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Detalhes

Detalhes

  • Nome

    Olga Pacheco
  • Cargo

    Investigador Sénior
  • Desde

    01 novembro 2011
Publicações

2006

Normative specification: A tool for trust and security

Autores
Pacheco, O;

Publicação
FORMAL ASPECTS IN SECURITY AND TRUST

Abstract
Many software systems can be viewed as organizational Systems, where the different components are seen as autonomous entities, interacting with each other, collaborating toward system's aims. In such systems we may not have full control over the behavior of all its components. Normative specification of an organizational system, provides a way of describing the norms that regulate the behavior of a system and of its components, stating how they are expected to behave, assuming however, that they may deviate from that ideal behavior. In this paper we use an action and deontic modal logic for the normative specification of organizational systems. This logical framework allows us to describe expected behavior of agents, detect non-ideal behavior and identify the agents that, direct or indirectly, are responsible for it. We argue that normative specification can be an useful tool to increase trust and security in complex computational systems and propose a responsibility-based trust concept.

2004

Autonomy in an organizational context

Autores
Pacheco, O;

Publicação
AGENTS AND COMPUTATIONAL AUTONOMY: POTENTIAL, RISKS, AND SOLUTIONS

Abstract
In this paper it is discussed how organizations deal with autonomy of agents that constitute them. Based on human organizations and on their legal characterization, it is proposed a normative and rolebased model for organizations (human or not), that assumes autonomy of agents as a natural ingredient. It is discussed how an organization can work without regimenting agents behavior, but simply by describing their expected (ideal) behavior (through the deontic characterization of the roles agents hold) and fixing sanctions for agents that deviate from what is expected of them. Interaction between agents is ruled through contracts that agents are free to establish between each other. A formal model, supported by a deontic and action logic, is suggested. Although this model is in a preliminary stage, it might be an useful approach to incorporate autonomy as a natural property of agents in an organizational context.

2004

Delegation in a role-based organization

Autores
Pacheco, O; Santos, F;

Publicação
DEONTIC LOGIC IN COMPUTER SCIENCE, PROCEEDINGS

Abstract
In an organizational context the norms that apply to an agent depend on the roles he holds in the organization. The deontic characterization of structural roles is defined when the organization is created. But an organization is not a static entity. Among the dynamic phenomena that occur in an organization there are interactions between agents consisting in a transference of obligations or permissions from an agent to another. These kind of interactions axe called delegation. In this paper we analyze different ways in which delegation occurs in an organizational context. We argue that the concept of "agent in a role" is relevant to understand delegation. A deontic and action modal logic is used to specify this concept.

2003

A role based model for the normative specification of organized collective agency and agents interaction

Autores
Pacheco, O; Carmo, J;

Publicação
AUTONOMOUS AGENTS AND MULTI-AGENT SYSTEMS

Abstract
In this article we propose a role based model for the specification of organized collective agency, based on the legal concept of artificial person and on the normative perspective of organizational systems. We focus on the analysis of groups of agents ( humans or not) that want to act collectively in a ( more or less) permanent basis, and in a stable and organized way, as it is the typical case of organizations. We argue that in those cases such groups of agents should give rise to a new agent, that we call of institutionalized agent, with its own identity, whose structure is essentially defined through the characterization of a set of roles and whose behavior is determined by the acts of the agents that play such roles. We also present a deontic and action modal logic that captures the concept of acting in a role and relates it with the deontic notions of obligation, permission and prohibition. This logic is used in the formal specification of institutionalized agents and of societies of agents and in the rigorous analysis of them. We pay particular attention to the interaction between agents through contracts or other normative relations. A high level specification language is also suggested.

2001

Deontic and action logics for organized collective agency, modeled through institutionalized agents and roles

Autores
Carmo, J; Pacheco, O;

Publicação
FUNDAMENTA INFORMATICAE

Abstract
In this paper we address the problem of organized collective agency, and propose a deontic/action modal logic for that purpose. We argue that once we want to attribute obligations (permissions or other deontic notions) to a set of agents, we need to consider a new agent-that we called institutionalized agent, and specify how he interacts with the external world: how the obligations flow from the institutionalized agent to the real agents that support him, and how the actions of the latter count as actions of the former. But an agent may act in many qualities (roles), and it is essential to know in which quality an agent has acted, or intends to act, for three main reasons: to know the effects of the act, its deontic qualification, and authentication issues. Thus, we extend the "sees to it" action operator with an explicit index that states the quality (role) in which the agent has acted. We also show how to associate obligations to roles, and illustrate flow this can be used to express the desired flow of obligations.