Large Integrating formal verification methods of quantitative real-time properties into a development environment for robot controllers

In this paper we describe our experience with a development environment for robot controllers, which provides the user with formal verification functionalities. We study how to augment these functionalities by also allowing formal verification of quantitative real-time properties. Our approach is based on the timed extension of a synchronous language, named Timed-Argos, and on a symbolic model-checking tool named Kronos for the real-time temporal logic TCTL. We illustrate this approach by a real example taken from the area of autonomous vehicles, which poses some challenges on the applicability of the theory and finally, we discuss some possible solutions. This {\em large-scale} real application is also an opportunity to identify new research directions in the area of formal verification

Visualization of Constrainted-based Temporal Scenarios in a Multimedia Authoring Tool

Authoring a multimedia document is known to be a non-trivial task. The use of constraints technology is a good way to ease this task if constraints specification are associated to a powerful visual interface. We discuss in this paper the main requirements for the design of such an interface and we present our proposition experimented in Madeus a constraint-based authoring environment

Presentation Services in MADEUS: an Authoring Environment for Multimedia Documents

The recent advances in multimedia systems, together with the advent of high speed networks, paved the way to a new generation of applications. In particular, authoring environments have found in multimedia the means of increasing the richness of information contained in electronic documents. One of the goals of the Opera team is designing an authoring environment for multimedia documents, called MADEUS, which meets the following requirements: a high level of expressiveness for both spatial and temporal dimensions; a user-friendly interface allowing highly interactive design process, scriptless and structured-based editing and automatic production of spatial and temporal layout; the portability and cross-platform interchange of multimedia documents. To achieve this research goal we first focus on finding a good representation of time for multimedia documents. This representation is required to capture the temporal dimension of media objects like video, audio, etc. and is also used to temporally organize objects with respect to each other. Time representation is clearly the main difference between multimedia authoring environment and traditional editing environments. We present in this paper our first investigational results in our experimental authoring environment MADEUS. A large part of these results are based on the experience acquired in implementing the MADEUS prototype

Double threading through DNA: NMR structural study of a bis-naphthalene macrocycle bound to a thymine–thymine mismatch

The macrocyclic bis-naphthalene macrocycle (2,7-BisNP), belonging to the cyclobisintercalator family of DNA ligands, recognizes T–T mismatch sites in duplex DNA with high affinity and selectivity, as evidenced by thermal denaturation experiments and NMR titrations. The binding of this macrocycle to an 11-mer DNA oligonucleotide containing a T–T mismatch was studied using NMR spectroscopy and NMR-restrained molecular modeling. The ligand forms a single type of complex with the DNA, in which one of the naphthalene rings of the ligand occupies the place of one of the mismatched thymines, which is flipped out of the duplex. The second naphthalene unit of the ligand intercalates at the A-T base pair flanking the mismatch site, leading to encapsulation of its thymine residue via double stacking. The polyammonium linking chains of the macrocycle are located in the minor and the major grooves of the oligonucleotide and participate in the stabilization of the complex by formation of hydrogen bonds with the encapsulated thymine base and the mismatched thymine remaining inside the helix. The study highlights the uniqueness of this cyclobisintercalation binding mode and its importance for recognition of DNA lesion sites by small molecules

Etude d'un environnement de programmation et de vérification des systèmes réactifs, multi-langages et multi-outils

This thesis deals with the programmation and verification of reactive systemes. In a first part, we define a multiparadigm langage nammed ArgoLus. ArgoLus is based on Argos and Lustre, two synchronous langages. In order to describe reactive systemes Argos uses a modular state/transition approach, while Lustre uses data-flow constructs. In the ArgoLus langage these two styles are mixed. The idea is to allow the description of elementary objects in each of the two styles, and their combination with both constructs. In a second part, we define the Argos semantic in terms of timed graphs. The initial semantic of Argos is expressed in terms of labelled transition systems. The drawback of this model is the well-known phenomenom of state explosion which occurs when large counters of event occurrences are used in the program. This state explosion reduces the formal verification possibilities. The advantage of timed graphs, which are automata extended with time counters, is that their size is independant from the delay values of the counters used in the program. Consequently, this model is less sensitive to the state explosion problem, so the possibilities of formal verification are improved. Moreover, it is possible with this kind of model to express quantitative real-time properties. Finally, we study the possibility of using a large class of formal verification tools not exactly designed for reactive systemsCe travail porte sur la programmation et la verification des systemes reactifs. Il consiste dans une premiere partie en la definition d'un langage mixte imperatif/declaratif, nomme ArgoLus, fonde sur les langages synchrones Argos et Lustre. Argos est un langage imperatif a base d'automates paralleles et hierarchises. Lustre est un langage declaratif fonde sur le modele flots de donnees. Le langage ArgoLus permet de melanger au niveau source ces deux langages. La definition des traductions structurelles d'ArgoLus en Argos ou en Lustre offre deux solutions interessantes pour mettre en oeuvre ce langage, tout en profitant des environnements deja existants. Dans un deuxieme temps la semantique d'Argos en termes de graphes temporises a ete definie. Initialement, celle-ci est definie en termes de systemes de transitions etiquetees. L'inconvenient de ce modele est lie au phenomene d'explosion du nombre d'etats qui limite les possibilites de verification formelle. Une des causes de cette explosion est la presence dans les programmes de compteurs d'occurrences d'evenement. Les graphes temporises sont des automates etendus avec des compteurs de temps, dont la taille est independante des valeurs limites des compteurs du programme. Par consequent, ils sont moins sensibles au phenomene d'explosion du nombre d'etats, d'ou une amelioration des possibilites de verification formelle. De plus, il est possible grace a ce modele d'exprimer des proprietes quantitatives faisant reference au temps. Enfin, un troisieme aspect de ce travail porte sur l'utilisation pour les systemes reactifs d'outils de verification formelle, non concus exactement pour ce type de systemes

Visualization of Constrainted-Based Temporal Scenarios in a Multimedia Authoring Tool

: Authoring a multimedia document is known to be a non-trivial task. The use of constraints technology is a good way to ease this task if constraints specification are associated to a powerful visual interface. We discuss in this paper the main requirements for the design of such an interface and we present our proposition experimented in Madeus a constraint-based authoring environment. Key-words: authoring environment , multimedia document, temporal constraints visualization (R'esum'e : tsvp) Unite de recherche INRIA Rhone-Alpes 655, avenue de l'Europe, 38330 MONTBONNOT ST MARTIN (France) Telephone : (33) 76 61 52 00 -- Telecopie : (33) 76 61 52 Visualisation de contraintes temporelles dans un environnement d"edition multim'edia R'esum'e : L"edition de documents multim'edia est une tache complexe. L'utilisation de contraintes temporelles pour la sp'ecification du sc'enario temporel du document facilite cette phase de conception. Cependant, le besoin en une interface visuelle de h..

User Interface of a New Generation of Authoring Environment of Multimedia Documents

this paper the main requirements for the design of such an interface and we present our proposition experimented in our constraint-based authoring environment called Madeus [Jou97a]. A more detailed presentation of these aspects could be found in [Jou97b]