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Coherently Enhanced Wireless Power Transfer

Physical Review Letters 2018年第14期120卷 143901-143901页

作者： Alex Krasnok Denis G. Baranov Andrey Generalov Sergey Li Andrea Alù Department of Electrical and Computer Engineering The University of Texas at Austin Austin Texas 78712 USA Department of Physics Chalmers University of Technology 412 96 Gothenburg Sweden Moscow Institute of Physics and Technology Dolgoprudny 141700 Russia Department of Electronics and Nanoengineering Aalto University 02150 Espoo Finland ITMO University St. Petersburg 197101 Russia Photonics Initiative Advanced Science Research Center City University of New York New York 10031 USA Physics Program Graduate Center City University of New York New York 10016 USA Department of Electrical Engineering City College of The City University of New York New York 10031 USA

Extraction of electromagnetic energy by an antenna from impinging external radiation is at the basis of wireless communications and wireless power transfer (WPT). The maximum of transferred energy is ensured when the antenna is conjugately matched, i.e., when it is resonant and it has an equal coupling with free space and its load. This condition, however, can be easily affected by changes in the environment, preventing optimal operation of a WPT system. Here, we introduce the concept of coherently enhanced WPT that allows us to bypass this difficulty and achieve dynamic control of power transfer. The approach relies on coherent excitation of the waveguide connected to the antenna load with a backward propagating signal of specific amplitude and phase. This signal creates a suitable interference pattern at the load resulting in a modification of the local wave impedance, which in turn enables conjugate matching and a largely increased amount of extracted energy. We develop a simple theoretical model describing this concept, demonstrate it with full-wave numerical simulations for the canonical example of a dipole antenna, and verify experimentally in both near-field and far-field regimes.

关键词： Electromagnetism engineering Light propagation, transmission & absorption Photonics

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Total variation superiorized conjugate gradient method for image reconstruction

arXiv

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arXiv 2017年

作者： Zibetti, Marcelo V. W. Lin, Chuan Herman, Gabor T. Graduate Program in Electrical Engineering and Computer Science Federal University of Technology - Paraná Curitiba80230-901 Brazil School of Electrical Engineering Southwest Jiaotong University Chengdu Sichuan610031 China Department of Computer Science Graduate Center City University of New York New YorkNY10016 United States

The conjugate gradient (CG) method is commonly used for the relatively-rapid solution of least squares problems. In image reconstruction, the problem can be ill-posed and also contaminated by noise;due to this, approaches such as regularization should be utilized. Total variation (TV) is a useful regularization penalty, frequently utilized in image reconstruction for generating images with sharp edges. When a non-quadratic norm is selected for regularization, as is the case for TV, then it is no longer possible to use CG. Nonlinear CG is an alternative, but it does not share the efficiency that CG shows with least squares and methods such as fast iterative shrinkage-thresholding algorithms (FISTA) are preferred for problems with TV norm. A different approach to including prior information is superiorization. In this paper it is shown that the conjugate gradient method can be superiorized. Five different CG variants are proposed, including preconditioned CG. The CG methods superiorized by the total variation norm are presented and their performance in image reconstruction is demonstrated. It is illustrated that some of the proposed variants of the superiorized CG method can produce reconstructions of superior quality to those produced by FISTA and in less computational time, due to the speed of the original CG for least squares problems. In the Appendix we examine the behavior of one of the superiorized CG methods (we call it S-CG);one of its input parameters is a positive number ". It is proved that, for any given " that is greater than the half-squared-residual for the least squares solution, S-CG terminates in a finite number of steps with an output for which the half-squared-residual is less than or equal to ". Importantly, it is also the case that the output will have a lower value of TV than what would be provided by unsuperiorized CG for the same value " of the half-squared residual. Copyright © 2017, The Authors. All rights reserved.

关键词： Conjugate gradient method

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Applying the MVC EA-IRPM to reporting-guidelines in medicine: A strategy that is a web system 4

Applying the MVC EA-IRPM to reporting-guidelines in medicine...

