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multi-objective optimization of a mixed-flow pump impeller using modified NSGA-II algorithm

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Science China(Technological Sciences) 2015年第12期58卷 2122-2130页

作者： HUANG RenFang LUO XianWu JI Bin WANG Peng YU An ZHAI ZhiHong ZHOU JiaJian State Key Laboratory of Hydroscience and Engineering Tsinghua University School of Power and Mechanical Engineering Wuhan University Advanced Design Technology Marine Design and Research Institute of China

In order to maintain a uniform distribution of pareto-front solutions, a modified NSGA-II algorithm coupled with a dynamic crowding distance(DCD) method is proposed for the multi-objective optimization of a mixed-flow pump impeller. With the pump meridional section fixed, ten variables along the shroud and hub are selected to control the blade load by using a three-dimensional inverse design method. Hydraulic efficiency, along with impeller head, is applied as an optimization objective; and a radial basis neural network(RBNN) is adopted to approximate the objective function with 82 training samples. Local sensitivity analysis shows that decision variables have different impacts on the optimization objectives. Instead of randomly selecting one solution to implement, a technique for ordering preferences by similarity to ideal solution(TOPSIS) is introduced to select the best compromise solution(BCS) from pareto-front sets. The proposed method is applied to optimize the baseline model, i.e. a mixed- flow waterjet pump whose specific speed is 508 min?1?m3s?1?m. The performance of the waterjet pump was experimentally tested. Compared with the baseline model, the optimized impeller has a better hydraulic efficiency of 92% as well as a higher impeller head at the design operation point. Furthermore, the off-design performance is improved with a wider highefficiency operation range. After optimization, velocity gradients on the suction surface are smoother and flow separations are eliminated at the blade inlet part. Thus, the authors believe the proposed method is helpful for optimizing the mixed-flow pumps.

关键词： mixed-flow pump waterjet pump multi-objective optimization numerical simulation modified NSGA-II

multi-objective optimization design of bridge piers with hybrid heuristic algorithms

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第6期13卷 420-432页

作者： Francisco J. MARTINEZ-MARTIN Fernando GONZALEZ-VIDOSA Antonio HOSPITALER Víctor YEPES Department of Geotechnical Engineering Universitat Politècnica de València 46022 Valencia Spain Department of Construction Engineering ICITECH Universitat Politècnica de València 46022 Valencia Spain

This paper describes one approach to the design of reinforced concrete (RC) bridge piers, using a three-hybrid multi- objective simulated annealing (SA) algorithm with a neighborhood move based on the mutation operator from the genetic algorithms (GAs), namely MOSAMO1, MOSAMO2 and MOSAMO3. The procedure is applied to three objective functions: the economic cost, the reinforcing steel congestion and the embedded CO 2 emissions. Additional results for a random walk and a descent local search multi-objective algorithm are presented. The evaluation of solutions follows the Spanish Code for structural concrete. The methodology was applied to a typical bridge pier of 23.97 m in height. This example involved 110 design variables. Results indicate that algorithm MOSAMO2 outperforms other algorithms regarding the definition of Pareto fronts. Further, the proposed procedure will help structural engineers to enhance their bridge pier designs.

关键词： Bridge piers Concrete structures multi-objective optimization Simulated annealing (SA) Structural design

multi-objective optimization for task offloading based on network calculus in fog environments

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Digital Communications and Networks 2022年第5期8卷 825-833页

作者： Qian Ren Kui Liu Lianming Zhang College of Information Science and Engineering Hunan Normal UniversityChangsha410081China

With the widespread application of wireless communication technology and continuous improvements to Internet of Things(IoT)technology,fog computing architecture composed of edge,fog,and cloud layers have become a research *** architecture uses Fog Nodes(FNs)close to users to implement certain cloud functions while compensating for cloud ***,because of the limited computing and storage capabilities of a single FN,it is necessary to offload tasks to multiple cooperating FNs for task *** effectively and quickly realize task offloading,we use network calculus theory to establish an overall performance model for task offloading in a fog computing environment and propose a Globally Optimal multi-objective optimization algorithm for Task Offloading(GOMOTO)based on the performance *** results show that the proposed model and algorithm can effectively reduce the total delay and total energy consumption of the system and improve the network Quality of Service(QoS).

