In view of the shortcomings of the traditional basic differential evolution algorithm:the algorithm is too sensitive to parameter settings and the algorithm is easy to fall into precocious convergence and weak stabil-ity,this paper proposes improvement measures,and adopts a symmetry algorithm to maintain population diversity,and effectively compete with mutated individuals,symmetric individuals,and individuals,so as to enhance the global search ability of the algorithm.At the same time,the selection strategy of roulette and the quadratic muta-tion operator are used to ensure the effectiveness and diversity of individuals in the population,and to increase the global stability of the algorithm.The algorithm in this paper is applied to solve the problem of capital decision allocation,and through simulation,the algorithm is better than other compared algorithms in terms of stability,convergence speed and solution accuracy.
近年来随着简牍材料的大量刊布,简牍学研究呈现出繁荣景象.与此相应,在高校开设简牍学课程是十分必要的.当前的高等教育中,历史学专业本科阶段开设简牍学课程远不及研究生阶段普遍.鉴于一般历史学本科生的知识储备结构,在已有考古学课程基础上,为其开设简牍学课程仍是很必要的.该课程可依次以总论性专题、各批简牍的介绍与研读、简牍材料的具体利用三大部分展开.在备课、授课过程中,还应特别注意课程的现实性、趣味性、立体性和前沿性,以取得更好的课堂效果.
运用熵值法测算了2010-2020 年河南省各地市基本公共服务水平,使用Dagum基尼系数分解法分析了地区差异,进而检验其σ收敛和β收敛特征.研究发现,河南省整体和各市基本公共服务水平稳步提高,"十一五"、"十二五"和"十三五"期末各城市水平在全省中相对位置变化不大.全省基本公共服务水平总体相对差异先增大后减小,总体差异最大来源于区域间差异,超变密度次之,区域内差异贡献最小.其中,豫中区域内差异最大,豫西地区最小.关于收敛特征,除豫北和豫中地区,全省和省内其他地区均存在σ收敛;而全省和省内五大区域均存在绝对β收敛和相对β收敛,研究加深了对河南省基本公共服务供给水平空间差异的认识.
