周三（13 Oct）的SemiTranS报告

[葛颖恩]

大家好！

我们这周的SemiTranS研讨会由章立辉 老师为我们做下面的报告
题目：An Active-Set Algorithm for Discrete Network Design Problems
摘要：
In this paper, we formulate a discrete network design problem as a mathematical program with complementarity constraints and propose an active set algorithm to solve the problem.  Each complementarity constraint requires the product of a pair of nonnegative variables to be zero.  Instead of dealing with this type of constraints directly, the proposed algorithm assigns one of the nonnegative variables in each pair a value of zero.  Doing so reduces the design problem to a user equilibrium problem.  Using the multipliers associated with the constraints forcing nonnegative variables to be zero, the algorithm then constructs and solves binary knapsack problems to make changes to the zero-value assignments in order to improve the system delay.  Numerical experiments with data from networks in the literature indicate that the algorithm is effective and has the potential for solving larger network design problems.

时间：周三、10月13日、下午3点
地点：土木三号楼五楼会议室

通过他的摘要大家可以看到他把离散路网设计问题构建成一个带有线性补约束的数学规划模型；这类模型在交通运输研究中是常用的工具模型。此外，为求解该模型，他提供了一种新的算法。如果在研究中你们的问题也抽象为一个这样的模型，可以和章老师作深入的讨论。

欢迎大家踊跃参加。

葛颖恩