techniques. The former (named ``cursor mode'') exploits a cursor, which position and movement are bound to the view of the device; the cursor allows the user to select objects and to perform coarse-grain manipulations by moving the device. The latter (referred to as ``tuning mode'') uses the physical affordances of a tangible interface to provide the user with the possibility to refine objects in all their aspects (position, rotation, scale, color, and so forth) with a fine-grained control

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The preparation of a set for a television production is a complex work; usually, several objects have to be manually placed in the environment and the configuration might be changed many times before finding the final set up. This configuration phase can be expensive and time consuming when large and heavy objects have to be moved. In order to tackle this issue, virtual sets allow the director of production to create virtual scenes before placing real objects. This paper proposes an alternative approach based on augmented reality technologies: objects of the scene are computer generated assets, which can be placed and manipulated in a real environment. With respect virtual sets, the proposed solution allows the director to move in a real scene enriched by computer-generated objects to be placed in the environment. The user wears an AR headset and manipulates objects by a tablet. The proposed system was evaluated by a group of 9 testers, which had to create an augmented TV set. Subjective and objective parameters have been used to assess the system usability.

In the last years, robotic telepresence solutions have received a significant attention from both the commercial and academic worlds, due to their ability to allow people to feel physically present at a remote place and move in it. Operating a mobile robot with some autonomous capabilities from distance can enable a wide range of mass-market applications, encompassing teleconferencing, virtual tourism, etc. In these scenarios, the possibility to interact with the robot in a natural way becomes of crucial importance. The aim of this paper is to investigate, through a comparative analysis, the usability of two major approaches used today for controlling telepresence robots, i.e., keyboard and point-and-click video navigation. A control system featuring the above interfaces plus a combination of the two has been developed, and applied to the operation of a prototype telepresence robot in an office scenario. The system additionally includes functionalities found in many research and industry solutions, like map-based localization and \"augmented\" navigation. Then, a user study has been performed to assess the usability of the various control modalities for the execution of some navigation tasks in the considered context. The study provided precious indications to be possibly exploited for guiding next developments in the field.

Augmented Reality (AR) is expected to change the way we play, by transforming the world around us in an incredibly rich gaming environment. In this work, connected robots and natural interaction means are combined with projected AR to create a gaming experience more physical and engaging.

Ongoing emphasis on the fourth industrial revolution requires further focus on the Internet of Things (IoT) as a means to integrate all relevant entities within a single technological system. In the integration process, a gateway to relay the raw data to an IoT endpoint is essential so that a joint interface among the heterogeneous domains can be provided. This work describes the development of a distributed industrial IoT gateway, called DIIG, able to relay industrial network data to a centralized data-store. DIIG exploits a real-time client server programming model based on S7 communication and Modbus TCP protocols. The subsequent analysis carried out on the testbed mainly focuses on the performance evaluation of the gateway. In order to achieve high performance data transmission in a fair environment, a parallel real-time communication mechanism has been proposed.

Human gait is a dynamic biometrical feature that describes the kinematics of human walking. Gait modeling is studied in order to find a pattern of walking that can be used for diagnosis of walking disorder or abnormal walk detection. Difficulty in walking progressively increases with aging and causes unintentional falls, which is a common incident among elderly people. Fall prediction systems can help to prevent unintentional falls that could cause serious injuries, therefore they can reduce the health service costs. This paper presents an algorithm with polynomial classification model of human gait for real-time fall prediction. This approach enables the user to detect the transition from a normal to an abnormal walking pattern. A dataset based on the state-of-the-art techniques in simulating abnormal walks was created by using an accelerometer embedded in a smartphone, which is recognized to be precise enough for fall avoidance systems. The proposed approach improves state-of-the-art fall prediction approaches, by achieving 99.2% of accuracy in abnormal walk detection.

Guaranteeing the correct system behaviour in safety-critical computer-based systems is a challenging issue due to transient faults. This has been demonstrated considering the effects of faults in memory elements containing data structures belonging to a Unix-based Operating System. Elements linked to resource and process synchronization management are particularly critical, thus the need for hardening also the kernel data structures. In order to overcome this vulnerability, a solution is proposed by implementing a triplication technique in the source code of the Linux kernel, aiming at incrementing the robustness of the system. An experimental fault injection analysis has been conducted on the Mutex semaphores to evaluate its effectiveness. The proposed approach successfully detected and corrected the noxious effects generated by single faults in the system with a limited performance overhead.

Urban air quality strongly affects the health of citizens. In recent years, much effort has been spent in improving air quality monitoring systems in order to provide detailed data that consider the variability over the whole urban area. In order to improve the spatial accuracy of the monitoring systems, wireless sensor networks and pervasive technologies have been exploited. However, these systems normally do not consider vertical variability. Nonetheless, in buildings, people at a high floor may breath air with different characteristics with respect to those at ground floor. The goal of this paper is to investigate the variability of the dust level according to the height. An experimental analysis has been conducted and the achieved results confirm the importance of height for air quality and people health and highlight the importance of further studies.

The paper presents a methodology for the automatic abstraction of analog magnetic components to achieve efficient simulation of complex smart system virtual platform. We aim at facilitating the validation process by allowing the simulation of both functional and extra-functional behaviors of the system with an unified simulation environment. The approach employs a process of simplification which removes unnecessary details of the analog model, enabling a much faster simulation.

The ability to plan a training path fulfilling working needs plays a key role, when it comes to finding the desired job. Nonetheless, in a dynamic scenario characterized by frequent technological innovations and economic changes, as the present one, getting a clear picture of the requirements of the world of work could become difficult, as it would imply performing a deep periodic evaluation of available job offers, and matching them with own previous experience. Intelligent systems able to automatically match résumés with job offers already exist, but they are mostly targeted to recruiters, instead of learners. This work aims at filling this gap, by presenting a system for comparing learners' acquirements - expressed in terms of learning outcomes - with companies requirements. The proposed system relies on semantics for processing natural language texts and exploits bar charts to visualize learning outcomes and their levels in order to quickly depict similarities and differences between résumés and job offers. An evaluation, conducted on 50 volunteers, underlined the added value of the system.

Interacting with 3D contents is a challenging task and the implementation of natural and effective interfaces is usually demanded to computer programmers. On the other hand, exhibit designers would greatly take advantage of graphic tools able to completely hide technical details and code programming. This paper presents a graphic editor where interface designers can intuitively link objects, gestures and actions together, without needing computer science skills. Tests show the advantages of the proposed solution both for experts and beginners; moreover, a real example concerning the exhibit of the digital Nefertiti's bust within a holographic case controlled by hand gestures has been implemented.

The increasing popularity of robotics and related applications in modern society makes interacting and communicating with robots of crucial importance. In service robotics, where robots operate to assist human beings in their daily life, natural interaction paradigms capable to foster an ever more intuitive and effective collaboration between involved actors are needed. The aim of this paper is to discuss activities that have been carried out to create a 3D immersive simulation environment able to ease the design and evaluation of natural human-robot interfaces in generic usage contexts. The proposed framework has been exploited to tackle a specific use case represented by a robotics-enabled office scenario and to develop two user interfaces based on augmented reality, speech recognition as well as gaze and body tracking technologies. Then, a user study has been performed to study user experience in the execution of semi-autonomous tasks in the considered scenario though both objective and subjective observations. Besides confirming the validity of the devised approach, the study provided precious indications regarding possible evolutions of both the simulation environment and the service robotic scenario considered.

Several virtual and augmented reality tasks involve users in hands-free interactions; in this case, speech-based systems are often preferred for their intuitiveness and naturalness. On the other hand, the robustness of this kind of interfaces can be an issue, thus affecting both the usability and the user experience, when they are used in noisy environments. This paper proposes a one switch interface triggered by vocal commands: three different scanning algorithms are tested. With this kind of interface users can sequentially select the desired command, thus improving the robustness of traditional speech recognition-based interfaces. Latency time is an issue for one switch interfaces, but it is shown how a bidirectional scanning algorithm based on a non binary switch can strongly mitigate this problem. Vocal one switch (VOS) interfaces are compared with a traditional multi-word speech interface both objectively (in terms of robustness and efficiency) and subjectively (user feedback).

