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DC Microgrids under Denial of Service Attacks: Feasibility and Stability Issues 12

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DC Microgrids under Denial of Service Attacks: Feasibility a...

12th Annual IEEE Energy Conversion Congress and Exposition, ECCE 2020

作者： Liu, Jianzhe Cui, Bai Chen, Bo Lu, Xiaonan Qiu, Feng Mazumder, Sudip Argonne National Laboratory Energy Systems Division Lemont United States National Renewable Energy Laboratory Power Systems Engr. Center Golden United States Temple University College of Engineering Philadelphia United States University of Illinois at Chicago Dept. Electrical and Computer Engr. Chicago United States

ISBN: (数字)9781728158266

ISBN: (纸本)9781728158266

Distributed control has been extensively studied for a DC microgrid to coordinate multiple grid assets where each asset can generate its own control decisions based on communications within its neighborhood. Nevertheless, such a control strategy usually has a strong dependence on active information exchange and needs to always maintain a pre-determined communication graph. This makes it vulnerable to cyber attacks, especially denial of service (DoS) attacks that block communication channels that effectively change the communication graph. In this paper, we study two potential impacts of DoS attacks: the inability to maintain steady-state and dynamical generation-demand balance, i.e. the feasibility and stability issues. We develop a mathematical model to describe the cyber-induced system steady-state and dynamical performance. The model reveals the impacts of DoS attacks and enables formal analysis. Case studies are shown to verify the proposed work. © 2020 IEEE.

关键词： Denial-of-service attack

High-specific-power flexible transition metal dichalcogenide solar cells

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arXiv 2021年

作者： Nazif, Koosha Nassiri Daus, Alwin Hong, Jiho Lee, Nayeun Vaziri, Sam Kumar, Aravindh Nitta, Frederick Chen, Michelle Kananian, Siavash Islam, Raisul Kim, Kwan-Ho Park, Jin-Hong Poon, Ada Brongersma, Mark L. Pop, Eric Saraswat, Krishna C. Dept. of Electrical Engineering Stanford University StanfordCA94305 United States Geballe Laboratory for Advanced Materials Stanford University StanfordCA94305 United States Dept. of Materials Science and Engineering Stanford University StanfordCA94305 United States Dept. of Electrical and Computer Engineering Sungkyunkwan University Suwon16419 Korea Republic of Dept. of Electrical and Systems Engineering University of Pennsylvania PhiladelphiaPA19104 United States Sungkyunkwan University Suwon16419 Korea Republic of Dept. of Applied Physics Stanford University StanfordCA94305 United States

Semiconducting transition metal dichalcogenides (TMDs) are promising for flexible high-specific-power photovoltaics due to their ultrahigh optical absorption coefficients, desirable band gaps and self-passivated surfaces. However, challenges such as Fermi-level pinning at the metal contact-TMD interface and the inapplicability of traditional doping schemes have prevented most TMD solar cells from exceeding 2% power conversion efficiency (PCE). In addition, fabrication on flexible substrates tends to contaminate or damage TMD interfaces, further reducing performance. Here, we address these fundamental issues by employing: 1) transparent graphene contacts to mitigate Fermi-level pinning, 2) MoOx capping for doping, passivation and anti-reflection, and 3) a clean, non-damaging direct transfer method to realize devices on lightweight flexible polyimide substrates. These lead to record PCE of 5.1% and record specific power of 4.4 W g-1 for flexible TMD (WSe2) solar cells, the latter on par with prevailing thin-film solar technologies cadmium telluride, copper indium gallium selenide, amorphous silicon and III-Vs. We further project that TMD solar cells could achieve specific power up to 46 W g-1, creating unprecedented opportunities in a broad range of industries from aerospace to wearable and implantable electronics. Copyright © 2021, The Authors. All rights reserved.

