Rozprawy doktorskie na temat „Connaissances Représentation des”
Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych
Sprawdź 50 najlepszych rozpraw doktorskich naukowych na temat „Connaissances Représentation des”.
Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.
Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.
Przeglądaj rozprawy doktorskie z różnych dziedzin i twórz odpowiednie bibliografie.
Bel, Bernard. "Acquisition et représentation de connaissances en musique". Phd thesis, Aix-Marseille 3, 1990. http://tel.archives-ouvertes.fr/tel-00009692.
Pełny tekst źródłaAugier, Marc. "Hypertextualité, construction du sens et représentation des connaissances". Phd thesis, Université de Nice Sophia-Antipolis, 2005. http://tel.archives-ouvertes.fr/tel-00080166.
Pełny tekst źródłaL'apparente simplicité de cette description pourrait laisser penser qu'il ne s'agit là que d'"un autre site" offrant des textes électroniques en libre accès sur le Web.
Le premier objet d'étude est lié à l'analyse des nouveaux usages d'un corpus de littérature sous
format électronique. En fait, la mise en place de ce site est conduite par une réflexion sur les dispositifs hypertextuels, dans le cadre de l'étude des activités cognitives impliquées
dans la lecture et la compréhension, au travers de l'analyse de parcours de lecture et de la construction de sens par ces parcours.
Notre analyse porte également sur les modalités de construction des bibliothèques numériques, combinant les aspects techniques et patrimoniaux.
Ouici, Houria. "Propositions pour une représentation schématisée de connaissances encyclopédiques". Lyon 3, 2002. http://www.theses.fr/2002LYO33012.
Pełny tekst źródłaDuclos, Anne-Marie. "Méthodologies de représentation des connaissances appliquées à l'automatique". Vandoeuvre-les-Nancy, INPL, 1990. http://www.theses.fr/1990INPL071N.
Pełny tekst źródłaChen, Ziqiang. "Représentation et gestion de connaissances temporelles et incertaines". Paris 11, 1993. http://www.theses.fr/1993PA112099.
Pełny tekst źródłaGrandemange, Philippe. "Représentation des connaissances et profondeur variable : une implantation". Paris 13, 1992. http://www.theses.fr/1992PA132008.
Pełny tekst źródłaKiss, Adorjan. "Uniscript : un modèle de représentation de connaissances pérennes". Montpellier 2, 2005. http://www.theses.fr/2005MON20187.
Pełny tekst źródłaOtmani, Nassim Abdeldjallal. "Modélisation ontologique pour l'acquisition et la représentation progressives des connaissances". Thesis, Toulouse 2, 2019. http://www.theses.fr/2019TOU20098.
Pełny tekst źródłaEach discipline, to some extent, has its own jargon used by experts to describe unambiguously the concepts of a particular domain. This jargon allows experts to communicate effectively and accurately. Efficiency offers the possibility of describing a concept with a single term or expression instead of adding a whole definition. Accuracy reduces the risk of misunderstanding by accurately describing the desired concept. For example, specialized medical terminologies allow doctors to write symptoms or diseases on a patient file. On the other hand, it is not easy for people who are not familiar with the domain to master this jargon. Ontologies make it possible to represent all the concepts of a domain, and the terminologies associated with them. This thesis presents an approach to solving the problem of divergence of knowledge between layman users and experts by leveraging domain ontologies
Escamilla, de los Santos José Guadalupe. "Shood : un modèle méta-circulaire de représentation de connaissances". Grenoble INPG, 1993. http://tel.archives-ouvertes.fr/tel-00005126.
Pełny tekst źródłaMazière, Pierre. "Les fonctions biologiques moléculaires : représentation et modélisation des connaissances". Montpellier 1, 2004. http://www.theses.fr/2004MON13520.
Pełny tekst źródłaKaci, Souhila. "Connaissances et préférences : représentation et fusion en logique possibiliste". Toulouse 3, 2002. http://www.theses.fr/2002TOU30029.
Pełny tekst źródłaMerabti, Adila Amaria. "Représentation de l'évolution des connaissances : application au domaine biomédical". Rouen, 2015. http://www.theses.fr/2015ROUES025.
