Applying semantic web technologies to knowledge sharing in aerospace engineering

This paper details an integrated methodology to optimise Knowledge reuse and sharing, illustrated with a use case in the aeronautics domain. It uses Ontologies as a central modelling strategy for the Capture of Knowledge from legacy docu-ments via automated means, or directly in systems interfacing with Knowledge workers, via user-defined, web-based forms. The domain ontologies used for Knowledge Capture also guide the retrieval of the Knowledge extracted from the data using a Semantic Search System that provides support for multiple modalities during search. This approach has been applied and evaluated successfully within the aerospace domain, and is currently being extended for use in other domains on an increasingly large scale

The Syllabus Based Web Content Extractor (SBWCE)

Syllabus Based Web Content Extractor (SBWCE) introduces a new technique of Syllabus Based Web Content Mining. It makes the Syllabus Based Web Content Extraction easy and creates an instant online book view based on the links relevant to the given Syllabus. Three important contributions are made by the current work. First, as multiple format educational information is needed for Syllabus based content; the technique used makes the finding of such content easier. Second, a new approach for capturing and recording the heuristics involved during searching by experts is used. Third, the grouping of Syllabus Words for precise extraction is exploited. This paper introduces SBWCE and presents the related details

Template-Based Metadata Extraction for Heterogeneous Collection

With the growth of the Internet and related tools, there has been a rapid growth of online resources. In particular, by using high-quality OCR (Optical Character Recognition) tools it has become easy to convert an existing corpus into digital form and make it available online. However, a number of organizations have legacy collections that lack metadata. The lack of metadata hampers not only the discovery and dispersion of these collections over the Web, but also their interoperability with other collections. Unfortunately, manual metadata creation is expensive and time-consuming for a large collection, and most existing automated metadata extraction approaches have focused on specific domains and homogeneous collections. Developing an approach to extract metadata automatically from a large number of challenges. In particular, the heterogeneous legacy collection poses a following issues need to be addressed: (1) Heterogeneity, i.e. how to achieve a high accuracy for a heterogeneous collection; (2) Scaling, i.e. how to apply an automated metadata extraction approach to a very large collection; (3) Evolution, i.e. how to process new documents added to a collection over time; (4) Adaptability, i.e. how to apply an approach to a new document collection; (5) Complexity, i.e. how many document features can be handled, and how complex the features should be. In this dissertation, we propose a template-based metadata extraction approach to address these issues. The key idea of addressing the heterogeneity is to classify documents into equivalent groups so that each document group contains similar documents only. Next, for each document group we create a template that contains a set of rules to instruct a template engine how to extract metadata from documents in the group. Templates are written in an XML-based language and kept in separate files. Our approach of decoupling rules from programming codes and representing them in a XML format is easy to adapt to another collection with documents in different styles. We developed our test bed by downloading about 10,000 documents from DTIC (Defense Technical Information Center) document collection that consists of scanned versions of documents in PDF (Portable Document Format) format. We have evaluated our approach on the test bed consisting of documents from DTIC collection, and our results are encouraging. We have also demonstrated how the extracted metadata can be utilized to integrate our test bed with an interoperable digital library framework based on OAI (Open Archives Initiative)

Bridging the gap between closed and open data. System proposal for the Portuguese Legislation

