This paper systematically reviews the institutional evolution of the China-ASEAN Free Trade Area(CAFTA),from its inception in 2002 and full establishment in 2010,through the CAFTA 2.0 upgrade in 2015,to the substantiv...This paper systematically reviews the institutional evolution of the China-ASEAN Free Trade Area(CAFTA),from its inception in 2002 and full establishment in 2010,through the CAFTA 2.0 upgrade in 2015,to the substantive conclusion of CAFTA 3.0 negotiations in 2024.It highlights the key institutional innovations along this trajectory and examines the structural complementarities between China and ASEAN in terms of clean energy resources and industrial capabilities.Based on this foundation,the paper develops a“policy-technology-capital”analytical framework to explain the transition of regional clean energy cooperation from initial resource-industry complementarity toward deeper institution-market integration.Guided by this framework,the study proposes a roadmap and concrete policy recommendations for regional cooperation through 2030.These include:aligning regional emissions targets and renewable energy share goals;establishing a mutual recognition system for green standards;building a digitalized green supply chain and carbon traceability platform;designing cross-border green finance corridors;and constructing integrated electricity-hydrogen-storage corridors in synergy with the Belt and Road Initiative.The study concludes that,if effectively implemented,these measures could raise the regional share of renewable electricity generation to over 30%by 2030.China and ASEAN would then be well positioned to lead in forming a low-carbon,interconnected,and shared regional energy community,offering a replicable and scalable model for low-carbon transition across the Global South.展开更多
Images with complementary spectral information can be recorded using image sensors that can identify visible and near-infrared spectrum.The fusion of visible and nearinfrared(NIR)aims to enhance the quality of images ...Images with complementary spectral information can be recorded using image sensors that can identify visible and near-infrared spectrum.The fusion of visible and nearinfrared(NIR)aims to enhance the quality of images acquired by video monitoring systems for the ease of user observation and data processing.Unfortunately,current fusion algorithms produce artefacts and colour distortion since they cannot make use of spectrum properties and are lacking in information complementarity.Therefore,an information complementarity fusion(ICF)model is designed based on physical signals.In order to separate high-frequency noise from important information in distinct frequency layers,the authors first extracted texture-scale and edge-scale layers using a two-scale filter.Second,the difference map between visible and near-infrared was filtered using the extended-DoG filter to produce the initial visible-NIR complementary weight map.Then,to generate a guide map,the near-infrared image with night adjustment was processed as well.The final complementarity weight map was subsequently derived via an arctanI function mapping using the guide map and the initial weight maps.Finally,fusion images were generated with the complementarity weight maps.The experimental results demonstrate that the proposed approach outperforms the state-of-the-art in both avoiding artificial colours as well as effectively utilising information complementarity.展开更多
A family of neural networks is proposed to solve linear complementarity problems(LCP).The neural networks are constructed from the novel equivalent model of LCP,which is reformulated by utilizing the modulus and smoot...A family of neural networks is proposed to solve linear complementarity problems(LCP).The neural networks are constructed from the novel equivalent model of LCP,which is reformulated by utilizing the modulus and smoothing technologies.Some important properties of the proposed novel equivalent model are summarized.In addition,the stability properties of the proposed steepest descent-based neural networks for LCP are analyzed.In order to illustrate the theoretical results,we provide some numerical simulations and compare the proposed neural networks with existing neural networks based on the NCP-functions.Numerical results indicate that the performance of the proposed neural networks is effective and robust.展开更多
