Representation and Acquisition of Knowledge of Fucntional Systems

Many experimental studies have shown that learning and memorization of complex information are strongly influenced by the learners' prior knowledge. Thus, detailed analyses of the structures and the processes involved in learning and memorization require precise assessment of the leamer's prior knowledge in relation to the characteristics of the domain to be acquired. W e have developed a formalization in terms of systems: relational, transformational, teleological (functional and intentional) which permits us to simultaneously describe that domain being acquired, the representaion of the acquiring organism, and our representation of that representation. Here, we will report a study in which this formalization was employed in assessing the representation that students with different levels of knowledge about automobile mechanics have of a functional system: the starter system of an automobile. The predictions made by this formalization were compared with the performances of three groups of students with different levels of knowledge on a series of four tasks: free interview, causal questioning, completing lacunary event triples, and a multiple choice questionaire on the existence of events and causal relations. The criterium used to choose these four tasks was that they differ according to the demands they make in the retrieval of stored information in memory. The results show that: (i) subjects with a good level of knowledge have a representation organized in a fuctional autonomous system organized in sub-systems, while (ii) subjects with lower levels of knowledge do not have a representation organized as a functional system, and (iii) subjects from the intermediate group built a representation organized as a functional autonomous system but containing less information and more poorly organized in sub-systems

Economic and environmental strategies for process design

This paper first addresses the definition of various objectives involved in eco-efficient processes, taking simultaneously into account ecological and economic considerations. The environmental aspect at the preliminary design phase of chemical processes is quantified by using a set of metrics or indicators following the guidelines of sustainability concepts proposed by . The resulting multiobjective problem is solved by a genetic algorithm following an improved variant of the so-called NSGA II algorithm. A key point for evaluating environmental burdens is the use of the package ARIANE™, a decision support tool dedicated to the management of plants utilities (steam, electricity, hot water, etc.) and pollutants (CO2, SO2, NO, etc.), implemented here both to compute the primary energy requirements of the process and to quantify its pollutant emissions. The well-known benchmark process for hydrodealkylation (HDA) of toluene to produce benzene, revisited here in a multiobjective optimization way, is used to illustrate the approach for finding eco-friendly and cost-effective designs. Preliminary biobjective studies are carried out for eliminating redundant environmental objectives. The trade-off between economic and environmental objectives is illustrated through Pareto curves. In order to aid decision making among the various alternatives that can be generated after this step, a synthetic evaluation method, based on the so-called Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) (), has been first used. Another simple procedure named FUCA has also been implemented and shown its efficiency vs. TOPSIS. Two scenarios are studied; in the former, the goal is to find the best trade-off between economic and ecological aspects while the latter case aims at defining the best compromise between economic and more strict environmental impact

La mémorisation de récit chez l'enfant d'âge pré­scolaire, origine sociale et accès à l'information stockée en mémoire

Summary : Memorization of stories by pre-school children : social background and access to information stored in memory. The purpose of this article is to enquire into the elements of the memorizing process likely to be responsible for the observed differences between social classes in the recall of stories. Two assumptions are tested : that of a differential erasure of information stored in memory and that of a differential access to this information. These are tested on the basis of a simplified model of the meaning of stories represented by a hierarchized and coherent set of propositions organized in clusters, and of an access model : to use hierarchical and coherent features for guiding retrieval of memory information. A test of immediate free recall followed by a differed cued recall (7 days) of the same figurative stories was carried out ivith 2 groups of 30 children, 5 years old, from different social backgrounds. The cues used were either drawings (of the figurative stories) of different relative importance, or of drawings illustrating information that coula be inferred from the story. The analysis shows that : — results are compatible with predictions made from the proposed access model ; — recall by childern coming from disadvantaged social classes being not so good can be explained by a differential access to information stored in memory. This inferiority is principally due to the relative lack of coherence in meaning and to the lack of using the existing coherence to guide access. Keywords : story meaning, differential access, relative importance, coherence.Résumé : La mémorisation de récit chez l'enfant d'âge pré-scolaire : origine sociale et accès à l'information stockée en mémoire. L'objet de l'article est de rechercher les éléments du processus de mémorisation qui seraient responsables des différences entre classes sociales observées dans le rappel de récit. Deux hypothèses sont testées : celle d'un effacement différentiel de l'information conservée en mémoire et celle d'un accès différentiel à cette information. Elles le sont dans le cadre d'un modèle simplifié de la signification du récit qui la représente par un ensemble hiérarchisé et cohérent de propositions organisées en grappes et d'un modèle d'accès : utilisation de ces caractéristiques hiérarchiques et de cohérence pour guider la récupération de l'information mémorielle. Une expérience de rappel libre immédiat suivi d'un rappel indicé différé (7 jours) des mêmes récits figuratifs a été menée avec deux groupes de 30 enfants de 5 ans contrastés selon l'origine sociale. Les indices utilisés étaient soit des dessins (du récit figuratif) d'importance relative différente soit des dessins illustrant une information inférable à partir du récit. L'analyse montre que : — les résultats sont compatibles avec les prédictions faites à partir du modèle d'accès proposé ; — le rappel moins bon des enfants du milieu défavorisé s'explique par un accès différentiel à l'information stockée en mémoire. Cette infériorité est principalement attribuable à un manque relatif de cohérence dans la signification et au manque d'utilisation de la cohérence existante pour guider l'accès. Mots clés : signification du récit, accès différentiel, importance relative, cohérence.Baudet Serge. La mémorisation de récit chez l'enfant d'âge pré­scolaire, origine sociale et accès à l'information stockée en mémoire. In: L'année psychologique. 1986 vol. 86, n°2. pp. 223-246

Représentations cognitives d'état, d'événement et d'action

Baudet Serge. Représentations cognitives d'état, d'événement et d'action. In: Langages, 25ᵉ année, n°100, 1990. Cognition et Langage, sous la direction de Jacques François et Guy Denhière. pp. 45-64

Plant Protection in Mediterranean Agroecosystems

National audienc

Coherence and Truth: a cognitive model of propositional truth attribution

International audienc

Un couplage entre un algorithme génétique et un modèle de simulation pour l'ordonnancement à court terme d'un atelier discontinu de chimie fine

In this paper, a discrete-event simulation model is coupled with a genetic algorithm to treat highly combinatorial scheduling problems encountered in a production campaign of a fine chemistry plant. The main constraints and features of fine chemistry have been taken into account in the development of the model, thus allowing a realistic evaluation of the objective function used in the stochastic optimization procedure. After a presentation of problem combinatorics, the coupling strategy is then proposed and illustrated by an example of industrial size (24 equipment items, 140 products, 12 different production recipes and 40 products to be recycled during the campaign). This example serves as an incentive to show how the approach can improve production performance. Three technical criteria have been studied: campaign completion time, average product cycle time, respect of due-dates. Two kinds of optimization variables have been considered: product input order and/or allocation of heuristics for conflit treatment. The results obtained are then analysed and some perspectives of this work are presented