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A Note on Self-Accelerating Olver and Olver-Gauss Beams

Optics and Photonics Journal 2019年第1期9卷 1-7页

作者： Ioannis M. Besieris Amr M. Shaarawi bradley Davis The bradley department of electrical and computer engineering Virginia Polytechnic Institute and State University Blacksburg VA USA department of Physics The American University in Cairo New Cairo Egypt Ted and Karyn Hume Center for National Security and technology Virginia Polytechnic Institute and State University Blacksburg VA USA

The recent introduction by Belafhal et al. [Opt. and Photon. J. 5, 234-246 (2015)] of mth-order Olver beams as a novel class of self-accelerating nondiffracting solutions to the paraxial equation is a direct contradiction to the seminal work of Berry and Balazs who determined that the infinite-energy Airy wave packet is the only accelerating nondiffracting solution to the (1 + 1)D Schrödinger equation. It is shown in this note that the work of Belafhal et al. is valid only for m=0, which coincides with the Airy solution.

关键词： Nondiffracting Waves Nonlinearly Self-Bending Beams Airy Beam Accelerating Olver and Olver-Gauss Beams

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Dynamic Intermittent Suboptimal Control: Performance Quantification and Comparisons

Dynamic Intermittent Suboptimal Control: Performance Quantif...

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第37届中国控制会议

作者： Yongliang Yang Kyriakos G.Vamvoudakis Hamidreza Modares Dawei Ding Yixin Yin Donald C.Wunsch School of Automation and electrical engineering University of Science and Technology Beijing Kevin T.Crofton department of Aerospace and Ocean engineering Virginia Tech department of electrical and computer engineering Missouri University of Science and Technology

This paper presents a novel intermittent suboptimal event-triggered controller design for continuous-time nonlinear systems. The stability of the equilibrium point of the closed-loop system, and the performances are analyzed and quantified theoretically. It is proven that the static and the dynamic event-triggered suboptimal controllers have a known degree of suboptimality compared to the conventional optimal control policy. In order to generate dynamic event-triggering framework, we introduce an internal dynamical system. Moreover, the Zeno behavior is excluded. Finally, a simulation example is conducted to show the effectiveness of the proposed intermittent mechanisms.

关键词： Event-triggered control performance analysis optimal control dynamic triggering condition

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Formation of polar ionospheric tongue of ionization during minor geomagnetic disturbed conditions

Formation of polar ionospheric tongue of ionization during m...

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中国科学院地质与地球物理研究所2015年度（第15届）学术年会

作者： Jing Liu Takuji Nakamura Libo Liu Wenbin Wang Nanan Balan Takanori Nishiyama Marc R.Hairston E.G.Thomas Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of Sciences High Altitude Observatory National Center for Atmospheric Research National Institute of Polar Research Center for Space Sciences University of Texas at Dallas bradley department of electrical and computer engineering Virginia Tech

Previous investigations of ionospheric storm-enhanced density(SED) and tongue of ionization(TOI)focused mostly on the behavior of TOI during intense geomagnetic *** attention has been paid to the spatial and temporal variations of TOI during weak to moderate geomagnetic disturbed *** this paper we investigate the source and development of TOI during a moderate geomagnetic storm on 14 October ***-instrumental observations including GPS total electron content(TEC),Defense Meteorological Satellite Program(DMSP) in situ measured total ion concentration and ion drift velocity,Super DARN measured polar ion convection patterns,and electron density profiles from the Poker Flat Incoherent Scatter Radar(PFISR) have been utilized in the current *** TEC maps show salient TOI structures persisting for about 5 h over high latitudes of North America on 14 October 2012 in the later recovery phase of the storm when the magnitudes of IMF By and Bz were less than 5 n *** PFISR electron density profiles indicate that the extra ionization for TEC enhancements mainly occurred in the topside ionosphere with no obvious changes in the bottomside ionosphere and vertical plasma ***,there were no signatures of penetration electric fields in the equatorial electrojet data and upward ion drifts at high *** the same time,strong subauroral polarization streams with ion drift speeds exceeding 2.5 km/s carried sunward fluxes and migrated toward lower latitudes for about 5° based on the DMSP cross-track drift *** on those measurements,we postulate that the combined effects of initial build-up of ionization at midlatitudes through daytime production of ionization and equatorward(or less poleward than normal daytime) neutral wind reducing downward diffusion along the inclined filed lines,and an expanded polar ion convection pattern and its associated horizontal plasma transport are important in the formation of the TOI.