The authors are currently doing fatigue tests, by using sonotrodes working at 20 kHz, and compression tests on solid samples of rock materials. The specimens are monitored by laser sources focused on spots of the external surface. The main purpose is to identify in the crystal lattice mechanical oscillations in a frequency range higher than the Acoustic Emission (kHz) and comprised between MHz and THz. Such vibrational modes in the THz regime will be the signature of developing anomalies in piezoelectric or piezomagnetic materials, such as neutron and/or alpha particle emissions, and compositional changes. Moreover, it is also known that laser current pulses should be effective in exciting vibrational modes in the high-frequency range in conductive samples. A photodetector connected to an usual oscilloscope, measuring the intensity of reflected light, detects vibrations in the range from MHz up to few GHz. To reduce the limitations in the ability to acquire high frequency signals, additional experiments are planned exploiting the Raman effect. Through the scattered light spectrum analysis, capable of detecting radiation in the visible light field, it should be obtained information on the intermolecular interactions that during solicitations induce resonant vibrations in the field of THz

Fall datasets usually record normal activities and transitions from one posture to another one with falls. Many fall detection datasets based on different sensors are adopted by researchers to improve their systems. Although fall avoidance are dramatically increasing, a public fall prediction and prevention dataset based on an accelerometer and gyroscope is absent. So, this study creates a dataset based on the state-of-the-art techniques in simulating a fall. Different techniques are evaluated to find the best fall simulation. Since accelerometer and gyroscope sensors embedded in a smartphone are recognized to be suited for fall avoidance systems, in this study, they are used to obtain data from users. At the end, some statistical analysis of the observed data are presented and a nonlinear regression model is proposed.

Predicting a fall is one of the most promising approaches to avoid it. Different studies strive to classify abnormal and normal walks in order to predict a fall before its occurrence. This study introduces eigenwalk, a novel feature based on the principal components of the accelerometer and gyroscope signals. This feature, in conjunction with a random forest classifier, is able to distinguish walk patterns and to estimate a fall risk. As the accelerometer and the gyroscope embedded in a smartphone are recognized to be precise enough for fall avoidance systems, they have been exploited in an experimental analysis in order to compare the proposed approach with the most recent ones. The results have shown that the new feature in combination with the random forest classification outperforms state-of-the-art approaches, by improving the accuracy up to 98.6%

This paper discusses the phenomenon of energy emissions from brittle specimens subjected to resonant ultrasound vibration. The aim is to describe and demonstrate the neutron emissions from piezonuclear reactions that have been recently observed for the first time and published in [1-3], providing new experimental evidences. In addition to some natural brittle rocks, as considered in the previous studies, sintered ceramic samples are studied. The energy release during ultrasound vibration is assessed by continuously monitoring the electric power input, the temperature of the specimen, as well as the neutron emission by means of He3 devices and bubble detectors. As a result, the energy balance can be estimated, suggesting that an extra energy amount is generated due to the piezonuclear phenomena involved

Although the acceleration is physically related to the displacement of an object, i.e., to its change of position, it is demonstrated that the double integration of the acceleration does not provide accurate information about the displacement, due to the noise and measurement errors. This paper evaluates a correction technique based on the Kalman filter in order to increase the accuracy of the estimation of the displacement. Experiments were performed by acquiring the acceleration with an off-the-shelf accelerometer: the percentage error made by simply integrating the acceleration measurements may arrive to 68% in the general case of a movement in the space, but it can be dramatically reduced to 9% with the proposed approach. An even better behavior is obtained when the movement is constrained to a plane or along an axis

Traditional database systems either sacrifice availability or partitionability at the cost of offering strict consistency guarantee of data. However, the significant growth of Web-scale applications and the wider array of emerging workloads demand revisiting the need for full transactional consistency. One new dominant class of workload is the ability to efficiently support single statement transaction consisting of either Get or Put operation; thus, simplifying the consistency model. These simple workloads have given rise to decade-long efforts for building efficient key-value stores that often rely on disk-resident and log-structured storage model that is distributed across many machines. To further expand the scope of key-value stores, in this paper, we introduce Kanzi, a distributed, in-memory key-value stored over shared-memory architecture enabled by remote direct memory access (RDMA) technology. The simple data and transaction model of our proposed Kanzi additionally may serve as a generic (embedded) caching layer to speed up any disk-resident data-intensive workloads.

Terahertz vibrations at the nanoscale could provide a common basis to study mechanical instabilities both in crystalline solids and biological materials. As a matter of fact, dynamic instabilities induced in the crystal lattices of solids during brittle fracture, as well as protein folding and unfolding might produce THz resonant vibrations. By using the scattered light spectrum analysis, the authors are performing experimental studies to obtain information about the molecular interactions in crystalline solids and protein structures. These analyses can be useful to understand which kind of excitation should be applied to produce resonant vibrations in the field of THz. Simplified numerical models are also being implemented to interpret the variations in the crystal lattices natural frequencies of compressed solids, and to simulate buckling/snap-through nano-instabilities of specific proteins

Fall avoidance systems reduce injuries due to unintentional falls, but most of them are fall detections that activate an alarm after the fall occurrence. Since predicting a fall is the most promising approach to avoid a fall injury, this study proposes a method based on new features and multilayer perception that outperforms state-of-the-art approaches. Since accelerometer and gyroscope embedded in a smartphone are recognized to be precise enough to be used in fall avoidance systems, they have been exploited in an experimental analysis in order to compare the proposal with state-of-the-art approaches. The results have shown that the proposed approach improves the accuracy from 83% to 90%.

In today's world, large volumes of medical data are being continuously generated, but their value is severely undermined by our inability to translate them into knowledge and, ultimately, actions. Data mining techniques allow the extraction of previously unknown interesting patterns from large datasets, but their complexity limits their practical diffusion. Data-driven analysis is a multi-step process, in which health care professionals define analysis goals and assess extracted knowledge, while computer scientists tackle the non trivial task of driving the miner system analysis activity. This paper addresses the mining activity from a different perspective. We believe that mining systems should be able to devise which knowledge could be most interesting to users and extract actionable knowledge from large medical datasets, with minimal user intervention. More specifically, mining systems should be capable of (i) devising viable end-goals for a specific dataset (i.e., that yield actionable knowledge to the user and are feasible given the dataset characteristics and size), based on the expertise acquired during the analysis of previous datasets, and (ii) extracting a manageable set of knowledge. Automated data analysis should fuel the next generation of medical mining systems, thus enabling users to automatically mine massive data repositories

Drone-based delivery of goods could become a reality in the near future, as witnessed by the increasing successful experiences in both research and commercial fields. In this paper, a prototype system exploiting a do it yourself quad copter drone for delivering products is proposed. On the one hand, the hardware choices made in order to limit risks arising from autonomous delivery are presented. On the other hand, a framework for orders placement and shipment is shown. The advantages of a system like the one described in this paper are mainly related to an increased delivery speed, especially in urban contexts with traffic, to the possibility to make deliveries in areas usually difficult to be reached, and to the drone's ability to autonomously carry out consignments. A practical use case, in which the proposed system is used for delivering drugs (an application in which the need to quickly receive the good might be particularly important) is shown. Nevertheless, the proposed prototype could be employed in other contexts, such as take-away deliveries, product shipments, registered mail consignments, etc

The availability of annotated multimedia contents is a crucial requirement for a number of applications. In the context of education it could support the automatic summarization of recorded lessons or the retrieval of learning material. In the field of entertainment, it could serve to recommend audio and video resources based on user's attitudes. In this work, a framework supporting video viewing experience augmentation on mobile devices by means of image- and text-based annotations extracted on-demand from Wikipedia is presented. Speech recognition is exploited to periodically get text snaps from the audio track of the video currently displayed on the mobile device, while query-by-images is used to generate a text summary of extracted video frames. Keywords obtained are treated by semantic techniques to find named entities associated with the multimedia contents, which are then superimposed to the video and displayed to the user in a synchronized way. Promising results obtained with a prototype implementation showed the feasibility of the proposed solution, which could be possibly combined with other systems, e.g., providing information about user's location, preferences, etc. to build up more sophisticated context-aware applications

The aim of the project is to design and develop a system, a framework and a \"cultural heritage storytelling model\" to ease the exploitation of transmedia storytelling in the promotion of cultural heritage, through the reuse of European digital cultural assets. It will provide institutions and enterprises with a powerful environment to design and develop transmedia contents and to improve the promotion of their activities. A transmedia model will be applied in order to engage citizens and tourists in narrative experiences, online and in physical spaces (test sites will be equipped in Greece, Italy, Bulgaria), improving their knowledge of values deeply connected with European identity, such as work, social equality, natural resources exploitation. This objective is accomplished through the design of a fictional open and expandable narrative universe created through research and historical documentation. Alternate reality Games, Augmented Reality, Game App, Immersive cinematic and Virtual reality will be among the technologies applied in StoryTECH. A Semantic Reasoner will be designed and developed to improve the reuse of digital archives by a wider audience and to provide authoring support to transmedia storytelling of cultural heritage. StoryTECH will develop also an Animation Framework in order to ease the production of multimedia contents by small institutions and SME.

