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An optimization-Accelerated Electromagnetic Time Reversal-Based Fault Location Method for Power Lines With Branches

IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY 2023年第1期65卷 206-215页

作者： Wang, Guanbo Zhuang, Chijie Zeng, Rong Tsinghua Univ Dept Elect Engn Beijing 100084 Peoples R China Tsinghua Univ State Key Lab Power Syst Beijing 100084 Peoples R China Tsinghua Univ Int Joint Lab Low Carbon Clean Energy Innovat Beijing 100084 Peoples R China

It is very important to locate the short-circuit fault in a power system quickly and accurately. Electromagnetic time reversal (EMTR) has drawn increasing attention because of its clear physical background and excellent performance. This article studies the EMTR method for locating the short-circuit fault of transmission and distribution lines with or without branches, and introduces a simulated annealing algorithm to accelerate the calculation of an EMTR fault location. This algorithm is different from the traditional exhaustive method in that it solves the corresponding optimization problem, thus improving the location speed by up to an order of magnitude. With the help of graph theory, a method is proposed that automatically splits a complex line topology with branches into several one-dimensional (1-D) lines. The problem of short-circuit fault location in the branching lines is then transformed into several 1-D optimization problems, which are then solved by the optimization algorithm. This solves the problem of realizing rapid location in a power network with branches. Numerical experiments are carried out in a distribution network model to demonstrate the effectiveness of the method. Results under different conditions show the method works reliably and efficiently.

关键词： optimization Fault location Linear programming Circuit faults Propagation losses Power systems Electromagnetics Branched transmission line electromagnetic time reversal (EMTR) fault location graph theory optimization algorithm

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Research Progress of Aerodynamic Multi-Objective optimization on High-Speed Train Nose Shape

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Computer Modeling in Engineering & Sciences 2023年第11期137卷 1461-1489页

作者： Zhiyuan Dai Tian Li Weihua Zhang Jiye Zhang State Key Laboratory of Traction Power Southwest Jiaotong UniversityChengdu610031China

The aerodynamic optimization design of high-speed trains(HSTs)is crucial for energy conservation,environmental preservation,operational safety,and speeding *** study aims to review the current state and progress of the aerodynamic multi-objective optimization of ***,the study explores the impact of train nose shape parameters on aerodynamic *** parameterization methods involved in the aerodynamic multiobjective optimization ofHSTs are summarized and classified as shape-based and disturbance-based ***,the advantages and limitations of each parameterizationmethod,aswell as the applicable scope,are briefly *** addition,the NSGA-II algorithm,particle swarm optimization algorithm,standard genetic algorithm,and other commonly used multi-objective optimization algorithms and the improvements in the field of aerodynamic optimization for HSTs are ***,this study investigates the aerodynamic multi-objective optimization technology for HSTs using the surrogate model,focusing on the Kriging surrogate models,neural network,and support vector ***,the construction methods of surrogate models are summarized,and the influence of different sample infill criteria on the efficiency ofmulti-objective optimization is ***,advanced aerodynamic optimization methods in the field of aircraft have been briefly introduced to guide research on the aerodynamic optimization of ***,based on the summary of the research progress of the aerodynamicmulti-objective optimization ofHSTs,future research directions are proposed,such as intelligent recognition technology of characteristic parameters,collaborative optimization of multiple operating environments,and sample infill criterion of the surrogate model.

关键词： High-speed train multi-objective optimization parameterization optimization algorithm surrogate model sample infill criterion

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Contrast Enhancement in Images by Homomorphic Filtering and Cluster-Chaotic optimization

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IEEE ACCESS 2023年 11卷 73803-73822页

作者： Chavarin, Angel Cuevas, Erik Avalos, Omar Galvez, Jorge Perez-Cisneros, Marco Univ Guadalajara Dept Elect CUCEI Guadalajara 44100 Jalisco Mexico

Homomorphic filtering (HF) is a methodology that separates an image into two components: illumination and reflectance. Through the processing of these components, it is possible to significantly improve the contrast of the low-frequency components while preserving the edges and sharp features of the image. The parameter values of the filter that produces the best possible contrast enhancement depends on the image conditions for each image. However, finding the optimal parameters for the filter can be challenging, often involves a trial-and-error process, and can be prone to errors due to human factors. In this paper, we consider the problem of identifying the filter parameters as an optimization problem. Under such conditions, the cluster chaotic optimization (CCO) method is used to efficiently explore the parameter space by evaluating an objective function that assesses the contrast quality of an enhanced image. The experimental results show that the proposed method produces competitive results in terms of quality, stability, and accuracy compared with other methods on various datasets. Different metrics were evaluated to demonstrate the quality of the results of our method compared with the other algorithms.

