案例推理变权值引擎模型及权值计算方法

在案例推理（CBR）案例检索匹配中，不同案例通常由不同的特征构成。而传统的CBR引擎模型大多采用固定权值模式，导致系统在匹配精度方面的性能很低。为了解决这一问题，提出一种CBR变权值引擎模型，在其特征权值计算模块引入人机互动机制，基于群决策法计算主观权值，提出依据专家个体和群体决策差异的主观权值调整方法；基于相似粗糙集法计算客观权值。最后设计了一种综合权值调整算法，通过计算主观权值和客观权值间的距离，判断两者的偏离程度，从而推导出权值调整系数，得到最终的权值调整结果。通过网络攻击案例进行的算例分析和仿真实验验证了上述方法的正确性和优越性。

Case-based reasoning engine model with variable feature weights and its calculation method

In the Case-Based Reasoning (CBR) case retrieving and matching, different cases are usually composed by different features. But most of the traditional CBR engines adopt fixed feature weights mode, which makes matching rate of whole system very low. To solve this problem, this paper proposed a CBR engine model with variable feature weights and brought interactive mode into feature weights calculating module. It calculated subjective weight based on group decision making theory and proposed an adjustment method which used differences between a single expert and his group. It used similarity rough set theory to calculate objective weight in order to make results calculating more objective and accurate. At last, it designed composite weights adjustment algorithm which calculated the distance between the subjective weight and objective weight, considered the deviation degree of those two weights, then deduced weights adjustment coefficient, and get the final weight adjustment results. The calculation example and simulation analysis of network attack cases validate the effectiveness of the proposed method and prove this method has much better performance in different performance indexes.