Logics of knowledge and action: critical analysis and challenges

International audienceWe overview the most prominent logics of knowledge and action that were proposed and studied in the multiagent systems literature. We classify them according to these two dimensions, knowledge and action, and moreover introduce a distinction between individual knowledge and group knowledge, and between a nonstrategic an a strategic interpretation of action operators. For each of the logics in our classification we highlight problematic properties. They indicate weaknesses in the design of these logics and call into question their suitability to represent knowledge and reason about it. This leads to a list of research challenges

Global and local graph modifiers

5th Workshop on Methods for Modalities 2007, Cachan, France, 29-30 novembre 2007International audienceWe dene two modal logics that allow to reason about modications of graphs. Both have a universal modal operator. The rst one only involves global modications (of some state label, or of some edge label) everywhere in the graph. The second one also allows for modications that are local to states. The global version generalizes logics of public announcements and public assignments, as well as a logic of preference modication introduced by van Benthem et Liu. By means of reduction axioms we show that it is just as expressive as the underlying logic without global modiers. We then show that adding local modiers dramatically increases the power of the logic: the logic of global and local modiers is undecidable. We nally study its relation with hybrid logic with binder

Optimal methods for reasoning about actions and plans in multi-agent systems

Cet travail présente une solution au problème du décor inférenciel. Nous réalisons cela en donnant une éducation polynomiale d'un fragment du calcul des situations vers la logique épistémique dynamique (DEL). En suite, une nouvelle méthode de preuve pour DEL, dont la complexité algorithmique est inférieure à celle de la méthode de Reiter pour le calcul de situations, est proposée. Ce travail présente aussi une nouvelle logique pour raisonner sur les actions. Cette logique permet d'exprimer formellement "qu'il existe une suite d'action conduisant au but". L'idée étant que, avec la quantification sur les actions, la planification devient un problème de validité. Une axiomatisation et quelques résultats d'expressivité sont donnés, ainsi qu'une méthode de preuve basée sur les tableaux sémantiques.This work presents a solution to the inferential frame problem. We do so by providing a polynomial reduction from a fragment of situation calculus to espistemic dynamic logic (DEL). Then, a novel proof method for DEL, such that the computational complexity is much lower than that of Retier's proof method for situation caluculs, is proposed. This work also presents a new logic for reasoning about actions. This logic allows to formally express that "there exists a sequence of actions that leads to the goal". The idea is that, with quantification over actions, planning can become a validity problem. An axiomatisation and some expressivity results are provided, as well as a proof method based on sematic tableaux

Relation-changing modal operators

We study dynamic modal operators that can change the accessibility relation of a model during the evaluation of a formula. In particular, we extend the basic modal language with modalities that are able to delete, add or swap an edge between pairs of elements of the domain. We define a generic framework to characterize this kind of operations. First, we investigate relation-changing modal logics as fragments of classical logics. Then, we use the new framework to get a suitable notion of bisimulation for the logics introduced, and we investigate their expressive power. Finally, we show that the complexity of the model checking problem for the particular operators introduced is PSpace-complete, and we study two subproblems of model checking: formula complexity and program complexity.Fil: Areces, Carlos Eduardo. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fervari, Raul Alberto. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Hoffmann, Guillaume Emmanuel. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Towards Model Checking Cryptographic Protocols with Dynamic Epistemic Logic

We present a variant of Kripke models to model knowledge of large numbers, applicable to cryptographic protocols. Our Epistemic Crypto Logic is a variant of Dynamic Epistemic Logic to describe com- munication and computation in a multi-agent setting. It is interpreted on register models which eciently encode larger Kripke models. As an example we formalize the well-known Die-Hellman key exchange. The presented register models also motivate a Monte Carlo method for model checking which we compare against a standard algorithm, using the key exchange as a benchmark

Listen to me! Public announcements to agents that pay attention - or not

International audienceIn public announcement logic it is assumed that all agents pay attention (listen to/observe) to the announcement. Weaker observational conditions can be modelled in event (action) model logic. In this work, we propose a version of public announcement logic wherein it is encoded in the states of the epistemic model which agents pay attention to the announcement. This logic is called attention-based announcement logic, abbreviated ABAL. We give an axiomatization and prove that complexity of satisfiability is the same as that of public announcement logic, and therefore lower than that of action model logic [2]. We exploit our logic to formalize the concept of joint attention that has been widely discussed in the philosophical and cognitive science literature. Finally, we extend our logic by integrating attention change

Design and implementation of a software agent platform applied in E-learning and course management

Text in English; Abstract: English and TurkishIncludes bibliographical references (leaves 86-89)xi, 115 leavesIn this thesis, we report an experience on constructing a software agent platform for development and implementation of software agent systems running with integrated e-learning and course management applications which are developed and running under different technologies. The proposed platform consists of an agent development framework namely JADE (Java Agent Development Environmet), a common database infrastructure serving to many different applications and the applications infrastructure running on different platforms. An example e-university application module which is an integrated course management software running on the proposed platform namely Course ON-LINE and an agent application running as an add-on utility to this application namely GAIA is explained in detail to demonstrate the use of the proposed application.Bu çalışmada farklı teknolojiler kullanılarak geliştirilen ve farklı platformlarda çalıştırılmakta olan ve tümleşik yapıdaki uzaktan eğtim ve ders yönetimi araçları uygulamalarla birlikte çalışabilecek yazılım etmen sistemlerinin geliştirilebilmesini sağlayan bir yazılım geliştirme ve çalıştırma ortamı inşa etme deneyimi aktarılmıştır. Önerilen ortam JADE (Java Agent Development Environmet), isimli bir etmen geliştirme aracı, etmen sistemleri dahil tüm uygulamaların ortak kullandıkları bir veritabanı altyapısı, ve farklı ortamlarda çalışan ve farklı teknolojilerle geliştirilmiş uygulamaların altyapısından oluşmaktadır. Önerilen ortamın kullanılışını göstermek için tümleşik ders web sayfaları yönetim aracı olan ve e-üniversite uygulamalarının bir parçası olan Course ON-LINE ve onunla birlikte çalışan bir yazılım etmeni uygulaması olan GAIA uygulamaları detaylıca sunulmuştur