关键词： Transition metals

Speak with signs: Active learning platform for Greek sign language, English sign language, and their translation

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arXiv 2020年

作者： Papatsimouli, Maria Lazaridis, Lazaros Kollias, Konstantinos-Filippos Skordas, Ioannis Fragulis, George F. Laboratory of Robotics Embedded and Integrated Systems Dept. of Electrical and Computer Engineering University of Western Macedonia Hellas Greece

Sign Language is used to facilitate the communication between Deaf and non-Deaf people. It uses signs-words with basic structural elements such as handshape, parts of face, body or space, and the orientation of the fingers-palm. Sign Languages vary from people to people and from country to country and evolve as spoken languages. In the current study, an application which aims at Greek Sign Language and English Sign Language learning by hard of hearing people and talking people, has been developed. The application includes grouped signs in alphabetical order. The user can find Greek Sign Language signs, English sign language signs and translate from Greek sign language to English sign language. The written word of each sign, and the corresponding meaning are displayed. In addition, the sound is activated in order to enable users with partial hearing loss to hear the pronunciation of each word. The user is also provided with various tasks in order to enable an interaction of the knowledge acquired by the user. This interaction is offered mainly by multiple-choice tasks, incorporating text or video. The current application is not a simple sign language dictionary as it provides the interactive participation of users. It is a platform for Greek and English sign language active learning. Copyright © 2020, The Authors. All rights reserved.

关键词： Audition

Machine learning identifies scale-free properties in disordered materials

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arXiv 2020年

作者： Yu, Sunkyu Piao, Xianji Park, Namkyoo Photonic Systems Laboratory Dept. of Electrical and Computer Engineering Seoul National University Seoul08826 Korea Republic of

The vast amount of design freedom in disordered systems expands the parameter space for signal processing, allowing for unique signal flows that are distinguished from those in regular systems. However, this large degree of freedom has hindered the deterministic design of disordered systems for target functionalities. Here, we employ a machine learning (ML) approach for predicting and designing wave-matter interactions in disordered structures, thereby identifying scale-free properties for waves. To abstract and map the features of wave behaviours and disordered structures, we develop disorder-to-localization and localization-to-disorder convolutional neural networks (CNNs). Each CNN enables the instantaneous prediction of wave localization in disordered structures and the instantaneous generation of disordered structures from given localizations. We demonstrate that CNN-generated disordered structures have scale-free properties with heavy tails and hub atoms, which exhibit an increase of multiple orders of magnitude in robustness to accidental defects, such as material or structural imperfection. Our results verify the critical role of ML network structures in determining ML-generated real-space structures, which can be used in the design of defect-immune and efficiently tunable devices. Copyright © 2020, The Authors. All rights reserved.

关键词： Machine learning

Dynamic Resilient Graph Games for State-Dependent Jamming Attacks Analysis on Multi-Agent systems

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IFAC-PapersOnLine 2020年第2期53卷 3421-3426页

作者： Yurid Nugraha Ahmet Cetinkaya Tomohisa Hayakawa Hideaki Ishii Quanyan Zhu Dept. of Systems and Control Engineering Tokyo Institute of Technology Tokyo 152-8552 Japan Information Systems Architecture Science Research Division National Institute of Informatics Tokyo 101-8430 Japan Dept. of Computer Science Tokyo Insitute of Technology Yokohama 226-8502 Japan Dept. of Electrical and Computer Engineering New York University Brooklyn NY 11201 USA

A cybersecurity problem for a multi-agent consensus problem is investigated through a dynamic game formulation. Specifically, we consider a game repeatedly played between a jamming attacker and a defender. The attacker attempts to jam the links between a number of agents to delay their consensus. On the other hand, the defender tries to maintain the connection between agents by attempting to recover some of the jammed links with the goal of achieving faster consensus. In each game, the players decide which links to attack/recover and for how long to continue doing so based on a Lyapunov-like function representing the largest difference between the states of the agents. We analyze the subgame perfect equilibrium of the game and obtain an upper bound of the consensus time that is influenced by the strategies of the players. The results are illustrated with a numerical example.

