Objective To propose a method to identify the shortest catch-up path by using patent data based on the perspective of technology leapfrogging so as to provide a reference for the catch-up strategy formulation by the g...Objective To propose a method to identify the shortest catch-up path by using patent data based on the perspective of technology leapfrogging so as to provide a reference for the catch-up strategy formulation by the governments of the developing countries.Methods Firstly,the international patent classification(IPC)co-occurrence network was used to screen key technologies,and the TOP 5 countries and China were located from the aspects of technology life cycle and technological innovation capabilities.Next,the technology development path based on the ordered clustering algorithm and the main IPC number was set up.Finally,the Dijkstra algorithm was applied to identify the shortest catch-up path.Results and Conclusion Applying this method to the current biopharmaceutical industry with the most potential for development,the shortest catch-up paths are found in the selected C12N15,C07K14 and C12Q1 technology fields,proving the feasibility of the method.展开更多
In the 10<sup>th</sup> Five-Year Plan for National Economic and Social Development （2001-05）,the centralauthorities announced that Chinawill adopt a ’leapfrogging’tactic forits technological developmen...In the 10<sup>th</sup> Five-Year Plan for National Economic and Social Development （2001-05）,the centralauthorities announced that Chinawill adopt a ’leapfrogging’tactic forits technological development. Butthe questions raised by Chinese sci-entists are:How this can展开更多
The Chinese Academy of Sci-ences (CAS) has begun introducingthe trial implementation of theKnowledge Innovation Program(KIP)in an all-round manner just as,at the beginning of the new century,the state is about to impl...The Chinese Academy of Sci-ences (CAS) has begun introducingthe trial implementation of theKnowledge Innovation Program(KIP)in an all-round manner just as,at the beginning of the new century,the state is about to implement itsTenth Five-Year Plan for thecountry’s ongoing economic andsocial development. This will展开更多
The realization of leapfrogging socio-economic development in the Tibet Autonomous Region remains a key issue in the current drive to develop Western China. In this connection, the CAS Academic Divisions have sponsore...The realization of leapfrogging socio-economic development in the Tibet Autonomous Region remains a key issue in the current drive to develop Western China. In this connection, the CAS Academic Divisions have sponsored a task force of a dozen CAS members and nearly 30 other experts to conduct comprehensive studies on the subject, and presented a feasibility study report to the central government. Some of their main ideas are as follows:展开更多
Rapid innovation and development of modern technology has brought about the opportunity for developing economies to technological leapfrog. In particular, rather than going through all the learning curve and costly pr...Rapid innovation and development of modern technology has brought about the opportunity for developing economies to technological leapfrog. In particular, rather than going through all the learning curve and costly process <span style="font-family:Verdana;">experienced by developed countries, emerging economies instead can tak</span><span style="font-family:Verdana;">e advantage of the opportunities presented by technological shifts. However, inadequate infrastructure is the cause of most challenges that these developing economies presently face. Energy, road, transport and telecommunication networks are the most critical infrastructure needed to drive a sustainable </span><span style="font-family:Verdana;">development and economic growth. As seen in many emerging economies, </span><span style="font-family:Verdana;">small private cars are still dominating the public transport sector, even though </span><span style="font-family:Verdana;">it is evident that they are congesting the poorly managed and crumbling road </span><span style="font-family:Verdana;">infrastructure. Most emerging economies’ cities are currently experiencing rapi</span><span style="font-family:Verdana;">d urbanisation that is leading to massive population explosion. These rapidly growing cities should adopt latest technologies, such as Trackless Trams Systems (TTS). There is no doubt that TTS can probably help in dealing with most of the transport problems experienced in rapidly growing urban areas </span><span style="font-family:Verdana;">within emerging economies. This paper seeks to explore the opportunities</span><span style="font-family:Verdana;"> presented by TTS to bring about the needed technological leapfrogging for the developing countries that are resource constrained to build modern and expensive mass public transport infrastructure. An ideal example of a recent successful technological leapfrog in emerging economies is the low-cost mo</span><span style="font-family:Verdana;">bile phones and increasingly expanding wireless access in urban areas. As </span><span style="font-family:Verdana;">such, countries have been able to eliminate the challenge of building fixed-line t</span><span style="font-family:Verdana;">elecommunications infrastructure, which is capital-intensive. In this study we are undertaking a literature appraisal on technological leapfrogging, and demonstrate how TTS measure up as a potential technology to aid the leap</span><span style="font-family:Verdana;">frogging for the urban transport systems more so in developing countries.