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作者： Negri, L.H. Lopes, H.S. Muller, M. Fabris, J.L. Paterno, A.S. Graduate Program in Electrical and Computer Engineering Federal University of Technology Paraná Brazil Department of Electrical Engineering Santa Catarina State University Brazil

This work proposes an efficient approach to recover the mechanical strain profile applied on fibre Bragg grating sensors. The proposed method is based on differential evolution and uses only the sensor reflectivity, without requiring phase information. The method has been shown to be highly parallelisable, with the fitness evaluation procedure implemented on graphical processing units. Experiments were performed to evaluate the performance of the method on three distinct graphic processing units (GPU), under a series of increasing loads. An enhancement up to three orders of magnitude in performance was obtained in respect to other evolutionary method proposed in the literature for the same purpose. Furthermore, it was observed that, for smaller problem sizes, the GPU clock rate was more significant than the number of cores of the GPU. © 2016 Inderscience Enterprises Ltd.

关键词： Graphics processing unit

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Polycrystalline ZrTe5 Parametrized as a Narrow-Band-Gap Semiconductor for Thermoelectric Performance

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Physical Review Applied 2018年第1期9卷 014025-014025页

作者： Samuel A. Miller Ian Witting Umut Aydemir Lintao Peng Alexander J. E. Rettie Prashun Gorai Duck Young Chung Mercouri G. Kanatzidis Matthew Grayson Vladan Stevanović Eric S. Toberer G. Jeffrey Snyder Department of Materials Science and Engineering Northwestern University Evanston Illinois 60208 USA Department of Chemistry Koç University Sariyer Istanbul 34450 Turkey Applied Physics Graduate Program Northwestern University Evanston Illinois 60208 USA Materials Science Division Argonne National Laboratory Argonne Illinois 60439 USA National Renewable Energy Laboratory Golden Colorado 80401 USA Department of Metallurgical and Materials Engineering Colorado School of Mines Golden Colorado 80401 USA Department of Chemistry Northwestern University Evanston Illinois 60208 USA Department of Electrical Engineering and Computer Science Northwestern University Evanston Illinois 60208 USA Department of Physics Colorado School of Mines Golden Colorado 80401 USA

The transition-metal pentatellurides HfTe5 and ZrTe5 have been studied for their exotic transport properties with much debate over the transport mechanism, band gap, and cause of the resistivity behavior, including a large low-temperature resistivity peak. Single crystals grown by the chemical-vapor-transport method have shown an n−p transition of the Seebeck coefficient at the same temperature as a peak in the resistivity. We show that behavior similar to that of single crystals can be observed in iodine-doped polycrystalline samples but that undoped polycrystalline samples exhibit drastically different properties: they are p type over the entire temperature range. Additionally, the thermal conductivity for polycrystalline samples is much lower, 1.5 Wm−1 K−1, than previously reported for single crystals. It is found that the polycrystalline ZrTe5 system can be modeled as a simple semiconductor with conduction and valence bands both contributing to transport, separated by a band gap of 20 meV. This model demonstrates to first order that a simple two-band model can explain the transition from n- to p-type behavior and the cause of the anomalous resistivity peak. Combined with the experimental data, the two-band model shows that carrier concentration variation is responsible for differences in behavior between samples. Using the two-band model, the thermoelectric performance at different doping levels is predicted, finding zT=0.2 and 0.1 for p and n type, respectively, at 300 K, and zT=0.23 and 0.32 for p and n type at 600 K. Given the reasonably high zT that is comparable in magnitude for both n and p type, a thermoelectric device with a single compound used for both legs is feasible.

关键词： Band gap Charge density waves Hall effect Semimetals Spin-orbit coupling Thermoelectric effects Chalcogenides Semiconductor compounds

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Acoustic supercoupling in a zero-compressibility waveguide

arXiv

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arXiv 2018年

作者： Esfahlani, H. Byrne, M.S. McDermott, M. Alù, A. Photonics Initiative Advanced Science Research Center City University of New York New York CityNY10031 United States Department of Electrical and Computer Engineering University of Texas at Austin AustinTX78712 United States LausanneCH-1015 Switzerland Naval Surface Warfare Center Carderock Division West BethesdaMD20817 United States Physics Program Graduate Center City University of New York New York CityNY10026 United States Department of Electrical Engineering City College of New York New York CityNY10031 United States

