This study,based on the current status and challenges of medical graduate education,explores innovative pathways for the coordinated development of research and clinical training under a dual-track integration model.B...This study,based on the current status and challenges of medical graduate education,explores innovative pathways for the coordinated development of research and clinical training under a dual-track integration model.By analyzing survey data and integrating cutting-edge educational concepts,a series of specific reform recommendations is proposed.The aim is to promote the upgrading and innovation of medical graduate training models,facilitate the integration of clinical practice and research,and provide strong support for the comprehensive development of medical graduates.展开更多
This paper presents a robust finite-time visual servo control strategy for the tracking problem of omni-directional mobile manipulators(OMMs)subject to mismatched disturbances.First,the nonlinear kinematic model of vi...This paper presents a robust finite-time visual servo control strategy for the tracking problem of omni-directional mobile manipulators(OMMs)subject to mismatched disturbances.First,the nonlinear kinematic model of visual servoing for OMMs with mismatched disturbances is explicitly presented to solve the whole-body inverse kinematic problem.Second,a sliding mode observer augmented with an integral terminal sliding mode controller is proposed to handle these uncertainties and ensure that the system converges to a small region around the equilibrium point.The boundary layer technique is employed to mitigate the chattering phenomenon.Furthermore,a strict finite-time Lyapunov stability analysis is conducted.An experimental comparison between the proposed algorithm and a traditional position-based visual servo controller is carried out,and the results demonstrate the superiority of the proposed control algorithm.展开更多
In this article,the mode superposition method is combined with a time integration method like the trapezoidal rule to improve solution accuracy for linear dynamic systems.In this combination strategy,the essential thi...In this article,the mode superposition method is combined with a time integration method like the trapezoidal rule to improve solution accuracy for linear dynamic systems.In this combination strategy,the essential thing is to decompose a dynamic system into two sub-systems,a small-scale low-frequency system and a high-frequency system.The former can be analytically and efficiently solved with the mode superposition method,and the latter is dealt with through a time integration method such as the Newmark method.The summation of the responses of these two sub-systems is the responses of the original dynamic system.It is concluded that,with little sacrifice of efficiency,the combination method based on the strategy is more accurate than the combined time integration method,but it has the same accuracy order as that of the combined method.Numerical experiments validate the effectiveness of the proposed strategy.展开更多
Taking landscape design of Suburban Park in Yulin City for example, this paper applied the design thoughts of integrating multiple planning, defining concepts and objectives, specified the design strategies of restori...Taking landscape design of Suburban Park in Yulin City for example, this paper applied the design thoughts of integrating multiple planning, defining concepts and objectives, specified the design strategies of restoring ecology, improving life and promoting production, and disclosed the landscape design mode based on the integration of ecology, production and life in which ecological landscapes, productive landscapes and living landscapes promote and coexist harmoniously with each other.展开更多
Taking the Zhejiang Academy of Agricultural Sciences as an example,the modes and approaches of combing industry-universities-research institutions to promote rural revitalization by agricultural scientific research un...Taking the Zhejiang Academy of Agricultural Sciences as an example,the modes and approaches of combing industry-universities-research institutions to promote rural revitalization by agricultural scientific research units are discussed.The main approaches are as follows:focusing on practical technical training to promote the transformation of scientific and technological achievements,transferring scientific and technological achievements to promote the deep integration of basic research,applied research and achievement transformation,and using the agronomist college as a carrier to promote the integrated development of industry-universities-research institutions and promote rural revitalization through systematic personnel training.展开更多
With the rapid development of information technology, it appears that a single online channel or a single offline is not able to meet the consumers＇ shopping needs, the enterprises will have a better development only...With the rapid development of information technology, it appears that a single online channel or a single offline is not able to meet the consumers＇ shopping needs, the enterprises will have a better development only by making the online and offline channels be in fusion and promote each other. This paper will combine the general business modes with corporate channel integration pattern, build out different forms of the market mode including market, enterprise and customers basing on different influence level, and analyze out the enterprise how to implement the business mode of integration basing on the influence factors under the background of different business modes, then apply the corresponding O2O process to the mode, so as to broaden the enterprise selling channels for a better development.展开更多
