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Model for the structure function constant for index of refraction fluctuations in Rayleigh-Bénard turbulence

Physical Review Fluids 2024年第5期9卷 054605-054605页

作者： Robert A. Handler Richard J. Watkins Silvia Matt K. P. Judd Department of Mechanical Engineering George Mason University Fairfax Virginia 22030 USA Center for Simulation and Modeling George Mason University Fairfax Virginia 22030 USA Micro-Photonics Laboratory the Holcombe Department of Electrical and Computer Engineering Center for Optical Materials Science and Engineering Technologies (COMSET) Clemson University Clemson South Carolina 29634 USA Naval Research Laboratory Stennis Space Center Mississippi 39529 USA Naval Research Laboratory Washington DC 20375 USA

A model for the structure function constant associated with the index of refraction fluctuations in Rayleigh-Bénard turbulence is developed. The model is based upon the following assumptions: (1) the turbulence is homogeneous and isotropic at or near the midplane, (2) the rate of production is in balance with the rate of dissipation, (3) an inertial region exists, and (4) estimates for the rate of dissipation of temperature fluctuations and of turbulent kinetic energy can be made by assuming that the large-scale turbulence is dissipated in one eddy turnover time. From these assumptions, the dependence of the structure function on the geometry, heat flux, and the properties of the fluid is obtained. The model predicts that the normalized structure function constant is independent of the Rayleigh number. To verify the model, numerical simulations of Rayleigh-Bénard turbulence were performed using two different approaches: an in-house code based on a pseudospectral method, and a finite volume code which employs a model for the smallest scales of the turbulence. The model was found to agree with the results of the simulations, thereby lending support for the assumptions underlying the theory.

关键词： Rayleigh-Bénard convection Turbulence Direct numerical simulations

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A Smart Microgrid Approach for Distributed Network Combined with Power Line Fault Location Detection

A Smart Microgrid Approach for Distributed Network Combined ...

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2021 IEEE International Conference on Automatic Control and Intelligent Systems, I2CACIS 2021

作者： Khushi, Farha Motakabber, S.M.A. Bhattacharjee, Amit Zahirul Alam, A.H.A. Wong Azman, Amelia Hussain, Fayaz Kulliyyah of Engineering IIUM Dept. of Electronic and Computer Engineering Gombak Malaysia The City University Of New York Department Of Electrical And Computer Engineering New YorkNY United States Ton Duc Thang University Modeling Evolutionary Algorithms Simulation and Artificial Intelligence Faculty of Electrical Electronics Engineering Ho Chi Minh City Viet Nam

ISBN: (纸本)9781665403436

For every researcher, uncertainties connected to the Smart Grid and Distribution Network are a common element. Thousands of sources are part of the renewable energy system and they are situated at varying distances. In due course, certain sources may be inefficient, or a natural disaster can destroy the source causing power supply failures or require routine maintenance to improve service. Some of these defects grow slowly and some have a strong impact. The systems, however, contain safety components to remove the problem, but impact the generation of electricity and conduct intelligent grid errors. An intelligent microgrid should feature an intelligent fault location detection and fault removal device to avoid unwanted loads and insecurities. This research shaped a smart grid system, together with a defective technique to identify uncertainty efficiently. The originality of this research is to model an SMG based on an isolated small area's SGC mechanism in conjunction with a defective detecting system to manage uncertainties in an efficient way. The FLD technique is focused upon wavelet trigger signal and mathematical morphology method. In this approach, the wavelet activator signal created by the equivalent current or voltage for a short period of time is simulated to go to both terminals to determine that the fault takes place in the short branch using the mathematical morphological technique. The SMG modeled system is separated into a few branches for the FLD system. A smart technique is presented via mixed human machine interface (HMI) for SMG performance and FLD monitoring. The integrated process of the SMG system modeling in the MATLAB performance validation simulation platform. © 2021 IEEE.

