Research Interests | Research Activities | Papers | Teaching | Resume Sketch | Personal

Research Interests

Temporal Representation and Reasoning

I focussed on the study of principles, techniques and applications of representation of and reasoning about time in Artificial Intelligence. My work in this area is organized in the following topics:

Most of the results in these various topics are contained in my PhD thesis. It has been published as the book "On Temporal Representation and Reasoning in Knowledge-based Systems", Series Monografies de l'IIIA, 3, 1995. You can obtain the abstract by clicking here and purchase the thesis book by contacting Mària del Mar Cuñado .



I have studied and compared the most relevant approaches to temporal reasoning in AI in the literature. This study is organized in two papers:

Ontology and Theory of Time

In IP: An Instant-Period-based Theory of Time I propose a theory of time based on instants and periods called IP. Although the theory proposed looks pretty straight forward, the main lesson reported is the fact that the ontological and technical arguments against representing time as a collection of points together with intervals vanish. The paper includes a comparison with other interval and point/interval -based theories proposed in the literature.

In A Theory of Time and Temporal Incidence based on Instants and Periods, E. Schwalb and I further elaborate upon IP by proposing a simple theory of temporal incidence. We again discuss how it can be used to satisfactorily address the classical problems for time theories.

Temporal Qualification Methods

In The Token Reificacion Approach to Temporal Reasoning Han Reichgelt and I propose an original temporal qualification method that enjoys the good sides of both temporal reification and temporal tokens.

Temporal Qualification Survey:

Fuzzy Temporal Reasoning

Lluís Godo and I investigate the representation of vague temporal constraints by using possibilistic logic.

In On Fuzzy Temporal Constraint Networks, we explore the definition and logical combination functions for fuzzy temporal constraints. In Possibilistic Temporal Reasoning based on Fuzzy Temporal Constraints we explore the embedding or the above defined fuzzy temporal constraints into a propositional logic. Possibilistic semantics is used to cope with the fuzzy predicates and their induced uncertainty.


I've been working on the application of temporal representation and reasoning methods in various domains.

Industrial Domain: Process Monitoring

Medical Domain: Medical Diagnosis

Legal Domain: Law Formalization

In Time in Automated Legal Reasoning I study the representation of time in the application context of temporal reasoning. Two paradigmatic application examples are used to illustrate the approach (some ideas have been preliminarily presented in the 3rd Intl. Workshop on Legal Expert Systems for the CISG May 1995).


I have taught the following tutorial courses on temporal reasoning in AI: You may contact the conference tutorial organizers for the tutorial notes.

Intelligent Process Control

Intelligent Process Control by means of Expert Systems and Machine Vision.

Qualitative Reasoning about Physical Systems

Modelling Time in Qualitative Reasoning about Physical Systems.

Constraint Satisfaction Problems

Summarizing CSP hardness with Continuous Probability Distributions.

Research Interests | Research Activities | Papers | Teaching | Resume Sketch | Personal

This page is maintained by Lluís Vila.
Last update: 1 June 99