基于改进TOPSIS的轨道交通建设时序研究

为明确城市轨道交通线网中各条线路的建设时序,构建相应的影响因素指标体系,提出一种基于TOPSIS理念的改进决策算法。该方法首先通过指标变换将理想解绝对化;其次建立决策方案到绝对理想解和绝对负理想解的加权距离最优化模型,运用拉格朗日乘子法求解模型得到最优权向量;然后引入"垂直距离"代替传统"欧式距离"的贴近度算法,通过测算垂直距离确定最优建设时序方案。最后对成都市轨道交通线网进行实例分析。结果表明:运用改进的决策算法所确定的结果与实际建设时序一致,且该算法能有效避免TOPSIS模型中的逆序、权重取值主观化、欧式距离自身缺陷等问题,说明该模型能有效支撑城市轨道交通线网建设时序的综合决策。

Construction Sequence of Urban Rail Transit System Based on Improved Topsis Model

To determine the construction sequence of each line in rail transit network,this paper constitutes an influencing factor system of rail transit construction sequence and proposes an improving decision-making method of construction schedule based on TOPSIS. First the index transformation is used to absolutize the ideal solution,and the optimized model of weighed distance from each scheme to absolute positive and negative ideal scheme is established. Then,with lagrangian multiplier method,the model is employed to get optimal weight vector. Afterwards,the proximity algorithm adopting "Vertical distance"to substitute Euclid distance is brought in to calculate the distance to determine the optimal construction sequence. Finally,through the case analysis of Chengdu city rail transit network,the results show that the scheme determined by the improving decision-making method is basically identical to the actual construction sequence,and this method is proved effective in avoiding inverted sequence,weight valuing subjectivity and the insufficiency of Euclid distance. The model is capable of supporting the comprehensive decision-making of rail transit construction sequence.