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Stochastic dynamics and probability analysis for a generalized epidemic model with environmental noise

Chaos, Solitons & Fractals 2025年 199卷

作者： Brahim Boukanjime Mohamed Maama National School of Business and Management of Settat Hassan First University Morocco Applied Mathematics and Computational Science Program Computer Electrical and Mathematical Sciences and Engineering Division King Abdullah University of Science and Technology Kingdom of Saudi Arabia

In this paper we consider a stochastic SEIQR (Susceptible–Exposed–Infected–Quarantined–Recovered) epidemic model with a generalized incidence function. Using the Lyapunov method, we establish the existence and uniqueness of a global positive solution to the model, ensuring that it remains well-defined over time. We further establish V-geometric ergodicity, which guarantees the exponential convergence of the system’s probability distribution to its stationary measure, providing a quantitative measure of the system’s stability over time. By leveraging Young’s and Chebyshev’s inequalities, we demonstrate the concepts of stochastic ultimate boundedness and stochastic permanence, providing insights into the long-term behavior of the epidemic dynamics under random perturbations. Additionally, we derive conditions for stochastic extinction, which describes scenarios where the epidemic may eventually die out. Finally, we perform numerical simulations to verify our theoretical results and assess the model’s behavior under different parameters.

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Negative photo conductivity triggered with visible light in wide bandgap oxide-based optoelectronic crossbar memristive array for photograph sensing and neuromorphic computing applications

npj Unconventional Computing

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npj Unconventional Computing 2024年第1期1卷 1-9页

作者： Dayanand Kumar Hanrui Li Manoj Kumar Rajbhar Abdul Momin Syed Nazek El-Atab Amit Singh Hoonkyung Lee Smart Advanced Memory Devices and Applications (SAMA) Laboratory Electrical and Computer Engineering Program Computer Electrical Mathematical Science and Engineering Division King Abdullah University of Science and Technology (KAUST) Thuwal Saudi Arabia Department of Physics and Astronomy University of Manchester Manchester UK Department of Physics Konkuk University Seoul Republic of Korea

Photoresponsivity studies of wide-bandgap oxide-based devices have emerged as a vibrant and popular research area. Researchers have explored various material systems in their quest to develop devices capable of responding to illumination. In this study, we engineered a mature wide-bandgap oxide-based bilayer heterostructure synaptic memristor to emulate the human brain for applications in neuromorphic computing and photograph sensing. The device exhibits advanced electric and electrophotonic synaptic functions, such as long-term potentiation (LTP), long-term depression (LTD), and paired-pulse facilitation (PPF), by applying successive electric and photonic pulses. Moreover, the device exhibits exceptional electrical SET and photonic RESET endurance, maintaining its stability for a minimum of 1200 cycles without any degradation. Density functional theory calculations of the band structures provide insights into the conduction mechanism of the device. Based on this memristor array, we developed an autoencoder and convolutional neural network for noise reduction and image recognition tasks, which achieves a peak signal-to-noise ratio of 562 and high accuracy of 84.23%, while consuming lower energy by four orders of magnitude compared with the Tesla P40 GPU. This groundbreaking research not only opens doors for the integration of our device into image processing but also represents a significant advancement in the realm of in-memory computing and photograph-sensing features in a single cell.

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A Dual UPQC to Mitigate Sag/Swell, Interruption, and Harmonics on Three Phase Low Voltage Distribution System

A Dual UPQC to Mitigate Sag/Swell, Interruption, and Harmoni...

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Vocational Education and electrical engineering, International Conference on

作者： Amirullah Adiananda Ontoseno Penangsang Adi Soeprijanto Electrical Engineering Study Program Faculty of Engineering Universitas Bhayangkara Surabaya Surabaya Indonesia Faculty of Intelligent Electrical and Informatics Technology Institut Teknologi Sepuluh Nopember Surabaya Indonesia