Pełny tekst źródłaThe knowledge in the field of health are constantly evolving as well as the resources which allow to model them and the needs of users for which they were built. In fact, this fast knowledge evolution requires an update of corresponding medical documents what motivated many research works. The objective of this work was to propose a generic comparison approach in order to study the evolution between two different versions of same medical document. The comparison approach proposed is based on the extraction of noun phrases and the similarity measures and the mappings between terminologies. This approach was applied on different types of medical documents to evaluate its advantages and limits : documents relative to diseases and more exactly to chronic diseases (example of the French Clinical Practice Guidelines), in which knowledge evolution plays a major role since any small change will strongly impacts their monitoring, and documents about drugs (example of the French Summary of Product Characteristics), to know for example the new changes in the compositions of drugs or the new adverse effects of these drugs
Arab, Mabrouka Sabiha. "Représentation des connaissances dans la logique trivalente de Lukasiewicz et structuration des bases de connaissances". Grenoble 2, 1993. http://www.theses.fr/1993GRE21006.
Pełny tekst źródłaThis work concerns uncertain and incomplete knowledge representation in three-valued logic of lukasiewicz and knowledge base management system based on coupling dbms and expert system. We compare three-valued logic of lukaciewicz with the classical one and with three-valued logics of kleene and bochvar. Propositional and predicate calculus are presented. By studing skolemisation of three-valued formulas and adaptation of the robinson's theorem proving, we obtain the procedure for passing to logic programming. The hypothese of incomplete knowledge invalidate the hypothese of closed world, in consequence, we define a non-monotonic rule for the resolution of goals as "it exists on x such that not (p(x)". The choosen approach needs three steps : construction of a negatif program, resolution of the negatif goal in this program and resolution of the positif program, resolution of the negatif goal in this program and resolution of the positif goals using the classical rule of negation as failure. Following mcdermott's approach, we extend three-valued logic of lukasiewicz to a non-monotonic one by giving a second non-monotonic inference rule. The resulting system guarantees a non-monotonic extension existence, which is not the case in mcdermott's approach. Unicity of this extension is not verified. So, we propose knowledge base structuration to describe different world. This structuration
Würbel, Eric. "Révision de connaissances géographiques". Aix-Marseille 1, 2000. http://www.theses.fr/2000AIX11049.
Pełny tekst źródłaRamon, Sébastien. "Méthodes permettant la prédominance de connaissances subsumées". Thesis, Artois, 2011. http://www.theses.fr/2011ARTO0405/document.
Pełny tekst źródłaThis thesis is in line with the symbolic Artificial Intelligence domain. It deals with a fondamental issue of the logic-based knowledge and reasoning representation. Most particulary, this thesis is interested in the issue occurring when a piece of information is added to a knowledge set which already entails it. How to make sure that this new piece of information prevails the ones that allow its inference? Suppose for instance that a premisses set contains the piece of information “If the switch is on then the room is lighted”. It is natural to expect that adding an additional rule, in a way more precise than the first one, and which assert that “If the switch is on and if the lamp bulb is not broken then the room is lighted”, could prevail it. Indeed, it will not be sufficient to know that “The switch is on” to conclude that “The room is lighted”: it is now necessary that “The lamp bulb is not broken”. Let us note that the second rule is consistent with the first one and that the non monotonic logics and beliefs revision or update frameworks do not handle this issue in principle. First of all, we adress this issue in the classical logic framework, and secondly in a most general framework of non monotonic logic based representation, and particulary the ones that allow the representation of rules with exceptions subject of consistency test
Faron-Zucker, Catherine. "Connaissances taxinomiques : représentation et taxinomies comportant des exceptions et construction d'hypermédias à base de connaissances taxinomiques". Paris 6, 1997. http://www.theses.fr/1997PA066326.
Pełny tekst źródłaAfyouni, Imad. "Représentation et Gestion des Connaissances dans les Environnements Intérieurs Mobiles". Phd thesis, Université de Bretagne occidentale - Brest, 2013. http://tel.archives-ouvertes.fr/tel-00956812.
Pełny tekst źródłaGratzmuller-Salamitou, Nicole. "Essai sur la représentation des connaissances en droit, structures conceptuelles". Paris 1, 1986. http://www.theses.fr/1986PA010287.
Pełny tekst źródłaMarquesuzaa, Christophe. "Omage : outils et méthode pour la spécification des connaissances au sein d'un atelier de génie éducatif". Pau, 1998. http://tel.archives-ouvertes.fr/docs/00/02/60/09/PDF/Marques-OMAGE.pdf.
Pełny tekst źródłaBressan, Stéphane. "Représentation et modélisation des connaissances : Möbius, un modèle intégrant les aspects conceptuels et déductifs". Lille 1, 1992. http://www.theses.fr/1992LIL10042.