</span><span style="font-family:Verdana;"> The study discusses the features, quality, and proficiencies of the new technology. To consider technology for leapfrogging, it ought to be economical enough, less technical, lends itself to partnership, lends itself to community </span><span style="font-family:Verdana;">engagement, allows co-development, and fulfils sustainable development goals (SDGs). The paper is organized into four sections, the introduction, litera</span><span style="font-family:Verdana;">ture appraisal, experiential evidence and debate on Trackless Trams, and </span><span style="font-family:Verdana;">conclu</span><span style="font-family:Verdana;">sion.</span>展开更多
Errors due to split time stepping are discussed for an explicit free–surface ocean model. In commonly used split time stepping, the way of time integration for the barotropic momentum equation is not compatible with ...Errors due to split time stepping are discussed for an explicit free–surface ocean model. In commonly used split time stepping, the way of time integration for the barotropic momentum equation is not compatible with that of the baroclinic one. The baroclinic equation has three–time–level structure because of leapfrog scheme. The barotropic one, however, has two–time–level structure when represented in terms of the baroclinic time level, on which the baroclinic one is integrated. This incompatibility results in the splitting errors as shown in this paper. The proper split time stepping is therefore proposed in such a way that the compatibility is kept between the barotropic and baroclinic equations. Its splitting errors are shown extremely small, so that it is particularly relevant to long–term integration for climate studies. It is applied to a free–surface model for the North Pacific Ocean.展开更多
The paper has introduced characteristics and study status of new rural construction, illustrated the connotation of leapfrog development of new rural construction, and considered that new rural construction is an impo...The paper has introduced characteristics and study status of new rural construction, illustrated the connotation of leapfrog development of new rural construction, and considered that new rural construction is an important measure to solve "three rural" problems. How to conduct new rural construction in urbanization is a critical issue in social and economic development in China. Based on the favorable condition and development mode of current new rural construction, by taking new rural construction of Haiyang Village in Jiangxia District of Wuhan City for example, it has analyzed the leapfrog development in terms of traditional agriculture, villagers' life quality and rural concept, and the inheritance in terms of culture and rural appearance, so as to give enlightenments to new rural construction in the future.展开更多
Cloud manufacturing is a new manufacturing model with crowd-sourcing characteristics,where a cloud alliance composed of multiple enterprises,completes tasks that a single enterprise cannot accomplish by itself.However...Cloud manufacturing is a new manufacturing model with crowd-sourcing characteristics,where a cloud alliance composed of multiple enterprises,completes tasks that a single enterprise cannot accomplish by itself.However,compared with heterogeneous cloud tasks,there are relatively few studies on cloud alliance formation for homogeneous tasks.To bridge this gap,a novel method is presented in this paper.First,a homogeneous cloud task distribution model under cloud environment was constructed,where services description,selection and combination were modeled.An improved leapfrog algorithm for cloud task distribution(ILA-CTD)was designed to solve the proposed model.Different from the current alternatives,the initialization operator and the leapfrog operator in ILA-CTD can ensure that the algorithm always searches the optimal solution in the feasible space.Finally,the processing of task allocation for 1000 pieces of medical labeling machine bottom plates was studied as a case to show the feasibility of the proposed method.The superiority of ILA-CTD was also proven based on more optimal solutions found,compared with the three other methods.展开更多
The Leapfrog method for the solution of Ordinary Differential Equation initial value problems has been historically popular for several reasons. The method has second order accuracy, requires only one function evaluat...The Leapfrog method for the solution of Ordinary Differential Equation initial value problems has been historically popular for several reasons. The method has second order accuracy, requires only one function evaluation per time step, and is non-dissipative. Despite the mentioned attractive properties, the method has some unfavorable stability properties. The absolute stability region of the method is only an interval located on the imaginary axis, rather than a region in the complex plane. The method is only weakly stable and thus exhibits computational instability in long time integrations over intervals of finite length. In this work, the use of filters is examined for the purposes of both controlling the weak instability and also enlarging the size of the absolute stability region of the method.展开更多
