Performance index mance evaluation, and is the is the standard of perfor- foundation of both perfor- mance analysis and optimal design for the parallel manipulator. Seeking the suitable kinematic indices is always an ...Performance index mance evaluation, and is the is the standard of perfor- foundation of both perfor- mance analysis and optimal design for the parallel manipulator. Seeking the suitable kinematic indices is always an important and challenging issue for the parallel manipulator. So far, there are extensive studies in this field, but few existing indices can meet all the requirements, such as simple, intuitive, and universal. To solve this problem, the matrix orthogonal degree is adopted, and generalized transmission indices that can evaluate motion/force trans- missibility of fully parallel manipulators are proposed. Transmission performance analysis of typical branches, end effectors, and parallel manipulators is given to illus- trate proposed indices and analysis methodology. Simula- tion and analysis results reveal that proposed transmission indices possess significant advantages, such as normalized finite （ranging from 0 to l）, dimensionally homogeneous, frame-free, intuitive and easy to calculate. Besides, pro- posed indices well indicate the good transmission region and relativity to the singularity with better resolution than the traditional local conditioning index, and provide a novel tool for kinematic analysis and optimal design of fully parallel manipulators.展开更多
A novel topological index W F is defined by the matrices X,W and L as W F=XWL.The topological index WF based on the distance-related matrix of molecular graphs is used to code the structural environment of each atom...A novel topological index W F is defined by the matrices X,W and L as W F=XWL.The topological index WF based on the distance-related matrix of molecular graphs is used to code the structural environment of each atom-type in a molecular graph.Good QSPR models have been obtained for standard formation enthalpy of methyl halides.The result indicates that the idea of using multiple matrices to define the distance-related matrix topological index is valid.展开更多
In order to compare the aviation network of mid-south,northwest and southwest of China to reveal the structure similarity and difference for providing quantitative evidence to construct regional aviation network and i...In order to compare the aviation network of mid-south,northwest and southwest of China to reveal the structure similarity and difference for providing quantitative evidence to construct regional aviation network and improve its structure,hierarchical index model of regional aviation network was established through dividing the aviation network into layers to research its structure characters.Data matrixes were defined to record the basic state of regional aviation network.Index matrixes were constructed to describe the quantitative features of regional aviation network.On the basis of these indexes,several structure indexes of all layers of aviation network were calculated to show the structure features of aviation network,such as ratio of passenger volume within the region with across the region,share rate of passenger volume among layers,ratio of average number of airline for each airport,ratio of average passenger volume for each airline and ratio of airline rate.According to the statistical data,similar structure of share rate of passenger volume among layers and average passenger volume for each airline in their regional aviation network was found after calculating.But on the side of ratio of passenger volume within the region with across the region,ratio of average number of airlines for each airport and ratio of airline rate were different.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.51575292,51475252,91648107)National Key Technology Research and Development Program of China(Grant No.2105BAF19B00)National Science and Technology Major Project of China(Grant No.2016ZX04004004)
文摘Performance index mance evaluation, and is the is the standard of perfor- foundation of both perfor- mance analysis and optimal design for the parallel manipulator. Seeking the suitable kinematic indices is always an important and challenging issue for the parallel manipulator. So far, there are extensive studies in this field, but few existing indices can meet all the requirements, such as simple, intuitive, and universal. To solve this problem, the matrix orthogonal degree is adopted, and generalized transmission indices that can evaluate motion/force trans- missibility of fully parallel manipulators are proposed. Transmission performance analysis of typical branches, end effectors, and parallel manipulators is given to illus- trate proposed indices and analysis methodology. Simula- tion and analysis results reveal that proposed transmission indices possess significant advantages, such as normalized finite （ranging from 0 to l）, dimensionally homogeneous, frame-free, intuitive and easy to calculate. Besides, pro- posed indices well indicate the good transmission region and relativity to the singularity with better resolution than the traditional local conditioning index, and provide a novel tool for kinematic analysis and optimal design of fully parallel manipulators.
文摘A novel topological index W F is defined by the matrices X,W and L as W F=XWL.The topological index WF based on the distance-related matrix of molecular graphs is used to code the structural environment of each atom-type in a molecular graph.Good QSPR models have been obtained for standard formation enthalpy of methyl halides.The result indicates that the idea of using multiple matrices to define the distance-related matrix topological index is valid.
文摘In order to compare the aviation network of mid-south,northwest and southwest of China to reveal the structure similarity and difference for providing quantitative evidence to construct regional aviation network and improve its structure,hierarchical index model of regional aviation network was established through dividing the aviation network into layers to research its structure characters.Data matrixes were defined to record the basic state of regional aviation network.Index matrixes were constructed to describe the quantitative features of regional aviation network.On the basis of these indexes,several structure indexes of all layers of aviation network were calculated to show the structure features of aviation network,such as ratio of passenger volume within the region with across the region,share rate of passenger volume among layers,ratio of average number of airline for each airport,ratio of average passenger volume for each airline and ratio of airline rate.According to the statistical data,similar structure of share rate of passenger volume among layers and average passenger volume for each airline in their regional aviation network was found after calculating.But on the side of ratio of passenger volume within the region with across the region,ratio of average number of airlines for each airport and ratio of airline rate were different.
