Página 1 dos resultados de 336 itens digitais encontrados em 0.017 segundos

The construction of a juridical ontology

Alves, Isa Mara da Rosa; Chishman, Rove Luiza de Oliveira; Torres, Paulo Miguel; Quaresma, Duarte
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Conferência ou Objeto de Conferência Formato: 93-94
Português
Relevância na Pesquisa
59.13781%
The need for the representation of both semantics and common sense and its organization in a lexical database or knowledge base has motivated the development of large projects, such as Wordnets, CYC and Mikrokosmos. Besides the generic bases, another approach is the construction of ontologies for specific domains. Among the advantages of such approach there is the possibility of a greater and more detailed coverage of a specific domain and its terminology. Domain ontologies are important resources in several tasks related to the language processing, especially in those related to information retrieval and extraction in textual bases. Information retrieval or even question and answer systems can benefit from the domain knowledge represented in an ontology. Besides embracing the terminology of the field, the ontology makes the relationships among the terms explicit. Copyright 2007 ACM.

Modelo fuzzy para recuperação de informação utilizando multiplas ontologias relacionadas; Fuzzy information retrieval model using multiple related ontologies

Maria Angelica de Andrade Leite
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 13/03/2009 Português
Relevância na Pesquisa
68.988516%
Com a crescente popularidade da World Wide Web mais pessoas têm acesso à informação cujo volume vem expandindo ao longo do tempo. A área de recuperação de informação ganhou um novo desafio visando buscar os recursos pelo significado da informação neles contida. Uma forma de recuperar a informação, pelo seu significado, é pelo uso de uma base de conhecimento que modela os conceitos de um domínio e seus relacionamentos. Atualmente, ontologias têm sido utilizadas para modelar bases de conhecimento. Para tratar com a imprecisão e a incerteza, presentes no conhecimento e no processo de recuperação de informação, são empregadas técnicas da teoria de conjuntos fuzzy. Trabalhos precedentes codificam a base de conhecimento utilizando apenas uma ontologia. Entretanto, uma coleção de documentos pode tratar temas pertencentes a domínios diferentes, expressos por ontologias distintas, que podem estar relacionados. Neste trabalho, uma forma de organização e representação do conhecimento em múltiplas ontologias relacionadas foi investigada e um novo método de expansão de consulta foi desenvolvido. A organização do conhecimento e o método de expansão de consulta foram integrados no modelo fuzzy para recuperação de informação utilizando múltiplas ontologias relacionadas. O desempenho do modelo foi comparado com outro modelo fuzzy para recuperação de informação e com a máquina de busca Lucene do projeto Apache. Em ambos os casos o modelo proposto apresentou uma melhora nas medidas de precisão e cobertura; With the World Wide Web popularity growth...

A methodology to create ontology-based information retrieval systems

Saias, José; Quaresma, Paulo
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
68.56579%
Modern information retrieval systems need the capability to reason about the knowledge conveyed by text bases. In this paper a methodology to automatically create ontologies and class instances from documents is proposed. The ontology is defined in the OWL semantic web language and it is used by a logic programming framework, ISCO, to allow users to query the semantic content of the documents. ISCO allows an easy and efficient integration of declarative, object-oriented and constraint-based programming techniques with the capability to create connections with external databases.

Enhancing information retrieval in folksonomies using ontology of place constructed from Gazetteer information

Sabrah, Rania Abd El Fattah Ahmed
Fonte: Universidade Nova de Lisboa Publicador: Universidade Nova de Lisboa
Tipo: Dissertação de Mestrado
Publicado em 09/03/2009 Português
Relevância na Pesquisa
59.254434%
Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial Technologies; Folksonomy (from folk and taxonomy) is an approach to user metadata creation where users describe information objects with a free-form list of keywords (‘tags’). Folksonomy has have proved to be a useful information retrieval tool that support the emergence of “collective intelligence” or “bottom-up” light weight semantics. Since there are no guiding rules or restrictions on the users, folksonomy has some drawbacks and problems as lack of hierarchy, synonym control, and semantic precision. This research aims at enhancing information retrieval in folksonomy, particularly that of location information, by establishing explicit relationships between place name tags. To accomplish this, an automated approach is developed. The approach starts by retrieving tags from Flickr. The tags are then filtered to identify those that represent place names. Next, the gazetteer service that is a knowledge organization system for spatial information is used to query for the place names. The result of the search from the gazetteer and the feature types are used to construct an ontology of place. The ontology of place is formalized from place name concepts...

