303 research outputs found

    Modeling views in the layered view model for XML using UML

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    In data engineering, view formalisms are used to provide flexibility to users and user applications by allowing them to extract and elaborate data from the stored data sources. Conversely, since the introduction of Extensible Markup Language (XML), it is fast emerging as the dominant standard for storing, describing, and interchanging data among various web and heterogeneous data sources. In combination with XML Schema, XML provides rich facilities for defining and constraining user-defined data semantics and properties, a feature that is unique to XML. In this context, it is interesting to investigate traditional database features, such as view models and view design techniques for XML. However, traditional view formalisms are strongly coupled to the data language and its syntax, thus it proves to be a difficult task to support views in the case of semi-structured data models. Therefore, in this paper we propose a Layered View Model (LVM) for XML with conceptual and schemata extensions. Here our work is three-fold; first we propose an approach to separate the implementation and conceptual aspects of the views that provides a clear separation of concerns, thus, allowing analysis and design of views to be separated from their implementation. Secondly, we define representations to express and construct these views at the conceptual level. Thirdly, we define a view transformation methodology for XML views in the LVM, which carries out automated transformation to a view schema and a view query expression in an appropriate query language. Also, to validate and apply the LVM concepts, methods and transformations developed, we propose a view-driven application development framework with the flexibility to develop web and database applications for XML, at varying levels of abstraction

    Autonomous Consolidation of Heterogeneous Record-Structured HTML Data in Chameleon

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    While progress has been made in querying digital information contained in XML and HTML documents, success in retrieving information from the so called hidden Web (data behind Web forms) has been modest. There has been a nascent trend of developing autonomous tools for extracting information from the hidden Web. Automatic tools for ontology generation, wrapper generation, Weborm querying, response gathering, etc., have been reported in recent research. This thesis presents a system called Chameleon for automatic querying of and response gathering from the hidden Web. The approach to response gathering is based on automatic table structure identification, since most information repositories of the hidden Web are structured databases, and so the information returned in response to a query will have regularities. Information extraction from the identified record structures is performed based on domain knowledge corresponding to the domain specified in a query. So called domain plug-ins are used to make the dynamically generated wrappers domain-specific, rather than conventionally used document-specific

    Autonomous Consolidation of Heterogeneous Record-Structured HTML Data in Chameleon

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    While progress has been made in querying digital information contained in XML and HTML documents, success in retrieving information from the so called hidden Web (data behind Web forms) has been modest. There has been a nascent trend of developing autonomous tools for extracting information from the hidden Web. Automatic tools for ontology generation, wrapper generation, Weborm querying, response gathering, etc., have been reported in recent research. This thesis presents a system called Chameleon for automatic querying of and response gathering from the hidden Web. The approach to response gathering is based on automatic table structure identification, since most information repositories of the hidden Web are structured databases, and so the information returned in response to a query will have regularities. Information extraction from the identified record structures is performed based on domain knowledge corresponding to the domain specified in a query. So called domain plug-ins are used to make the dynamically generated wrappers domain-specific, rather than conventionally used document-specific

    WAQS : a web-based approximate query system

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    The Web is often viewed as a gigantic database holding vast stores of information and provides ubiquitous accessibility to end-users. Since its inception, the Internet has experienced explosive growth both in the number of users and the amount of content available on it. However, searching for information on the Web has become increasingly difficult. Although query languages have long been part of database management systems, the standard query language being the Structural Query Language is not suitable for the Web content retrieval. In this dissertation, a new technique for document retrieval on the Web is presented. This technique is designed to allow a detailed retrieval and hence reduce the amount of matches returned by typical search engines. The main objective of this technique is to allow the query to be based on not just keywords but also the location of the keywords within the logical structure of a document. In addition, the technique also provides approximate search capabilities based on the notion of Distance and Variable Length Don\u27t Cares. The proposed techniques have been implemented in a system, called Web-Based Approximate Query System, which contains an SQL-like query language called Web-Based Approximate Query Language. Web-Based Approximate Query Language has also been integrated with EnviroDaemon, an environmental domain specific search engine. It provides EnviroDaemon with more detailed searching capabilities than just keyword-based search. Implementation details, technical results and future work are presented in this dissertation

    Finding structure and characteristic of web documents for classification.