Pełny tekst źródłaLotin, Paul. "Représentation de connaissances complexes : Un formalisme à base de rôles sémantiques". Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 1995. http://tel.archives-ouvertes.fr/tel-00536060.
Pełny tekst źródłaLefrançois, Maxime. "Représentation des connaissances sémantiques lexicales de la Théorie Sens-Texte : conceptualisation, représentation, et opérationnalisation des définitions lexicographiques". Phd thesis, Université Nice Sophia Antipolis, 2014. http://tel.archives-ouvertes.fr/tel-01071945.
Pełny tekst źródłaBarros, Maria Betânia. "Système de représentation de connaissances tacites : le cas de la stratégie dans un secteur d'énergie". Lyon 3, 2010. https://scd-resnum.univ-lyon3.fr/out/theses/2010_out_barros_m.pdf.
Pełny tekst źródłaIn the current context of competition based on knowledge, to take action against uncertainties demands companies to seek a better knowledge of themselves, their strengths and weaknesses and the development of a greater capacity for risk management. Analysing the electrical energy sector as an industry, all planning and operational decisions should be inserted within a national context. We present a proposal for strategic analysis developed by a group of specialists in the area of knowledge and client management from the company Eletropaulo, Brasil. Adopting a constructivist methodology, the study analyses the relationship between strategic actions, innovative practices and the environmental context, describing the main initiatives of the decision makers in collaborative and competitive activities. The study encompasses the aspects of innovative practices that vary from unstructured internal activities to organisation of interactions with external counterparties. Attention is directed towards the internal and external actors and to the mechanisms they have created with regards to the establishment of agreements for the development of new technologies and to generate new markets. Our objective was to improve the innovation process through the management of tactical and explicit knowledge taking all the intra-organisational competencies into account. The main result resides in the identification of characteristics of the creative process, influenced by the potential contribution of tactical knowledge, as a resource for a company to gain comparative advantage
Gensel, Jérôme. "Contraintes et représentation de connaissances par objets : application au modèle Tropes". Phd thesis, Université Joseph Fourier (Grenoble), 1995. http://tel.archives-ouvertes.fr/tel-00005046.
Pełny tekst źródłaDameron, Olivier. "Modélisation, représentation et partage de connaissances anatomiques sur le cortex cérébral". Rennes 1, 2003. http://www.theses.fr/2003REN1B077.
Pełny tekst źródłaBoldini, Pascal. "Contributions de la théorie des catégories à la représentation des connaissances". Rennes 1, 1995. http://www.theses.fr/1995REN10037.
Pełny tekst źródłaBelouaer, Lamia. "Représentation de la connaissance spatiale pour la planification". Caen, 2011. http://www.theses.fr/2011CAEN2070.
Pełny tekst źródłaWe are interested in the integration of spatial information for representation and reasoning to plan a mission in the human-robot interaction case. The first part of our work is for representation and spatial reasoning. We propose a spatial ontology: SpaceOntology qualitative and quantitative representation and reasonning. Based on this spatial modeling we have implemented a planner with two modules: a module for symbolic reasoning supported by a task planner and a module for spatial reasoning supported by the path planning and SpaceOntology. The third part of our contributions is the extension of the PDDL planning language to spatial information. This extension permits to express spatial planning problems
Madani, Nacéra. "Etude de l'héritage des propriétés dans les réseaux sémantiques : Notion de réseau d'héritage légal". Paris 13, 1994. http://www.theses.fr/1994PA132016.
Pełny tekst źródłaCourdier, Rémy. "Représentation des connaissances pour les diagnostics de dysfonctionnements de systèmes intégrés de production". Nice, 1993. http://www.theses.fr/1993NICE4638.
Pełny tekst źródłaCori, Marcel. "Modèles pour la représentation et l'interrogation de données textuelles et de connaissances". Paris 7, 1987. http://www.theses.fr/1987PA077047.
Pełny tekst źródłaTraore, Mamadou. "Modélisation et représentation de connaissances médicales : Contribution aux projets AIDE et SATIN". Compiègne, 1997. http://www.theses.fr/1997COMP996S.
