About

My profile picture.

I am an assistant lecturer at CRIL (Centre de recherche en Informatique de Lens). I obtained my ph.D. in December 2017 on the topic of “Interval-based possibility theory: Conditioning and probability/possibility transformations”.

My Ph.D. thesis was supervised by Salem Benferhat and Karim Tabia.

Keywords:

  • Possibilistic/Interval-based possibilistic frameworks
  • Graphical models
  • Uncertainty representations
  • Inference in graphical models
  • Reasoning tasks

Link to a compact Curriculum Vitae

Thesis abstract

This thesis contributes to the development of efficient formalisms to handle uncertain information. Existing formalisms such as probability theory or possibility theory are among the most known and used settings to represent such information. Extensions and generalizations (e.g. imprecise probability theory, interval-based possibilistic theory) have been provided to handle uncertainty such as incomplete and ill-known knowledge and reasoning with the knowledge of a group of experts. We are particularly interested in reasoning tasks within these theories such as conditioning.

The contributions of this thesis are divided in two parts. In the first part, we tackle conditioning in interval-based possibilistic framework and set-valued possibilistic framework. The purpose is to develop a conditioning machinery for interval-based possibilistic logic. Conditioning in a standard possibilistic setting differs whether we consider a qualitative or quantitative scale. Our works deal with both definitions of possibilistic conditioning. This leads us to investigate a new extension of possibilistic logic, defined as set-valued possibilistic logic, and its conditioning machinery in the qualitative possibilistic setting. These results, especially in terms of complexity, lead us to study transformations, more precisely from probability to possibility theories. The second part of our contributions deals with probability-possibility transformation procedures. Indeed, we analyze properties of reasoning tasks such as conditioning and marginalization. We also tackle transformations from imprecise probability theory to possibility theory with a particular interest in MAP inference.

Link to the full thesis [pdf]


Research Activities

Project

    I am a member of the AniAge project (High Dimensional Heterogeneous Data based Animation Techniques for Southeast Asian Intangible Cultural Heritage Digital Content). The aim of this project is to develop novel techniques and tools to reduce the production costs and improve the level of automation without sacrificing the control from the artists, in order to preserve the performing art related ICHs of Southeast Asia.



Program/Organizing committees

I have participated to the following program and organizing committees:

International conferences

International schools


Publications

International Journal Papers

International Conference Papers with Proceedings

National Conference Papers

Thesis / Research reports

Bibtex can be found on DBLP Click me!


Teaching

3rd year undergraduate student in Computer Sciences

    Lambda calculus and functional programming: Haskell
  • 16h of Practical Sessions

    Script langage: Web design using PHP HTML CSS PHP PHPMyAdmin
  • 14h of Lectures
  • 6h of Tutorials
  • 26h of Practical Sessions

    Advanced Database systems MySQL PostgreSQL
  • 18h of Practical Sessions

2nd year undergraduate student in Computer Sciences

    Database systems SQLite
  • 7h of Practical Sessions

    Object-oriented programming Java
  • 36h of Practical Sessions

1st year undergraduate student in Mathematics and Computer Sciences

    Algorithm 1: Introduction to algorithmics and programming Python
  • 48h of Tutorials
  • 48h of Practical Sessions

1st year undergraduate student in Internet and Multimedia Technologies

    Computer Network: Introduction to communication protocoles Shell
  • 9h of Tutorials
  • 36h of Practical Sessions

1st year of undergraduate student in Life Sciences

    Numerical culture: Conception of Documents and Digital Interfaces - Digital culture Office technology Linux
  • 20h of Practical Sessions


Contact

Office: D308
Phone: +33 (0)3 21 79 17 23 (80 04)

Université d’Artois
Faculté des Sciences Jean Perrin
Rue Jean Souvraz SP 18
F-62307 LENS Cedex (France)

My current local time is .

levray@cril.fr