关键词： Fog computing Task offloading multi-objective optimization Network calculus

multi-objective optimization of thermochromic glazing based on daylight and energy performance evaluation

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Building Simulation 2021年第6期14卷 1685-1695页

作者： Xiaoqiang Hong Feng Shi Shaosen Wang Xuan Yang Yue Yang School of Architecture and Civil Engineering Xiamen UniversityXiamen361005China School of Mechanical Engineering and Automation Harbin Institute of TechnologyShenzhen518055China

Many efforts have been detected to investigate thermochromic(TC)glazing for improving building energy saving,while only a few approaches for daylight performance *** this study,the performance of TC glazing is investigated based on multi-objective optimization for minimizing energy demand while maximizing daylight *** effects of five parameters including transition temperature,solar transmittance in clear state,solar transmittance modulation ability,luminous transmittance in clear state,and luminous modulation ability on the building energy consumption and useful daylighting illuminance(UDI_(300-3000))are *** Programming Technique for multi-dimensional Analysis of Preference(LINMAP)is used for the decision-making of Pareto *** research aims to explore the ideal thermochromic glazing by considering the daylight and energy performance of a typical office room,taking the weather condition of Xiamen,China as an *** it is impossible to achieve both optimal values of energy consumption and UDI_(300-3000)simultaneously,the proposed multi-objective optimization method could still provide low energy consumption with sufficient *** non-dominated sorting of Pareto optimal solution(POS)demonstrated that the optimum building energy consumption and UDI_(300-3000)for single glazed windows are 46.64 kWh/m^(2)and 70.92%,respectively,while the values for double glazed windows are 44.40 kWh/m^(2)and 71.88%,*** selected hypothetical TC windows can improve the building energy and daylighting performance simultaneously when compared with traditional clear single and double glazed *** presented framework provides a multi-objective optimization method to determine the most suitable TC glazing technologies for designers and architects during the design and retrofit procedure.

关键词： thermochromic transition temperature daylighting building energy performance multi-objective optimization

multi-objective optimization of a Parallel Ankle Rehabilitation Robot Using Modified Differential Evolution Algorithm

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Chinese Journal of Mechanical Engineering 2015年第4期28卷 702-715页

作者： WANG Congzhe FANG Yuefa GUO Sheng School of Mechanical Electronic and Control Engineering Beijing Jiaotong University

Dimensional synthesis is one of the most difficult issues in the field of parallel robots with actuation redundancy. To deal with the optimal design of a redundantly actuated parallel robot used for ankle rehabilitation, a methodology of dimensional synthesis based on multi-objective optimization is presented. First, the dimensional synthesis of the redundant parallel robot is formulated as a nonlinear constrained multi-objective optimization problem. Then four objective functions, separately reflecting occupied space, input/output transmission and torque performances, and multi-criteria constraints, such as dimension, interference and kinematics, are defined. In consideration of the passive exercise of plantar/dorsiflexion requiring large output moment, a torque index is proposed. To cope with the actuation redundancy of the parallel robot, a new output transmission index is defined as well. The multi-objective optimization problem is solved by using a modified Differential Evolution（DE） algorithm, which is characterized by new selection and mutation strategies. Meanwhile, a special penalty method is presented to tackle the multi-criteria constraints. Finally, numerical experiments for different optimization algorithms are implemented. The computation results show that the proposed indices of output transmission and torque, and constraint handling are effective for the redundant parallel robot; the modified DE algorithm is superior to the other tested algorithms, in terms of the ability of global search and the number of non-dominated solutions. The proposed methodology of multi-objective optimization can be also applied to the dimensional synthesis of other redundantly actuated parallel robots only with rotational movements.

关键词： ankle rehabilitation parallel robot multi-objective optimization differential evolution algorithm

multi-objective optimization of space station short-term mission planning

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Science China(Technological Sciences) 2015年第12期58卷 2169-2185页

作者： BU HuiJiao ZHANG Jin LUO YaZhong ZHOU JianPing College of Aerospace Science and Engineering National University of Defense Technology Chinese Manned Space Engineering Office

This paper studies the multi-objective optimization of space station short-term mission planning(STMP), which aims to obtain a mission-execution plan satisfying multiple planning demands. The planning needs to allocate the execution time effectively, schedule the on-board astronauts properly, and arrange the devices reasonably. The STMP concept models for problem definitions and descriptions are presented, and then an STMP multi-objective planning model is developed. To optimize the STMP problem, a Non-dominated Sorting Genetic Algorithm II(NSGA-II) is adopted and then improved by incorporating an iterative conflict-repair strategy based on domain knowledge. The proposed approach is demonstrated by using a test case with thirty-five missions, eighteen devices and three astronauts. The results show that the established STMP model is effective, and the improved NSGA-II can successfully obtain the multi-objective optimal plans satisfying all constraints considered. Moreover, through contrast tests on solving the STMP problem, the NSGA-II shows a very competitive performance with respect to the Strength Pareto Evolutionary Algorithm II(SPEA-II) and the multi-objective Particle Swarm optimization(MOPSO).