关键词： Mathematical morphology

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Securing the light escaping in a Li-Fi network environment

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Procedia computer Science 2022年 201卷 684-689页

作者： D.D. Diambeki R.E. Mandiya K. Kyamakya S.K. Kasereka University of Kinshasa Mathematics and Computer Science Department Kinshasa DR Congo Artificial intelligence Big data and modeLing simulation research center (ABIL) Kinshasa Democratic Republic of the Congo Alpen-Adria-Universitaet Klagenfurt Institute of Smart Systems Technologies Department of Mathematical Sciences Klagenfurt Austria

Nowadays, everyone knows Wi-Fi. The technology that ensures connection of computer equipment. It is now positioned as the easiest way to interconnect multiple end users because It allows user mobility in workspaces, avoids cable clutter within the network coverage, such as offices, homes and so on. Despite these advantages, several scientific studies have shown that this technology can raise security and safety issues and is dangerous to human health, and therefore not suitable for hospital networks. In an attempt to overcome these difficulties, Li-Fi technology based on visible light is beginning to interest researchers. This technology is considered more secure than Wi-Fi because the light can be contained in a physical space and waves can’t pass through walls and other objects. Unfortunately, when the physical environment contains spaces that can escape light to the outdoors, this can be a security risk for Li-Fi because it uses light sources to transmit data. That why, in this paper, the main differences between Wi-Fi and Li-Fi technologies are explained, and a Li-Fi architecture provided with an authentification captive portal and a data transfer security mechanism between end users based on the AES algorithm is proposed. The developed prototype and the architecture proposed guarantee the security of the Li-Fi network even if the physical environment is provided with multiple light escape spaces.

关键词： Li-Fi (Light-Fidelity) VLC (Visible Light Communication) LED (Light Emitting Diode) Photodetector LDR (Light Dependent Resistor) Arduino AES algorithm Captive portal

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modeling and simulation to Improve Real Electric Vehicles Charging Processes by Integration of Renewable Energies and Buffer Storage

Modeling and Simulation to Improve Real Electric Vehicles Ch...

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simulation Winter Conference

作者： Konstantin Sing Pierre Mertiny Marco Pruckner Department of Mechanical Engineering University of Erlangen-Nürnberg Erlangen GERMANY Department of Mechanical Engineering University of Alberta Edmonton Alberta CANADA Modeling and Simulation Institute of Computer Science University of Würzburg Würzburg GERMANY

ISBN: (纸本)9781665476621

The present study explores a simulation model combining system dynamics and discrete-event simulation for an electric vehicle charging system. For the representation of the charging demand the model employs data from an actual facility for vehicle charging. While being connected to the electrical grid, the system is augmented by a solar photovoltaic installation and stationary battery energy storage. Multiple simulation runs were performed to analyze the considered energy system over a 1-year period and compare relevant output parameters for different system configurations and system locations. Results show that a solar photovoltaic installation can be effectively integrated. For the degree of self-sufficiency, high values of 87 % can be achieved with combined solar photovoltaic and battery energy storage systems.

关键词： Photovoltaic systems Renewable energy sources System dynamics Buffer storage Carbon dioxide Electric vehicle charging Data models

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Privacy sensitive large-margin model for face de-identification 1st

Privacy sensitive large-margin model for face de-identifica...

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1st International Conference on Neural Computing for Advanced Applications, NCAA 2020

作者： Guo, Zhiqiang Liu, Huigui Kuang, Zhenzhong Nakashima, Yuta Babaguchi, Noboru Key Laboratory of Complex Systems Modeling and Simulation School of Computer Science and Technology Hangzhou Dianzi University Hangzhou310018 China Osaka University Osaka Japan

ISBN: (纸本)9789811576690

There is an increasing concern of face privacy protection along with the wide application of big media data and social networks due to free online data release. Although some pioneering works obtained some achievements, they are not sufficient enough for sanitizing the sensitive identity information. In this paper, we propose a generative approach to de-identify face images yet preserving the non-sensitive information for data reusability. To ensure a high privacy level, we introduce a large-margin model for the synthesized new identities by keeping a safe distance with both the input identity and existing identities. Besides, we show that our face de-identification operation follows the (Formula Presented)-differential privacy rule which can provide a rigorous privacy notion in theory. We evaluate the proposed approach using the vggface dataset and compare with several state-of-the-art methods. The results show that our approach outperforms previous solutions for effective face privacy protection while preserving the major utilities. © Springer Nature Singapore Pte Ltd. 2020.

