With the rapid improvement of urbanization and industrialization in countries around the world,how to effectively solve the rapid demise of traditional villages is a social dilemma faced by all countries,which is why ...With the rapid improvement of urbanization and industrialization in countries around the world,how to effectively solve the rapid demise of traditional villages is a social dilemma faced by all countries,which is why a series of relevant protection regulations have been promulgated in different historical periods.However,the formulation of relevant policies is still not scientific,universal,and long-term.In this study,we constructed an evolutionary game model of local governments and residents based on the evolutionary game theory(EGT),which is used to explore the evolutionary stability strategy(ESS)and stability conditions of stakeholders under the premise of mutual influence and restriction.Besides,the study also included the analysis about the impacts of different influence factors on the evolution tendency of the game model.At the same time,numerical simulation examples were used to verify the theoretical results and three crucial conclusions have been drawn.Firstly,the strategic evolution of stakeholders is a dynamic process of continuous adjustment and optimization,and its results and speed show consistent interdependence.Secondly,the decision-making of stakeholders mainly depends on the basic cost,and the high cost of investment is not conducive to the protection of traditional villages.Thirdly,the dynamic evolutionary mechanism composed of different influence factors will have an impact on the direction and speed of decision-making of stakeholders,which provides the basis for them to effectively restrict the decision-making of each other.This study eliminates the weaknesses of existing research approaches and provides scientific and novel ideas for the protection of traditional villages,which can contribute to the formulation and improvement of the relevant laws and regulations.展开更多
A nonlinear mathematical model for hydro turbine governing system with saturation nonlinearity in small perturbation has been proposed with all the essential components, i.e. turbine, PID t^^pe governor with saturatio...A nonlinear mathematical model for hydro turbine governing system with saturation nonlinearity in small perturbation has been proposed with all the essential components, i.e. turbine, PID t^^pe governor with saturation part and generator included in the model. Existence, stability and direction of Hopf bifurcation of an example HTGS are investigated in detail and presented in forms of bifurcation diagrams and time ＂wavefomis. The analysis show,that a supercritical Hopf bifurcation may exist in hydraulic turbine systems in some certain conditions. Moreover, the dynaiidc behavior of system with different parameters such as Tw, Tab, Ty and 尺 are studied extensively. An example with numerical simulations is presented to illustrate the theoretical results. The researches provide a reasonable explanation for the Hopf phenomenon happened in operation of hydroelectric generating unit.展开更多
Hydro-turbine governing system is a time-varying complex system with strong non-linearity,and its dynamic characteristics are jointly affected by hydraulic,mechanical,electrical,and other factors.Aiming at the stabili...Hydro-turbine governing system is a time-varying complex system with strong non-linearity,and its dynamic characteristics are jointly affected by hydraulic,mechanical,electrical,and other factors.Aiming at the stability of the hydroturbine governing system,this paper first builds a dynamic model of the hydro-turbine governing system through mechanism modeling,and introduces the transfer coefficient characteristics under different load conditions to obtain the stability category of the system.BP neural network is used to perform the machine study and the predictive analysis of the stability of the system under different working conditions is carried out by using the additional momentum method to optimize the algorithm.The test set results show that the method can accurately distinguish the stability category of the hydro-turbine governing system(HTGS),and the research results can provide a theoretical reference for the operation and management of smart hydropower stations in the future.展开更多
In this paper,we first examine the impact of governance quality on public expenditure efficiency.Then,we try to determine the effect of these expenditures on economic growth.Our starting point is the idea that public ...In this paper,we first examine the impact of governance quality on public expenditure efficiency.Then,we try to determine the effect of these expenditures on economic growth.Our starting point is the idea that public expenditure efficiency of a government program is significantly affected by the country’s governance quality.In other words,changes in government expenditure and the returns they generate on a government program depend on governance quality.Our sample consists of 36 countries observed over the 1996 to 2020 period.This period is known by a significant transition of political regimes.Our research model links government expenditure with the returns generated in a country in a given sector.In this model,we introduce the governance variable to examine the impact of government expenditure on returns on a government program in terms of schooling rates and life expectancy.The results indicate that governance quality affects expenditure structure and that efficiency of this expenditure positively correlates with a better governance quality as measured by corruption control and government efficiency.We also found that efficient expenditure has a positive impact on economic growth.展开更多
基金funded by the Southwest Minzu University 2021 Graduate Innovative Research Master Key Project(320-022142043).
