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Catalog of 525 Sprites Observed Over Japan from September 2016 to March 2021

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SSRN

SSRN 2022年

作者： Maomao, Duan Sakamoto, Takanori Enoto, Teruaki Wada, Yuuki Kamogawa, Masashi Ito, Koji Miyoshi, Terunori Sekiguchi, Takashi Shimoda, Chikara Kawakami, Hiroshi Department of Physical science Aoyama Gakuin University Kanagawa Prefecture Sagamihara City Japan Extreme Natural Phenomena RIKEN Hakubi Research Team Cluster for Pioneering Research RIKEN Saitama Japan Division of Electrical Electronic and Infocommunications Engineering Graduate School of Engineering Osaka University Osaka Japan Division for Earthquake Prediction Research Global Center for Asian and Regional Research University of Shizuoka Shizuoka Japan SonotaCo Network Japan Sambommatsu High School Kagawa Prefecture Higashikagawa Japan The Nippon Meteor Society Japan Japan Fireball Network Japan

We present a catalog of 525 sprites detected over the Sea of Japan and a northeast part of the Pacific Ocean from Sagamihara between September 2016 and March 2021. We analyze the morphology of 525, estimate the location of 441, and calculate the accurate top height of 15 sprites. More than half of our samples occurred in winter, while only 11% were in summer. In terms of morphology, most column type sprites took place in spring, autumn, and winter, while only 15.5% in summer. Therefore, summer thunderstorms are more likely to produce sprites with complex structures. Furthermore, sprites in summer are almost all located on the main island of Japan, and their spatial distributions are significantly different from the other seasons. © 2022, The Authors. All rights reserved.

关键词： Morphology

Burst-Deletion-Correcting Codes for Permutations and Multipermutations

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Burst-Deletion-Correcting Codes for Permutations and Multipe...

作者： Chee, Yeow Meng Ling, San Nguyen, Tuan Thanh Vu, Van Khu Wei, Hengjia Zhang, Xiande Department of Industrial Systems Engineering and Management National University of Singapore Singapore119077 Singapore School of Physical and Mathematical Sciences Nanyang Technological University Singapore639798 Singapore Department of Electrical and Computer Engineering Ben Gurion University of the Negev Beersheba8410501 Israel Division of Mathematical Sciences University of Science and Technology of China Hefei230026 China

Permutation codes and multipermutation codes are widely studied due to various applications in information theory. Designing codes correcting deletion errors has been the main subject of works in the literature and to the best of our knowledge, there exist only optimal codes capable of correcting a single deletion in a permutation. In this paper, we construct several classes of permutation and multipermutation codes that are capable of correcting a burst deletion of length s2, for both stable and unstable models. Efficient error decoders are provided to show the correctness of our constructions. © 1963-2012 IEEE.

关键词： Flash memory

Emulation of synaptic plasticity on cobalt based synaptic transistor for neuromorphic computing

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arXiv 2021年

作者： Monalisha, P. Anil Kumar, P.S. Renshaw Wang, X. Piramanayagam, S.N. Department of Physics Indian Institute of Science Bangalore560012 India Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University 637371 Singapore School of Electrical and Electronic Engineering Nanyang Technological University 637371 Singapore

Neuromorphic Computing (NC), which emulates neural activities of the human brain, is considered for low-power implementation of artificial intelligence. Towards realizing NC, fabrication, and investigations of hardware elements such as synaptic devices and neurons are essential. Electrolyte gating has been widely used for conductance modulation by massive carrier injections and has proven to be an effective way of emulating biological synapses. Synaptic devices, in the form of synaptic transistors, have been studied using a wide variety of materials. However, studies on metallic channel based synaptic transistors remain vastly unexplored. Here, we have demonstrated a three-terminal cobalt-based synaptic transistor to emulate biological synapse. We realized gating controlled multilevel, nonvolatile conducting states in the proposed device. The device could successfully emulate essential synaptic functions demonstrating short-term and long-term plasticity. A transition from short-term memory to long-term memory has been realized by tuning gate pulse amplitude and duration. The crucial cognitive behavior viz., learning, forgetting, and relearning, has been emulated, showing resemblance to the human brain. Along with learning and memory, the device showed dynamic filtering behavior. These results provide an insight into the design of metallic channel based synaptic transistors for neuromorphic computing. Copyright © 2021, The Authors. All rights reserved.