Funneling acoustic waves through largely mismatched channels is of fundamental importance to tailor and transmit sound for a variety of applications. In electromagnetics, zero-permittivity metamaterials have been used to enhance the coupling of energy in and out of ultranarrow channels, based on a phenomenon known as supercoupling. These metamaterial channels can support total transmission and complete phase uniformity, independent of the channel length, despite being geometrically mismatched to their input and output ports. In the field of acoustics, this phenomenon is challenging to achieve, since it requires zero-density metamaterials, typically realized with waveguides periodically loaded with membranes or resonators. Compared to electromagnetics, the additional challenge is due to the fact that conventional acoustic waveguides do not support a cut-off for the dominant mode of propagation, and therefore zero-index can be achieved only based on a collective resonance of the loading elements. Here we propose and experimentally realize acoustic supercoupling in a dual regime, using a compressibility-near-zero acoustic channel. Rather than engineering the channel with subwavelength inclusions, we operate at the cut-off of a higher-order acoustic mode, demonstrating the realization and efficient excitation of a zero-compressibility waveguide with effective soft boundaries. We experimentally verify strong transmission through a largely mismatched channel and uniform phase distribution, independent of the channel length. Our results open interesting pathways towards the realization of extreme acoustic parameters, and their implementation in relevant applications, such as ultrasound imaging, sonar technology, and sound transmission. Copyright © 2018, The Authors. All rights reserved.

关键词： Compressibility

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Abstracts

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JOURNAL OF SPINAL CORD MEDICINE 2021年第SUPPL 1期44卷 S278-S324页

作者： [Anonymous] Department of Medicine Division of Physical Medicine and Rehabilitation University of Toronto Toronto ON CA KITE - Toronto Rehabilitation Institute University Health Network Toronto ON CA Institute for Health Policy Management and Evaluation University of Toronto Toronto ON CA Rehabilitation Sciences Institute University of Toronto Toronto ON CA Institute of Medical Sciences University of Toronto Toronto ON CA. Rehabilitation Sciences Institute University of Toronto ON CA KITE Research Institute-Toronto Rehab-University Health Network Toronto ON CA Physical Therapy Department University of Toronto ON CA Praxis Spinal Cord Institute Vancouver BC Université de Montréal (École de réadaptation) Montreal QC CA Institut de réadaptation Gingras-Linsay-de-Montréal Montreal QC CA Division of Physical Medicine & Rehabilitation Department of Medicine Faculty of Medicine & Dentistry University of Alberta Edmonton AB CA University of Calgary Calgary AB CA Alberta Health Services Centre for Family Medicine Kitchener ON CA McMaster University Department of Family Medicine Hamilton ON CA Dept. of Physical Therapy University of Toronto Toronto ON CA KITE-University Health Network Toronto ON CA Praxis Spinal Cord Institute Vancouver BC CA Center for Interdisciplinary Research in Rehabilitation and Social Integration (CIRRIS) Quebec City QC CA Dept. of Rehabilitation Laval University Quebec City QC CA Institute of Health Policy Management and Evaluation University of Toronto Toronto ON CA School of Rehabilitation Science University of Saskatchewan Saskatoon SK CA Ontario Neurotrauma Foundation Toronto ON CA Canadian Spinal Research Organization Toronto ON CA CIUSSS du Centre-Sud-de-l ‘Île-de-Montréal (Installation Gingras-Lindsay) Montréal QC CA École de réadaptation Université de Montréal Montréal QC CA First Steps Wellness Centre Regina SK CA Stan Cassidy Centre for Rehabilitation Horizon Health Network Fredericton NB CA Departmen

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A Hyper-Heuristic in MOEA/D-DRA Using the Upper Confidence Bound Technique

A Hyper-Heuristic in MOEA/D-DRA Using the Upper Confidence B...

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Brazilian Conference on Intelligent Systems (BRACIS)

作者： Lucas Prestes Myriam Regattieri de Biase da Silva Delgado Richard Aderbal Goncalves Carolina Paula de Almeida Aurora Trinidad Pozo Universidade Tecnologica Federal do Parana Curitiba PR BR Graduate Program in Electrical and Computer Engineering UTFPR Universidade Estadual do Centro-Oeste Guarapuava PR BR Computer Science Department UNICENTRO Computer Science Department UFPR

The Multi-Objective Evolutionary Algorithm based on Decomposition with Dynamical Resource Allocation (MOEA/D-DRA) has obtained very good results on various multi-objective optimization problems in the past few years. This paper focuses on an attempt to improve even more its performance by introducing a hyper-heuristic mechanism to select the best set of its operators and parameters. In this paper we use Upper Confidence Bound (UCB) as the basis of the hyper-heuristic, and test three versions of the proposed approach. Four well known benchmarks (CEC 2009, WFG, DTLZ and ZDT) and a quality indicator (hypervolume) are used to analyze the performance of the three variants. The proposed approach is compared with the original MOEA/D-DRA and the results show that tuning the parameters via UCB is an interesting alternative for a hyper-heuristic based version of MOEA/D-DRA on the addressed problems.

