The rapid development of the automobile industry and the relative lag of the road construction have constituted a prominent contradiction all over the world, particularly, in most of large cities. To cope with it, ele...The rapid development of the automobile industry and the relative lag of the road construction have constituted a prominent contradiction all over the world, particularly, in most of large cities. To cope with it, elevated roads have been built in many cities both at home and abroad. However, traffic jams frequently appear on elevated roads immediately after the completion of their construction. The awkward situation mainly results from the planning bug or the unsuitable control, apart from drastic increase in transportation demand. Elevated roads,展开更多
We have proposed a nonlinear effective medium approximation(EMA)method to estimate the bulk effective conductivities of weakly nonlinear composite media,which obey a current-field relation of the form J=σE+X|E|2 E.As...We have proposed a nonlinear effective medium approximation(EMA)method to estimate the bulk effective conductivities of weakly nonlinear composite media,which obey a current-field relation of the form J=σE+X|E|2 E.As an example in three dimensions,we apply the EMA method to deal with a spherical inclusion in a host and derive the approximate analytic formulas of nonlinear effective response,which are suitable for the larger volume fraction of spherical inclusion.From our results,we can exactly obtain the generalized Landau formulas in the dilute limit.展开更多
In this paper,a derivation of the macroscopic mean field theory of the cellular automaton(CA)model of highway traffic flow starting from the microscopic dynamical point of view is presented.Starting from an equation d...In this paper,a derivation of the macroscopic mean field theory of the cellular automaton(CA)model of highway traffic flow starting from the microscopic dynamical point of view is presented.Starting from an equation describing the time evolution of the Boolean state variable at each site of the basic CA model,and using a two-site approximation for the multi-site correlation functions,a dynamical mapping between the macroscopic average speeds v(t+1)and v(t)at different time can be derived.Mean field results consistent with the simulation data are obtained by considering the attractors of the mapping and their corresponding basins.展开更多
文摘The rapid development of the automobile industry and the relative lag of the road construction have constituted a prominent contradiction all over the world, particularly, in most of large cities. To cope with it, elevated roads have been built in many cities both at home and abroad. However, traffic jams frequently appear on elevated roads immediately after the completion of their construction. The awkward situation mainly results from the planning bug or the unsuitable control, apart from drastic increase in transportation demand. Elevated roads,
基金Supported by the National Natural Science Foundation of China under Grant No.19834070the National Postdoctoral Science Foundation of China.
文摘We have proposed a nonlinear effective medium approximation(EMA)method to estimate the bulk effective conductivities of weakly nonlinear composite media,which obey a current-field relation of the form J=σE+X|E|2 E.As an example in three dimensions,we apply the EMA method to deal with a spherical inclusion in a host and derive the approximate analytic formulas of nonlinear effective response,which are suitable for the larger volume fraction of spherical inclusion.From our results,we can exactly obtain the generalized Landau formulas in the dilute limit.
基金Supported by the Chinese National Basic Research Project"Nonlinear Science"the National Natural Science Foundation of China under Grant No.49474216the Science Foundation of Shanghai on Traffic Problem Research.
文摘In this paper,a derivation of the macroscopic mean field theory of the cellular automaton(CA)model of highway traffic flow starting from the microscopic dynamical point of view is presented.Starting from an equation describing the time evolution of the Boolean state variable at each site of the basic CA model,and using a two-site approximation for the multi-site correlation functions,a dynamical mapping between the macroscopic average speeds v(t+1)and v(t)at different time can be derived.Mean field results consistent with the simulation data are obtained by considering the attractors of the mapping and their corresponding basins.
