基于分块重要度和二维条件随机场的Web信息抽取  

Web Information extraction based on block importance model and 2D conditional random fields

作　　者：吴秦[1] 胡丽娟[1] 梁久祯[1] 

机构地区：[1]江南大学物联网工程学院,无锡214122

出　　处：《南京大学学报（自然科学版）》2014年第1期79-86,共8页Journal of Nanjing University（Natural Science）

基　　金：国家自然科学基金(61202312;61170121)

摘　　要：网页分块方法使得Web信息抽取的单位由原来的页面缩小为分块.结合分块重要度模型与二维条件随机场的优点,提出一种Web对象信息抽取方法.该方法利用分块重要度模型对网页分块进行重要度标注,过滤掉大量与主题无关信息,更加准确的定位待抽取信息的位置.二维条件随机场模型相比传统的线性条件随机场模型更好的适应了网页分块的二维结构,有效的提高信息抽取准确率.实验结果表明,该方法对Web对象信息抽取具有良好的效果.Uncertainty is a major and important property in the study of time series data mining under the background of multi-granular research.It is found that the instability of temporal granularity itself is a widespread phenomenon, but due to the variability of granularity,it is a non-trivial task to develop feasible solutions.As a result,few papers report efficient idea for this problem.To describe it systematically,a basic model of the uncertain multi-granularity time series with related basic definition is proposed initially.Based on the above theory,the reason of uncertain time series granularity is analyzed,and a strategy of stabling time granularity algorithm is then proposed.Finally,an optimal strategy of granularity selection for multi-granularity time series and a tactic for decreasing the variability of uncertain granularity are studied and discussed respectively.Uncertain multi-granularity time series data clustering requires cluster analysis since it is a fundamental job for further process such as prediction and analysis in time-series＆amp;nbsp;data,but due to the complexity,it becomes a special challenging.We introduce a stable temporal granularity clustering algorithm framework to solve the uncertain time series data clustering problem.An Intensive Care Unit Survival prediction experiment with the property of uncertainty in temporal granularity is conducted to verify the above theory.Results show that different choices of time granularity produces different outcome which is in line with the computational law of granular computing,and stable strategy for granularity can achieve satisfied prediction.

关 键 词：WEB对象 信息抽取 网页分块 分块重要度模型 二维条件随机场 

分 类 号：TP392[自动化与计算机技术—计算机应用技术]