关键词： Ionic liquids

Question-Answering System Extracts Information on Injection Drug Use from Clinical Notes

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arXiv 2023年

作者： Mahbub, Maria Goethert, Ian Danciu, Ioana Knight, Kathryn Srinivasan, Sudarshan Tamang, Suzanne Rozenberg-Ben-Dror, Karine Solares, Hugo Martins, Susana Trafton, Jodie Begoli, Edmon Peterson, Gregory D. Cyber Resilience and Intelligence Division Oak Ridge National Laboratory Oak RidgeTN United States Information Technology Services Division Oak Ridge National Laboratory Oak RidgeTN United States Computational Sciences and Engineering Division Oak Ridge National Laboratory Oak RidgeTN United States Department of Biomedical Informatics Vanderbilt University NashvilleTN United States Program Evaluation and Resource Center Office of Mental Health and Suicide Prevention Department of Veterans Affairs United States Department of Medicine Stanford University School of Medicine StanfordCA United States Veterans Affairs Great Lakes Health Care System WestchesterIL United States Department of Electrical Engineering and Computer Science University of Tennessee Knoxville KnoxvilleTN United States

Background: Injection drug use (IDU) is a dangerous health behavior that increases mortality and morbidity. Identifying IDU early and initiating harm reduction interventions can benefit individuals at risk. However, extracting IDU behaviors from patients’ electronic health records (EHR) is difficult because there is no International Classification of Disease (ICD) code and the only place IDU information can be indicated is unstructured free-text clinical notes. Although natural language processing can efficiently extract this information from unstructured data, there are no validated tools. Methods: To address this gap in clinical information, we design and demonstrate a question-answering (QA) framework to extract information on IDU from clinical notes. Our framework involves two main steps: (1) generating a gold-standard QA dataset and (2) developing and testing the QA model. We utilize 2323 clinical notes of 1145 patients sourced from the VA Corporate Data Warehouse to construct the gold-standard dataset for developing and evaluating the QA model. We also demonstrate the QA model’s ability to extract IDU-related information on temporally out-of-distribution data. Results: Here we show that for a strict match between gold-standard and predicted answers, the QA model achieves 51.65% F1 score. For a relaxed match between the gold-standard and predicted answers, the QA model obtains 78.03% F1 score, along with 85.38% Precision and 79.02% Recall scores. Moreover, the QA model demonstrates consistent performance when subjected to temporally out-of-distribution data. Conclusions: Our study introduces a QA framework designed to extract IDU information from clinical notes, aiming to enhance the accurate and efficient detection of people who inject drugs, extract relevant information, and ultimately facilitate informed patient care. © 2023, CC BY-NC-ND.

关键词： Data warehouses

Non-volatile spin transport in a single domain multiferroic

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arXiv 2024年

作者： Husain, Sajid Harris, Isaac Meisenheimer, Peter Mantri, Sukriti Li, Xinyan Ramesh, Maya Behera, Piush Taghinejad, Hossein Kim, Jaegyu Kavle, Pravin Zhou, Shiyu Kim, Tae Yeon Zhang, Hongrui Stephenson, Paul Analytis, James G. Schlom, Darrell Salahuddin, Sayeef Íñiguez-González, Jorge Xu, Bin Martin, Lane W. Caretta, Lucas Han, Yimo Bellaiche, Laurent Yao, Zhi Ramesh, Ramamoorthy Materials Science Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Department of Physics University of California BerkeleyCA94720 United States Department of Materials Science and Engineering University of California BerkeleyCA94720 United States Physics Department Institute for Nanoscience and Engineering University of Arkansas FayettevilleAR72701 United States Materials Science and NanoEngineering Rice University HoustonTX77005 United States Department of Materials Science and Engineering Cornell University IthacaNY14850 United States University of California BerkeleyCA94720 United States Department of Physics Brown University ProvidenceRI02906 United States Department of Physics Northeastern University BostonMA02115 United States Department of Electrical Engineering and Computer Sciences University of California BerkeleyCA94720 United States Department of Materials Research and Technology Luxembourg Institute of Science and Technology 5 Avenue des Hauts-Fourneaux Esch/AlzetteL-4362 Luxembourg Department of Physics and Materials Science University of Luxembourg 41 Rue du Brill BelvauxL-4422 Luxembourg Institute of Theoretical and Applied Physics Jiangsu Key Laboratory of Thin Films School of Physical Science and Technology Soochow University Suzhou215006 China Department of Materials Science and NanoEngineering Chemistry and Physics and Astronomy Rice University HoustonTX77005 United States Rice Advanced Materials Institute Rice University HoustonTX77005 United States School of Engineering Brown University ProvidenceRI77005 United States

