Abstract: An abstract cost function of the streamline network is developed based on the basic features of the construction and operation of the streamline network. In order to lower the logistics cost and improve the logistics efficiency, an optimization model with capacity constraint is presented to minimize the total cost, including constructing cost and operating cost. The model is converted into a variational inequality, and the equivalence between the variational inequality and the solution of optimization model is proven. An optimum logistics organization scheme is obtained by solving the variational inequality. The results of a numerical example show reasonability and feasibility of the proposed model and method, and it can help enterprises operate their logistics network.

Key words: stream line network, the third logistics, variational inequalities, modified projection algorithm

摘要： 通过分析流线网络建设与运营的基本特征，构建了流线网络的抽象成本函数，为了降低物流成本和提高物流效率，建立以能力供给为约束，以网络建设和运营成本最小为目标的优化模型。将模型转化为相应的变分不等式，证明变分不等式与优化模型解的等价性，通过解变分不等式得到最优物流组织方案，算例验证了模型合理性和可行性，为企业对物流网络的经营提供理论支持。

关键词: 流线网络, 第三方物流, 变分不等式, 修正投影算法