With the rapid development of information technology, it appears that a single online channel or a single offline is not able to meet the consumers＇ shopping needs, the enterprises will have a better development only...With the rapid development of information technology, it appears that a single online channel or a single offline is not able to meet the consumers＇ shopping needs, the enterprises will have a better development only by making the online and offline channels be in fusion and promote each other. This paper will combine the general business modes with corporate channel integration pattern, build out different forms of the market mode including market, enterprise and customers basing on different influence level, and analyze out the enterprise how to implement the business mode of integration basing on the influence factors under the background of different business modes, then apply the corresponding O2O process to the mode, so as to broaden the enterprise selling channels for a better development.展开更多
In this paper, we conduct research on the construction mode of mechanical and electrical integration of intelligent control system based on the multi-agent technique. The development of the modem science and technolog...In this paper, we conduct research on the construction mode of mechanical and electrical integration of intelligent control system based on the multi-agent technique. The development of the modem science and technology has greatly promoted the cross of different subjects and infiltration, caused the technological transformation and revolution in the field of engineering. In the field of mechanical engineering, because of rapid development of microelectronics technology and computer technology to the mechanical industry and its mechanical and electrical integration, which is formed by the penetration of the technology of mechanical industry structure, product, organization, function and structure, mode of the production and management system, great changes have taken place in industrial production by the mechanical electrification ＂ushered in the development of＂ mechatronics ＂as the characteristics of the stage. Our research combines the multi-agent technique to propose the new paradigm for mechanical and electrical integration which is innovative.展开更多
Merger is a kind of strategic behavior of seeking long-term development. A new enterprise coming from merger is different from the one that come into existence. The strategy of new enterprise formed from merger is con...Merger is a kind of strategic behavior of seeking long-term development. A new enterprise coming from merger is different from the one that come into existence. The strategy of new enterprise formed from merger is constituted through the integration of the strategy for each side. Strategy integration is the guide for the integration of other elements after merger, the way for enterprises to adapt the change of environment and the warranty for the enterprises to achieve strategy synergistic effect. Strategy integration of the merging-enterprises can be realized through several steps： preparation for strategy integration, readjustment to strategy, reorientation of the enterprise and effective communication with target enterprise in the course of carrying out the strategy.展开更多
With the continuous progress of the society and the rapid development of the industry,the talent training mode of early education has become an important commodity of education reform.Under the background of the integ...With the continuous progress of the society and the rapid development of the industry,the talent training mode of early education has become an important commodity of education reform.Under the background of the integration of industry and education,the training direction of early education professionals needs to be adjusted and planned.The practice of industry-education integration requires the deep combination of early education specialty with early education institutions and the technical standards of the equivalent industry,so as to build a high-quality platform for the growth of early education professionals.This paper focuses on the current situation of the integration of industry and education,and then makes an in-depth analysis on several reform strategies,so as to lay a solid foundation for the training of early education talents.展开更多
During the 14th Five Year Plan period,the main task of talent team construction in China’s asset appraisal industry was to develop innovative talent training models.Therefore,this article focuses on the talent cultiv...During the 14th Five Year Plan period,the main task of talent team construction in China’s asset appraisal industry was to develop innovative talent training models.Therefore,this article focuses on the talent cultivation model of integrating industry and education in asset evaluation in universities,systematically summarizes the theoretical and practical significance of research on asset evaluation talent cultivation models in universities,and explores the construction measures of asset evaluation talent cultivation models based on the integration of industry and education that meet social needs and the development of the times[1].At the same time,the strategy of constructing a deep integration talent training system was explored,guided by the integration of industry and education,to cultivate asset evaluation composite talents with strong practical skills.The aim is to provide a reference for improving the quality of asset evaluation professionals in China and promoting the development of asset evaluation talent training models.展开更多
