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Bruno Andò, Salvatore Baglio, Cristian Orazio Lombardo, Vincenzo Marletta
User Tracking for AAL: an inertial approach

This paper deals with a novel multi-sensor approach for the implementation of a tracking system exploiting features of smartphones. Actually, the widespread use of smartphones and performances provided by the variety of sensors embedded in these devices encourage their use in mobility oriented applications, such as the exploitation of educational/job environments by weak people. The proposed methodology exploits information provided by the multisensory features embedded in a standard smartphone and advanced paradigms to improve the efficiency of the system in performing user tracking tasks.

Paolo Bifulco, Maria Romano, Mario Cesarelli, Luigi Iuppariello, Nicola Pasquino
Estimation of quantum noise in fluoroscopy by analyzing differences of static images

Quantum noise is typical of images obtained with a small amount of photons and X-ray fluoroscopy is an example of the type. Indeed, to keep the doses of radiation to acceptable levels for the patient and, at the same time, to allow prolonged screening, the number of X photons is drastically reduced giving rise to a remarkable quantum noise on the images. For various applications it is necessary to estimate the level of this noise: this study proposes to use a limited number of fluoroscopic images depicting a static scene to estimate the noise. By considering the noise samples uncorrelated (e.g. for a single pixel) and computing all possible differences due to the number of images, it is possible to estimate fairly accurately the characteristics of the noise (and the gain of the sensor). Statistically, quantum noise is Poisson distributed, while the difference of two Poissonians gives a Skellam distribution. Making a difference between two static images will automatically result in cancellation of the image (the scene), whatever it is, highlighting only the noise. Using only few images it is possible to provide an estimation of noise, which is comparable (only slightly less accurate) to that should be obtained from an analysis performed with much more images.

Paolo Bifulco, Gaetano Gargiulo, Giovanni d’Angelo, Annalisa Liccardo, Maria Romano, Fabrizio Clemente, Mario Cesarelli
Monitoring of respiration, seismocardiogram and heart sounds by a PVDF piezo film sensor

In-vivo monitoring of patient’s cardiac mechanics via seismocardiogram was recently introduced (demonstrated). Usually, seismocardiogram is recorded using accelerometers placed on patient’s sternum. This study present the ability of a PVDF piezo film transducer to record the mechanical activity of the heart (seismocardiogram and heart sounds) and also of the respiration-related, thorax motion. The transducer was positioned on patient’s sternum and held in position by a chest strap. Patient’s ECG signal was simultaneously recorded to provide a timereference of the cardiac activity. The piezoelectric sensor was able to record respiratory movements, seismocardiogram and heart sounds: these signals can be obtained from the recorded signal by applying simple filters. The seismocardiogram waveform appears to be dependent on the various phases of the respiratory cycle. The recorded signal from the sole piezoelectric sensor can provide relevant information such heart rate, respiratory rate, timing of mechanical event within the cardiac cycle, etc.

Paolo Bifulco, Attilio Marrese, Nicola Pasquino, Rosario Schiano Lo Moriello
Statistical Characterization of Human Exposure to GSM Electromagnetic Field

Statistical characterization of the maximum power received in the GSM band is presented. Results show a large unexpected variability of BCCH channel power over time. Such evidence results in a large uncertainty related to the measurement of the average power through use of the α24 parameter as required by the Italian standards to assess average exposure to electromagnetic fields and compliance with limits.

Fanel Iacobescu, Alexandru Salceanu, Mirela-Adelaida Anghel, Albert-Ciprian Anghel
Monitoring and Controlling the Air Quality- Environmental Pollutants. Evaluation of Uncertainty Budget

Accurate and reliable air polluttants measurements are widely required all over the world. Measurement science is something of vital importance to all of us. The monitored polluttants, the measurement methods, the limit values, the laert thresholds nd the criteria for locating and monitoring points have been established by national legislation on the protection of the atmoshere and meet the requirements stipulated by EU regulations. The paper presents the colclusions which have been drawn using statistical inference tools, based on the data collected during measurements of few air polluttants CO, SO2, NOx. Measurements were collected for a period of 3 months, 10 days/month, using gas analyzers configures with NDIR (Non-Dispersive Infrared Absorbtion) sensors. Additionally, basd on experience, the paper describes, step by step, an example of uncertainty budget evaluation of SO2 for measuring air polluttants.

