基于属性相关度的Web数据库大小估算方法

提出了一种基于词频统计的方法以估算Web数据库的规模.通过分析Web数据库查询接口中属性之间的相关度来获取某个属性上的一组随机样本;并对该属性分别提交由前k位高频词形成的试探查询以估算Web数据库中记录的总数.通过在几个真实的Web数据库上进行实验验证,说明该方法可以准确地估算出Web数据库的大小.     

基于属性标签的Web数据挖掘

Div+CSS流行于Web页面的布局,在这种布局下,网页中很多数据记录以重复结构的形式聚集在一个层级.提出一种基于属性标签的Web数据提取的方法,构造带有属性标签的DOM树,通过比较属性标签的值挖掘重复模式,制定三个规则排除干扰模式,找到数据域,进而从数据域中提取出数据记录.     

基于重复模式的Web信息抽取

网页中的大量数据记录往往以重复的HTML结构进行有规律的组织,从而形成一致的表现形式。根据这一特征,本文给出一种基于重复模式的Web内容抽取方法。通过使用一种叫做后缀树的数据结构,分析页面结构中所包含的重复模式,进而从模式的实例中抽取出对应的数据记录。     

多Web数据源环境下的重复实体识别方法研究

Web中大量可访问的数据源为人们获取有用的信息带来了极大的便利。作为Web数据源集成的一个必要的步骤,需要将存在于不同数据源表达形式各异的重复Web实体准确地识别出来。在已有的重复实体识别的工作中,主要是在两个数据源之间进行。由于Web数据源数量众多,使得这些方法无法应用于多个Web数据源之间的重复实体识别。针对这个问题提出了一种基于迭代训练的Web重复实体识别方法,可以在较小规模的训练样本上实现在多个Web数据源上的重复实体识别。通过在图书和计算机产品两个不同领域中多个Web数据源上的广泛实验,表明了提出方法的有效性。     

基于重复模式的自动Web信息抽取

互联网上存在很多在线购物网站,抽取这类网站页面里的商品信息可以为电子商务、Web查询提供增值服务。该文针对这类网站提出一种自动的Web信息抽取方法,通过检测网页中的重复模式以及分析主题内容的特征获取网页的主题内容,该方法在抽取过程中不需要人工干预。对10个在线购物网站进行了测试,实验结果表明提出的方法是有效的。     

基于属性标记的专有名词自动识别研究

提出了一种新的基于属性标记的专有名词统一识别方法。其基本思想是:根据专有名词的成词特点,利用标注语料库,设定词语属性作为标准属性重新进行标注,在此语料基础上进行专有名词成词结构、成词环境的实例提取,并采用基于转换的错误驱动方法对提取的实例进行适用规则提取。在提取的实例和规则的基础上进行属性标注,是一种基于转换的错误驱动规则自学习方法与基于实例的学习方法相结合的基于浅层句法分析的一种新的识别专有名词的方法。实验证明该方法在测试样本集上准确率达到95.3%,召回率达到92.5%,是一种有效的专有名词识别方法。     

基于N-Gram的Deep Web接口属性抽取

Deep Web中,查询接口属性的抽取是Deep Web数据集成中必不可少的一个环节。本文通过将接口属性中文文本翻译成为汉语拼音和英文,利用N-Gram方法完成中文查询接口中属性的抽取。经过多个领域的查询接口的实验,证明该方法能有效地抽取出查询接口的属性。     

基于属性标记的专有名词自动识别研究

提出了一种新的基于属性标记的专有名词统一识别方法。其基本思想是：根据专有名词的成词特点，利用标注语料库，设定词语属性作为标准属性重新进行标注，在此语料基础上进行专有名词成词结构、成词环境的实例提取．并采用基于转换的错误驱动方法对提取的实例进行适用规则提取，在提取的实例和规则的基础上进行属性标注，是一种基于转换的错误驱动规则自学习方法与基于实例的学习方法相结合的基于浅层句法分析的一种新的识别专有名词的方法。实验证明该方法在测试样本集上准确率达到95．3％．召回率达到92．5％．是一种有效的专有名词识别方法。     

