论文标题
广义随机匹配
Generalized Stochastic Matching
论文作者
论文摘要
在本文中,我们将最近研究的随机匹配问题推广,以更准确地对重要的医疗过程,肾脏交换和其他几种应用进行建模。到目前为止,已经研究的随机匹配问题如下:给定图G =(v,e),每个边缘都包含在g相互实现的g相互独立的概率p_e中,并且目标是找到具有学位的G的G Q Q,它具有预期的最大匹配,以近似于实现的最大匹配现实的子图。该模型无法解释顶点辍学的可能性,这可以在几种应用中找到,例如在肾脏交换中,当发现在线概况时,捐助者或患者选择退出交换过程以及在线自由职业和在线约会。因此,我们将研究一个更具概括的随机匹配模型,在该模型中,顶点和边缘分别与某些概率P_V,P_E独立实现,该模型比以前研究的模型更准确地适合重要应用。 我们将讨论对随机匹配模型的概括的第一种算法和分析,并证明它们达到良好的近似比。特别是,我们表明,此问题的天然算法的近似因素至少为$ 0.6568 $未加权的图,而加权图的$ 1/2 +ε$,对于某些常数$ε> 0 $。我们使用边缘学位约束子图(EDC)进一步将未加权图的结果提高到$ 2/3 $。
In this paper, we generalize the recently studied Stochastic Matching problem to more accurately model a significant medical process, kidney exchange, and several other applications. Up until now the Stochastic Matching problem that has been studied was as follows: given a graph G = (V, E), each edge is included in the realized sub-graph of G mutually independently with probability p_e, and the goal is to find a degree-bounded sub-graph Q of G that has an expected maximum matching that approximates the expected maximum matching of the realized sub-graph. This model does not account for possibilities of vertex dropouts, which can be found in several applications, e.g. in kidney exchange when donors or patients opt out of the exchange process as well as in online freelancing and online dating when online profiles are found to be faked. Thus, we will study a more generalized model of Stochastic Matching in which vertices and edges are both realized independently with some probabilities p_v, p_e, respectively, which more accurately fits important applications than the previously studied model. We will discuss the first algorithms and analysis for this generalization of the Stochastic Matching model and prove that they achieve good approximation ratios. In particular, we show that the approximation factor of a natural algorithm for this problem is at least $0.6568$ in unweighted graphs, and $1/2 + ε$ in weighted graphs for some constant $ε> 0$. We further improve our result for unweighted graphs to $2/3$ using edge degree constrained subgraphs (EDCS).