For non-stationary complex dynamic systems,a standardized algorithm is developed to compute time correlation functions,addressing the limitations of traditional methods reliant on the stationary assumption.The propose...For non-stationary complex dynamic systems,a standardized algorithm is developed to compute time correlation functions,addressing the limitations of traditional methods reliant on the stationary assumption.The proposed algorithm integrates two-point and multi-point time correlation functions into a unified framework.Further,it is verified by a practical application in complex financial systems,demonstrating its potential in various complex dynamic systems.展开更多
This paper describes how scientist-philosopher Charles S. Peirce （1839-1914） develops theories that lead eventually to contemporary complex/dynamic systems. In both Peirce and complexity theory, possible bridges app...This paper describes how scientist-philosopher Charles S. Peirce （1839-1914） develops theories that lead eventually to contemporary complex/dynamic systems. In both Peirce and complexity theory, possible bridges appear between analogical/reductionist representations and metaphorical/creative symbols. In complex/dynamic terms, Peirce＇s scientific theories become a conceptual egg that hatches a century later in complex systems, which is relevant in turn to environmental science and engineering.展开更多
This study employs a Q methodology to explore the developmental routines of oral English ability for 12 English major students in China inspired by Complex and Dynamic Systems Theory(CDST).The data analysis suggests t...This study employs a Q methodology to explore the developmental routines of oral English ability for 12 English major students in China inspired by Complex and Dynamic Systems Theory(CDST).The data analysis suggests the next findings:(1)two developmental patterns emerge as the gradual improvement and the strong phase shift influenced by internal and external factors for interactions among different subsystems;(2)guided by CDST,the study proves the importance of self-organization and initial condition in previous studies.According to the above findings,It is highly suggested for teachers to form a holistic view of students’oral English development concerning the non-linear characteristic and individual differences.展开更多
Traditional biomechanical analyses of human movement are generally derived from linear mathematics.While these methods can be useful in many situations,they do not describe behaviors in human systems that are predomin...Traditional biomechanical analyses of human movement are generally derived from linear mathematics.While these methods can be useful in many situations,they do not describe behaviors in human systems that are predominately nonlinear.For this reason,nonlinear analysis methods based on a dynamical systems approach have become more prevalent in recent literature.These analysis techniques have provided new insights into how systems(1) maintain pattern stability,(2) transition into new states,and(3) are governed by short-and long-term(fractal) correlational processes at different spatio-temporal scales.These different aspects of system dynamics are typically investigated using concepts related to variability,stability,complexity,and adaptability.The purpose of this paper is to compare and contrast these different concepts and demonstrate that,although related,these terms represent fundamentally different aspects of system dynamics.In particular,we argue that variability should not uniformly be equated with stability or complexity of movement.In addition,current dynamic stability measures based on nonlinear analysis methods(such as the finite maximal Lyapunov exponent) can reveal local instabilities in movement dynamics,but the degree to which these local instabilities relate to global postural and gait stability and the ability to resist external perturbations remains to be explored.Finally,systematic studies are needed to relate observed reductions in complexity with aging and disease to the adaptive capabilities of the movement system and how complexity changes as a function of different task constraints.展开更多
Parameter identification is a key requirement in the field of automated control of unmanned excavators （UEs）. Furthermore, the UE operates in unstructured, often hazardous environments, and requires a robust paramet...Parameter identification is a key requirement in the field of automated control of unmanned excavators （UEs）. Furthermore, the UE operates in unstructured, often hazardous environments, and requires a robust parameter identification scheme for field applications. This paper presents the results of a research study on parameter identification for UE. Three identification methods, the Newton-Raphson method, the generalized Newton method, and the least squares method are used and compared for prediction accuracy, robustness to noise and computational speed. The techniques are used to identify the link parameters （mass, inertia, and length） and friction coefficients of the full-scale UE. Using experimental data from a full-scale field UE, the values of link parameters and the friction coefficient are identified. Some of the identified parameters are compared with measured physical values. Furthermore, the joint torques and positions computed by the proposed model using the identified parameters are validated against measured data. The comparison shows that both the Newton-Raphson method and the generalized Newton method are better in terms of prediction accuracy. The Newton-Raphson method is computationally efficient and has potential for real time application, but the generalized Newton method is slightly more robust to measurement noise. The experimental data were obtained in collaboration with QinetiQ Ltd.展开更多