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4th IEEE EMBS International Conference on Biomedical and Health Informatics, BHI 2017

作者： Letouze, Patrick De Souza, J.I.M. Silva, Valeria Martins Climaco, Glaubos Chagas, F.B. Ishihara, Joao Y. Graduate Program of Computational Modeling of Systems Universidade Federal Do Tocantins Quadra 109 Norte Avenida NS-15 Palmas77001-090 Brazil Graduate Program of Systems' Engineering and Computation - PESC Universidade Federal Do Rio de Janeiro Rio de Janeiro Brazil Department of Informatics at the Universidade Federal Do Maranh/ Ao - UFMA Brazil Faculty of Computer Science Faculdade Pitagoras Imperatriz Imperatriz Brazil Faculty of Electrical Engineering Universidade de Brasília Brasília Brazil

ISBN: (纸本)9781509041794

Reporting-Guidelines in Medicine play an important role in promoting the quality of reports in health-related research. For instance, a poorly reported research may induce misinterpretation and inappropriate clinical settings. Basically, three major issues regarding Reporting-Guidelines in Medicine has to be addressed: (1) the existence of lots of reporting guidelines covering a broad spectrum of medical research increases the difficulties when reporting a medical research because it may not be clear which guidelines are applicable, or if all related guidelines are considered;(2) most guideline developers have not described how their guidance was developed, consequently tracking guidelines and features for evaluation, or even for correcting, may be not possible;(3) few guideline developers have evaluated the effectiveness of their guidance, then the real value that the guideline brings to reporting the research is not assured. Hence, we propose a solution to these three issues based on the Model-View-Controller Evolutionary Acquisition Interdisciplinary Research Project Management (MVC EA-IRPM) that is simultaneously a strategy and a web system for the development and management of reporting guidelines. © 2017 IEEE.

关键词： Clinical research

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The evolutionary history of 2,658 cancers (vol 578, pg 122, 2020)

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NATURE 2023年第7948期614卷 E42-E42页

作者： Gerstung, Moritz Jolly, Clemency Leshchiner, Ignaty Dentro, Stefan C. Gonzalez, Santiago Rosebrock, Daniel Mitchell, Thomas J. Rubanova, Yulia Anur, Pavana Yu, Kaixian Tarabichi, Maxime Deshwar, Amit Wintersinger, Jeff Kleinheinz, Kortine Vazquez-Garcia, Ignacio Haase, Kerstin Jerman, Lara Sengupta, Subhajit Macintyre, Geoff Malikic, Salem Donmez, Nilgun Livitz, Dimitri G. Cmero, Marek Demeulemeester, Jonas Schumacher, Steven Fan, Yu Yao, Xiaotong Lee, Juhee Schlesner, Matthias Boutros, Paul C. Bowtell, David D. Zhu, Hongtu Getz, Gad Imielinski, Marcin Beroukhim, Rameen Sahinalp, S. Cenk Ji, Yuan Peifer, Martin Markowetz, Florian Mustonen, Ville Yuan, Ke Wang, Wenyi Morris, Quaid D. Spellman, Paul T. Wedge, David C. Van Loo, Peter European Molecular Biology Laboratory European Bioinformatics Institute (EMBL-EBI) Cambridge UK European Molecular Biology Laboratory Genome Biology Unit Heidelberg Germany Wellcome Sanger Institute Cambridge UK Genome Biology Unit European Molecular Biology Laboratory (EMBL) Heidelberg Germany University of Ljubljana Ljubljana Slovenia The Francis Crick Institute London UK Big Data Institute University of Oxford Oxford UK Wellcome Sanger Institute Wellcome Genome Campus Hinxton UK Big Data Institute Li Ka Shing Centre University of Oxford Oxford UK University of Cambridge Cambridge UK Cambridge University Hospitals NHS Foundation Trust Cambridge UK Department of Applied Mathematics and Theoretical Physics Centre for Mathematical Sciences University of Cambridge Cambridge UK Department of Epidemiology and Biostatistics Memorial Sloan Kettering Cancer Center New York NY USA Department of Statistics Columbia University New York NY USA Department of Haematology University of Cambridge Cambridge UK University of Leuven Leuven Belgium Broad Institute of MIT and Harvard Cambridge MA USA Center for Cancer Research Massachusetts General Hospital Charlestown MA USA Department of Pathology Massachusetts General Hospital Boston MA USA Harvard Medical School Boston MA USA Center for Cancer Research Massachusetts General Hospital Boston MA USA Dana-Farber Cancer Institute Boston MA USA Department of Medical Oncology Dana-Farber Cancer Institute Boston MA USA Department of Cancer Biology Dana-Farber Cancer Institute Boston MA USA Oxford NIHR Biomedical Research Centre Oxford UK Oxford NIHR Biomedical Research Centre University of Oxford Oxford UK University of Toronto Toronto Ontario Canada Vector Institute Toronto Ontario Canada Vector Institute Toronto ON Canada Department of Computer Science University of Toronto Toronto ON Canada Ontario Institute for Cancer Research Toronto Ontario Canada University of California Los Angeles

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A task-oriented and parameterized (semi) autonomous navigation framework for the development of simulation systems

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Procedia computer science 2017年 112卷 534-543页

