Is Chinese urbanization going to take a long time, or can its development goal be achieved by the government in a short time? What is the highest stable urbanization level that China can reach? When can China complete...Is Chinese urbanization going to take a long time, or can its development goal be achieved by the government in a short time? What is the highest stable urbanization level that China can reach? When can China complete its urbanization? To answer these questions, this paper presents a system dynamic(SD) model of Chinese urbanization, and its validity and simulation are justified by a stock-flow test and a sensitivity analysis using real data from 1998 to 2013. Setting the initial conditions of the simulation by referring to the real data of 2013, the multi-scenario analysis from 2013 to 2050 reveals that Chinese urbanization will reach a level higher than 70% in 2035 and then proceed to a slow urbanization stage regardless of the population policy and GDP growth rate settings; in 2050, Chinese urbanization levels will reach approximately 75%, which is a stable and equilibrium level for China. Thus, it can be argued that Chinese urbanization is a long social development process that will require approximately20 years to complete and that the ultimate urbanization level will be 75–80%, which means that in the distant future, 20–25% of China's population will still settle in rural regions of China.展开更多
The economic growth of China has led to increasing growth disparities between regions. Such disparities are uncontrolled and are severely negative symptoms in the process of economic development. On the basis of syste...The economic growth of China has led to increasing growth disparities between regions. Such disparities are uncontrolled and are severely negative symptoms in the process of economic development. On the basis of system dynamics(SD) modeling and the relationship between industrial relocation and regional economic growth, we construct a model of the interrelationship between the two aforementioned phenomena. The model is an effective and creative exploration for examining effects of industrial relocation on Chinese regional economic growth disparities. The SD model is employed in this study to build an inter-regional labor migration SD model, an inter-regional capital migration SD model, an intra-industry SD model, an intra-regional population SD model, and an intra-regional SD model which are based on realities in labor and capital flow from the view of industrial relocation. VENSIM software is utilized to perform a system simulation based on the data of the eastern, middle, and western regions from 2000 to 2010. Results show that industrial relocation gradually narrows the relative disparity in GDP among the three regions. Moreover, the absolute one is enlarged continuously. The absolute and relative disparities in per capita GDP among eastern, middle, and western regions generally exhibit decreasing trends.展开更多
Since the implementation of the economic reform and opening up policy in 1978,China has miraculously created long-term high-speed economic growth,but has also had to face the problem of excessive consumption of resour...Since the implementation of the economic reform and opening up policy in 1978,China has miraculously created long-term high-speed economic growth,but has also had to face the problem of excessive consumption of resources as well as an intensification of environmental pollution.As a result,China is now facing a slowdown in development.China must maintain a certain speed of development to realize its goal of being a powerful nation,and becoming a developed country by 2050.To this end,China is facing a transformation of its economic development.There is a need to agree on an expected economic growth rate,along with the corresponding development modes or means of regulation in the medium-and long-term periods.This study developed a systematic-dynamic model to simulate the coupling relationship between economic growth,development modes,and the environmental supply system,and explored the possible options for future economic growth as well as the resource use and environmental protection requirements(the main factors).The results showed that to achieve the development goal of becoming a developed country by 2050,while maintaining a good ecological environment,the suitable growth rate for China's economy is 3.8%–6.3%.Within this range,a growth rate of 3.8%–4.4%was found to be relatively safe,while a growth rate of 4.4%–6.3%required further technical progress.This study provides an early warning in regard to China's environmental and development status.The study was a response to the"Future Earth"framework document and,in terms of development speed,it developed a theoretical system for the determination of resource and environmental carrying capacity(RECC).展开更多
Fully mechanized mining with large mining height(FMMLMH)is widely used in thick coal seam mining face for its higher recovery ratio,especially where the thickness is less than 7.0 m.However,because of the great mining...Fully mechanized mining with large mining height(FMMLMH)is widely used in thick coal seam mining face for its higher recovery ratio,especially where the thickness is less than 7.0 m.However,because of the great mining height and intense rock pressure,the coal wall rib spalling,roof falling and the instability of support occur more likely in FMMLMH working face,and the above three types of disasters interact with each other with complicated relationships.In order to get the relationship between each two of coal wall,roof,floor and support,and reduce the occurrence probability of the three types of disasters,we established the system dynamics(SD)model of the support-surrounding rock system which is composed of"coal