基于拍卖机制的灾害多主体合作搜救仿真研究

本文通过多主体仿真，用改进后的截断性莱维游走模型（Truncated Lévy walks）对搜索过程进行模拟，研究灾害为"极严重"、"严重"、"普通"三种情景下，搜救队伍之间基于分布式拍卖机制的合作方案对救援效果的影响，以某滑坡灾害频发地区为例进行仿真，结果表明：基于该合作机制的救援方案同比提高伤员相对生存率8.0%-14.5%，伤员救出比例同比提高7.4%-16.7%，各掩埋点平均救援完成时间同比减少25%-26.7%；与知名的F-Max-Sum算法相比，性能并无逊色，并且计算过程复杂度低，更适用于搜救队伍之间的合作；对救援方案的鲁棒性和敏感度分析还表明，搜索半径的变化对救援效率具有显著影响，搜救队伍合作范围的扩大并不会对救援效率有明显影响；掩埋点限定的挖掘时间和游走模型中最大转动角度两个参数都存在最优值，当达到最优值时，可使整体救援效率最高。

Multi-agent Simulation of Search and Rescue in DisasterBased on Auction Mechanism

In this paper, an agent-based environment is established to simulate the search and rescue after disaster. Two types of active agents are included in this model, namely victims and rescue teams. The improved Truncated Lévy walks model was adopted to simulate rescuers' search behaviors, and an auction algorithm was used to imitate the rescuers' cooperation. The victim agents have a property, i.e., survival probability. Without timely rescue, the health condition of a victim could deteriorate continuously, thus the survival probability will decrease with time, and they may be dead as time passes. The rescue teams search victims in the disaster area, and the rescue teams who locate the buried site take on the role of auctioneers. Other rescue teams who are not at work presently within the scope of cooperation take on the role of bidders. The auctioneers will choose some bidders to cooperate with if necessary. In this paper, the disaster mitigation in adisaster-prone area where landslides occurred frequently is taken as the case to evaluate the performance of proposed scheme. The shapefiles of this area are imported in NetLogo, and the path information is considered in the scheme. To verify the effectiveness of the proposed search and rescue scheme, it is simulated in three scenarios, including "fatal", "serious" and "normal". The simulation results indicate that the cooperative rescue plan would improve victims' relative survival rate by 8.0%-14.5%, improve the ratio of rescued victims to all alive victims by 7.4%-16.7%, and decrease the average elapsed time for one site getting rescued by 25%-26.7%. Moreover, our auction-based approach is as good as the well-known algorithm F-Max-Sum in view of the simulation results, and its low-complexity has made it more appropriate for the cooperation among rescue teams in disaster relief than F-Max-Sum. The robustness analysis shows that search radius plays an important role in improving the rescue efficiency, thus investments in equipment could be adjusted to increase search radius, bringing about improvement in rescue efficiency. The scope of cooperation does not have a significant effect on rescue efficiency, but it is necessary to keep the scope of cooperation larger than a threshold, thus the rescue teams' request for cooperation can be satisfied and the rescue efficiency can be maintained at a high level. The sensitivity analysis shows that the two parameters, the time limit for completing rescue operations in one single site and the maximum turning angle for next step, have great influence on rescue efficiency, and there exist optimal value for both of them in consideration of rescue efficiency.