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Performance of Cognitive Spectrum Sensing Based on Energy Detector in Fading Channels

Procedia Computer Science 2015年 65卷 140-147页

作者： Fabrício B.S. de Carvalho Waslon T.A. Lopes Marcelo S. Alencar Post-Graduate Program in Electrical Engineering – PPgEE – COPELE Federal University of Campina Grande Department of Electrical Engineering Campina Grande-PB 58429-900 Brazil Federal University of Paraíba Department of Electrical Engineering João Pessoa-PB 58051-970 PO BOX 5115 Brazil Institute of Advanced Studies in Communications (Iecom) Campina Grande-PB 58109-970 Brazil

Spectrum scarcity and the inefficient use of the electromagnetic spectrum motivated the development of Cognitive Radio (CR), which aims to extend the spectral efficiency, with opportunistic access to the available frequency bands. Energy Detection (ED) is the most adopted spectrum sensing technique for cognitive radio applications due to its simplicity. However, fading effects are usually simplified or discarded when evaluating the energy detector performance in spectrum sensing. This paper presents the performance evaluation of cognitive spectrum sensing, based on energy detector, for fading channels. The objective is to analyze how the use of various fading models affect the spectral detection in cognitive networks. Rayleigh, Rice, Nakagami-m and Lognormal fading channels are considered, and the results favor the use of ED when the channel is subject to Lognormal fading.

关键词： Cognitive Radio Spectrum Sensing Energy Detector Fading Channels

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An automatic thermal cycling based test platform for thermoelectric generator testing

An automatic thermal cycling based test platform for thermoe...

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IEEE Instrumentation and Measurement Technology Conference

作者： Julio Cezar de Cerqueira Veras Júlio Cezar de Cerqueira Véras Débora Alburquerque Vieira Ewerton C. S. Melo Cleonilson Protásio de Souza Coordination Section of Electronics Federal Institute of Pernambuco - IFPE Garanhuns Brazil Post-Graduate Program in Electrical Engineering - PPgEE - COPELE Federal University of Campina Grande - UFCG Paraíba Brazil Department of Electrical Engineering Federal University of Paraíba - UFPB João Pessoa Paraíba Brazil

Thermoelectric (TE) modules are solid-state devices that convert directly thermal energy in electrical energy. However, they can undergo performance degradation due to thermal cycling. In the present study, a control-based test platform that is capable to apply specific thermal cycling pattern at periodic intervals is presented in order to evaluate performance degradation that influence the TE module lifetime. Using this test platform, some parameters and the figure of merit ZT of a commercial TE module are measured before and after thermal cycling application. An important feature of the proposed platform is that the applied thermal cycling is bipolar, that is, it is possible to apply positive or negative temperature difference and, through this, performance degradation would be observed after only 548 thermal cycles much lower than previous works.

关键词： Temperature measurement Thermal degradation Degradation Voltage measurement Thermal resistance Heating Conductivity

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Structuring a portfolio for selecting and prioritizing textile products 8

Structuring a portfolio for selecting and prioritizing texti...

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8th International Conference on Industrial engineering and Industrial Management, CIO 2014, 20th International Conference on Industrial engineering and Operations Management, ICIEOM 2014 and International IIE Conference, IIIE 2014

作者： Loos, Maurício Johnny Cauchick-Miguel, Paulo Augusto Post-Graduate Program in Production Engineering Campus Universitário Trindade Federal University of Santa Catarina Florianópolis SC Brazil

ISBN: (纸本)9783319140773

The objective of this paper is to demonstrate a proposal on product portfolio management for the development of new products in a textile company. The research methods address the application of real data from the studied company. This work is characterized both as conceptual and field-based research. It constructs a proposal based on existing theory and involves an empirical application of that proposal. By using the portfolio selection and prioritization proposal, the company was able to select new products for development in a structured way. As continuity for this work, the paper suggests the application of product selection and prioritization for other organizations. © Springer International Publishing Switzerland 2015.

关键词： Project management

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An ontology-driven framework to support scenario representation in a 3D operator training simulator 4

An ontology-driven framework to support scenario representat...

