检索结果-内蒙古大学图书馆

Power engineering Conference (SAUPEC), Southern African Universities

作者： Nthabiseng Teffo Pitshou Bokoro Lutendo Muremi Thulane Paepae Department of Electrical and Electronic Engineering University of Johannesburg Johannesburg South Africa Department of Mathematics and Applied Mathematics University of Johannesburg Johannesburg South Africa

Electricity is an essential source in acquiring industrial and economic development in South Africa. Power distribution systems face daily challenges in tracing and estimating technical and non-technical losses. Non-technical losses (NTLs) like energy theft, poor meter readings and inadequate payments lead to anomalous spending and patterns. This work uses the buying data to assess the efficacy of Decision Trees (DT), Random Forest (RF), Extreme Gradient Boosting (XGBoost), Logistic Regression, Artificial Neural Networks, and K-Nearest Neighbors in predicting NTLs using a South African dataset. Comparatively, all the tree-based models (DT, RF, and XGBoost) achieved perfect scores across all evaluation metrics in classifying honest and dishonest customers.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Invertibility of Discrete-Time Linear Systems with Sparse Inputs 63

Invertibility of Discrete-Time Linear Systems with Sparse In...

引用

63rd IEEE Conference on Decision and Control, CDC 2024

作者： Poe, Kyle Mallada, Enrique Vidal, Rene University of Pennsylvania Applied Mathematics and Computational Science Group PA19104 United States Johns Hopkins University Mallada Is with the Department of Electrical and Computer Engineering MD21218 United States University of Pennsylvania Radiology Computer and Information Science Statistics and Data Science Departments of Electrical and Systems Engineering PA19104 United States

ISBN: (纸本)9798350316339

One of the fundamental problems of interest for discrete-time linear systems is whether its input sequence may be recovered given its output sequence, a.k.a. the left inversion problem. Many conditions on the state space geometry, dynamics, and spectral structure of a system have been used to characterize the well-posedness of this problem, without assumptions on the inputs. However, certain structural assumptions, such as input sparsity, have been shown to translate to practical gains in the performance of inversion algorithms, surpassing classical guarantees. Establishing necessary and sufficient conditions for left invertibility of systems with sparse inputs is therefore a crucial step toward understanding the performance limits of system inversion under structured input assumptions. In this work, we provide the first necessary and sufficient characterizations of left invertibility for linear systems with sparse inputs, echoing classic characterizations for standard linear systems. The key insight in deriving these results is in establishing the existence of two novel geometric invariants unique to the sparseinput setting, the weakly unobservable and strongly reachable subspace arrangements. By means of a concrete example, we demonstrate the utility of these characterizations. We conclude by discussing extensions and applications of this framework to several related problems in sparse control. © 2024 IEEE.

关键词： State space methods

来源：评论

学校读者我要写书评

暂无评论

Consensus-based Optimal Control Strategy for Multi-microgrid Systems with Battery Degradation Consideration

引用

CSEE Journal of Power and Energy Systems 2024年第5期10卷 1911-1924页

作者： Tonghe Wang Hong Liang Bo He Haochen Hua Yuchao Qin Junwei Cao Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640China Meihua Holdings Group Co. Ltd.Langfang 065001China. Department of Astronautical Science and Technology Space Engineering UniversityBeijing 101416China College of Energy and Electrical Engineering Hohai UniversityNanjing211100China Department of Applied Mathematics and Theoretical Physics University of CambridgeCambridgeCB30WAUK. Beijing National Research Center for Information Science and Technology Tsinghua UniversityBeijing 100084China

Consensus has been widely used in distributed control,where distributed individuals need to share their states with their neighbors through communication links to achieve a common ***,the objectives of existing consensus-based control strategies for energy systems seldom address battery degradation cost,which is an important performance indicator to assess the performance and sustainability of battery energy storage(BES)*** this paper,we propose a consensusbased optimal control strategy for multi-microgrid systems,aiming at multiple control objectives including minimizing battery degradation *** consensus is used to synchronize the ratio of BES output power to BES state-of-charge(SoC)among all microgrids while each microgrid is trying to reach its individual *** order to reduce the pressure of communication links and prevent excessive exposure of local information,this ratio is the only state variable shared between *** our complex nonlinear problem might be difficult to solve by traditional methods,we design a compressive sensing-based gradient descent(CSGD)method to solve the control *** simulation results show that our control strategy results in a 74.24%reduction in battery degradation cost on average compared to the control method without considering battery *** addition,the compressive sensing method causes an 89.12%reduction in computation time cost compared to the traditional Monte Carlo(MC)method in solving the control problem.