This paper studies the opportunities coming from the use of consumer devices like smartphones and tablets to perform maintenance and assembly procedures with Augmented Reality (AR). Pros and cons are evaluated by comparing completion times and errors made while executing a maintenance procedure with an AR-based tool and paper-based instructions

Augmented Reality (AR) has been proved to be an effective tool to improve and enhance the learning experience of students. On the other hand, issues regarding the inflexibility of AR contents can strongly limit the usability of AR applications in education. This paper presents results obtained by using the AR framework designed and developed for the EASE-R3 European project and focused on the generation of maintenance procedures for machine tools. The high system flexibility allows instructors to easily make maintenance procedures suitable for the skill level of technicians to be trained. A case study is presented and results gathered so far analyzed and assessed

The fast pace of change in high technology product development requires high flexibility and adaptation in product design and technology management. Within this context, appropriate learning environments are planned to shape future Information and Communication Technology staff in such a way they could get able to keep up with new trends and innovations. A constructivist educational model based on Active Learning represents a step towards this vision for staff training. This paper deals with a new organization of a 13 weeks course based on the inverted class model, where students are introduced to the problem-posing domain by a direct involvement of enterprises, which participate specifically to the problem definition and assessment phases. In the case study shown, students simulate a production business unit in all the phases that characterize the product/service development life cycle. A mixed traditional and company-based organization of the course is supposed to improve students competences by proposing solutions leveraging on appropriate tools taken from traditional experiences and also gaining benefits from a learning-by-doing approach that encourages the use of state-of-the-art solutions. A preliminary study is performed to see how expected professional competences are met during the course, with the additional goal of collecting indications that could help to improve the learning framework for future editions of the course

Knowing how users interact with Web contents is essential in order to design more effective Web pages and sites. A way to get the data needed for studying Web activity is via analytics tools that, given the amount of information to be processed, generally support the interpretation of results via graphics representations of either raw or aggregated data. With aggregated data, it is quite common to use heat maps, i.e., visual diagrams where colors can depict, among others, the amount of clicks/taps on a given region of the Web page or the areas that are reached more frequently when the page is scrolled. However, existing viewport-based solutions are not designed to aggregate data about the areas that received users' attention when page visualization may change from one device to another. In this paper, a framework capable to support a better understanding of a Web page as a unique information container by collecting information about mobile users' activity on multiple devices and visualizing it in an aggregated map on a per-element rather than a per-region basis is reported.

The analysis of thin-walled open section beams can be performed by means of Vlasov's theory of the sectorial areas. It is well-known that this type of profiles, when subjected to torsional actions, are characterised by the warping deformation and, consequently, by a further stress state whose intensity is comparable with that produced by mere flexural deformations. In the literature many papers are focused on the structural behaviour of these elements, but, to the Author's best knowledge, none proposed an experimental technique to evaluate first-hand this particular behaviour. In order to verify the classical theory of the sectorial areas, in the present paper an experiment regarding a thin-walled open section profile subjected to flexural and torsional loads is performed. With the help of a specific optical device, suitable for precision measurements, the warping displacements of a U-shaped section are easily acquired. These are compared to those derived, first, from an analytical formulation, originally devised to deal with vertical thin-walled bracings belonging to the structural core of a tall building, and, secondly, from a FE program, in which the steel profile is modelled by means of thin-shell elements. The numerical comparison confirms the reliability of the analytical formulation.

Radio Frequency Identification (RFID) is a widely employed technology for automatic identification. However, it is affected by some interference issues. This paper is focused on the interference between Ultra high frequency (UHF) RFID systems and devices that communicate according to the Global System for Mobile Communications (GSM) standard. Since the GSM and the UHF RFID frequency bands are close, the mobile phones communication can affect the efficiency of RFID systems. In this paper, an experimental analysis on the interference between GSM and UHF RFID is presented. The results of the experimentation highlight the negative effects of the use of GSM devices in the proximity of operating UHF RFID systems. Moreover, the main elements that should be taken into account during the design of an RFID system that works in the same area with GSM devices are identified

The elastic energy released by micro-cracking yields to macroscopic fracture whose mechanical vibrations are converted into electromagnetic (EM) oscillations over a wide range of frequencies, from few Hz to MHz, and even up to microwaves. As regards Acoustic Emission (AE), the classical monitoring techniques allow an observation over a range of frequencies up to hundreds of kHz. In this paper the authors investigate if, during compression tests on brittle materials, which involve catastrophic fractures, it is possible to identify in the stressed materials mechanical oscillations in a frequency range higher than that characteristic of the AE and comprised between MHz and THz. This excited state of matter could be a precursor of subsequent resonance phenomena of nuclei able to produce neutron bursts, especially in the presence of sudden catastrophic fractures. This phenomenon has been also very recently argued from a theoretical physical point of view by Widom et al. In this investigation experimental evidences emerge by means of a confocal sensor able to measure the resonance frequency of the specimen. The basic idea is to use a laser light focused onto a spot of the specimens surface subjected to mechanical compression. A photo-detector measures the intensity of the reflected light and then gives the frequency variation that is proportional to the vibration frequency of the spot particles.

Besides revealing useful information, like gender, age, existing impairments, the gait of every person is acknowledged to be so distinctive to allow the personal identification and it is regarded as a valid biometric authentication, similarly to fingerprinting and face recognition. Although the first analyses on the gait were conducted in laboratories with dedicated equipment, portable sensors have been exploited as they become available thanks to the technology miniaturization. Aiming at an even more unobtrusive analysis, recent proposals rely on the data acquired from the 3-axis accelerometer embedded in most of the smartphones commercially available on the market. Nevertheless the analysis must be tailored to the lower-grade accelerometer and the limited computational capability of the smartphone. This paper identifies the guidelines that the state-of-the-art research proposes for the gait recognition through a smartphone and discusses the procedures that are found as more appropriate.

Nowadays, the air quality is considered a key point, and its monitoring is not only suggested but it is even required in many countries. Since traditional standard monitors for air quality are very expensive, the use of a low-cost distributed network of sensors represents a valid complementary approach. This paper discusses the benefits of a distributed approach and analyzes the main elements that should be taken into account during the design of a distributed system for the air quality monitoring. This paper aims at representing a valuable aid for researchers and practitioners interested in the topic

Reader-to-reader interference affects the simultaneous activity of the readers in an RFID system: the collisions among the readers penalize the throughput and the reliability of the application. Many reader-to-reader anti-collision protocols have been proposed to address this issue. Their performance is generally evaluated by means of simulations. For this purpose, a generic simulator of wireless networks is exploited in most of the cases. This paper proposes a novel simulator, which is customized to the characteristics of the RFID technology in order to speed up the evaluation of anti-collision protocols. The simulator is based on OMNeT++ and it adds new ad-hoc facilities, such as the implementation of the existing reader-to-reader anti-collision protocols and a modular architecture for rapidly developing and testing new ones

Augmented Reality (AR) applications are nowadays largely diffused in many fields of use, especially for entertainment, and the market of AR applications for mobile devices grows faster and faster. Moreover, new and innovative hardware for human-computer interaction has been deployed, such as the Leap Motion Controller. This paper presents some preliminary results in the design and development of a hybrid interface for hand-free augmented reality applications. The paper introduces a framework to interact with AR applications through a speech and gesture recognition-based interface. A Leap Motion Controller is mounted on top of AR glasses and a speech recognition module completes the system. Results have shown that, using the speech or the gesture recognition modules singularly, the robustness of the user interface is strongly dependent on environmental conditions. On the other hand, a combined usage of both modules can provide a more robust input.