关键词： Multi-agent systems Consensus problem Game theory Cybersecurity

VGAI: A vision-based decentralized controller learning framework for robot swarms

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arXiv 2020年

作者： Hu, Ting-Kuei Gama, Fernando Wang, Zhangyang Ribeiro, Alejandro Sadler, Brian M. Dept. of Computer Science and Engineering Texas A&M University United States Dept. of Electrical and Systems Engineering University of Pennsylvania United States Army Research Laboratory United States

Despite the popularity of decentralized controller learning, very few successes have been demonstrated on learning to control large robot swarms using raw visual observations. To fill in this gap, we present Vision-based Graph Aggregation and Inference (VGAI), a decentralized learning-to-control framework that directly maps raw visual observations to agent actions, aided by sparse local communication among only neighboring agents. Our framework is implemented by an innovative cascade of convolutional neural networks (CNNs) and one graph neural network (GNN), addressing agent-level visual perception and feature learning, as well as swarm-level local information aggregation and agent action inference, respectively. Using the application example of drone flocking, we show that VGAI yields comparable or more competitive performance with other decentralized controllers, and even the centralized controller that learns from global information. Especially, it shows substantial scalability to learn over large swarms (e.g., 50 agents), thanks to the integration between visual perception and local communication. Copyright © 2020, The Authors. All rights reserved.

关键词： Vision

COMPARISON OF OPTIMAL POWER FLOW FORMULATIONS IN ACTIVE DISTRIBUTION GRIDS

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COMPARISON OF OPTIMAL POWER FLOW FORMULATIONS IN ACTIVE DIST...

The 12th Mediterranean Conference on Power Generation, Transmission, Distribution and Energy Conversion (MEDPOWER 2020)

作者： C. Mylonas S. Karagiannopoulos P. Aristidou D. Shchetinin G. Hug Power Systems Laboratory ETH Zurich 8092 Zurich Switzerland Dept. of Electrical Engineering Computer Engineering & Informatics Cyprus University of Technology 3036 Limassol Cyprus ABB Corporate Research Center 5405 Baden Switzerland

Active Distribution Networks (DNs) are expected to host an increasing number of Distributed Generators (DGs) and other Distributed Energy Resources (DERs), offering new flexible sources and enabling the provision of ancillary services to system operators. Centralized DER controls that use Optimal Power Flow (OPF) methods necessitate tractable and scalable computational tools that can handle large DNs with satisfactory performance. In this paper, we compare an iterative OPF method against the standard exact AC OPF calculations in terms of the computational effort and solution quality. Furthermore, we highlight the suitability of the selected formulation to offer voltage support (VS) as an ancillary service to the transmission network. The results are demonstrated using a combination of a medium and low voltage grid, and show that tractable OPF formulations can unlock financial business cases for DNs that can actively participate in VS schemes.

关键词： distributed power generation distribution networks load flow power grids iterative methods centralised control

An ARQ-Based Cooperative Relaying Scheme for 5G IoT Slice

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An ARQ-Based Cooperative Relaying Scheme for 5G IoT Slice

2019 IEEE Global Conference on Internet of Things, GCIoT 2019

作者： Otaru, Musa Ajiya, Mohammed Adinoyi, Abdulkareem Aljlayl, Mohammed Yanikomeroglu, Halim Telecommunications Services Nigerian Communications Satellite Ltd Abuja Nigeria Bayero University Department of Electrical Engineering Kano Nigeria Technology Enterprise Architecture Saudi Telecommunications Company Saudi Arabia Carleton University Dept. of Systems and Computer Engineering Ottawa Canada

ISBN: (纸本)9781728148731

We introduce a new twist to the classical automatic repeat request (ARQ)-based cooperative relaying scheme. Here, we target a 5G slice for offering internet-of-things (IoT)-inspired services. In this 5G application segment (e.g., utility or smart metering), utility sensors or devices are expected to last for decades and, operate on tight power budgets, and the system can tolerate periodic stops to check the fidelity of previous transmissions. For this scenario, we employ a service provider-deployed relay that alleviates the IoT devices of their communication burdens. The source transmits for a certain time window or period without requiring acknowledgments (ACK) from the destination. At the end of this window, the destination sends an ACK. If negative, the relay is expected to assist. Thus, the relay transmits only intermittently, in either one transmission time slot or a few time slots, using a suitably chosen higherorder modulation constellation. If no error occurs, the source continues its transmission. The numerical results show that with just a few antennas at the relay, the new scheme provides both a reduction in the number of ARQ transmissions and a superior probability of bit error compared with a reference scheme. We adopt the two-parameter Weibull fading model to evaluate the performance of the proposed scheme. © 2019 IEEE.

