Search results for "TELECOMMUNICATIONS"
showing 10 items of 1639 documents
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…
Performance of the Glass Block in Photovoltaic Generation
2015
In this article is presented the preliminary evaluation of the performance of radiation transmission of glass block, used in support of photovoltaic cells, investigating different internal surface points of the block, which are subject to different shading during daylight hours. The aim is to establish how the edging setting, the only opaque element, can reduce the amount of light radiation during the day, introducing in this way a reduction of efficiency of the entire generation system. The generation system can be based on traditional photovoltaic cells or on the most suitable dye sensitized solar cells. An experimental measurement setup employing a microprocessor-based instrument has bee…
Ultra-Wideband Radio Signals Distribution in FTTH Networks
2008
[EN] The use of an ultra-wideband (UWB) radio technique is proposed as a viable solution for the distribution of high-definition audio/video content in fiber-to-the-home (FTTH) networks. The approach suitability is demonstrated by the transmission of standards-based UWB signals at 1.25 Gb/s along different FTTH fiber links with 25 km up to 60 kin of standard single-mode fiber length in a laboratory experiment. Experimental results suggest that orthogonal frequency-division-multiplexed UWB signals exhibit better transmission performance in FFTH networks than impulse radio UWB signals.
Analysis of the accuracy of fiber-optic strain transducers installed by using composite smart patches
2015
The aim of this work is to investigate the accuracy of fiber-optic strain transducer related to the incomplete load transmission that can occur on composite smart patches used as base support for the installation of such transducer, commonly used for structural monitoring of concrete elements. In detail, since the dimensions of the transducer are generally very small compared to those of the structural element being monitored, attention is given not to the global reinforcement effect, which occurs when the transducer alters the entire strain field of the transversal section of the monitored element, but rather to the so-called local reinforcement effect, which is due to an incomplete load …
Fiber-Optic Insulating Link In A Telecommunication System For An Electric Power Plant
1990
The paper presents a fiber-optic insulating link coupling electric power substation with a dispa-tching telecommunication center. The advantages of employing the FO link in the power plant telecommunication system include insulating properties, resistance to EMI and high transmission capacity. The technical and economical analyses are complemented with the example of an application of the link to the 110/15 kV station. The two-directional communication system provides transmission of voice, telemetry, telesignalization and remote control signals.
Fiber - Optic Loop Network With Active Nodes For An Electrical Power Plant
1990
This paper presents a fiber optic loop network for a measurement and control system of an electric power plant. The network consists of the central computer terminal, the set of specially distributed digital FO links and local station installed at the important power facilities. The well-known FO link advantages contribUte to high reliability and safety of work of the system. The operation of the loop network, treated as an autonomous one, is controlled by a microcomputer system. Transmission protocols and the cooperation with the local station are also described. The proposed loop network model is illustrated with an example of the laboratory - scale system.
Multiservice Optical Fibre Local Area Networks For Data Transmission And Telemetry In The Electric Power Industry
1986
The paper contains a review of a few of experimental optical fibre multiservice and multibranch local area networks /LANs/. Systems accomplish transmission, distribution and processing of analog or digital signals from numerous sources or measurement terminals. The authors put stress also on the possibility of combining transmission properties of fiber optic networks with fibre optic sensors. Several construction problems and chosen properties of multiport /multiterminal/ optical buses /networks/ have been considered. All examination systems of optical fibre LANs are discussed in respect of application them as telemetric, transmission, telesignaling and telecontrol systems for the power ele…
<title>Fiber optic monitoring buses with binary on-off sensors</title>
1999
This paper presents general theoretical considerations of complex-structure optical fiber networks (buses) with binary `on-off' fiber optic sensors and fiber optic transmission lines for monitoring, diagnostic or measurement systems. The principles of fiber optic serial and parallel buses and various types of intensity fiber optic binary sensors are described as well as the advantages and disadvantages of the individual types of networks. The choice of the use of fiber optic technology rather than other techniques is discussed. Special emphasis was put on the role and function of optoelectronic and optical fiber devices in harsh environments. Theoretical considerations are illustrated by th…