Antiferromagnets have attracted significant attention in the field of magnonics, as promising candidates for ultralow-energy carriers for information transfer for future computing. The role of crystalline orientation distribution on magnon transport has received very little attention. In multiferroics such as BiFeO3 the coupling between antiferromagnetic and polar order imposes yet another boundary condition on spin transport. Thus, understanding the fundamentals of spin transport in such systems requires a single domain, a single crystal. We show that through Lanthanum(La) substitution, a single ferroelectric domain can be engineered with a stable, single-variant spin cycloid, controllable by an electric field. The spin transport in such a single domain displays a strong anisotropy, arising from the underlying spin cycloid lattice. Our work shows a pathway to understand the fundamental origins of spin transport in such a single domain multiferroic. © 2024, CC BY.

关键词： Bismuth compounds

Terahertz sensing of highly absorptive water-methanol mixtures with Fano resonances in metamaterials

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arXiv 2022年

作者： Chen, Min Singh, Leena Xu, Ningning Singh, Ranjan Xie, Lijuan Zhang, Weili College of Biosystems Engineering and Food Science Zhejiang University 866 Yuhangtang Road Hangzhou310058 China School of Electrical and Computer Engineering Oklahoma State University StillwaterOK74078 United States Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore637371 Singapore Center for Disruptive Photonic Technologies The Photonics Institute Nanyang Technological University 50 Nanyang Avenue Singapore639798 Singapore

Ultrasensitive terahertz sensing of highly absorptive aqueous solutions remains challenging due to strong absorption of water in the terahertz regime. Here, we experimentally demonstrate a cost-effective metamaterial based sensor integrated with terahertz time-domain spectroscopy (THz-TDS) for highly absorptive water-methanol mixture sensing. This metamaterial has simple asymmetric wire structures that supports a fundamental Fano resonance and higher order dipolar resonance in the terahertz regime. Both the resonance modes has strong intensity in the transmission spectra which we exploit for detection of highly absorptive water-methanol mixtures. The experimentally measured sensitivities of the Fano and the dipole resonances for water-methanol mixtures are found to be 169, and 308 GHz/RIU, respectively. Such an ultrasensitive sensing provides a route for readily available metamaterial-assisted terahertz spectroscopy for ultrasensitive sensing of highly absorptive chemical and biochemical materials. © 2022, CC BY-NC-SA.

关键词： Metamaterials

Unbiased Estimation using a Class of Diffusion Processes

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arXiv 2022年

作者： Ruzayqat, Hamza Beskos, Alexandros Crisan, Dan Jasra, Ajay Kantas, Nikolas Applied Mathematics and Computational Science Program Computer Electrical and Mathematical Sciences and Engineering Division King Abdullah University of Science and Technology Thuwal23955-6900 KSA Saudi Arabia Department of Statistical Science University College London LondonWC1E 6BT United Kingdom Department of Mathematics Imperial College London LondonSW7 2AZ United Kingdom

We study the problem of unbiased estimation of expectations with respect to (w.r.t.) π a given, general probability measure on (d, B(d)) that is absolutely continuous with respect to a standard Gaussian measure. We focus on simulation associated to a particular class of diffusion processes, sometimes termed the Schrödinger-Föllmer Sampler, which is a simulation technique that approximates the law of a particular diffusion bridge process {Xt}tϵ[0,1]on d, d ϵ 0. This latter process is constructed such that, starting at X0= 0, one has X1∼ π. Typically, the drift of the diffusion is intractable and, even if it were not, exact sampling of the associated diffusion is not possible. As a result, [10, 16] consider a stochastic Euler-Maruyama scheme that allows the development of biased estimators for expectations w.r.t. π. We show that for this methodology to achieve a mean square error of O(ϵ2), for arbitrary ϵ > 0, the associated cost is O(ϵ-5). We then introduce an alternative approach that provides unbiased estimates of expectations w.r.t. π, that is, it does not suffer from the time discretization bias or the bias related with the approximation of the drift function. We prove that to achieve a mean square error of O(ϵ2), the associated cost (which is random) is, with high probability, O(ϵ-2| log(ϵ)|2+δ), for any δ > 0. We implement our method on several examples including Bayesian inverse *** Codes 60J60, 62D05, 65C40 © 2022, CC BY.

