In this paper, an integrated validation method and process are developed for multivariate dynamic systems. The principal component analysis approach is used to address multivariate correlation and dimensionality reduc...In this paper, an integrated validation method and process are developed for multivariate dynamic systems. The principal component analysis approach is used to address multivariate correlation and dimensionality reduction, the dynamic time warping and correlation coefficient are used for error assessment, and the subject matter experts (SMEs)’ opinions and principal component analysis coefficients are incorporated to provide the overall rating of the dynamic system. The proposed method and process are successfully demonstrated through a vehicle dynamic system problem.展开更多
This paper presents the forward displacement analysis of an 8-PSS(prismatic-spherical-spherical)redundant parallel manipulator whose moving platform is linked to the base platform by eight kinemtic chains consisting o...This paper presents the forward displacement analysis of an 8-PSS(prismatic-spherical-spherical)redundant parallel manipulator whose moving platform is linked to the base platform by eight kinemtic chains consisting of a PSS joint and a strut with fixed length.A general approximation algorithm is used to solve the problem.To avoid the extraction of root in the approximation process,the forward displacement analysis of the 8-PSS redundant parallel manipulator is transformed into another equivalent problem on the assumption that the strut is extensible while the slider is fixed.The problem is solved by a modified approximation algorithm which predicates that the manipulator will move along a pose vector to reduce the difference between the desired configuration and an instantaneous one,and the best movement should be with minimum norm and least quadratic sum.The characteristic of this modified algorithm is that its convergence domain is larger than that of the general approximation algorithm.Simulation results show that the modelified algorithm is general and can be used for the forward displacement analysis of the redundant parallel manipulator actuated by a revolute joint.展开更多
Climate change has been linked to well-documented changes in physiology, phenology, species distributions, and in some cases, extinction. Projections of future change point to dramatic shifts in the states of many eco...Climate change has been linked to well-documented changes in physiology, phenology, species distributions, and in some cases, extinction. Projections of future change point to dramatic shifts in the states of many ecosystems. Aceommodating these shifts to effectively conserve biodiversity in the context of uncertain climate regimes represents one of the most difficult challenges faced by conservation planners. A number of adaptation strategies have been proposed for managing species and ecosystems in a changing climate. However, there has been little guidance available on integrating climate change adaptation strategies into contemporary conservation planning frameworks. The paper reviews the different approaches being used to integrate climate change adaptation into conservation planning, broadly categorizing strategies as continuing and extending on ＂best practice＂ principles and those that integrate species vulnerability assessments into conservation planning. We describe the characteristics of a good adaptation strategy emphasizing the importance of incorporating clear principles of flexibility and efficiency, accounting for uncertainty, integrating human response to climate change and understanding trade-offs.展开更多
基金supported by the National Natural Science Fundation of China (No. 51075262)the New Century Excellent Talents in University Program (No. NCET-08-0361)the Fund for the Doctoral Program of Higher Education (No. 200802480036), China
文摘In this paper, an integrated validation method and process are developed for multivariate dynamic systems. The principal component analysis approach is used to address multivariate correlation and dimensionality reduction, the dynamic time warping and correlation coefficient are used for error assessment, and the subject matter experts (SMEs)’ opinions and principal component analysis coefficients are incorporated to provide the overall rating of the dynamic system. The proposed method and process are successfully demonstrated through a vehicle dynamic system problem.
基金Funded by the National Natural Science Foundation of China(Grant No.50905102)the China Postdoctoral Science Foundation(Grant No.200801199)the Natural Science Foundation of Guangdong Province(Grant No.8351503101000001)
文摘This paper presents the forward displacement analysis of an 8-PSS(prismatic-spherical-spherical)redundant parallel manipulator whose moving platform is linked to the base platform by eight kinemtic chains consisting of a PSS joint and a strut with fixed length.A general approximation algorithm is used to solve the problem.To avoid the extraction of root in the approximation process,the forward displacement analysis of the 8-PSS redundant parallel manipulator is transformed into another equivalent problem on the assumption that the strut is extensible while the slider is fixed.The problem is solved by a modified approximation algorithm which predicates that the manipulator will move along a pose vector to reduce the difference between the desired configuration and an instantaneous one,and the best movement should be with minimum norm and least quadratic sum.The characteristic of this modified algorithm is that its convergence domain is larger than that of the general approximation algorithm.Simulation results show that the modelified algorithm is general and can be used for the forward displacement analysis of the redundant parallel manipulator actuated by a revolute joint.
文摘Climate change has been linked to well-documented changes in physiology, phenology, species distributions, and in some cases, extinction. Projections of future change point to dramatic shifts in the states of many ecosystems. Aceommodating these shifts to effectively conserve biodiversity in the context of uncertain climate regimes represents one of the most difficult challenges faced by conservation planners. A number of adaptation strategies have been proposed for managing species and ecosystems in a changing climate. However, there has been little guidance available on integrating climate change adaptation strategies into contemporary conservation planning frameworks. The paper reviews the different approaches being used to integrate climate change adaptation into conservation planning, broadly categorizing strategies as continuing and extending on ＂best practice＂ principles and those that integrate species vulnerability assessments into conservation planning. We describe the characteristics of a good adaptation strategy emphasizing the importance of incorporating clear principles of flexibility and efficiency, accounting for uncertainty, integrating human response to climate change and understanding trade-offs.