Shortly after the collapse of the USSR,in The End of History and the Last Man(1992),Francis Fukuyama encircled a spiritual condition pointing“toward establishing capitalist liberal democracies as the end state of the...Shortly after the collapse of the USSR,in The End of History and the Last Man(1992),Francis Fukuyama encircled a spiritual condition pointing“toward establishing capitalist liberal democracies as the end state of the historical process”,while leaving the possibility open for a fall back“into the chaos and bloodshed of history”.In Historien er ikke slut(History has not ended,2000),Thomas Thurah,a Dane,converses with 36 European writers,most of whom implicitly dispute Fukuyama’s notion of an uplifting end of history.Rather,the common denominator for many of these interlocutors is their emphasis on“the contradiction-filled state of mind being an important part of the historical,social and creative processes that form both us and our world”(p.454).Thurah concludes that“the contradictory,the paradoxical,the incommensurable or the unstable truths…are characteristics of this reality,which every work of art seeks to give expression”.I investigate 2/3 of these interviews and lay bare their notions of Europe around 2000 and how the interviewees envision their continent’s legacy as informed by a variety of ruptures,some of which they predict will prevail.Simultaneously,I reflect on the conditions of possibility that underlie the authorial discourses and determine their outcomes.展开更多
In this paper,we propose a new full-Newton step feasible interior-point algorithm for the special weighted linear complementarity problems.The proposed algorithm employs the technique of algebraic equivalent transform...In this paper,we propose a new full-Newton step feasible interior-point algorithm for the special weighted linear complementarity problems.The proposed algorithm employs the technique of algebraic equivalent transformation to derive the search direction.It is shown that the proximity measure reduces quadratically at each iteration.Moreover,the iteration bound of the algorithm is as good as the best-known polynomial complexity for these types of problems.Furthermore,numerical results are presented to show the efficiency of the proposed algorithm.展开更多
The year 2025 marks the 50th anniversary of the establishment of diplomatic relations between China and Thailand,as well as the“Golden Jubilee of Sino-Thai Friendship”.Over the past half-century,the scale and scope ...The year 2025 marks the 50th anniversary of the establishment of diplomatic relations between China and Thailand,as well as the“Golden Jubilee of Sino-Thai Friendship”.Over the past half-century,the scale and scope of economic and trade cooperation between China and Thailand have dramatically expanded.Both nations have strengthened their bilateral economic ties,which have increasingly strengthened their interdependence and.complementarity,presenting a broad prospect of mutual benefit and win-win cooperation.展开更多
This paper presents a new capacity planning method that utilizes the complementary characteristics of wind and solar power output.It addresses the limitations of relying on a single metric for a comprehensive assessme...This paper presents a new capacity planning method that utilizes the complementary characteristics of wind and solar power output.It addresses the limitations of relying on a single metric for a comprehensive assessment of complementarity.To enable more accurate predictions of the optimal wind-solar ratio,a comprehensive complementarity rate is proposed,which allows for the optimization of wind-solar capacity based on this measure.Initially,the Clayton Copula function is employed to create a joint probability distribution model for wind and solar power,enabling the calculation of the comprehensive complementarity rate.Following this,a joint planning model is developed to enhance the system’s economy and reliability.The goal is to minimize total costs,load deficit rates,and curtailment rates by applying an ImprovedMulti-Objective Particle SwarmOptimization algorithm(IMOPSO).Results show that when the proportion of wind power reaches 70%,the comprehensive complementarity rate is optimized.This optimization leads to a 14.83%reduction in total costs and a 9.27%decrease in curtailment rates.Compared to existing studies,this paper offers a multidimensional analysis of the relationship between the comprehensive complementarity rate and the optimal wind-solar ratio,thereby improving predictive accuracy and providing a valuable reference for research on the correlation between wind and solar power.展开更多
China and ASEAN are natural partners and close neighbors linked by both land and sea.We share deep cultural ties and enjoy strong economic complementarity,forming a community with a shared future.For 16 consecutive ye...China and ASEAN are natural partners and close neighbors linked by both land and sea.We share deep cultural ties and enjoy strong economic complementarity,forming a community with a shared future.For 16 consecutive years,China has been ASEAN’s largest trading partner,while ASEAN has remained China’s largest trading partner for the past five.Our cooperation has become an increasingly important driver of global growth.With the full implementation of the Regional Comprehensive Economic Partnership(RCEP),China-ASEAN relations have entered a new stage of all-around,wide-ranging,and multi-level development.展开更多