ISBN: (数字)9781728174341

ISBN: (纸本)9781728174358

The Unified Power Quality Conditioner (UPQC) is a combination of a series active filter (SeAF) and a shunt active filter (ShAF) connected in parallel by a DC link capacitor. This device can mitigate power quality (PQ) problems i.e. sag/swell, harmonics, and unbalance on the source and load bus of threephase three-wire (3P3W) on low voltage distribution systems simultaneously. The disadvantage of UPQC is that it is unable to overcome the voltage interruption so that the source can not deliver power to the load. This paper proposes a dual UPQC model to overcome the voltage interruption on the source bus so that the load bus continues to get power supply. There are six disturbance cases i.e. sinusoidal supply-sag-non-linear load (SSag-NL-L), sinusoidal supply-swell-NL-L (S-Swell-NL-L), sinusoidal-interruption-NL-L (S-Inter-NL-L), distorted supplysag-NL-L load (D-Sag-NL-L), distorted supply-swell-NL-L (DSwell-NL-L), and distorted supply-interruption-NL-LL (DInter-NL-L). The proportional Integral (PI) method is used to control the SeAF and the ShAF in the dual UPQC circuit model. The simulation results show that in the D-Inter-NL-LL case, a Dual UPQC model can maintain a load voltage magnitude of 266.60 V (voltage drop only of 14%), higher compared to a Single UPQC model of 173.97 V (voltage drop of 43.88%). In the same case, a dual UPQC model is capable of resulting in an average total harmonics distortion (THD) of load voltage of 10.10%, lower compared to a single UPQC model of 26.70%.

关键词： Low voltage Simulation Power quality Harmonic analysis Integrated circuit modeling Power harmonic filters Load modeling

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Winter Cabin Water Tap Monitor and Release System to Reduce Risk of Freezing 10

Winter Cabin Water Tap Monitor and Release System to Reduce ...

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10th IEEE Annual Ubiquitous Computing, Electronics and Mobile Communication Conference, UEMCON 2019

作者： Kaprielian, Paul L. Pham, Thach Young, Alex Dow, Douglas E. Grenquist, Scott A. Decker, Bruce M. Program in Electronic Eng. Technology Wentworth Institute of Technology Dept. of Electrical and Computer Engineering BostonMA United States

ISBN: (纸本)9781728138855

Frozen water pipes lead to leaks that result in property damage and repair costs. Frozen water pipes not only occur in northern climates, but also in more moderate climates that have occasional periods of temperatures below the freezing point. Water pipes at high risk for ice formation include ones outside of buildings, in poorly insulated structures or in seasonal buildings that are not heated during the winter months. Methods of protection include heating the building, insulation and heat tape on exposed water pipes, turning off the water supply and draining all pipes of water, or turning on a water valve to allow a continual flow of water through the pipes during the entire period having risk of low temperatures. The flow would hinder ice formation in the pipes. These protective measures have associated costs for equipment, heating fuel, and water loss. If the low temperature drops further or is sustained for longer periods than expected, there would still be a risk of frozen pipes. The purpose of this project was to develop and test a prototype system to monitor temperature, and initiate intermittent bursts of water flow only when temperatures are low enough to have risk of ice formation in the water pipes. The prototype utilized a temperature sensor, Arduino microcontroller, power supply, relay switch, and solenoid valve. The solenoid valve was incorporated into the water facet of a sink. When the sensor detected temperatures below the threshold of 25°C, intermittent bursts of flow were initiated, with 20 seconds of water flow followed by 2 minutes of no flow. Each flow event was recorded in a web service. A HTTP Get request was transmitted to a Google App Script program that stored the date and time in a Google Sheet. The owner or manager could remotely monitor the intermittent flow events. © 2019 IEEE.

关键词： Temperature

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Dynamic State of BESS in Microgrids 19

Dynamic State of BESS in Microgrids

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19th IEEE International Conference on Environment and electrical engineering and 2019 IEEE Industrial and Commercial Power Systems Europe, EEEIC/I and CPS Europe 2019

作者： Pérez, G. Conde, A. Gutiérrez, G. Doctoral Program in Electrical Engineering Autonomous University of Nuevo Leon Nuevo Leon Mexico Department of Electrical Engineering Nacional Technology of Mexico/I.T.Morelia Mexico

ISBN: (纸本)9781728106526

This paper analyzes the impact of battery energy storage system (BESS) dynamics in micro grids subject to active power variations. The micro grid is connected to the utility through a high impedance feeder to consider poor contribution. Thus, the dynamic of the sources and loads connected will be greater to obtain a more complex operating scenario allowing the interaction between different types of non-regulated sources and energy storage systems. The microgrid can operate on island due to some contingency, by a normal operating condition or with a weak link;any of these conditions the energy required to supply the loads will depend meanly on the renewable and nonrenewable sources. The interconnection of the BESS in strategic points will allow to improve the regulation of energy. The latency times of battery charging and discharging and the limit of daily operations are shown as a real consideration in the control of the energy of the micro grid systems. The sizing and location of the batteries is made in the weakest nodes. The results show that the dynamic of BESS have an important impact in the energy availability for the microgrid operation. © 2019 IEEE.