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4th International Conference on Simulation and Modeling Methodologies, Technologies and Applications, SIMULTECH 2014

作者： Filho, Flávio Torres de Fátima Queiroz Vieira, Maria Post-Graduate Program in Electrical Engineering - PPgEE - COPELE Campina Grande Brazil Department of Electrical Engineering Federal University of Campina Grande Campina Grande Brazil

ISBN: (纸本)9789897580383

This paper presents a framework to support the development of three-dimensional virtual scenarios for an operator training simulator for electrical systems. Given the need to represent a variety of scenarios of interest, this can be an effort and time consuming task. The proposed framework promotes a systematic approach when building scenarios and is supported by tools from the ontology-based domain. An editing tool is also under construction. As it will be discussed in the paper, this approach resulted in the simplification of the scenario building process which is achieved by interchanging descriptions at different levels of abstraction. The descriptions concern the situation to be represented;plant objects' representation, both visual and behavioural, the latter represented as Coloured Petri Nets (CPN) models. © 2014 SciTePress. All rights reserved.

关键词： Ontology

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A New Approach for SSVEP Detection Using PARAFAC and Canonical Correlation Analysis

A New Approach for SSVEP Detection Using PARAFAC and Canonic...

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Annual International Conference of the IEEE engineering in Medicine and Biology Society

作者： Richard Tell Saeed Pouryazdian Andre Ferreira Soosan Beheshti Sridhar Krishnan Teodiano Bastos Post-Graduate Program in Electrical Engineering (PPGEE). UFES. Av. Fernando Ferrari 514. Vitoria Brazil. Department of Electrical and Computer Engineering. Ryerson University. 350 Victoria St Toronto ON M5B 2K3 Canada.

ISBN: (纸本)9781424492695

This paper presents a new way for automatic detection of SSVEPs through correlation analysis between tensor models. 3-way EEG tensor of channel x frequency x time is decomposed into constituting factor matrices using PARAFAC model. PARAFAC analysis of EEG tensor enables us to decompose multichannel EEG into constituting temporal, spectral and spatial signatures. SSVEPs characterized with localized spectral and spatial signatures are then detected exploiting a correlation analysis between extracted signatures of the EEG tensor and the corresponding simulated signatures of all target SSVEP signals. The SSVEP that has the highest correlation is selected as the intended target. Two flickers blinking at 8 and 13 Hz were used as visual stimuli and the detection was performed based on data packets of 1 second without overlapping. Five subjects participated in the experiments and the highest classification rate of 83.34% was achieved, leading to the Information Transfer Rate (ITR) of 21.01 bits/min.

关键词： EEG SSVEPs PARAFAC

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Cognitive Vehicular Networks: An Overview

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Procedia Computer Science 2015年 65卷 107-114页

作者： Fabrício B.S. de Carvalho Waslon T.A. Lopes Marcelo S. Alencar José V.S. Filho Post-Graduate Program in Electrical Engineering – PPgEE – COPELE Federal University of Campina Grande Department of Electrical Engineering Campina Grande-PB 58429-900 Brazil Federal University of Paraíba Department of Electrical Engineering João Pessoa-PB 58051-970 PO BOX 5115 Brazil Institute of Advanced Studies in Communications (Iecom) Campina Grande-PB 58109-970 Brazil Federal University of Reconcavo Baiano Cruz das Almas-BA Brazil

Cognitive Radio (CR) is extending the applications of wireless communications worldwide. Cognitive radio verifies the electromagnetic spectrum availability and permits the modification of the transmission parameters using the interaction with the environment. The goal is to opportunistically occupy spectral bands with minimum interference to other users or applications. Cognitive radio for Vehicular Ad hoc Networks (CRVs or CR-VANETs) is a new trend in the automotive market. Recent and future vehicles will offer functionalities for the transmission of intra-vehicular commands and dynamic access to wireless services, while the car is in transit. This paper describes the cognitive radio technology and its signal processing perspectives for the automotive market.

关键词： Cognitive Radio Vehicular Networks CRVs CR-VANETs V2V V2I.

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Low-power energy conversion systems with two-phase PM machine and a rectifier with reduced number of controlled switches

Low-power energy conversion systems with two-phase PM machin...

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作者： Jacobina, Cursino B. Melo, Victor F.M.B. Da Bahia, Filipe A.C. Da Silva, Italo Roger F.M.P. Electrical Engineering Department Federal University of Campina Grande - UFCG Campina Grande Paraíba Brazil Post-Graduate Program in Electrical Engineering - PPgEE - COPELE UFCG Brazil

ISBN: (纸本)9781479956982

This paper presents two energy conversion systems with two-phase permanent magnet (PM) machine and a rectifier with reduced number of controlled switches. The topologies are conceived with the purpose of converting wind energy into electrical energy (i.e., a wind energy conversion system (WECS)) for low power applications. Compared with some three-phase generation systems with reduced number of controlled switches, the proposed topologies permit obtaining sinusoidal controlled machine currents, reducing dc-link voltage and dq currents low harmonic distortion. © 2014 IEEE.

