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OPTIMALITY CONDITIONS AND DUALITY RESULTS FOR NONSMOOTH VECTOR OPTIMIZATION PROBLEMS WITH THE MULTIPLE INTERVAL-VALUED OBJECTIVE FUNCTION 被引量:5
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作者 Tadeusz ANTCZAK 《Acta Mathematica Scientia》 SCIE CSCD 2017年第4期1133-1150,共18页
In this paper, both Fritz John and Karush-Kuhn-Tucker necessary optimality conditions are established for a (weakly) LU-efficient solution in the considered nonsmooth multiobjective programming problem with the mult... In this paper, both Fritz John and Karush-Kuhn-Tucker necessary optimality conditions are established for a (weakly) LU-efficient solution in the considered nonsmooth multiobjective programming problem with the multiple interval-objective function. Further, the sufficient optimality conditions for a (weakly) LU-efficient solution and several duality results in Mond-Weir sense are proved under assumptions that the functions constituting the considered nondifferentiable multiobjective programming problem with the multiple interval- objective function are convex. 展开更多
关键词 nonsmooth multiobjective programming problem with the multiple interval- objective function Fritz John necessary optimality conditions Karush-Kuhn- Tucker necessary optimality conditions (weakly) LU-efficient solution Mond- Weir duality
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Modeling and multi-objective optimization of a gasoline engine using neural networks and evolutionary algorithms 被引量:7
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作者 JoséD. MARTíNEZ-MORALES Elvia R. PALACIOS-HERNáNDEZ Gerardo A. VELáZQUEZ-CARRILLO 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2013年第9期657-670,共14页
In this paper, a multi-objective particle swarm optimization (MOPSO) algorithm and a nondominated sorting genetic algorithm II (NSGA-II) are used to optimize the operating parameters of a 1.6 L, spark ignition (S... In this paper, a multi-objective particle swarm optimization (MOPSO) algorithm and a nondominated sorting genetic algorithm II (NSGA-II) are used to optimize the operating parameters of a 1.6 L, spark ignition (SI) gasoline engine. The aim of this optimization is to reduce engine emissions in terms of carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx), which are the causes of diverse environmental problems such as air pollution and global warming. Stationary engine tests were performed for data generation, covering 60 operating conditions. Artificial neural networks (ANNs) were used to predict exhaust emissions, whose inputs were from six engine operating parameters, and the outputs were three resulting exhaust emissions. The outputs of ANNs were used to evaluate objective functions within the optimization algorithms: NSGA-II and MOPSO. Then a decision-making process was conducted, using a fuzzy method to select a Pareto solution with which the best emission reductions can be achieved. The NSGA-II algorithm achieved reductions of at least 9.84%, 82.44%, and 13.78% for CO, HC, and NOx, respectively. With a MOPSO algorithm the reached reductions were at least 13.68%, 83.80%, and 7.67% for CO, HC, and NOx, respectively. 展开更多
关键词 Engine calibration Multi-objective optimization Neural networks multiple objective particle swarm optimization(MOPSO) Nondominated sorting genetic algorithm II (NSGA-II)
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MODS: A Novel Metaheuristic of Deterministic Swapping for the Multi-Objective Optimization of Combinatorials Problems
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作者 Elias David Nifio Ruiz Carlos Julio Ardila Hemandez +2 位作者 Daladier Jabba Molinares Agustin Barrios Sarmiento Yezid Donoso Meisel 《Computer Technology and Application》 2011年第4期280-292,共13页
This paper states a new metaheuristic based on Deterministic Finite Automata (DFA) for the multi - objective optimization of combinatorial problems. First, a new DFA named Multi - Objective Deterministic Finite Auto... This paper states a new metaheuristic based on Deterministic Finite Automata (DFA) for the multi - objective optimization of combinatorial problems. First, a new DFA named Multi - Objective Deterministic Finite Automata (MDFA) is defined. MDFA allows the representation of the feasible solutions space of combinatorial problems. Second, it is defined and implemented a metaheuritic based on MDFA theory. It is named Metaheuristic of Deterministic Swapping (MODS). MODS is a local search strategy that works using a MDFA. Due to this, MODS never take into account unfeasible solutions. Hence, it is not necessary to verify the problem constraints for a new solution found. Lastly, MODS is tested using well know instances of the Bi-Objective Traveling Salesman Problem (TSP) from TSPLIB. Its results were compared with eight Ant Colony inspired algorithms and two Genetic algorithms taken from the specialized literature. The comparison was made using metrics such as Spacing, Generational Distance, Inverse Generational Distance and No-Dominated Generation Vectors. In every case, the MODS results on the metrics were always better and in some of those cases, the superiority was 100%. 展开更多
关键词 METAHEURISTIC deterministic finite automata combinatorial problem multi - objective optimization metrics.
