The goal of this effort was to provide a static and dynamic collaborative optimization （CO） model for the design of ship hull structure. The CO model integrated with static, mode and dynamic analyses. In the system-...The goal of this effort was to provide a static and dynamic collaborative optimization （CO） model for the design of ship hull structure. The CO model integrated with static, mode and dynamic analyses. In the system-level optimization model, a new objective function was advised, integrating all the subsystem-levels＇ objective functions, so as to eliminate the effects of dimensions and magnitude order. The proposed CO architecture enabled multi-objectives of the system and subsystem-level to be considered at both levels during optimization. A bi-level optimization strategy was advised, using the multi-island genetic algorithm. The proposed model was demonstrated with a deck optimization problem of container ship stern. The analysis progress and results of example show that the CO strategy is not only feasible and reliable, but also well suited for use in actual optimization problems of ship design.展开更多
Genetic diversity and genetic differentiation of natural populations of Pinus kesiya var. langbinanensis were examined by means of electrophoresis technique. Analysis of 9 enzyme systems including 16 loci showed that ...Genetic diversity and genetic differentiation of natural populations of Pinus kesiya var. langbinanensis were examined by means of electrophoresis technique. Analysis of 9 enzyme systems including 16 loci showed that all the three natural popu-lations of the pine were high in genetic diversity but low in inter-population genetic differentiation. The proportion of polymorphic loci is 0.667, with each locus holding 2.13 alleles, averagely. The average expected and observed heterozygosity was 0.288 and 0.197, respectively. The gene differentiation among populations was 0.052, but the mean genetic distance was only 0.015.展开更多
Allozymes of eleven species of Megophryinae in China were examined electrophoretically to investigate genetic diversity and phylogenetic relationships. Fourteen enzymes, presumptively coded by 24 loci were detected to...Allozymes of eleven species of Megophryinae in China were examined electrophoretically to investigate genetic diversity and phylogenetic relationships. Fourteen enzymes, presumptively coded by 24 loci were detected to be variable. Gene frequencies of each population at each locus were presented. The commonly used measure of genetic diversity, the average heterozygosity (H) were calculated based on gene frequencies. The results indicated that Megophryinae had a high level of genetic diversity in amphibians, an average H of 0.18, ranging from 0.058 to 0.28. Nei's (1978) genetic distances(Nei's D) were calculated for all possible population pairs. A dendrogram of 13 populations representing 11 species, 3 genera of Megophryinae were derived and presented by using UPGMA, based on Nei' s D. The assignment of Ophryophryne as a distinct genus were supported by an average Nei's D of 1.4067 which separated O. microstoma from all other populations.Subdivision of Brachytarsophrys from Megophrys was not supported by this study. Within Megophrys, three groups were recognized: (1)M. lateralis, M. giganticus and M. longipes; (2)M. palpebralespineosa, M. boettgeri and M. parva;(3) M. minor and M. kuatunensis. Three populations of M. omeimontis were closely related and share a clade independent from all other Megophrys, and B. feae as well.展开更多
To address the issue of premature convergence and slow convergence rate in three-dimensional (3D) route planning of unmanned aerial vehicle (UAV) low-altitude penetration,a novel route planning method was proposed.Fir...To address the issue of premature convergence and slow convergence rate in three-dimensional (3D) route planning of unmanned aerial vehicle (UAV) low-altitude penetration,a novel route planning method was proposed.First and foremost,a coevolutionary multi-agent genetic algorithm (CE-MAGA) was formed by introducing coevolutionary mechanism to multi-agent genetic algorithm (MAGA),an efficient global optimization algorithm.A dynamic route representation form was also adopted to improve the flight route accuracy.Moreover,an efficient constraint handling method was used to simplify the treatment of multi-constraint and reduce the time-cost of planning computation.Simulation and corresponding analysis show that the planning results of CE-MAGA have better performance on terrain following,terrain avoidance,threat avoidance (TF/TA2) and lower route costs than other existing algorithms.In addition,feasible flight routes can be acquired within 2 s,and the convergence rate of the whole evolutionary process is very fast.展开更多
表观遗传学对于很多高中生物教师而言,是个全新的概念,也是目前生物学研究的一个热点。鉴于此,本文简单地介绍表观遗传学的提出者——沃丁顿,希望能通过对这位科学家成长背景的介绍,促进各位同仁对表观遗传学的认识。1沃丁顿的生平简介...表观遗传学对于很多高中生物教师而言,是个全新的概念,也是目前生物学研究的一个热点。鉴于此,本文简单地介绍表观遗传学的提出者——沃丁顿,希望能通过对这位科学家成长背景的介绍,促进各位同仁对表观遗传学的认识。1沃丁顿的生平简介沃丁顿(图1),其英文名为C.H.Waddington,全称为Conrad Hal Waddington。展开更多
基金Knowledge-based Ship-design Hyper-integrated Platform(KSHIP) of Ministry of Education and Ministry of Finance,P. R. China(No.200512)
文摘The goal of this effort was to provide a static and dynamic collaborative optimization （CO） model for the design of ship hull structure. The CO model integrated with static, mode and dynamic analyses. In the system-level optimization model, a new objective function was advised, integrating all the subsystem-levels＇ objective functions, so as to eliminate the effects of dimensions and magnitude order. The proposed CO architecture enabled multi-objectives of the system and subsystem-level to be considered at both levels during optimization. A bi-level optimization strategy was advised, using the multi-island genetic algorithm. The proposed model was demonstrated with a deck optimization problem of container ship stern. The analysis progress and results of example show that the CO strategy is not only feasible and reliable, but also well suited for use in actual optimization problems of ship design.