关键词： Battery storage

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Power-and Current-Based Control of Distributed Inverters in Low-Voltage Microgrids: Considerations in Relation to Classic Droop Control 15

Power-and Current-Based Control of Distributed Inverters in ...

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15th International Conference on Ecological Vehicles and Renewable Energies, EVER 2020

作者： Marafao, Fernando P. Alonso, Augusto M. S. Gothner, Fredrik Tedeschi, Elisabetta Brandao, Danilo I. Sao Paulo State University Group of Automation and Int. Systems Sorocaba18087-180 Brazil Norwegian University of Science and Technology Department of Electric Power Engineering Trondheim7034 Norway Federal University of Minas Gerais Graduate Program in Electrical Engineering Belo Horizonte31270-901 Brazil

ISBN: (纸本)9781728156415

This paper addresses the matter of active and reactive power sharing among distributed inverters in low-voltage microgrids, particularly highlighting the peculiarities of two strategies of coordinated control based on a master/slave architecture, namely Power-and Current-Based Control, in comparison to the classic droop control approach. It is demonstrated that the Power-and Current-Based Control strategies present distinct operational features in relation to classic droop control, mostly concerning how active and reactive power are shared among inverters. Additionally, it is shown how the strategies differ in steady-state operation and response time while comparing to classic droop-based methods. Discussions are presented based on simulation results using Matlab/Simulink, comprising two distributed inverters in a low-voltage microgrid and considering different operational scenarios, such as load changes, existence of linear and nonlinear loads, as well as line impedance variations. Experimental results are presented to validate the expected behavior of one of the strategies. © 2020 IEEE.

关键词： Electric inverters

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Development of Low-Temperature Doping Process in Cdse-Nanocrystal Thin Films for Flexible Electronic and Optoelectronic Devices

SSRN

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SSRN 2022年

作者： Lee, Yong Min Jung, Byung Ku Ahn, Junhyuk Park, Taesung Shin, Chanho Ng, Tse Nga Kim, In Soo Choi, Ji-Hyuk Oh, Soong Ju Department of Semiconductor Systems Engineering Korea University Seoul02841 Korea Republic of Department of Materials Science and Engineering Korea University Seoul02841 Korea Republic of Materials Science Engineering Program Department of Electrical and Computer Engineering University of California San Diego La Jolla CA92093 United States Nanophotonics Research Center Korea Institute of Science and Technology Seoul02792 Korea Republic of Department of Converging Science and Technology KHU KIST Seoul02447 Korea Republic of Resources Utilization Research Center Korea Institute of Geoscience and Mineral Resources Daejeon34132 Korea Republic of

We introduce an effective surface-doping strategy for CdSe nanocrystals (NCs) by examining the size-dependency of the doping behavior. A CdSe NC thin-film transistor (TFT) is fabricated via a doping process with InCl3 treatment followed by an annealing process. Spectroscopic and electronic device characterization reveal that smaller NCs are more effectively doped than larger NCs at all annealing temperatures. This is attributed to the larger specific surface area, where the dopant can be more readily coordinated. The degenerate behavior of a 3.3-nm CdSe-NC TFT appears at a lower temperature than that of larger NC TFTs. We achieve a high electron mobility and on-to-off current ratio of 1.79 cm2/Vs and 5.2 × 105, respectively, in a low-temperature annealing process (150 °C) with 3.3-nm CdSe NCs. This facilitates the fabrication of a flexible CdSe-NC TFT, which is demonstrated on a polyethylene terephthalate substrate with an Al2O3 dielectric layer using atomic layer deposition. The flexible 3.3-nm CdSe-NC TFT is successfully fabricated even at 150 °C, with a high on-to-off current ratio and low hysteresis at a low operation voltage, which is impossible for larger CdSe-NC TFTs. © 2022, The Authors. All rights reserved.