Let Δυ be the unit ball in ?υ with center 0 (the origin of υ) and let F:Δυ→?υbe a holomorphic map withF(0) = 0. This paper is to study the fixed point multiplicities at the origin 0 of the iteratesF i =F°...Let Δυ be the unit ball in ?υ with center 0 (the origin of υ) and let F:Δυ→?υbe a holomorphic map withF(0) = 0. This paper is to study the fixed point multiplicities at the origin 0 of the iteratesF i =F°?°F (i times),i = 1,2,.... This problem is easy when υ = 1, but it is very complicated when υ > 1. We will study this problem generally.展开更多
The current global attempts to control the so-called“Neglected Tropical Diseases(NTDs)”have the potential to significantly reduce the morbidity suffered by some of the world’s poorest communities.However,the govern...The current global attempts to control the so-called“Neglected Tropical Diseases(NTDs)”have the potential to significantly reduce the morbidity suffered by some of the world’s poorest communities.However,the governance of these control programmes is driven by a managerial rationality that assumes predictability of proposed interventions,and which thus primarily seeks to improve the cost-effectiveness of implementation by measuring performance in terms of pre-determined outputs.Here,we argue that this approach has reinforced the narrow normal-science model for controlling parasitic diseases,and in doing so fails to address the complex dynamics,uncertainty and socio-ecological context-specificity that invariably underlie parasite transmission.We suggest that a new governance approach is required that draws on a combination of non-equilibrium thinking about the operation of complex,adaptive,systems from the natural sciences and constructivist social science perspectives that view the accumulation of scientific knowledge as contingent on historical interests and norms,if more effective control approaches sufficiently sensitive to local disease contexts are to be devised,applied and managed.At the core of this approach is an emphasis on the need for a process that assists with the inclusion of diverse perspectives,social learning and deliberation,and a reflexive approach to addressing system complexity and incertitude,while balancing this flexibility with stability-focused structures.We derive and discuss a possible governance framework and outline an organizational structure that could be used to effectively deal with the complexity of accomplishing global NTD control.We also point to examples of complexity-based management structures that have been used in parasite control previously,which could serve as practical templates for developing similar governance structures to better manage global NTD control.Our results hold important wider implications for global health policy aiming to effectively control and eradicate parasitic diseases across the world.展开更多
This article traces the evolution of the field of second language acquisition/development(SLA/SLD). It chronicles the evolution in terms of different disciplines and theories that have been influential, beginning with...This article traces the evolution of the field of second language acquisition/development(SLA/SLD). It chronicles the evolution in terms of different disciplines and theories that have been influential, beginning with the origin of SLA/SLD in linguistic thinking and expanding its scope of inquiry to psycholinguistics. It has developed further with the disciplines of anthropology and sociology holding sway. More recently, newer cognitive theories have been influential. The article discusses the recent call for a transdisciplinary approach. More specifically, the author promotes the adoption of complex dynamic systems theory, in keeping with non-reductionist systems thinking. Not only is this sociocognitive theory an interdisciplinary theory, but it also highlights the dynamic, variable, nonlinear nature of second language development. This it does within an ecological conception of development, which insists on the relevance of context. It also maintains that SLA/SLD is not a matter of input becoming output, but rather that language patterns emerge from the interaction of its users, given the affordances that they perceive. The article concludes with a discussion of several instructional issues.展开更多
基金Project supported by the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(Grant No.GZC20231050)the National Natural Science Foundation of China(Grant Nos.12175193 and 11905183)the 13th Five-year plan for Education Science Funding of Guangdong Province(Grant No.2021GXJK349)。
文摘For non-stationary complex dynamic systems,a standardized algorithm is developed to compute time correlation functions,addressing the limitations of traditional methods reliant on the stationary assumption.The proposed algorithm integrates two-point and multi-point time correlation functions into a unified framework.Further,it is verified by a practical application in complex financial systems,demonstrating its potential in various complex dynamic systems.
文摘This paper describes how scientist-philosopher Charles S. Peirce （1839-1914） develops theories that lead eventually to contemporary complex/dynamic systems. In both Peirce and complexity theory, possible bridges appear between analogical/reductionist representations and metaphorical/creative symbols. In complex/dynamic terms, Peirce＇s scientific theories become a conceptual egg that hatches a century later in complex systems, which is relevant in turn to environmental science and engineering.
文摘This study employs a Q methodology to explore the developmental routines of oral English ability for 12 English major students in China inspired by Complex and Dynamic Systems Theory(CDST).The data analysis suggests the next findings:(1)two developmental patterns emerge as the gradual improvement and the strong phase shift influenced by internal and external factors for interactions among different subsystems;(2)guided by CDST,the study proves the importance of self-organization and initial condition in previous studies.According to the above findings,It is highly suggested for teachers to form a holistic view of students’oral English development concerning the non-linear characteristic and individual differences.