An information retrieval application using ontologies

Paz-Trillo,Christian; Wassermann,Renata; Braga,Paula P.
Fonte: Sociedade Brasileira de Computação Publicador: Sociedade Brasileira de Computação
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2005 Português
Relevância na Pesquisa
68.93207%
Searching for information in long videos can be a time-consuming experience. In this paper, we describe OnAIR, an ontology-aided information retrieval system applied to retrieve clips from video collections. We used a video collection compiled from interviews with Ana Teixeira, a Brazilian artist. The interviews were made by Paula P. Braga, the domain expert. The interview is developed in the domain of contemporary art and the system uses a domain ontology to expand the queries with related terms. We tested the system with a battery of queries, and we veri.ed that the ontology contributes to the e.ciency improvement in terms of the relevance of retrieved documents. We designed the system to work in a domain-independent way, allowing us to move to other domains by just changing the underlying ontologies and video collections.

A Qualitative Representation and Similarity Measurement Method in Geographic Information Retrieval

Gao, Yong; Liu, Lei; Lin, Xing; Liu, Yu
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 19/11/2013 Português
Relevância na Pesquisa
69.005137%
The modern geographic information retrieval technology is based on quantitative models and methods. The semantic information in web documents and queries cannot be effectively represented, leading to information lost or misunderstanding so that the results are either unreliable or inconsistent. A new qualitative approach is thus proposed for supporting geographic information retrieval based on qualitative representation, semantic matching, and qualitative reasoning. A qualitative representation model and the corresponding similarity measurement method are defined. Information in documents and user queries are represented using propositional logic, which considers the thematic and geographic semantics synthetically. Thematic information is represented as thematic propositions on the base of domain ontology. Similarly, spatial information is represented as geo-spatial propositions with the support of geographic knowledge base. Then the similarity is divided into thematic similarity and spatial similarity. The former is calculated by the weighted distance of proposition keywords in the domain ontology, and the latter similarity is further divided into conceptual similarity and spatial similarity. Represented by propositions and information units...

Using Arabic Wordnet for semantic indexation in information retrieval system

Abderrahim, Mohammed Alaeddine; Abderrahim, Mohammed El Amine; Chikh, Mohammed Amine
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
68.185293%
In the context of arabic Information Retrieval Systems (IRS) guided by arabic ontology and to enable those systems to better respond to user requirements, this paper aims to representing documents and queries by the best concepts extracted from Arabic Wordnet. Identified concepts belonging to Arabic WordNet synsets are extracted from documents and queries, and those having a single sense are expanded. The expanded query is then used by the IRS to retrieve the relevant documents searched. Our experiments are based primarily on a medium size corpus of arabic text. The results obtained shown us that there are a global improvement in the performance of the arabic IRS.; Comment: 6 pages,2 figures,7 tables

Semantic Information Retrieval Using Ontology In University Domain

Rajasurya, Swathi; Muralidharan, Tamizhamudhu; Devi, Sandhiya; Swamynathan, S.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 24/07/2012 Português
Relevância na Pesquisa
68.62205%
Today's conventional search engines hardly do provide the essential content relevant to the user's search query. This is because the context and semantics of the request made by the user is not analyzed to the full extent. So here the need for a semantic web search arises. SWS is upcoming in the area of web search which combines Natural Language Processing and Artificial Intelligence. The objective of the work done here is to design, develop and implement a semantic search engine- SIEU(Semantic Information Extraction in University Domain) confined to the university domain. SIEU uses ontology as a knowledge base for the information retrieval process. It is not just a mere keyword search. It is one layer above what Google or any other search engines retrieve by analyzing just the keywords. Here the query is analyzed both syntactically and semantically. The developed system retrieves the web results more relevant to the user query through keyword expansion. The results obtained here will be accurate enough to satisfy the request made by the user. The level of accuracy will be enhanced since the query is analyzed semantically. The system will be of great use to the developers and researchers who work on web. The Google results are re-ranked and optimized for providing the relevant links. For ranking an algorithm has been applied which fetches more apt results for the user query.

