Petrol is a kind of strategic natural resources. Provide legitimate transportation plans for the petrol secondary distribution are the key links to guarantee the petrol provision. If the total supply is insufficient, ...Petrol is a kind of strategic natural resources. Provide legitimate transportation plans for the petrol secondary distribution are the key links to guarantee the petrol provision. If the total supply is insufficient, some petrol stations can’t avoid shortage because their demands could not be met. So the shortage cost will appear. This paper studies the problem of how to arrange the transportation plan in order to minimize the total cost when the total volume of supply is insufficient. Given the storage volume, the sales rate and the unit shortage cost of every petrol station, considering the full loading constraints of the compartment vehicle, a mixed integer programming model for minimizing the total cost of petrol secondary distribution is established. A Lingo program is compiled for solving the model. Finally, simulation on an example has been done and a reasonable transportation plan is obtained. The model and algorithm in this paper can provide a theoretical basis for dispatching department to make transportation plan.展开更多
The goal of the research is to develop a methodology to minimize the public’s exposure to harmful emissions from coal power plants while maintaining minimal operational costs related to electric distribution losses a...The goal of the research is to develop a methodology to minimize the public’s exposure to harmful emissions from coal power plants while maintaining minimal operational costs related to electric distribution losses and coal logistics. The objective is achieved by combining EPA Screen3, ISC3 and Japanese METI-LIS model equations with minimum spanning tree (MST) algorithm. Prim’s MST algorithm is used to simulate an electric distribution system and coal transportation pathways. The model can detect emission interaction with another source and estimate the ground level concentrations of emissions up to distances of 25 kilometers. During a grid search, the algorithm helps determine a candidate location, for a new coal power plant, that would minimize the operational cost while ensuring emission exposure is below the EPA/NIOSH thresholds. The proposed methodology has been coded in form of a location analysis simulation. An exhaustive search strategy delivers a final candidate location for a new coal power plant to ensure minimum operational costs as compared to the random or greedy search strategy. The simulation provides a tool to industrial zone planners, environmental engineers, and stakeholders in coal-based power generation. Using operational and emissions perspectives, the tool helps ascertain a list of compromise locations for a new coal power plant facility.展开更多
为推动城市内Mobility as a Service系统构建,并解决其票务支付一体化和换乘服务的相关问题。文章首先从MaaS系统的特性出发,分析MaaS系统框架的构成及其关键因素;其次在考虑上述关键因素的基础上,以单一类型交通方式费用、换乘费用和...为推动城市内Mobility as a Service系统构建,并解决其票务支付一体化和换乘服务的相关问题。文章首先从MaaS系统的特性出发,分析MaaS系统框架的构成及其关键因素;其次在考虑上述关键因素的基础上,以单一类型交通方式费用、换乘费用和服务费用为核心,构建了基于MaaS系统的交通费用模型;然后考虑出行时间和舒适度,构建了面向MaaS系统的交通广义费用模型,以解决票务支付一体化和换乘费用等问题;最后以成都市为例,定量分析了模型内各项参数并使用不同模型计算出行费用、时间,以出行费用和广义费用作为评价依据,分析得出基于MaaS系统的交通费用模型所具有的优势。从而为整合交通资源、建立城市MaaS交通体系提供合理依据。展开更多
This paper suggests an extending conventional gravity model design to empirically analyze the effect of transport costs and port efficiency on China's export flows. It shows that factor endowment and transport cos...This paper suggests an extending conventional gravity model design to empirically analyze the effect of transport costs and port efficiency on China's export flows. It shows that factor endowment and transport costs variables affect export trade value in directions that New Trade Theory(NTT) predicted. Also, the evidence indicates that, controlling for the effects of transport costs on trade, variables in traditional gravity model are consistent with previous empirical studies in both magnitudes and directions. Moreover, more than 22% of the variation in Chinese export trade can be explained by those three variables alone. The findings reported in this paper empirically explains how seriously transport costs and port efficiency affect China's export growth by comparing effects of labour production factor costs on external trade. It suggests that the improvement of port efficiency and reduction of road transport costs play a vital role in China's export competitiveness in the global market.展开更多
文摘Petrol is a kind of strategic natural resources. Provide legitimate transportation plans for the petrol secondary distribution are the key links to guarantee the petrol provision. If the total supply is insufficient, some petrol stations can’t avoid shortage because their demands could not be met. So the shortage cost will appear. This paper studies the problem of how to arrange the transportation plan in order to minimize the total cost when the total volume of supply is insufficient. Given the storage volume, the sales rate and the unit shortage cost of every petrol station, considering the full loading constraints of the compartment vehicle, a mixed integer programming model for minimizing the total cost of petrol secondary distribution is established. A Lingo program is compiled for solving the model. Finally, simulation on an example has been done and a reasonable transportation plan is obtained. The model and algorithm in this paper can provide a theoretical basis for dispatching department to make transportation plan.
文摘The goal of the research is to develop a methodology to minimize the public’s exposure to harmful emissions from coal power plants while maintaining minimal operational costs related to electric distribution losses and coal logistics. The objective is achieved by combining EPA Screen3, ISC3 and Japanese METI-LIS model equations with minimum spanning tree (MST) algorithm. Prim’s MST algorithm is used to simulate an electric distribution system and coal transportation pathways. The model can detect emission interaction with another source and estimate the ground level concentrations of emissions up to distances of 25 kilometers. During a grid search, the algorithm helps determine a candidate location, for a new coal power plant, that would minimize the operational cost while ensuring emission exposure is below the EPA/NIOSH thresholds. The proposed methodology has been coded in form of a location analysis simulation. An exhaustive search strategy delivers a final candidate location for a new coal power plant to ensure minimum operational costs as compared to the random or greedy search strategy. The simulation provides a tool to industrial zone planners, environmental engineers, and stakeholders in coal-based power generation. Using operational and emissions perspectives, the tool helps ascertain a list of compromise locations for a new coal power plant facility.
文摘为推动城市内Mobility as a Service系统构建,并解决其票务支付一体化和换乘服务的相关问题。文章首先从MaaS系统的特性出发,分析MaaS系统框架的构成及其关键因素;其次在考虑上述关键因素的基础上,以单一类型交通方式费用、换乘费用和服务费用为核心,构建了基于MaaS系统的交通费用模型;然后考虑出行时间和舒适度,构建了面向MaaS系统的交通广义费用模型,以解决票务支付一体化和换乘费用等问题;最后以成都市为例,定量分析了模型内各项参数并使用不同模型计算出行费用、时间,以出行费用和广义费用作为评价依据,分析得出基于MaaS系统的交通费用模型所具有的优势。从而为整合交通资源、建立城市MaaS交通体系提供合理依据。
基金supported by the National Natural Science Foundation of China under Grant Nos.71390330,71390331,71390335,71373262,and 71373023Academic Human Resources Development in Beijing Union University under Grant No.Rk100201509
文摘This paper suggests an extending conventional gravity model design to empirically analyze the effect of transport costs and port efficiency on China's export flows. It shows that factor endowment and transport costs variables affect export trade value in directions that New Trade Theory(NTT) predicted. Also, the evidence indicates that, controlling for the effects of transport costs on trade, variables in traditional gravity model are consistent with previous empirical studies in both magnitudes and directions. Moreover, more than 22% of the variation in Chinese export trade can be explained by those three variables alone. The findings reported in this paper empirically explains how seriously transport costs and port efficiency affect China's export growth by comparing effects of labour production factor costs on external trade. It suggests that the improvement of port efficiency and reduction of road transport costs play a vital role in China's export competitiveness in the global market.