Pełny tekst źródłaThe overall objective of the AIDE (Architecture Integrating Deduction and Explanation) project - within which this thesis work has been done - is to study and deve!op a high level knowledge representation language which, on the one hand, facilitates the operationalisation of KADS-like models of expertise and, on the other hand, enables to design Knowledge Based Systems capable to explain their behaviour of problem-solving and to evaluate their own performances. Ln this context, we addressed medical knowledge modelling and representation in the framework of the development of the medical Expert System SATIN. Our contribution is twofold: regarding both modelling and representation aspects. It relies at an ontological level, on the distinction between objects and concepts, the latter being assimilated to meta-objects. A concept or meta-object corresponds to the idea a rational agent has about an object or a class of objects. Taking into account this distinction, we made some extensions on the knowledge representation language AIDE rendering it "strongly intensional". Thus, it allows to render an account of the meaning of concepts and to reason about concepts considered as objects in their own right. Thereafter, we applied these new modelling principles to SATIN, an Expert System for Neonatal Decision Making in the field of newborn's infections. The object level has been used to model a physiological system whereas the concept level has been used to model' a diagnostic reasoning on such a system. Therefore problem-solving concepts such as "sign" and "syndrome" have been modeled as roles played by concepts. Sample runs of SATIN on clinical cases illustrate the contribution of our work
Bronner, Gisèle. "Représentation des connaissances en cartographie comparée des génomes : le modèle de GeMCore". Lyon 1, 2002. http://www.theses.fr/2002LYO10045.
Pełny tekst źródłaFaci, Adam. "Représentation, simulation et exploitation de connaissances dans le formalisme des graphes conceptuels". Electronic Thesis or Diss., Sorbonne université, 2022. http://www.theses.fr/2022SORUS419.
Pełny tekst źródłaThis thesis addresses the field of knowledge representation in conceptual graphs, a structured knowledge representation formalism that provides efficient manipulation tools. There are many challenges in symbolic artificial intelligence concerning the representation of knowledge in general, and in particular the concise representation of a large amount of information. Conceptual graphs, by their ability to visually represent different kinds of knowledge, mainly ontological and factual, and by offering efficient manipulation tools, provide a perfect framework for the answer to these problems. We conduct a comparative study of fuzzy extensions of conceptual graphs, then we propose an algorithm for conceptual graphs simulation as well as an efficient algorithm for extracting frequent patterns that are not redundant with ontological knowledge
Fürst, Frédéric. "Contribution à l'ingénierie des ontologies : une méthode et un outil d'opérationalisation". Nantes, 2004. http://www.theses.fr/2004NANT2055.
Pełny tekst źródłaOntology engineering aims at building and using ontologies, that are knowledge representations of a domain independent of any operational uses. In this context, this thesis deals with the study of the operationalisation of domain ontology, that is process which allows to transcribe the conceptual knowledge representation of an ontology, neutral towards the uses, into an operational representation, appropriate to its use in a Knowledge-Based System (KBS). We clarify the notion of operationalisation of ontology and we propose a general operationalisation methodology by specifying the scenario of use of the KBS. We also propose a language to express ontologies in the context of the Entity/Relationship paradigm, language inspired by the Conceptual Graphs model (CGs). Our language is dedicated to the representation of heavy-weight ontologies that contain the terminological knowledge of a domain (concepts and relations) and axioms that express the semantics of the domain. We apply our methodology to this language and we define formal operationalisation rules that allow to automatically transcribe an ontology, expressed in our langage, into the CGs model. These rules are implemented in a tool named TooCoM, which allows to edit ontologies in our langage, to operationalise ontologies in the CGs model, to reason with the operational ontologies produced in the tool and to test and match ontologies
Malanda, Urbain Maxime. "Connaissance et représentation de connaissances en droit interne des contrats et des obligations : de l'analyse conceptuelle à la banque de données juridiques et au recueil, outils de connaissances". Montpellier 1, 2000. http://www.theses.fr/2000MON10038.
Pełny tekst źródłaCarré, Bernard. "Méthodologie orientée objet pour la représentation des connaissances : concepts de point de vue, de représentation multiple et évolutive d'objet". Lille 1, 1989. http://www.theses.fr/1989LIL10018.
Pełny tekst źródłaSmaïl-Tabbone, Malika. "Raisonnement à base de cas pour une recherche évolutive d'information : prototype cabri-n : vers la définition d'un cadre d'acquisition de connaissances". Nancy 1, 1994. http://www.theses.fr/1994NAN10409.
Pełny tekst źródłaWozniak, Adrianna. "La théorie évolutive de la connaissance. La relation phylogénétique de la représentation à l'objet". Lyon 3, 2006. https://scd-resnum.univ-lyon3.fr/out/theses/2006_out_wozniak_a.pdf.