关键词： Homomorphic filtering metaheuristic algorithms contrast enhancement optimization algorithm infrared images color images

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A novel variational optimization model for medical CT and MR image fusion

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SIGNAL IMAGE AND VIDEO PROCESSING 2023年第1期17卷 183-190页

作者： Wang, Qinxia Zuo, Mingcheng China Univ Min & Technol Artificial Intelligence Res Inst Xuzhou 221116 Jiangsu Peoples R China Nanjing Univ Sci & Technol Sch Sci Nanjing 210094 Peoples R China

In medical imaging processing, image fusion is the process of combining complementary information from different or multimodality images to obtain a high-quality and informative fused image in order to improve clinical diagnostic accuracy. In this paper, we propose a novel variational fusion model based on contrast and gradient features, the weight images and the fused images are constrained by the total variation regularization. The salient contrast features and clear soft tissue structure information of source CT and MR images can be preserved in the fused images. The variational problem is solved by a fast split optimization algorithm. In the numerical experiments, the proposed method is compared with seven state-of-the-art methods, and the comparison metrics MI, Q(W) and Q(G) are calculated for assessment. The proposed method shows a comprehensive advantage in preserving the contrast features as well as texture structure information, not only in visual effects but also in objective assessments.

关键词： Image fusion Variational model optimization algorithm Contrast Feature preservation

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A New optimization Control Policy for Fuzzy Vehicle Suspension Systems Under Membership Functions Online Learning

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IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS 2023年第5期53卷 3255-3266页

作者： Zhang, Zhenxing Dong, Jiuxiang Northeastern Univ Coll Informat Sci & Engn State Key Lab Synthet Automation Proc Ind Shenyang 110819 Peoples R China

Active vehicle suspension systems play a crucial role in isolating vibration between the car body and pavement. In this article, based upon Takagi-Sugeno (T-S) fuzzy model, a novel optimization control algorithm is first proposed to furthest improve driving comfort level for fuzzy suspension systems compared with traditional existing approach. First, sufficient criteria for designing non parallel distribution compensation (non-PDC) fuzzy controller to improve driving comfort level and guarantee corresponding suspension constrained requirements are presented. Then, in the context of ensuring stability of studied systems, considering the feasible areas of member-ship functions (MFs) of non-PDC controller, a new MFs online optimization strategy is built for fuzzy suspension systems for the first time. By this proposed novel optimization algorithm, the values of controller MFs (CMFs) can be updated in real-time so as to obtain a better driving comfort level while improv-ing suspension-constrained requirements. Sufficient criteria is obtained to guarantee the convergence of the designed cost function with the help of the Lyapunov stability theory. In the end, the usefulness, as well as superiority of the proposed online optimization strategy, are illustrated by contrastive verification.

关键词： Fuzzy vehicle suspension systems membership functions (MFs) online learning optimization algorithm Takagi-Sugeno (T-S) fuzzy model

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Developing aquila optimization-based fuzzy system to predict the mechanical properties of the improved HPC

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JOURNAL OF INTELLIGENT & FUZZY SYSTEMS 2023年第5期45卷 7859-7873页

作者： Ji, YingZhou Niuo, Qiang Guizhou Univ Sch Civil Engn Guiyang Guizhou Peoples R China Zhengzhou Univ Sci & Technol Fac Civil & Architectural Engn Zhengzhou Peoples R China

High-performance concrete performs better than normal concrete because of using additional components than usual concrete components. Several artificially based analytics were used to evaluate the compressive strength (CS) of high-performance concrete (HPC) made with fly ash and blast furnace slag. In the present research, the Aquila optimizer (AO) was used to find the best values for the determinants of the adaptive neuro-fuzzy inference system (ANFIS), and radial basis function neural network (RBFNN) that may be changed to enhance performance. The suggested approaches were established using 1030 tests, eight inputs (a primary component of mix designs, admixtures, aggregates, and curing age), and the CS as the forecasting objective. The results of the outperformed model were then contrasted with those found in the existing scientific literature. Calculation results point to the potential benefit of combining AO-RBFNN and AO-ANFIS study. The AO-ANFIS demonstrated significantly higher R-2 (Train: 0.9862, Test: 0.9922) and lower error metrics (such as: RMSE at 2.1434 (train) and 1.2763 (Test)) when compared to the AO-RBFNN and previously published articles. In summation, the proposed method for determining the CS of HPC supplemented with blast furnace slag and fly ash may be established using the suggested AO-ANFIS analysis.