关键词： Diffusion

Tunable Localized Charge Transfer Excitons in a Mixed Dimensional van der Waals Heterostructure

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arXiv 2022年

作者： Rahaman, Mahfujur Marino, Emanuele Joly, Alan G. Song, Seunguk Jiang, Zhiqiao O’Callahan, Brian T. Rosen, Daniel J. Jo, Kiyoung Kim, Gwangwoo El-Khoury, Patrick Z. Murray, Christopher B. Jariwala, Deep Department of Electrical and Systems Engineering University of Pennsylvania PA19104 United States Department of Chemistry University of Pennsylvania PA19104 United States Dipartimento di Fisica e Chimica Università degli Studi di Palermo Via Archirafi 36 Palermo90123 Italy Physical and Chemical Sciences Division Pacific Northwest National Laboratory RichlandWA99352 United States Department of Materials Science and Engineering University of Pennsylvania PA19104 United States

Observation of interlayer, charge-transfer (CT) excitons in van der Waals heterostructures (vdWHs) based on 2D-2D systems has been well investigated. While conceptually interesting, these charge transfer excitons are highly delocalized and spatially localizing them requires twisting layers at very specific angles. This issue of localizing the CT excitons can be overcome via making mixed dimensional vdWHs (MDHs) where one of the components is a spatially quantum confined medium. Here, we demonstrate the formation of CT excitons in a 2D/quasi-2D system comprising MoSe2 and WSe2 monolayers and CdSe/CdS based core/shell nanoplates (NPLs). Spectral signatures of CT excitons in our MDHs were resolved locally at the 2D/single-NPL heterointerface using tip-enhanced photoluminescence (TEPL) at room temperature. By varying both the 2D material, the shell thickness of the NPLs, and applying out-of-plane electric field, the exciton resonance energy was tuned by up to 120 meV. Our finding is a significant step towards the realization of highly tunable MDH-based next generation photonic devices. © 2022, CC BY.

关键词： Selenium compounds

Applications of theoretical calculations in alkali metal-ion battery investigation

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Chinese Chemical Letters 2024年

作者： Hanmei Zhang Xiaoxu Liu Tianyi Ji Jianxin Ran Yang Li Zexiang Shen Xiaofeng Wang College of Mechanical & Electrical Engineering Shaanxi University of Science and Technology Xi'an 710021 China Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials School of Material Science and Engineering Shaanxi University of Science and Technology Xi'an 710021 China Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore

Alkali metal-ion batteries, such as lithium-ion and sodium-ion batteries, have been widely recognized by both academia and industry for their high energy density, long cycle life, low self-discharge rate, and environmental friendliness. Theoretical calculations are crucial in elucidating the energy storage mechanism of alkali metal-ion batteries and in designing the next generation of high-performance energy storage systems. This article reviews the application of theoretical calculations in alkali metal-ion batteries. These calculations are instrumental for experimental researchers in understanding the microscopic design of electrode materials, optimizing various interfaces and electrolyte structures, and clarifying ion and electron transport behaviors as well as electrochemical reaction mechanisms. Specifically, researchers typically calculate the reduction reactions, charge state changes, and structural changes of cathode materials to predict their electrochemical reactivity and optimize their performance and stability. Calculations and simulations of alkali metal batteries focus on ion transport dynamics within the electrolyte, including energy level distribution, solvation structure, and molecular dynamics simulations. Analyzing oxidation reactions, ion diffusion, and volume changes in various alkali metal-ion battery anode materials enables the screening and design of new anode materials with superior electrochemical properties. This review also discusses the challenges of applying theoretical calculations in alkali metal-ion batteries and provides an outlook for future research. Critical insights are offered for advancing research paradigms that integrate theoretical and experimental approaches in the development of energy storage electrode materials.

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