改进小生境遗传算法在元搜索引擎调度优化中的研究

针对多独立搜索引擎组合调度时查询精度、查询完全度和响应时间不理想等问题，结合元搜索引擎调度特点对多独立搜索引擎组合调度进行动态优化。文中借鉴小生境思想，将小生境技术与遗传算法、相结合，提出了一种多目标组合优化调度的改进小生境遗传算法。该算法使每个个体在其小生境内进行局部寻优操作，保证了群体的多样性，增强了局部搜索能力，抑制了种群的早熟现象。在多个子目标不能同时达到最优时，采用个体综合适应度对各个目标函数的适应度进行加权，来协调优化各搜索引擎的组合，找到搜索引擎组合调度序列的非劣解。仿真实验结果表明该算法提高了元搜索引擎的调度效率，在查询精度和计算速度上均优于常用的查询优化技术。

Research into the Application of Improved Genetic Algorithm Based on Niches in Search Engine Optimization

Based on the inquiry accuracy, inquiry completion and the response time of the combination and operation optimization of the multi-independent research engine, combined with the feature of the research engine operation, the multi-independent research engine is put in to dynamic optimization. Borrowed the thought of niches, an improved niche genetic algorithm of the multi-objective assembled optimized operation is put forward by combining the technology of niches and the genetic algorithm. This algorithm enables each individual to have local optimization-oriented operation ensures the diversity of the group, strengthens the capability of local research and restrains the prematurity. When many subobjects cannot reach optimization at the same time, this algorithm, in use of individual comprehensive sufficiency can enforce weighting each objective function harmonize and optimize each research engine combination in order to fine a good solution to the combination and operation sequence of research engine. Results of the experiments prove that this Algorithm can improve the efficiency of research engine operation and it surpasses the common inquiry technique in the inquiry accuracy and calculation speed.