The two-echelon inventory system considered in this work is based on one single supplier, multiple distribution centers, and multiple retailers. In each echelon safety inventory is centralized stored in several centra...The two-echelon inventory system considered in this work is based on one single supplier, multiple distribution centers, and multiple retailers. In each echelon safety inventory is centralized stored in several centralized storage centers and lateral transshipment of safety stock is permitted between centralized storage site and non-centralized storage sites. The inventory positioning and location decision model developed focuses on safety stock cost, lateral transshipment cost, transportation cost, construction cost and shortage cost in multi-echelon supply chain. Numerical experiments show that: no matter whether in the echelon of distribution centers or retailers the factors which affect the selection from one single centralized storage center or multiple centralized storage centers are distance between distribution centers or retailers, unit transshipment cost and unit inventory carrying cost.展开更多
This paper presented a preliminary research on the central solar heating system with seasonal storage(CSHSSS)used in cold climate in China.A mathematical model of the solar energy seasonal storage water tank used in t...This paper presented a preliminary research on the central solar heating system with seasonal storage(CSHSSS)used in cold climate in China.A mathematical model of the solar energy seasonal storage water tank used in the central solar heating system was firstly developed based on energy conservation.This was followed by the simulation of the CSHSSS used in a two-floor villa in Harbin,and analysis of the impacts on storage water temperature of tank volume,solar collector area,tank burial depth,insulation thickness around the tank,etc.The results show there is a relatively economical tank volume to optimize the system efficiency,which decreases with increasing tank volume at the constant collector area,and increases with increasing collector area at the constant tank volume.Furthermore,the insulation thickness has obvious effect on avoiding heat loss,while the tank burial depth doesn't.In addition,the relationship between the solar collector efficiency and storage water temperature is also obtained,it decreases quickly with increasing storing water temperature,and then increases slowly after starting space heating system.These may be helpful for relevant design and optimization in cold climates in China and all over the world.展开更多
USA nuclear waste management program has stalled due to its continued insistence upon using Yucca Mountain for its disposal of DOE （Department of Energy） and commercial power plants NSF （nuclear spent fuel）. Incre...USA nuclear waste management program has stalled due to its continued insistence upon using Yucca Mountain for its disposal of DOE （Department of Energy） and commercial power plants NSF （nuclear spent fuel）. Increased flexibility and significant changes in DOE program are proposed. They include a private waste company to manage it; the construction and operation of ICS （interim centralized storage） facilities for NSF; the search for an AGR （alternate geological repository）; the use of a different methodology involving key local and state participants; a new ＂as safe as practical＂ strategy with defined benefits to the involved locations and states. Assured removal of NSF from ICS and providing limited Price Anderson indemnity for the program will enhance its acceptance. Minimum politics, regular information meetings, compromises, good cost projections and meeting schedules will be necessary to increase the chances of the proposed nuclear waste management program.展开更多
基金supported by the Philosophy and Social Science Program of Guangdong Province(Grant No.GD16XGL15)the Key Scientific Research Projects of the Education Department of Guangdong Province(Grant No.2017GWTSCX032)
文摘The two-echelon inventory system considered in this work is based on one single supplier, multiple distribution centers, and multiple retailers. In each echelon safety inventory is centralized stored in several centralized storage centers and lateral transshipment of safety stock is permitted between centralized storage site and non-centralized storage sites. The inventory positioning and location decision model developed focuses on safety stock cost, lateral transshipment cost, transportation cost, construction cost and shortage cost in multi-echelon supply chain. Numerical experiments show that: no matter whether in the echelon of distribution centers or retailers the factors which affect the selection from one single centralized storage center or multiple centralized storage centers are distance between distribution centers or retailers, unit transshipment cost and unit inventory carrying cost.
基金Supported by Multi-Discipline Scientific Rearch Foundation of Harbin Institute of Technology(HIT MD2003.1)Postdoctoral Scientific Rearch Foundation of Heilongjiang Provine(LBH-Q06066)
文摘This paper presented a preliminary research on the central solar heating system with seasonal storage(CSHSSS)used in cold climate in China.A mathematical model of the solar energy seasonal storage water tank used in the central solar heating system was firstly developed based on energy conservation.This was followed by the simulation of the CSHSSS used in a two-floor villa in Harbin,and analysis of the impacts on storage water temperature of tank volume,solar collector area,tank burial depth,insulation thickness around the tank,etc.The results show there is a relatively economical tank volume to optimize the system efficiency,which decreases with increasing tank volume at the constant collector area,and increases with increasing collector area at the constant tank volume.Furthermore,the insulation thickness has obvious effect on avoiding heat loss,while the tank burial depth doesn't.In addition,the relationship between the solar collector efficiency and storage water temperature is also obtained,it decreases quickly with increasing storing water temperature,and then increases slowly after starting space heating system.These may be helpful for relevant design and optimization in cold climates in China and all over the world.
文摘USA nuclear waste management program has stalled due to its continued insistence upon using Yucca Mountain for its disposal of DOE （Department of Energy） and commercial power plants NSF （nuclear spent fuel）. Increased flexibility and significant changes in DOE program are proposed. They include a private waste company to manage it; the construction and operation of ICS （interim centralized storage） facilities for NSF; the search for an AGR （alternate geological repository）; the use of a different methodology involving key local and state participants; a new ＂as safe as practical＂ strategy with defined benefits to the involved locations and states. Assured removal of NSF from ICS and providing limited Price Anderson indemnity for the program will enhance its acceptance. Minimum politics, regular information meetings, compromises, good cost projections and meeting schedules will be necessary to increase the chances of the proposed nuclear waste management program.