In this paper,a fu-Newton step interior-point algorithm is proposed for solving P_(*)(k)-linear complementarity problem based on a new search direction,which is an extension of Grimes'algorithm.It is proved that t...In this paper,a fu-Newton step interior-point algorithm is proposed for solving P_(*)(k)-linear complementarity problem based on a new search direction,which is an extension of Grimes'algorithm.It is proved that the number of iterations of the algorithm is O(n^(1/2)(1+4κ)logn/ε),which matches the best known iteration bound of the interior-point method for P_(*)(k)-linear complementarity problem.Some numerical results have proved the feasibility and efficiency of the proposed algorithm.展开更多
The Asia-Pacific region is the most dynamic part of the global economy.After over 50 years of continuously expanding trade,investment and industrial cooperation,the region has formed a highly-tied multi-level labor di...The Asia-Pacific region is the most dynamic part of the global economy.After over 50 years of continuously expanding trade,investment and industrial cooperation,the region has formed a highly-tied multi-level labor division system covering vertical integration and horizontal complementarity of industrial chains.From the V-shaped development model in the twentieth century to the East Asian production network in the twenty-first century,the intra-industry and intra-product division of labor in the Asia-Pacific region has been ever deepening.However,due to the region’s high dependence on the U.S.market,the division of labor model in the Asia-Pacific suffers structural problems and is relatively fragile.Under the shock of Trump 1.0,countries in the Asia-Pacific region were forced to make adaptive adjustments,causing short-term turmoil in the regional economic order.Trump’s strong return in 2025,driven by the“America First”principle,brought forth a series of policies with strong unilateralism,isolationism and protectionism tendencies within just a few months。展开更多
In traditional urban geography, city contact research is a classic study element in city research. In general, researchers use the traditional gravity model to characterize the contacts that exist between two cities. ...In traditional urban geography, city contact research is a classic study element in city research. In general, researchers use the traditional gravity model to characterize the contacts that exist between two cities. The traditional gravity model assumes ideal conditions, but these preconditions and their results often do not exist in realistic conditions. Thus, we used a modified gravity model to characterize the city contacts within a specific region. This model considers factors such as intercity complementarities, government intervention, and the diversity of the transportation infrastructure which is characterized as the transportation distance instead of the traditional Euclidean distance. We applied this model to an empirical study of city contact in the Zhujiang(Pearl) River Delta(PRD) of China. The regression results indicated that the modified gravity model could measure city contact more accurately and comprehensively than the traditional gravity model, i.e., it yielded a higher adjusted R2 value(0.379) than the traditional gravity model result(0.259). Our study also suggests that, in addition to urban-regional and metropolitan development, the complementarities of the basic functions of cities at the administrative and market levels, as well as the corporeal and immaterial levels, play very significant roles in the characterization of city contact. Given the complexity of city contact, it will be necessary to consider more relevant influential factors in the modified gravity model to characterize the features of city contact in the future.展开更多
The literature suggests that protection of knowledge from the threat for opportunism is a primary mover for the choice of entry mode.However,the knowledge construct is oversimplified in the literature on entry mode.Th...The literature suggests that protection of knowledge from the threat for opportunism is a primary mover for the choice of entry mode.However,the knowledge construct is oversimplified in the literature on entry mode.The combination of different types of knowledge held by a firm reduces the risk of misappropriation and the threat of opportunism is often unimportant in entry mode decisions.Based on these discussions,a new conceptual knowledgebased model of entry mode choice is devoloped.In this model,the knowledge is classified into business knowledge and location knowledge,the strategies into exploitation and exploration.This model focuses on two main attributes of knowledge,namely,embedded ness and complementarity.It is suggested that embedded ness and complementarity of business knowledge and location knowledge affect the entry mode choice.The knowledge strategies moderate the relationships between the attributes of knowledge and entry mode.Transferring capacity is also introduced in this model.展开更多