wall-roof-floor-support"(CW-R-F-S)in a FMMLMH working face based on the condition of No.15104 working face in Sijiazhuang coal mine.With the software of Vensim,we also simulated the interaction process between each two factors of roof,floor,coal wall and the support.The results show that the SD model of"CW-R-F-S"system can reveal the complicated and interactive relationship clearly between the support and surrounding rock in the FMMLMH working face.By increasing the advancing speed of working face,the support resistance or the length of support guard,or by decreasing the tipto-face distance,the stability of"CW-R-F-S"system will be higher and the happening probability of the disasters such as coal wall rib spalling,roof falling or the instability of support will be lower.These research findings have been testified in field application in No.15104 working face,which can provide a new approach for researching the interaction relationship of support and surrounding rock.展开更多
System dynamics (SD) theory has long been deployed in modeling complex non-linear interrelationships but, so far it has not been common to do the kind of modeling in support of bringing environmental sustainability po...System dynamics (SD) theory has long been deployed in modeling complex non-linear interrelationships but, so far it has not been common to do the kind of modeling in support of bringing environmental sustainability policies to practice. This is largely because the challenge of including spatial data has not yet been well met. Potential for adoption of SD and GIS methods in combination is exemplified with the results of a decision-support exercise designed for simulation and prediction of the dynamic inter-relationships between socio-economic development and environmental quality for the "Wen, Pi, Du" county in Sichuan province, southwestern China.展开更多
Land use/cover change （LUCC） models are helpful tools for analyzing driving forces and processes of land use changes, assessing ecological impacts of land use change and decision-making for land use planning. Howeve...Land use/cover change （LUCC） models are helpful tools for analyzing driving forces and processes of land use changes, assessing ecological impacts of land use change and decision-making for land use planning. However, no single model is able to capture all the essential key processes to explore land use change at different spatial-temporal scales and make a full assessment of driving factors and macro-ecological impacts. Taken Ganzhou District as a case study, this paper describes an integrated analysis （IA） ap- proach by combining with system dynamics （SD） model, the Conversion of Land Use and its Effects at Small regional extent （CLUE-S） model and landscape indices method to analyze land use dynamics at different spatial-temporal scales. The SD model was used to calculate and predict demands for different land use types at the macro-scale as a whole during 2000-2035. The LUCC process was simulated at a high spatial resolution with the spatial consideration of land use spatial policies and restrictions to satisfy the balance between land use demand and supply by using the CLUE-S model, and Kappa values of the map simulation are 0.86 and 0.81 in 2000 and 2005, respectively. Finally, we evaluated the macro-ecological effect of LUCC and optimized sce- nario managements of land use by using landscape indices method. The IA approach could be used for better understanding the complexity of land use change and provide scientific support for land use planning and management, and the simulation results also could be used as a source data for scenario analysis of different hydrological and ecological processes based on different un- derlying surface of LUCC.展开更多
A series of advantages of single difference (SD) and undifferenced (ZD) models are given as compared with the double difference (DD) model. However, rank defects exist in SD and ZD models. The reparameterization metho...A series of advantages of single difference (SD) and undifferenced (ZD) models are given as compared with the double difference (DD) model. However, rank defects exist in SD and ZD models. The reparameterization method is provided to resolve this rank defect problem by estimating some combinations of the unknowns rather than the unknowns themselves. The reparameterization of SD and ZD functional models is discussed in detail with their stochastic models. The theoretical confirmation of the equivalence of undifferenced and differenced models is described in a straightforward way. The relationship between SD and ZD residuals is given and verified for some special purposes, e.g. research on the stochastical properties of GPS observations.展开更多
Based on the system dynamics(SD) model, this paper puts forward a quantitative method to evaluate the earthquake emergency plan in China. Firstly, we analyze the disaster system structure and the content of plan. Usin...Based on the system dynamics(SD) model, this paper puts forward a quantitative method to evaluate the earthquake emergency plan in China. Firstly, we analyze the disaster system structure and the content of plan. Using the analysis results, we establish a system dynamics(SD) model and then carry out its simulation. According to the simulation results, the rescue effect using the plan of 2012 is better than that of 2006. From the policy level, in order to reduce loss, government should maintain communication smoothly, improve the ability of self and mutual help, strengthen the management of public opinion, and pay more attention to secondary disasters.展开更多
