Les devoirs à domicile :: communication entre parents et enseignants

Aujourd’hui, les devoirs à domicile sont toujours et encore au coeur des débats exposant enseignants, enfants et parents. Ces trois acteurs des devoirs à domicile possèdent chacun leur opinion concernant ceux-ci. De ce fait, il n’est pas étonnant qu’il y ait des malentendus entre ces trois acteurs. De plus, l’enfant n’a pas un rôle évident à jouer se trouvant « coincé » entre ces deux personnes de référence. Je souhaite donc m’approcher d’enseignants et de parents afin de récolter leurs représentations et d’observer quelle est la tendance actuelle. Le but de ma recherche est de découvrir quelles sont les pratiques des enseignants et des parents, et de découvrir comment ces derniers agissent respectivement en matière de devoirs à domicile. Autrement dit, comment fonctionnent-ils, l’enseignant dans sa classe et les parents à la maison. Je désire comprendre pour quelles raisons enseignants, enfants et parents sont parfois confrontés à des malentendus. Qu’en est-il de la communication entre ces trois acteurs ? Doit-elle être optimisée dans le cadre des devoirs à domicile ? Je souhaite découvrir s’il y a un moyen d’éviter de stresser les parents, de les faire culpabiliser ou encore d’empoisonner leurs soirées en familles comme se questionnent également Dubois et Navarro-Dubois (2004)

Negation by default and unstratifiable logic programs

AbstractThe default approach to the theory of logic programs (and deductive databases) is based on the interpretation of negation by default rules. Default logic is a well-suited formalism to express the Closed World Assumption and to define the declarative semantics of stratifiable logic programs. The case of disjunctive consequences in rules is treated. General logic programs may not have a meaning with respect to default semantics. The contribution of the paper is to exhibit an interesting class of programs having a default semantics, called effectively stratifiable programs. This time, disjunctive consequences are not considered. Effective stratification is a weaker constraint than stratification, local stratification and weak stratification. Besides enlarging the class of stratifiable logic programs, the paper contributes to provide a constructive definition of well-founded models of logic programs. The class of effectively stratifiable logic programs matches the class of programs having a total well-founded model and in general, the default semantics extends the well-founded semantics

General logical databases and programs: Default logic semantics and stratification

AbstractDefault logic is introduced as a well-suited formalism for defining the declarative semantics of deductive databases and logic programs. After presenting, in general, how to use default logic in order to define the meaning of logical databases and logic programs, the class of stratifiable databases and programs is extensively studied in this framework. Finally, the default logic approach to the declarative semantics of logical databases and programs is compared with the other major approaches. This comparison leads to showing some advantages of the default logic approach

Réécriture de workflows scientifiques et provenance

National audienceLes systèmes de workflow sont nombreux et disposent de modules de gestion de provenance qui collectent les informations relatives aux exécutions (données consommées et produites) permettant d'assurer la reproductibilité d'une expérience. Un grand nombre d'approches s'est développé pour aider à la gestion de ces masses de données de provenance. Un certain nombre de ces approches ont une bonne complexité parce qu'elles sont dédiées à des structures de workflows série-parallèles. Réécrire un workflow en un workflow série-parallèle permettrait donc de mieux exploiter l'ensemble des outils de provenance existants. Nos contributions sont : (i) introduction de la notion de réécriture de workflow provenance-equivalence, (ii) revue de transformations de graphes, (iii) conception de l'algorithme de réécriture SPFlow préservant la provenance (iv) évaluation de notre approche sur un millier de workflows

Synthesis of Boolean Networks from Biological Dynamical Constraints using Answer-Set Programming

International audienceBoolean networks model finite discrete dynamical systems with complex behaviours. The state of each component is determined by a Boolean function of the state of (a subset of) the components of the network. This paper addresses the synthesis of these Boolean functions from constraints on their domain and emerging dynamical properties of the resulting network. The dynamical properties relate to the existence and absence of trajectories between partially observed configurations, and to the stable behaviours (fixpoints and cyclic attractors). The synthesis is expressed as a Boolean satisfiability problem relying on Answer-Set Programming with a parametrized complexity, and leads to a complete non-redundant characterization of the set of solutions. Considered constraints are particularly suited to address the synthesis of models of cellular differentiation processes, as illustrated on a case study. The scalability of the approach is demonstrated on random networks with scale-free structures up to 100 to 1,000 nodes depending on the type of constraints