关键词： Privacy-preserving techniques

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Optimal vaccination and treatment policies with constrained inequalities to study limited vaccination resources for a multistrain reaction–diffusion SEIR model of COVID-19

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Partial Differential Equations in Applied Mathematics 2024年 10卷

作者： El Alami Laaroussi, Adil El Bhih, Amine Rachik, Mostafa Applied Mathematics and Computer Science Team Higher Normal School Tetuan Abdelmalek Essaadi University Tétouan Morocco Laboratory of Analysis Modeling and Simulation Department of Mathematics and Computer Science Faculty of Sciences Ben M'Sik Hassan II University Casablanca BP 7955 Morocco Multidisciplinary Research and Innovation Laboratory (LPRI) Moroccan School of Engineering Sciences (EMSI) Casablanca Morocco

The availability of an effective vaccine is a major challenge in COVID-19 vaccination campaigns. In this article, we propose a comprehensive strategy incorporating distributed controls via vaccination and treatment while considering the limitations of available resources expressed as inequalities constrained. Our approach utilizes a spatiotemporal model that includes multiple strains of the virus and considers spatial heterogeneity, providing a more accurate representation of disease transmission. By using a generalized two-strain ODE model, we effectively capture the evolution of COVID-19, including various strains and variants. To validate our model, we establish the positivity and boundedness of the system's solution. Through the exploration of vaccination and treatment controls. Our study aims to reduce the spread of the disease between strains and identify optimal values that minimize the number of infected individuals and associated costs. This work provides useful insights into effective strategies for controlling the COVID-19 epidemic, even with limited vaccination resources. Furthermore, we demonstrate the existence of controls and describe their characterizations in terms of state and adjoint functions. The penalty method is used to treat the inequalities constrained. More importantly, our numerical simulation shows that adequate vaccination resources and simultaneous treatment can effectively reduce and even eliminate the spread of COVID-19. © 2024 The Author(s)

关键词： Forward-Backward Sweep numerical method Limited vaccine supply Optimal control with inequalities constraints SEIR spatiotemporal and multi-strain model

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A Novel Smartphone-Based Human Activity Recognition Approach using Convolutional Autoencoder Long Short-Term Memory Network

A Novel Smartphone-Based Human Activity Recognition Approach...

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IEEE International Conference on Information Reuse and Integration (IRI)

作者： Dipanwita Thakur Sandip Roy Suparna Biswas Edmond S. L. Ho Samiran Chattopadhyay Sachin Shetty Department of Computer Science Banasthali Vidyapith Jaipur Rajasthan India Virginia Modeling Analysis and Simulation Center Old Dominion University Suffolk VA USA Department of Computer Science and Engineering Maulana Abul Kalam Azad University of Technology Kolkata India School of Computing Science University of Glasgow Scotland United Kingdom Department of Information Technology Jadavpur University Kolkata India

In smart and intelligent health care, smartphone sensor-based automatic recognition of human activities has evolved as an emerging field of research. In many application domains, deep learning (DL) strategies are more effective than conventional machine learning (ML) models, and human activity recognition (HAR) is no exception. In this paper, we propose a novel framework (CAEL-HAR), that combines CNN, Autoencoder and LSTM architectures for efficient smartphone-based HAR operation. There is a natural synergy between the modeling abilities of LSTMs, autoencoders, and CNNs. While AEs are used for dimensionality reduction and CNNs are the best at automating feature extraction, LSTMs excel at modeling time series. Taking advantage of their complementarity, the proposed methodology combines CNNs, AEs, and LSTMs into a single architecture. We evaluated the proposed architecture using the UCI, WISDM public benchmark datasets. The simulation and experimental results certify the merits of the proposed method and indicate that it outperforms computing time, F1-score, precision, accuracy, and recall in comparison to the current state-of-the-art methods.

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A Biased-Randomized Simheuristic for a Hybrid Flow Shop with Stochastic Processing Times in the Semiconductor Industry 22

A Biased-Randomized Simheuristic for a Hybrid Flow Shop with...

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Proceedings of the Winter simulation Conference

作者： Majsa Ammouriova Javier Panadero Madlene Leißau Christoph Laroque Christin Schumacher Angel A. Juan Computer Science Department Universitat Oberta de Catalunya Euncet Business School Barcelona SPAIN Institute for Management and Information University of Applied Sciences Zwickau Zwickau GERMANY Informatik 4 - Modeling and Simulation Department of Computer Science TU Dortmund University Dortmund GERMANY Dept. of Applied Statistics and Operations Research Universitat Politècnica de València Alcoy SPAIN

Compared to other industries, production systems in semiconductor manufacturing have an above-average level of complexity. Developments in recent decades document increasing product diversity, smaller batch sizes, and a rapidly changing product range. At the same time, the interconnections between equipment groups increase due to rising automation, thus making production planning and control more difficult. This paper discusses a hybrid flow shop problem with realistic constraints, such as stochastic processing times and priority constraints. The primary goal of this paper is to find a solution set (permutation of jobs) that minimizes the production makespan. The proposed algorithm extends our previous work by combining biased-randomization techniques with a discrete-event simulation heuristic. This simulation-optimization approach allows us to efficiently model dependencies caused by batching and by the existence of different flow paths. As shown in a series of numerical experiments, our methodology can achieve promising results even when stochastic processing times are considered.