Ontology-based Secure Retrieval of Semantically Significant Visual Contents

Muhammad, Khan; Mehmood, Irfan; Lee, Mi Young; Ji, Su Mi; Baik, Sung Wook
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 07/10/2015 Português
Relevância na Pesquisa
59.13424%
Image classification is an enthusiastic research field where large amount of image data is classified into various classes based on their visual contents. Researchers have presented various low-level features-based techniques for classifying images into different categories. However, efficient and effective classification and retrieval is still a challenging problem due to complex nature of visual contents. In addition, the traditional information retrieval techniques are vulnerable to security risks, making it easy for attackers to retrieve personal visual contents such as patients records and law enforcement agencies databases. Therefore, we propose a novel ontology-based framework using image steganography for secure image classification and information retrieval. The proposed framework uses domain-specific ontology for mapping the low-level image features to high-level concepts of ontologies which consequently results in efficient classification. Furthermore, the proposed method utilizes image steganography for hiding the image semantics as a secret message inside them, making the information retrieval process secure from third parties. The proposed framework minimizes the computational complexity of traditional techniques, increasing its suitability for secure and real-time visual contents retrieval from personalized image databases. Experimental results confirm the efficiency...

Search for Hidden Knowledge in Collective Intelligence dealing Indeterminacy Ontology of Folksonomy with Linguistic Pragmatics and Quantum Logic

Mas, Massimiliano Dal
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 24/05/2011 Português
Relevância na Pesquisa
58.82136%
Information retrieval is not only the most frequent application executed on the Web but it is also the base of different types of applications. Considering collective intelligence of groups of individuals as a framework for evaluating and incorporating new experiences and information we often cannot retrieve such knowledge being tacit. Tacit knowledge underlies many competitive capabilities and it is hard to articulate on discrete ontology structure. It is unstructured or unorganized, and therefore remains hidden. Developing generic solutions that can find the hidden knowledge is extremely complex. Moreover this will be a great challenge for the developers of semantic technologies. This work aims to explore ways to make explicit and available the tacit knowledge hidden in the collective intelligence of a collaborative environment within organizations. The environment was defined by folksonomies supported by a faceted semantic search. Vector space model which incorporates an analogy with the mathematical apparatus of quantum theory is adopted for the representation and manipulation of the meaning of folksonomy. Vector space retrieval has been proven efficiency when there isn't a data behavioural because it bears ranking algorithms involving a small number of types of elements and few operations. A solution to find what the user has in mind when posing a query could be based on "joint meaning" understood as a joint construal of the creator of the contents and the reader of the contents. The joint meaning was proposed to deal with vagueness on ontology of folksonomy indeterminacy...

A Semantic Enhanced Model for effective Spatial Information Retrieval

Akanbi, Adeyinka K.; Agunbiade, Olusanya Y.; Kuti, Sadiq; Dehinbo, Olumuyiwa J.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 08/06/2014 Português
Relevância na Pesquisa
68.835503%
A lot of information on the web is geographically referenced. Discovering and retrieving this geographic information to satisfy various users needs across both open and distributed Spatial Data Infrastructures (SDI) poses eminent research challenges. However, this is mostly caused by semantic heterogeneity in users query and lack of semantic referencing of the Geographic Information (GI) metadata. To addressing these challenges, this paper discusses ontology based semantic enhanced model, which explicitly represents GI metadata, and provides linked RDF instances of each entity. The system focuses on semantic search, ontology, and efficient spatial information retrieval. In particular, an integrated model that uses specific domain information extraction to improve the searching and retrieval of ranked spatial search results.; Comment: 7 pages, 9 figures

A Hybrid Approach to Finding Relevant Social Media Content for Complex Domain Specific Information Needs

Cameron, Delroy; Sheth, Amit; Jaykumar, Nishita; Thirunarayan, Krishnaprasad; Anand, Gaurish; Smith, Gary A.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 13/11/2014 Português
Relevância na Pesquisa
59.00965%
While contemporary semantic search systems offer to improve classical keyword-based search, they are not always adequate for complex domain specific information needs. The domain of prescription drug abuse, for example, requires knowledge of both ontological concepts and 'intelligible constructs' not typically modeled in ontologies. These intelligible constructs convey essential information that include notions of intensity, frequency, interval, dosage and sentiments, which could be important to the holistic needs of the information seeker. We present a hybrid approach to domain specific information retrieval (or knowledge-aware search) that integrates ontology-driven query interpretation with synonym-based query expansion and domain specific rules, to facilitate search in social media. Our framework is based on a context-free grammar (CFG) that defines the query language of constructs interpretable by the search system. The grammar provides two levels of semantic interpretation: 1) a top-level CFG that facilitates retrieval of diverse textual patterns, which belong to broad templates and 2) a low-level CFG that enables interpretation of certain specific expressions that belong to such patterns. These low-level expressions occur as concepts from four different categories of data: 1) ontological concepts...

