基于相关性反馈的自适应热点话题追踪模型  

Adaptive hot topic tracking model based on relevance feedback

作　　者：翟东海[1,2] 鱼江[1] 聂洪玉[1] 崔静静[1] 杜佳[1] 

机构地区：[1]西南交通大学信息科学与技术学院,四川成都610031 [2]西藏大学工学院,西藏拉萨850000

出　　处：《山东大学学报（工学版）》2014年第1期7-12,共6页Journal of Shandong University（Engineering Science）

基　　金：国家语委"十二五"科研规划资助项目(YB125-49);教育部科学技术研究重点资助项目(212167);中央高校基本科研业务费专项资金科技创新资助项目(SWJTU12CX096)

摘　　要：针对在热点话题追踪过程中容易发生话题漂移的问题,提出了基于相关性反馈的自适应热点话题追踪模型。为准确把握话题的动态演变过程,首先,在词频-逆向文档频率(term frequency—inverse document frequency,TF-IDF)的基础上引入了相关度因子。其次,构造了报道与话题的相关度计算公式和新特征词能否反馈加入到话题词汇库的判别函数。同时,利用了话题词汇库本身的特性,构造了自适应更新阈值和自适应相关阈值的动态计算方法。最后,根据各个特征词对该话题贡献度的大小,对更新后的词汇库中的各特征词动态赋予新权重。实验结果显示,和其它3类追踪器相比,该追踪器模型的漏报率平均降低0.018、误报率平均降低0.063,这表明,该追踪模型更适合于解决话题漂移问题。To solve the topic excursion problem in hot topic tracking process, an adaptive hot topic tracking model based on relevance feedback was proposed.To obtain the topic dynamic evolution procedure accurately, firstly, a corre-lation factor was introduced into TF-IDF （ term frequency-inverse document frequency） for extracting feature words. Secondly, a formula for computing relevance degree between story and topic was constructed, and a discriminant func-tion for determining whether the new feature word could be added into the topic lexicon was also constructed.At the same time, the methods for dynamically computing adaptive updating threshold and adaptive correlation threshold were given.Finally, in the updated topic lexicon, our approach gave the new weight to each feature word according to its contribution to the topic.The experimental results showed that the proposed method could reduce the false alarm rate 0.018 and the miss alarm rate 0.063 compared with the other 3 trackers in the hot topic tracking process, which conclu-ded that this proposed technique was more suitable for solving the problem of topic drift.

关 键 词：话题追踪 话题漂移 相关性反馈 自适应阈值 权重更新 

分 类 号：TP301.6[自动化与计算机技术—计算机系统结构]