The rank-sum test is a nonparametric method used in variety evaluation.However,the hypothesis testing of the method hasn't been established for multi-trait comprehensive ranking.In this paper,under null hypothesis...The rank-sum test is a nonparametric method used in variety evaluation.However,the hypothesis testing of the method hasn't been established for multi-trait comprehensive ranking.In this paper,under null hypothesis H0:the variety's ranking on each trait is random,the theoretical distribution of sum of ranks(SR) was firstly derived and further used to obtain the critical values for multi-trait comprehensive evaluation in rank-sum testing.A new C++ class and its basic arithmetic were defined to deal with the miscount caused by the precision limitation of built-in data type in common statistical software under large number of varieties and traits.Finally,an application of the theoretical results was demonstrated using five starch viscosity traits of 12 glutinous maize varieties.The proposed method is so simple and convenient that it can be easily used to rank different varieties by multiple traits.展开更多
Natural frequency and dynamic stiffness under transient loading are two key performances for structural design related to automotive,aviation and construction industries.This article aims to tackle the multi-objective...Natural frequency and dynamic stiffness under transient loading are two key performances for structural design related to automotive,aviation and construction industries.This article aims to tackle the multi-objective topological optimization problem considering dynamic stiffness and natural frequency using modified version of bi-directional evolutionary structural optimization(BESO).The conventional BESO is provided with constant evolutionary volume ratio(EVR),whereas low EVR greatly retards the optimization process and high EVR improperly removes the efficient elements.To address the issue,the modified BESO with variable EVR is introduced.To compromise the natural frequency and the dynamic stiffness,a weighting scheme of sensitivity numbers is employed to form the Pareto solution space.Several numerical examples demonstrate that the optimal solutions obtained from the modified BESO method have good agreement with those from the classic BESO method.Most importantly,the dynamic removal strategy with the variable EVR sharply springs up the optimization process.Therefore,it is concluded that the modified BESO method with variable EVR can solve structural design problems using multi-objective optimization.展开更多
基金supported by the National Key Basic Research Program of China(2006CB101700)the Program for New Century Excellent Talents in University of Ministry of Education of China(NCET2005-05-0502)
文摘The rank-sum test is a nonparametric method used in variety evaluation.However,the hypothesis testing of the method hasn't been established for multi-trait comprehensive ranking.In this paper,under null hypothesis H0:the variety's ranking on each trait is random,the theoretical distribution of sum of ranks(SR) was firstly derived and further used to obtain the critical values for multi-trait comprehensive evaluation in rank-sum testing.A new C++ class and its basic arithmetic were defined to deal with the miscount caused by the precision limitation of built-in data type in common statistical software under large number of varieties and traits.Finally,an application of the theoretical results was demonstrated using five starch viscosity traits of 12 glutinous maize varieties.The proposed method is so simple and convenient that it can be easily used to rank different varieties by multiple traits.
基金Foundation item： Supported by the National Natural Science Foundation of China（10671057） Supported by the Natural Science Foundation of Henan Institute of Science and Technology（06054）
基金funded by the National Natural Science Foundation of China(Grant No.51505096)the Natural Science Foundation of Heilongjiang Province(Grant No.LH2020E064).
文摘Natural frequency and dynamic stiffness under transient loading are two key performances for structural design related to automotive,aviation and construction industries.This article aims to tackle the multi-objective topological optimization problem considering dynamic stiffness and natural frequency using modified version of bi-directional evolutionary structural optimization(BESO).The conventional BESO is provided with constant evolutionary volume ratio(EVR),whereas low EVR greatly retards the optimization process and high EVR improperly removes the efficient elements.To address the issue,the modified BESO with variable EVR is introduced.To compromise the natural frequency and the dynamic stiffness,a weighting scheme of sensitivity numbers is employed to form the Pareto solution space.Several numerical examples demonstrate that the optimal solutions obtained from the modified BESO method have good agreement with those from the classic BESO method.Most importantly,the dynamic removal strategy with the variable EVR sharply springs up the optimization process.Therefore,it is concluded that the modified BESO method with variable EVR can solve structural design problems using multi-objective optimization.
