首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   6篇
工业技术   6篇
  2016年   1篇
  2015年   1篇
  2013年   1篇
  2011年   1篇
  2006年   1篇
  1998年   1篇
排序方式: 共有6条查询结果,搜索用时 93 毫秒
1
1.
One of the main objectives in tolerance charting is to determine the working dimensions and tolerances at the lowest cost without violating the blueprint specifications. It is with this objective in mind that the authors present a comprehensive study of the effect of the choice of an objective function on the final manufacturing cost. Optimisation of the objective functions has been done using PROFORT (nonlinear optimisation). The paper deals with a single example, solved using two linear and a nonlinear objective function.  相似文献   
2.
遗传算法中适应度函数的研究   总被引:5,自引:0,他引:5  
通过分析遗传算法中常见的几种适应度函数的不足,论证了适应度函数在遗传算法中的重要性,提出了设计适应度函数应满足的标准,在此基础上给出了一适应度函数公式.实验结果表明:此适应度函数的性能明显优于其它函数,对提高遗传算法的整体性能也有重要意义.  相似文献   
3.
基于生态毒理动力学模型构造出可全局收敛的函数优化算法. 在该算法中,将优化问题的搜索空间看成一个存在污染现象的环境系统,将一个试探解看成一个种群,采用生态毒理动力学模型对种群生长特征的变化规律进行描述. 种群在污染作用下不断发生变化,能够抵抗住污染的强壮种群能够获得生长,而无法抵抗住污染的虚弱种群则停止生长. 用环境和种群以及种群与种群之间的相互作用关系构造进化算子,这些算子从多种角度实现了种群之间的信息交换. 因环境污染影响的是种群的很少部分特征,当种群演化时,只涉及到很少一部分种群特征参与运算,故提高了算法的收敛速度. 测试结果表明本算法的精度和性能优于已有的群智能优化算法.  相似文献   
4.
借鉴生物免疫系统的克隆选择机制,利用生物工程中基因重组技术,提出一种基于基因重组的克隆选择算法。根据抗体亲和力大小对抗体进行选择,获取优秀抗体的优秀基因片段,对抗体进行不同程度的基因重组,实现高频变异过程中的定向控制,避免种群退化,加快收敛速度,提高全局搜索范围,防止局部收敛。通过对复杂函数优化问题的仿真实验表明,基于基因重组的克隆选择算法(GRCSA)具有良好的收敛速度和较高的问题解的精度,证明新算法的有效性。  相似文献   
5.
This work deals with the problem of model performance evaluation, which is a challenge in many science branches, including subsurface fluid flow modelling (e.g. reservoir characterisation using history matching algorithms).The issue is posed as a problem of estimating the model performance by comparing the simulation results with observed data. This is accomplished by defining different statistical indicator objective functions (OF) to calculate the model efficiency, i.e. how model simulation fits observed data.Several deviation-based statistics used in literature as OF are analysed and applied to two synthetic case studies related to fluid flow in reservoir. Inaccuracies that arise from using the deviation-based statistics are discussed in a comparative way to propose an appropriate approach to boost the model accuracy when selecting the best realisation from multiple equally realisations generated during the history matching algorithm.The evaluations reveal that the suitable approach requires the adoption of an OF, that combines lag time with deviation-based statistic (SSR), to enhance the history matching process. The proposed approach has proven robust in the sense that it is able to provide an accurate and faster history matching algorithm for reservoir characterisation.  相似文献   
6.
The unmanned aerial vehicle (UAV) path planning problem is an important assignment in the UAV mission planning. Based on the artificial potential field (APF) UAV path planning method, it is reconstructed into the constrained optimisation problem by introducing an additional control force. The constrained optimisation problem is translated into the unconstrained optimisation problem with the help of slack variables in this paper. The functional optimisation method is applied to reform this problem into an optimal control problem. The whole transformation process is deduced in detail, based on a discrete UAV dynamic model. Then, the path planning problem is solved with the help of the optimal control method. The path following process based on the six degrees of freedom simulation model of the quadrotor helicopters is introduced to verify the practicability of this method. Finally, the simulation results show that the improved method is more effective in planning path. In the planning space, the length of the calculated path is shorter and smoother than that using traditional APF method. In addition, the improved method can solve the dead point problem effectively.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号