The World Wide Web has become one of the most important connections to various sources of information. A large proportion of the data is embedded in HTML documents. This language serves the visual presentation of data in Internet browser, but does not provide semantic information for the data presented. This form of data presentation is, therefore, inappropriate for the demands of automated, co...

In this paper, we focus on the problem in information integration system of obtaining data from heterogeneous data source accurately and effectively. XML is used as data exchange format of the wrapper. We design the wrapper architecture based on the conversion and management of the views as the bridge from global schema to local schema of various data sources. Our wrapper has two main subsystem...

different approaches have been proposed for feature selection to obtain suitable features subset among all features. these methods search feature space for feature subsets which satisfies some criteria or optimizes several objective functions. the objective functions are divided into two main groups: filter and wrapper methods.  in filter methods, features subsets are selected due to some measu...

Recently, several wrapper induction algorithms for structured documents have been introduced. They are based on contextual tree languages and learn from positive examples only but have the disadvantage that they need parameters. To obtain the optimal parameter setting, they use precision and recall. This goes in fact beyond learning from positive examples only. In this paper, a parameter estima...

With Ihe growth of digital libraries and electronic publishing, many structured document sources are appearing and their efleclive mediation is an imporlanl research topic. In this paper, we propose a wrapping architecture for externally maintained struclured document sources. Our wrapping target is information retrieval systems (IRSs) that provide access to strucaured documenk We describe a wr...

Many Internet information resources present relational data|telephone directories, product catalogs, etc. Because these sites are formatted for people, mechanically extracting their content is di cult. Systems using such resources typically use hand-coded wrappers, procedures to extract data from information resources. We introduce wrapper induction, a method for automatically constructing wrap...

Web scraping (or wrapping) is a popular means for acquiring data from the web. Recent advancements have made scalable wrapper-generation possible and enabled data acquisition processes involving thousands of sources. This makes wrapper analysis and maintenance both needed and challenging as no scalable tools exists that support these tasks. We demonstrate WADaR, a scalable and highly automated ...