关键词： Battery degradation compressive sensing consensus distributed control multi-microgrid

来源：评论

学校读者我要写书评

暂无评论

The effect of underfloor heating on the amount of polluting matter in the air 23

The effect of underfloor heating on the amount of polluting ...

引用

23rd IEEE International Symposium on Computational Intelligence and Informatics, CINTI 2023

作者： Erchegyi, Attila Racz, Ervin Doctoral School of Applied Informatics and Applied Mathematics Óbuda University Budapest Hungary Evig Engineering Co. Ltd. Budapest Hungary Kandó Kálmán Faculty of Electrical Engineering Óbuda University Department of Natural Science Institute of Electrophysics Budapest Hungary

ISBN: (纸本)9798350342949

This article is about modelling of natural convection. It is discussed an everyday case of the physical operation of underfloor heating in a room, including the physical model, the software implementation, and the obtained results. Introduction is about its general description of the physical phenomena of underfloor heating, also the mathematical approximation of the heat transport processes. After that, paper talks about building the model, determine its input parameters, and specify the form of the expected output. The second chapter starts with a brief description of air pollution. The delivered equation is about to determine the local pollution value from the flow vectors which are obtained from the model. According to WHO's health limit values of polluting matters, a maximum and a volume-averaged level of pollution are determined based on the simulated data. Based on our research, the evaluated data shows that the underfloor heating is risk free in terms of long-term respiratory diseases for nontoxic solid pollutants. © 2023 IEEE.

关键词： Air quality

来源：评论

学校读者我要写书评

暂无评论

MINIMUM-RANK POSITIVE SEMIDEFINITE MATRIX COMPLETION WITH CHORDAL PATTERNS AND APPLICATIONS TO SEMIDEFINITE RELAXATIONS

Applied Set-Valued Analysis and Optimization

引用

applied Set-Valued Analysis and Optimization 2023年第2期5卷 265-283页

作者： Jiang, Xin Sun, Yifan Andersen, Martin S. Vandenberghe, Lieven Department of Industrial and Systems Engineering Lehigh University BethlehemPA18015-1582 United States Department of Computer Science Stony Brook University Stony BrookNY11794-2424 United States Department of Applied Mathematics and Computer Science Technical University of Denmark Kongens Lyngby Denmark Department of Electrical and Computer Engineering University of California Los Angeles Los AngelesCA90095 United States

We present an algorithm for computing the minimum-rank positive semidefinite completion of a sparse matrix with a chordal sparsity pattern. This problem is tractable, in contrast to the minimumrank positive semidefinite completion problem for general sparsity patterns. We also present a similar algorithm for the Euclidean distance matrix completion with minimum embedding dimension. The two algorithms use efficient recursions over a clique tree associated with the chordal sparsity pattern. As an application, we use the minimum-rank completion method as a rounding technique to convert the solution of a sparse semidefinite optimization problem with non-unique solutions to an optimal solution of lower rank. In experiments with semidefinite relaxations of optimal power flow problems, the minimum-rank completion often results in solutions of lower rank than the solutions computed by interior-point solvers. ©2023 applied Set-Valued Analysis and Optimization.

