Recently the phenomenon of disposable schoolbook in China not only has wasted so many resources that produce unfavorable influence, but also has increased unneeessary impact burdens on consumptions of Chinese families...Recently the phenomenon of disposable schoolbook in China not only has wasted so many resources that produce unfavorable influence, but also has increased unneeessary impact burdens on consumptions of Chinese families. The paper analyzes value of the reuse of schoolbooks and main obstacles, introduces the concept of servicizing, discusses the problem of the reuse of schoolbooks from construction of product-service system, and puts forward that realization of the reuse of sChoolbooks depends on innovation of present system and model. Construction of Schoolbook-service system needs shifl from value to consumption habits and behaviors and active participation of every Social class.展开更多
To assist conservationists and policymakers in managing and protecting forests in Beijing from the effects of climate change,this study predicts changes for 2012–2112 in habitable areas of three tree species—Betula ...To assist conservationists and policymakers in managing and protecting forests in Beijing from the effects of climate change,this study predicts changes for 2012–2112 in habitable areas of three tree species—Betula platyphylla,Quercus palustris,Platycladus orientalis,plus other mixed broadleaf species—in Beijing using a classification and regression tree niche model under the International Panel on Climate Change’s A2 and B2 emissions scenarios(SRES).The results show that climate change will increase annual average temperatures in the Beijing area by 2.0–4.7℃,and annual precipitation by 4.7–8.5 mm,depending on the emissions scenario used.These changes result in shifts in the range of each of the species.New suitable areas for distributions of B.platyphylla and Q.palustris will decrease in the future.The model points to significant shifts in the distributions of these species,withdrawing from their current ranges and pushing southward towards central Beijing.Most of the ranges decline during the initial 2012–2040 period before shifting southward and ending up larger overall at the end of the 88-year period.The mixed broadleaf forests expand their ranges significantly.The P.orientalis forests,on the other hand,expand their range marginally.The results indicate that climate change and its effects will accelerate significantly in Beijing over the next 88 years.Water stress is likely to be a major limiting factor on the distribution of forests and the most important factor affecting migration of species into and out of existing nature reserves.There is a potential for the extinction of some species.Therefore,long-term vegetation monitoring and warning systems will be needed to protect local species from habitat loss and genetic swamping of native species by hybrids.展开更多
Over the years much has been written about the industry life cycle and corporate life cycle, yet there has been remarkably little attention given to the relation between them and M&A, or why this relationship exists....Over the years much has been written about the industry life cycle and corporate life cycle, yet there has been remarkably little attention given to the relation between them and M&A, or why this relationship exists. Based on reviewing the industry life cycle and the corporate life cycle, we find the relationship between M&A and these life cycles, and then propose the life cycle of M&A. At last, we use the M&A life cycle to explain the characters of the merger waves over last 100 years.展开更多
By far, the researches on how to distribute blood products among different departments in hospital have not been further studied, though the problem of blood shortage and wastage that caused by improper blood allocati...By far, the researches on how to distribute blood products among different departments in hospital have not been further studied, though the problem of blood shortage and wastage that caused by improper blood allocation is severe, which may endanger patient's lives and impose considerable costs on hospitals. In order to solve this problem, this paper mainly studies on how to distribute the blood items among different departments within a hospital and investigates the allocation approach with the novel management method by centralizing the inventory of several different departments. By integrating the blood inventory requirements of some departments, the hospital could reduce the rate of blood shortage and wastage effectively, release the pressure of the occupancy of resources and reduce the bullwhip effect of blood products. This paper illustrates the centralization principle in hospital and formulates the mixed integer programming model to work out the optimal allocation network scheme and the optimal inventory setting for every department. And the results of the numerical example demonstrate that this centralization method could considerably reduce blood shortage and wastage in hospital by about 72% and 90% respectively. Furthermore, it could decrease the total cost by about 108,540 RMB a month on blood supply chain management in the hospital and improve the effect of some certain surgeries by transfusing the fresh blood to patients.展开更多
This paper gives a new method into the evaluating system of teleeom investment projects, i.e. Real Option. This may overcome the defects resulted from employing Net Present Value (NPV), which is nova used in the eva...This paper gives a new method into the evaluating system of teleeom investment projects, i.e. Real Option. This may overcome the defects resulted from employing Net Present Value (NPV), which is nova used in the evaluation of telecom projects. A theoretical analysis of Real Option is provided, followed by an example of telecom investment project to illustrate the differences between the two methods.展开更多
