Catálogo de publicaciones - libros

A multi-agent system can be analyzed and specified as an organization consisting of roles and their relations. The performance of an organization depends on many factors among which the type of its organizational structure, i.e., the set of relations holding between its roles. This work focuses on the structure of organizations and addresses the issue of the analysis, evaluation, and comparison of organizational structures which can contribute to develop general methods for the assessment of multi-agent systems’ performance. Specifically, quantitative concepts from graph theory are used to provide numerical analyses of organizational structures. It is argued that these analyzes can be used for evaluating to what extent an organizational structure exhibits some characteristic properties such as robustness, flexibility and efficiency.

Organisational models cannot only be used to structure multiagent systems but also to express behaviour constraints for agents in open environments. However, sometimes these behaviour constraints cannot be exhaustively enforced, and some agents may transgress the norms put forward by a Virtual Organisation. This poses an additional burden on agents, as they cannot be sure that their acquaintances will behave as prescribed. Trust and reputation mechanisms are of particular relevance to this respect, as they are commonly used to infer expectations of future behaviour from past interactions.

In this paper we argue that, on the one hand, the a priori structure of Virtual Organisations can be useful to improve the efficiency of trust and reputation mechanisms, and that, on the other hand, such mechanisms provide relevant information for agents that are part of Virtual Organisations. For this purpose, we identify relevant aspects of existing organisational (meta-)models, and outline a reputation mechanism for Virtual Organisations that integrates these aspects. The dynamics of this mechanism is illustrated by an example.

Support for new forms of organization and social interaction requires understanding the influence of structure on behavior. Goal dependencies indicate some relationship between roles, through which actions can be coordinated. Social relationships determine different types of power links between roles. Efficient coordination requires that goal dependency and power structure are well tuned to each other. In this paper, we will investigate what is the exact nature of this relationship between roles in an organization and what are the consequences of different structure forms. We will also see what is the difference if the relations are not hierarchical but organized through a market or network structure.

Artificial Intelligence has contributed (formal) design models and software support tools to application areas such as architecture, engineering and software design This paper explores the effectiveness of applying design models to the area of organization (re)design. To that purpose a component-based model for (re)design of organizations is presented as a specialization of an existing generic design model. Using recently developed formalizations within Organization Theory organization models are described as design object descriptions, and organization goals as design requirements. A design process specification is presented that models the redesign process for an organization that adapts to changes in the environment. The formally specified and implemented approach to organization redesign thus obtained has been tested for a well-known historical case study from the Organization Theory literature.

Correctly specifying the behaviour of normative systems such as contracts and institutions is a troublesome problem. Designers are faced with two concurrent, difficult tasks: firstly specifying the relationships (over time) of agents’ actions and their effects, and secondly combining this model with another that captures the agents’ permissions and obligations. In this paper we present our model and operational semantics for specifying individual and collective institutions and outline a declarative action language for describing them. We demonstrate, by way of an example, how this may be used to enable the analysis of institutional specifications either for simply visualising possible outcomes or for checking for absence or presence of certain (un)desirable correctness properties.

Interactive multimedia applications are whelming to increase realism in their content and scenes with which users interact. To this aim, autonomous agents are increasingly used to implement the objects composing the scene. Although autonomy brings flexibility and realism in the animation, it has to be controlled in order to conform to the global behaviour targeted by the designer of the application. Multi-agent based organisational models are good candidates to specify “rights” and “duties” of agents with respect to the intended behaviour. In this paper we present , a meta-model aiming at representing normative organisations of agents according to four points of view: structural, functional, contextual and normative. We show how this model is suited to control an application of interactive TV game show where avatars are based on agents.

The viability of the application of the e-Institution paradigm for obtaining overall desired behavior in open multiagent systems (MAS) lies in the possibility of bringing the norms of the institution to have an actual impact on the MAS. Institutional norms have to be in the society. The paper addresses two possible views on implementing norms, the so-called of norms, and the of norms, with particular attention to this last one. Aim of the paper is to provide a theory for the understanding of the notion of enforcement and for the design of enforcement mechanisms in e-Institutions.

Institutions have been proposed as a means to regulate open interaction systems by introducing a set of norms (involving deontic positions like authorizations, obligations, prohibitions, and permissions) and to define the ontology of the context in which agents interact. To better clarify the interdependence existing among deontic positions and the ontology defined by each institution, in this paper we propose to model institutions in terms of status functions imposed on agents and defined as aggregates of deontic positions. We present a metamodel which describes the concepts necessary to specify an institution and FIEVeL, a language that can be used to formalize institutions. Finally, we discuss how to automatically translate FIEVeL specifications into the input language of the SPIN model checker and the kind of properties that it is possible to check.

Organisational structures for multi-agent systems are usually defined independently of any spatial or temporal structure. Therefore, when the multi-agent system is situated in a spatial environment, there is usually a conceptual gap between the definition of the system’s organisational structures and the definition of the environment. In this paper, we focus on a mechanism for the spatial distribution of an organization’s normative information. Spatially distributing the normative information over the environment is a natural way to simplify the definition of organisational structures and the development of large-scale multi-agent systems. By distributing the normative information in different spatial locations, we allow agents to directly access the relevant information needed in each environmental context. We extend our previous work on a language for modelling multi-agent environments in order to allow for the definition of spatially distributed norms in the form of .

We believe that, in the near future, all multi-agent systems (MASs) will be open, permitting agents to migrate among MASs to obtain resources or services not found locally. In this scenario, open MASs should be enhanced with norms for restricting agents’ actions and, thus, avoiding unexpected behavior. In this work, we present a case study where an open MAS is enhanced with contextual norms. Agents from this MAS are continuously supported with precise norm information, according to their contexts () and, then, can make better decisions. Although the presented case study is simple, it clearly shows different levels of norm abstractions and how agents can be influenced by norms while acting in a regulated open MASs.