文摘Traditional biomechanical analyses of human movement are generally derived from linear mathematics.While these methods can be useful in many situations,they do not describe behaviors in human systems that are predominately nonlinear.For this reason,nonlinear analysis methods based on a dynamical systems approach have become more prevalent in recent literature.These analysis techniques have provided new insights into how systems(1) maintain pattern stability,(2) transition into new states,and(3) are governed by short-and long-term(fractal) correlational processes at different spatio-temporal scales.These different aspects of system dynamics are typically investigated using concepts related to variability,stability,complexity,and adaptability.The purpose of this paper is to compare and contrast these different concepts and demonstrate that,although related,these terms represent fundamentally different aspects of system dynamics.In particular,we argue that variability should not uniformly be equated with stability or complexity of movement.In addition,current dynamic stability measures based on nonlinear analysis methods(such as the finite maximal Lyapunov exponent) can reveal local instabilities in movement dynamics,but the degree to which these local instabilities relate to global postural and gait stability and the ability to resist external perturbations remains to be explored.Finally,systematic studies are needed to relate observed reductions in complexity with aging and disease to the adaptive capabilities of the movement system and how complexity changes as a function of different task constraints.
基金This work was supported by the EPSRC(No.GR/R50738/01).
文摘Parameter identification is a key requirement in the field of automated control of unmanned excavators （UEs）. Furthermore, the UE operates in unstructured, often hazardous environments, and requires a robust parameter identification scheme for field applications. This paper presents the results of a research study on parameter identification for UE. Three identification methods, the Newton-Raphson method, the generalized Newton method, and the least squares method are used and compared for prediction accuracy, robustness to noise and computational speed. The techniques are used to identify the link parameters （mass, inertia, and length） and friction coefficients of the full-scale UE. Using experimental data from a full-scale field UE, the values of link parameters and the friction coefficient are identified. Some of the identified parameters are compared with measured physical values. Furthermore, the joint torques and positions computed by the proposed model using the identified parameters are validated against measured data. The comparison shows that both the Newton-Raphson method and the generalized Newton method are better in terms of prediction accuracy. The Newton-Raphson method is computationally efficient and has potential for real time application, but the generalized Newton method is slightly more robust to measurement noise. The experimental data were obtained in collaboration with QinetiQ Ltd.
文摘Let Δυ be the unit ball in ?υ with center 0 (the origin of υ) and let F:Δυ→?υbe a holomorphic map withF(0) = 0. This paper is to study the fixed point multiplicities at the origin 0 of the iteratesF i =F°?°F (i times),i = 1,2,.... This problem is easy when υ = 1, but it is very complicated when υ > 1. We will study this problem generally.
基金E.M.acknowledges the financial support of the Eck Institute for Global HealthUniversity of Notre Dame,while S.M.thanks the British Academy for supporting the undertaking of this work。
文摘The current global attempts to control the so-called“Neglected Tropical Diseases(NTDs)”have the potential to significantly reduce the morbidity suffered by some of the world’s poorest communities.However,the governance of these control programmes is driven by a managerial rationality that assumes predictability of proposed interventions,and which thus primarily seeks to improve the cost-effectiveness of implementation by measuring performance in terms of pre-determined outputs.Here,we argue that this approach has reinforced the narrow normal-science model for controlling parasitic diseases,and in doing so fails to address the complex dynamics,uncertainty and socio-ecological context-specificity that invariably underlie parasite transmission.We suggest that a new governance approach is required that draws on a combination of non-equilibrium thinking about the operation of complex,adaptive,systems from the natural sciences and constructivist social science perspectives that view the accumulation of scientific knowledge as contingent on historical interests and norms,if more effective control approaches sufficiently sensitive to local disease contexts are to be devised,applied and managed.At the core of this approach is an emphasis on the need for a process that assists with the inclusion of diverse perspectives,social learning and deliberation,and a reflexive approach to addressing system complexity and incertitude,while balancing this flexibility with stability-focused structures.We derive and discuss a possible governance framework and outline an organizational structure that could be used to effectively deal with the complexity of accomplishing global NTD control.We also point to examples of complexity-based management structures that have been used in parasite control previously,which could serve as practical templates for developing similar governance structures to better manage global NTD control.Our results hold important wider implications for global health policy aiming to effectively control and eradicate parasitic diseases across the world.
文摘This article traces the evolution of the field of second language acquisition/development(SLA/SLD). It chronicles the evolution in terms of different disciplines and theories that have been influential, beginning with the origin of SLA/SLD in linguistic thinking and expanding its scope of inquiry to psycholinguistics. It has developed further with the disciplines of anthropology and sociology holding sway. More recently, newer cognitive theories have been influential. The article discusses the recent call for a transdisciplinary approach. More specifically, the author promotes the adoption of complex dynamic systems theory, in keeping with non-reductionist systems thinking. Not only is this sociocognitive theory an interdisciplinary theory, but it also highlights the dynamic, variable, nonlinear nature of second language development. This it does within an ecological conception of development, which insists on the relevance of context. It also maintains that SLA/SLD is not a matter of input becoming output, but rather that language patterns emerge from the interaction of its users, given the affordances that they perceive. The article concludes with a discussion of several instructional issues.