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Optimality and Duality on Fractional Multi-objective Programming Under Semilocal E-convexity 被引量:1
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作者 HU Qing-jie XIA O Yun-hai CHEN Nei-ping 《Chinese Quarterly Journal of Mathematics》 CSCD 2009年第2期200-210,共11页
In this paper, some necessary and sufficient optimality conditions are obtained for a fractional multiple objective programming involving semilocal E-convex and related functions. Also, some dual results are establish... In this paper, some necessary and sufficient optimality conditions are obtained for a fractional multiple objective programming involving semilocal E-convex and related functions. Also, some dual results are established under this kind of generalized convex functions. Our results generalize the ones obtained by Preda[J Math Anal Appl, 288(2003) 365-382]. 展开更多
关键词 semilocal E-convex functions fractional multiple objective programming optimality conditions DUALITY
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Multiple objectives application approach to waste minimization
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作者 张清宇 《Journal of Zhejiang University Science》 CSCD 2002年第4期405-411,共7页
Besides economics and controllability, waste minimization has now become an objective in designing chemical processes, and usually leads to high costs of investment and operation. An attempt was made to minimize waste... Besides economics and controllability, waste minimization has now become an objective in designing chemical processes, and usually leads to high costs of investment and operation. An attempt was made to minimize waste discharged from chemical reaction processes during the design and modification process while the operation conditions were also optimized to meet the requirements of technology and economics. Multiobjectives decision nonlinear programming (NLP) was employed to optimize the operation conditions of a chemical reaction process and reduce waste. A modeling language package-SPEEDUP was used to simulate the process. This paper presents a case study of the benzene production process. The flowsheet factors affecting the economics and waste generation were examined. Constraints were imposed to reduce the number of objectives and carry out optimal calculations easily. After comparisons of all possible solutions, best-compromise approach was applied to meet technological requirements and minimize waste. 展开更多
关键词 Waste minimization multiple objectives optimization Chemical reaction process.
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Solution and order number methods for multiple objective decision maki
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作者 蒋一初 《西南师范大学学报(自然科学版)》 CAS CSCD 1994年第4期346-349,共4页
Solutionandordernumbermethodsformultipleob-jectivedecisionmakingwithincompleteknowledgeJiangYichu(Department... Solutionandordernumbermethodsformultipleob-jectivedecisionmakingwithincompleteknowledgeJiangYichu(DepartmentofMathematics,Sou... 展开更多
关键词 多目标决策问题 优序法
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Multi-objective route planning approach for timely searching tasks of a supervised robot
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作者 刘鹏 熊光明 +2 位作者 李勇 姜岩 龚建伟 《Journal of Beijing Institute of Technology》 EI CAS 2014年第4期481-489,共9页
To performance efficient searching for an operator-supervised mobile robot, a multiple objectives route planning approach is proposed considering timeliness and path cost. An improved fitness function for route planni... To performance efficient searching for an operator-supervised mobile robot, a multiple objectives route planning approach is proposed considering timeliness and path cost. An improved fitness function for route planning is proposed based on the multi-objective genetic algorithm (MOGA) for multiple objectives traveling salesman problem (MOTSP). Then, the path between two route nodes is generated based on the heuristic path planning method A *. A simplified timeliness function for route nodes is proposed to represent the timeliness of each node. Based on the proposed timeliness function, experiments are conducted using the proposed two-stage planning method. The experimental results show that the proposed MOGA with improved fitness function can perform the searching function well when the timeliness of the searching task needs to be taken into consideration. 展开更多