This paper presents a new architecture supporting the development of enhanced reading applications. It exploits the thin-client paradigm to let the authors produce interactive components to be embedded in today e-books, thus enriching text contents with focused and customized graphics widgets generated from the interface of existing programs running in remote

Students and learners mobility is more and more becoming a praxis. Nonetheless, despite the legislative efforts carried out by the European Commission, devoted to the definition of standards for describing qualifications, the comparison of qualifications contents, for instance in the phases of identification of more suitable training to attend abroad, or during the recognition of prior learning, still requires a considerable amount of efforts and time. This difficulty could be mainly attributed to the fact that qualification contents are usually expressed heterogeneously. In this work, a way to tackle this heterogeneity, by relying on a semantic thesaurus for graphically displaying main similarities and dissimilarities among qualifications is presented. By means of such representation, users could quickly become aware of the main characteristics of a training course, with respect to the others, without having to read all the textual information related to them

The widespread adoption of mobile devices is giving everyone access to augmented reality systems, possibly involving a huge number of people in AR-based apps, with a pervasive social impact that cannot be neglected. AR systems are becoming affordable to everyone and especially useful in the maintenance field. This report aims to describe in a clear and accessible way the workflow to design and develop an augmented reality (AR) application for supporting maintenance procedures. The main focus of this paper is the evaluation of markerless tracking systems, as they could provide environment-independent solutions. The tests performed on a real use case outline the robustness of 3D CAD tracking with respect to other solutions

Transient faults in computer-based systems for which high availability is a strict requirement, originated from several sources, like high energy particles, are a major issue. Fault injection is a commonly used method to evaluate the sensitivity of such systems. The paper presents an evaluation of the effects of faults in the memory containing the process descriptor of a Unix-based Operating System. In particular the state field has been taken into consideration as the main target, changing the current state value into another one that could be valid or invalid. An experimental analysis has been conducted on a large set of different tasks, belonging to the operating system itself. Results of tests show that the state field in the process descriptor represents a critical variable as far as dependability is considered.

Embedded and Computer-based systems are subject to transient errors originated from several sources, including the impact of high energy particles on sensitive areas of integrated circuits. The evaluation of the sensitivity of the applications to transient faults is a major issue. The paper presents a new approach for testing the effects of transient faults on the Operating System kernel, specifically focusing on kernel mutex data structure, a key component of the kernel. A Software-implemented Fault Injection tool able to inject faults guaranteeing the non-intrusiveness and repeatability of the fault injection campaign is proposed. An analysis of the results has been performed on a large set of mutexes, in order to evaluate their criticality, in particular during input/output operations. Experimental results, executed on a set of benchmarks programs, show the relevance of the effects of the transient faults on this set of variables. Moreover, a significant percentage of faults can lead to a damage of the system also producing an application failure

Graphics Processing Units (GPUs) have a huge number of cores to speed up graphical computations and they are being used in a wide area of general-purpose applications that require high performances. In this paper, GPU computing is exploited to model the signal propagation and the interference in large RFID systems, which are a promising solution for achieving pervasive computing since they offer the automatic object identification. The speedup of the parallel algorithm is evaluated with respect to a sequential version. Two popular frameworks for general-purpose computing on GPU are considered in the comparison, i.e. CUDA and OpenCL, and distinct implementations are provided for them, highlighting their differences in code optimization and performance

Motion capture systems provide an efficient and interactive solution for extracting information related to a human skeleton, which is often exploited to animate virtual characters. When the character can- not be assimilated to an anthropometric shape, the task to map mo- tion capture data onto the armature to be animated could be extremely challenging. This paper presents a novel methodology for the automatic mapping of a human skeleton onto virtual character armatures. By ex- tending the concept of graph similarity, joints and bones of the tracked human skeleton are mapped onto an arbitrary shaped armature. A pro- totype implementation has been developed by using the Microsoft Kinect as body tracking device. Preliminary results show that the proposed so- lution can already be used to animate truly different characters such as a Pixar-like lamp, a fish or a dog.

Big Data is today both an emerging research area and a real present and future demand. High Performance Computing (HPC) Centers cannot neglect this fact and have to be reshaped to fulfill this need. In this paper we share our experience of upgrading a HPC Center at Politecnico di Torino, originally designed and deployed in 2010. We believe that this issue could be common to some other existing \"general purpose\" HPC centers where, at least in the short term, the possibility to start from scratch a new Big Data HPC center cannot be afforded but a balanced upgrade of the existing system has to be preferred

After an era of \"personal-computers-only\", supercomputing facilities and services are coming back to Universities to support research activities and computationally intensive simulations, but with some important differences with respect to the past. Besides the technological issues, while in the seventies-eighties the scene was dominated by mainframes, managed by skilled system managers and most of times used by operators with good computer expertise, today, the widespread and pervasive use of computers has lead to a completely different scenario. The demand for computation resources is emerging from a wide variety of areas and disciplines and mostly by users with basic expertise in computers, who however most of times request to have full control of the computation resources. Within this picture and especially at University level, High Performance Computing (HPC) has emerged as a good tradeoff to meet the different demands, and at the same offering good services at reasonable setup and maintenance costs. Traditionally, HPC has been and is being mostly used in support to applied research, but more recently some questions have emerged: - How much is it reasonable to offer HPC also to some teaching activities? What are the problems, advantages, and drawbacks? Is this the \"right\" way or should HPC resources be directed to research only? At Politecnico di Torino we tried to respond to these questions and started a test project called HPC-4-teaching. In this paper we present the results achieved by this project on a small set of courses during one full academic year

This work describes the \"CSCT Living Lab\", where a new approach to learning, based on computational thinking and inquiry-based science, is practiced and shaped. Ten high schools, together with seven technical institutions and other three, chosen among vocational ones, have been involved. All these members, represented by teachers interested in joining the process, gave life to the lab, where enhanced scenarios for learning are planned, implemented and traced. An abstraction model is also proposed, to promote a collaborative learning context for teachers and students, derived from effective experiences carried out at University and Politecnico di Torino. A specific example, coming from process control domain, is described to show part of the scenario adopted to make inter-disciplinary learning a sustainable and effective experience

In this paper, a framework allowing to extend the applicability of natural user interaction techniques to existing programs is presented. Body gestures captured by a depth camera are mapped to application commands, and a wide set of common desktop applications can be controlled without any code rewriting

The Project PP&S100, Problem Posing & Solving, is part of a set of initiatives promoted by the General Directorate of the Italian Ministry of Education, Research and University, for supporting the many innovations that have recently affected curricula at the upper secondary level. Main goals of the project include strengthening computer science culture and enhancing its role as a scientific discipline; founding education processes on logics, mathematics and computer science weaved together to pursue an interdisciplinary scenario, building a culture of \"problem posing and solving\" by investing across a broad disciplinary group of subjects, ensuring growth of computer science based training of trainers and practicing activities within specific social networks and virtual learning environment to share learning materials, teaching supplies, mentoring and self-evaluation. This work presents a hierarchical conceptual model for \"Computational Thinking\" assumed by PP&S100, formalized according to the outcomes shown by information systems courses held at the Politecnico di Torino and validated using Process Control as an information system instance

Recently a new process to treat med-wastes close to the production sites has been settled-up. The process consists first in a smart collection of med-wastes at the hospitals. Then, med-wastes are grinded and sterilised in an apparatus called ma.ster.waste. The product of the ma.ster.waste, the so-called fluff (sterile and fluffy particles), possesses an average LHV of 25.3 MJ kg-1. Preliminary lab studies demonstrated the feasibility of transforming the fluff into a syngas with an average LHV of 15 MJ Nm- 3. The so-produced syngas can be directly fed to SOFC units, or it can be further transformed into hydrogen through specific CO clean-up processes for feeding PEMFC units for the production of clean energy

Our target was to improve mobility services within a large hospital center. We considered a modern hospital as case study. Our work had the valuable support of the San Raffaele Hospital (hSR). About patients and visitors' mobility we found vast room for improvement in terms of userorientation and support to disabled people. We analyzed people flows and service accessibility, to design an integrated mobility support service and generate the final solution. As smartphones provide a countless variety of communication channels, the challenge was the definition of an effective solution for people mobility exploiting these devices. After choosing a locationaware WLAN for tracking Wi-Fi devices, we defined the characteristics of the application for smartphones, and implemented a prototype. Many indexes, such as smartphone adoption growing rates, promising profitability studies, and massive portability of the mobile device indicate a smartphone application as an innovative and valuable support to improve mobility in hospital centers. © 2013 Springer-Verlag

