Handling failing RDF queries: from diagnosis to relaxation

Fokou, Géraud; Jean, Stéphane; Hadjali, Allel; Baron, Mickaël

doi:10.1007/s10115-016-0941-0

Cited by 16 publications

(17 citation statements)

References 28 publications

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“…Query transformations can be useful for taking into account vagueness and for finding results that are related to the query but do not match it exactly. A method proposes a framework to relax query by analysing the failing causes of the initial query [19].…”

Section: Different Tools and Methods Have Been Proposedmentioning

confidence: 99%

Applying and developing semantic web technologies for exploiting a corpus in history of science: The case study of the Henri Poincaré correspondence

Bruneau

Lasolle

Lieber

et al. 2021

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The Henri Poincaré correspondence is a corpus of letters sent and received by this mathematician. The edition of this correspondence is a long-term project begun during the 1990s. Since 1999, a website is devoted to publish online this correspondence with digitized letters. In 2017, it has been decided to reforge this website using Omeka S. This content management system offers useful services but some user needs have led to the development of an RDFS infrastructure associated to it. Approximate and explained searches are managed thanks to SPARQL query transformations. A prototype for efficient RDF annotation of this corpus (and similar corpora) has been designed and implemented. This article deals with these three research issues and how they are addressed.

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Section: Different Tools and Methods Have Been Proposedmentioning

confidence: 99%

Applying and developing semantic web technologies for exploiting a corpus in history of science: The case study of the Henri Poincaré correspondence

Bruneau

Lasolle

Lieber

et al. 2021

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“…His main contributions were (1) the definition of the complexity of the MFSs and XSSs computation problem and (2) the proposition of the ISHMAEL algorithm that computes either MFSs or XSSs by exploring the lattice of subqueries of the initial query. This work was adapted to the RDF context by Fokou et al [5], for which they proposed the LBA approach to compute both MFSs and XSSs. LBA was then extended in αLBA [6] to take into account uncertain RDF data.…”

Section: Related Workmentioning

confidence: 99%

“…MBS therefore acts as a baseline to evaluate the benefits of our optimization. MDMB is also compared to two alternative algorithms: MCS [7] and LBA [5], described in section II. As these approaches (MCS and LBA) have been proposed in non-uncertain contexts, we have adapted these algorithms in order to compare experiments.…”

Section: Experimental Evaluationmentioning

confidence: 99%

Borders of Theories for Cooperative Querying over Uncertain Databases

Belheouane¹,

Jean²,

Chardin³

et al. 2018

2018 IEEE International Conference on Fuzzy Systems (FUZZ-IEEE)

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In many real applications, data are intrinsically uncertain due to measurement errors, interpretability issues, information incompleteness, etc. In those uncertain databases, users usually express quality requirements when the system evaluates their queries. However, as they may not be familiar with the contents of the queried database, their queries may be failing i.e., they may return no results or results that do not satisfy the expected degree of certainty. To provide users with relevant information in order to obtain alternative satisfactory results, we introduce a cooperative approach based on the dualization concept. This approach computes a set of meaningful subqueries (MFSs and XSSs) of the initial failing query, which is of paramount importance for query reformulation and relaxation purposes. The conducted experiments show that our proposition, a Mixed Dualization Matrix-Based approach (MDMB), outperforms existing algorithms, especially for large queries.

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“…In this section, we first give a direct adaptation of the Lattice-Based Approach (LBA) proposed in [4] to compute the αMFSs and αXSSs of a query for a given α. It has the same algorithmic complexity as LBA (detailed in [4]). αLBA explores the lattice of subqueries by following a three-steps procedure.…”

Section: αMfss and αXsss Computation For A Single αmentioning

confidence: 99%

“…The problem of computing MFSs and XSSs of SPARQL queries expressed on KBs has already been addressed by Fokou et al [4]. In this paper, we consider a generalization of MFSs and XSSs in the context of uncertain KBs.…”

Section: Introductionmentioning

confidence: 99%

On Addressing the Empty Answer Problem in Uncertain Knowledge Bases

Dellal

Jean

Hadjali

et al. 2017

Lecture Notes in Computer Science

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Recently, several large Knowledge Bases (KBs) have been constructed by mining the Web for information. As an increasing amount of inconsistent and non-reliable data are available, KBs facts may be uncertain and are then associated with an explicit certainty degree. When querying these uncertain KBs, users seek high quality results i.e., results that have a certainty degree greater than a given threshold α. However, as they usually have only a partial knowledge of the KBs contents, their queries may be failing i.e., they return no result for the desired certainty. To prevent this frustrating situation, instead of returning an empty set of answers, our approach explains the reasons of the failure with a set of αMinimal Failing Subqueries (αMFSs), and computes alternative relaxed queries, called αMaXimal Succeeding Subqueries (αXSSs), that are as close as possible to the initial failing query. Moreover, as the user may not always be able to provide an appropriate threshold α, we propose two algorithms to compute the αMFSs and αXSSs for other thresholds. Our experiments on the WatDiv benchmark show the relevance of our algorithms compared to a baseline method.

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Handling failing RDF queries: from diagnosis to relaxation

Cited by 16 publications

References 28 publications

Applying and developing semantic web technologies for exploiting a corpus in history of science: The case study of the Henri Poincaré correspondence

Applying and developing semantic web technologies for exploiting a corpus in history of science: The case study of the Henri Poincaré correspondence

Borders of Theories for Cooperative Querying over Uncertain Databases

On Addressing the Empty Answer Problem in Uncertain Knowledge Bases

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