Pełny tekst źródłaDans ma thèse j'examine l'hypothèse affirmant qu'il existe des représentations synthétiques a priori (innées), non accessibles au contrôle du sujet (Représentations Acquises Phylogénétiquement, RAP), et que ces représentations proviennent de relations causales sélectives entre l'organisme et certains facteurs de l'environnement phylogénétique; la genèse adaptative des RAP leur procurerait le statut de connaissance. La validité de cette hypothèse est analysée à travers l'étude critique des concepts principaux de la Théorie Synthétique de l'Evolution, tels que le concept du gène, de la causalité génétique, de l'unité de sélection, de l'espèce ; le concept de l'information ; le concept de l'inné. J'examine des suppositions métaphysiques sous-tendant la pratique taxinomique. Enfin, j'introduis la Théorie Relativiste de l'Evolution, inspirée par la théorie du constructivisme évolutif (R. Lewontin) et par la théorie de la construction de niche (Niche Construction de J. Odling-Smee), rompant avec la modélisation externaliste de la relation environnement/organisme propre à la Théorie Synthétique de l'Evolution
Sellini, Florence. "Contribution à la représentation et à la vérification de modèles de connaissances produit en ingénierie d'ensembles mécaniques". Châtenay-Malabry, Ecole centrale de Paris, 1999. http://www.theses.fr/1999ECAP0616.
Pełny tekst źródłaRaimbault, Thomas. "Transition de modèles de connaissances - Un système de connaissance fondé sur OWL, Graphes conceptuels et UML". Phd thesis, Université de Nantes, 2008. http://tel.archives-ouvertes.fr/tel-00482664.
Pełny tekst źródłaKeita, Abdel Kader. "Conception coopérative d'ontologies pré-consensuelles : application au domaine de l'urbanisme". Lyon, INSA, 2007. http://theses.insa-lyon.fr/publication/2007ISAL0030/these.pdf.
Pełny tekst źródłaAn ontology has two different definitions according to the field of interest, in fact philosophy or computer science: From the philosophical point of view, an ontology is defined as being the science of what exists. From the point of view of computer science and more particularly, knowledge engineering, the definition most commonly accepted is that of (Studer, 1998) : "an ontology is an explicit formal specification of a shared conceptualization of a field ". The majority of works and the existing tools relate to the creation of ontologies, once the consensus is carried out (which we entitle as post-consensual ontologies). Thus, one of the key stages in the process of developing an ontology is the consensus between the various actors. But the principal problem is how to reach this consensus. One of the essential characteristics of ontologies is that they provide consensual data on a given field. Nowadays, ontologies include a so rich set of knowledge that their full comprehension exceeds that of any single developer or creator or even that of a small team of creators. The development of an ontology on a large scale must be the result of a joint effort from several experts in various fields and software developers. So the collaborative approach for the development of ontology is best adapted for this task compared to the other non collaborative approaches, because of the characteristics, themselves, of an ontology. However the majority of the methods and methodologies do not propose recommendations to reach the consensus when ontologies are built with a collaborative way. The construction of ontologies with a collaborative environment was and remains a continuous and open subject of research. There exists a certain number of tools for the collaborative development of ontologies. But none offers a complete and adaptable support for all the requirements of the collaborative development. The analysis of the existing tools and groupware products (for the collaborative development of ontologies) does not check only the fact that the collaborative development is the inherent nature of the design of ontology, but also states that the collaborative development of ontology is well supported by none of the existing tools or environments. This presents a new challenge to find tools better adapted for the collaborative development of ontology. The inexistence (as we know) of ontology for urban planning and regional planning, as well as the complexity and the dimension of the domain of urban planning add a particular interest to this challenge. Contributions In contrast of the majority of research works and existing tools which relate to the creation of ontologies once the consensus is carried out post-consensual ontologies), our research works, produced in the context of the European project TOWNTOLOGY, focus on the first phases of development of an ontology, when the consensus is not yet reached. This work tries to answer the question of reaching the consensus by proposing a methodology to create a pre-consensual ontology on the basis of the opinions of various actors. For example, we insist on the need for keeping various definitions for the same concept
Laudy, Claire. "Fusion multi-sources d'informations de haut niveau : introduction de connaissances sémantiques pour la gestion des incohérences". Paris 6, 2010. http://www.theses.fr/2010PA066199.