The connotation of urban-rural integration,its construction courses,construction modes in China and abroad are introduced in this study,the problems emerging from the urban-rural integration practices are analyzed,and...The connotation of urban-rural integration,its construction courses,construction modes in China and abroad are introduced in this study,the problems emerging from the urban-rural integration practices are analyzed,and strategies for the urban-rural integration in China are proposed.展开更多
In view of lake scenic areas with abundant tourist resources but less-developed economy,contradictions between the urgency of its tourist resource development and complexity of urban-rural planning compilation were an...In view of lake scenic areas with abundant tourist resources but less-developed economy,contradictions between the urgency of its tourist resource development and complexity of urban-rural planning compilation were analyzed,and also limitations summarized as insufficient time and fund.Statutory planning contents included in the integrated compilation system were elaborated,and compilation of the integrated planning for the Longhe Lake Scenic Area in the Taihang Mountains was taken for example to introduce planning concepts of the compilation technical system.Considering characteristics of the study area,"regionality" was stressed as the foundation of planning compilation,concise,convenient and practical planning compilation contents were advocated and further explained from the perspectives of compiling by layer and category.In view of this,it is necessary to apply integrated compilation mode under certain circumstances,so as to provide a new approach for the planning compilation of other regions in China and enhance economic and social development of local areas.展开更多
For the terminal guidance problem of missiles intercepting maneuvering targets in the three-dimensional space, the design of guidance laws for non-decoupling three-dimensional engage- ment geometry is studied. Firstly...For the terminal guidance problem of missiles intercepting maneuvering targets in the three-dimensional space, the design of guidance laws for non-decoupling three-dimensional engage- ment geometry is studied. Firstly, by introducing a finite time integral sliding mode manifold, a novel guidance law based on the integral sliding mode control is presented with the target acceler- ation as a known bounded external disturbance. Then, an improved adaptive guidance law based on the integral sliding mode control without the information of the upper bound on the target accel- eration is developed, where the upper bound of the target acceleration is estimated online by a designed adaptive law. The both presented guidance laws can make sure that the elevation angular rate of the line-of-sight and the azimuth angular rate of the line-of-sight converge to zero in finite time. In the end, the results of the guidance performance for the proposed guidance laws are pre- sented by numerical simulations. Although the designed guidance laws are developed for the con- stant speed missiles, the simulation results for the time-varying speed missiles are also shown to further confirm the designed guidance laws.展开更多
A fault tolerant control （FTC） design technique against actuator stuck faults is investigated using integral-type sliding mode control （ISMC） with application to spacecraft attitude maneuvering control system. The...A fault tolerant control （FTC） design technique against actuator stuck faults is investigated using integral-type sliding mode control （ISMC） with application to spacecraft attitude maneuvering control system. The principle of the proposed FTC scheme is to design an integral-type sliding mode attitude controller using on-line parameter adaptive updating law to compensate for the effects of stuck actuators. This adaptive law also provides both the estimates of the system parameters and external disturbances such that a prior knowledge of the spacecraft inertia or boundedness of disturbances is not required. Moreover, by including the integral feedback term, the designed controller can not only tolerate actuator stuck faults, but also compensate the disturbances with constant components. For the synthesis of controller, the fault time, patterns and values are unknown in advance, as motivated from a practical spacecraft control application. Complete stability and performance analysis are presented and illustrative simulation results of application to a spacecraft show that high precise attitude control with zero steady-error is successfully achieved using various scenarios of stuck failures in actuators.展开更多
Over the past two decades, numerous ports located in China have participated in port integration strategies, thus influencing the entire port system. The current research is initiated in order to examine the nature of...Over the past two decades, numerous ports located in China have participated in port integration strategies, thus influencing the entire port system. The current research is initiated in order to examine the nature of port integration in China, including associated temporal pathways, spatial patterns and dynamics. Results indicate that port integration in China has been characterized by a significant increase at the turn of the 21 st century, comprising thirteen distinguishable pathways typified by differing dynamics, particularly between the northern and southern ports. Pathways were found to include 44 seaports and river ports, chiefly concentrated in the Bohai Rim, Yangtze(Changjiang) River Delta, Beibu Gulf and the southeastern Fujian, thus representing significant spatial regions. Categorically larger seaports have become the primary beneficiaries of port integration. Integration cases were divided into four categories based upon quantified dynamic magnitude including the government-driven mode, market-driven mode, government/market-driven mode and strategic alliance, and into five further categories based upon spatial extent including port internal integration, jurisdictional port integration, port integration across neighbor region, regional port integration and hub-feeder port integration. Results suggest that several factors have effectively driven port integration in China, including legislative tools and spatial planning, optimization of shoreline resources and port functionality, and port competition with the same hinterland.展开更多