关键词 multiple objective optimization multi-objective genetic algorithm supervised robots route planning TIMELINESS
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Optimization of CNC Turning Machining Parameters Based on Bp-DWMOPSO Algorithm
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作者 Jiang Li Jiutao Zhao +3 位作者 Qinhui Liu Laizheng Zhu Jinyi Guo Weijiu Zhang 《Computers, Materials & Continua》 SCIE EI 2023年第10期223-244,共22页
Cutting parameters have a significant impact on the machining effect.In order to reduce the machining time and improve the machining quality,this paper proposes an optimization algorithm based on Bp neural networkImpr... Cutting parameters have a significant impact on the machining effect.In order to reduce the machining time and improve the machining quality,this paper proposes an optimization algorithm based on Bp neural networkImproved Multi-Objective Particle Swarm(Bp-DWMOPSO).Firstly,this paper analyzes the existing problems in the traditional multi-objective particle swarm algorithm.Secondly,the Bp neural network model and the dynamic weight multi-objective particle swarm algorithm model are established.Finally,the Bp-DWMOPSO algorithm is designed based on the established models.In order to verify the effectiveness of the algorithm,this paper obtains the required data through equal probability orthogonal experiments on a typical Computer Numerical Control(CNC)turning machining case and uses the Bp-DWMOPSO algorithm for optimization.The experimental results show that the Cutting speed is 69.4 mm/min,the Feed speed is 0.05 mm/r,and the Depth of cut is 0.5 mm.The results show that the Bp-DWMOPSO algorithm can find the cutting parameters with a higher material removal rate and lower spindle load while ensuring the machining quality.This method provides a new idea for the optimization of turning machining parameters. 展开更多
关键词 Machining parameters Bp neural network multiple objective Particle Swarm optimization Bp-DWMOPSO algorithm
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Optimality and Duality for Nondifferentiable Multiple-Objective Optimization with Generalized Univexity
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作者 ZHOU Hou-chun 1, QIU Yong-ping 21.Department of Mathematics, Shandong Linyi Teacher′s College, Shandong 276005, China2.Department of Mathematics, Shandong Jinan Educational College, Jinan 250002, China 《Journal of Systems Science and Systems Engineering》 SCIE EI CSCD 2001年第2期162-172,共11页
Using generalized univex functions, a nondifferentiable multiple-objective optimization problem is considered.Kuhn-Tucker type sufficient optimality conditions are obtained for a feasible point to be an efficient or p... Using generalized univex functions, a nondifferentiable multiple-objective optimization problem is considered.Kuhn-Tucker type sufficient optimality conditions are obtained for a feasible point to be an efficient or properly efficient solution. Mond-Weir type duality programming is constructed,the weak and strong duality theorems are proved. 展开更多
关键词 multiple-objective optimization efficient solutions properly efficient solutions
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GPPre:A Python⁃Based Tool in Grasshopper for Office Building Performance Optimization
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作者 Hui Ren Shoulong Wang 《Journal of Harbin Institute of Technology(New Series)》 CAS 2021年第5期47-60,共14页
