Communicating open systems

Just as conventional institutions are organisational structures for coordinating the activities of multiple interacting individuals, electronic institutions provide a computational analogue for coordinating the activities of multiple interacting software agents. In this paper, we argue that open multi-agent systems can be effectively designed and implemented as electronic institutions, for which we provide a comprehensive computational model. More specifically, the paper provides an operational semantics for electronic institutions, specifying the essential data structures, the state representation and the key operations necessary to implement them. We specify the agent workflow structure that is the core component of such electronic institutions and particular instantiations of knowledge representation languages that support the institutional model. In so doing, we provide the first formal account of the electronic institution concept in a rigorous and unambiguous way

Roles '07 – Proceedings of the 2nd Workshop on Roles and Relationships in Object Oriented Programming, Multiagent Systems, and Ontologies : workshop co-located with ECOOP 2007 Berlin, July 30 and 31, 2007

Roles are a truly ubiquitous notion: like classes, objects, and relationships, they pervade the vocabulary of all disciplines that deal with the nature of things and how these things relate to each other. In fact, it seems that roles are so fundamental a notion that they must be granted the status of an ontological primitive. The definition of roles depends on the definition of relationships. With the advent of Object Technology, however, relationships have moved out of the focus of attention, giving way to the more restricted concept of attributes or, more technically, references to other ob- jects. A reference is tied to the object holding it and as such is asymmetric – at most the target of the reference can be associated with a role. This is counter to the intuition that every role should have at least one counter-role, namely the one it interacts with. It seems that the natural role of roles in object-oriented designs can only be restored by installing relationships (collaborations, teams, etc.) as first-class programming concepts. By contrast, the relational nature of roles is already acknowl- edged in the area of Multiagent Systems, since roles are related to the interaction among agents and to communication protocols. However, in this area there is no convergence on a single definition of roles yet, and different points of view, such as agent software en- gineering, specification languages, agent communication, or agent programming languages, make different use of roles. Like its pre- decessor “Roles, an interdisciplinary perspective” (Roles’05) held at the AAAI 2005 Fall Symposium (see the website of the Symposium http://www.aaai.org/Press/Reports/Symposia/Fall/fs-05-08.php), this workshop aimed at gathering researchers from different dis- ciplines to foster interchange of knowledge and ideas concerning roles and relationships, and in particular to converge on ontolog- ically founded proposals which can be applied to programming and agent languages

An executable Theory of Multi-Agent Systems Refinement

Complex applications such as incident management, social simulations, manufacturing applications, electronic auctions, e-institutions, and business to business applications are pervasive and important nowadays. Agent-oriented methodology is an advance in abstractionwhich can be used by software developers to naturally model and develop systems for suchapplications. In general, with respect to design methodologies, what it may be important tostress is that control structures should be added at later stages of design, in a natural top-downmanner going from specifications to implementations, by refinement. Too much detail (be itfor the sake of efficiency) in specifications often turns out to be harmful. To paraphrase D.E.Knuth, “Premature optimization is the root of all evil” (quoted in ‘The Unix ProgrammingEnvironment’ by Kernighan and Pine, p. 91).The aim of this thesis is to adapt formal techniques to the agent-oriented methodologyinto an executable theory of refinement. The justification for doing so is to provide correctagent-based software by design. The underlying logical framework of the theory we proposeis based on rewriting logic, thus the theory is executable in the same sense as rewriting logicis. The storyline is as follows. We first motivate and explain constituting elements of agentlanguages chosen to represent both abstract and concrete levels of design. We then proposea definition of refinement between agents written in such languages. This notion of refinement ensures that concrete agents are correct with respect to the abstract ones. The advantageof the definition is that it easily leads to formulating a proof technique for refinement viathe classical notion of simulation. This makes it possible to effectively verify refinement bymodel-checking. Additionally, we propose a weakest precondition calculus as a deductivemethod based on assertions which allow to prove correctness of infinite state agents. Wegeneralise the refinement relation from single agents to multi-agent systems in order to ensure that concrete multi-agent systems refine their abstractions. We see multi-agent systemsas collections of coordinated agents, and we consider coordination artefacts as being basedeither on actions or on normative rules. We integrate these two orthogonal coordinationmechanisms within the same refinement theory extended to a timed framework. Finally, wediscuss implementation aspects.LEI Universiteit LeidenFoundations of Software Technolog

Towards a Dynamic Logic of Gradual Normativity and Norm Adherence

Norms and accountability in multi-agent societies Authors: Kibble, Rodger Norms and plans as unification criteria for social collective