Aimed at the guidance requirements of some missiles which attack targets with terminal impact angle at the terminal point,a new integrated guidance and control design scheme based on variable structure control approac...Aimed at the guidance requirements of some missiles which attack targets with terminal impact angle at the terminal point,a new integrated guidance and control design scheme based on variable structure control approach for missile with terminal impact angle constraint is proposed.First,a mathematical model of an integrated guidance and control model in pitch plane is established,and then nonlinear transformation is employed to transform the mathematical model into a standard form suitable for sliding mode control method design.A sufficient condition for the existence of linear sliding surface is given in terms of linear matrix inequalities（LMIs）,based on which the corresponding reaching motion controller is also developed.To verify the effectiveness of the proposed integrated design scheme,the numerical simulation of missile is made.The simulation results demonstrate that the proposed guidance and control law can guide missile to hit the target with desired impact angle and desired flight attitude angle simultaneously.展开更多
An integral sliding mode guidance law(ISMGL)combined with the advantages of the integral sliding mode control(SMC)method is designed to address maneuvering target interception problems with impact angle constraints.Th...An integral sliding mode guidance law(ISMGL)combined with the advantages of the integral sliding mode control(SMC)method is designed to address maneuvering target interception problems with impact angle constraints.The relative motion equation of the missile and the target considering the impact angle constraint is established in the longitudinal plane,and an integral sliding mode surface is constructed.The proposed guidance law resolves the existence of a steady-state error problem in the traditional SMC.Such a guidance law ensures that the missile hits the target with an ideal impact angle in finite time and the missile is kept highly robust throughout the interception process.By adopting the dynamic surface control method,the ISMGL is designed considering the impact angle constraints and the autopilot dynamic characteristics.According to the Lyapunov stability theorem,all states of the closed-loop system are finally proven to be uniformly bounded.Simulation results are compared with the general sliding mode guidance law and the trajectory shaping guidance law,and the findings verify the effectiveness and superiority of the ISMGL.展开更多
The nuclear power plant is suitable for base-load operation, while the pumped-storage unit mainly gives play to capacity benefit in the electric power system;hence, the integrated development and hybrid operation mode...The nuclear power plant is suitable for base-load operation, while the pumped-storage unit mainly gives play to capacity benefit in the electric power system;hence, the integrated development and hybrid operation mode of the two can better meet the needs of the electric power system. This article first presents an analysis of the necessity and superiority of such mode, then explains its meaning and analyzes the working routes. Finally, it proposes the business modes as follows: low price pumping water electricity plus nuclear power in the near term;nuclear power shifted to pumped storage power participating in market competition in the middle term;and, in the long term, nuclear power shifted to pumped storage power as primary and serving as an electric power system when needed.展开更多
基金Key Project of Postgraduate Education and Teaching Reform in Chongqing(yjg222018)。
文摘This study,based on the current status and challenges of medical graduate education,explores innovative pathways for the coordinated development of research and clinical training under a dual-track integration model.By analyzing survey data and integrating cutting-edge educational concepts,a series of specific reform recommendations is proposed.The aim is to promote the upgrading and innovation of medical graduate training models,facilitate the integration of clinical practice and research,and provide strong support for the comprehensive development of medical graduates.
基金supported by the Artificial Intelligence Innovation and Development Special Fund of Shanghai(No.2019RGZN01041)the National Natural Science Foundation of China(No.92048205).
文摘This paper presents a robust finite-time visual servo control strategy for the tracking problem of omni-directional mobile manipulators(OMMs)subject to mismatched disturbances.First,the nonlinear kinematic model of visual servoing for OMMs with mismatched disturbances is explicitly presented to solve the whole-body inverse kinematic problem.Second,a sliding mode observer augmented with an integral terminal sliding mode controller is proposed to handle these uncertainties and ensure that the system converges to a small region around the equilibrium point.The boundary layer technique is employed to mitigate the chattering phenomenon.Furthermore,a strict finite-time Lyapunov stability analysis is conducted.An experimental comparison between the proposed algorithm and a traditional position-based visual servo controller is carried out,and the results demonstrate the superiority of the proposed control algorithm.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.11872090 and 12172023).
