Catálogo de publicaciones - libros

Agent-mediated electronic institutions belong to a new and promising field where interactions among agents are regulated by means of a set of explicit norms. Current implementations of such open-agent systems are, however, mostly using constraints on the behaviour of the agents, thereby severely limiting the autonomy of the agents. In this paper we propose an extension to electronic institutions to allow for a flexible enforcement of norms, and manners to help overcome the difficulties of translating abstract norms for the use of implementation.

Norms constitute a powerful coordination mechanism among heterogeneous agents. We propose means to specify and explicitly manage the normative positions of agents (permissions, prohibitions and obligations), with which distinct deontic notions and their relationships can be captured. Our rule-based formalism includes constraints for more expressiveness and precision and allows the norm-oriented programming of electronic institutions: normative aspects are given a precise computational interpretation. Our formalism has been conceived as a machine language to which other higher-level normative languages can be mapped, allowing their execution.

Hierarchical structures have been widely used by human organizations because they provide the natural means to delegate tasks, to reduce communication lines and to control the activities performed into them. This has motivated the development of different approaches to automate many of the activities that take place in hierarchical organizations. Recent frameworks, such as Gaia, , HarmonIA and OperA, among others, have considered the agent paradigm to do so without taking into account that organizations are dynamic entities that evolve with the time and, consequently, agents must adapt to changes. Here we develop a model for flexible and open hierarchical organizations where agents can dynamically adapt themselves to organizational changes.

We present a case study which describes a ballroom as a social institution with autonomous dancer agents constrained by sets of norms and conventions that coordinate the behaviour of the participants. We provide a representation for the interaction protocols as finite state machines and a new way of formalising the associated norms in a logic programming language. Furthermore, we report on recent and ongoing work on an architecture for normative systems of this kind which allows agents to dynamically download interaction protocols and operational norms to guide their behaviour. Finally, we outline an alternative approach for representing the in a virtual, distributed fashion in the agents’ private belief stores.

Electronic institutions (EIs) have been proposed as a means of regulating open agent societies. EIs define the rules of the game in agent societies by fixing what agents are permitted and forbidden to do and under what circumstances. And yet, there is the need for EIs to adapt their regulations to comply with their goals despite coping with varying populations of self-interested agents. In this paper we focus on the extension of EIs with autonomic capabilities to allow them to yield a dynamical answer to changing circumstances through the adaptation of their norms.

Organisation-oriented approaches to the formation of multi-agent systems use roles and norms to describe an agent’s social position within an artificial society or Virtual Organisation. Norms are descriptive information for a role – they determine the obligations and social constraints for an agent’s actions. A legal instrument for establishing such norms are contracts signed by agents when they adopt one or more roles. A common problem in open Virtual Organisations is the occurrence of conflicts between norms – agents may sign different contracts with conflicting norms or organisational changes may revoke permissions or enact dormant obligations. Agents that populate such Virtual Organisations can remain operational only if they are able to resolve such conflicts. In this paper, we discuss, how agents can identify these conflicts and resolve them.

In this paper, which is exploratory in nature, we introduce how to use Dynamic Electronic Institutions to enable Digital Business Ecosystems. A Digital Business Ecosystem is an evolutionary self-organising system aimed at creating a digital software environment for small organisations. These new forms of networked business require a multi-disciplinary approach based on biology, computer science and social sciences mechanisms and models. Our proposal is to use a multi-agent approach in combination with some social sciences metaphors. More specifically, we propose to imagine the digital environment of business ecosystems as an open agent system, and to study the spontaneous composition and adaptation of the different services and software components, by using Dynamic Electronic Institutions, which we have recently presented in our latest works. In this paper we present a brief summary of our previous work on dynamic institutions, and our first ideas on how to enable Digital Business Ecosystems.

Social order in distributed descentralised systems is claimed to be obtained by using social norms and social control. This paper presents a normative P2P architecture to obtain social order in multi-agent systems. We propose the use of two types of norms that coexist: rules and conventions. Rules describe the global normative constraints on autonomous agents, whilst conventions are local norms. Social control is obtained by providing a non-intrusive control infrastructure that helps the agents build reputation values based on their respect of norms. Some experiments are presented that show how communities are dynamically formed and how bad agents are socially excluded.

This paper uses Participatory Semantics to explicate commitment. Information expresses the fact that a system is in a certain configuration that is correlated to the configuration of another system. Any physical system may contain information about another physical system.

For the purposes of this paper, physical commitment is defined to be information pledgedabout physical systems (situated at a particular place and time). This use of the term physical commitment is currently nonstandard.

Note that commitment is defined for whole physical system; not just a participant or process.

Organizational and social commitments can be analyzed in terms of physical commitments. For example systems that behave as scientific communities can have commitments for monotonicity, concurrency, commutativity, pluralism, skepticism, and provenance.

Speech Act Theory has attempted to formalize the semantics of some kinds of expressions for commitments. Participatory Semantics for commitment can overcome some of the lack of expressiveness and generality in Speech Act Theory.

This paper reports on issues confronted and solutions developed while implementing the author’s previously proposed hyMITL logic for expressing social expectations as conditional rules. A high level overview of hyMITL is presented, along with a discussion of new features and implementation issues. In particular, the importance of using human-oriented descriptions of time points is argued, along with the need to explicitly take time zones into consideration when defining rules, and a syntax for date/time expressions based on ISO standard 8601 is proposed. A new, more detailed, model for tracking the state of social expectations is also presented, based on the utility of enabling clients of a monitoring service to be notified of multiple instances of the violation or fulfilment of an expectation.