关键词： Internet of things

Post-2000 Nonlinear Optical Materials and Measurements: Data Tables and Best Practices

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arXiv 2023年

作者： Vermeulen, Nathalie Espinosa, Daniel Ball, Adam Ballato, John Boucaud, Philippe Boudebs, Georges Campos, Cecília L.A.V. Dragic, Peter Gomes, Anderson S.L. Huttunen, Mikko J. Kinsey, Nathaniel Mildren, Rich Neshev, Dragomir Padilha, Lázaro A. Pu, Minhao Secondo, Ray Tokunaga, Eiji Turchinovich, Dmitry Yan, Jingshi Yvind, Kresten Dolgaleva, Ksenia Van Stryland, Eric W. Brussels Photonics B-PHOT Department of Applied Physics and Photonics IR-TONA Vrije Universiteit Brussel Pleinlaan 2 Brussel1050 Belgium School of Electrical Engineering and Computer Science University of Ottawa OttawaONK1N 6N5 Canada Dept. Of Electrical & Computer Engineering Virginia Commonwealth University RichmondVA23284 United States Dept of Materials Science and Engineering Clemson University ClemsonSC29634 United States Université Côte d’Azur CNRS CRHEA Rue Bernard Grégory Sophia-Antipolis06905 France Univ Angers LPHIA SFR MATRIX AngersF-49000 France Departamento de Física Universidade Federal de Pernambuco PE Recife50670-901 Brazil Dept. Of Electrical & Computer Engineering University of Illinois at Urbana-Champaign UrbanaIL61801 United States Tampere University Photonics Laboratory Physics Unit TampereFI-33014 Finland MQ Photonics Research Centre Macquarie University NSW2109 Australia ARC Centre of Excellence for Transformative Meta-Optical Systems TMOS Department of Electronic Materials Engineering Research School of Physics Australian National University CanberraACT2601 Australia Instituto de Fisica "Gleb Wataghin" Universidade Estadual de Campinas Campinas Sao Paulo13083-970 Brazil Department of Electrical and Photonics engineering Technical University of Denmark Kgs. LyngbyDK-2800 Denmark Department of Physics Faculty of Science Tokyo University of Science 1-3 Kagurazaka Shinjuku-ku Tokyo162-8601 Japan Fakultät für Physik Universität Bielefeld Universitätsstr. 25 Bielefeld33615 Germany CREOL The College of Optics and Photonics University of Central Florida OrlandoFL United States

In its 60 years of existence, the field of nonlinear optics has gained momentum especially over the past two decades thanks to major breakthroughs in material science and technology. In this article, we present a new set of data tables listing nonlinear-optical properties for different material categories as reported in the literature since 2000. The papers included in the data tables are representative experimental works on bulk materials, solvents, 0D-1D-2D materials, metamaterials, fiber waveguiding materials, on-chip waveguiding materials, hybrid waveguiding systems, and materials suitable for nonlinear optics at THz frequencies. In addition to the data tables, we also provide best practices for performing and reporting nonlinear-optical experiments. These best practices underpin the selection process that was used for including papers in the tables. While the tables indeed show strong advancements in the field over the past two decades, we encourage the nonlinear-optics community to implement the identified best practices in future works. This will allow a more adequate comparison, interpretation and use of the published parameters, and as such further stimulate the overall progress in nonlinear-optical science and applications. © 2023, CC BY.

关键词： Nonlinear optics