Based on the research and exploration of lithostratigraphic reservoir in the Jizhong depression of the Bohai Bay basin and Erlian basin, the hydrocarbon distribution in a continental oil-rich sag has "complementa...Based on the research and exploration of lithostratigraphic reservoir in the Jizhong depression of the Bohai Bay basin and Erlian basin, the hydrocarbon distribution in a continental oil-rich sag has "complementarity" feature, viz. the hydrocarbon resources configuration and plane distribution of the structural reservoir and lithostratigraphic reservoir have the "complementarity". This distribution feature is controlled by many factors such as the macroscopical geological setting, reservoir-forming condition, and the reservoir-forming mechanism of structural reservoir and lithostratigraphic reservoir. More research shows that the "complementarity" of hydrocarbon distribution is prevalent in every kind of continental basin. This "rule" helps to establish a new exploration theory, a scientific exploration program, and make proper exploration deployments in hydrocarbon exploration. Therefore, it is significant for the exploration work in continental petroliferous basins of China.展开更多
The main purpose of this paper is to present a linear complementarity problem （LCP） method for a planar passive dynamic walker with round feet based on an event-driven scheme. The passive dynamic walker is treated a...The main purpose of this paper is to present a linear complementarity problem （LCP） method for a planar passive dynamic walker with round feet based on an event-driven scheme. The passive dynamic walker is treated as a planar multi-rigid-body system. The dynamic equations of the passive dynamic walker are obtained by using Lagrange＇s equations of the second kind. The normal forces and frictional forces acting on the feet of the passive walker are described based on a modified Hertz contact model and Coulomb＇s law of dry friction. The state transition problem of stick-slip between feet and floor is formulated as an LCR which is solved with an event-driven scheme. Finally, to validate the methodology, four gaits of the walker are simulated： the stance leg neither slips nor bounces; the stance leg slips without bouncing; the stance leg bounces without slipping; the walker stands after walking several steps.展开更多
Background: Forest productivity has a pivotal role in human well-being. Vegetation quantity, niche complementarity, mass-ratio, and soil resources are alternative/complementary ecological mechanisms driving productivi...Background: Forest productivity has a pivotal role in human well-being. Vegetation quantity, niche complementarity, mass-ratio, and soil resources are alternative/complementary ecological mechanisms driving productivity. One challenge in current forest management depends on identifying and manipulating these mechanisms to enhance productivity. This study assessed the extent to which these mechanisms control aboveground biomass productivity(AGBP) of a Chilean mediterranean-type matorral. AGBP measured as tree aboveground biomass changes over a 7-years period, was estimated for twelve 25 m × 25 m plots across a wide range of matorral compositions and structures. Variables related to canopy structure, species and functional diversity, species and functional dominance, soil texture, soil water and soil nitrogen content were measured as surrogates of the four mechanisms proposed. Linear regression models were used to test the hypotheses. A multimodel inference based on the Akaike’s information criterion was used to select the best models explaining AGBP and for identifying the relative importance of each mechanism.Results: Vegetation quantity(tree density) and mass-ratio(relative biomass of Cryptocarya alba, a conservative species) were the strongest drivers increasing AGBP, while niche complementarity(richness species) and soil resources(sand, %) had a smaller effect either decreasing or increasing AGBP, respectively. This study provides the first assessment of alternative mechanisms driving AGBP in mediterranean forests of Chile. There is strong evidence suggesting that the vegetation quantity and mass-ratio mechanisms are key drivers of AGBP, such as in other tropical and temperate forests. However, in contrast with other studies from mediterranean-type forests, our results show a negative effect of species diversity and a small effect of soil resources on AGBP.Conclusion: AGBP in the Chilean matorral depends mainly on the vegetation quantity and mass-ratio mechanisms.The findings of this study have implications for matorral restoration and management for the production of timber and non-timber products and carbon sequestration.展开更多
Under suitable conditions,the monotone convergence about the projected iteration method for solving linear complementarity problem is proved and the influence of the involved parameter matrix on the convergence rate o...Under suitable conditions,the monotone convergence about the projected iteration method for solving linear complementarity problem is proved and the influence of the involved parameter matrix on the convergence rate of this method is investigated.展开更多