Pełny tekst źródłaKinkielele, Dieudonné. "Vérification de la cohérence des bases de connaissances floues". Chambéry, 1994. http://www.theses.fr/1994CHAMS029.
Pełny tekst źródłaFaure, Nicolas. "Un système d'aide à la modélisation des connaissances en géotechnique". Lyon 3, 2007. https://scd-resnum.univ-lyon3.fr/in/theses/2007_in_faure_n.pdf.
Pełny tekst źródłaThis research work deals with the conception and the realisation of a computer tool prototype, destined to allow representation and use of geotechnical knowledge ; seen as the interaction between the ground and a building. Geotechnical knowledge and its specificities are first detailed, then various ways of knowledge representation are exarnined at the light of said specificities. Ontological representation is favoured for its terminological dimension, adapted to the fact that geotechnical knowledge is to be extracted from documents. An analysis of the way a domain conceptualization can be built is then proposed, which leads to the conclusion that concepts extracted from documents should be contextualized. To this end, we use a knowledge component, designed after a discourse representation theory. This component can be stocked and aggregated to other components in order to allow the user to build a useful model. Presentation of the prototype ends the document
Schang, Daniel. "Représentation et interprétation de connaissances spatiales dans un système de dialogue Homme-Machine". Nancy 1, 1997. http://docnum.univ-lorraine.fr/public/SCD_T_1997_0009_SCHANG.pdf.
Pełny tekst źródłaFuchs, Béatrice. "Représentation des connaissances pour le raisonnement à partir de cas : le système ROCADE". Saint-Etienne, 1997. http://www.theses.fr/1997STET4017.
Pełny tekst źródłaBinse, Michel. "Représentation de connaissances et complexité de Kolmogorov : le cas du dessin au trait". Lille 1, 1994. http://www.theses.fr/1994LIL10129.
Pełny tekst źródłaMarrakchi, Maledh. "Représentation des connaissances pour l'aide au diagnostic industriel : application au système expert S.E.DIAG". Valenciennes, 1986. https://ged.uphf.fr/nuxeo/site/esupversions/2e0d283c-3b03-4afb-981b-a5886a86ee0e.
Pełny tekst źródłaValtchev, Petko. "Construction automatique de taxonomies pour l'aide à la représentation de connaissances par objets". Université Joseph Fourier (Grenoble), 1999. http://www.theses.fr/1999GRE10276.
Pełny tekst źródłaBentolila, Simone. "La logique et le vivant : les formalismes de représentation des connaissances en biologie". Marne-la-Vallée, 2002. http://www.theses.fr/2002MARN0144.
Pełny tekst źródłaThe problem of modeling biological knowlege has become acute. Now that the human genome has been sequenced and the modeling of the logic for gene recognition has progressed, the next question to be answered is that of the logic of the regulatory mechanisms and the circulation of information via protein interactions in the cell, between cells of the same tissue and then at the organism level. Indeed, regulatory mechanisms favour one pathway, a single path in the network of possible reactions, all of which are probable, but the pathway to which the cell commits is activated by regulatory proteins and/or the environment. The DNA database contains the matrix for the translation of genes into proteins; the "know-how" is based on the genetic code, but the regulatory mechanisms indicate "what to do" in a given cellular and tissular environment, aided by algorithmic notions of alternatives and recursiveness. The grammar that we present is a modelization of regulatory mechanisms for gene expression that considers two types of objects: DNA transcriptional units and the proteins synthesized, and other regulatory molecules and ligands. The molecular algebra describes the succession of operations for the four systems of regulation: by activation or repression, each of which may be modulated by a positive or negative cofactor. The object of the simulation is the observation of the cell in a given state, and for a given process which implicates a cascade of genes; the examples of biological algorithms tested combines several types of regulation: the lactose operon, regulation of metallothionein, catabolism of galactose in yeast, the tryptophan operon and passage from the lysogenic to the lytic phase in phage. This model has been extended to intercellular communications as well as regulatory mechanisms for metabolic pathways. We present two examples of biological algorithms at the organismic scale: a simplified description of the immune response and glycogen metabolism in the liver. A demonstration of this has recently been performed by experiments in "re-programming" of the nucleus by the cytoplasm of another cell, a stem cell or a mature ovum, with therapeutic or cloning objectives. The two key concepts of this re-programming are the molecular algebra of regulatory mechanisms and the working-space memory of the cell in which vital biological processes take place