关键词： Appearance of SED/TOI structures in the geomagnetic storm late recovery phase UT dependency of the SED/TOI strength TEC enhancements mainly occurred in the topside ionosphere

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极端灾害状态下配电网的应变能力

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供用电 2019年第7期36卷 35-43页

作者：莫可非 LIU Chen-Ching 许寅 School of electrical engineering and computer Science Washington State UniversityPullman WA 99164美国 The bradley department of electrical and computer engineering Virginia TechBlacksburg VA 24061美国北京交通大学电气工程学院北京100044

在发生极端灾害时,利用分布式电源、储能以及微电网等本地电源快速恢复配电网中的关键负荷可有效提升配电网的应变能力。文章详细介绍了电力系统“应变能力(resilience)”的基本概念、内涵及评价指标,分析了配电网应变能力的研究需求与... 详细信息

在发生极端灾害时,利用分布式电源、储能以及微电网等本地电源快速恢复配电网中的关键负荷可有效提升配电网的应变能力。文章详细介绍了电力系统“应变能力(resilience)”的基本概念、内涵及评价指标,分析了配电网应变能力的研究需求与提升手段,并提出了利用微电网实现配电网关键负荷供电恢复的方法。在此基础上,针对美国华盛顿州立大学(WSU)微电网、西北太平洋国家实验室(PNNL)4馈线1069节点配电网案例进行了分析与研究。分析结果表明,极端灾害场景下将微电网作为紧急电源可有效减小关键负荷的断电时间,从而提升配电网的应变能力;分布式电源的暂态特性对于供电恢复策略的可行性有较大影响,在制定供电恢复策略时应考虑。最后对配电网应变能力研究进行了展望。

关键词：配电网应变能力微电网极端灾害供电恢复

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A Robust Optical Encryption Method for Three-Dimensional Object Based on the Fresnel Transform

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Optics and Photonics Journal 2015年第11期5卷 313-319页

作者： Yinghong Liu Weimin Jin Xin Yang Di Wu Hongbo Zhang Institute of Information Optics Zhejiang Normal University Jinhua China Key Laboratory of Optical Information Detecting and Display technology in Zhejiang Province Jinhua China Institute of Information Optics engineering Soochow University Suzhou China department of electrical and computer engineering Virginia Tech Biacksburg VA USA

An optical encryption of three-dimensional (3D) object with digital holography was implemented. In the process of encryption, two holograms involved recording key information and 3D object were obtained. In the process of decryption, the 3D object was reconstructed from the two holograms by extracting the object and key information, followed by multiplication of the two holograms and inverse Fresnel transform numerically. The robustness of the method was also tested for different occlusions attacks and Gaussian noises. The results showed that the method was able to encrypt and decrypt the 3D object while being robust under different occlusions attacks and Gaussian noises.

关键词： Optical Encryption Three-Dimensional Object Digital Holography Fresnel Diffraction

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technical cross-fertilization between terrestrial microgrids and ship power systems

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Journal of Modern Power Systems and Clean Energy 2016年第2期4卷 161-179页

作者： Robert E.HEBNER Fabian M.URIARTE Alexis KWASINSKI Angelo L.GATTOZZI Hunter B.ESTES Asif ANWAR Pietro CAIROLI Roger A.DOUGAL Xianyong FENG Hung-Ming CHOU Laurence J.THOMAS Manisa PIPATTANASOMPORN Saifur RAHMAN Farid KATIRAEI Michael STEURER M.Omar FARUQUE Mario A.RIOS Gustavo A.RAMOS Mirrasoul J.MOUSAVI Timothy J.MCCOY Center for Electromechanics The University of Texas at AustinAustinTXUSA department of electrical and computer engineering University of PittsburghPittsburghPAUSA University of South Carolina ColumbiaSCUSA ABB Inc. RaleighNCUSA Texas A&M University College StationTXUSA Lauren Engineers and Constructors Inc.AbileneTXUSA virginia tech’s Advanced Research Institute ArlingtonVAUSA Quanta technology Inc.RaleighNCUSA Center for Advanced Power Systems Florida State UniversityTallahasseeFLUSA Universidad de los Andes Bogota´Colombia McCoy Consulting LLCMontrossVAUSA

Aspects of terrestrial microgrids and ship power systems are *** work exposes a variety of technical synergies from these two power systems to effectively advance their *** their overlap allows congruent efforts to target both systems;understanding their differences hinders conflict and redundancy in early-stage *** paper concludes by highlighting how an understanding of both systems can reduce the investment in research resources.