关键词： Electric load flow

来源：评论

学校读者我要写书评

暂无评论

Physical properties of relativistic electron beam during long-range propagation in space plasma environment

引用

Chinese Physics B 2021年第10期30卷 283-291页

作者： Bi-Xi Xue Jian-Hong Hao Qiang Zhao Fang Zhang Jie-Qing Fan Zhi-Wei Dong School of Electrical and Electronic Engineering Department North China Electric Power UniversityBeijing 102206China Institute of Applied Physics and Computational Mathematics Beijing 100094China

It is known that ion channel can effectively limit the radial expansion of an artificial electron beam during its longrange propagation in the space plasma *** prior studies discussed the focusing characteristics of the beam in the ion channel,but the establishment process and transient properties of the ion channel itself,which also plays a crucial role during the propagation of the relativistic electron beam in the plasma environment,were commonly *** this study,a series of two-dimensional(2D)particle-in-cell simulations is performed and an analytical model of ion channel oscillation is constructed according to the single-particle *** results showed that when the beam density is higher than the density of plasma environment,ion channel can be established and always continues to oscillate periodically over the entire *** factors,including the beam electron density,initial beam radius,and the plasma density can affect the oscillation properties of ion *** velocity of the beam oscillates synchronously with the ion channel and this phenomenon will finally develop into a two-stream instability which can seriously affect the effective transport for relativistic electron *** appropriate beam parameters based on various plasma environments may contribute to the improvement of the stability of ion ***,radial expansion of the beam can be limited by ion channel and a stable long-range propagation in terrestrial atmosphere may be achieved.

关键词： ion channel space plasma environment long-range propagation particle-in-cell(PIC)simulation

来源：评论

学校读者我要写书评

暂无评论

Performance Optimization of Series Resonant Converter by Combined Frequency and Duty Ratio Control

Performance Optimization of Series Resonant Converter by Com...

引用

On-Line Conference (ONCON), Industrial Electronics Society Annual

作者： Soham Chakraborty Supratik Bhowmick Suman Maiti Department of Applied Physics UG Program of Electrical Engineering Calcutta University Kolkata India Department of Electrical Engineering Indian Institute of Technology Kharagpur Kharagpur India

ISBN: (数字)9798331540319

ISBN: (纸本)9798331540326

Resonant converters are widely used for voltage regulator applications. The basic converters i.e., Series resonant Converter (SRC) and Parallel Resonant Converter (PRC) are having some merits and limitations. These are addressed in multi element topologies at the cost of adding extra elements. This work takes up the SRC and reports a combined frequency and duty ratio control for performance optimization of the SRC. The key issue of SRC is that the voltage cannot be controlled at a low Q (i.e. Quality factor) operation. For example, at no load Q becomes zero making the converter inert to frequency variation. This however can be eliminated by pulse width modulation technique. Duty ratio can be properly controlled to achieve the output voltage at an extended load range. The work further takes up challenge to make efficiency optimized. For this a combined control of duty ratio and frequency are proposed. Efficiency Optimization Control (EOC) requires two voltage sensors (one at the input side and another at the output) and a current sensor. Following this, a new minimum rms current algorithm is developed that only requires a current and a voltage sensor. All the proposed techniques are simulated and verified using MATLAB/Simulink.

关键词： Q-factor Frequency modulation Resonant frequency Resonant converters Frequency conversion Sensors Topology Voltage control Frequency control Optimization

来源：评论

学校读者我要写书评

暂无评论

A New Pulse Skipping Control for Series Resonant Converter

A New Pulse Skipping Control for Series Resonant Converter

引用

On-Line Conference (ONCON), Industrial Electronics Society Annual

作者： Supratik Bhowmick Soham Chakraborty Suman Maiti Department of Electrical Engineering Indian Institute of Technology Kharagpur Kharagpur India Department of Applied Physics UG Program of Electrical Engineering Calcutta University Kolkata India

ISBN: (数字)9798331540319

ISBN: (纸本)9798331540326

This paper proposes a pulse skipping based combined frequency and duty ratio control for a series resonant converter which is targeted for voltage regulator applications. The proposed pulse skipping control combines duty ratio based phase shifted control for maintaining output voltage at its reference value, along with frequency based control which assists in development of the pulse skipping algorithm. This algorithm is structured so that pulses are skipped in generated gate pulses for upper switching devices present in the converter whenever the output voltage tries to be higher than its specified maximum value or be lower than its specified minimum value. These maximum and minimum voltages are determined based on its reference voltage and allowable voltage ripple within which the oscillations in output voltage are desired to be in. The converter system with the proposed control method is simulated in MATLAB/Simulink environment to validate its performance under transient conditions e.g., variation in load resistance and output voltage reference. The system performance with proposed method is also compared with conventional method where the proposed control demonstrates its superiority by significantly minimizing the output voltage ripple.

