Minimum Cost of Capacity Expansion for Time-Limited Transportation Problem On-Demand

The minimum cost of capacity expansion for time-limited transportation problem on-demand (MCCETLTPD) is to find such a practicable capacity expansion transportation scheme satisfying the time-limited T along with all origins’ supply and all destinations’ demands as well as the expanding cost is minimum. Actually, MCCETLTPD is a balance transportation problem and a variant problem of minimum cost maximum flow problem. In this paper, by creating a mathematical model and constructing a network with lower and upper arc capacities, MCCETLTPD is transformed into searching feasible flow in the constructed network, and consequently, an algorithm MCCETLTPD-A is developed as MCCETLTPD’s solution method basing minimum cost maximum flow algorithm. Computational study validates that the MCCETLTPD-A algorithm is an efficient approach to solving the MCCETLTPD.

有上下界网络最大流与最小截问题

为了便于建立与有上下界网络最大流与最小截问题有关的决策支持系统,本文给出一个求有上下界网络最大流与最小截的数值算法,证明了算法的理论依据,并举例说明了算法在堵塞流理论中的应用。该算法能判定问题是否有可行解,在问题有可行解的情况下能求得问题的最优解。该算法具有易于编程实现、收敛性好等优点。数值实验表明该算法有较高的计算效率,可用于求解最小饱和流问题。

基于欠载失效的供应链网络级联失效建模

鉴于直接采用基础设施网络中的过载级联失效模型研究供应链网络中的欠载级联失效现象存在不足,从企业欠载失效、企业负载容量具有上下限和负载按照企业间的业务关系强度重分配3方面出发,提出一个更加适合供应链网络的级联失效模型。利用Erdos-Renyi网络模型和Barabasi-Albert网络模型构建了供应链网络,在随机攻击和蓄意攻击模式下验证了模型的有效性,同时研究了模型中的各参数对级联失效的影响。结果表明,负载可调参数θ和关系强度参数τ存在一个最优取值区间,使得网络对级联失效表现出强鲁棒性;容量上限参数δ与级联失效规模负相关;容量下限参数σ与级联失效规模正相关。