One of the dynamic phases of the traffic flow is the traffic jam. It appears in traffic flow when the vehicledensity is larger than the critical value. In this paper, a new method is presented to investigate the traff...One of the dynamic phases of the traffic flow is the traffic jam. It appears in traffic flow when the vehicledensity is larger than the critical value. In this paper, a new method is presented to investigate the traffic jam when thevehicle density is smaller than the critical value. In our method, we introduce noise into the traffic system after sufficienttransient time. Under the effect of noise, the traffic jam appears, and the phase transition from tree to synchronized flowoccurs in traffic flow. Our method is tested for the deterministic NaSch traffic model. The simulation results demonstratethat there exist a broad range of lower densities at which the noise effect leading to traffic jam can be observed.展开更多
We propose a new technique for controlling disorder in traffic system. A kind of control signal which can be considered as a perturbation has been designated at a given site (perturbation point) of the single-lane hig...We propose a new technique for controlling disorder in traffic system. A kind of control signal which can be considered as a perturbation has been designated at a given site (perturbation point) of the single-lane highway. When a vehicle passes the perturbation point at a time, the velocity of the vehicle will be changed at the next time by the perturbation. This technique is tested for the deterministic NaSch traffic model. The simulation results indicate that the traffic system can be transited from the disorder states to the order states, such as fixed-point, periodic motion, etc.展开更多
Besides of considering of the maximization of public interest, the benefit of passengers and railway enterprises are both considered and a bi-level programming approach is presented in order to seek the optimal railwa...Besides of considering of the maximization of public interest, the benefit of passengers and railway enterprises are both considered and a bi-level programming approach is presented in order to seek the optimal railway passenger-ticket pricing strategy under the condition of competition among different intercity traffic modes. There are two bi-level programming problems. One bi-level problem is to determine a railway passenger-ticket average price strategy to meet .the objective of maximizing the consumer surplus under the condition of multi-modal transportation with elastic demand. The other bi-level problem is to determine the price of different kinds of the passenger trains to meet the objective of maximizing the railway revenue where the average price and the demand of the railway is determined. A heuristic algorithm for the two bi-level programming models is also proposed. Finally the applications of the model and its algorithm are illustrated with a numerical example.展开更多
The traditional user-optimal assignment model assumed that the traffic information is perfect, howerver, the link travel cost is Always uncertain or fuzzy in real situations.The paper gives a modified Frank-Wolfe meth...The traditional user-optimal assignment model assumed that the traffic information is perfect, howerver, the link travel cost is Always uncertain or fuzzy in real situations.The paper gives a modified Frank-Wolfe method for fuzzy user-optimal route choice problem.The shortest-path algorithm in F-W is solved by an order relation (FSA) method between fuzzy travel costs. The results of a simple example show that the method is practical.展开更多
With the deepen of market competition, product pricing and production decision problem in many firms have become more and more important. A bilevel model is proposed to describe the pricing and production decisions wi...With the deepen of market competition, product pricing and production decision problem in many firms have become more and more important. A bilevel model is proposed to describe the pricing and production decisions with fuzzy demand and fuzzy cost parameters. The upper level is to determine the optimal price and production quantity with capacity constraints. Using this information, the lower level problem tries to structure a response (the distribution pattern of customers (or markets)) that will satisfy his demand at minimum cost. And after transforming the fuzzy numbers into the crisp value by Graded Mean Integration Representation method, the solution algorithm based on difference method is given. Finally, the application of the model and its algorithm are illustrated with a simple example.展开更多
基金国家自然科学基金，the Research Award Program，教育部优秀青年教师资助计划
文摘One of the dynamic phases of the traffic flow is the traffic jam. It appears in traffic flow when the vehicledensity is larger than the critical value. In this paper, a new method is presented to investigate the traffic jam when thevehicle density is smaller than the critical value. In our method, we introduce noise into the traffic system after sufficienttransient time. Under the effect of noise, the traffic jam appears, and the phase transition from tree to synchronized flowoccurs in traffic flow. Our method is tested for the deterministic NaSch traffic model. The simulation results demonstratethat there exist a broad range of lower densities at which the noise effect leading to traffic jam can be observed.
文摘We propose a new technique for controlling disorder in traffic system. A kind of control signal which can be considered as a perturbation has been designated at a given site (perturbation point) of the single-lane highway. When a vehicle passes the perturbation point at a time, the velocity of the vehicle will be changed at the next time by the perturbation. This technique is tested for the deterministic NaSch traffic model. The simulation results indicate that the traffic system can be transited from the disorder states to the order states, such as fixed-point, periodic motion, etc.
文摘Besides of considering of the maximization of public interest, the benefit of passengers and railway enterprises are both considered and a bi-level programming approach is presented in order to seek the optimal railway passenger-ticket pricing strategy under the condition of competition among different intercity traffic modes. There are two bi-level programming problems. One bi-level problem is to determine a railway passenger-ticket average price strategy to meet .the objective of maximizing the consumer surplus under the condition of multi-modal transportation with elastic demand. The other bi-level problem is to determine the price of different kinds of the passenger trains to meet the objective of maximizing the railway revenue where the average price and the demand of the railway is determined. A heuristic algorithm for the two bi-level programming models is also proposed. Finally the applications of the model and its algorithm are illustrated with a numerical example.
文摘The traditional user-optimal assignment model assumed that the traffic information is perfect, howerver, the link travel cost is Always uncertain or fuzzy in real situations.The paper gives a modified Frank-Wolfe method for fuzzy user-optimal route choice problem.The shortest-path algorithm in F-W is solved by an order relation (FSA) method between fuzzy travel costs. The results of a simple example show that the method is practical.
文摘With the deepen of market competition, product pricing and production decision problem in many firms have become more and more important. A bilevel model is proposed to describe the pricing and production decisions with fuzzy demand and fuzzy cost parameters. The upper level is to determine the optimal price and production quantity with capacity constraints. Using this information, the lower level problem tries to structure a response (the distribution pattern of customers (or markets)) that will satisfy his demand at minimum cost. And after transforming the fuzzy numbers into the crisp value by Graded Mean Integration Representation method, the solution algorithm based on difference method is given. Finally, the application of the model and its algorithm are illustrated with a simple example.