文摘In this article,the mode superposition method is combined with a time integration method like the trapezoidal rule to improve solution accuracy for linear dynamic systems.In this combination strategy,the essential thing is to decompose a dynamic system into two sub-systems,a small-scale low-frequency system and a high-frequency system.The former can be analytically and efficiently solved with the mode superposition method,and the latter is dealt with through a time integration method such as the Newmark method.The summation of the responses of these two sub-systems is the responses of the original dynamic system.It is concluded that,with little sacrifice of efficiency,the combination method based on the strategy is more accurate than the combined time integration method,but it has the same accuracy order as that of the combined method.Numerical experiments validate the effectiveness of the proposed strategy.
基金Sponsored by National Natural Science Foundation of China(51178372/E080201)Humanities and Social Science Program of Northwest A&F University(2015RWYB38)
文摘Taking landscape design of Suburban Park in Yulin City for example, this paper applied the design thoughts of integrating multiple planning, defining concepts and objectives, specified the design strategies of restoring ecology, improving life and promoting production, and disclosed the landscape design mode based on the integration of ecology, production and life in which ecological landscapes, productive landscapes and living landscapes promote and coexist harmoniously with each other.
基金Science and Technology Planning Project of Zhejiang Province(2018C02057,2018C02055)National Rice Industry Technology System(CARS-01-48).
文摘Taking the Zhejiang Academy of Agricultural Sciences as an example,the modes and approaches of combing industry-universities-research institutions to promote rural revitalization by agricultural scientific research units are discussed.The main approaches are as follows:focusing on practical technical training to promote the transformation of scientific and technological achievements,transferring scientific and technological achievements to promote the deep integration of basic research,applied research and achievement transformation,and using the agronomist college as a carrier to promote the integrated development of industry-universities-research institutions and promote rural revitalization through systematic personnel training.
文摘With the rapid development of information technology, it appears that a single online channel or a single offline is not able to meet the consumers＇ shopping needs, the enterprises will have a better development only by making the online and offline channels be in fusion and promote each other. This paper will combine the general business modes with corporate channel integration pattern, build out different forms of the market mode including market, enterprise and customers basing on different influence level, and analyze out the enterprise how to implement the business mode of integration basing on the influence factors under the background of different business modes, then apply the corresponding O2O process to the mode, so as to broaden the enterprise selling channels for a better development.
文摘With the rapid development of information technology, it appears that a single online channel or a single offline is not able to meet the consumers＇ shopping needs, the enterprises will have a better development only by making the online and offline channels be in fusion and promote each other. This paper will combine the general business modes with corporate channel integration pattern, build out different forms of the market mode including market, enterprise and customers basing on different influence level, and analyze out the enterprise how to implement the business mode of integration basing on the influence factors under the background of different business modes, then apply the corresponding O2O process to the mode, so as to broaden the enterprise selling channels for a better development.
文摘In this paper, we conduct research on the construction mode of mechanical and electrical integration of intelligent control system based on the multi-agent technique. The development of the modem science and technology has greatly promoted the cross of different subjects and infiltration, caused the technological transformation and revolution in the field of engineering. In the field of mechanical engineering, because of rapid development of microelectronics technology and computer technology to the mechanical industry and its mechanical and electrical integration, which is formed by the penetration of the technology of mechanical industry structure, product, organization, function and structure, mode of the production and management system, great changes have taken place in industrial production by the mechanical electrification ＂ushered in the development of＂ mechatronics ＂as the characteristics of the stage. Our research combines the multi-agent technique to propose the new paradigm for mechanical and electrical integration which is innovative.
文摘Merger is a kind of strategic behavior of seeking long-term development. A new enterprise coming from merger is different from the one that come into existence. The strategy of new enterprise formed from merger is constituted through the integration of the strategy for each side. Strategy integration is the guide for the integration of other elements after merger, the way for enterprises to adapt the change of environment and the warranty for the enterprises to achieve strategy synergistic effect. Strategy integration of the merging-enterprises can be realized through several steps： preparation for strategy integration, readjustment to strategy, reorientation of the enterprise and effective communication with target enterprise in the course of carrying out the strategy.
