Optimization model of number of scheduled freight train formation cars
The determination of the number of formation cars is an important part of making a scheduled freight train plan, and it also has a large influence on the benefits of railway freight transportation. First, the influences that affect the number of formation cars are analyzed. Secondly, taking the maximum freight transport benefits as an objective, and comprehensively considering the primary factors that include service frequency of freight trains, section traction weight, effective length of arrival-departure tracks, and so on, this paper establishes the optimization model of the number of scheduled freight train formation cars. Finally, the solving method for the model is presented, and a case is given to show the solution process. It provides a reference for decision-makers of railway freight transportation.
A mathematical model for the fixed-time traffic control problem
Abstract The paper deals with the fixed-time traffic control problem, which consists of finding a periodic schedule for the signals controlling the vehicular traffic in a system of intersections. A traffic model is used which allows for constraints on green durations, conflicts and coordinations. The resulting mathematical model is formulated as an extension of the feasible differential problem of network flow theory over a special graph associated with the intersection system. The fixed-time traffic control problem is proved to be NP-complete in general. A specialized algorithm is proposed for its solution; moreover, an alternative solution method based on mixed-integer linear programming is given. Finally, a real example is modelled and solved.
Representation of systems disturbed by wide band noise
In this paper, a method of handling and working with wide band noise is developed. We represent wide band noise as a distributed delay of white noise and use it to reduce a nonlinear system disturbed by wide band noise to a nonlinear system disturbed by white noise. An application of this reduction to a nonlinear filtering problem under a wide band noise disturbance is discussed.