A Generalized Framework for Ontology-Based Information Retrieval Application to a public-transportation system

Zidi, Amir; Abed, Mourad
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 02/09/2014 Português
Relevância na Pesquisa
69.13781%
In this paper we present a generic framework for ontology-based information retrieval. We focus on the recognition of semantic information extracted from data sources and the mapping of this knowledge into ontology. In order to achieve more scalability, we propose an approach for semantic indexing based on entity retrieval model. In addition, we have used ontology of public transportation domain in order to validate these proposals. Finally, we evaluated our system using ontology mapping and real world data sources. Experiments show that our framework can provide meaningful search results.

Ontology Based Query Expansion Using Word Sense Disambiguation

Barathi, M.; Valli, S.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 07/03/2010 Português
Relevância na Pesquisa
58.835503%
The existing information retrieval techniques do not consider the context of the keywords present in the user's queries. Therefore, the search engines sometimes do not provide sufficient information to the users. New methods based on the semantics of user keywords must be developed to search in the vast web space without incurring loss of information. The semantic based information retrieval techniques need to understand the meaning of the concepts in the user queries. This will improve the precision-recall of the search results. Therefore, this approach focuses on the concept based semantic information retrieval. This work is based on Word sense disambiguation, thesaurus WordNet and ontology of any domain for retrieving information in order to capture the context of particular concept(s) and discover semantic relationships between them.; Comment: Pages IEEE format, International Journal of Computer Science and Information Security, IJCSIS February 2010, ISSN 1947 5500, http://sites.google.com/site/ijcsis/

Formal Concept Analysis for Information Retrieval

Qadi, Abderrahim El; Aboutajedine, Driss; Ennouary, Yassine
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 07/03/2010 Português
Relevância na Pesquisa
68.24156%
In this paper we describe a mechanism to improve Information Retrieval (IR) on the web. The method is based on Formal Concepts Analysis (FCA) that it is makes semantical relations during the queries, and allows a reorganizing, in the shape of a lattice of concepts, the answers provided by a search engine. We proposed for the IR an incremental algorithm based on Galois lattice. This algorithm allows a formal clustering of the data sources, and the results which it turns over are classified by order of relevance. The control of relevance is exploited in clustering, we improved the result by using ontology in field of image processing, and reformulating the user queries which make it possible to give more relevant documents.; Comment: Pages IEEE format, International Journal of Computer Science and Information Security, IJCSIS, Vol. 7 No. 2, February 2010, USA. ISSN 1947 5500, http://sites.google.com/site/ijcsis/

Topic Map: An Ontology Framework for Information Retrieval

Kannan, Rajkumar
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 18/03/2010 Português
Relevância na Pesquisa
68.27967%
The basic classification techniques for organizing information are thesauri, taxonomy and faceted classification. Topic map is relatively a new entrant to this information space. Topic map standard describes how complex relationships between abstract concepts and real world resources can be represented using XML syntax. This paper explores how topic map incorporates the traditional techniques and what are its advantages and disadvantages in several dimensions such as content management, indexing, knowledge representation, constraint specification and query languages in the context of information retrieval. The constructs of topic maps are illustrated with a use-case implemented in XTM; Comment: National Conference on Advances in Knowledge Management(NCAKM'10), pp195-198, March 2010, India

Information retrieval for reducing manual effort in biomedical and clinical research

Zhu, Dongqing
Fonte: University of Delaware Publicador: University of Delaware
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
68.417905%
Carterette, Benjamin A.; Medical professionals leverage health-related data to address questions and support decision-makings. However, many of these medical tasks require intensive manual effort in identifying useful information in the noisy data. The rapid growth of data is making these tasks more and more costly and time-consuming. In this thesis, we develop effective medical information retrieval (IR) systems to reduce search-related manual work for three representative medical related tasks, namely electronic medical records (EMR) based cohort identification, Medical Subject Headings (MeSH) indexing, and gene ontology annotation (GOA). For cohort identification, we improve the search precision and recall from three aspects: 1) we design a multi-level evidence aggregation strategy for effective merging and scoring of the distributed evidence in EMR; 2) we develop a novel statistical IR model that significantly alleviates two medical language related issues in medical IR; 3) we further enhance the search performance by effectively incorporating domain knowledge into our system. For MeSH indexing and GOA, we demonstrate how to use IR to address specific needs. In particular, we investigate different query formulation methods and explore various ways in which IR work together with other techniques such as Natural Language Processing and Machine Learning.; University of Delaware...

