To improve the inventory control strategy for enterprise and optimize inventory control parameters of existing external and interior reverse logistics, a multi-resource inventory control model is proposed to better si...To improve the inventory control strategy for enterprise and optimize inventory control parameters of existing external and interior reverse logistics, a multi-resource inventory control model is proposed to better simulate the logistics fact, which is aimed at periodic inventory checking and pull mode of inventory control strategy, based on the return product arrival time obeying Poisson distribution, the return product employing lotsize process and the nonzero lead time of manufaeturinge/remanufacturing. The rational cost function with multiple constraints is employed to describe the inventory model. The genetic algorithm is employed to solve the inventory cost function to obtain the optimal solution of inventory checking periods, safe inventory point, product lot-sizes and process lot-sizes of return product. An example is presented to prove the feasibility and validity of the proposed method. Moreover, the influence of manufacturing/remanufacturing lead time and reuse rate of return production on the inventory control strategy of enterprise is analyzed.展开更多
Selection of crusher required a great deal of design based on the mining plan and operation input. Selection of the best primary crusher from all of available primary crushers is a Multi-Criterion Decision Making （M...Selection of crusher required a great deal of design based on the mining plan and operation input. Selection of the best primary crusher from all of available primary crushers is a Multi-Criterion Decision Making （MCDM） problem, in this paper, the Analytical Hierarchy Process （AHP） method was used to selection of the best primary crusher for Golegohar Iron Mine in Iran. For this reason, gyratory, double toggle jaw, single toggle jaw, high speed roll crusher, low speed sizer, impactor, hammer mill and feeder breaker crushers were considered as alternatives and capacity, feed size, product size, rock compressive strength, abrasion index and mobility of crusher were considered as criteria. As a result of our study, the gyvratory crusher was offered as the best primary crusher for the studied mine.展开更多
The article discusses plot size standards applied in the government sites-and-services projects in Khartoum and probes into the possible alternative ways of re-establishing solid grounds for those standards. The parti...The article discusses plot size standards applied in the government sites-and-services projects in Khartoum and probes into the possible alternative ways of re-establishing solid grounds for those standards. The particular issue of plot size is a crucial factor in the whole housing policy as it directly affects the urban land use and consumption and extends its influence far into sustainability and affordability issues and the whole housing policy and supply process. The article, analysing the applied standards, argues that plot subdivision can substantially contribute to providing more access of housing to the low-income groups. Large plot sizes can be subdivided driven by the need to realize security of tenure, doubling the owner-occupier housing stock which is the base issue of self-help housing, increases housing finance, provides variety of housing choices and behind all it conforms to the legacy principles and some cultural attributes of the local community. The article underlined existence of a cumbersome regulatory system, subdivision procedures and development controls which need to be reformed.展开更多
Age and body size are two important demographic traits that determine the life history strategies of populations and species. We measured these two parameters ofRana amurensis, at a 900 m and a 500 m altitude site in ...Age and body size are two important demographic traits that determine the life history strategies of populations and species. We measured these two parameters ofRana amurensis, at a 900 m and a 500 m altitude site in northeastern China. At the two sites, age at first reproduction was 2 years for males and 3 years for females. The maximum age of males and females at the high-altitude site was 6 and 7 years, and 5 and 7 years at the low-altitude population, respectively. Females were significantly larger than males in both populations, due to greater age in both the high- and low-altitude sites, Body size of either males or fe- males did not differ significantly between populations; only males showed increased body size at the high-altitude site when age effect was statistically controlled for. The increased cline of male body size may be attributable to delayed maturation of the sex due to a shorter growing season at high altitudes展开更多
基金Sponsored by the National High Technology Research and Development Program of China(Grant No.2003AA413210)
文摘To improve the inventory control strategy for enterprise and optimize inventory control parameters of existing external and interior reverse logistics, a multi-resource inventory control model is proposed to better simulate the logistics fact, which is aimed at periodic inventory checking and pull mode of inventory control strategy, based on the return product arrival time obeying Poisson distribution, the return product employing lotsize process and the nonzero lead time of manufaeturinge/remanufacturing. The rational cost function with multiple constraints is employed to describe the inventory model. The genetic algorithm is employed to solve the inventory cost function to obtain the optimal solution of inventory checking periods, safe inventory point, product lot-sizes and process lot-sizes of return product. An example is presented to prove the feasibility and validity of the proposed method. Moreover, the influence of manufacturing/remanufacturing lead time and reuse rate of return production on the inventory control strategy of enterprise is analyzed.
文摘Selection of crusher required a great deal of design based on the mining plan and operation input. Selection of the best primary crusher from all of available primary crushers is a Multi-Criterion Decision Making （MCDM） problem, in this paper, the Analytical Hierarchy Process （AHP） method was used to selection of the best primary crusher for Golegohar Iron Mine in Iran. For this reason, gyratory, double toggle jaw, single toggle jaw, high speed roll crusher, low speed sizer, impactor, hammer mill and feeder breaker crushers were considered as alternatives and capacity, feed size, product size, rock compressive strength, abrasion index and mobility of crusher were considered as criteria. As a result of our study, the gyvratory crusher was offered as the best primary crusher for the studied mine.
文摘The article discusses plot size standards applied in the government sites-and-services projects in Khartoum and probes into the possible alternative ways of re-establishing solid grounds for those standards. The particular issue of plot size is a crucial factor in the whole housing policy as it directly affects the urban land use and consumption and extends its influence far into sustainability and affordability issues and the whole housing policy and supply process. The article, analysing the applied standards, argues that plot subdivision can substantially contribute to providing more access of housing to the low-income groups. Large plot sizes can be subdivided driven by the need to realize security of tenure, doubling the owner-occupier housing stock which is the base issue of self-help housing, increases housing finance, provides variety of housing choices and behind all it conforms to the legacy principles and some cultural attributes of the local community. The article underlined existence of a cumbersome regulatory system, subdivision procedures and development controls which need to be reformed.
文摘Age and body size are two important demographic traits that determine the life history strategies of populations and species. We measured these two parameters ofRana amurensis, at a 900 m and a 500 m altitude site in northeastern China. At the two sites, age at first reproduction was 2 years for males and 3 years for females. The maximum age of males and females at the high-altitude site was 6 and 7 years, and 5 and 7 years at the low-altitude population, respectively. Females were significantly larger than males in both populations, due to greater age in both the high- and low-altitude sites, Body size of either males or fe- males did not differ significantly between populations; only males showed increased body size at the high-altitude site when age effect was statistically controlled for. The increased cline of male body size may be attributable to delayed maturation of the sex due to a shorter growing season at high altitudes