关键词： space station short-term mission planning multi-objective optimization NSGA-II

multi-objective optimization design of deviation-correction trajectory considering the production loss in shale gas cluster well

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Petroleum Science 2022年第6期19卷 2995-3003页

作者： Zi-Jun Dou Yong-Sheng Liu Xing Qin De-Li Gao Gan-Sheng Yang Key Laboratory of Deep Geological Drilling Technology of Ministry of Natural Resources China University of GeosciencesBeijing 100083China Sinopec Research Institute of Petroleum Engineering Beijing 100101China MOE Key Lab of Petroleum Engineering China University of PetroleumBeijing 102249China

In shale gas mining,the inter-fracture interference effect will significantly occur if the actual well deviates from the planned *** reduce production loss,operators want to get back on the planned trajectory economically and *** on this,a multi-objective optimization model of deviationcorrection trajectory is established considering the production loss ***,the functional relationship between the production envelope and the fracturing depth is constructed,and the production loss is obtained by combining the calculation method of volume *** on the proposed“double-arc”trajectory design method,the production loss of the fracture on the deviation-correction trajectory is ***,combined with the well profile energy evaluation,a new optimization model of deviation-correction trajectory is *** results demonstrate that after optimizing the fracturing depth,the production loss of the deviation-correction trajectory is reduced by 13.2%.The maximum curvature value results in a trajectory with a minimum production loss yet a maximum well profile *** proposed model reduces the well profile energy by 15.6%compared with the existing *** is proved that the proposed model can reduce the probability of drilling accidents and achieve high gas production in the later mining *** study fully considers various factors affecting horizontal wells in the fracturing area,which can provide theoretical guidance for the design of deviationcorrection trajectory.

关键词： Shale gas Inter-fracture interference effect Production loss Deviation-correction trajectory multi-objective optimization

multi-objective optimization of EV Charging and Discharging for Different Stakeholders

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CSEE Journal of Power and Energy Systems 2023年第6期9卷 2301-2308页

作者： Shaofeng Lu Bing Han Fei Xue Lin Jiang Kejun Qian the Shien-Ming Wu School of Intelligent Engineering South China University of TechnologyGuangzhou 511442China the Department of Electrical and Electronic Engineering School of Advanced TechnologyXi'an Jiaotong-Liverpool UniversitySuzhou 215123China the Department of Electrical Engineering and Electronics University of LiverpoolLiverpoolUK Suzhou Power Supply Company State Grid Corporation of ChinaSuzhou 215000China

As a dynamic energy storage system,electric vehicles(EV)play important roles in future power *** this paper,a model for EV aggregator participation in the electricity market has been built with a focus on the feasibility issue of the model arising from economic interest inconsistencies between different stakeholders:EV owners and *** the model,the EV aggregator attends day-ahead energy and reserve markets for profit maximization by scheduling charging and discharging behaviors of *** issue exists since different stakeholders have different interests which are not necessarily consistent,*** maximization leads to increasing EV owners'charging *** investigate the economic relationship between the two stakeholders,two multi-objective optimization methods(weighted sum and$\varepsilon$-constraint methods)are proposed to take the aggregator profit and EV owners'charging fee into account in the model.A sensitivity analysis is applied to examine the aggregator profit under different price scenarios,which reveals the internal relationship between EV owners'charging fees and aggregator *** proposed EV charging and discharging strategy in this paper could be used to determine the settlement price between the aggregator and owners to ensure the feasibility of participation from both EV owners and stakeholders in electricity markets.

关键词： Aggregator economic inconsistency issue electricity market EV owners EV multi-objective optimization

multi-objective optimization of Industrial Purified Terephthalic Acid Oxidation Process

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Chinese Journal of Chemical Engineering 2003年第5期11卷 536-541页

作者：牟盛静苏宏业古勇褚健 National Laboratory of Industrial Control Technology Institute of Advanced Process Control Zhejiang UniversityHangzhou 310027 China

multi-objective optimization of a purified terephthalic acid (PTA) oxidation unit is carried out in this paper by using a process modei that has been proved to describe industrial process quite well. The modei is a semi-empirical structured into two series ideal continuously stirred tank reactor (CSTR) models. The optimal objectives include maximizing the yield or inlet rate and minimizing the concentration of 4-carboxy-benzaldhyde, which is the main undesirable intermediate product in the reaction process. The multi-objective optimization algorithra applied in this study is non-dominated sorting genetic algorithm Ⅱ (NSGA-Ⅱ). The performance of NSGA-Ⅱ is further illustrated by application to the title process.

关键词： multi-objective optimization purified terephthalic acid oxidation process non-dominated sorting genetic algorithm Ⅱ