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双星形结构和完备结构快件网的成本模型
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作者 许顺斗 宋学君 涂奉生 《邮政研究》 1998年第4期36-38,44,共4页
在邮区中心局体制的框架下,以连续空间近似方法为工具,建立了双星形结构快件网和完备结构快件网的系统成本模型,讨论了各项成本之间的相互影响和协调性,建立的模型可用于我国邮政快件网的分析与设计,在规划建设快件网时使用。
关键词 邮区 中心局 快件网 连续空间近似 系统成本模型
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放射式轨道路网的系统出行成本研究 被引量:1
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作者 许贺 李文权 +1 位作者 丁钰玲 林叶倩 《武汉理工大学学报(交通科学与工程版)》 2014年第1期167-171,共5页
探讨放射式轨道路网下的系统出行成本,能够为评价轨道交通服务水平、确定合理的线路数量和运营参数提供理论支持.基于研究区域人口密度服从Clark分布,建立了系统出行成本模型.模型将乘客在步行时间、车站等待时间和车上等待时间换算为... 探讨放射式轨道路网下的系统出行成本,能够为评价轨道交通服务水平、确定合理的线路数量和运营参数提供理论支持.基于研究区域人口密度服从Clark分布,建立了系统出行成本模型.模型将乘客在步行时间、车站等待时间和车上等待时间换算为费用作为系统出行成本的一部分,结合运营商的运营和维护成本得到系统人均出行总成本.以成都市为例,通过模型分析确定最优发车频率为13veh/h、轨道线路数为5条,较符合实际情况,验证了模型的有效性. 展开更多
关键词 轨道交通 系统出行成本模型 拥挤惩罚系数 参数标定
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Combination of Ecoprofile and Least-cost Model for Eco-network Planning 被引量:3
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作者 XIAO He LIU Yunhui +2 位作者 YU Zhenrong ZHANG Qian ZHANG Xin 《Chinese Geographical Science》 SCIE CSCD 2014年第1期113-125,共13页
The protecting requirements and functional connectivity of species in isolated habitat patches are crucial factors of eco-network planning.This study aimed to improve the method of eco-network planning for species con... The protecting requirements and functional connectivity of species in isolated habitat patches are crucial factors of eco-network planning.This study aimed to improve the method of eco-network planning for species conservation.Ecoprofiling was used to group the species by similar behavior types,namely,choice of ecosystem,area requirement,and short distance dispersal abilities.A least-cost model was used to simulate the optimal corridor location to maintain functional connectivity.A combination of ecoprofile and least-cost model was hired to develop an eco-network that promoted species conservation.A case study was also conducted in Beijing,China.In addition to the required ecosystem,habitat area is an important parameter for habitat extraction.Habitat area can remove noise habitat patches because of lacking area.Short-distance dispersal can be used to identify corridor requirements and avoid unnecessary building requirements.Species with various dispersal abilities exhibit significant differences in terms of corridor length and location requirement.Habitat isolation is the main threat for weakly mobile species,and habitat loss is the major risk of mobile species protection.Different species groups also exhibit distinct landscape pattern demands for an eco-network,and the eco-network planning based on specific species can not protect other species.We proposed that a combination of ecoprofile and least-cost model improved the efficiency of species conservation by eco-network planning. 展开更多
关键词 eco-network ecoprofile least-cost model biodiversity conservation BEIJING China
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Maintenance decision-making method for manufacturing system based on cost and arithmetic reduction of intensity model 被引量:4
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作者 刘繁茂 朱海平 刘伯兴 《Journal of Central South University》 SCIE EI CAS 2013年第6期1559-1571,共13页
A cost-based selective maintenance decision-making method was presented.The purpose of this method was to find an optimal choice of maintenance actions to be performed on a selected group of machines for manufacturing... A cost-based selective maintenance decision-making method was presented.The purpose of this method was to find an optimal choice of maintenance actions to be performed on a selected group of machines for manufacturing systems.The arithmetic reduction of intensity model was introduced to describe the influence on machine failure intensity by different maintenance actions (preventive maintenance,minimal repair and overhaul).In the meantime,a resolution algorithm combining the greedy heuristic rules with genetic algorithm was provided.Finally,a case study of the maintenance decision-making problem of automobile workshop was given.Furthermore,the case study demonstrates the practicability of this method. 展开更多
关键词 selective maintenance preventive maintenance arithmetic reduction of intensity model hybrid genetic algorithm
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公交线网优化新技术的应用研究 被引量:2
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作者 张蕾 Paulo Sergio Custodio 《交通标准化》 2013年第21期15-20,共6页
针对现有公交线网优化研究模型求解复杂、可操作性不强的现状,提出了一种新的公交线网优化方法:从分析乘客对线网的需求意愿入手,获取线网优化要重点解决的问题,在此基础上提出优化策略,建立平衡乘客及公交运营企业利益的系统成本最优... 针对现有公交线网优化研究模型求解复杂、可操作性不强的现状,提出了一种新的公交线网优化方法:从分析乘客对线网的需求意愿入手,获取线网优化要重点解决的问题,在此基础上提出优化策略,建立平衡乘客及公交运营企业利益的系统成本最优模型。最后以济南为例,验证方法的可操作性和优化结果的可实施性。 展开更多
关键词 公交线网优化技术 优化策略 系统成本最优模型
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EQUILIBRIUM IN AN OVERLAPPING GENERATIONS MODEL WITH ALTRUISTIC PREFERENCE WHEN MARKETS ARE FRICTIONAL
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《Journal of Systems Science & Complexity》 SCIE EI CSCD 2002年第2期113-124,共12页
Abstract. This paper examines the equilibrium existence of an overlapping generationsmodel with transaction costs. Moreover, we also show that if the equilibrium prices ofbuying equal those of selling the equilibrium ... Abstract. This paper examines the equilibrium existence of an overlapping generationsmodel with transaction costs. Moreover, we also show that if the equilibrium prices ofbuying equal those of selling the equilibrium allocations are pareto effiCient when the valueof the aggregate endowment at equilibrium price is finite. 展开更多
关键词 OLG Model altruistic preference transaction costs pareto optimum.
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