Nowadays,the main communication object of Internet is human-human.But it is foreseeable that in the near future any object will have a unique identification and can be addressed and connected.The Internet will expand ...Nowadays,the main communication object of Internet is human-human.But it is foreseeable that in the near future any object will have a unique identification and can be addressed and connected.The Internet will expand to the Internet of Things.IPv6 is the cornerstone of the Internet of Things.In this paper,we investigate a fast active worm,referred to as topological worm,which can propagate twice to more than three times faster than a traditional scan-based worm.Topological worm spreads over AS-level network topology,making traditional epidemic models invalid for modeling the propagation of it.For this reason,we study topological worm propagation relying on simulations.First,we propose a new complex weighted network model,which represents the real IPv6 AS-level network topology.And then,a new worm propagation model based on the weighted network model is constructed,which describes the topological worm propagation over AS-level network topology.The simulation results verify the topological worm model and demonstrate the effect of parameters on the propagation.展开更多
A revised displacement discontinuity method(DDM) program is developed for the simulation of rock joint propagation and dilatancy analysis. The non-linear joint model used in the program adopts Barton-Bandis normal def...A revised displacement discontinuity method(DDM) program is developed for the simulation of rock joint propagation and dilatancy analysis. The non-linear joint model used in the program adopts Barton-Bandis normal deformation model, Kulhaway shear deformation model and Mohr-Coulomb criterion. The joint propagation criterion is based on the equivalent stress intensity factor which can be obtained by regression analysis. The simulated rock joint propagation accords well with the existing knowledge. The closure and opening of joint is investigated by DDM, and it is shown that if the opening volume of propagated joint is larger than closure volume of the old joint, the joint dilatancy occurs. The dilatancy condition is mainly controlled by the normal stiffness of the rock joint. When the normal stiffness is larger than the critical value, joint dilatancy occurs. The critical normal stiffness of rock joint changes with the joint-load angle, and joint dilatancy is most possible to occur at 30°.展开更多
基金supported by the Ministry of Education Research Project for Returned Talents after Studying Abroadthe Ministry of Education Project of Science and Technology Basic Resource Data Platform(No.507001)+1 种基金International Scientific and Technological Cooperation Program(S2010GR0902)Chinese Universities Scientific Fund(2009RC0502)
文摘Nowadays,the main communication object of Internet is human-human.But it is foreseeable that in the near future any object will have a unique identification and can be addressed and connected.The Internet will expand to the Internet of Things.IPv6 is the cornerstone of the Internet of Things.In this paper,we investigate a fast active worm,referred to as topological worm,which can propagate twice to more than three times faster than a traditional scan-based worm.Topological worm spreads over AS-level network topology,making traditional epidemic models invalid for modeling the propagation of it.For this reason,we study topological worm propagation relying on simulations.First,we propose a new complex weighted network model,which represents the real IPv6 AS-level network topology.And then,a new worm propagation model based on the weighted network model is constructed,which describes the topological worm propagation over AS-level network topology.The simulation results verify the topological worm model and demonstrate the effect of parameters on the propagation.
基金Project(2009318000046) supported by the Western Transport Technical Program of the Ministry of Transport,China
文摘A revised displacement discontinuity method(DDM) program is developed for the simulation of rock joint propagation and dilatancy analysis. The non-linear joint model used in the program adopts Barton-Bandis normal deformation model, Kulhaway shear deformation model and Mohr-Coulomb criterion. The joint propagation criterion is based on the equivalent stress intensity factor which can be obtained by regression analysis. The simulated rock joint propagation accords well with the existing knowledge. The closure and opening of joint is investigated by DDM, and it is shown that if the opening volume of propagated joint is larger than closure volume of the old joint, the joint dilatancy occurs. The dilatancy condition is mainly controlled by the normal stiffness of the rock joint. When the normal stiffness is larger than the critical value, joint dilatancy occurs. The critical normal stiffness of rock joint changes with the joint-load angle, and joint dilatancy is most possible to occur at 30°.