Esta dissertação apresenta uma proposta de sistema capaz de preencher a lacuna entre documentos legislativos em formato PDF e documentos legislativos em formato aberto. O objetivo principal é mapear o conhecimento presente nesses documentos de maneira a representar essa coleção como informação interligada. O sistema é composto por vários componentes responsáveis pela execução de três fases propostas: extração de dados, organização de conhecimento, acesso à informação. A primeira fase propõe uma abordagem à extração de estrutura, texto e entidades de documentos PDF de maneira a obter a informação desejada, de acordo com a parametrização do utilizador. Esta abordagem usa dois métodos de extração diferentes, de acordo com as duas fases de processamento de documentos – análise de documento e compreensão de documento. O critério utilizado para agrupar objetos de texto é a fonte usada nos objetos de texto de acordo com a sua definição no código de fonte (Content Stream) do PDF. A abordagem está dividida em três partes: análise de documento, compreensão de documento e conjunção. A primeira parte da abordagem trata da extração de segmentos de texto, adotando uma abordagem geométrica. O resultado é uma lista de linhas do texto do documento; a segunda parte trata de agrupar os objetos de texto de acordo com o critério estipulado, produzindo um documento XML com o resultado dessa extração; a terceira e última fase junta os resultados das duas fases anteriores e aplica regras estruturais e lógicas no sentido de obter o documento XML final. A segunda fase propõe uma ontologia no domínio legal capaz de organizar a informação extraída pelo processo de extração da primeira fase. Também é responsável pelo processo de indexação do texto dos documentos. A ontologia proposta apresenta três características: pequena, interoperável e partilhável. A primeira característica está relacionada com o facto da ontologia não estar focada na descrição pormenorizada dos conceitos presentes, propondo uma descrição mais abstrata das entidades presentes; a segunda característica é incorporada devido à necessidade de interoperabilidade com outras ontologias do domínio legal, mas também com as ontologias padrão que são utilizadas geralmente; a terceira característica é definida no sentido de permitir que o conhecimento traduzido, segundo a ontologia proposta, seja independente de vários fatores, tais como o país, a língua ou a jurisdição. A terceira fase corresponde a uma resposta à questão do acesso e reutilização do conhecimento por utilizadores externos ao sistema através do desenvolvimento dum Web Service. Este componente permite o acesso à informação através da disponibilização de um grupo de recursos disponíveis a atores externos que desejem aceder à informação. O Web Service desenvolvido utiliza a arquitetura REST. Uma aplicação móvel Android também foi desenvolvida de maneira a providenciar visualizações dos pedidos de informação. O resultado final é então o desenvolvimento de um sistema capaz de transformar coleções de documentos em formato PDF para coleções em formato aberto de maneira a permitir o acesso e reutilização por outros utilizadores. Este sistema responde diretamente às questões da comunidade de dados abertos e de Governos, que possuem muitas coleções deste tipo, para as quais não existe a capacidade de raciocinar sobre a informação contida, e transformá-la em dados que os cidadãos e os profissionais possam visualizar e utilizar.This dissertation presents a system proposal capable of bridging the gap between legal documents in PDF format and open legislative documents. The objective is mainly to map the knowledge present in these documents in order to represent the collection as linked information. The system contains various components responsible for the execution of three proposed phases of execution: data extraction, knowledge organization and information access. The first phase proposes an approach to extract structure, text and entities from PDF documents in order to obtain the desired information in accordance with the user parameterization. The second phase proposes a legal domain ontology in order to organize the information extracted from the extraction process of the first phase and is also responsible for the indexing process of the legislative text of the documents. The third phase provides an answer to the access and reuse of the knowledge by third parties through the development of a Web Service. Additionally, an Android Mobile Application was developed to provide visualizations of the information requests. The desired final outcome is thus the development of a system that transforms collections of PDF documents to open data format collections in a way that it should become accessible and reusable by third parties

Structural extraction from visual layout of documents

Most information extraction systems focus on the textual content of the documents. They treat documents as sequences of words, disregarding the physical and typographical layout of the information. While this strategy helps in focusing the extraction process on the key semantic content of the document, much valuable information can also be derived form the document physical appearance. Often, fonts, physical positioning and other graphical characteristics are used to provide additional context to the information. This information is lost with pure-text analysis. In this paper we describe a general procedure for structural extraction, which allows for automatic extraction of entities from the document based on their visual characteristics and relative position in the document layout. Our structural extraction procedure is a learning algorithm, which automatically generalizes from examples. The procedure is a general one, applicable to any document format with visual and typographical information. We also describe a specific implementation of the procedure to PDF documents, called PES (PDF Extraction System). PES works with PDF documents and is able to extract fields such a