In this paper, a game model composed of three subjects — government, manufacturer and consumer has been built by using Evolutionary Game Theory on the basis of analyzing the trilateral game strategy of waste mobile r...In this paper, a game model composed of three subjects — government, manufacturer and consumer has been built by using Evolutionary Game Theory on the basis of analyzing the trilateral game strategy of waste mobile reverse supply chain based on ECP; an evolutionary equilibrium model is to be sought for by utilizing the replication dynamic differential equation method; and the trilateral game strategy’s revolutionary trend and consistency have been analyzed by means of SD simulation method when government implements the static or dynamic reward and punishment strategy. The finding results reveal that, under the static reward and punishment strategy, the revolutionary process of trilateral game strategy is always unstable whether the initial behavior strategy is unitary or mixed.Therefore, it is more reasonable for the government to adopt the strategy of dynamic reward and punishment, and it is also stable and reciprocal for all the stakeholders when implementing this strategy.展开更多
基金supported by the Key Project of the National Natural Science Foundation of China “the SD model and threshold value prediction of the interactive coupled effects between urbanization and eco-environment in mega-urban agglomerations” (Grant No. 41590844)the Independent Research Program of Tsinghua University (Grant No. 2015THZ01)
文摘Is Chinese urbanization going to take a long time, or can its development goal be achieved by the government in a short time? What is the highest stable urbanization level that China can reach? When can China complete its urbanization? To answer these questions, this paper presents a system dynamic(SD) model of Chinese urbanization, and its validity and simulation are justified by a stock-flow test and a sensitivity analysis using real data from 1998 to 2013. Setting the initial conditions of the simulation by referring to the real data of 2013, the multi-scenario analysis from 2013 to 2050 reveals that Chinese urbanization will reach a level higher than 70% in 2035 and then proceed to a slow urbanization stage regardless of the population policy and GDP growth rate settings; in 2050, Chinese urbanization levels will reach approximately 75%, which is a stable and equilibrium level for China. Thus, it can be argued that Chinese urbanization is a long social development process that will require approximately20 years to complete and that the ultimate urbanization level will be 75–80%, which means that in the distant future, 20–25% of China's population will still settle in rural regions of China.
基金Under the auspices of National Natural Science Foundation of China(No.41171099)National Key Basic Research Program of China(No.2012CB955802)National Social Science Foundation of China(No.10ZD&022)
文摘The economic growth of China has led to increasing growth disparities between regions. Such disparities are uncontrolled and are severely negative symptoms in the process of economic development. On the basis of system dynamics(SD) modeling and the relationship between industrial relocation and regional economic growth, we construct a model of the interrelationship between the two aforementioned phenomena. The model is an effective and creative exploration for examining effects of industrial relocation on Chinese regional economic growth disparities. The SD model is employed in this study to build an inter-regional labor migration SD model, an inter-regional capital migration SD model, an intra-industry SD model, an intra-regional population SD model, and an intra-regional SD model which are based on realities in labor and capital flow from the view of industrial relocation. VENSIM software is utilized to perform a system simulation based on the data of the eastern, middle, and western regions from 2000 to 2010. Results show that industrial relocation gradually narrows the relative disparity in GDP among the three regions. Moreover, the absolute one is enlarged continuously. The absolute and relative disparities in per capita GDP among eastern, middle, and western regions generally exhibit decreasing trends.
基金National Natural Science Foundation of China,No.42071153Priority Research Program of Chinese Academy of Sciences,No.XDA20080000。
文摘Since the implementation of the economic reform and opening up policy in 1978,China has miraculously created long-term high-speed economic growth,but has also had to face the problem of excessive consumption of resources as well as an intensification of environmental pollution.As a result,China is now facing a slowdown in development.China must maintain a certain speed of development to realize its goal of being a powerful nation,and becoming a developed country by 2050.To this end,China is facing a transformation of its economic development.There is a need to agree on an expected economic growth rate,along with the corresponding development modes or means of regulation in the medium-and long-term periods.This study developed a systematic-dynamic model to simulate the coupling relationship between economic growth,development modes,and the environmental supply system,and explored the possible options for future economic growth as well as the resource use and environmental protection requirements(the main factors).The results showed that to achieve the development goal of becoming a developed country by 2050,while maintaining a good ecological environment,the suitable growth rate for China's economy is 3.8%–6.3%.Within this range,a growth rate of 3.8%–4.4%was found to be relatively safe,while a growth rate of 4.4%–6.3%required further technical progress.This study provides an early warning in regard to China's environmental and development status.The study was a response to the"Future Earth"framework document and,in terms of development speed,it developed a theoretical system for the determination of resource and environmental carrying capacity(RECC).