Distilling Structure in Scientific Workflows

International audienceIn this work, we have conducted a series of experiments to better understand the structure of scientific workflows. In particular, we have investigated techniques to understand why scientific workflows may or may not have a series-parallel structure

Path-based systems to guide scientists in the maze of biological data sources

Fueled by novel technologies capable of producing massive amounts of data for a single experiment, scientists are faced with an explosion of information which must be rapidly analyzed and combined with other data to form hypotheses and create knowledge. Today, numerous biological questions can be answered without entering a wet lab. Scientific protocols designed to answer these questions can be run entirely on a computer. Biological resources are often complementary, focused on different objects and reflecting various experts\u27 points of view. Exploiting the richness and diversity of these resources is crucial for scientists. However, with the increase of resources, scientists have to face the problem of selecting sources and tools when interpreting their data. In this paper, we analyze the way in which biologists express and implement scientific protocols, and we identify the requirements for a system which can guide scientists in constructing protocols to answer new biological questions. We present two such systems, BioNavigation and BioGuide dedicated to help scientists select resources by following suitable paths within the growing network of interconnected biological resources

Distilling structure in Taverna scientific workflows: a refactoring approach

BACKGROUND: Scientific workflows management systems are increasingly used to specify and manage bioinformatics experiments. Their programming model appeals to bioinformaticians, who can use them to easily specify complex data processing pipelines. Such a model is underpinned by a graph structure, where nodes represent bioinformatics tasks and links represent the dataflow. The complexity of such graph structures is increasing over time, with possible impacts on scientific workflows reuse. In this work, we propose effective methods for workflow design, with a focus on the Taverna model. We argue that one of the contributing factors for the difficulties in reuse is the presence of "anti-patterns", a term broadly used in program design, to indicate the use of idiomatic forms that lead to over-complicated design. The main contribution of this work is a method for automatically detecting such anti-patterns, and replacing them with different patterns which result in a reduction in the workflow's overall structural complexity. Rewriting workflows in this way will be beneficial both in terms of user experience (easier design and maintenance), and in terms of operational efficiency (easier to manage, and sometimes to exploit the latent parallelism amongst the tasks). RESULTS: We have conducted a thorough study of the workflows structures available in Taverna, with the aim of finding out workflow fragments whose structure could be made simpler without altering the workflow semantics. We provide four contributions. Firstly, we identify a set of anti-patterns that contribute to the structural workflow complexity. Secondly, we design a series of refactoring transformations to replace each anti-pattern by a new semantically-equivalent pattern with less redundancy and simplified structure. Thirdly, we introduce a distilling algorithm that takes in a workflow and produces a distilled semantically-equivalent workflow. Lastly, we provide an implementation of our refactoring approach that we evaluate on both the public Taverna workflows and on a private collection of workflows from the BioVel project. CONCLUSION: We have designed and implemented an approach to improving workflow structure by way of rewriting preserving workflow semantics. Future work includes considering our refactoring approach during the phase of workflow design and proposing guidelines for designing distilled workflows

Towards a logic-based method to infer provenance-aware molecular networks

International audienceProviding techniques to automatically infer molecular networks is particularly important to understand complex relationships between biological objects. We present a logic-based method to infer such networks and show how it allows inferring signalling networks from the design of a knowledge base. Provenance of inferred data has been carefully collected, allowing quality evaluation. More precisely, our method (i) takes into account various kinds of biological experiments and their origin; (ii) mimics the scientist's reasoning within a first-order logic setting; (iii) specifies precisely the kind of interaction between the molecules; (iv) provides the user with the provenance of each interaction; (v) automatically builds and draws the inferred network