Accurate and efficient integration of the equations of motion is indispensable for molecular dynamics(MD)simulations.Despite the massive use of the conventional leapfrog(LF)integrator in modern computational tools wit...Accurate and efficient integration of the equations of motion is indispensable for molecular dynamics(MD)simulations.Despite the massive use of the conventional leapfrog(LF)integrator in modern computational tools within the framework of MD propagation,further development for better performance is still possible.The alternative version of LF in the middle thermostat scheme(LFmiddle)achieves a higher order of accuracy and efficiency and maintains stable dynamics even with the integration time stepsize extended by several folds.In this work,we perform a benchmark test of the two integrators(LF and LF-middle)in extensive conventional and enhanced sampling simulations,aiming at quantifying the time-stepsizeinduced variations of global properties(e.g.,detailed potential energy terms)as well as of local observables(e.g.,free energy changes or bondlengths)in practical simulations of complex systems.The test set is composed of six chemically and biologically relevant systems,including the conformational change of dihedral flipping in the N-methylacetamide and an AT(AdenineThymine)tract,the intra-molecular proton transfer inside malonaldehyde,the binding free energy calculations of benzene and phenol targeting T4 lysozyme L99A,the hydroxyl bond variations in ethaline deep eutectic solvent,and the potential energy of the blue-light using flavin photoreceptor.It is observed that the time-step-induced error is smaller for the LFmiddle scheme.The outperformance of LF-middle over the conventional LF integrator is much more significant for global properties than local observables.Overall,the current work demonstrates that the LF-middle scheme should be preferably applied to obtain accurate thermodynamics in the simulation of practical chemical and biological systems.展开更多
This paper presents post-layout simulated results of an analog baseband chain for mobile and multimedia applications in a 0.13-μm SiGe BiCMOS process.A programmable 7th-order Chebyshev low pass filter with a calibrat...This paper presents post-layout simulated results of an analog baseband chain for mobile and multimedia applications in a 0.13-μm SiGe BiCMOS process.A programmable 7th-order Chebyshev low pass filter with a calibration circuit is used in the analog baseband chain,and the programmable bandwidth is 1.8/2.5/3/3.5/4 MHz with an attenuation of 26/62 dB at offsets of 1.25/4 MHz.The baseband programmable gain amplifier can achieve a linear 40-dB gain range with 0.5-dB steps.Design trade-offs are carefully considered in designing the baseband circuit,and an automatic calibration circuit is used to achieve the bandwidth accuracy of 2%.A DC offset cancellation loop is also introduced to remove the offset from the layout and self-mixing,and the remaining offset voltage is only 1.87 mV.Implemented in a 0.13-μm SiGe technology with a 0.6-mm2 die size,this baseband achieves IIP3 of 23.16 dBm and dissipates 22.4 mA under a 2.5-V supply.展开更多
Structural rather than cyclical factors are behind the recent China’s growthmoderation. Rather than a fall of final demand, productive capacity is expandingmore slowly. This is accompanied by a rebalancing of the Chi...Structural rather than cyclical factors are behind the recent China’s growthmoderation. Rather than a fall of final demand, productive capacity is expandingmore slowly. This is accompanied by a rebalancing of the Chinese economy,including a shift from investment to consumption, from low-skilled to high-skilledproduction, and from inflows to outflows of FDIs.展开更多
文摘Objective To propose a method to identify the shortest catch-up path by using patent data based on the perspective of technology leapfrogging so as to provide a reference for the catch-up strategy formulation by the governments of the developing countries.Methods Firstly,the international patent classification(IPC)co-occurrence network was used to screen key technologies,and the TOP 5 countries and China were located from the aspects of technology life cycle and technological innovation capabilities.Next,the technology development path based on the ordered clustering algorithm and the main IPC number was set up.Finally,the Dijkstra algorithm was applied to identify the shortest catch-up path.Results and Conclusion Applying this method to the current biopharmaceutical industry with the most potential for development,the shortest catch-up paths are found in the selected C12N15,C07K14 and C12Q1 technology fields,proving the feasibility of the method.