关键词： Microgrid Power systems Ship power systems

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Direct Observations of the Evolution of Polar Cap Ionization Patches

Direct Observations of the Evolution of Polar Cap Ionization...

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中国空间科学学会空间物理学专业委员会第十五届全国日地空间物理学研讨会

作者： Qing-He Zhang Bei-Chen Zhang Michael Lockwood Hong-Qiao Hu Jφran Moen Qing-He Zhang Bei-Chen Zhang Michael Lockwood Hong-Qiao Hu Jφran Moen John M.Ruohoniemi Evan G.Thomas Shun-Rong Zhang Hui-Gen Yang Rui-Yuan Liu Kathryn A.McWilliams Joseph.B.H.Baker SOA Key Laboratory for Polar Science Polar Research Institute of China department of Meteorology University of ReadingEarley GateP.O.Box 243RG6 6BBUK department of Physics University of OsloBlindernOsloNorway bradley department of electrical & computer engineering Virginia TechBlacksburgVirginiaUSA MIT Haystack Observatory WestfordMA 01886USA Institute of Space and Atmospheric Studies University of SaskatchewanSaskatoonSaskatchewanCanada

Patches of ionization are common in the polar ionosphere where their motion and associated density gradients give variable disturbances to High Frequency(HF)radio communications,over-the-horizon radar location errors,and disruption and errors to satellite navigation and *** formation and evolution are poorly understood,particularly under disturbed space weather *** report direct observations of the full evolution of patches during a geomagnetic storm,including formation,polar cap entry,transpolar evolution,polar cap exit,and sunward return *** observations show that modulation of nightside reconnection in the substorm cycle of the magnetosphere helps form the gaps between patches where steady convection would give a"tongue"of ionization(TOI).

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The joint automated repository for various integrated simulations (JARVIS) for data-driven materials design

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npj Computational Materials 2020年第1期6卷 234-246页

作者： Kamal Choudhary Kevin F.Garrity Andrew C.E.Reid Brian DeCost Adam J.Biacchi Angela R.Hight Walker Zachary Trautt Jason Hattrick-Simpers A.Gilad Kusne Andrea Centrone Albert Davydov Jie Jiang Ruth Pachter Gowoon Cheon Evan Reed Ankit Agrawal Xiaofeng Qian Vinit Sharma Houlong Zhuang Sergei V.Kalinin Bobby G.Sumpter Ghanshyam Pilania Pinar Acar Subhasish Mandal Kristjan Haule David Vanderbilt Karin Rabe Francesca Tavazza Materials Measurement Laboratory National Institute of Standards and TechnologyGaithersburgMD 20899USA Theiss Research La JollaCA 92037USA department of Chemistry and Biochemistry University of MarylandCollege ParkMD 20742USA Physical Measurement Laboratory National Institute of Standards and TechnologyGaithersburgMD 20899USA Materials and Manufacturing Directorate Air Force Research LaboratoryWright–Patterson Air Force BaseDaytonOH 45433USA department of Materials Science and engineering Stanford UniversityStanfordCA 94305USA department of electrical and computer engineering Northwestern UniversityEvanstonIL 60208USA department of Materials Science and engineering Texas A&M UniversityTexasTX 77843USA Joint Institute for Computational Sciences University of TennesseeKnoxvilleTN 37996USA National Institute for Computational Sciences Oak Ridge National LaboratoryOak RidgeTN 37831USA School for engineering of Matter Transport and Energy Arizona State UniversityTempeAZ 85287USA Center for Nanophase Materials Sciences Oak Ridge National LaboratoryOak RidgeTN 37831USA Materials Science and technology Division Los Alamos National LabLos AlamosNM 87545USA department of Mechanical engineering Virginia TechBlacksburgVA 24061USA department of Physics and Astronomy Rutgers UniversityPiscatawayNJ 08901USA

The Joint Automated Repository for Various Integrated Simulations(JARVIS)is an integrated infrastructure to accelerate materials discovery and design using density functional theory(DFT),classical force-fields(FF),and machine learning(ML)*** is motivated by the Materials Genome Initiative(MGI)principles of developing open-access databases and tools to reduce the cost and development time of materials discovery,optimization,and deployment.

关键词： automated JAR databases

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