模糊信息下多种类应急物资多周期分配优化模型

考虑灾害的突发性、信息获取的不完全性以及应急救援的紧迫性,引入区间数描述应急物资供给与需求的模糊不确定性,引入三角模糊数刻画路网容量受限情况下每周期的最大物资运输总量,综合考虑灾害、灾区、灾民以及物资等多重因素,引入延迟系数,以应急物资分配的总延迟时间最小化和总系统损失最小化为目标,构建模糊信息条件下考虑多需求点、多配送中心、多物资、多周期、多目标的应急物资动态分配优化决策模型,分析了区间目标函数、区间模糊与三角模糊约束条件的清晰化方法,采用基于二维欧式距离客观赋权模糊算法求解模型,并以青海玉树地震为例对所提出模型的有效性和可行性进行验证。结果表明:所提出的模型能够最大程度地权衡延迟时间与系统损失,形成多周期最优的物资分配方案;现实多周期应急物资分配,时间并不是唯一考虑的因素,需要综合考虑不同应急周期的灾情、灾区、灾民和物资等多种因素对系统总损失造成的影响;重视时间偏好系数,可能使系统总损失增大,表明单一考虑时间偏好系数和损失偏好系数均具有片面性,应该把握选择"度",发挥二者结合的相互促进作用;物资分配方案基于决策者偏好,并考虑每周期不同需求点的易损性、重要性、需求紧急性以及各类应急物资的重要性与时效性差异参数,有利于提高多周期决策的柔性和现实适用性。

Multi-period Optimization Model of Multi-type Emergency Materials Allocation Based on Fuzzy Information

Scientific and efficient material allocation is the essential prerequisites for successful emergency response, and are the important factors that affecting the overall effectiveness of rescue and reducing losses in disaster areas. Due to the suddenness of disasters and the urgency of emergency rescue, combined with the impact of secondary disasters, it is often impossible to obtain relevant information accurately during the emergency rescue process, which increases the difficulty for emergency material allocation. One critical issue in such extreme situation is how to formulate a scientific and rational emergency material allocation plan to achieve multi-period effective supply of relief materials, which meets the realistic demand of multi-period allocation of emergency materials for large-scale disasters. In order to form a reasonable material allocation scheme, this paper proposes an optimal decision model for multi-period dynamic allocation of emergency materials based on the suddenness of disasters, the incompleteness of information acquisition and the urgency of emergency rescue. Firstly, the interval number is introduced to describe the fuzzy uncertainty of the supply and demand of emergency materials, and the triangular fuzzy number is introduced to describe the maximum amount of material transportation per period under the condition of limited road network capacity. Secondly, considering the dynamic changes of demand, supply and maximum transportation amount in different emergency periods, a dual-objective model for dynamic allocation of emergency materials is constructed by introducing delay coefficient, aiming at minimizing the total delay time and total system loss. Thirdly, by designing the deterministic transformation method of fuzzy numbers and the objective weighting fuzzy algorithm based on two-dimensional Euclidean distance, the proposed model are solved. A case study based on the Yushu earthquake is carried out to verify the validity and feasibility of the proposed model. The results show that the proposed model can form a multi-period optimal material allocation scheme based on effectively trade-off the delay time and system loss. Attaching importance to time preference coefficient may increase the total system loss, which indicates that the single consideration of time or loss preference coefficient is one-sided. The decision makers should grasp the "degree" of choice and play the mutual promotion role of their combination. Material allocation scheme is based on the preference of decision makers, and considers the vulnerability, importance, urgency of demand at different affected locations in each period, as well as the importance and timeliness of various emergency materials, which is conducive to improving the flexibility and practical applicability of multi-period decision-making.