文摘In the 10<sup>th</sup> Five-Year Plan for National Economic and Social Development （2001-05）,the centralauthorities announced that Chinawill adopt a ’leapfrogging’tactic forits technological development. Butthe questions raised by Chinese sci-entists are:How this can
文摘The Chinese Academy of Sci-ences (CAS) has begun introducingthe trial implementation of theKnowledge Innovation Program(KIP)in an all-round manner just as,at the beginning of the new century,the state is about to implement itsTenth Five-Year Plan for thecountry’s ongoing economic andsocial development. This will
文摘The realization of leapfrogging socio-economic development in the Tibet Autonomous Region remains a key issue in the current drive to develop Western China. In this connection, the CAS Academic Divisions have sponsored a task force of a dozen CAS members and nearly 30 other experts to conduct comprehensive studies on the subject, and presented a feasibility study report to the central government. Some of their main ideas are as follows:
文摘Rapid innovation and development of modern technology has brought about the opportunity for developing economies to technological leapfrog. In particular, rather than going through all the learning curve and costly process <span style="font-family:Verdana;">experienced by developed countries, emerging economies instead can tak</span><span style="font-family:Verdana;">e advantage of the opportunities presented by technological shifts. However, inadequate infrastructure is the cause of most challenges that these developing economies presently face. Energy, road, transport and telecommunication networks are the most critical infrastructure needed to drive a sustainable </span><span style="font-family:Verdana;">development and economic growth. As seen in many emerging economies, </span><span style="font-family:Verdana;">small private cars are still dominating the public transport sector, even though </span><span style="font-family:Verdana;">it is evident that they are congesting the poorly managed and crumbling road </span><span style="font-family:Verdana;">infrastructure. Most emerging economies’ cities are currently experiencing rapi</span><span style="font-family:Verdana;">d urbanisation that is leading to massive population explosion. These rapidly growing cities should adopt latest technologies, such as Trackless Trams Systems (TTS). There is no doubt that TTS can probably help in dealing with most of the transport problems experienced in rapidly growing urban areas </span><span style="font-family:Verdana;">within emerging economies. This paper seeks to explore the opportunities</span><span style="font-family:Verdana;"> presented by TTS to bring about the needed technological leapfrogging for the developing countries that are resource constrained to build modern and expensive mass public transport infrastructure. An ideal example of a recent successful technological leapfrog in emerging economies is the low-cost mo</span><span style="font-family:Verdana;">bile phones and increasingly expanding wireless access in urban areas. As </span><span style="font-family:Verdana;">such, countries have been able to eliminate the challenge of building fixed-line t</span><span style="font-family:Verdana;">elecommunications infrastructure, which is capital-intensive. In this study we are undertaking a literature appraisal on technological leapfrogging, and demonstrate how TTS measure up as a potential technology to aid the leap</span><span style="font-family:Verdana;">frogging for the urban transport systems more so in developing countries.</span><span style="font-family:Verdana;"> The study discusses the features, quality, and proficiencies of the new technology. To consider technology for leapfrogging, it ought to be economical enough, less technical, lends itself to partnership, lends itself to community </span><span style="font-family:Verdana;">engagement, allows co-development, and fulfils sustainable development goals (SDGs). The paper is organized into four sections, the introduction, litera</span><span style="font-family:Verdana;">ture appraisal, experiential evidence and debate on Trackless Trams, and </span><span style="font-family:Verdana;">conclu</span><span style="font-family:Verdana;">sion.</span>
基金Hundred Talent Program of Chinese Academy of Sciences under Grant No. 0300YQ000101. Partly supported by the National Natural Sci
文摘Errors due to split time stepping are discussed for an explicit free–surface ocean model. In commonly used split time stepping, the way of time integration for the barotropic momentum equation is not compatible with that of the baroclinic one. The baroclinic equation has three–time–level structure because of leapfrog scheme. The barotropic one, however, has two–time–level structure when represented in terms of the baroclinic time level, on which the baroclinic one is integrated. This incompatibility results in the splitting errors as shown in this paper. The proper split time stepping is therefore proposed in such a way that the compatibility is kept between the barotropic and baroclinic equations. Its splitting errors are shown extremely small, so that it is particularly relevant to long–term integration for climate studies. It is applied to a free–surface model for the North Pacific Ocean.
文摘The paper has introduced characteristics and study status of new rural construction, illustrated the connotation of leapfrog development of new rural construction, and considered that new rural construction is an important measure to solve "three rural" problems. How to conduct new rural construction in urbanization is a critical issue in social and economic development in China. Based on the favorable condition and development mode of current new rural construction, by taking new rural construction of Haiyang Village in Jiangxia District of Wuhan City for example, it has analyzed the leapfrog development in terms of traditional agriculture, villagers' life quality and rural concept, and the inheritance in terms of culture and rural appearance, so as to give enlightenments to new rural construction in the future.