With the development of the economic and low⁃carbon society,high⁃performance building(HPB)design plays an increasingly important role in the architectural area.The performance of buildings usually includes the buildin... With the development of the economic and low⁃carbon society,high⁃performance building(HPB)design plays an increasingly important role in the architectural area.The performance of buildings usually includes the building energy consumption,building interior natural daylighting,building surface solar radiation,and so on.Building performance simulation(BPS)and multiple objective optimizations(MOO)are becoming the main methods for obtaining a high performance building in the design process.Correspondingly,the BPS and MOO are based on the parametric tools,like Grasshopper and Dynamo.However,these tools are lacking the data analysis module for designers to select the high⁃performance building more conveniently.This paper proposes a toolkit“GPPre”developed based on the Grasshopper platform and Python language.At the end of this paper,a case study was conducted to verify the function of GPPre,which shows that the combination of the sensitivity analysis(SA)and MOO module in the GPPre could aid architects to design the buildings with better performance. 展开更多
关键词 GPPre building performance simulation multiple objective optimizations high⁃performance building Python language
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Land use structural optimization of Lilin based on GMOP-ESV
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作者 ZHANG He-bing ZHANG Xiao-hu 《中国有色金属学会会刊:英文版》 CSCD 2011年第S3期738-742,共5页
Land use structural optimization is an effective approach to realize land sustainable utilization and allocate limited land resource rationally.Grey multiple objectives programming(GMOP)model based on China terrestria... Land use structural optimization is an effective approach to realize land sustainable utilization and allocate limited land resource rationally.Grey multiple objectives programming(GMOP)model based on China terrestrial ecosystem service value was constructed and applied to Lilin town.The result shows that GMOP model has more practical applicability and takes ecologic,social and comprehensive benefit into consideration.There are three programs after optimization.ProgramⅠis comprehensive improvement and constructing ecological economy type,programⅡis gross cultivated land dynamic balance type and programⅢis compromise type.There are still problems in programsⅡandⅢ,such as distribution in disorder,land left unused or abandoned.Based on the benefits above,ProgramⅠ>ProgramⅢ>ProgramⅡ.ProgramⅠis the optimal case.Its comprehensive benefit is 8.43208×107 RMB yuan/a. 展开更多
关键词 land use structure optimization grey multiple objective programming ecosystem service value Lilin town
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Optimal planning of energy storage system in active distribution system based on fuzzy multi-objective bi-level optimization 被引量:12
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作者 Rui LI Wei WANG +1 位作者 Zhe CHEN Xuezhi WU 《Journal of Modern Power Systems and Clean Energy》 SCIE EI 2018年第2期342-355,共14页
A fuzzy multi-objective bi-level optimization problem is proposed to model the planning of energy storage system(ESS) in active distribution systems(ADS). The proposed model enables us to take into account how optimal... A fuzzy multi-objective bi-level optimization problem is proposed to model the planning of energy storage system(ESS) in active distribution systems(ADS). The proposed model enables us to take into account how optimal operation strategy of ESS in the lower level can affect and be affected by the optimal allocation of ESS in the upper level. The power characteristic model of micro-grid(MG)and typical daily scenarios are established to take full consideration of time-variable nature of renewable energy generations(REGs) and load demand while easing the burden of computation. To solve the bi-level mixed integer problem, a multi-subgroup hierarchical chaos hybrid algorithm is introduced based on differential evolution(DE) and particle swarm optimization(PSO). The modified IEEE-33 bus benchmark distribution system is utilized to investigate the availability and effectiveness of the proposed model and the hybrid algorithm. Results indicate that the planningmodel gives an adequate consideration to the optimal operation and different roles of ESS, and has the advantages of objectiveness and reasonableness. 展开更多