文摘With the continuous progress of the society and the rapid development of the industry,the talent training mode of early education has become an important commodity of education reform.Under the background of the integration of industry and education,the training direction of early education professionals needs to be adjusted and planned.The practice of industry-education integration requires the deep combination of early education specialty with early education institutions and the technical standards of the equivalent industry,so as to build a high-quality platform for the growth of early education professionals.This paper focuses on the current situation of the integration of industry and education,and then makes an in-depth analysis on several reform strategies,so as to lay a solid foundation for the training of early education talents.
文摘During the 14th Five Year Plan period,the main task of talent team construction in China’s asset appraisal industry was to develop innovative talent training models.Therefore,this article focuses on the talent cultivation model of integrating industry and education in asset evaluation in universities,systematically summarizes the theoretical and practical significance of research on asset evaluation talent cultivation models in universities,and explores the construction measures of asset evaluation talent cultivation models based on the integration of industry and education that meet social needs and the development of the times[1].At the same time,the strategy of constructing a deep integration talent training system was explored,guided by the integration of industry and education,to cultivate asset evaluation composite talents with strong practical skills.The aim is to provide a reference for improving the quality of asset evaluation professionals in China and promoting the development of asset evaluation talent training models.
文摘The connotation of urban-rural integration,its construction courses,construction modes in China and abroad are introduced in this study,the problems emerging from the urban-rural integration practices are analyzed,and strategies for the urban-rural integration in China are proposed.
文摘In view of lake scenic areas with abundant tourist resources but less-developed economy,contradictions between the urgency of its tourist resource development and complexity of urban-rural planning compilation were analyzed,and also limitations summarized as insufficient time and fund.Statutory planning contents included in the integrated compilation system were elaborated,and compilation of the integrated planning for the Longhe Lake Scenic Area in the Taihang Mountains was taken for example to introduce planning concepts of the compilation technical system.Considering characteristics of the study area,"regionality" was stressed as the foundation of planning compilation,concise,convenient and practical planning compilation contents were advocated and further explained from the perspectives of compiling by layer and category.In view of this,it is necessary to apply integrated compilation mode under certain circumstances,so as to provide a new approach for the planning compilation of other regions in China and enhance economic and social development of local areas.
基金financial support provided by the National Natural Science Foundation of China(Nos.61174037 and 61021002)the Aeronautical Science Foundation of China(No.20140177002)
文摘For the terminal guidance problem of missiles intercepting maneuvering targets in the three-dimensional space, the design of guidance laws for non-decoupling three-dimensional engage- ment geometry is studied. Firstly, by introducing a finite time integral sliding mode manifold, a novel guidance law based on the integral sliding mode control is presented with the target acceler- ation as a known bounded external disturbance. Then, an improved adaptive guidance law based on the integral sliding mode control without the information of the upper bound on the target accel- eration is developed, where the upper bound of the target acceleration is estimated online by a designed adaptive law. The both presented guidance laws can make sure that the elevation angular rate of the line-of-sight and the azimuth angular rate of the line-of-sight converge to zero in finite time. In the end, the results of the guidance performance for the proposed guidance laws are pre- sented by numerical simulations. Although the designed guidance laws are developed for the con- stant speed missiles, the simulation results for the time-varying speed missiles are also shown to further confirm the designed guidance laws.
基金National Natural Science Foundation of China(61004072)Fundamental Research Funds for the Central Universities(HIT.NSRIF.2009003)+1 种基金Research Fund for the Doctoral Program of Higher Education of China (20070213061, 20102302110031)Scientific Research Foundation for the Returned Overseas Chinese Scholars of Harbin (2010RFLXG001)
文摘A fault tolerant control （FTC） design technique against actuator stuck faults is investigated using integral-type sliding mode control （ISMC） with application to spacecraft attitude maneuvering control system. The principle of the proposed FTC scheme is to design an integral-type sliding mode attitude controller using on-line parameter adaptive updating law to compensate for the effects of stuck actuators. This adaptive law also provides both the estimates of the system parameters and external disturbances such that a prior knowledge of the spacecraft inertia or boundedness of disturbances is not required. Moreover, by including the integral feedback term, the designed controller can not only tolerate actuator stuck faults, but also compensate the disturbances with constant components. For the synthesis of controller, the fault time, patterns and values are unknown in advance, as motivated from a practical spacecraft control application. Complete stability and performance analysis are presented and illustrative simulation results of application to a spacecraft show that high precise attitude control with zero steady-error is successfully achieved using various scenarios of stuck failures in actuators.
