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Canadian Journal of electrical and computer engineering 2019年第3期42卷 163-172页

作者： Liang, Xiaodong Shabbir, Md. Nasmus Sakib Khan Khan, Nahidul Yan, Xiaodi Department of Electrical and Computer Engineering Memorial University of Newfoundland St. John'sNLA1B 3X5 Canada Energy Control Center Newfoundland and Labrador Hydro St. John'sNLA1B 4K7 Canada

In this paper, the measurement-based characteristic curves, reactive power-voltage ( Q-V ) curve and reactive power-active power-voltage ( Q-P-V ) curve, are developed for voltage stability and control at the point of interconnection (POI) between a wind power plant (WPP) and a utility grid. The procedure to obtain an effective Q-V curve using the supervisory control and data acquisition (SCADA) measurement data is proposed. The SCADA data used in this paper were recorded in 2016 at the POI of a 27-MW WPP currently in operation in Newfoundland and Labrador (NL), Canada. Each Q-V curve is created for a particular month using the SCADA data corresponding to a very narrowly defined active power range, so the active power is considered constant as the conventional Q-V curve concept. The MATLAB curve fitting toolbox is used to realize the most fit mathematical equations for Q-V and Q-P-V curves. The developed Q-V and Q-P-V curves can be used for the data-driven voltage control for WPPs;and the Q-V curves can also be used for the voltage stability evaluation. © 2003-2010 IEEE Canada.

关键词： Reactive power

How to Use the Internet Stock Message Board to Estimate the Dynamics of Stock Market 2nd

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How to Use the Internet Stock Message Board to Estimate the ...

2nd International Conference on Advanced Data and Information engineering, DaEng 2015

作者： Lee, Yun-Jung Cheon, Junseok Woo, Gyun Creative Human Resource Development Program for IT Convergence Pusan Nat’l University Busan609-735 Korea Republic of Department of Electrical and Computer Engineering Pusan Nat’l University Busan609-735 Korea Republic of Smart Control Center of LG Electronics Department of Electrical and Computer Engineering Pusan Nat’l University Busan609-735 Korea Republic of

ISBN: (纸本)9789811317972

In this paper, we analyze the correlation between the stock prices and the human interactions in Internet stock message board. To uncover this correlation, we analyzed the articles concerning with 380 target companies, members of S&P500. And we found that the strength of correlation between the article volume and the stock prices is relevant to the stock returns. Based on this statistics analysis, we proposed a method for recommending stock portfolio and tested the method using a simulated investment. According to the test result, the stock returns of our portfolio is about 1.41% per a month, which is about 0.42% point and 0.15% point higher than those of the S&P500 index and of the Markowitz’s efficient portfolio respectively. This result implies that the collective human behavior on Internet stock message board can be much helpful to understand the stock market and that the correlation between the stock prices and the collective human behavior can be used to invest in stocks. © Springer Nature Singapore Pte Ltd. 2019.

关键词： Financial markets

Localization transition induced by programmable disorder

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Physical Review B 2022年第13期105卷 134201-134201页

作者： Jaime L. C. da C. Filho Zoe Gonzalez Izquierdo Andreia Saguia Tameem Albash Itay Hen Marcelo S. Sarandy Instituto Federal do Pará - Campus Castanhal BR 316 Km 61 Saudade II 68740-970 Castanhal PA Brazil QuAIL NASA Ames Research Center Moffett Field California 94035 USA USRA Research Institute for Advanced Computer Science Mountain View California 94043 USA Instituto de Física Universidade Federal Fluminense Av. Gal. Milton Tavares de Souza s/n Gragoatá 24210-346 Niterói Rio de Janeiro Brazil Department of Electrical and Computer Engineering University of New Mexico Albuquerque New Mexico 87131 USA Department of Physics and Astronomy and Center for Quantum Information and Control CQuIC University of New Mexico Albuquerque New Mexico 87131 USA Department of Physics and Astronomy and Center for Quantum Information Science & Technology University of Southern California Los Angeles California 90089 USA Information Sciences Institute University of Southern California Marina del Rey California 90292 USA