基于属性证书的Web Services访问控制模型

Web Services的安全性已成为Web Services广泛应用的主要障碍,Web Services需要解决的安全问题包括：机密性,完整性,抗抵赖性,身份认证,授权和访问控制等。该文针对Web Services的授权和访问控制中存在的问题,提出了一种基于属性证书的Web Services授权机制并分析了利用属性证书实现Web Services角色访问控制的特点。     

基于重复模式的Web信息语义表示方法的研究

根据Web页面中出现的重复信息对Web页所体现的语义进行表示,可以提高Web页分类正确的精度.基于这一思想,本文通过对传统重复模式表示法的分析,提出基于重复模式的Web信息语义表示法.该方法在形式化描述重复模式的基础上,抽取Web信息中的重复模式建立表达Web信息语义特征的相关矩阵,并通过γ相似匹配算法计算重复模式的权重继而进行Web信息分类.实验证明,采用基于重复模式的Web信息语义表示法能够较好的体现Web网页信息的主题特征,可以提高Web信息分类的准确率.     

Automatic Web-based relational data imputation

Data incompleteness is one of the most important data quality problems in enterprise information systems. Most existing data imputing techniques just deduce approximate values for the incomplete attributes by means of some specific data quality rules or some mathematical methods. Unfortunately, approximation may be far away from the truth. Furthermore, when observed data is inadequate, they will not work well. The World Wide Web (WWW) has become the most important and the most widely used information source. Several current works have proven that using Web data can augment the quality of databases. In this paper, we propose a Web-based relational data imputing framework, which tries to automatically retrieve real values from the WWW for the incomplete attributes. In the paper, we try to take full advantage of relations among different kinds of objects based on the idea that the same kind of things must have the same kind of relations with their relatives in a specific world. Our proposed techniques consist of two automatic query formulation algorithms and one graph-based candidates extraction model. Several evaluations are proposed on two high-quality real datasets and one poor-quality real dataset to prove the effectiveness of our approaches.     

Conflict resolution in a knowledge-based system using multiple attribute decision-making

The metarules useful in the conflict resolution are often directly related to the multiple, conflicting, and non-commensurate objectives associated with the problem domain. However, in its current form, the use of metarules for conflict resolution has some drawbacks. Above all, the metarule use in rule selection is not tailored to the current situation or the specific user; it is tailored to the domain expert, whose domain expertise and preferences were used to construct a knowledge-based system. In this paper, we presents a new method for resolving the conflicts of rules in the knowledge-based system, using decision analysis techniques that explicitly incorporate a user’s preference judgments about the rules. To this end, we consider a conflict resolution problem as a multiple attribute decision-making problem. Further, the proposed method allows for user’s preference judgments that are specified not by rigid format but by user-friendly format for the purpose of reducing burden of information specification.We have applied the proposed methodology to an organizational information-oriented service and resource planning, in which there exist multiple conflicting objectives to be considered.     

A personalized search engine based on Web‐snippet hierarchical clustering

We propose a (meta‐)search engine, called SnakeT (SNippet Aggregation for Knowledge ExtracTion), which queries more than 18 commodity search engines and offers two complementary views on their returned results. One is the classical flat‐ranked list, the other consists of a hierarchical organization of these results into folders created on‐the‐fly at query time and labeled with intelligible sentences that capture the themes of the results contained in them. Users can browse this hierarchy with various goals: knowledge extraction, query refinement and personalization of search results. In this novel form of personalization, the user is requested to interact with the hierarchy by selecting the folders whose labels (themes) best fit her query needs. SnakeT then personalizes on‐the‐fly the original ranked list by filtering out those results that do not belong to the selected folders. Consequently, this form of personalization is carried out by the users themselves and thus results fully adaptive, privacy preserving, scalable and non‐intrusive for the underlying search engines. We have extensively tested SnakeT and compared it against the best available Web‐snippet clustering engines. SnakeT is efficient and effective, and shows that a mutual reinforcement relationship between ranking and Web‐snippet clustering does exist. In fact, the better the ranking of the underlying search engines, the more relevant the results from which SnakeT distills the hierarchy of labeled folders, and hence the more useful this hierarchy is to the user. Vice versa, the more intelligible the folder hierarchy, the more effective the personalization offered by SnakeT on the ranking of the query results. Copyright © 2007 John Wiley & Sons, Ltd.     

