The minimum action method(MAM)is to calculate the most probable transition path in randomly perturbed stochastic dynamics,based on the idea of action minimization in the path space.The accuracy of the numerical path b...The minimum action method(MAM)is to calculate the most probable transition path in randomly perturbed stochastic dynamics,based on the idea of action minimization in the path space.The accuracy of the numerical path between different metastable states usually suffers from the“clustering problem”near fixed points.The adaptive minimum action method(aMAM)solves this problem by relocating image points equally along arc-length with the help of moving mesh strategy.However,when the time interval is large,the images on the path may still be locally trapped around the transition state in a tangle,due to the singularity of the relationship between arc-length and time at the transition state.Additionally,in most non-gradient dynamics,the tangent direction of the path is not continuous at the transition state so that a geometric corner forms,which brings extra challenges for the aMAM.In this note,we improve the aMAM by proposing a better monitor function that does not contain the numerical approximation of derivatives,and taking use of a generalized scheme of the Euler-Lagrange equation to solve the minimization problem,so that both the path-tangling problem and the non-smoothness in parametrizing the curve do not exist.To further improve the accuracy,we apply the Weighted Essentially nonoscillatory(WENO)method for the interpolation to achieve better performance.Numerical examples are presented to demonstrate the advantages of our new method.展开更多
As is universally acknowledged,educators have endeavored for ages to seek the more effective teaching method.Then action research has become a tool which is frequently applied to the teaching practice aiming to locate...As is universally acknowledged,educators have endeavored for ages to seek the more effective teaching method.Then action research has become a tool which is frequently applied to the teaching practice aiming to locate the teaching mode satisfactory to both teachers and students.The English majors are required to pass the TEM-4 exam when they are sophomores.It is essential for them to acquire the effective learning skills from reading classes.But it seems that vocabulary and grammar study—so called the traditional teaching method prove boring to students.Therefore,the tapestry approach is put forward.But the question is though the tapestry approach stimulates students’interest,can it can improve their English level?In order to figure out the result,two classes will be chosen in this research—one is controlled class,the other is experimental class.The traditional teaching method and the tapestry approach will be used in these two classes respectively.The experiment will last one semester.The students will be tested on two same TEM-4 papers at the beginning and at the end of the semester.The data will be collected for comparison.If the experimental class get the higher scores in the TEM-4 paper,it demonstrates that the tapestry approach is successful in balancing the need for interests and the need for English improvement.展开更多
A higher order boundary dement method （HOBEM） is implemented for wave-current action on structures. The freeterm coefficient and Cauchy principal value （ GPV） integrals are computed by direct methods. Numerical ex...A higher order boundary dement method （HOBEM） is implemented for wave-current action on structures. The freeterm coefficient and Cauchy principal value （ GPV） integrals are computed by direct methods. Numerical experiments are carried out to validate the computation of free-term coefficient and GPV integrals. The results show that the computation precision of free-term coefficient is very high for various bodies, even with edges and corners, and the convergence speed is fast for CPV integrals for different meshes. The comparison of the second order mean drift force due to wave-current action on a uniform cylinder is made with an analytic solution. It is found that good agreement exists between the present calculation and the analytic solutions. Finally, the numerical code is applied for computing wave-current action on Snorrc TLP.展开更多
In this paper, the author presents an overview of the history and trends of the Research Methods in Second Language Acquisition in recent years; and then, combining the present situation in China, indicates that the a...In this paper, the author presents an overview of the history and trends of the Research Methods in Second Language Acquisition in recent years; and then, combining the present situation in China, indicates that the approach of Action Research will be the future trend in research on Computer Assisted Second Language Acquisition （CASLA）. To explain the author＇s viewpoint, this paper firstly sets out to describe the author＇s understanding of the Research Methods in Second Language Acquisition （SLA）, and then the comprehension of Action Research in CASLA.展开更多
This paper presents the generalized principles of least action of variable mass nonholonomic nonconservative system in noninertial reference frame, proves the equivalence between Holder form and Suslov form, and then ...This paper presents the generalized principles of least action of variable mass nonholonomic nonconservative system in noninertial reference frame, proves the equivalence between Holder form and Suslov form, and then obtains differential equations of motion of variable mass nonholonomic nonconservative system in noninertial reference frame.展开更多
基金The research of Xiang Zhou was supported by grants from the Research Grants Council of the Hong Kong Special Administrative Region,China(Project No.CityU 11304314,11337216,11304715).