We investigate the occurrence of many-body localization (MBL) on a spin-1/2 transverse-field Ising model defined on a Chimera connectivity graph with random exchange interactions and longitudinal fields. We observe a transition from an ergodic phase to a nonthermal phase for individual energy eigenstates induced by a critical disorder strength for the Ising parameters. Our result follows from the analysis of both the mean half-system block entanglement and the energy-level statistics. We identify the critical point associated with this transition using the maximum variance of the block entanglement over the disorder ensemble as a function of the disorder strength. The calculated energy density phase diagram shows the existence of a mobility edge in the energy spectrum. In terms of the energy-level statistics, the system changes from the Gaussian orthogonal ensemble for weak disorder to a Poisson distribution limit for strong randomness, which implies localization behavior. We then realize the time-independent disordered Ising Hamiltonian experimentally using a reverse annealing quench-pause-quench protocol on a D-wave 2000Q programmable quantum annealer. We characterize the transition from the thermal to the localized phase through magnetization measurements at the end of the annealing dynamics, and the results are compatible with our theoretical prediction for the critical point. However, the same behavior can be reproduced using a classical spin-vector Monte Carlo simulation, which suggests that genuine quantum signatures of the phase transition remain out of reach using this experimental platform and protocol.

关键词： Adiabatic quantum optimization Many-body localization Disordered systems Quantum spin models Annealing

Policy evaluation and seeking for multi-agent reinforcement learning via best response

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arXiv 2020年

作者： Yan, Rui Duan, Xiaoming Shi, Zongying Zhong, Yisheng Marden, Jason R. Bullo, Francesco Department of Automation Tsinghua University Beijing100084 China Mechanical Engineering Department Center of Control Dynamical Systems and Computation UC Santa BarbaraCA93106-5070 United States Department of Electrical and Computer Engineering UC Santa Barbara CA93106-5070 United States

This paper introduces two metrics (cycle-based and memory-based metrics), grounded on a dynamical game-theoretic solution concept called sink equilibrium, for the evaluation, ranking, and computation of policies in multi-agent learning. We adopt strict best response dynamics (SBRD) to model selfish behaviors at a meta-level for multi-agent reinforcement learning. Our approach can deal with dynamical cyclical behaviors (unlike approaches based on Nash equilibria and Elo ratings), and is more compatible with single-agent reinforcement learning than α-rank which relies on weakly better responses. We first consider settings where the difference between largest and second largest underlying metric has a known lower bound. With this knowledge we propose a class of perturbed SBRD with the following property: only policies with maximum metric are observed with nonzero probability for a broad class of stochastic games with finite memory. We then consider settings where the lower bound for the difference is unknown. For this setting, we propose a class of perturbed SBRD such that the metrics of the policies observed with nonzero probability differ from the optimal by any given tolerance. The proposed perturbed SBRD addresses the opponent-induced non-stationarity by fixing the strategies of others for the learning agent, and uses empirical game-theoretic analysis to estimate payoffs for each strategy profile obtained due to the perturbation. Copyright © 2020, The Authors. All rights reserved.

关键词： Game theory

Stable and Efficient Structures in Multigroup Network Formation

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arXiv 2020年

作者： Mohagheghi, Shadi Ma, Jingying Bullo, Francesco Department of Electrical and Computer Engineering Center for Control Dynamical Systems and Computation University of California at Santa Barbara Santa BarbaraCA93106-9560 United States School of Mathematics and Statistics Ningxia University Yinchuan750021 China

In this work we present a strategic network formation model predicting the emergence of multigroup structures. Individuals decide to form or remove links based on the benefits and costs those connections carry;we focus on bilateral consent for link formation. An exogenous system specifies the frequency of coordination issues arising among the groups. We are interested in structures that arise to resolve coordination issues and, specifically, structures in which groups are linked through bridging, redundant, and co-membership interconnections. We characterize the conditions under which certain structures are stable and study their efficiency as well as the convergence of formation dynamics. Copyright © 2020, The Authors. All rights reserved.

关键词： Game theory

Glassy Behavior and Anomalous Transport in Chimney Ladder Crystals Induced by Soft Optical Phonons

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arXiv 2025年

作者： Mandyam, Srinivas V. Dong, Weicen Yan, Xiaoxian Zhao, Binru Lin, Junfa Xia, Tianlong Zhao, Zhiying Chen, Xi Ma, Jie Xing, Hui Grosche, F. Malte Baggioli, Matteo Department of Physics Harvard University CambridgeMA02135 United States Wilczek Quantum Center School of Physics and Astronomy Shanghai Jiao Tong University Shanghai200240 China Shanghai Research Center for Quantum Sciences Shanghai201315 China Key Laboratory of Artificial Structures and Quantum Control School of Physics and Astronomy Shanghai Jiao Tong University Shanghai200240 China Shanghai Center for Complex Physics School of Physics and Astronomy Shanghai Jiao Tong University Shanghai China School of Physics Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices Renmin University of China Beijing100872 China Renmin University of China Beijing100872 China Laboratory for Neutron Scattering Renmin University of China Beijing100872 China State Key Laboratory of Structural Chemistry Fujian Institute of Research The Structure of Matter Chinese Academy of Sciences Fujian Fuzhou350002 China Department of Electrical and Computer Engineering University of California RiversideCA92521 United States Collaborative Innovation Center of Advanced Microstructures Jiangsu Nanjing210093 China Cavendish Laboratory University of Cambridge JJ Thomson Avenue CambridgeCB30HE United Kingdom