作者： Juliana R. Brondani Edison P. de Freitas Luis A.L. Silva Graduate Program in Electrical Engineering Federal University of Rio Grande do Sul Av. Paulo Gama 110 Porto Alegre 90040-060 Brazil Graduate Program in Computer Science Federal University of Santa Maria“ Av. Roraima 1000 Santa Maria 97105-900 Brazil

Agent behaviors in simulation systems are related to fundamental capabilities of realistically developing (semi) autonomous navigation actions. This is particularly important when dealing with the implementation of computer Generated Forces (CGFs) for simulation systems in tactical military training applications. Moreover, these systems take into consideration the particularities of the domain-specific simulation tasks and the numerous heterogeneous CGFs inserted on them in order to generate better knowledge and learning experience to simulation system users. Based on these reasons, this paper reviews recurrent navigation problems as to propose a task-oriented and parameterized (semi) autonomous navigation framework to deal with CGF navigation needs in military simulation. Combining global and local navigation techniques, and controlled transition between alternative degrees of navigation autonomy, the framework aims to overcome the challenges of implementing customizable CGF navigation behaviors and, at the same time, to allow interaction with both users and other simulation systems in distributed simulation settings. A case study is presented in which the proposed techniques are analyzed in a domain-specific simulation problem providing evidence of their suitability to address the studied military simulation problems.

关键词： Navigation problems task-oriented navigation semi-autonomous algorithms simulation systems

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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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Three-port converter based on the bidirectional Ćuk and the LC series-resonant half-bridge topologies for renewable energy applications

Three-port converter based on the bidirectional Ćuk and the...

引用

IEEE/IAS International Conference on Industry Applications (INDUSCON)

作者： Juliano Luiz dos Santos de Morais Roger Gules Graduate Program in Electrical and Computer Engineering — CPGEI UTFPR Curitiba Brazil

The development of a DC-DC three-port converter (TPC) is proposed in this paper. Through the combination of a bidirectional Ćuk converter and a high frequency transformer with a full-bridge (FB) rectifier circuit, two non-isolated energy ports and one isolated energy port are achieved. A LC series-resonant circuit is employed, resulting in soft-switching in the power switches. The bidirectional Cuk converter, controlled by pulse width modulation (PWM), and the tank resonant circuit, controlled by pulse frequency modulation (PFM) above the resonance frequency, allow two control variables for the topology. Furthermore, the power switches are shared for the operation of both circuits, reducing the number of active components. Voltage and current regulation are performed for applications with photovoltaic panel and bank of batteries. Operation modes, converter analysis and control strategy of the proposed TPC are presented. Experimental results are implemented to discuss the feasibility of the proposed TPC.

关键词： Inductors Capacitors Topology Batteries Resonant frequency RLC circuits Switches

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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

作者： A M H Pardede Lorena Perbina Br Sitepu Muhammad Zarlis Tulus Akbar Iskandar S Sriadhi Rosida Tiurma Manurung Nurintan Asyiah Siregar Ayu Esteka Sari Sri Yunawati M Mursyidah M Mursalin Nuning Kurniasih Citra Kurniawan Edy Winarno 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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Nanophotonic engineering of far-field thermal emitters

arXiv

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arXiv 2018年

作者： Baranov, Denis G. Xiao, Yuzhe Nechepurenko, Igor A. Krasnok, Alex Alù, Andrea Kats, Mikhail A. Department of Physics Chalmers University of Technology Gothenburg412 96 Sweden Department of Electrical and Computer Engineering University of Wisconsin-Madison WI United States Dukhov Research Institute of Automatics 22 Sushchevskaya Moscow127055 Russia Photonics Initiative Advanced Science Research Center City University of New York NY10031 United States Physics Program Graduate Center City University of New York NY10016 United States Department of Electrical Engineering City College of The City University of New York New York10031 United States Department of Materials Science and Engineering University of Wisconsin-Madison WI United States Department of Physics University of Wisconsin-Madison WI United States

Thermal emission is a ubiquitous and fundamental process by which all objects at non-zero temperatures radiate electromagnetic energy. This process is often presented to be incoherent in both space and time, resulting in broadband, omnidirectional light emission toward the far field, with a spectral density related to the emitter temperature by Planck’s law. Over the past two decades, there has been considerable progress in engineering the spectrum, directionality, polarization, and temporal response of thermally emitted light using nanostructured materials. This review summarizes the basic physics of thermal emission, lays out various nanophotonic approaches to engineer thermal-emission in the far field, and highlights several relevant applications, including energy harvesting, lighting, and radiative cooling. Copyright © 2018, The Authors. All rights reserved.

关键词： Spectral density

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Acoustic supercoupling in a zero-compressibility waveguide

arXiv

引用

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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