In this paper, a QP-free feasible method with piecewise NCP functions is proposed for nonlinear inequality constrained optimization problems. The new NCP functions are piecewise linear-rational, regular pseudo-smooth...In this paper, a QP-free feasible method with piecewise NCP functions is proposed for nonlinear inequality constrained optimization problems. The new NCP functions are piecewise linear-rational, regular pseudo-smooth and have nice properties. This method is based on the solutions of linear systems of equation reformulation of KKT optimality conditions, by using the piecewise NCP functions. This method is implementable and globally convergent without assuming the strict complementarity condition, the isolatedness of accumulation points. Purr thermore, the gradients of active constraints are not requested to be linearly independent. The submatrix which may be obtained by quasi-Newton methods, is not requested to be uniformly positive definite. Preliminary numerical results indicate that this new QP-free method is quite promising.展开更多
文摘This paper systematically reviews the institutional evolution of the China-ASEAN Free Trade Area(CAFTA),from its inception in 2002 and full establishment in 2010,through the CAFTA 2.0 upgrade in 2015,to the substantive conclusion of CAFTA 3.0 negotiations in 2024.It highlights the key institutional innovations along this trajectory and examines the structural complementarities between China and ASEAN in terms of clean energy resources and industrial capabilities.Based on this foundation,the paper develops a“policy-technology-capital”analytical framework to explain the transition of regional clean energy cooperation from initial resource-industry complementarity toward deeper institution-market integration.Guided by this framework,the study proposes a roadmap and concrete policy recommendations for regional cooperation through 2030.These include:aligning regional emissions targets and renewable energy share goals;establishing a mutual recognition system for green standards;building a digitalized green supply chain and carbon traceability platform;designing cross-border green finance corridors;and constructing integrated electricity-hydrogen-storage corridors in synergy with the Belt and Road Initiative.The study concludes that,if effectively implemented,these measures could raise the regional share of renewable electricity generation to over 30%by 2030.China and ASEAN would then be well positioned to lead in forming a low-carbon,interconnected,and shared regional energy community,offering a replicable and scalable model for low-carbon transition across the Global South.
基金supports in part by the Natural Science Foundation of China(NSFC)under contract No.62171253the Young Elite Scientists Sponsorship Program by CAST under program No.2022QNRC001,as well as the Fundamental Research Funds for the Central Universities.
文摘Images with complementary spectral information can be recorded using image sensors that can identify visible and near-infrared spectrum.The fusion of visible and nearinfrared(NIR)aims to enhance the quality of images acquired by video monitoring systems for the ease of user observation and data processing.Unfortunately,current fusion algorithms produce artefacts and colour distortion since they cannot make use of spectrum properties and are lacking in information complementarity.Therefore,an information complementarity fusion(ICF)model is designed based on physical signals.In order to separate high-frequency noise from important information in distinct frequency layers,the authors first extracted texture-scale and edge-scale layers using a two-scale filter.Second,the difference map between visible and near-infrared was filtered using the extended-DoG filter to produce the initial visible-NIR complementary weight map.Then,to generate a guide map,the near-infrared image with night adjustment was processed as well.The final complementarity weight map was subsequently derived via an arctanI function mapping using the guide map and the initial weight maps.Finally,fusion images were generated with the complementarity weight maps.The experimental results demonstrate that the proposed approach outperforms the state-of-the-art in both avoiding artificial colours as well as effectively utilising information complementarity.
基金Supported by the National Natural Science Foundation of China(12371378,41725017,11901098).
文摘A family of neural networks is proposed to solve linear complementarity problems(LCP).The neural networks are constructed from the novel equivalent model of LCP,which is reformulated by utilizing the modulus and smoothing technologies.Some important properties of the proposed novel equivalent model are summarized.In addition,the stability properties of the proposed steepest descent-based neural networks for LCP are analyzed.In order to illustrate the theoretical results,we provide some numerical simulations and compare the proposed neural networks with existing neural networks based on the NCP-functions.Numerical results indicate that the performance of the proposed neural networks is effective and robust.