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Mathematical modeling, sensitivity analysis, and optimal control of students awareness in mathematics education

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Partial Differential Equations in Applied Mathematics 2024年 11卷

作者： El Bhih, Amine Benfatah, Youssef Hassouni, Habib Balatif, Omar Rachik, Mostafa Laboratory of Analysis Modeling and Simulation Department of Mathematics and Computer Science Faculty of Sciences Ben M'Sik Hassan II University Multidisciplinary Research and Innovation Laboratory (LPRI) Moroccan School of Engineering Sciences (EMSI) Laboratory of Fundamental Mathematics and their Applications Department of Mathematics Faculty of Sciences El Jadida Chouaib Doukkali University

This article presents a continuous-time mathematical model, EFSMK, integrating various educational categories, serving as a valuable tool for understanding students interactions with mathematics. The paper begins by exploring the necessary preliminaries to describe the model. Subsequently, we examine the model's well-posedness, focusing on the positivity and boundedness of solutions. The basic reproduction number is then derived using the next-generation matrix method. The model exhibits two stable states: the mathematics-free equilibrium point and the learning equilibrium point for students who struggle with mathematics. The study shows that when the basic reproduction number is less than one, the mathematics-free equilibrium point is globally asymptotically stable. Conversely, when the basic reproduction number exceeds one, the learning equilibrium point for students who struggle with mathematics is globally asymptotically stable. Numerical simulations validate the theoretical findings. In the last part of the paper, we present a structured model involving two distinct strategies aimed at improving the mathematical skills of students who encounter difficulties in this subject. The first strategy consists of offering individualized or small-group tutoring sessions, focusing on challenging topics and using alternative teaching methods. The second strategy entails adjusting the overall program and pedagogical approach to better respond to diverse learning needs. This approach uses Pontryagin's maximum principle and iterative analysis to determine optimal controls. The effectiveness of these strategies is evaluated using numerical simulations in various scenarios. © 2024 The Author(s)

关键词： Forward-backward sweep numerical method Global stability Lyapunov's function Optimal control Sensitive analysis

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Design of an Incremental Conductance Maximum power point tracking Controller based on Automation PLC for PV Applications 3

Design of an Incremental Conductance Maximum power point tra...

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3rd International Conference on Electrical, Communication and computer Engineering, ICECCE 2021

作者： Yatlml, Hanane Ouberri, Youness Marah, Rim Aroudam, Elhassan Chahid, Sara Essaadi University Modeling and Simulation of Mechanical Systems Team Faculty of Sciences Physics Department Tetouan Morocco Essaadi University Computer Science and Systems Engineering Laboratory Faculty of Sciences Abdelmalek Tetouan Morocco Chapman University Advanced Physics Laboratory Institute for Quantum Studies BurtonsvilleMD United States

ISBN: (纸本)9781665438971

One of the most important concerns about the control of the PV system is the maximum power point tracking algorithms, their implementation in various electronic devices for multiple technologies, and then the improvement of the quality and the accuracy of the outcomes using different techniques. This paper presents a programmable logic controller software design for a standalone photovoltaic system, and a comparison analysis between the incremental conductance and the perturb and observe MPPT algorithms based on an automation approach. The simulation using an automation software (Siemens TIA portal) and the experimental implementation using an automation PLC (S7-1200 PLC) reveals that the later presents a good MPP tracker for both algorithms;the only difference was that the IC algorithm shows better performance and lower oscillation around the maximum power point. The implementation of the incremental conductance on the PLC program has many advantages compared to the perturb and observe algorithm: mended tracking of the maximum power point despite the various and the fast-changing on weather conditions, fewer oscillations around the maximum power point, fast response to the change on temperature and irradiation levels, better stability for battery charging signals. The entire PV system is simulating in Siemens total integration automation interface (TIA portal) and the results are plotting using Siemens Human Machine Interface (WinCC). © 2021 IEEE.

关键词： Maximum power point trackers

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