文摘The minimum action method(MAM)is to calculate the most probable transition path in randomly perturbed stochastic dynamics,based on the idea of action minimization in the path space.The accuracy of the numerical path between different metastable states usually suffers from the“clustering problem”near fixed points.The adaptive minimum action method(aMAM)solves this problem by relocating image points equally along arc-length with the help of moving mesh strategy.However,when the time interval is large,the images on the path may still be locally trapped around the transition state in a tangle,due to the singularity of the relationship between arc-length and time at the transition state.Additionally,in most non-gradient dynamics,the tangent direction of the path is not continuous at the transition state so that a geometric corner forms,which brings extra challenges for the aMAM.In this note,we improve the aMAM by proposing a better monitor function that does not contain the numerical approximation of derivatives,and taking use of a generalized scheme of the Euler-Lagrange equation to solve the minimization problem,so that both the path-tangling problem and the non-smoothness in parametrizing the curve do not exist.To further improve the accuracy,we apply the Weighted Essentially nonoscillatory(WENO)method for the interpolation to achieve better performance.Numerical examples are presented to demonstrate the advantages of our new method.
文摘As is universally acknowledged,educators have endeavored for ages to seek the more effective teaching method.Then action research has become a tool which is frequently applied to the teaching practice aiming to locate the teaching mode satisfactory to both teachers and students.The English majors are required to pass the TEM-4 exam when they are sophomores.It is essential for them to acquire the effective learning skills from reading classes.But it seems that vocabulary and grammar study—so called the traditional teaching method prove boring to students.Therefore,the tapestry approach is put forward.But the question is though the tapestry approach stimulates students’interest,can it can improve their English level?In order to figure out the result,two classes will be chosen in this research—one is controlled class,the other is experimental class.The traditional teaching method and the tapestry approach will be used in these two classes respectively.The experiment will last one semester.The students will be tested on two same TEM-4 papers at the beginning and at the end of the semester.The data will be collected for comparison.If the experimental class get the higher scores in the TEM-4 paper,it demonstrates that the tapestry approach is successful in balancing the need for interests and the need for English improvement.
基金This researchis supported by Research Fund for Doctoral Programs of Higher Education (Grant No.20030141006) ,and a Program for Changjiang Scholars and Innovative Research Teams in Universities (Grant No.IRT0420)
文摘A higher order boundary dement method （HOBEM） is implemented for wave-current action on structures. The freeterm coefficient and Cauchy principal value （ GPV） integrals are computed by direct methods. Numerical experiments are carried out to validate the computation of free-term coefficient and GPV integrals. The results show that the computation precision of free-term coefficient is very high for various bodies, even with edges and corners, and the convergence speed is fast for CPV integrals for different meshes. The comparison of the second order mean drift force due to wave-current action on a uniform cylinder is made with an analytic solution. It is found that good agreement exists between the present calculation and the analytic solutions. Finally, the numerical code is applied for computing wave-current action on Snorrc TLP.
文摘In this paper, the author presents an overview of the history and trends of the Research Methods in Second Language Acquisition in recent years; and then, combining the present situation in China, indicates that the approach of Action Research will be the future trend in research on Computer Assisted Second Language Acquisition （CASLA）. To explain the author＇s viewpoint, this paper firstly sets out to describe the author＇s understanding of the Research Methods in Second Language Acquisition （SLA）, and then the comprehension of Action Research in CASLA.
文摘This paper presents the generalized principles of least action of variable mass nonholonomic nonconservative system in noninertial reference frame, proves the equivalence between Holder form and Suslov form, and then obtains differential equations of motion of variable mass nonholonomic nonconservative system in noninertial reference frame.