关键词： Topology

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Group Delay Analysis of Folded Multi-layer C-Sections Used in Encoding of Chipless RFID Tag

Group Delay Analysis of Folded Multi-layer C-Sections Used i...

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SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference

作者： Raquel Aline Araujo Rodrigues Edmar Candeia Gurjao Francisco Marcos de Assis Smail Tedjini Etienne Perret Post-Graduate Program in Electrical Engineering - COPELE Radiometry Research Group Electrical Engineering Department (DEE) Federal University of Campina Grande (UFCG) Grenoble Institute of Technology/LCIS

ISBN: (纸本)9781467394932

Researches on modern wireless identification methods have been focused on RFID techniques and in particular on chipless solutions. A parametric study of folded multi-layer C-sections fabricated on flexible substrates and a chipless RFID tag with single group of folded C-sections are presented in this paper. Full-wave simulations have been done for the folded multi-layer C-section and the chipless RFID tag. The obtained results confirm the feasibility of the utilization of this concept with multi-layer C-sections in temporal multi-frequency encoding technique based on group delay. It has been found that the techniques with folded multi-layer structure offer a significant amount of group delay and highly narrow band delay peaks.

关键词： Chipless RFID Tag Folded multi-layer C-sections Group delay

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Viability of using monofilament polyamide lines in AC live work 33

Viability of using monofilament polyamide lines in AC live w...

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33rd Electrical Insulation Conference, EIC 2015

作者： Gomes, A.M.M.B. Ferreira, T.V. Araujo, J.F. Barbosa, L.A. Lucena, M.D. Costa, E.G. Post-Graduate Program in Electrical Engineering PPgEE-COPELE Department of Transmission Lines Recife Pernambuco Brazil Department of Electrical Engineering Federal Uruversity of Campina Grande Campina Grande Paraiba Brazil

ISBN: (纸本)9781479973521

This article presents considerations and results of practical tests on the use of insulating polyamide monofilament line as the likely replacement for the traditional non-insulating multifilament ropes, employed in online interventions. The use of insulating polyamide monofilament line decreases the necessary time in online interventions, since some safety distances can be reduced. Furthermore, its cost is less than UD 0.08 per meter. The line samples were firstly mechanically aged, providing five different degrees of degradation. Electrical tests were performed in all samples, under three conditions: clean, moistened with tap water and moistened with saline water. A traditional insulating hot stick was taken as reference, due to its reliability and long term use in online interventions. The results are promising and indicate a desirable scenario, since the use of such line reduces time and effort, and also increases the process safety. © 2015 IEEE.

关键词： Insulation

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Proposal of a Brain Computer Interface to command an autonomous car

Proposal of a Brain Computer Interface to command an autonom...

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Biosignals and Biorobotics Conference (BRC), ISSNIP

作者： Javier Castillo Sandra Müller Eduardo Caicedo Alberto Ferreira De Souza Teodiano Bastos Post-Graduate Program of Electrical Engineering Federal University of Espirito Santo Vitoria Brazil Post-Graduate Program of Electrical Engineering University of Valle Cali Valle Colombia Post-Graduate Program of Informatics Federal University of Espirito Santo Vitoria Brazil

This paper presents a proposal of Brain Computer Interface (BCI) to command an autonomous car. This BCI is based on the paradigm of visual evoked potentials (VEP) and event-related desynchronization (ERD). A menu interface is presented to the user with disabilities in order he/she can choose a destination for the autonomous car. The selection of the final destination is performed using visual stimuli flickering at different frequencies, analyzed through the analysis of brain signals present at the occipital region of the user's scalp. The power spectrum of these signals is then obtained, in order to get the frequency of the visual stimulation. Preliminary tests were performed with healthy users and people with disabilities, which reached an average success rate above 90%. The proposed system is also capable of turning on/off the stimuli, thus reducing the fatigue associated with particular visual stimuli.

关键词： Brain-computer interfaces Mobile robots Visualization Equations Proposals Educational institutions Navigation

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