Efficient sorting is vital for overall performance of the underlying application. This paper presents Butterfly Network Sort (BNS) for sorting large data sets. A minimal version of the algorithm Min-Max Butterfly is also shown for searching minimum and maximum values in data. Both algorithms are implemented on GPUs using OpenCL exploiting data parallelism model. Results obtained on different GPU architectures show better performance of butterfly sorting in terms of sorting time and rate. The comparison of butterfly sorting with other algorithms:bitonic, odd-even and rank sort show significant speedup improvements against all on Nvidia Quadro-6000 GPU with relatively better sorting time and rate

Color image acquisition in digital cameras is often performed by using CCD or CMOS sensor chips with a color filter array on the top of a single monochromatic sensor. In this paper, a perceptual comparison is per- formed among three well known demosaicing algorithms plus in-camera demosaicing with lossy compression JPEG, by means of subjective tests, that is with the help of human beings. The novelty of the approach is that chosen algorithms have been selected as representative of those used in commercial raw image converters used by professionals in graphics and that the test has been performed on a large number of people, achieving results only partially similar to the results got by means of computed metrics. The results show that in the greatest part of conditions and for non particularly expert users, the capability of the most advanced demosaic- ing algorithms of producing an almost perfect reconstruction on the full-color image is not strictly required. Only for selected categories of images it is possible to find a clear winner among the algorithms

Reader-to-reader interference significantly affects the performance of RFID applications. The design of an RFID system should carefully consider this phenomenon. Simulation can dramatically speed up the design and testing phase, by deferring the implementation of a prototype to the last phase of the development. Unfortunately, no specific simulators of interference in RFID networks are currently available. Previous works exploited either general purpose network simulators, which often do not provide the required features for simulating an RFID network, or self deployed tools, which are not publicly available and therefore do not allow the validation and reproducibility of the results. This paper identifies the requirements that a simulator of reader-to-reader interference should satisfy and presents the R2RIS simulator, which has been specifically designed to evaluate the performance of reader-to reader anti-collision protocols

Citizens' mobility and employability are receiving ever more attention by the European legislation. Various instruments have been defined to overcome lexical and semantic differences in the descriptions of qualifications, résumés and job profiles. However, the above differences still represent a significant constraint when abilities of non-European people have to be validated either for education and training or occupation purposes. In this work, a web platform that exploits semantic technologies to address such heterogeneity issues is presented. The platform allows migrants to annotate their knowledge, skills and competences in a shared format based on the European tools. The resulting knowledge base is then used to enable the automatic matchmaking of job seekers' abilities with companies' needs. The platform can additionally be used to support students and workers in the identification of their competence gap with respect to a given education or occupation opportunity, so that to personalize their further training

In recent years there has been an increasing effort in investigating integrated solutions to reduce energy consumption levels in different domains. In this perspective, tools thought as a support for the simulation and experimentation of energy saving strategies could constitute a valid help both in the design and validation phases. Within the above scenario, this paper presents a framework for monitoring, simulating and controlling energy-aware street lighting systems capable of optimizing their energy consumption levels based on environmental conditions and established lighting policies. The devised system allows operators to visually inspect (and control) the power saving impact of specific dimming rules in both monitored and simulated environments through the use of advanced 3D vision and interaction capabilities. In fact, a virtual interface is able to recreate the lighting effect within digital city environments, which can be explored by using immersive stereoscopic techniques. Moreover, natural user interfaces based on the recognition of user gestures and poses and voice commands are exploited to improve virtual navigation of the lighting infrastructures. By addressing all the presented aspects, the proposed system aims at constituting an effective tool to develop and analyze energy saving solutions in the domain of (but not necessarily limited to) future public street lighting.

In this work, the energy cost for 3D graphics processing on consumer devices is analyzed, and a framework mixing local and remote visualization techniques to trade off between rendering performances and power saving is proposed

The evolution of input device technologies led to identification of the natural user interface (NUI) as the clear evolution of the human-machine interaction, following the shift from command-line interfaces (CLI) to graphical user interfaces (GUI). The design of user interfaces requires a careful mapping of complex user \"actions\" in order to make the human-computer interaction (HCI) more intuitive, usable, and receptive to the user's needs: in other words, more user-friendly and, why not, fun. NUIs constitute a direct expression of mental concepts and the naturalness and variety of gestures, compared with traditional interaction paradigms, can offer unique opportunities also for new and attracting forms of human-machine interaction. In this paper, a kinect-based NUI is presented; in particular, the proposed NUI is used to control the Ar.Drone quadrotor

This paper presents a framework for controlling remote applications by means of personalized multi-touch interfaces. The designed framework allows end-users to fully personalize the mapping between gestures and input commands. A two-tier architecture has been developed. A formal description of the original interface is automatically generated at the server side to identify a set of available actions for controlling existing applications. The client is in charge of loading the description of the target application, allowing the user to shape the preferred mapping between gestures and actions. Finally, the server converts the identified actions into one or more commands understandable by the original computer interface. The implementation of the system for this work specifically relies on handheld multi-touch devices. Test results are encouraging, both from an objective and a subjective point of view; indeed, the designed framework resulted to outperform a traditional GUI both in terms of number of actions to perform a task and average completion time

Cloud computing is regarded to as an impressive technology, as software and hardware resources become invisible to the users (they \"fade\" in the cloud), and they replaced by services. In this sense, cloud computing can be considered as an evolution of former virtualization approaches, with service providers delivering on-demand access to various back-end frameworks and front-end applications. This approach requires to strongly trust these providers, as users are forced to give up control on programs and data that were previously hosted on their machines. A possible way to alleviate this drawback could be to enable users \"participate\" to the cloud with their own applications, thus creating \"personal\" clouds, which could be even shared with other users. In this paper, we present a prototype implementation of the above idea, which consists of a framework that allows today's applications to be put into the cloud by exploiting user interface automation and accessibility information embedded in modern window-based graphics toolkits

La mobilità di lavoratori e studenti rappresenta oggi un obiettivo di primaria importanza, in particolare nel contesto della istruzione e formazione professionale. Ciononostante, sebbene a livello Europeo siano stati sviluppati alcuni importanti strumenti a supporto della mobilità, esistono tuttora significative barriere che ostacolano la realizzazione di una concreto spazio comune del lavoro e dell'educazione. Una possibilità per superare le suddette limitazioni consiste nella creazione di profili professionali con validità trans-nazionale o trans-settoriale, che possano essere utilizzati dagli organismi di formazione e dagli attori di riferimento dei diversi settori economici per il raccordo tra qualifiche nazionali, regionali o settoriali. In questo lavoro viene illustrata una metodologia che sfrutta un approccio derivato da web semantico basato su ontologie e tassonomie per identificare un profilo comune Europeo nel settore del commercio e per raccordare singoli profili e qualifiche al Quadro Europeo delle Qualifiche a supporto della crescita di un mondo della formazione efficacemente connesso a quello del lavoro in una reale dimensione Europea

La realizzazione di reti per illuminazione stradale basate su tecnologie innovative e su soluzioni di monitoraggio e controllo intelligenti può indubbiamente contribuire ad una gestione più razionale ed efficiente delle risorse energetiche. In questo lavoro viene presentata una piattaforma software basata su soluzioni web e su tecniche di computer grafica e realtà virtuale progettata per la simulazione e la supervisione remota di infrastrutture pubbliche di illuminazione basate su punti luce a LED intelligenti in uno scenario di città digitale

The labor market is today characterized by a marked competitiveness. The ability to accurately choose the right education and training paths leading to the acquisition of the right competences required for a given job position, as well as the capability to properly select human resources based on precise job requirements are becoming more and more key factors to success. Nevertheless, the comparison of education opportunities generally requires a manual analysis of huge qualification descriptions and course syllabi, whereas staff selection (or job seeking activities) often relies on non-automated processes mainly based on an extensive check of applicants' curriculum vitae (or of possible job offers). The above tasks are extremely time consuming and, given the large amount of information to be considered, they also risk to provide unsatisfactory results. In this paper, the above issues are addressed in the perspective of semantic technologies. In particular, a webbased application is presented, which exploits ontological descriptions and tag cloud-based visualization strategies to generate a direct representation of the overlap between learners' needs and existing education and training paths, as well as between job seekers' profiles and company requirements. This way, potential users are provided with an effective support for matching job and study offers with corresponding demands

This paper presents a framework enabling 6-DOF interaction with generic visualization environments through mobile devices. Features computed on image frames captured by on-board camera are used to develop an affordable and effective 3D user interface

