手征媒质反射特性仿真计算

手征媒质是双各向同性媒质的一种,其手征参数具有可调性。首先,在标准粒子群 算法(PSO)和模拟退火（SA）算法的基础上进行了改进,并利用混合算法优化设计手征参数 及媒质 厚度,以在给定的频率范围内获得较高的吸收率。然后,仿真计算了某一个参数取不同值而 其它参数固定情况下电磁波垂直入射到手征媒质时的反射系数。结果证明,只有在最优化参 数条件下才可以在频带内获得较理想的吸收率和反射系数。     

A metaheuristic approach to the reliable location routing problem under disruptions

This paper examines a reliable capacitated location–routing problem in which depots are randomly disrupted. Customers whose depots fail must be reinserted into the routes of surviving depots. We present a scenario-based mixed-integer programming model to optimize depot location, outbound delivery routing, and backup plans. We design a metaheuristic algorithm that is based on a maximum-likelihood sampling method, route-reallocation improvement, two-stage neighborhood search and simulated annealing. Numerical tests show that the heuristic is able to generate results that would keep operating costs and failure costs well balanced. Managerial insights on scenario identification, facility deployment and model simplification are drawn.     

Integrated inventory-transportation model by synchronizing delivery and production cycles

This paper develops an integrated single-vendor multi-buyer inventory-transportation synchronized supply chain model. In this paper, the decisions of truck assignment and routing are also considered and as a result, a series of vehicle routing problems (VRP) are required to be solved. Due to the highly complicated objective function and the NP-hard VRP problems, the problem cannot be solved analytically. Hence, meta-heuristics are proposed. By means of the numerical examples and a case study, the meta-heuristics developed are shown to be very effective in solving such comprehensive supply chain models, and the results so obtained are promising.     

模拟退火算法在压缩天然气加气站选址中的应用

压缩天然气(CNG)加气站选址对CNG汽车的发展有重要影响,合理的加气站选址能使加气站以较低的运输费用为尽可能多的CNG汽车提供加气服务,使项目有较高盈利水平,为此,构造了一个CNG加气站最大收益选址模型,通过求解该模型,可以为CNG加气站项目管理者提供一个最优或者近似最优的选址方案。     

Modelling research and development: How do firms solve design problems?

One way of thinking about research and development is to recognise that firms are trying to solve particular design problems. We often build these design problems into our models, but are forced to oversimplify them in order to make the models solvable. The approach taken in this paper is to acknowledge that design problems are often insoluble using standard techniques and to model instead the process by which firms solve them. Two such processes are simulated in detail. The first, individual experimental search, is based on a problem-solving technique known as simulated annealing. The second, partial imitation, involves learning at a social level and is based on a problem-solving technique known as the genetic algorithm. Some economic implications of these processes are explored, including their application to stochastic learning curves, patent design and the importance of `technodiversity' in the introduction of new technology to developing countries.     

网络功能虚拟化中的性能感知服务组合优化

服务功能链是网络功能虚拟化的重要支撑,为了构建满足功能和性能需求的服务功能链,需要建立服务的性能模型,从而产生基于性能的服务组合优化问题。一种基于性能模型的服务组合优化问题被建模,并针对复杂约束情况下的无效解干扰,提出了改进的模拟退火算法,该算法包含基于层次属性的产生函数和基于偏离度的目标函数。仿真结果表明,该算法提高了21%的服务组合成功率,同时降低了组合成本和时间消耗。仿真结果验证了所提算法的有效性。     

基于区间PCA方法的中小上市公司综合评价

以深交所中小板最早上市的20家公司2004至2009年的年报数据为分析对象,可以提出一种易于实现、信息利用充分的区间主成分分析法,实现对样本公司的动态、长期综合评估.研究结果表明,综合排名靠前的上市公司大都属于高新技术企业且为细分行业龙头,排名靠后的大都属于传统制造业且科技含量不高.为促进中小板和创业板市场稳定发展,应...     

基于模拟退火遗传混合算法的指派问题研究

根据指派问题的特点建立数学模型．提出了以模拟退火算法和遗传算法相结合的思想及其解决方案。通过算例表明,使用此算法解决指派问题,提高了搜索效率,能够在短时间内找到最优分配方案,证明该算法是可行的。     

基于二层规划的选址库存路径问题研究

针对一个生产基地,多个配送中心和多个零售商的供应链二级分销网络,根据物流配送决策的实际过程,利用二层规划方法建立了一个选址库存路径问题模型,其中上层规划为配送中心选址模型,下层规划表示客户选择最佳配送中心、库存及路径问题,设计了双层模拟退火算法求解该模型,最后利用不同问题规模的算例将该算法与标准的模拟退火算法进行对比,结果证实改进算法的有效性。