210 research outputs found

    Sleep Period Optimization Model For Layered Video Service Delivery Over eMBMS Networks

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    Long Term Evolution-Advanced (LTE-A) and the evolved Multimedia Broadcast Multicast System (eMBMS) are the most promising technologies for the delivery of highly bandwidth demanding applications. In this paper we propose a green resource allocation strategy for the delivery of layered video streams to users with different propagation conditions. The goal of the proposed model is to minimize the user energy consumption. That goal is achieved by minimizing the time required by each user to receive the broadcast data via an efficient power transmission allocation model. A key point in our system model is that the reliability of layered video communications is ensured by means of the Random Linear Network Coding (RLNC) approach. Analytical results show that the proposed resource allocation model ensures the desired quality of service constraints, while the user energy footprint is significantly reduced.Comment: Proc. of IEEE ICC 2015, Selected Areas in Communications Symposium - Green Communications Track, to appea

    Urban Microclimate and Traffic Monitoring with Mobile Wireless Sensor Networks

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    Climate is usually defined as the average of the atmospheric conditions over both an extended period of time and a large region. Small scale patterns of climate resulting from the combined influence of topography, urban buildings structure, watercourses, vegetation, are known as microclimates, which refers to a specific site or location. The microclimate scale may be at the level of a settlement (urban or rural), neighborhood, cluster, street or buffer space in between buildings or within the building itself. Specifically, the dispersion and dilution of air pollutants emitted by vehicles is one of the most investigated topics within urban meteorology, for its fundamental impact on the environment affecting cities of all sizes. This issues concern the average and peak values of various air pollutants as well as their temporal trends and spatial variability. The accurate detection of these values might be advantageously exploited by public authorities to better plan the public and private transportation by evaluating the impact on people health, while controlling the greenhouse phenomenon. As the unpredictable nature of a climate variations requires an incessant and ubiquitous sensing,Wireless Sensor Networks (WSNs) represent a key technology for environmental monitoring, hazard detection and, consequently, for decision making (Martinez et al., 2004). A WSN is designed to be self-configuring and independent from any pre-existing infrastructure, being composed of a large number of elementary Sensor Nodes (SNs) that can be large-scale deployed with small installation and maintenance costs. Literature contains several examples of frameworks for evaluating the urban air quality with WSNs, as it is reported in (Santini et al., 2008). In addition, in (Cordova-Lopez et al., 2007) it is addressed the monitoring of exhaust and environmental pollution through the use of WSN and GIS technology. As micro-climate monitoring usually requires deploying a large number of measurement tools, in (Shu-Chiung et al., 2009) it is adopted vehicular wireless sensor networks (VWSNs) approach to reduce system complexity, while achieving fine-grainedmonitoring. Another aspect strictly correlated with microclimate establishment is represented by the ecologic footprint of traffic congestion due to inefficient traffic management. As a consequence, an increasing number of cities are going to develop intelligent transport system (ITS) as an approach to harmonize roads and vehicles in optimized and green paths. ITSs involves several technologies as advanced informatics, data communications and transmissions, electronics and computer control with the aim of real-time traffic reporting and alerting. Such a framework allows remote operation management and self-configuration of traffic flows, as well as

    The Folding process of Human Profilin-1, a novel protein associated with familial amyotrophic lateral sclerosis

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    Human profilin-1 is a novel protein associated with a recently discovered form of familial amyotrophic lateral sclerosis. This urges the characterization of possible conformational states, different from the fully folded state, potentially able to initiate self-assembly. Under native conditions, profilin-1 is monomeric and possesses a well-defined secondary and tertiary structure. When incubated at low pH or with high urea concentrations, profilin-1 remains monomeric but populates unfolded states exhibiting larger hydrodynamic radius and disordered structure, as assessed by dynamic light scattering, far-UV circular dichroism and intrinsic fluorescence. Refolding from the urea-unfolded state was studied at equilibrium and in real-time using a stopped-flow apparatus. The results obtained with intrinsic fluorescence and circular dichroism indicate a single phase without significant changes of the corresponding signals before the major refolding transition. However, such a transition is preceded by a burst phase with an observed increase of ANS fluorescence, which indicates the conversion into a transiently populated collapsed state possessing solvent-exposed hydrophobic clusters. Kinetic analysis reveals that such state has a conformational stability comparable to that of the fully unfolded state. To our knowledge, profilin-1 is the first example of an amyloid-related protein where folding occurs in the absence of thermodynamically stable partially folded states

    A Hierarchical Communication Architecture for Oceanic Survelliance Applications

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    The interest in monitoring applications using underwater sensor networks has been growing in recent years. The severe communication restrictions imposed by underwater channels make that efficient monitoring be a challenging task. Though a lot of research has been conducted on underwater sensor networks, there are only few concrete applications to a real-world case study. In this work, hence, we propose a general three tier architecture leveraging low cost wireless technologies for acoustic communications between underwater sensors and standard technologies, Zigbee and Wireless Fidelity (WiFi), for water surface communications. We have selected a suitable Medium Access Control (MAC) layer, after making a comparison with some common MAC protocols. Thus the performance of the overall system in terms of Signals Discarding Rate (SDR), signalling delay at the surface gateway as well as the percentage of true detection have been evaluated by simulation, pointing out good results which give evidence in applicability’s favour

    FOG-oriented Joint Computing and Networking: the GAUChO Project Vision

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    This paper presents a novel architectural principle for distributed and heterogeneous systems integrating Fog Computing and Networking approaches, which has been proposed within the “Green Adaptive Fog Computing and Networking Architecture” (GAUChO) project, funded by the MIUR Progetti di Ricerca di Rilevante Interesse Nazionale (PRIN) Bando 2015 - grant 2015YPXH4W-004. In particular a modular and flexible platform has been designed and developed, supporting low-latency and energy-efficiency applications as well as security, self-adaptation, and spectrum efficiency by means of a strict collaboration among devices. Specifically, the focus here is on the design of an integrated protocol architecture supporting mobile Fog-oriented services, and the developed Fog computing testbeds
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