The application of computer graphics techniques to the creation of digital city environments is receiving increasing attention in the last years. This is in part due to the fact that, by mixing heterogeneous components like geographic information systems, virtual model repositories and smart sensor networks, digital cities are expected to be able to allow the various stakeholders involved in urban planning and management to effectively design, monitor and operate present as well as future city infrastructures. In this work, a software framework exploiting web and virtual reality technologies to remotely manage a network of LED-based smart luminaries is presented. The integration of public lighting systems into the digital city picture is considered of particular interest, since through these novel solutions, forthcoming intelligent lighting networks could be supervised in an integrated way, and specific safety, security and energy saving policies could be easily implemented

This paper describes a novel method to detect false alarms in target tracking applications based on image-based feature descriptors. The number of matches between the local feature descriptors in the reference target and in the candidate target is used to assess the reliability of the tracking algorithm used and, in case, to activate a suitable recovery mechanism. The proposed approach has been evaluated on a series of Forward Looking Infrared (FLIR) sequences provided by the U.S. Army Aviation and Missile Command (AMCOM)

A wide variety of remotely controlled mobile robots have been developed in the past. Despite the evolution in robotics functionalities, not much effort has been made to customize control interfaces to meet user preferences and needs. General users can find difficulties in controlling mobile robots by standard interfaces. On the other hand, recent advances in multi-touch devices now allow researchers to design and implement intuitive and user friendly interfaces. This paper presents recent efforts to control mobile platforms by using customizable multi-touch gestures drawn on a commonly available hand-held device. In particular, a live stream video coming from an on board camera allows both to automatically and manually control the platform to accomplish target tracking and following tasks

This paper presents a solution to control mobile robots by using customizable haptic and multi-touch gesture interfaces on handheld devices. Images coming from a camera allows both to automatically and manually control the robot

Wireless Sensor Networks (WSNs) are used in an increasing number of applications in different fields, from agricultural monitoring to energy-saving systems for buildings. The development of WSNs has been always constrained by the power consumption of nodes that constitute the network since they should be as much autonomous as possible and human intervention must be reduced to the minimum. Several algorithms and protocols have been designed with the goal of reducing power consumption. Related works take into consideration Media Access Control (MAC) protocols that keep sensors' power consumption low at that layer. Nevertheless, these protocols require some parameters, e.g. duty cycle, to be configured according to network characteristics in order to achieve an acceptable level of efficiency. In this work, we propose a Fuzzy Logic Controller (FLC) which adapts the MAC protocol parameters by employing local node inputs such as battery power and average packet traffic. We present the FLC design and perform simulations that show its feasibility. We evaluate the FLC in terms of its power savings capabilities and show that for high-traffic and low-energy nodes power consumption may be reduced up to 50%

Sorting algorithms have been studied extensively since past three decades. Their uses are found in many applications including real-time systems, operating systems, and discrete event simulations. In most cases, the efficiency of an application itself depends on usage of a sorting algorithm. Lately, the usage of graphic cards for general purpose computing has again revisited sorting algorithms. In this paper we extended our previous work regarding parallel sorting algorithms on GPU, and are presenting an analysis of parallel and sequential bitonic, odd-even and rank-sort algorithms on different GPU and CPU architectures. Their performance for various queue sizes is measured with respect to sorting time and rate and also the speed up of bitonic sort over odd-even sorting algorithms is shown on different GPUs and CPU. The algorithms have been written to exploit task parallelism model as available on multi-core GPUs using the OpenCL specification. Our findings report minimum of 19x speed-up of bitonic sort against odd-even sorting technique for small queue sizes on CPU and maximum of 2300x speed-up for very large queue sizes on Nvidia Quadro 6000 GPU architecture

The energy and computational constraints of Wireless Sensor Networks (WSN) have motivated the exploration of efficient routing algorithms. In this paper, a new routing approach is presented which attains the best trade-off between energy expenditure and hop-distance to the sink. The routing algorithm exploits a low-computation metric based on the node's remaining battery. Routing is performed by means of a modified Dijkstra's algorithm which calculates the node's position in the routing tree while computes the least-cost path of all nodes towards the sink. Simulations were performed for different network densities demonstrating that the proposed algorithm enhances the overall energy conservation of the network while efficiently routing data traffic

Students and workers mobility in the European scenario represents today a big challenge. During the last years, several initiatives have been carried out to deal with the above picture, being the European Qualication Framework (EQF), a common architecture for describing qualications, one of the most signicant. In parallel, several research activities were established with the aim of exploiting semantic technologies for qualication comparison in the context of human resources acquisition. In this paper, the EQF specications are applied in a practical scenario to develop a ranking algorithm allowing for qualication comparison on the basis of knowledge, skill and competence concepts, potentially aimed at supporting European employers during the recruitment phases

Wireless communication advances enable emerging video streaming applications to mobile handheld devices. For example, it is possible to show and interact with a complex 3D virtual environment on a \"thin\" mobile device through remote rendering techniques, where a rendering server is in charge to render 3D data and stream the corresponding image flow to the demanding client. However, due to bandwidth fluctuating characteristics and limited mobile device CPU capabilities, it is extremely challenging to design effective systems for interactive streaming multimedia over wireless networks. This paper presents a novel approach based on a controller able to automatically adjust streaming parameters basing on feedback measures coming back from the client device. Experimental results prove the effectiveness of the proposed solution to cope with bandwidth changes, thus providing a high Quality of Service (QoS) in remote visualizations.

IEEE, 6th International Conference on Emerging Technologies, Oct, 2010

Automatic segmentation of the breast and axillary region is an important preprocessing step for automatic lesion detection in breast MR and dynamic contrast-enhanced-MR studies. In this paper, we present a fully automatic procedure based on the detection of the upper border of the pectoral muscle. Compared with previous methods based on thresholding, this method is more robust to noise and field inhomogeneities. The method was quantitatively evaluated on 31 cases acquired from two centers by comparing the results with a manual segmentation. Results indicate good overall agreement within the reference segmentation (overlap=0.79±0.09, recall=0.95± 0.02, precision=0.82 ± 0.1).

Students' mobility is a relevant topic but, while in Higher Education transfers between Universities are a praxis, in Vocational Educational and Training are still a declaration of intent. The main obstacles are basically related to the heterogeneity of national qualification systems, and to the lack for definitive transparency measures. Although several European instruments are being introduced in this perspective (like the European Qualification Framework), the internationalization process is still in a preliminary phase. In this paper, a methodology exploiting formal descriptions for supporting the creation of mutual understanding and for defining transnational referencing rules is defined. Rules, developed by actors involved in VET provision, are then applied to a knowledge base hosting annotated national qualifications to experiment qualification comparison and to measure competence gap

Variable preamble sampling is a technique used for accessing the medium in low-power constrained networks such as wireless sensor networks. We provide an optimal bound for power consumption in preamble sampling techniques, and we present a model of this technique as a function of power consumption and time of radio utilization. We compare our model by means of experimental experiences performed with commercially-available hardware. Our model shows the tendency of the network for constant and variable preamble sampling approaches and may be used to analyze large networks without actually deploying them

This work presents the methodology used to leverage ontologies for the vocational education & training (VET) domain under an European context.The ontology use provides a means to tackle the problem of information integration of the qualification systems on each country, allowing a common data access. The project involved qualification systems at post-secondary non-academic level of diverse EU countries, formalizing their profiles, activities, competences, learning outcomes, etc. In particular, the Dutch system is used as study case

In this paper an agri-food traceability system based on public key cryptography and Radio Frequency Identification (RFID) technology is proposed. In order to guarantee safety in food, an efficient tracking and tracing system is required. RFID devices allow recording all useful information for traceability directly on the commodity. The security issues are discussed and two different methods based on public cryptography are proposed and evaluated. The first algorithm uses a nested RSA based structure to improve security, while the second also provides authenticity of data. An experimental analysis demonstrated that the proposed system is well suitable on PDAs too

The present work describes the work carried out in the EU LdV HELeN Projec regarding the use of web ontologies as a way to tackle the qualification systems? integration for enabling transparency and mobility of students at European level. Qualification systems at post-secondary non-academic level of nine EU countries have been formalized in terms of profile, activities, competences, learning outcomes, etc. first using UML for a human-readable model and then using OWL for a machine-processable one. In addition, concrete qualification profiles have been used as study case to validate the ontology correctness