Nowotny chimney ladder (NCL) crystals present physical properties in between the contrasting paradigms of ideal crystal and amorphous solid, making them promising candidates for thermoelectric applications due to their inherently low thermal conductivity. Here, we report an extensive experimental characterization of the thermodynamic and thermoelectric transport properties of a large class of NCL materials, focusing on the intermetallic compound Ru2Sn3−δ. We show that the heat capacity of these NCL compounds exhibits a boson-peak-like glassy anomaly between 8 K and 14 K. By combining experimental measurements with density functional theory (DFT), we attribute its microscopic origin to extremely soft optical phonons that universally appear as a consequence of the chimney ladder sublattice structure. Additionally, the measured thermal conductivity and the thermoelectric response present distinct anomalous glass-like features that strongly correlate with the dynamics of the abundant soft optical phonons revealed by DFT. Our work demonstrates that soft modes in ordered crystals can induce glassy behavior, outlining a pathway to design metallic materials with low thermal conductivity and unique thermoelectric properties without the need for disorder or strong electronic correlations. © 2025, CC BY.

关键词： Glass

Observation of Integer and Fractional Quantum Anomalous Hall Effects in Twisted Bilayer MoTe2

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Physical Review X 2023年第3期13卷 031037-031037页

作者： Fan Xu Zheng Sun Tongtong Jia Chang Liu Cheng Xu Chushan Li Yu Gu Kenji Watanabe Takashi Taniguchi Bingbing Tong Jinfeng Jia Zhiwen Shi Shengwei Jiang Yang Zhang Xiaoxue Liu Tingxin Li Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education) Shenyang National Laboratory for Materials Science School of Physics and Astronomy Shanghai Jiao Tong University Shanghai 200240 China Tsung-Dao Lee Institute Shanghai Jiao Tong University Shanghai 201210 China Department of Physics and Astronomy University of Tennessee Knoxville Tennessee 37996 USA State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics Tsinghua University 100084 Beijing China Research Center for Electronic and Optical Materials National Institute for Materials Science 1-1 Namiki Tsukuba 305-0044 Japan Research Center for Materials Nanoarchitectonics National Institute for Materials Science 1-1 Namiki Tsukuba 305-0044 Japan Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences Beijing 100190 China Hefei National Laboratory Hefei 230088 China Min H. Kao Department of Electrical Engineering and Computer Science University of Tennessee Knoxville Tennessee 37996 USA

The interplay between strong correlations and topology can lead to the emergence of intriguing quantum states of matter. One well-known example is the fractional quantum Hall effect, where exotic electron fluids with fractionally charged excitations form in partially filled Landau levels. The emergence of topological moiré flat bands provides exciting opportunities to realize the lattice analogs of both the integer and fractional quantum Hall effects without the need for an external magnetic field. These effects are known as the integer and fractional quantum anomalous Hall (IQAH and FQAH) effects. Here, we present direct transport evidence of the existence of both IQAH and FQAH effects in small-angle-twisted bilayer MoTe2. At zero magnetic field, we observe well-quantized Hall resistance of h/e2 around moiré filling factor ν=−1 (corresponding to one hole per moiré unit cell), and nearly quantized Hall resistance of 3h/2e2 around ν=−2/3, respectively. Concomitantly, the longitudinal resistance exhibits distinct minima around ν=−1 and −2/3. The application of an electric field induces topological quantum phase transition from the IQAH state to a charge transfer insulator at ν=−1, and from the FQAH state to a topologically trivial correlated insulator, further transitioning to a metallic state at ν=−2/3. Our study paves the way for the investigation of fractionally charged excitations and anyonic statistics at zero magnetic field based on semiconductor moiré materials.

关键词： Magnetism Phase transitions Topological materials

An IoT Edge Computing System Architecture and its Application

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An IoT Edge Computing System Architecture and its Applicatio...

