中文摘要：

针对传统Chord物理拓扑和逻辑拓扑不匹配以及空间复杂度导致搜索效率低的问题，结合遗传算法和双向搜索改进算法的优点，提出了一种基于遗传算法的双向搜索Chord算法。该算法结合遗传算法，将拓扑匹配问题看成一个旅行商问题（TSP），利用遗传算法寻找此问题的最优解，然后用得出的最优解构建Chord环，解决物理拓扑和逻辑拓扑不匹配的问题。在此基础上，使用双向查找算法进一步加快查找速度。实验结果表明，该算法在查询路径长度和查找跳数上比传统的Chord算法具有更高的性能。

英文摘要：

In order to address the issue of mismatch between the physical topology and logical topology, as well as the space complexity, which leads to the low efficiency, this paper proposed a Chord bi-directional search algorithm, based on the gene- tic algorithm, combining with the advantages of genetic algorithm and bi-directional routing look-up mechanism. The algorithm combining genetic algorithm regarded the topology matching problem as a traveling salesman problem （TSP）. It used the ge- netic algorithm to find the best solution of the problem, then constructed the Chord ring, which solved the problem of mismatch between physical topology and logical topology. Based on the above, it used the bi-directional routing look-up mechanism to improve the efficiency. The experimental results show that the proposed algorithm is more effective than the conventional Chord-based method on the length of query path and the hop of query.