基金his article was supported by the Natural Science Founda-tion of Yunnan Province (No.98C017Q).
文摘Genetic diversity and genetic differentiation of natural populations of Pinus kesiya var. langbinanensis were examined by means of electrophoresis technique. Analysis of 9 enzyme systems including 16 loci showed that all the three natural popu-lations of the pine were high in genetic diversity but low in inter-population genetic differentiation. The proportion of polymorphic loci is 0.667, with each locus holding 2.13 alleles, averagely. The average expected and observed heterozygosity was 0.288 and 0.197, respectively. The gene differentiation among populations was 0.052, but the mean genetic distance was only 0.015.
基金This work was financially supported by Natural Science Foundation of China.
文摘Allozymes of eleven species of Megophryinae in China were examined electrophoretically to investigate genetic diversity and phylogenetic relationships. Fourteen enzymes, presumptively coded by 24 loci were detected to be variable. Gene frequencies of each population at each locus were presented. The commonly used measure of genetic diversity, the average heterozygosity (H) were calculated based on gene frequencies. The results indicated that Megophryinae had a high level of genetic diversity in amphibians, an average H of 0.18, ranging from 0.058 to 0.28. Nei's (1978) genetic distances(Nei's D) were calculated for all possible population pairs. A dendrogram of 13 populations representing 11 species, 3 genera of Megophryinae were derived and presented by using UPGMA, based on Nei' s D. The assignment of Ophryophryne as a distinct genus were supported by an average Nei's D of 1.4067 which separated O. microstoma from all other populations.Subdivision of Brachytarsophrys from Megophrys was not supported by this study. Within Megophrys, three groups were recognized: (1)M. lateralis, M. giganticus and M. longipes; (2)M. palpebralespineosa, M. boettgeri and M. parva;(3) M. minor and M. kuatunensis. Three populations of M. omeimontis were closely related and share a clade independent from all other Megophrys, and B. feae as well.
基金Project(60925011) supported by the National Natural Science Foundation for Distinguished Young Scholars of ChinaProject(9140A06040510BQXXXX) supported by Advanced Research Foundation of General Armament Department,China
文摘To address the issue of premature convergence and slow convergence rate in three-dimensional (3D) route planning of unmanned aerial vehicle (UAV) low-altitude penetration,a novel route planning method was proposed.First and foremost,a coevolutionary multi-agent genetic algorithm (CE-MAGA) was formed by introducing coevolutionary mechanism to multi-agent genetic algorithm (MAGA),an efficient global optimization algorithm.A dynamic route representation form was also adopted to improve the flight route accuracy.Moreover,an efficient constraint handling method was used to simplify the treatment of multi-constraint and reduce the time-cost of planning computation.Simulation and corresponding analysis show that the planning results of CE-MAGA have better performance on terrain following,terrain avoidance,threat avoidance (TF/TA2) and lower route costs than other existing algorithms.In addition,feasible flight routes can be acquired within 2 s,and the convergence rate of the whole evolutionary process is very fast.
文摘表观遗传学对于很多高中生物教师而言,是个全新的概念,也是目前生物学研究的一个热点。鉴于此,本文简单地介绍表观遗传学的提出者——沃丁顿,希望能通过对这位科学家成长背景的介绍,促进各位同仁对表观遗传学的认识。1沃丁顿的生平简介沃丁顿(图1),其英文名为C.H.Waddington,全称为Conrad Hal Waddington。