关键词： High-performance concrete estimation artificial intelligence ANFIS optimization algorithm

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Real-Time Quadrotor Trajectory optimization with Time-Triggered Corridor Constraints

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2023年第6期46卷 1197-1205页

作者： Yu, Yue Nagpal, Kartik Mceowen, Skye Acikmese, Behcet Topcu, Ufuk Univ Texas Austin Oden Inst Computat Sci & Engn Austin TX 78712 USA Univ Washington Dept Aeronaut & Astronaut Seattle WA 98195 USA

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A new optimization method of energy consumption for dynamic boil-off gas

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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 2023年第83期48卷 32572-32587页

作者： Deng, Zhengrong An, Jinyu Xie, Chunxia Xu, Lisong Liu, Chenglong Mao, Ruiyong Guizhou Univ Collage Civil Engn Guiyang 550025 Peoples R China Guizhou Prov Key Lab Rock & Soil Mech & Engn Safe Guiyang 550025 Peoples R China

Related research on refrigerant optimization based on the dynamic BOG has yet to be proposed. This study offers a new dynamic optimization method for boil-off gas (BOG) reliquefaction system to improve the system's energy efficiency. The performance of C3MR (the propane precooling mixed refrigerant cycle) is analyzed based on the steady state model of leading liquefaction equipment in the process simulation in Aspen HYSYS software. And the principle of the energy consumption variation law of propane precooled compressor and mixed refrigerant compressor, based on the actual possible disturbance range obtained in the natural gas liquefaction process, is applied to construct the multiobjective optimization model with minimum energy consumption and maximum heat exchanger efficiency. Finally, the dynamic responses of disturbances were achieved and discussed with the aid of GA (Genetic algorithm) and PSO (particle swarm optimization). The optimized performance of the dynamic liquefaction cycle is 34.8% better than the steady condition system in terms of energy efficiency, and the maximum energy consumption can be reduced by 50.60%. The advantage of the proposed optimization frame-work is its adaptability to other dynamic liquefaction processes. It has practical reference significance for the cost control of the BOG re-liquefaction recovery project.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

关键词： Energy conservation C3MR process Exergy loss Dynamic BOG optimization algorithm

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Design of lossy three-element networks with optimization efficiency

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INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS 2023年第4期51卷 1596-1607页

作者： Wang, Bingting Cao, Ziping Yu, Wenjuan Li, Lingchun Zhou, Changhai Nanjing Univ Posts & Telecommun Coll Telecommun & Informat Engn Nanjing Peoples R China Chuzhou Univ Sch Mech & Elect Engn Chuzhou Peoples R China

Lumped passive elements are usually lossy because parasitic resistances dissipate the power transferred from the source to the load;thus, this loss influences the performance of the matching network. Furthermore, the impedances that need to be matched are usually complex-valued. In this paper, we described an optimization design method for lossy three-element network to achieve impedance matching between complex source and load impedances. We first determined the efficiency formulas for lossy pi$$ \Pi $$ and T networks via a generalized quality-based equation. Next, two methods were introduced to design the lossy pi$$ \Pi $$ and T networks with maximum efficiency. Finally, to validate the effectiveness of the designed lossy three-element networks, we conducted a series of numerical analysis and simulations, which indicates that the designed lossy pi$$ \Pi $$ and T networks exhibits excellent impedance matching performance at the desired frequency. For some instances, the lossy pi$$ \Pi $$ network with three elements exhibits a higher efficiency than a multistage matching network with more elements.

关键词： complex impedance lossy network maximum efficiency optimization algorithm

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Direct Simulation Monte Carlo Methods for Hypersonic Flows with Automatic Mesh optimization

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AIAA JOURNAL 2023年第1期61卷 5-22页

作者： Mallikarjun, Shrutakeerti Casseau, Vincent Habashi, Wagdi G. Gao, Song Karchani, Abolfazl McGill Univ Montreal PQ H3A 2M7 Canada Ansys Inc Montreal PQ H3A 3G4 Canada Ansys Inc Lebanon NH 03766 USA

High-Altitude Low-Orbit 3D (HALO3D) is a comprehensive multidisciplinary software system being developed by the current authors to simulate flowfields around hypersonic aircraft whose flightpath spans low (continuum) to high (rarefied) altitudes. This paper presents a methodology for coupling HALO3D's particle-based rarefied flow module, HALO3D-Direct Simulation Monte Carlo (HALO3D-DSMC), with a solution-driven edge-based automatic mesh optimization algorithm, OptiGrid. The paper studies the choice of optimization scalars and constraints for DSMC solvers, an aspect believed to be currently lacking in the literature. Three optimization constraints are used: minimum and maximum edge lengths and a target number of nodes/cells. Mesh optimization is conducted for Bird's leading-edge case and flows over two- and three-dimensional cylinder geometries for freestream Knudsen numbers ranging from 0.01 to 0.047. An adaptation scalar set combining flow variables such as density, velocity components, modal temperatures, pressure, and Mach number produces an unstructured collisional-sampling mesh that greatly improves the quality of the solution without necessarily increasing mesh size. The solutions represented by the optimal meshes are smooth and free of irregularities, with salient flow features being captured well. In addition, the coupled system can simulate complex geometries and multiscale flow features with arbitrarily generated initial grids.

关键词： Inviscid Hypersonic Flow Direct Simulation Monte Carlo Freestream Conditions Stagnation Region Leading Edges optimization algorithm Hypersonic Aircraft Flow Variables Shock Layers Boltzmann Transport Equation

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