关键词： Nanocrystals

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Skin effect in Non-Hermitian systems with spin

arXiv

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arXiv 2024年

作者： Zhang, Wenna Hu, Yutao Zhang, Hongyi Liu, Xiang Shen, Yuecheng Veronis, Georgios Alù, Andrea Huang, Yin Luo, Wenchen School of Physics Central South University Changsha410083 China Shenzhen Institute for Quantum Science and Engineering Southern university of science and technology Shenzhen518055 China State Key Laboratory of Precision Spectroscopy East China Normal University Shanghai200241 China School of Electrical Engineering and Computer Science Louisiana State University Baton RougeLA70803 United States Center for Computation and Technology Louisiana State University Baton RougeLA70803 United States Photonics Initiative Advanced Science Research Center City University of New York New YorkNY10031 United States Physics Program Graduate Center City University of New York New YorkNY10026 United States

The skin effect, where bulk modes collapse into boundary modes, is a key phenomenon in topological non-Hermitian systems, has been predominantly studied in spinless systems. Recent studies illustrate the magnetic suppression of the first-order skin effect while ignoring spin. However, the physical significance of a magnetic field in non-Hermitian skin effect with spin remains elusive. Here, we systematically explore non-Hermitian spinful systems based on generalized Hatano-Nelson models with SU(2) gauge potential fields. In an open one-dimensional lattice, the spin-up and spin-down states can be uniquely separated and localized at the two boundaries without magnetic field. When an external magnetic field is applied, the skin effect exhibits a smooth transition from bidirectional to unidirectional. Remarkably, we demonstrate that the first-order skin effect can be anomalously induced by a magnetic field in a topologically trivial non-Hermitian spinful system without any skin effect at zero field. The direction of such magnetically induced skin modes can be controlled by simply changing the amplitude and polarity of the magnetic field. In addition, we demonstrate a transition between non-Bloch PT and anti-PT symmetries in the system, and uncover the spin-dependent mechanism of non-Bloch PT symmetry. Our results pave the way for the investigation of non-Hermitian skin effect with spin degrees of freedom. © 2024, CC BY.

关键词： Magnetic field effects

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StyleKQC: A Style-Variant Paraphrase Corpus for Korean Questions and Commands

arXiv

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arXiv 2021年

作者： Cho, Won Ik Moon, Sangwhan Kim, Jong In Kim, Seok Min Kim, Nam Soo Department of Electrical and Computer Engineering INMC Seoul National University Korea Republic of Department of Computer Science Tokyo Institute of Technology Japan Google LLC Interdisciplinary Program in Cognitive Science Seoul National University Korea Republic of

Paraphrasing is often performed with less concern for controlled style conversion. Especially for questions and commands, style-variant paraphrasing can be crucial in tone and manner, which also matters with industrial applications such as dialog systems. In this paper, we attack this issue with a corpus construction scheme that simultaneously considers the core content and style of directives, namely intent and formality, for the Korean language. Utilizing manually generated natural language queries on six daily topics, we expand the corpus to formal and informal sentences by human rewriting and transferring. We verify the validity and industrial applicability of our approach by checking the adequate classification and inference performance that fit with conventional fine-tuning approaches, at the same time proposing a supervised formality transfer task. © 2021, CC BY-SA.

关键词： Natural language processing systems

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Sampled-Data Observer Design With Exponential Time-Varying Gains for Semilinear Parabolic PDE Systems

Sampled-Data Observer Design With Exponential Time-Varying G...

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Chinese Automation Congress (CAC)

作者： Zi-Peng Wang Huai-Ning Wu Han-Xiong Li Tingwen Huang Tao Shen School of Electrical Engineering University of Jinan Jinan China Science and Technology on Aircraft Control Laboratory School of Automation Science and Electrical Engineering Beihang University Beijing China City University of Hong Kong Hong Kong Science Program Texas A&M University at Qatar Doha Qatar HIT Robot Group Co. Ltd China

ISBN: (纸本)9781665426480

For semilinear parabolic PDE systems, the sampled-data observer (SDO) design under spatially point measurements (SPMs) with exponential time-varying gains is concerned. On basis of a Lyapunov functional, a SDO with exponential time-varying gains under SPMs via linear matrix inequalities is presented to guarantee the exponential stability of estimation error PDE system. Lastly, two numerical examples are provided to support the proposed SDO design approach.

关键词： Estimation error Automation Stability Observers Gain measurement Linear matrix inequalities Control theory

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