关键词： Optimization Sociology Statistics Evolutionary computation Benchmark testing Resource management Approximation algorithms

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Application of Message Security Application Using Vigenere Cipher Algorithm Utilizing One Time Pad (OTP) Algorithm as a Key Generator

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Journal of Physics: Conference Series 2019年第1期1363卷 012080-012080页

作者： Pardede, A M H Lorena Perbina Br Sitepu Zarlis, Muhammad Tulus Iskandar, Akbar Sriadhi, S Manurung, Rosida Tiurma Nurintan Asyiah Siregar Sari, Ayu Esteka Yunawati, Sri Mursyidah, M Mursalin, M Kurniasih, Nuning Kurniawan, Citra Winarno, Edy STMIK Kaputama Binjai Sumatera Utara Indonesia Department of Computer Science Universitas Sumatera Utara Medan Indonesia Department of Mathematics Universitas Sumatera Utara Medan Indonesia Department of Electrical Engineering Universitas Negeri Medan Indonesia Graduate Program in Scientific Psychology Universitas Kristen Maranatha Indonesia Department of Management STIE Labuhanbatu Sumatera Utara Indonesia Department of Management STIE Sakti Alam Kerinci Jambi Indonesia Program Study of Accounting Pasir Pengaraian University Riau Indonesia Departement of Information Technology and Computer Politeknik Negeri Lhokseumawe Aceh Indonesia Department of Mathematics Education Universitas Malikussaleh Aceh Indonesia Faculty of Communication Sciences Library and Information Science Program Universitas Padjadjaran Bandung Indonesia Department of Electrical Engineering Sekolah Tinggi Teknik Malang Indonesia Faculty of Information Technology Universitas Stikubank Semarang Indonesia

Cryptography is the science and art of maintaining the security of messages when messages are sent from one place to another. One of the ways securing the form of text message information is by the encryption process using the Vigenere Cipher algorithm and utilizing the One Time Pad (OTP) algorithm as a key generator, where the message will be random when it is opened. The message encryption process used the vigenere cipher algorithm while OTP is used to secure the key with the same formula. After this research has been done, an application was designed to secure text messages by converting the text message into a random message so that the message was unreadable due to a secret message that could not be known by others. The results achieved can secure an encrypted message that cannot be reopened and if those messages were reopened, they must be decrypted.

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Dual sensor for simultaneous measurement of electrical impedance and temperature during ice formation process

Dual sensor for simultaneous measurement of electrical imped...

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International Symposium on Instrumentation Systems, Circuits and Transducers (INSCIT)

作者： Jean Paulo Nakatu Longo José Rodolfo Galvão Jean Carlos Cardozo da Silva Cicero Martelli Rigoberto E. M. Morales Marco Jose da Silva Graduate Program in Electrical and Computer Engineering (CPGEI) Universidade Tecnológica Federal do Paraná Multiphase Flow Research Center (NUEM) Universidade Tecnológica Federal do Paraná

Impedance spectroscopy is often applied to characterize solids and fluids since each substance presents its own and sometimes unique impedance spectra. In industrial applications, impedance spectroscopy has the potential to monitor many processes such as those occurring in chemical reactors or liquid transportation in pipelines. In this paper, we introduce a sensor being able to perform measurements of impedance spectra (from few Hz to few MHz) allied to precise temperature measurements based on optical fiber Bragg grating sensors which was applied for monitoring ice formation, as exemplary process. The new sensor is described, calibrated and tested. The system was evaluated by measurements with known substances. Ice formation process was monitored and some findings are presented and discussed.

关键词： Ice Temperature measurement Impedance Temperature sensors Fiber gratings Permittivity

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Consistency of Surface Electromyography Assessment at Lower Limb Selected Muscles During Vertical Countermovement

Consistency of Surface Electromyography Assessment at Lower ...

