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Defesa de Dissertação de Mestrado Nº 1.335: "Information Quality Criteria Analysis in Query Reformulation in Dynamic Distributed Environments"

O aluno Bruno Felipe de França Souza irá defender seu trabalho dia 9 de setembro, às 8h, no Auditório Início: 09/09/2013 às 08:00 Término: 09/09/2013 às 10:00 Local: Auditório do CIn

Pós-Graduação em Ciência da Computação – UFPE
Defesa de Dissertação de Mestrado Nº 1.335
Aluno: Bruno Felipe de França Souza
Orientador: Profa. Ana Carolina Salgado
Co-orientador: Profa. Maria da Conceição Morais Batista (DEINFO/UFRPE)
Título: Information Quality Criteria Analysis in Query Reformulation in Dynamic Distributed Environments
Data: 09/09/2013
Hora/Local: 8:00h – Auditório
Banca Examinadora:
Profa. Bernadette Farias Lóscio  (UFPE / CIn)
Prof. Carlos Eduardo Pires  (UFCG / Departamento de Sistemas e Computação)
Profa. Ana Carolina Salgado  (UFPE / CIn)
Dynamic distributed environments are decentralized systems that provide users with querying capabilities over a set of heterogeneous, distributed and autonomous data sources (peers). Data Integration Systems, Peer Data Management Systems (PDMS) and Dataspaces are examples of such systems. They are composed by peers that belong to a specific domain and are linked to each other by correspondences (semantic connections). Nonetheless, a challenge inherent to dynamic distributed environments is the query reformulation process between a pair of peers. When a user poses a query at a peer, in order to acquire more information, the query should be reformulated in accordance with the neighbor peers schema. In this process some problems as semantic loss and query degradation can arise.
The semantic loss and query degradation are problems related to the loss of semantic concepts during query reformulation. In the other hand, in such a semantic environment instead of a semantic loss the query can have a semantic enrichment by aggregating semantic related concepts during reformulation. In this sense, the user’s query can be enriched and semantically richer results can be delivered.
Information Quality criteria has been used in some works to evaluate the level of quality of the distributed dynamic environment’s elements such as, peers, data and query answer. These criteria are dynamic measures provided by the system and serves as scores that can be constantly evaluated to get the actual level of quality.
In this work we present four Information Quality criteria that measure the loss and gain of semantic concepts during query reformulation among peers. We present an example of our approach and the algorithms that implement the evaluation of the presented criteria. We also give our definitions to the semantic loss and query degradation problems. Finally, we present the experimentation we have done with the PDMS SPEED and the obtained results.
Palavras-chave: Query Reformulation, Information Quality, PDMS, Distributed Dynamic Environment, Semantic Correspondences 
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