Valeria Serchi, Agnese Peruzzi, Andrea Cereatti, Ugo Della Croce
Performance of a remote eye-tracker in measuring gaze during walking

Combining virtual environments and eyetracking can provide insights about the relationship between gaze and gait in people at high risk of fall. Remote eye-trackers can estimate gaze while the head moves within a limited workspace, but several factors can influence accuracy and precision. This study aimed at assessing the performance of a remote eyetracker both during controlled head movements and walking on a treadmill, while the visual stimulus moved on the screen. The head range of motion during gaze estimation was determined. The distance from the eye-tracker influenced data accuracy and precision of gaze estimation, while the target location was not a critical factor. The best accuracy was achieved at 650 mm from the eye-tracker (11±3 mm) and, during walking. Gaze fixations hitting static and moving objects were counted during standing (87 to 93 %) and walking (85 to 98 %), providing promising results for applications in virtual environments.

Diana Trojaniello, Andrea Cereatti, Alan K Bourke, Kamiar Aminian, Ugo Della Croce
A wearable system for the measurement of the inter-foot distance during gait

Inter-foot distance (IFD) is an important indicator of gait stability. The IFD evaluation in outdoor conditions is still an open issue. The aim of this work was to develop and evaluate a wearable system integrating an infrared range sensor (IRR) and an inertial measurement unit (IMU), for the IFD estimation during mid-stance and mid-swing. First, the IRR sensor output was characterized and calibrated. Second, precision and accuracy were assessed in static conditions using a target object. Third, data were acquired on a subject during various lower limb movements and compared to a gold standard to evaluate the IRR-IMU dynamic performance. Mean error during the IRR accuracy tests revealed a mean error of 2.7 mm. During walking the error was about 5 mm (up to 10 mm for gait with wide steps). In conclusion, the tests performed seems to support the feasibility of the IRRIMU use for the estimation of the IFD during specific gait phases.

Andrea Castelli, Gabriele Paolini, Andrea Cereatti, Ugo Della Croce
2D video-based human gait analysis: a novel markerless approach

A 2-D markerless technique for the analysis of the lower limbs kinematics during gait is presented and preliminarily validated. Data were recorded using a single video camera placed laterally to the walkway. The preliminary validation was performed using a optoelectronic marker based system as gold standard. The lower limb facing the camera was modelled with four body segments: foot, shank, thigh and pelvis. Ankle socks and underwear garments were used as segmental markers to track the foot and the pelvis, respectively. The shank and thigh were tracked using multiple reference points defined in a calibration reference image. The comparison between the estimated segment angular kinematics and that obtained with the gold standard revealed a high correlation index and limited Root Mean Square Deviation (RMSD) values. The proposed technique can be considered as an easy-to-configure and affordable alternative to marker-based systems, for 2D human lower limb motion tracking during gait.

Roman Zdzislaw Morawski, Yevhen Yashchyshyn, Rafał Brzyski, Frode Fadnes Jacobsen, Wiesław Winiecki
On applicability of impulse-radar sensors for monitoring of human movements

The importance of research on new technologies that could be employed in care services for elderly and disabled people is highlighted. The need to examine the applicability of various sensor systems for non-invasive monitoring of the movements and vital bodily functions, such as heart beat or breathing rhythm, of persons in their home environment is justified. An extensive overview of the literature, concerning existing monitoring techniques, is provided. A technological potential behind impulseradar sensors is indicated. New systemic and algorithmic solutions are proposed. Preliminary results of its investigation are presented.

Alessandro Murgia, Marco Ortu, Roberto Tonelli, Giulio Concas, Michele Marchesi, Steve Counsell
Measurements to assess the effort related to different kinds of software maintenance

The Issue Tracking System is a repository used to support the software development activity. Differently from Bug Tracking Systems, the Issue Tracking Systems are not bug-centric. Indeed, they record entries related to corrective, adaptive and perfective maintenance. This study tackles in the under-explored aspect of software maintenance related to the resolution of the issue-types new feature, task and improvement. We mine the issue tracking systems of five open source projects with more than 9000 issues, discovering that maintenance effort and priority are influenced by the issue-type handled.

Page 449 of 977 Results 4481 - 4490 of 9762