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    by Wong, Wai Ching.Thesis (M.Phil.)--Chinese University of Hong Kong, 2000.Includes bibliographical references (leaves 91-94).Abstracts in English and Chinese.Abstract --- p.iiAcknowledgments --- p.vChapter 1 --- Introduction --- p.1Chapter 1.1 --- Semistructured Data --- p.2Chapter 1.2 --- Problem Addressed in the Thesis --- p.4Chapter 1.2.1 --- Labels and Values --- p.4Chapter 1.2.2 --- Discover Labels for the Same Attribute --- p.5Chapter 1.2.3 --- Classifying A Web Page --- p.6Chapter 1.3 --- Organization of the Thesis --- p.8Chapter 2 --- Background --- p.8Chapter 2.1 --- Related Work on Web Data --- p.8Chapter 2.1.1 --- Object Exchange Model (OEM) --- p.9Chapter 2.1.2 --- Schema Extraction --- p.11Chapter 2.1.3 --- Discovering Typical Structure --- p.15Chapter 2.1.4 --- Information Extraction of Web Data --- p.17Chapter 2.2 --- Automatic Text Processing --- p.19Chapter 2.2.1 --- Stopwords Elimination --- p.19Chapter 2.2.2 --- Stemming --- p.20Chapter 3 --- Web Data Definition --- p.22Chapter 3.1 --- Web Page --- p.22Chapter 3.2 --- Problem Description --- p.27Chapter 4 --- Hierarchical Structure --- p.32Chapter 4.1 --- Types of HTML Tags --- p.33Chapter 4.2 --- Tag-tree --- p.36Chapter 4.3 --- Hierarchical Structure Construction --- p.41Chapter 4.4 --- Hierarchical Structure Statistics --- p.50Chapter 5 --- Similar Labels Discovery --- p.53Chapter 5.1 --- Expression of Hierarchical Structure --- p.53Chapter 5.2 --- Labels Discovery Algorithm --- p.55Chapter 5.2.1 --- Phase 1: Remove Non-label Nodes --- p.57Chapter 5.2.2 --- Phase 2: Identify Label Nodes --- p.61Chapter 5.2.3 --- Phase 3: Discover Similar Labels --- p.66Chapter 5.3 --- Performance Evaluation of Labels Discovery Algorithm --- p.76Chapter 5.3.1 --- Phase 1 Results --- p.75Chapter 5.3.2 --- Phase 2 Results --- p.77Chapter 5.3.3 --- Phase 3 Results --- p.81Chapter 5.4 --- Classifying a Web Page --- p.83Chapter 5.4.1 --- Similarity Measurement --- p.84Chapter 5.4.2 --- Performance Evaluation --- p.86Chapter 6 --- Conclusion --- p.8

    Implementation and Web Mounting of the WebOMiner_S Recommendation System

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    The ability to quickly extract information from a large amount of heterogeneous data available on the web from various Business to Consumer (B2C) or Ecommerce stores selling similar products (such as Laptops) for comparative querying and knowledge discovery remains a challenge because different web sites have different structures for their web data and web data are unstructured. For example: Find out the best and cheapest deal for Dell Laptop comparing BestBuy.ca and Amazon.com based on the following specification: Model: Inspiron 15 series, ram: 16gb, processor: i5, Hdd: 1 TB. The “WebOMiner” and “WebOMiner_S” systems perform automatic extraction by first parsing web html source code into a document object model (DOM) tree before using some pattern mining techniques to discover heterogeneous data types (e.g. text, image, links, lists) so that product schemas are extracted and stored in a back-end data warehouse for querying and recommendation. Although a web interface application of this system needs to be developed to make it accessible for to all users on the web.This thesis proposes a Web Recommendation System through Graphical User Interface, which is mounted readily on the web and is accessible to all users. It also performs integration of the web data consisting of all the product features such as Product model name, product description, market price subject to the retailer, etc. retained from the extraction process. Implementation is done using “Java server pages (JSP)” as the GUI designed in HTML, CSS, JavaScript and the framework used for this application is “Spring framework” which forms a bridge between the GUI and the data warehouse. SQL database is implemented to store the extracted product schemas for further integration, querying and knowledge discovery. All the technologies used are compatible with UNIX system for hosting the required application

    A Survey on Region Extractors from Web Documents

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    Extracting information from web documents has become a research area in which new proposals sprout out year after year. This has motivated several researchers to work on surveys that attempt to provide an overall picture of the many existing proposals. Unfortunately, none of these surveys provide a complete picture, because they do not take region extractors into account. These tools are kind of preprocessors, because they help information extractors focus on the regions of a web document that contain relevant information. With the increasing complexity of web documents, region extractors are becoming a must to extract information from many websites. Beyond information extraction, region extractors have also found their way into information retrieval, focused web crawling, topic distillation, adaptive content delivery, mashups, and metasearch engines. In this paper, we survey the existing proposals regarding region extractors and compare them side by side.Ministerio de Educación y Ciencia TIN2007-64119Junta de Andalucía P07-TIC-2602Junta de Andalucía P08- TIC-4100Ministerio de Ciencia e Innovación TIN2008-04718-EMinisterio de Ciencia e Innovación TIN2010-21744Ministerio de Economía, Industria y Competitividad TIN2010-09809-EMinisterio de Ciencia e Innovación TIN2010-10811-EMinisterio de Ciencia e Innovación TIN2010-09988-

    A survey on Data Extraction and Data Duplication Detection

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    Text mining, also known as Intelligent Text Analysis is an important research area. It is very difficult to focus on the most appropriate information due to the high dimensionality of data. Feature Extraction is one of the important techniques in data reduction to discover the most important features. Processing massive amount of data stored in a unstructured form is a challenging task. Several pre-processing methods and algorithms are needed to extract useful features from huge amount of data. Dealing with collection of text documents, it is also very important to filter out duplicate data. Once duplicates are deleted, it is recommended to replace the removed duplicates. This Paper review the literature on duplicate detection and data fusion (remov e and replace duplicates).The survey provides existing text mining techniques to extract relevant features, detect duplicates and to replace the duplicate data to get fine grained knowledge to the user
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