A semi-Markov model is proposed for congestion in weaving section at right exit with two lanes due to the method of cells modeling. The relationship among the arriving rate, turning-right rate, giving-way rate and the...A semi-Markov model is proposed for congestion in weaving section at right exit with two lanes due to the method of cells modeling. The relationship among the arriving rate, turning-right rate, giving-way rate and the congestion states is hence formulated by using the generating function. The results are illustrated that the weak interruption on traffic flow may leads to heavy congestion in road network although the capacity of main way and exit is definitely greater than the traffic flow.展开更多
The market share between China Mobile and China Unicom has stabilized since 2002. It is found that China Mobile has the superiority in the competition, for example, the scissors movement between its revenue and cost i...The market share between China Mobile and China Unicom has stabilized since 2002. It is found that China Mobile has the superiority in the competition, for example, the scissors movement between its revenue and cost indicates that it has a strong profit generating ability and there is enough room for it to reduce the price. The ratio between its price (marginal income) and marginal cost indicates that there is a very distant limit for it to reduce the price. Its demand is obviously flexible with the price, but it does not use the price weapon abundantly. The reason for the stabilization of the market is that China Mobile withdrew from the competition.展开更多
The stochastic resource allocation(SRA) problem is an extensive class of combinatorial optimization problems widely existing in complex systems such as communication networks and unmanned systems. In SRA, the ability ...The stochastic resource allocation(SRA) problem is an extensive class of combinatorial optimization problems widely existing in complex systems such as communication networks and unmanned systems. In SRA, the ability of a resource to complete a task is described by certain probability,and the objective is to maximize the reward by appropriately assigning available resources to different tasks. This paper is aimed at an important branch of SRA, that is, stochastic SRA(SSRA) for which the probability for resources to complete tasks is also uncertain. Firstly, a general SSRA model with multiple independent uncertain parameters(GSSRA-MIUP) is built to formulate the problem. Then,a scenario-based reformulation which can address multi-source uncertainties is proposed to facilitate the problem-solving process. Secondly, in view of the superiority of the differential evolution algorithm in real-valued optimization, a discrete version of this algorithm was originally proposed and further combined with a specialized local search to create an efficient hybrid optimizer. The hybrid algorithm is compared with the discrete differential evolution algorithm, a pure random sampling method, as well as a restart local search method. Experimental results show that the proposed hybrid optimizer has obvious advantages in solving GSSRA-MIUP problems.展开更多
文摘Recently the phenomenon of disposable schoolbook in China not only has wasted so many resources that produce unfavorable influence, but also has increased unneeessary impact burdens on consumptions of Chinese families. The paper analyzes value of the reuse of schoolbooks and main obstacles, introduces the concept of servicizing, discusses the problem of the reuse of schoolbooks from construction of product-service system, and puts forward that realization of the reuse of sChoolbooks depends on innovation of present system and model. Construction of Schoolbook-service system needs shifl from value to consumption habits and behaviors and active participation of every Social class.
基金This research was supported by the Fundamental Research Funds for the Central University(2018RD001).
文摘To assist conservationists and policymakers in managing and protecting forests in Beijing from the effects of climate change,this study predicts changes for 2012–2112 in habitable areas of three tree species—Betula platyphylla,Quercus palustris,Platycladus orientalis,plus other mixed broadleaf species—in Beijing using a classification and regression tree niche model under the International Panel on Climate Change’s A2 and B2 emissions scenarios(SRES).The results show that climate change will increase annual average temperatures in the Beijing area by 2.0–4.7℃,and annual precipitation by 4.7–8.5 mm,depending on the emissions scenario used.These changes result in shifts in the range of each of the species.New suitable areas for distributions of B.platyphylla and Q.palustris will decrease in the future.The model points to significant shifts in the distributions of these species,withdrawing from their current ranges and pushing southward towards central Beijing.Most of the ranges decline during the initial 2012–2040 period before shifting southward and ending up larger overall at the end of the 88-year period.The mixed broadleaf forests expand their ranges significantly.The P.orientalis forests,on the other hand,expand their range marginally.The results indicate that climate change and its effects will accelerate significantly in Beijing over the next 88 years.Water stress is likely to be a major limiting factor on the distribution of forests and the most important factor affecting migration of species into and out of existing nature reserves.There is a potential for the extinction of some species.Therefore,long-term vegetation monitoring and warning systems will be needed to protect local species from habitat loss and genetic swamping of native species by hybrids.
