1,009 research outputs found
Data Compression for Digital Photography: Performance comparison between proprietary solutions and standards
No full textA Social Internet of Things Smart City Solution for Traffic and Pollution Monitoring in Cagliari
No full textIn the last years, the smart city paradigm has been deeply studied to support sustainable mobility and to improve human living conditions. In this context, a new smart city based on Social Internet of Things paradigm is presented in this article. Starting from the tracking of all vehicles (that is, private and public) and pedestrians, integrated with air quality measurements (that is, in real time by mobile and fixed sensors), the system aims to improve the viability of the city, both for pedestrian and vehicular users. A monitoring network based on sensors and devices hosted on board in local public transport allows real time monitoring of the most sensitive areas both from traffic congestion and from an environmental point of view. The proposed solution is equipped with an appropriate intelligence that takes into account instantaneous speed, type of traffic, and instantaneous pollution data, allowing to evaluate the congestion and pollution condition in a specific moment. Moreover, specific tools support the decisions of public administration facilitating the identification of the most appropriate actions for the implementation of effective policies relating to mobility. All collected data are elaborated in real time to improve traffic viability suggesting new directions and information to citizens to better organize how to live in the city
DMR networks for health emergency management: A case study
No full textThis paper illustrates the Digital Mobile Radio (DMR) technology for mission critical applications, and evaluates its performance against other professional mobile radio (PMR) standards, with a special focus on TETRA. We also describe the design of a practical DMR network, i.e. the radio system for the health emergency service in Sardinia (Italy), and we illustrate the advantages of migrating from analog to digital technology. Finally, we discuss the capabilities of DMR technology to provide the best solution for a wide regional emergency network with cost saving constraints
An association-based graphical password design resistant to shoulder-surfing attack
No full text10.1109/ICME.2005.1521406IEEE International Conference on Multimedia and Expo, ICME 20052005245-24
The turbulent dissipation rate from PIV measurements
No full textThe result of a particle-image velocimetry (PIV) measurement is a velocity field averaged over interrogation windows. This severely affects the measurement of small-scale turbulence quantities when the interrogation window size is much larger than the smallest length scale in turbulence. A direct measurement of the dissipation rate demands the measurement of gradients of the velocity field, which are now underestimated because the small-scale motion is not resolved. A popular procedure is to relate the statistical properties of the measured, but underresolved gradients to those of the true ones, invoking a large-eddy argument [3]. We show that the used proportionality constant, the Smagorinsky constant, should depend on the window overlap, on the used elements of the strain tensor, and on the way in which derivatives are approximate
Using user's position to improve video multicast subgrouping in 5G NR
No full textThis paper addresses the use of machine learning techniques for the determination of subgroups within 5G networks. Currently, the burden of determining the subgroups falls uniquely on the gNB. The aim of this work is to lighten the computation burden of the gNB in estimating the evaluation of the position and mobility of users, with the ultimate aim of determining the optimal modulation and coding scheme (MCS). This work proposes an innovative approach based on machine learning techniques that are interposed among user and gNB, helping the latter to determine the network configuration. The results obtained show how direct communication between UEs and neural network speeds up the determination of the MCS and the allocation of resources to subgroups within 5G technology
How the dispersion of a droplet cloud depends on its initial size
No full textA cloud of droplets evolves under the influence of strong turbulence. The droplets are made from a phosphorescent fluid. From this cloud we select at t = 0 a narrow line by exciting the droplets with a UV laser, which causes them to glow for a few milliseconds. The dispersion of this line is followed in time using a fast intensified camera. A large range of droplet sizes (Stokes number St) was measured. It appears that lines with St \approx 1 disperse faster than a line of fluid tracers. Lines of droplets which are narrowest initially, spread fastest
Tackling the sheer scale of subjective QoE
No full textMaximum Likelihood Difference Scaling (MLDS) used as a method for subjective assessment of video quality alleviates the inconveniencies associated with high variation and biases common in rating methods. However, the number of tests in a MLDS study rises fairly quickly with the number of samples that we want to test. This makes the MLDS studies not scalable for the diverse video delivery environments commonly met in pervasive media networks. To tackle this issue we have developed an active learning approach that decreases the number of MLDS tests and improves the scalability of this method
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