基金Financial support for this work,provided by the Priority Academic Program Development of Jiangsu Higher Education Institutions(No.SZBF2011-6-B35)the Research Fund for the Doctoral Program of Higher Education of China(No.20120095120017)the National High Technology Research and Development Program of China(No.2012AA062101)
文摘Fully mechanized mining with large mining height(FMMLMH)is widely used in thick coal seam mining face for its higher recovery ratio,especially where the thickness is less than 7.0 m.However,because of the great mining height and intense rock pressure,the coal wall rib spalling,roof falling and the instability of support occur more likely in FMMLMH working face,and the above three types of disasters interact with each other with complicated relationships.In order to get the relationship between each two of coal wall,roof,floor and support,and reduce the occurrence probability of the three types of disasters,we established the system dynamics(SD)model of the support-surrounding rock system which is composed of"coal wall-roof-floor-support"(CW-R-F-S)in a FMMLMH working face based on the condition of No.15104 working face in Sijiazhuang coal mine.With the software of Vensim,we also simulated the interaction process between each two factors of roof,floor,coal wall and the support.The results show that the SD model of"CW-R-F-S"system can reveal the complicated and interactive relationship clearly between the support and surrounding rock in the FMMLMH working face.By increasing the advancing speed of working face,the support resistance or the length of support guard,or by decreasing the tipto-face distance,the stability of"CW-R-F-S"system will be higher and the happening probability of the disasters such as coal wall rib spalling,roof falling or the instability of support will be lower.These research findings have been testified in field application in No.15104 working face,which can provide a new approach for researching the interaction relationship of support and surrounding rock.
文摘System dynamics (SD) theory has long been deployed in modeling complex non-linear interrelationships but, so far it has not been common to do the kind of modeling in support of bringing environmental sustainability policies to practice. This is largely because the challenge of including spatial data has not yet been well met. Potential for adoption of SD and GIS methods in combination is exemplified with the results of a decision-support exercise designed for simulation and prediction of the dynamic inter-relationships between socio-economic development and environmental quality for the "Wen, Pi, Du" county in Sichuan province, southwestern China.
基金supported by the National Basic Research Program of China (Contract No. 91125019)National Natural Science Foundation of China (Contract Nos.40971291,40901291)
文摘Land use/cover change （LUCC） models are helpful tools for analyzing driving forces and processes of land use changes, assessing ecological impacts of land use change and decision-making for land use planning. However, no single model is able to capture all the essential key processes to explore land use change at different spatial-temporal scales and make a full assessment of driving factors and macro-ecological impacts. Taken Ganzhou District as a case study, this paper describes an integrated analysis （IA） ap- proach by combining with system dynamics （SD） model, the Conversion of Land Use and its Effects at Small regional extent （CLUE-S） model and landscape indices method to analyze land use dynamics at different spatial-temporal scales. The SD model was used to calculate and predict demands for different land use types at the macro-scale as a whole during 2000-2035. The LUCC process was simulated at a high spatial resolution with the spatial consideration of land use spatial policies and restrictions to satisfy the balance between land use demand and supply by using the CLUE-S model, and Kappa values of the map simulation are 0.86 and 0.81 in 2000 and 2005, respectively. Finally, we evaluated the macro-ecological effect of LUCC and optimized sce- nario managements of land use by using landscape indices method. The IA approach could be used for better understanding the complexity of land use change and provide scientific support for land use planning and management, and the simulation results also could be used as a source data for scenario analysis of different hydrological and ecological processes based on different un- derlying surface of LUCC.
文摘A series of advantages of single difference (SD) and undifferenced (ZD) models are given as compared with the double difference (DD) model. However, rank defects exist in SD and ZD models. The reparameterization method is provided to resolve this rank defect problem by estimating some combinations of the unknowns rather than the unknowns themselves. The reparameterization of SD and ZD functional models is discussed in detail with their stochastic models. The theoretical confirmation of the equivalence of undifferenced and differenced models is described in a straightforward way. The relationship between SD and ZD residuals is given and verified for some special purposes, e.g. research on the stochastical properties of GPS observations.
基金Supported by National Natural Science Foundation of China(91224007)
文摘Based on the system dynamics(SD) model, this paper puts forward a quantitative method to evaluate the earthquake emergency plan in China. Firstly, we analyze the disaster system structure and the content of plan. Using the analysis results, we establish a system dynamics(SD) model and then carry out its simulation. According to the simulation results, the rescue effect using the plan of 2012 is better than that of 2006. From the policy level, in order to reduce loss, government should maintain communication smoothly, improve the ability of self and mutual help, strengthen the management of public opinion, and pay more attention to secondary disasters.
文摘In this paper, a game model composed of three subjects — government, manufacturer and consumer has been built by using Evolutionary Game Theory on the basis of analyzing the trilateral game strategy of waste mobile reverse supply chain based on ECP; an evolutionary equilibrium model is to be sought for by utilizing the replication dynamic differential equation method; and the trilateral game strategy’s revolutionary trend and consistency have been analyzed by means of SD simulation method when government implements the static or dynamic reward and punishment strategy. The finding results reveal that, under the static reward and punishment strategy, the revolutionary process of trilateral game strategy is always unstable whether the initial behavior strategy is unitary or mixed.Therefore, it is more reasonable for the government to adopt the strategy of dynamic reward and punishment, and it is also stable and reciprocal for all the stakeholders when implementing this strategy.