基于属性重要性的粗糙集属性约简方法

信息系统中的属性约简是粗糙集知识发现的一个重要步骤。致力于研究一个信息系统中的特征选择、删除冗余属性。新的算法从属性重要性出发,采用迭代特征选择的标准,使得选择特征属性集不断缩小,获得信息系统的约简。通过实验证明该方法可行,有效。     

基于网络搜索引擎的网络话题分析框架

为了解网络话题内容组成和演化情况,提出基于有向图的在线分类（OCBDG）方法,并设计一个基于网络搜索引擎的话题分析框架。通过搜索引擎查询话题内容,OCBDG将查询结果分成若干子话题,分析子话题间的关系和演变。结果证明,该方法能够以大约70％的正确率分析出子话题,并能准确、及时地反映话题在网络上任意时间跨度的变化情况。     

一种新的属性分类方法与应用刍议

以形式化语言给出了本质属性、附属属性、限定性属性等术语的定义,研究了它们的性质与内在联系,给出了属性集的一种新的分类方法。结合对属性子集的一种新运算,特别讨论了本质属性的特征,并以此对IDEF5中种类的概念做了形式化修正。同时,研究发现,在本质属性为多个时,只需保留一条,其他任何一条本质属性既是可约属性也是不必要属性,而本质属性的判定简便易行,在利用相关算法进行属性约简之前可以先剔除部分属性。最后,以实例表明了这样预处理的优越性。     

Rabin指纹去重算法在搜索引擎中的应用

针对搜索引擎在海量数据中搜索速度慢,占用存储空间大,对重复的网页去重性差的现状,提出一种基于Rabin指纹算法的去重方法,不仅对搜索到的URL地址进行去重,还对非重复URL地址对应的网页内容进行相似和相同的去重,试验表明能有效地提高搜索速度、节省存储空间,增强搜索的精度。     

Mining Web search engines for query suggestion

Queries to Web search engines are usually short and ambiguous, which provides insufficient information needs of users for effectively retrieving relevant Web pages. To address this problem, query suggestion is implemented by most search engines. However, existing methods do not leverage the contradiction between accuracy and computation complexity appropriately (e.g. Google's ‘Search related to’ and Yahoo's ‘Also Try’). In this paper, the recommended words are extracted from the search results of the query, which guarantees the real time of query suggestion properly. A scheme for ranking words based on semantic similarity presents a list of words as the query suggestion results, which ensures the accuracy of query suggestion. Moreover, the experimental results show that the proposed method significantly improves the quality of query suggestion over some popular Web search engines (e.g. Google and Yahoo). Finally, an offline experiment that compares the accuracy of snippets in capturing the number of words in a document is performed, which increases the confidence of the method proposed by the paper. Copyright © 2010 John Wiley & Sons, Ltd.     

三支决策视角下的属性约简加速方法

Attribution reduction is one of the key topics in the field of rough set theory. Based on such theory, the concept of ensemble attribute reduction has been proposed. The ensemble reduction is to divide the sample into multiple decision systems in terms of the decision categories and then calculate them separately. Although ensemble attribute reduction balances the requirements of various decision classes, the corresponding time of attribute reduction is increased. To solve this problem, an attribute reduction acceleration method based on sequential three-way decisions is proposed. The specific steps are as follows: (1) The importance of the attribute in the decision system is calculated. (2) The attributes are divided into three groups in terms of the significance degree of corresponding attribute. Then, the attributes with maximal significance degree are classified into the positive domain, the attributes with zero significance degree are classified into the negative domain, and other attributes will be classified into the boundary domain. (3) The significance degree of the attributes in the boundary domain is calculated cyclically and the obtained result is divided, until theconstraint is satisfied. 8 UCI data sets are selected to conduct experiments in the traditional attribute reduction and ensemble reduction environments, respectively. The experimental results show that, under the premise of ensuring the classification performance, the proposed method can effectively reduce the time of attribute reduction in such two environments.     

面向相似重复记录检测的特征优选方法

大数据集相似重复记录检测和识别中,数据源组成复杂、表征数据记录的特征属性过多,因而检测精度不高、执行检测的代价过大.针对这些问题,提出了一种分组模糊聚类的特征优选方法.首先进行分组记录的属性处理,以有效降低记录属性的维数,并获得分组中的代表性记录,然后采用一种相似度比较计算方法进行组内相似重复记录的检测.理论分析和实验...