2020 IEEE International Conference on Networking, Sensing and control, ICNSC 2020

作者： Chen, Shichao Li, Qijie Zhang, Hua Zhu, Fenghua Xiong, Gang Tang, Ying Macau University of Science and Technology State Key Laboratory for Management and Control of Complex Systems Institute of Automation Chinese Academy of Sciences China Beijing University of Technology State Key Laboratory for Management and Control of Complex Systems Institute of Automation Chinese Academy of Sciences Beijing China Beijing Aerospace Smart Manufacturing Technology Development Co. Ltd Platform Research and Development Department Beijing China State Key Laboratory for Management and Control of Complex Systems Institute of Automation Chinese Academy of Sciences Beijing China Engineering Research Center of Intelligent Systems and Technology Institute of Automation Cloud Computing Center Chinese Academy of Sciences Beijing China Rowan University Department of Electrical and Computer Engineering GlassboroNJ United States Institute of Smart Education Qingdao Academy of Intelligent Industries Qingdao China

ISBN: (纸本)9781728168531

As the number of devices connected to the Internet of things (IoT) surges, the amount of data explodes. Therefore it not only increases the bandwidth load of data transmission but also aggravates the computing and storage load of a cloud platform. At the same time, the traditional computing paradigm centered on cloud computing cannot meet the real-time requirements in many application scenarios. The emergence of edge computing can solve the problems of realtime data processing and network bandwidth occupation in the current IoT scene. In this paper, according to the characteristics of IoT, such as fragmented data, heterogeneous network, and limited energy consumption, the architecture of an IoT edge computing system is constructed to suit better an IoT scene. In addition, the application of edge computing key technologies such as virtualization, edge intelligence, computing offload, collaborative scheduling and micro-services in resource-constrained IoT scenarios is analyzed in detail. Finally, the functions and application of energy consumption monitoring and optimization to a central air-conditioning system are analyzed and summarized, which is a typical application of edge computing in the context of the IoT. © 2020 IEEE.

关键词： Edge computing

Robust beamforming design for covert communications

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arXiv 2021年

作者： Ma, Shuai Zhang, Yunqi Li, Hang Lu, Songtao Al-Dhahir, Naofal Zhang, Sha Li, Shiyin School of Information and Control Engineering China University of Mining and Technology Xuzhou221116 China National Mobile Communications Research Laboratory Southeast University Nanjing210096 China Shenzhen Research Institute of Big Data Shenzhen Guangdong518172 China IBM Thomas J. Watson Research Center Yorktown HeightsNY10598 United States Electrical and Computer Engineering Department University of Texas at Dallas DallasTX75080 United States Shenzhen Institute of Radio Testing and Tech Shenzhen518000 China

In this paper, we consider a common unicast beamforming network where Alice utilizes the communication to Carol as a cover and covertly transmits a message to Bob without being recognized by Willie. We investigate the beamformer design of Alice to maximize the covert rate to Bob when Alice has either perfect or imperfect knowledge about Willie’s channel state information (WCSI). For the perfect WCSI case, the problem is formulated under the perfect covert constraint, and we develop a covert beamformer by applying semidefinite relaxation and the bisection method. Then, to reduce the computational complexity, we further propose a zero-forcing beamformer design with a single iteration processing. For the case of the imperfect WCSI, the robust beamformer is developed based on a relaxation and restriction approach by utilizing the property of Kullback-Leibler divergence. Furthermore, we derive the optimal decision threshold of Willie, and analyze the false alarm and the missed detection probabilities in this case. Finally, the performance of the proposed beamformer designs is evaluated through numerical experiments. © 2021, CC BY.

关键词： Channel state information

Accelerated Multi-Agent Optimization Method over Stochastic Networks

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Accelerated Multi-Agent Optimization Method over Stochastic ...

IEEE Conference on Decision and control

作者： Wicak Ananduta Carlos Ocampo-Martinez Angelia Nedić Delft Center of Systems and Control (DCSC) TU Delft the Netherlands Institut de Robòtica i Informàtica Industrial (CSIC-UPC) Barcelona Spain School of Electrical Computer and Energy Engineering Arizona State University USA

ISBN: (数字)9781728174471

ISBN: (纸本)9781728174488

We propose a distributed method to solve a multi-agent optimization problem with strongly convex cost function and equality coupling constraints. The method is based on Nesterov's accelerated gradient approach and works over stochastically time-varying communication networks. We consider the standard assumptions of Nesterov's method and show that the sequence of the expected dual values converge toward the optimal value with the rate of O(1/k 2 ). Furthermore, we provide a simulation study of solving an optimal power flow problem with a well-known benchmark case.

关键词： Acceleration Communication networks Couplings Gradient methods Cost function Convergence Stochastic processes