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931.
本文从复变函数展开为幂级数的待定系数法出发,提出了幂级数的除法的概念,并给出了幂级数的除法的运作方式,从而有效地解决了待定系数法比较繁杂这一困难,同时保证了运算结果的准确性。  相似文献   
932.
为满足转向架检修的需求,在转向架检修库中特别设置一个立体存放库。由于国内目前没有转向架的立体存放库,故采用升降横移式立体车库的方式对转向架存放库货架结构进行了设计。通过有限元方法对货架进行分析与计算,在保证货架承载强度、变形和稳定性的要求下,将原来的壁厚8 mm的钢板改为6 mm,从而减轻了货架的质量,满足了仓储的需要。  相似文献   
933.
This paper develops a mathematical model for the optimal stopping design of limited-stop bus service, which allows each bus vehicle to skip some stops. To better reflect the reality, this paper considers the vehicle capacity and stochastic travel time. Also, vehicles are all allowed to skip stops whereas any stop is not allowed to be skipped by two consecutive vehicles. A hybrid artificial bee colony (ABC) and Monte Carlo method is developed to solve the optimal stopping strategy. Finally, the model and solution method are validated by a numerical example, and a sensitivity analysis is performed on the passenger demand.  相似文献   
934.
Details about the movement of trucks on postal express lines are investigated to improve the performances of mail distribution. A mixed driving pattern of trucks is introduced to minimize the transportation cost of a postal express line network with a service level requirement. We formulate this problem as a mixed p meeting depots location with shipment scheduling problem and build a MINLP model. A two-level tabu search procedure based on shipment grouping method is developed. Through a series of computational experiments and sensitivity analysis on different instances, some managerial insights of the network under mixed driving pattern are revealed.  相似文献   
935.
Lagrange-Galerkin方法是求解传导占优的扩散问题的数值方法.它将Galerkin 有限元法和沿着质点轨道上关于物质导数的特殊离散结合在一起. 本文作者研究了非定常热对流传导问题的Lagrange-Galerkin 方法的存在性和最优误差估计.  相似文献   
936.
In this paper, we propose a method for improving the accuracy of the estimation of interregional input–output tables, by combining the RAS method and the real-coded Genetic Algorithm (GA); these are simple representative methods for the estimation of an interregional input–output table. By comparing the performance evaluation results obtained using the proposed method, the RAS method, and Simulated Annealing, we verified that the combination of the genetic algorithm and the RAS method can enhance the estimation accuracy of an interregional input–output table. In addition, performance is further enhanced by adjusting GA parameters.  相似文献   
937.
This paper aims to measure the perceived container leasing prices at different ports by presenting a two-stage optimization method. In stage I, we propose a practical liner shipping network design problem with empty container repositioning. The proposed problem further considers the use of foldable containers and allows the mutual substitution between empty containers to decrease the number of empty containers to be repositioned. In stage II, the inverse optimization technique is used to determine the perceived container leasing prices at different ports, based on the solution obtained in stage I. Based on a set of candidate liner shipping service routes, a mixed-integer nonlinear programming model is built for the proposed problem in stage I. The nonlinear terms are linearized by introducing the auxiliary variables. Numerical experiments based on a realistic Asia-Europe-Oceania liner shipping network are carried out to account for the effectiveness of our two-stage optimization method.  相似文献   
938.
Industrial heritage tourism has become increasingly popular in recent years. However, strategies for improving the industrial heritage tourism development-related performances are still an underdeveloped research topic academically. Therefore, this study’s purpose is to explore the feasibility performance-improving strategies using a hybrid-modified multiple attribute decision-making (MADM) based on the DEMATEL technique in constructing the influential network relation map (INRM) and in determining the influential weights of DANP. Then, the modified VIKOR method is combined with the influential weights of DANP, performance gaps were identified, and then the most effective strategies for improving tourism development-related performance at industrial heritage sites can be generated using INRM. Finally, an empirical real case study of a rehabilitated gold-mining site of Taiwan is used to demonstrate the effectiveness of the hybrid-modified MADM model. According to the results, the decision-makers should highly prioritize improving high-priority criteria such as ‘social usefulness’, ‘resource integration’, ‘destination policy and development’, ‘economic development’, ‘cultural links’, ‘cultural learning’, and ‘natural landscape resources’ in advance to successfully achieving the aspired performance levels. Additionally, this study suggests meaningful industrial heritage tourism performance improvement strategies that have been rehabilitated throughout the world.  相似文献   
939.
铁路枢纽物流中心站是枢纽内组织各种物流运转、完成物流功能、提供物流服务的重要节点.分析铁路枢纽物流中心站选址影响因素,引入集对-熵权理论分析模型,提出在合肥北站建立物流中心站和在钟油坊站建立辅助中心站的选址方案建议.  相似文献   
940.
帽梁施工采用无支架法施工相对满堂支架法施工而言,具有施工简便,对地面承载力无要求,节约大量钢管,降低施工成本,缩短工期等优点。文章针对洛湛铁路旺甫1号三线大桥设计出穿心棒无支架法施工帽梁的支撑系统方案,成功地解决了三线大桥因帽梁砼重量大、跨度长而致使常用材料不适合做承托梁的问题,并对支撑系统进行了受力检算。  相似文献   
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