关键词 ACTIVE distribution SYSTEM Energy STORAGE SYSTEM optimal PLANNING Bi-level PROGRAMMING FUZZY multiple objective
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Multi-objective interplanetary trajectory optimization combining low-thrust propulsion and gravity-assist maneuvers 被引量:8
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作者 SHEN HongXin ZHOU JianPing +2 位作者 PENG QiBo LI HaiYang LI JiuTian 《Science China(Technological Sciences)》 SCIE EI CAS 2012年第3期841-847,共7页
To expand mission capabilities needed without a proportional increase in cost or risk for exploration of the solar system,the multiple objective trajectory using low-thrust propulsion and gravity-assist technique is c... To expand mission capabilities needed without a proportional increase in cost or risk for exploration of the solar system,the multiple objective trajectory using low-thrust propulsion and gravity-assist technique is considered.However,low-thrust,gravity-assist trajectories pose significant optimization challenges because of their large design space.Here,the planets are selected as primal scientific mission goals,while the asteroids are selected as secondary scientific mission goals,and a global trajectory optimization problem is introduced and formulated.This multi-objective decision making process is transformed into a bi-level programming problem,where the targets like planets with small subsamples but high weight are optimized in up level,and targets like asteroids with large subsamples but low weight are optimized in down level.Then,the selected solutions for bi-level programming are optimized thanks to a cooperative Differential Evolution(DE) algorithm that is developed from the original DE algorithm;in addition,an sequential quadratic programming(SQP) method is used in low-thrust optimization.This solution approach is successfully applied to the simulation case of the multi-objective trajectory design problem.The results obtained are presented and discussed. 展开更多
关键词 trajectory optimization low thrust gravity assist multiple objective mission differential evolution
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A Compromise Approach to Lexicographic Optimal Solution in Multiple Objective Programming
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作者 XU Jiuping Department of Applied Mathematics, Chengdu University of Science and Technology, Chengdu, 610065 SHI Yong College of Business Administration, University of Nebraska at Omaha,Omaha, NE 68182, USA 《Systems Science and Systems Engineering》 CSCD 1997年第3期62-67,共6页
In this paper we use a compromise approach to identify a lexicographic optimal solution of a multiple objective programming (MOP) problem. With this solution concept, we first find the maximization of each objection f... In this paper we use a compromise approach to identify a lexicographic optimal solution of a multiple objective programming (MOP) problem. With this solution concept, we first find the maximization of each objection function as the ideal value. Then, we construct a lexicographic order for the compromise (differences) between the ideal values and objective functions. Based on the usually lexicographic optimality structure, we discuss some theoretical properties about our approach and derive a constructing algorithm to compute such a lexicographic optimal solution. 展开更多
关键词 multiple objective programming compromise approach lexicographic optimal solution algorithm
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基于多目标鱼群-蚁群算法的水资源优化配置 被引量:22
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作者 侯景伟 孔云峰 孙九林 《资源科学》 CSSCI CSCD 北大核心 2011年第12期2255-2261,共7页