文摘Shortly after the collapse of the USSR,in The End of History and the Last Man(1992),Francis Fukuyama encircled a spiritual condition pointing“toward establishing capitalist liberal democracies as the end state of the historical process”,while leaving the possibility open for a fall back“into the chaos and bloodshed of history”.In Historien er ikke slut(History has not ended,2000),Thomas Thurah,a Dane,converses with 36 European writers,most of whom implicitly dispute Fukuyama’s notion of an uplifting end of history.Rather,the common denominator for many of these interlocutors is their emphasis on“the contradiction-filled state of mind being an important part of the historical,social and creative processes that form both us and our world”(p.454).Thurah concludes that“the contradictory,the paradoxical,the incommensurable or the unstable truths…are characteristics of this reality,which every work of art seeks to give expression”.I investigate 2/3 of these interviews and lay bare their notions of Europe around 2000 and how the interviewees envision their continent’s legacy as informed by a variety of ruptures,some of which they predict will prevail.Simultaneously,I reflect on the conditions of possibility that underlie the authorial discourses and determine their outcomes.
基金Supported by the Optimisation Theory and Algorithm Research Team(Grant No.23kytdzd004)University Science Research Project of Anhui Province(Grant No.2024AH050631)the General Programs for Young Teacher Cultivation of Educational Commission of Anhui Province(Grant No.YQYB2023090).
文摘In this paper,we propose a new full-Newton step feasible interior-point algorithm for the special weighted linear complementarity problems.The proposed algorithm employs the technique of algebraic equivalent transformation to derive the search direction.It is shown that the proximity measure reduces quadratically at each iteration.Moreover,the iteration bound of the algorithm is as good as the best-known polynomial complexity for these types of problems.Furthermore,numerical results are presented to show the efficiency of the proposed algorithm.
文摘The year 2025 marks the 50th anniversary of the establishment of diplomatic relations between China and Thailand,as well as the“Golden Jubilee of Sino-Thai Friendship”.Over the past half-century,the scale and scope of economic and trade cooperation between China and Thailand have dramatically expanded.Both nations have strengthened their bilateral economic ties,which have increasingly strengthened their interdependence and.complementarity,presenting a broad prospect of mutual benefit and win-win cooperation.
基金This work was supported by Inner Mongolia Natural Science Foundation Project and the Optimization of Exergy Efficiency of a Hybrid Energy Storage System with Crossover Control for Wind Power(2023JQ04).
文摘This paper presents a new capacity planning method that utilizes the complementary characteristics of wind and solar power output.It addresses the limitations of relying on a single metric for a comprehensive assessment of complementarity.To enable more accurate predictions of the optimal wind-solar ratio,a comprehensive complementarity rate is proposed,which allows for the optimization of wind-solar capacity based on this measure.Initially,the Clayton Copula function is employed to create a joint probability distribution model for wind and solar power,enabling the calculation of the comprehensive complementarity rate.Following this,a joint planning model is developed to enhance the system’s economy and reliability.The goal is to minimize total costs,load deficit rates,and curtailment rates by applying an ImprovedMulti-Objective Particle SwarmOptimization algorithm(IMOPSO).Results show that when the proportion of wind power reaches 70%,the comprehensive complementarity rate is optimized.This optimization leads to a 14.83%reduction in total costs and a 9.27%decrease in curtailment rates.Compared to existing studies,this paper offers a multidimensional analysis of the relationship between the comprehensive complementarity rate and the optimal wind-solar ratio,thereby improving predictive accuracy and providing a valuable reference for research on the correlation between wind and solar power.
文摘China and ASEAN are natural partners and close neighbors linked by both land and sea.We share deep cultural ties and enjoy strong economic complementarity,forming a community with a shared future.For 16 consecutive years,China has been ASEAN’s largest trading partner,while ASEAN has remained China’s largest trading partner for the past five.Our cooperation has become an increasingly important driver of global growth.With the full implementation of the Regional Comprehensive Economic Partnership(RCEP),China-ASEAN relations have entered a new stage of all-around,wide-ranging,and multi-level development.
