ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

An optimization model for gravity treetype pipe network is established, in whi ch the minimal investment is taken as the objective function, and the pressu re, flow rate and pipe diameter are taken as the constraint conditions. The impr oved genetic algorithm is used to solve the problem. Based on the optimal featur es of treetype pipe network, the dual coding combining binary coding with inte ger coding is adopted in the genetic algorithm to optimize the pipe layout and p ipe diameter simultaneously. Based on characteristics of tree in the graph theor y, the cycle method is adopted to improve cross method in the operations of init ial solution creating and mutation so that the number of infeasible solutions is reduced. Some operational processes of genetic algorithm are improved. The simu lated annealing algorithm is introduced in the model. The fitness function is ad justed, and the computing methods of crossover rate and mutation rate are improv ed. Example shows that the algorithm is efficient.