RFID technology increases rapidly its applicability in new areas of interest without guaranteeing security and privacy issues. This paper presents a new architecture of an RFID transponder with cryptographic capabilities. Other than being compatible with the EPC Class-1 Gen-2 communication protocol, our tag implements an asymmetric ciphering module that proved useful in authentication and anti-counterfeit schemes, particularly critical in many application fields. Experimental results concerning area requirements and power consumption indicate its feasibility

In this paper we analyzed classical forward error correction (FEC) algorithms implemented in wireless sensor networks (WSNs). We adopted FEC algorithms in sensor network nodes and evaluated performance and cost related to their covered area. Experimental results show how FEC adoption increases bit error tolerance in additive white Gaussian noise channels while rising computational costs in an acceptable fashion; coding gains reach values higher than 1 dB with a time latency that is negligible when compared with WSN data rates

This work presents the use of ontologies as a way to tackle the problem of integration of qualification systems in order to enable the transparency and mobility of students at European level. For this, qualification systems at post-secondary non-academic levels of nine EU countries have been formalized in terms of profile, activities, competences, learning outcomes, etc., first using UML for a human-readable model and then using OWL for a machine-processable one. In addition, concrete qualification profiles have been used as a case study to check the models' correctness

This paper investigates the problem of tracking individual circular cell nuclei of endothelial cells during their migration. The purpose is to extract statistical information to support research activities devoted to reaching a better understanding of the underlying biological phenomena. This goal is achieved by exploiting a general tracking framework based on a multiframe point correspondence approach and capable of translating the matching problem into a maximum path cover problem over a graph based representation of moving objects. The application to phase contrast microscopy images containing hundreds of cells aggregating to form capillary tubes required to design an ad-hoc weight function capable of properly handling cells occlusion and aggregation.

Vascularization is defined as the sprouting of new blood vessels by expansion of the endothelium by proliferation, migration and remodeling. Vascularization is fundamental to healing, reproduction as well as embryonic development. It also plays a key role in tumor growth, tumor metastasis and other pathological processes. Understanding biological phenomena driving the creation of vascular structures is therefore essential for clinical treatment of cancer and other vascularization-related diseases. Recently, an analytical model capable of mimicking the process of in-vitro vascular network creation from randomly seeded endothelial cells has also been proposed. This paper presents the development of a novel neural network based segmentation technique working on phase contrast microscopy snap photographs of cultured endothelial cells which allows for cell structures geometry quantitative analysis thus constituting a key instrument in the development of computerized tools for vascularization parameters measurement as well as supporting also analytical model deployment and validation.

This paper presents a comprehensive framework for quantitative analysis of vascular processes from in-vitro videomicroscopy data. By following an active contours based approach, we designed a quasi-automatic technique enabling highly interacting motile endothelial cells (ECs) tracking in large field of view phase contrast microscopy video sequences. Our work was motivated by the necessity of validating through statistical analysis an analytical model mimicking ECs behavior. However, the proposed framework could also constitute an invaluable tool supporting general experimental studies on vascularization. Our tracking technique has been extensively validated on realistic data-sets by comparison with a manually defined ground-truth.

The design of accurate in silico cancer models capable of quantitatively predicting tumor growth is an important goal in cancer research today. Mesoscopic models have shown great promise in this scenario; however, their use is often inhibited by the difficulty in correctly assigning parameter values. In this paper, enabled by an extremely computationally efficient mesoscopic model, we propose a Genetic Algorithms' (GAs) approach to the exploration of parameter space. Analysis of the results suggest that this novel application of GAs to tumor growth models both facilitates the attribution of parameter values to the fitting of experimental data and, more importantly, lends insight to the role played by the different parameters in regulating the tumor model growth.

Demand-responsive transport services are systems that assign users ' specific transport requests to different vehicles enabled to fulfill the required service. In order to contain costs, maximize profits or get a higher service level, different planning algorithms have been described in literature. In our work we propose a multi-agent architecture, which adopts a mixed planning model. This model is an integration of centralized and negotiation based decision-making approaches. The advantage of using this model respect to a centralized approach is that the estimation of the uti1ir) function is avoided (the client is involved in the final decision by means of a negotiation process). The model advantages a complete decentralized approach in giving results that are not so far from the optimum for the whole system.

Vasculogenesis is defined as the sprouting of new blood vessels by expansion of the endothelium by proliferation, migration and remodeling. Vasculogenesis is fundamental to wound healing, reproduction as well as embryonic development. Moreover, it is involved in tumor growth, tumor metastasis and other pathological processes. The availability of dedicated image-based analysis systems would constitute an invaluable support in understanding biological phenomena regulating vasculogenesis processes. In this paper we present an unsupervised segmentation technique which allows for accurate classification of blood vessel networks in in-vitro microscopy images. Results achieved through the proposed technique are validated and compared with experimental observations.

Computationally intensive applications often require the employment of parallel/distributed solutions in order to strongly reduce execution times. Workstations and PCs connected by a fast local network provide effective, low-cost, and general purpose solutions that are quickly replacing special purpose proprietary architectures for a wide spectrum of disciplines. The issue to monitor the performance (fundamental to check the efficiency of a distributed application) of cluster architectures is addressed in this work. This paper presents a multi-channel architecture for remote monitoring-management tailored to display information on PDA devices. Users can remotely monitor the system critical activities and cluster resources utilization; moreover, we provide the possibility to perform some management tasks (for instance, shutdown and reboot) useful for maintaining the integrity of the system and to harness the full cluster potential.

In this paper the design and development of a low-cost homecare architecture for remote patient telemetry built upon a Java-based embedded computer is presented. The proposed architecture has been validated by experiencing real-time ECG monitoring by means of desktop PCs equipped with Web browsers, Personal Digital Assistants and WAP-enabled GSM/GPRS mobile phones. The modular approach followed in the development of the home station allows additional medical devices to be easily integrated to fulfil the requirements of heterogeneous homecare scenarios. We expect that the availability of such a low-cost telemedicine device will contribute to further extend healthcare reach to the homecare environment.

A novel neural network-based technique for segmentation of single-channel magnetic resonance images is presented. The segmentation of single-channel magnetic resonance images is a daunting task due to the relatively little information available at each pixel site. The proposed algorithm is based on unsupervised clustering by means of a Kohonen Self-Organizing Map: unsupervised segmentation algorithms are highly desirable in order to eliminate intra- and interobserver variability. Particular attention has been devoted to the choice of suitable features, in order to ensure an accurate and reliable segmentation: in particular, a feature set extracted from the neighborhood of each pixel has been evaluated. The proposed technique has been tested on simulated magnetic resonance images to assess its stability against the presence of noise and intensity inhomogeneities. Moreover, it has been tested on real magnetic resonance images of both volunteers and brain tumor patients. The preliminary results presented make the proposed technique a promising alternative for the segmentation of single-channel magnetic resonance images and encourage further investigation.

A new category of devices, known as Personal Digital Assistant (PDA), has become increasingly widespread since the end of the nineties. A large number of software applications have been developed for PDAs, but high-quality 3D graphics still remain beyond the computational capability of these devices.This paper tackles this issue by proposing a generic solution for hardware-accelerated remote rendering on cluster. The rendering task is submitted to a PC/workstation cluster (each cluster machine is equipped by a graphics accelerator) by means of the Chromium architecture. Each machine renders a part of the image that is then reassembled and sent to the PDA via a software bridge. On the PDA side, the user can explore the scene using an ad-hoc navigation interface.The proposed solution allows to display extremely realistic and complex models in an interactive way. Moreover, our architecture does not depend on commercial solutions/products and can be easily modified in order to better fulfill requirements of specific applications

The presence of different kinds of artifacts has long been a problem in the analysis and interpretation of electroencephalographic recordings. Recently blind source separation by Independent Component Analysis (ICA) has been successfully employed for the detection and removal of artifactual components and new methods for the automatic identification of the artifactual components are being proposed. In this paper we focus on the automatic removal of eyeblink components from EEG data. First a model of the topographic maps associated to the ICA eyeblink component and a distance quantifying the resemblance to the model are defined. To further improve the reliability of the system, an eyeblink detector was designed which locates the individual eyeblinks within the component, thus confirming the nature of the activation.