基金Under the auspices of National Natural Science Foundation of China(No.41171108)Key Program of Chinese Academy of Sciences(No.KZZD-EW-06-02)Exploratory Forefront Project for the Strategic Science Plan in IGSNRR,CAS(No.2012QY004)
文摘Over the past two decades, numerous ports located in China have participated in port integration strategies, thus influencing the entire port system. The current research is initiated in order to examine the nature of port integration in China, including associated temporal pathways, spatial patterns and dynamics. Results indicate that port integration in China has been characterized by a significant increase at the turn of the 21 st century, comprising thirteen distinguishable pathways typified by differing dynamics, particularly between the northern and southern ports. Pathways were found to include 44 seaports and river ports, chiefly concentrated in the Bohai Rim, Yangtze(Changjiang) River Delta, Beibu Gulf and the southeastern Fujian, thus representing significant spatial regions. Categorically larger seaports have become the primary beneficiaries of port integration. Integration cases were divided into four categories based upon quantified dynamic magnitude including the government-driven mode, market-driven mode, government/market-driven mode and strategic alliance, and into five further categories based upon spatial extent including port internal integration, jurisdictional port integration, port integration across neighbor region, regional port integration and hub-feeder port integration. Results suggest that several factors have effectively driven port integration in China, including legislative tools and spatial planning, optimization of shoreline resources and port functionality, and port competition with the same hinterland.
基金supported by the Nationa Natural Science Foundation of China(60434010)Outstanding Youth Fund of Heilongjiang Province(JC200606)
文摘Aimed at the guidance requirements of some missiles which attack targets with terminal impact angle at the terminal point,a new integrated guidance and control design scheme based on variable structure control approach for missile with terminal impact angle constraint is proposed.First,a mathematical model of an integrated guidance and control model in pitch plane is established,and then nonlinear transformation is employed to transform the mathematical model into a standard form suitable for sliding mode control method design.A sufficient condition for the existence of linear sliding surface is given in terms of linear matrix inequalities（LMIs）,based on which the corresponding reaching motion controller is also developed.To verify the effectiveness of the proposed integrated design scheme,the numerical simulation of missile is made.The simulation results demonstrate that the proposed guidance and control law can guide missile to hit the target with desired impact angle and desired flight attitude angle simultaneously.
基金supported by the Joint Equipment Fund of the Ministry of Education(6141A02022340)
文摘An integral sliding mode guidance law(ISMGL)combined with the advantages of the integral sliding mode control(SMC)method is designed to address maneuvering target interception problems with impact angle constraints.The relative motion equation of the missile and the target considering the impact angle constraint is established in the longitudinal plane,and an integral sliding mode surface is constructed.The proposed guidance law resolves the existence of a steady-state error problem in the traditional SMC.Such a guidance law ensures that the missile hits the target with an ideal impact angle in finite time and the missile is kept highly robust throughout the interception process.By adopting the dynamic surface control method,the ISMGL is designed considering the impact angle constraints and the autopilot dynamic characteristics.According to the Lyapunov stability theorem,all states of the closed-loop system are finally proven to be uniformly bounded.Simulation results are compared with the general sliding mode guidance law and the trajectory shaping guidance law,and the findings verify the effectiveness and superiority of the ISMGL.
基金funded by the Project “Resource Characteristics of Main Watersheds and Key Issues in Development and Utilization of Hydroelectricity in South America and Africa”the National Science Foundation of China (U1766201)
文摘The nuclear power plant is suitable for base-load operation, while the pumped-storage unit mainly gives play to capacity benefit in the electric power system;hence, the integrated development and hybrid operation mode of the two can better meet the needs of the electric power system. This article first presents an analysis of the necessity and superiority of such mode, then explains its meaning and analyzes the working routes. Finally, it proposes the business modes as follows: low price pumping water electricity plus nuclear power in the near term;nuclear power shifted to pumped storage power participating in market competition in the middle term;and, in the long term, nuclear power shifted to pumped storage power as primary and serving as an electric power system when needed.