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

作者： Carlos Rodrigues Miguel Correia Joao M. C. S. Abrantes Jurandir Nadal Marco A. Benedetti Rodrigues Centre for Biomedical Engineering Research INESC TEC Porto Portugal INESC TEC FEUP Department of Electrical and Computer Engineering University of Porto Porto Portugal MovLab ULHT PEB UFRJ PPGEE UFPE Graduate Program in Electrical Engineering Federal University of Pernambuco Recife Brazil

Given the difficulty of invasive methods to assess muscle action during natural human movement, surface electromyography (sEMG) has been increasingly used to capture muscle activity in relation to kinesiological analysis of specific tasks. Isolated isometric, concentric and eccentric forms of muscle action have been receiving the most attention for research purposes. Nevertheless natural muscle action frequently involves the use of a preceding eccentric muscle action as a form of potentiation of immediate muscle concentric action, in what is designated as muscle stretch-shortening cycle (SSC). The most frequently applied protocols for the evaluation of SSC on vertical jumps are by virtue of their reproducibility and control of experimental conditions, squat jump (SJ) without countermovement (CM), countermovement jump (CMJ) with long CM and drop jump (DJ) with short CM. The methods used to extract information and relationship of the captured signals also present a high diversity, with the question about the consistency of the methods and obtained results. The objective of this study is to evaluate the consistency of the analysis and results by applying different EMGs signal analysis techniques related to strategic muscle groups of the lower limbs at different countermovement evaluated in vertical jumps. Raw sEMG signals of 5 lower limb muscles of 6 subjects during SJ, CMJ and DJ were rectified, filtered and obtained their envelope, and then correlated (CR) for detection of synergistic, agonist and antagonist activity, applied principal component analysis (PCA) for the detection of uncorrelated components explaining maximum variability and normalized cross-correlation (CCRN) for detection of maximum correlations and time lag. CR of EMG envelopes presented higher coactivities (CoA) in DJ relative to SJ and these CoA superior to CMJ with greater synergy in DJ relative to SJ and CMJ that present several loop cycles corresponding to time lag of activity. CCRN of the EMG e

关键词： Muscles Correlation Electromyography Principal component analysis Eigenvalues and eigenfunctions Electronic mail Radio frequency

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A hybrid SARFIMA-FTS model for time series prediction in smart grids

A hybrid SARFIMA-FTS model for time series prediction in sma...

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IEEE International Conference on Fuzzy Systems (FUZZ-IEEE)

作者： Cidiney Silva Frederico Gadelha Guimarães Hossein Javedani Sadaei Vitor Nazário Coelho Graduate Program in Electrical Engineering-Federal University of Minas Gerais Belo Horizonte MG Brazil Departament of Electrical Engineering Universidade Federal de Minas Gerais Belo Horizonte MG Brazil Institute of Computer Science Universidade Federal Fluminense Niteroi Brazil

The intensive use of electricity in life and modern society implies increasing demand and the need for increasingly high reliability. Smart Grids (SG) are the next technological breakthrough to be achieved for the generation, transmission and distribution of energy. Historically, it has been sought to automate each of these systems to perform main and ancillary services. Robust forecasting methodologies are essential for planning and operation of SG. However, SG data presents the characteristics of long memory time series, which are a kind of stationary processes in such a way that there is always a statistical long range dependency between the current value and values in different times of the series. Motivated by this, we introduce a new hybrid model combining Seasonal Auto Regressive Fractionally Integrated Moving Average with high order Fuzzy Time Series (SARFIMA-FTS). We present comparative results of SARFIMA-FTS with other two methodologies solutions in microgrid data. The computational results show that the performance of the proposed SARFIMA-FTS method is quite competitive with other presented methods in literature using less parameters, hence it is an important tool for prediction in smart grids.

关键词： Mathematical model Time series analysis Forecasting Computational modeling Smart grids Electronic mail Robustness

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Evolutionary computation and swarm intelligence for the inference of gene regulatory networks

Evolutionary computation and swarm intelligence for the infe...

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作者： Hattori, Leandro Takeshi Lopes, Heitor Silvério Lopes, Fabrício Martins Graduate Program in Electrical and Computer Engineering Federal University of Technology ParanáCuritiba Brazil Graduate Program in Bioinformatics Federal University of Technology ParanáCornélio Procópio Brazil

The inference of gene regulatory networks (GRNs) from expression profiles is still an important challenge in bioinformatics research. The main difficulty of this problem is associated to the huge number of genes and the small number of samples available, as well as the intrinsic noise in the data acquisition process. In this context, this paper presents a feature selection approach to the identification of GRNs using optimisation strategies from evolutionary computation and swarm intelligence. As a case-study we used an artificial gene network (AGN) based on the scale-free topology. This AGN has 1,000 genes and was simulated with 500 temporal expression samples. The methods compared were: differential evolution (DE), bat algorithm (BAT) and artificial bee colony (ABC) algorithms. All algorithms used their standard control parameters and the same criterion function: the mean conditional entropy (MCE). This is an information theory measure, commonly adopted for various feature selection problems in the pattern recognition research field. The results showed that DE algorithm leaded to the best results than BAT and ABC in all comparisons, and the inferred network was more similar to the original network. Copyright © 2016 Inderscience Enterprises Ltd.

关键词： Evolutionary algorithms

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