关键词： Resistance Resonant frequency Resonant converters Logic gates Frequency conversion Voltage control Transient analysis MATLAB Frequency control Oscillators

来源：评论

学校读者我要写书评

暂无评论

Fuzzy Numbers and Analysis of Radiological Images

Fuzzy Numbers and Analysis of Radiological Images

引用

Intelligent and Fuzzy Systems - Intelligence and Sustainable Future Proceedings of the INFUS 2023 Conference

作者： Ibrišimović, Irma Iričanin, Bratislav Milosavljević, Nataša Nedović, Ljubo Ralević, Nebojša Faculty of Science Depertment of Mathematics University of Tuzla Tuzla Bosnia and Herzegovina Faculty of Technical Sciences Department of Fundamental Sciences University of Novi Sad Novi Sad Serbia Faculty of Electrical Engineering Department of Applied Mathematics University of Belgrade Belgrade Serbia Faculty of Agriculture Department of Mathematics and Physics University of Belgrade Belgrade Serbia

ISBN: (纸本)9783031397769

Fuzzy sets are a mathematical notion that allows us to represent uncertainty by assigning a degree of membership to a value in a range. This degree of membership represents the degree to which a particular value belongs to the fuzzy set. Fuzzy numbers are fuzzy sets that satisfy specific conditions, and can be applied in the interpretation of the behavior of neural networks. In many real-world problems, the output of a neural network may not be a precise numerical value, but rather a range of values that are subject to uncertainty. In the context of neural networks, fuzzy numbers can be used to represent uncertainty in the output of the network. Fuzzy numbers are used in applications where the representation of ambiguity and uncertainty in numerical data is explicitly desired. This paper will consider discretizations and defuzzifications triangular fuzzy numbers with the use of MATLAB® software. MATLAB® functions were applied to the analysis of kidney images, where the fuzzy numbers represent the tendency value of the degree of redness, which serves as an indicator for classifying the image as normal or abnormal based on different characteristics. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： MATLAB

来源：评论

学校读者我要写书评

暂无评论

Be Everywhere - Hear Everything (BEE): Audio Scene Reconstruction by Sparse Audio-Visual Samples

Be Everywhere - Hear Everything (BEE): Audio Scene Reconstru...

引用

International Conference on Computer Vision (ICCV)

作者： Mingfei Chen Kun Su Eli Shlizerman Department of Electrical & Computer Engineering University of Washington Department of Applied Mathematics University of Washington

Fully immersive and interactive audio-visual scenes are dynamic such that the listeners and the sound emitters move and interact with each other. Reconstruction of an immersive sound experience, as it happens in the scene, requires detailed reconstruction of the audio perceived by the listener at an arbitrary location. The audio at the listener location is a complex outcome of sound propagation through the scene geometry and interacting with surfaces and also the locations of the emitters and the sounds they emit. Due to these aspects, detailed audio reconstruction requires extensive sampling of audio at any potential listener location. This is usually difficult to implement in realistic real-time dynamic scenes. In this work, we propose to circumvent the need for extensive sensors by leveraging audio and visual samples from only a handful of A/V receivers placed in the scene. In particular, we introduce a novel method and end-to-end integrated rendering pipeline which allows the listener to be everywhere and hear everything (BEE) in a dynamic scene in real-time. BEE reconstructs the audio with two main modules, Joint Audio-Visual Representation, and Integrated Rendering Head. The first module extracts the informative audio-visual features of the scene from sparse A/V reference samples, while the second module integrates the audio samples with learned time-frequency transformations to obtain the target sound. Our experiments indicate that BEE outperforms existing methods by a large margin in terms of quality of sound reconstruction, can generalize to scenes not seen in training and runs in real-time speed.

关键词：

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：