基金The research was financially supported by the National Science and Technology Major Project of China(No.2019ZX04007001)the Science and Technology Major Project of Sichuan Province(No.2020ZDZX0022)。
文摘Cloud manufacturing is a new manufacturing model with crowd-sourcing characteristics,where a cloud alliance composed of multiple enterprises,completes tasks that a single enterprise cannot accomplish by itself.However,compared with heterogeneous cloud tasks,there are relatively few studies on cloud alliance formation for homogeneous tasks.To bridge this gap,a novel method is presented in this paper.First,a homogeneous cloud task distribution model under cloud environment was constructed,where services description,selection and combination were modeled.An improved leapfrog algorithm for cloud task distribution(ILA-CTD)was designed to solve the proposed model.Different from the current alternatives,the initialization operator and the leapfrog operator in ILA-CTD can ensure that the algorithm always searches the optimal solution in the feasible space.Finally,the processing of task allocation for 1000 pieces of medical labeling machine bottom plates was studied as a case to show the feasibility of the proposed method.The superiority of ILA-CTD was also proven based on more optimal solutions found,compared with the three other methods.
文摘The Leapfrog method for the solution of Ordinary Differential Equation initial value problems has been historically popular for several reasons. The method has second order accuracy, requires only one function evaluation per time step, and is non-dissipative. Despite the mentioned attractive properties, the method has some unfavorable stability properties. The absolute stability region of the method is only an interval located on the imaginary axis, rather than a region in the complex plane. The method is only weakly stable and thus exhibits computational instability in long time integrations over intervals of finite length. In this work, the use of filters is examined for the purposes of both controlling the weak instability and also enlarging the size of the absolute stability region of the method.
基金supported by the National Natural Science Foundation of China(No.21961142017)the Ministry of Science and Technology of China(No.2017YFA0204901)。
文摘Accurate and efficient integration of the equations of motion is indispensable for molecular dynamics(MD)simulations.Despite the massive use of the conventional leapfrog(LF)integrator in modern computational tools within the framework of MD propagation,further development for better performance is still possible.The alternative version of LF in the middle thermostat scheme(LFmiddle)achieves a higher order of accuracy and efficiency and maintains stable dynamics even with the integration time stepsize extended by several folds.In this work,we perform a benchmark test of the two integrators(LF and LF-middle)in extensive conventional and enhanced sampling simulations,aiming at quantifying the time-stepsizeinduced variations of global properties(e.g.,detailed potential energy terms)as well as of local observables(e.g.,free energy changes or bondlengths)in practical simulations of complex systems.The test set is composed of six chemically and biologically relevant systems,including the conformational change of dihedral flipping in the N-methylacetamide and an AT(AdenineThymine)tract,the intra-molecular proton transfer inside malonaldehyde,the binding free energy calculations of benzene and phenol targeting T4 lysozyme L99A,the hydroxyl bond variations in ethaline deep eutectic solvent,and the potential energy of the blue-light using flavin photoreceptor.It is observed that the time-step-induced error is smaller for the LFmiddle scheme.The outperformance of LF-middle over the conventional LF integrator is much more significant for global properties than local observables.Overall,the current work demonstrates that the LF-middle scheme should be preferably applied to obtain accurate thermodynamics in the simulation of practical chemical and biological systems.
基金supported by the Inner Mongolia Autonomous Region Open Major Basic Research Project(Grant No.20120905)the National Natural Science Foundation of China(Grant No.51666014)
文摘Wind tunnel experiments of the wake characteristics of a two-blade wind turbine, in the downstream region of 0
基金Project supported by the Provincial and Ministerial Industry-Academia Cooperation Project of China(No.2009A090100019)
文摘This paper presents post-layout simulated results of an analog baseband chain for mobile and multimedia applications in a 0.13-μm SiGe BiCMOS process.A programmable 7th-order Chebyshev low pass filter with a calibration circuit is used in the analog baseband chain,and the programmable bandwidth is 1.8/2.5/3/3.5/4 MHz with an attenuation of 26/62 dB at offsets of 1.25/4 MHz.The baseband programmable gain amplifier can achieve a linear 40-dB gain range with 0.5-dB steps.Design trade-offs are carefully considered in designing the baseband circuit,and an automatic calibration circuit is used to achieve the bandwidth accuracy of 2%.A DC offset cancellation loop is also introduced to remove the offset from the layout and self-mixing,and the remaining offset voltage is only 1.87 mV.Implemented in a 0.13-μm SiGe technology with a 0.6-mm2 die size,this baseband achieves IIP3 of 23.16 dBm and dissipates 22.4 mA under a 2.5-V supply.
文摘Structural rather than cyclical factors are behind the recent China’s growthmoderation. Rather than a fall of final demand, productive capacity is expandingmore slowly. This is accompanied by a rebalancing of the Chinese economy,including a shift from investment to consumption, from low-skilled to high-skilledproduction, and from inflows to outflows of FDIs.
