Search results for "Telecommunication"
showing 10 items of 1769 documents
Experimental Investigation for Degradation Analysis of an RC Italian Viaduct and Retrofitting Design
2020
AbstractThe degradation state of RC bridge structures is one of the most important and difficult aspects to be interpreted. For these structures, structural analysis using FEM requires a reliable d...
Risk evaluation and creep in conventional conductors caused by high temperature operation
2008
The advent of electricity market deregulation, the increased operating and overload temperatures of transmission line conductors have caused concern among TSOs (Transmission System Operators) and DSOs (Distribution System Operators) about the effect of elevated temperatures on conventional bare conductors of existing line. Nowadays building new lines is very difficult cause of increased costs to obtain rights of way, public intervention, etc.... Cost and lead times required to place new lines into service are now increased and the business in electric market is reduced for the limited possibility of transmission. Therefore, utilities are attempting to gain as much capacity as possible modif…
On the roadmap to supergrid in Sicily: LiDAR technology and HTLS conductors for uprating the 150 kV lines
2014
Difficulties in building new power lines in Italy because of authorization problems, and the production of electricity from renewable sources growing more and more, induces Terna S.p.A. (Italian TSO) to take advantage of existing overhead transmission lines. In order to increase the transmission capacity, Terna has used a software in GIS (Geographic Information System) environment which allows for the management of the interferences according to all the legislative bonds by referring to the LIDAR (Laser Imaging Detection and Ranging) remote sensing technology. This paper, after a description of the GIS and the LiDAR technology, shows how the calculation of the current capacity of some High …
GIS systems and LIDAR technology for the operation of HV lines. Sicilian transmission network applications
2013
The difficulties to build new power lines within the national territory cause of authorization problems, and the evermore growing production of electricity from renewable sources, induces Terna S.p.A. (Italian TSO) to take advantage of existing overhead transmission lines. Therefore, in order to increase the transmission capacity, and to optimize the maintenance and management of power lines, for some years Terna has been using a software in GIS environment (Geographic Information System) that referring to the LIDAR (Laser Imaging Detection and Ranging) remote sensing technology, allows to manage the interferences according to all the requirements and legislative bonds and to fulfill the im…
Decoupled control scheme of the grid-connected split-source inverter for renewable energy sources
2016
Grid-connected power conversion systems for renewable energy sources must fulfill several requirements, including high efficiency, reduced cost and complexity, and, quite often, also boost capabilities from the dc sources to the ac power grid. For such applications, single-stage power converters with boost capabilities offer some potential advantages. Among several proposed options, split-source inverter (SSI) has been recently investigated. This paper proposes a decoupled control scheme for the SSIs, where the common mode term of the ac modulation signals is used to control the dc input current. Thus, the dc input current and ac output current can be controlled independently. The proposed …
Policy-based channel access mechanism selection for QoS provision in IEEE 802.11e
2007
The appearance of the 802.11e standard made the 802.11 wireless local area networks (WLANs) capable of providing different levels of quality of service (QoS). This standard defines two new channel access mechanisms (CAMs), namely the enhanced distributed channel access (EDCA) and the HCF controlled channel access (HCCA). The introduction of two CAMs increases the complexity of traffic management, since now not only the available resources have to be distributed, but also the optimal CAM for each data flow has to be selected. However, the best CAM selection algorithm is still not clear. This paper presents and analyses different CAM selection policies in order to derive the best-suited strat…
Six-years-long effects of the Italian policies for photovoltaics on the grid parity of grid-connected photovoltaic systems installed in urban contexts
2017
Abstract The purpose of this study is investigating the grid parity (GP) time and the levelized cost of energy (LCOE) of grid-connected photovoltaic (PV) systems installed in densely urbanized contexts. The analysis, which was elaborated for three Italian cities, considered the effects of the promoting policies enacted by the Italian government from June 2010 to May 2016. An appropriate methodology was applied with the aim of realistically defining the energy produced by PV systems installed on buildings with different roof types and number of floors. The calculus of the disbursements considered the operating, maintenance and insurance costs and the wear of PV panels and inverters. The resu…
A dynamic channel access strategy for underlay cognitive radio networks: Markov modelling and performance evaluation
2015
Unlike in overlay cognitive radio networks, secondary users in underlay cognitive radio networks can access licensed spectrum even at the presence of a primary user, given that the interference caused by the secondary transmission is lower than a pre-specified threshold. Based on this underlay access principle, we propose in this paper a dynamic channel access strategy for multi-channel cognitive radio networks. Different from existing underlay access techniques, channel assembling, spectrum adaptation and restricted channel occupancy are also considered in the proposed strategy in order to achieve better performance in the secondary network. Accordingly, a partial channel occupancy mode, w…
Economic evaluation of PV system for EV charging stations: Comparison between matching maximum orientation and storage system employment
2016
This article addresses the problem of the choice of a generation system to be implemented to reduce the impact of charging electric vehicles at University. Based on the behaviour of the student population, it is identified the electrical load. Two possible solutions are evaluated in order to manage the peak load: an orientation of the panels in order to increase the power at defined time and the use of storage system. The main strength and weakness points of two systems are investigated by taking into account the Levelized Cost of Energy.
Scars Collaborative Telediagnosis Platform Using Adaptive Image Flow
2013
International audience; Telemedicine has been developed to allow practitioners to remotely connect with patients and with other medical staff.We propose a new system (hardware and software), named DICODERM (COllaborative DIagnosis of DERMatosis), which makes it possible to monitor the evolution of scars after the excision of a tumorous dermatosis (like melanoma). The hardware part of this system is composed of a new optical innovative probe with which two types of images can be acquired simultaneously: anatomic with a white light image and functional with a fluorescence image (using autofluorescence from the protoporphyrin within the cancer cell). The software part is composed of two compon…