System dynamics model of the support-surrounding rock system in fully mechanized mining with large mining height face and its application

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.

An integrated analysis approach to LUCC at regional scale:A case study in the Ganzhou District of Zhangye City,China

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.

Evaluation of Earthquake Emergency Plan Based on SD Model

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.

Study on Participant Behavior Game of Electronic Products Reverse Supply Chain Based on ECP

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.

资源环境约束下中国经济增长可持续性模拟

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).