Path determination is a fundamental problem of operations research. Current solutions mainly focus on the shortest and longest paths. We consider a more generalized problem; specifically, we consider the path problem ...Path determination is a fundamental problem of operations research. Current solutions mainly focus on the shortest and longest paths. We consider a more generalized problem; specifically, we consider the path problem with desired bounded lengths （DBL path problem）. This problem has extensive applications; however, this problem is much harder, especially for large-scale problems. An effective approach to this problem is equivalent simplification. We focus on simplifying the problem in acyclic networks and creating a path length model that simplifies relationships between various path lengths. Based on this model, we design polynomial algorithms to compute the shortest, longest, second shortest, and second longest paths that traverse any arc. Furthermore, we design a polynomial algorithm for the equivalent simplification of the is O（m）, where m is the number of arcs. DBL path problem. The complexity of the algorithm展开更多
The theoretical results of axial force distribution models differ greatly from tests because of the complication of the rock type material. A three-parameter combined-power model is proposed by curves fitting the test...The theoretical results of axial force distribution models differ greatly from tests because of the complication of the rock type material. A three-parameter combined-power model is proposed by curves fitting the test data recorded from the pull tests on anchoring bars used in different engineering projects. Based on the comparison of the mechanical characteristics of shaft anchors and prestressed tendons, a two-parameter combined-power function model for prestressed tendons is proposed. The bounded length derived from the model and the suggested values of the parameters are also proposed. Compared with the Gaussian model, the three-parameter combined-power model is more precise and simple in expression. Results also suggest that the bounded length calculated from the average stress method is not safe enough.展开更多
Several problems studied by professor R. V. Kadison are shown to be closely related. The problems were originally formulated in the contexts of homomorphisms of C*-algebras, cohomology of von Neumann algebras and pert...Several problems studied by professor R. V. Kadison are shown to be closely related. The problems were originally formulated in the contexts of homomorphisms of C*-algebras, cohomology of von Neumann algebras and perturbations of C*-algebras. Recent research by G. Pisier has demonstrated that all of the problems considered are related to the question of whether all C*-algebras have finite length.展开更多
基金Natural Science Foundation of China(No. 71171079 and 71271081)the Natural Science Foundation of Jiangxi Provincial Department of Science and Technology in China(No. 20151BAB211015)the Jiangxi Research Center of Soft Science for Water Security& Sustainable Development for financially supporting this work
文摘Path determination is a fundamental problem of operations research. Current solutions mainly focus on the shortest and longest paths. We consider a more generalized problem; specifically, we consider the path problem with desired bounded lengths （DBL path problem）. This problem has extensive applications; however, this problem is much harder, especially for large-scale problems. An effective approach to this problem is equivalent simplification. We focus on simplifying the problem in acyclic networks and creating a path length model that simplifies relationships between various path lengths. Based on this model, we design polynomial algorithms to compute the shortest, longest, second shortest, and second longest paths that traverse any arc. Furthermore, we design a polynomial algorithm for the equivalent simplification of the is O（m）, where m is the number of arcs. DBL path problem. The complexity of the algorithm
基金This paper is supported by the Foundation for Research Project of ChinaCommunications Second Highway Survey Design and ResearchInstitute .
文摘The theoretical results of axial force distribution models differ greatly from tests because of the complication of the rock type material. A three-parameter combined-power model is proposed by curves fitting the test data recorded from the pull tests on anchoring bars used in different engineering projects. Based on the comparison of the mechanical characteristics of shaft anchors and prestressed tendons, a two-parameter combined-power function model for prestressed tendons is proposed. The bounded length derived from the model and the suggested values of the parameters are also proposed. Compared with the Gaussian model, the three-parameter combined-power model is more precise and simple in expression. Results also suggest that the bounded length calculated from the average stress method is not safe enough.
文摘Several problems studied by professor R. V. Kadison are shown to be closely related. The problems were originally formulated in the contexts of homomorphisms of C*-algebras, cohomology of von Neumann algebras and perturbations of C*-algebras. Recent research by G. Pisier has demonstrated that all of the problems considered are related to the question of whether all C*-algebras have finite length.