文摘Over the years much has been written about the industry life cycle and corporate life cycle, yet there has been remarkably little attention given to the relation between them and M&A, or why this relationship exists. Based on reviewing the industry life cycle and the corporate life cycle, we find the relationship between M&A and these life cycles, and then propose the life cycle of M&A. At last, we use the M&A life cycle to explain the characters of the merger waves over last 100 years.
文摘By far, the researches on how to distribute blood products among different departments in hospital have not been further studied, though the problem of blood shortage and wastage that caused by improper blood allocation is severe, which may endanger patient's lives and impose considerable costs on hospitals. In order to solve this problem, this paper mainly studies on how to distribute the blood items among different departments within a hospital and investigates the allocation approach with the novel management method by centralizing the inventory of several different departments. By integrating the blood inventory requirements of some departments, the hospital could reduce the rate of blood shortage and wastage effectively, release the pressure of the occupancy of resources and reduce the bullwhip effect of blood products. This paper illustrates the centralization principle in hospital and formulates the mixed integer programming model to work out the optimal allocation network scheme and the optimal inventory setting for every department. And the results of the numerical example demonstrate that this centralization method could considerably reduce blood shortage and wastage in hospital by about 72% and 90% respectively. Furthermore, it could decrease the total cost by about 108,540 RMB a month on blood supply chain management in the hospital and improve the effect of some certain surgeries by transfusing the fresh blood to patients.
基金This workis supported by Ministry of Education P.R.C(03036)Key Laboratory of Information Management and Information Economics, Min-istry of Education P.R.C(F04-22) .
文摘This paper gives a new method into the evaluating system of teleeom investment projects, i.e. Real Option. This may overcome the defects resulted from employing Net Present Value (NPV), which is nova used in the evaluation of telecom projects. A theoretical analysis of Real Option is provided, followed by an example of telecom investment project to illustrate the differences between the two methods.
基金This project is Supported by National Natural Science Foundation of China(70131160744, 70521001 and NCET-04-0173)
文摘A semi-Markov model is proposed for congestion in weaving section at right exit with two lanes due to the method of cells modeling. The relationship among the arriving rate, turning-right rate, giving-way rate and the congestion states is hence formulated by using the generating function. The results are illustrated that the weak interruption on traffic flow may leads to heavy congestion in road network although the capacity of main way and exit is definitely greater than the traffic flow.
文摘The market share between China Mobile and China Unicom has stabilized since 2002. It is found that China Mobile has the superiority in the competition, for example, the scissors movement between its revenue and cost indicates that it has a strong profit generating ability and there is enough room for it to reduce the price. The ratio between its price (marginal income) and marginal cost indicates that there is a very distant limit for it to reduce the price. Its demand is obviously flexible with the price, but it does not use the price weapon abundantly. The reason for the stabilization of the market is that China Mobile withdrew from the competition.
基金supported by the National Natural Science Foundation of China under Grant No.71361130011
文摘The stochastic resource allocation(SRA) problem is an extensive class of combinatorial optimization problems widely existing in complex systems such as communication networks and unmanned systems. In SRA, the ability of a resource to complete a task is described by certain probability,and the objective is to maximize the reward by appropriately assigning available resources to different tasks. This paper is aimed at an important branch of SRA, that is, stochastic SRA(SSRA) for which the probability for resources to complete tasks is also uncertain. Firstly, a general SSRA model with multiple independent uncertain parameters(GSSRA-MIUP) is built to formulate the problem. Then,a scenario-based reformulation which can address multi-source uncertainties is proposed to facilitate the problem-solving process. Secondly, in view of the superiority of the differential evolution algorithm in real-valued optimization, a discrete version of this algorithm was originally proposed and further combined with a specialized local search to create an efficient hybrid optimizer. The hybrid algorithm is compared with the discrete differential evolution algorithm, a pure random sampling method, as well as a restart local search method. Experimental results show that the proposed hybrid optimizer has obvious advantages in solving GSSRA-MIUP problems.