为了解决复杂的水资源优化配置问题和丰富智能优化方法在水资源优化配置中的应用,建立了以经济、社会、环境综合效益最大为目标的水资源优化配置模型和多目标鱼群-蚁群算法。经济效益以区域供水带来的直接经济效益最大为目标;社会效益... 为了解决复杂的水资源优化配置问题和丰富智能优化方法在水资源优化配置中的应用,建立了以经济、社会、环境综合效益最大为目标的水资源优化配置模型和多目标鱼群-蚁群算法。经济效益以区域供水带来的直接经济效益最大为目标;社会效益以区域总缺水量最小为目标;生态环境效益以区域重要污染物排放量最小为目标;约束条件包括供水、需水、水环境和经济发展协调度等。多目标鱼群-蚁群算法融合了人工鱼群算法的快速跟踪变化和跳出局部极值优点以及蚁群算法的信息素正反馈优点,并将人工鱼群算法中的拥挤度概念引入到蚁群算法中,避免了蚁群算法初期可能早熟的问题。通过实验仿真,此算法具有较快的收敛速度和较高的寻优性能,能有效地找到优化解,从而为解决复杂的水资源优化配置问题提供了新的思路。 展开更多
关键词 水资源 优化配置 多目标 鱼群-蚁群算法 人工鱼群算法 蚁群算法
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基于P-AWPSO算法的全钒液流电池储能系统功率分配 被引量:9
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作者 邱亚 李鑫 +1 位作者 陈薇 段泽民 《高电压技术》 EI CAS CSCD 北大核心 2020年第2期500-510,共11页
为了提高全钒液流电池储能系统的效率,促进其高效利用,提出基于P-AWPSO(priority-adaptive weight particle swarm optimization)的功率分配策略。首先给出包含折损成本、损耗率及电池荷电状态(state of charge,SOC)一致性的多目标优化... 为了提高全钒液流电池储能系统的效率,促进其高效利用,提出基于P-AWPSO(priority-adaptive weight particle swarm optimization)的功率分配策略。首先给出包含折损成本、损耗率及电池荷电状态(state of charge,SOC)一致性的多目标优化模型以及4个评价全钒液流电池储能系统功率分配的指标;然后采用P-AWPSO算法进行求解,该算法采用"先选择单元后功率分配"的思路,即先根据优先级选择参与本次功率分配的储能单元,然后在选定的储能单元内进行功率分配;最后将算法用于两个算例的仿真中,并与传统功率分配算法进行了对比。通过仿真表明,该策略能够实现全钒液流电池储能系统的功率分配,减少电池充放电次数,降低电池运行成本,提高工作效率。 展开更多
关键词 全钒液流电池 电池储能系统 功率分配 P-AWPSO算法 多目标优化
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无线传感器网络TDMA调度的能量-时延Pareto优化 被引量:4
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作者 毛剑琳 吴智铭 《控制与决策》 EI CSCD 北大核心 2007年第9期967-971,共5页
针对多到一数据传输模式的无线传感器网络,提出了多目标TDMA(时分多址)调度优化模型,考虑了数据包的时延和节点状态切换导致的能量消耗,合理地建立了TDMA调度问题和进化搜索算法间的映射关系,并设计了基于微粒群的Pareto优化算法.仿真... 针对多到一数据传输模式的无线传感器网络,提出了多目标TDMA(时分多址)调度优化模型,考虑了数据包的时延和节点状态切换导致的能量消耗,合理地建立了TDMA调度问题和进化搜索算法间的映射关系,并设计了基于微粒群的Pareto优化算法.仿真实验表明,该算法可以有效地找到一组能量和时延目标的Pareto优化解,其结果优于图着色算法. 展开更多
关键词 无线传感器网络 时分多址 微粒群优化算法 多目标优化 PARETO优化
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采用动态多子群GSA-RBF神经网络的机车黏着优化控制 被引量:8
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作者 李宁洲 冯晓云 卫晓娟 《铁道学报》 EI CAS CSCD 北大核心 2014年第12期27-34,共8页
为解决机车牵引过程中轮轨间最优黏着利用能否获得的问题,提出一种基于高斯RBF神经网络的机车黏着智能优化控制方法。针对黏着极限态优化控制效果的定量评估,定义了同时考虑轮轨间黏着力变化指标和牵引电机转矩波动指标的加权目标函数;... 为解决机车牵引过程中轮轨间最优黏着利用能否获得的问题,提出一种基于高斯RBF神经网络的机车黏着智能优化控制方法。针对黏着极限态优化控制效果的定量评估,定义了同时考虑轮轨间黏着力变化指标和牵引电机转矩波动指标的加权目标函数;提出动态多子群GSA算法以优化RBFNN参数,避免了参数选择的盲目性,提高了RBFNN的收敛速度和学习能力;此外,该方法不依赖被控对象的解析模型,仅基于系统输入、输出信息完成控制器设计,并通过对电机转矩的动态调整,实现轮轨间黏着的最优利用。仿真结果验证了该方法的正确性和有效性。 展开更多
关键词 机车黏着智能优化控制 加权目标函数 高斯RBF神经网络 动态多子群GSA算法
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考虑多失效模式的桩-土结构体系稳健性设计 被引量:4
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作者 杜修力 曹秀秀 +2 位作者 钟紫蓝 侯本伟 王威 《中国安全科学学报》 CAS CSCD 北大核心 2020年第6期23-30,共8页
针对桩基础设计中岩土参数和荷载的不确定性,首先,提出考虑多失效模式的桩-土结构体系的稳健性设计(RGD)方法,综合分析单桩竖向承载能力极限状态(ULS)、竖向正常使用极限状态(SLS)、水平强度失效和水平变形失效4种失效模式;其次,采用蒙... 针对桩基础设计中岩土参数和荷载的不确定性,首先,提出考虑多失效模式的桩-土结构体系的稳健性设计(RGD)方法,综合分析单桩竖向承载能力极限状态(ULS)、竖向正常使用极限状态(SLS)、水平强度失效和水平变形失效4种失效模式;其次,采用蒙特卡罗模拟(MCS)法和点估计法(PEM)嵌套的方法计算桩-土结构体系的失效概率均值和标准差,以失效概率标准差作为衡量结构稳健性的指标;最后,以稳健性和经济成本作为优化目标,确定单桩的最优设计。结果表明:多失效模式下,不同的单桩设计尺寸,起决定作用的失效模式不同;随着单桩设计几何尺寸的增加,桩-土结构体系的主控失效模式逐渐由桩水平强度控制转为由竖向正常使用极限状态控制;主控失效模式的变化,对结构体系的失效概率变化梯度影响较大。 展开更多
关键词 -土结构体系 多失效模式 可靠度分析 稳健性设计(RGD) 多目标优化
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飞机整体结构件的“加工变形-疲劳寿命”多目标结构优化方法 被引量:9
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作者 秦国华 郭翊翔 +2 位作者 王华敏 侯源君 娄维达 《工程力学》 EI CSCD 北大核心 2021年第8期222-236,共15页
在毛坯制造过程中,材料力学性能的非均匀性导致铝合金厚板内产生残余应力,以致在后续的高速切削加工过程中,随着材料的大量去除,残余应力的释放使得整体结构件发生变形,严重影响着整体结构件的尺寸稳定性。因此,研究零件结构与零件变形... 在毛坯制造过程中,材料力学性能的非均匀性导致铝合金厚板内产生残余应力,以致在后续的高速切削加工过程中,随着材料的大量去除,残余应力的释放使得整体结构件发生变形,严重影响着整体结构件的尺寸稳定性。因此,研究零件结构与零件变形之间的关系对于实现加工过程的高效化和精密化至关重要。首先,将铝厚板内残余应力的释放合理地等效为外载荷的施加,利用材料力学弯曲变形公式建立铝厚板在厚度方向上加工变形的挠度模型。由实际加工测量可知:加工变形的公式解析值、有限元仿真值与实际测量值吻合得很好。为了进一步分析零件结构与疲劳寿命之间的关系,通过名义应力法对零件的最小疲劳寿命与疲劳载荷下零件的最大应力进行等效以简化分析,对部分具有代表性的结构进行静力分析后将其作为样本进行神经网络拟合,得到了以3个腹板位置为输入、零件最大加工变形及最大疲劳应力为输出的神经网络模型。最后利用神经网络模型构建了一个使得最大加工变形和最大疲劳应力都尽可能小的多目标优化问题,使用遗传算法求解该多目标问题后取得的最优解为:3个腹板与零件底部距离分别为8.868 mm、27.992 mm、28.000 mm,此时零件的最大加工变形为0.088 mm,最小的随机疲劳载荷寿命为4.432×10^(7)次。 展开更多
关键词 初始残余应力 加工变形 疲劳分析 名义应力法 航空整体结构件 多目标结构优化
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