This paper presents the preliminary results in the development of a framework for ubiquitous monitoring in a Intensive Care Unit environment, which aims at enabling mobile access to real-time bedside monitoring data and to a comprehensive electronic patient's clinical record at any moment in time and from any location, by means of a PDA device capable of secure wireless communications. The main goal of the proposed architecture is to optimise the employment of human resources involved in monitoring activities, while at the same time enhancing the quality of delivered services and improving the level of attention to patients.

Several algorithms can effectively represent vector fields by texture-based representations, visualizing at most all information on the field: direction, orientation, and local magnitude. An open problem still remains the mapping on textures of adjunctive information such as temperature, pressure, and so on, without using colors. This article addresses this issue by proposing a technique to add a scalar value denoting streamlines by means of different levels of contrast. Both streamline starting tones and the range of tones depend on the scalar value to be mapped; in this way, areas visualized by different contrast levels are represented. Two examples show the effectiveness of the proposed technique

In this paper, a mobile teleconsultation system based on the use of a PDA is presented. The proposed architecture has been evaluated both over a low bandwidth GPRS public network well-suited for remote emergency diagnosis and in a broad-band WLAN IEEE 802.11 environment suitable for in-hospital care management. The simulation studies with radiological images and ECG signals shows the effectiveness of such a solution in both an interactive and an off-line scenario

In this paper, a mobile teleconsultation system based on the use of a PDA is presented. The proposed architecture has been evaluated both over a low bandwidth GPRS public network well-suited for remote emergency diagnosis and in a broad-band WLAN IEEE 802.11 environment suitable for in-hospital care management. The simulation studies with radiological images and ECG signals shows the effectiveness of such a solution in both an interactive and an off-line scenario.

In this paper a PVM-based distributed platform of the well known REYES rendering architecture developed byPix ar is presented. This work effectivelyt ackles issues related to load balancing and memory allocation by a master-slave paradigm. In particular, the rendering is distributed performing both an image and an object space subdivision; in this way, low memory resources are necessary to the slave side. Examples show the effectiveness of the proposed work.

Standardization is a key issue in the field of biosignals acquisition and storage. By easing the interoperability between medical devices and telemedical information systems, it facilitates telemedicine system design and health care center collaboration, thus enhancing the quality of delivered sanitary assistance. While in the field of medical imaging the DICOM standard has gained widespread acceptance, in the field of biomedical signals acquisition and storage many alternatives still exist. In this paper, we investigate the feasibility and validity of the implementation of an integrated, patient-based clinical database compliant with the CEN/TC251 Vital Sign Information Representation (VITAL) ENV standard. Both the conceptual model and the implementation of the clinical database are presented. To validate the applicability and the performance of the proposed solution, the designed database has been tested into an advanced telemedicine platform addressing crucial healthcare scenarios

This paper presents an advanced telemedicine architecture enabling mobile teleconsulting and telediagnosis applications in the medical imaging domain. The feasibility of a portable teleradiology unit based on a Personal Digital Assistant (PDA) and providing medical experts with wireless connectivity over the General Packet Radio Service (GPRS) of the GSM telecommunication network has been experienced by extending to mobile users the interactive services currently provided by an existing regional network for radiological teleconsulting devoted to mild head injury case management. Moreover, the effectiveness of synchronous cooperative work applications including voice conferencing and medical data sharing in a mobile environment has been evaluated. By ensuring skilled medical staff availability wherever and wherever needed still providing the same capabilities of traditional telemedicine systems over broadband networks, the proposed architecture will contribute to increase the quality of remote health care delivery

In recent years, virtual reality has shown all its potential in a large spectrum of applications: training, simulation, CAD, and so on. Although existing technologies allow the creation of immersive virtual reality browsing experiences, little has been devoted to applying this new tool to electronic commerce (e-commerce) since almost all e-commerce web sites present products in a 2D on-line catalog. In this paper we present 3D-dvshop, a dynamic 3D virtual shop: a user can build his or her own shop, choosing a set of products that will be dynamically placed in a collection of specially created \"rooms\". The use of technologies such as VRML and Java allows full 3D interaction with products. In this way, the browsing experience can be more natural, attractive, realistic, and fun

Visualization of vector data produced from application areas such as computational fluid dynamics (CFD), environmental sciences, and material engineering is a challenging task. Texture-based methods reveal to be e ective, versatile, and suitable for a large spectrum of applications since they allow to obtain high resolution output textures where direction, orientation, and magnitude of the ow can be displayed. In this paper we present a new method called B 2 LIC, which allows both to characterize and visualize interesting structures in the ow and to map two additional scalar values in output textures by bumps, depressions, and shadows, leaving colors for further information mapping. B 2 LIC is the natural and direct evolution and the improvement of the BLIC (Bumped LIC) algorithm, which is able to map just one scalar value by the bump mapping technique. Some examples show how the proposed method can e ectively allow to map two additional scalar values such as: temperature, vorticity, pressure, and so on, adding new and additional representation capabilities to dense texture-based visualization methodologies.

An extension of the very-high radix division with prescaling and selection by rounding is presented. This extension consists in increasing the effective radix of the implementation by obtaining a few additional bits of the quotient per iteration, without increasing the complexity of the unit to obtain the prescaling factor nor the delay of an iteration. As a consequence, for some values of the effective radix, it permits an implementation with a smaller area and the same execution time than the original scheme. Estimations are given for 54-bit and 114-bit quotients.

The SPIN extension presented in this article is meant as a way to facilitate the modeling and verification of object-oriented programs. It provides means for the formal representation of some run-time mechanisms intensively used in OO software, such as dynamic object creation and deletion, virtual function calls, etc. This article presents a number of language extensions along with their implementation in SPIN. We carried out a number of experiments and found out that an important expressibility gain can be achieved with at most a small loss of performance.

The Java language enables the development of concurrent and distributed software through the concepts of thread and remote method invocation (RMI). It is known that developing concurrent and distributed software is a challenging task, mainly because of potential concurrency errors such as deadlocks and livelocks. One promising way to help the designer bl this task is providing static analysis tools that can detect such errors in the source code, as documented in the rich literature on static analysis of Ada tasking programs. This paper extends the approach followed for Ada tasking programs to the new Java language, providing formal models for the main thread synchronization primitives offered by the language. The formalism used is Promela, the input language of the model checker SPIN, which is based on extended communicating finite state machines and provides an efficient analysis algorithm

We present a new and efficient algorithm to generate rendered animation. With respect to the approaches known in the existing literature, our algorithm does not generate the animated sequences frame-by-frame, but it renders only the parts which change between two following frames by exploiting the frame-to-frame coherence. We show, with practical examples, the efficiency of the proposed technique. In the proposed examples the animation can be rendered, with our method, at least eight times faster than by using a straightforward frame-by-frame technique

An algorithm for square root with prescaling is developed and combined with a similar scheme for division. An implementation is described, evaluated and compared with other combined div/sqrt implementations

A division algorithm in which the quotient-digit selection is performed by rounding the shifted residual in carry-save form is presented. To allow the use of this simple function, the divisor (and dividend) is prescaled to a range close to one. The implementation presented results in a fast iteration because of the use of carry-save forms and suitable recodings. The execution time is calculated, and several convenient values of the radix are selected. Comparison with other high-radix dividers is performed using the same assumptions

The authors consider the possibility of designing architectures which combine in the best possible way the convergence with the square advantages of the Newton-Raphson method with the precision characteristics of the digit-by-digit algorithms so as to obtain units which satisfy the IEEE 754 floating point standard requirements. This is a general method which can be extended with simple and minor changes also to square root. Attention is focused on a possible implementation of this design methodology for division. The evaluation shows that the proposed unit offers an alternative architecture for division which provides interesting performances

A study of the throughput and time characteristics of double-ring networks is presented, assuming that the two channels are used for balancing the traffic (when both are working) and for synchronous traffic generated according to a generic but periodic pattern. In addition, reconfiguration using portions of both rings to circumvent faulty elements in a double ring network is shown to be equivalent to the single ring configuration already studied. Examples of applications of the results are also illustrated

A general approach is outlined for designing units for higher radix division, which are based on two subunits operating in parallel. A lower radix division unit is used as the building block of the architecture, and the division step is split into two phases which are carried out in parallel. It is shown that the proposed architecture permits the design of units for higher radix division with digit selection tables requiring few supplementary input bits compared to the tables used by lower radix division systems

Technical Report

Technical Report

La Stampa, tutto Scienza e tecnologia

International Journal of Mini and Microcomputers

International Journal of Mini and Microcomputers