基金Supported by the Optimization Theory and Algorithm Research Team(23kytdzd004)the General Programs for Young Teacher Cultivation of Educational Commission of Anhui Province of China(YQYB2023090)the University Science Research Project of Anhui Province(2024AH050631)。
文摘In this paper,a fu-Newton step interior-point algorithm is proposed for solving P_(*)(k)-linear complementarity problem based on a new search direction,which is an extension of Grimes'algorithm.It is proved that the number of iterations of the algorithm is O(n^(1/2)(1+4κ)logn/ε),which matches the best known iteration bound of the interior-point method for P_(*)(k)-linear complementarity problem.Some numerical results have proved the feasibility and efficiency of the proposed algorithm.
文摘The Asia-Pacific region is the most dynamic part of the global economy.After over 50 years of continuously expanding trade,investment and industrial cooperation,the region has formed a highly-tied multi-level labor division system covering vertical integration and horizontal complementarity of industrial chains.From the V-shaped development model in the twentieth century to the East Asian production network in the twenty-first century,the intra-industry and intra-product division of labor in the Asia-Pacific region has been ever deepening.However,due to the region’s high dependence on the U.S.market,the division of labor model in the Asia-Pacific suffers structural problems and is relatively fragile.Under the shock of Trump 1.0,countries in the Asia-Pacific region were forced to make adaptive adjustments,causing short-term turmoil in the regional economic order.Trump’s strong return in 2025,driven by the“America First”principle,brought forth a series of policies with strong unilateralism,isolationism and protectionism tendencies within just a few months。
基金Under the auspices of National Natural Science Foundation of China(No.41271177)Guangdong Natural Science Foundation(No.S2012010008902)
文摘In traditional urban geography, city contact research is a classic study element in city research. In general, researchers use the traditional gravity model to characterize the contacts that exist between two cities. The traditional gravity model assumes ideal conditions, but these preconditions and their results often do not exist in realistic conditions. Thus, we used a modified gravity model to characterize the city contacts within a specific region. This model considers factors such as intercity complementarities, government intervention, and the diversity of the transportation infrastructure which is characterized as the transportation distance instead of the traditional Euclidean distance. We applied this model to an empirical study of city contact in the Zhujiang(Pearl) River Delta(PRD) of China. The regression results indicated that the modified gravity model could measure city contact more accurately and comprehensively than the traditional gravity model, i.e., it yielded a higher adjusted R2 value(0.379) than the traditional gravity model result(0.259). Our study also suggests that, in addition to urban-regional and metropolitan development, the complementarities of the basic functions of cities at the administrative and market levels, as well as the corporeal and immaterial levels, play very significant roles in the characterization of city contact. Given the complexity of city contact, it will be necessary to consider more relevant influential factors in the modified gravity model to characterize the features of city contact in the future.
文摘The literature suggests that protection of knowledge from the threat for opportunism is a primary mover for the choice of entry mode.However,the knowledge construct is oversimplified in the literature on entry mode.The combination of different types of knowledge held by a firm reduces the risk of misappropriation and the threat of opportunism is often unimportant in entry mode decisions.Based on these discussions,a new conceptual knowledgebased model of entry mode choice is devoloped.In this model,the knowledge is classified into business knowledge and location knowledge,the strategies into exploitation and exploration.This model focuses on two main attributes of knowledge,namely,embedded ness and complementarity.It is suggested that embedded ness and complementarity of business knowledge and location knowledge affect the entry mode choice.The knowledge strategies moderate the relationships between the attributes of knowledge and entry mode.Transferring capacity is also introduced in this model.
文摘Based on the research and exploration of lithostratigraphic reservoir in the Jizhong depression of the Bohai Bay basin and Erlian basin, the hydrocarbon distribution in a continental oil-rich sag has "complementarity" feature, viz. the hydrocarbon resources configuration and plane distribution of the structural reservoir and lithostratigraphic reservoir have the "complementarity". This distribution feature is controlled by many factors such as the macroscopical geological setting, reservoir-forming condition, and the reservoir-forming mechanism of structural reservoir and lithostratigraphic reservoir. More research shows that the "complementarity" of hydrocarbon distribution is prevalent in every kind of continental basin. This "rule" helps to establish a new exploration theory, a scientific exploration program, and make proper exploration deployments in hydrocarbon exploration. Therefore, it is significant for the exploration work in continental petroliferous basins of China.