文摘With the rapid improvement of urbanization and industrialization in countries around the world,how to effectively solve the rapid demise of traditional villages is a social dilemma faced by all countries,which is why a series of relevant protection regulations have been promulgated in different historical periods.However,the formulation of relevant policies is still not scientific,universal,and long-term.In this study,we constructed an evolutionary game model of local governments and residents based on the evolutionary game theory(EGT),which is used to explore the evolutionary stability strategy(ESS)and stability conditions of stakeholders under the premise of mutual influence and restriction.Besides,the study also included the analysis about the impacts of different influence factors on the evolution tendency of the game model.At the same time,numerical simulation examples were used to verify the theoretical results and three crucial conclusions have been drawn.Firstly,the strategic evolution of stakeholders is a dynamic process of continuous adjustment and optimization,and its results and speed show consistent interdependence.Secondly,the decision-making of stakeholders mainly depends on the basic cost,and the high cost of investment is not conducive to the protection of traditional villages.Thirdly,the dynamic evolutionary mechanism composed of different influence factors will have an impact on the direction and speed of decision-making of stakeholders,which provides the basis for them to effectively restrict the decision-making of each other.This study eliminates the weaknesses of existing research approaches and provides scientific and novel ideas for the protection of traditional villages,which can contribute to the formulation and improvement of the relevant laws and regulations.
文摘A nonlinear mathematical model for hydro turbine governing system with saturation nonlinearity in small perturbation has been proposed with all the essential components, i.e. turbine, PID t^^pe governor with saturation part and generator included in the model. Existence, stability and direction of Hopf bifurcation of an example HTGS are investigated in detail and presented in forms of bifurcation diagrams and time ＂wavefomis. The analysis show,that a supercritical Hopf bifurcation may exist in hydraulic turbine systems in some certain conditions. Moreover, the dynaiidc behavior of system with different parameters such as Tw, Tab, Ty and 尺 are studied extensively. An example with numerical simulations is presented to illustrate the theoretical results. The researches provide a reasonable explanation for the Hopf phenomenon happened in operation of hydroelectric generating unit.
文摘Hydro-turbine governing system is a time-varying complex system with strong non-linearity,and its dynamic characteristics are jointly affected by hydraulic,mechanical,electrical,and other factors.Aiming at the stability of the hydroturbine governing system,this paper first builds a dynamic model of the hydro-turbine governing system through mechanism modeling,and introduces the transfer coefficient characteristics under different load conditions to obtain the stability category of the system.BP neural network is used to perform the machine study and the predictive analysis of the stability of the system under different working conditions is carried out by using the additional momentum method to optimize the algorithm.The test set results show that the method can accurately distinguish the stability category of the hydro-turbine governing system(HTGS),and the research results can provide a theoretical reference for the operation and management of smart hydropower stations in the future.
文摘In this paper,we first examine the impact of governance quality on public expenditure efficiency.Then,we try to determine the effect of these expenditures on economic growth.Our starting point is the idea that public expenditure efficiency of a government program is significantly affected by the country’s governance quality.In other words,changes in government expenditure and the returns they generate on a government program depend on governance quality.Our sample consists of 36 countries observed over the 1996 to 2020 period.This period is known by a significant transition of political regimes.Our research model links government expenditure with the returns generated in a country in a given sector.In this model,we introduce the governance variable to examine the impact of government expenditure on returns on a government program in terms of schooling rates and life expectancy.The results indicate that governance quality affects expenditure structure and that efficiency of this expenditure positively correlates with a better governance quality as measured by corruption control and government efficiency.We also found that efficient expenditure has a positive impact on economic growth.