Mapeamento da Produção Científica no Escopo da Ontologia; MAPPING OF THE SCIENTIFIC PRODUCTION IN SCOPE OF THE ONTOLOGY; MAPPING OF THE SCIENTIFIC PRODUCTION IN SCOPE OF THE ONTOLOGY

Dias, Elizabeth Abib Vasconcelos; UNIVERSIDADE FEDERAL FLUMINENSE; Costa, Helder Gomes; UNIVERSIDADE FEDERAL FLUMINENSE
Fonte: Universidade Federal Fluminense - LATEC Publicador: Universidade Federal Fluminense - LATEC
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; Revisão de Literatura Formato: application/pdf
Publicado em 05/06/2012 Português
Relevância na Pesquisa
59.05472%
Ontologias são instrumentos de controle terminológico utilizadas na recuperação da informação de domínios específicos do conhecimento. No tocante a sistemas informatizados significam hoje, o que há de mais avançado na área de representação do conhecimento e na promoção da interoperabilidade entre sistemas processados por máquina. Este trabalho propõe-se a identificar os artigos de periódicos essenciais para a inicialização de estudos sobre este tema, obtidos de três bases de dados internacionais responsáveis pela indexação de títulos de periódicos científicos de primeira linha. A metodologia utilizada para este fim advém de um modelo de mineração de fontes bibliográficas baseado em ferramentas de acesso e busca a dados aplicado em bases de dados disponíveis através do Portal de Periódicos da Capes na Internet. Integra conceitos de Bibliometria, Webmetria e de Mineração de textos. Os resultados obtidos indicam que a técnica pode ser positiva para os fins propostos.; Ontologies are tools for terminology used in information retrieval of specific areas of knowledge. With respect to computer systems mean today, which is most advanced in the area of knowledge representation and promoting interoperability between systems processed by machine. This study aims to identify journal articles essential for the initiation of studies on this subject...

Ontology: ambiguity and accuracy; Ontologia: ambiguidade e precisão

Schiessl, Marcelo; Universidade de Brasília; Bräscher, Marisa; Universidade Federal de Santa Catarina
Fonte: Departamento de Ciência da Informação – UFSC Publicador: Departamento de Ciência da Informação – UFSC
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; Formato: application/pdf
Publicado em 17/08/2012 Português
Relevância na Pesquisa
58.744194%
Ambiguity is a major obstacle to information retrieval. It is source of several researches in Information Science. Ontologies have been studied in order to solve problems related to ambiguities. Paradoxically, “ontology” term is also ambiguous and it is understood according to the use by the community. Philosophy and Computer Science seems to have the most accentuated difference related to the term sense. The former holds undisputed tradition and authority. The latter, in despite of being quite recent, holds an informal sense, but pragmatic. Information Science acts ranging from philosophical to computational approaches so as to get organized collections based on balance between users’ necessities and available information. The semantic web requires informational cycle automation and demands studies related to ontologies. Consequently, revisiting relevant approaches for the study of ontologies plays a relevant role as a way to provide useful ideas to researchers maintaining philosophical rigor, and convenience provided by computers.; http://dx.doi.org/10.5007/1518-2924.2012v17nesp1p125 A ambiguidade é um grande obstáculo para a recuperação de informação. Tanto que ela é fonte de várias pesquisas na Ciência da Informação. As ontologias têm sido estudadas com foco na resolução de problemas oriundos de tais ambiguidades. Paradoxalmente...

Cross Language Information Retrieval using Multilingual Ontology as Translation and Query Expansion Base

Abusalah,Mustafa; Tait,John; Oakes,Michael
Fonte: Instituto Politécnico Nacional, Centro de Innovación y Desarrollo Tecnológico en Cómputo Publicador: Instituto Politécnico Nacional, Centro de Innovación y Desarrollo Tecnológico en Cómputo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2009 Português
Relevância na Pesquisa
68.88775%
This paper reports an experiment to evaluate a Cross Language Information Retrieval (CLIR) system that uses a multilingual ontology to improve query translation in the travel domain. The ontology-based approach significantly outperformed the Machine Readable Dictionary translation baseline using Mean Average Precision as a metric in a user-centered experiment.