基金supported by the National Natural Science Foundation of China (Grants 11372018, 11772021)
文摘The main purpose of this paper is to present a linear complementarity problem （LCP） method for a planar passive dynamic walker with round feet based on an event-driven scheme. The passive dynamic walker is treated as a planar multi-rigid-body system. The dynamic equations of the passive dynamic walker are obtained by using Lagrange＇s equations of the second kind. The normal forces and frictional forces acting on the feet of the passive walker are described based on a modified Hertz contact model and Coulomb＇s law of dry friction. The state transition problem of stick-slip between feet and floor is formulated as an LCR which is solved with an event-driven scheme. Finally, to validate the methodology, four gaits of the walker are simulated： the stance leg neither slips nor bounces; the stance leg slips without bouncing; the stance leg bounces without slipping; the walker stands after walking several steps.
基金Funding for this research was obtained from CONICy T(Comisión Nacional de Investigación Científica y Tecnológica)for the grant Fondecyt No1150877funding was derived from the CONICy T doctoral grant No 21150802
文摘Background: Forest productivity has a pivotal role in human well-being. Vegetation quantity, niche complementarity, mass-ratio, and soil resources are alternative/complementary ecological mechanisms driving productivity. One challenge in current forest management depends on identifying and manipulating these mechanisms to enhance productivity. This study assessed the extent to which these mechanisms control aboveground biomass productivity(AGBP) of a Chilean mediterranean-type matorral. AGBP measured as tree aboveground biomass changes over a 7-years period, was estimated for twelve 25 m × 25 m plots across a wide range of matorral compositions and structures. Variables related to canopy structure, species and functional diversity, species and functional dominance, soil texture, soil water and soil nitrogen content were measured as surrogates of the four mechanisms proposed. Linear regression models were used to test the hypotheses. A multimodel inference based on the Akaike’s information criterion was used to select the best models explaining AGBP and for identifying the relative importance of each mechanism.Results: Vegetation quantity(tree density) and mass-ratio(relative biomass of Cryptocarya alba, a conservative species) were the strongest drivers increasing AGBP, while niche complementarity(richness species) and soil resources(sand, %) had a smaller effect either decreasing or increasing AGBP, respectively. This study provides the first assessment of alternative mechanisms driving AGBP in mediterranean forests of Chile. There is strong evidence suggesting that the vegetation quantity and mass-ratio mechanisms are key drivers of AGBP, such as in other tropical and temperate forests. However, in contrast with other studies from mediterranean-type forests, our results show a negative effect of species diversity and a small effect of soil resources on AGBP.Conclusion: AGBP in the Chilean matorral depends mainly on the vegetation quantity and mass-ratio mechanisms.The findings of this study have implications for matorral restoration and management for the production of timber and non-timber products and carbon sequestration.
文摘Under suitable conditions,the monotone convergence about the projected iteration method for solving linear complementarity problem is proved and the influence of the involved parameter matrix on the convergence rate of this method is investigated.
基金supported by the Natural science Foundation of China(10371089,10571137)
文摘In this paper, a QP-free feasible method with piecewise NCP functions is proposed for nonlinear inequality constrained optimization problems. The new NCP functions are piecewise linear-rational, regular pseudo-smooth and have nice properties. This method is based on the solutions of linear systems of equation reformulation of KKT optimality conditions, by using the piecewise NCP functions. This method is implementable and globally convergent without assuming the strict complementarity condition, the isolatedness of accumulation points. Purr thermore, the gradients of active constraints are not requested to be linearly independent. The submatrix which may be obtained by quasi-Newton methods, is not requested to be uniformly positive definite. Preliminary numerical results indicate that this new QP-free method is quite promising.
