• Co-Supervisors :
  • Badran Raddaoui (Telecom SudParis
  • laboratoire SAMOVAR)
  • Yue Ma (Université Paris Saclay
  • LISN)
  • Funding : ANR
  • Start year :
  • 2024

This PhD thesis will focus on the following two main aspects. The first one concerns query answering semantics with inconsistent databases. Despite the fact that various methods have been studied, for drawing useful information in presence of conflicts in the propositional and description logic settings [2, 5], we are not aware of any existing work studying rich conflict-tolerant relations in the context of databases equipped with flexible preference relations [7], such as the partially ordered relation (e.g., [1, 3]). Then, investigating database query answering under such varying conflict-tolerant methods should be accompanied by studying the computational complexity of the different related problems, which is among the main objectives of this thesis.

The second objective of the thesis is how to handle preferences in conflicting databases. In fact, to answer queries over conflicting databases, it is crucial to express priority among potential repairs in order to select the most optimal candidates. As the number of potential repairs can be (very) large, one may choose to rank repairs according to some preference criteria, and select a small number of the most desirable repairs. Moreover, we note that the preference among the sources of data could be of different nature. Often, conflict-tolerant methods aim to find a stratification inducing a total preorder among all pieces of information. Such a stratification allows us to handle inconsistencies in data sources. Nonetheless, this can lead to a comparison of incomparable and independent pieces of information. The main objective here is then to develop a new framework to handle preferences in conflicting databases in order to draw meaningful answers to user queries.

Références

[1] Sihem Belabbes, Salem Benferhat, and Jan Chomicki. Handling inconsistency in partially preordered ontologies: the elect method. J. Log. Comput., 31(5):1356–1388, 2021. [2] Meghyn Bienvenu. Inconsistency handling in ontology-mediated query answering: A progress report. In DL, 2019. [3] Saïd Jabbour, Yue Ma, and Badran Raddaoui. A framework for reasoning about uncertainty in ontologies. IEEE Intell. Syst., 37(6):27–37, 2022. [4] Benny Kimelfeld, Ester Livshits, and Liat Peterfreund. Counting and enumerating preferred database repairs. Theor. Comput. Sci., 837:115–157, 2020. [5] Sébastien Konieczny, Pierre Marquis, and Srdjan Vesic. Rational inference relations from maximal consistent subsets selection. In IJCAI, pages 1749–1755, 2019. [6] Ester Livshits and Benny Kimelfeld. The shapley value of inconsistency measures for functional dependencies. In ICDT, pages 15:1–15:19, 2021. [7] Slawek Staworko, Jan Chomicki, and Jerzy Marcinkowski. Prioritized repairing and consistent query answering in relational databases. Ann. Math. Artif. Intell., 64(2-3):209–246, 2012.