The paper introduces a framework whereby arguments put forward in a discussion concerning a specific decision can be graphically represented as a directed graph and analysed according to different decision procedures. The intended benefits of the proposed framework are to support a decision manager in the light of the experts' arguments and to record the motivations for the decisions in a corporate memory.

This paper studies the notion of information evaluation in fusion. It starts from some recommendations defined by NATO relatively to information evaluation in intelligence. It shows that these recommendations, even if imprecise and ambiguous, point out three notions which should be taken into account in order to define information evaluation. It proposes a model of information evaluation, which takes into account these notions and an associated fusion process as well.

This paper proposes a discussion on the formal links between the situation calculus and the semantics of interpreted systems as far as they relate to higher-level information fusion tasks. Among these tasks situation analysis require to be able to reason about the decision processes of coalitions. Indeed in higher levels of information fusion, one not only need to know that a certain proposition is true (or that it has a certain numerical measure attached), but rather needs to model the circumstances under which this validity holds as well as agents' properties and constraints. In a previous paper the authors have proposed to use the interpreted system semantics as a potential candidate for the unification of all levels of information fusion. In the present work we show how the proposed framework allow to bind reasoning about courses of action and situation awareness. We propose in this paper a (1) model of coalition, (2) a model of ability in the situation calculus language and (3) a model of situation awareness in the interpreted systems semantics. Combining the advantages of both situation calculus and the interpreted systems semantics, we show how the situation calculus can be framed into the interpreted systems semantics. We illustrate on the example of RAP compilation in a coalition context, how ability and situation awareness interact and what benefit is gained. Finally, we conclude this study with a discussion on possible future works.

The problem of combining pieces of information issued from several sources can be encountered in various fields of application. This paper aims at presenting the different aspects of information fusion in different domains, such as databases, regulations, preferences, sensor fusion, etc., at a quite general level. We first present different types of information encountered in fusion problems, and different aims of the fusion process. Then we focus on representation issues which are relevant when discussing fusion problems. An important issue is then addressed, the handling of conflicting information. We briefly review different domains where fusion is involved, and describe how the fusion problems are stated in each domain. Since the term fusion can have different, more or less broad, meanings, we specify later some terminology with respect to related problems, that might be included in a broad meaning of fusion. Finally we briefly discuss the difficult aspects of validation and evaluation. © 2001 John Wiley & Sons, Inc.

This paper focuses on databases merging, which is one particular case of data fusion. Databases merging is the process which consists of integrating, physically or virtually, the data provided by several databases. With examples throughout the paper, we stress the main problems raised by databases merging and we present, not exhaustively, some solutions. The topics receiving deepest study are: cases matching, inconsistency handling and summarizing data. © 2001 John Wiley & Sons, Inc.

It often happens that organizations or companies have to respect several regulations simultaneously. Here, we analyze a practical example which applies to the context of documents containing sensitive information. This example considers the problem of downgrading the classification of these documents when their contents become obsolete. There are several regulations that deal with this problem and it appears that these regulations are conflicting. In this article, we suggest a general approach to detect and solve the conflicts between the regulations and show how it applies to our practical example. © 2001 John Wiley & Sons, Inc.

It often happens that organizations or companies have to respect several security policies simultaneously. The authors analyze a practical example which applies to the context of documents containing sensitive information. This example considers the problem of downgrading the classification of these documents when their contents become obsolete. There are several security policies that deal with this problem and it appears that these security policies are conflicting. They suggest a general approach to detect and solve the conflicts between the security policies and show how it applies to the practical example.

In this paper, we are interested in formally modeling the concept of responsibility.It appears that this concept is essential in order to reason in many norm-governed organizations.However, obtaining a formal representation of responsibility is quite complex because of the very different meanings this concept can take.Therefore, our first task will be to clarify and classify the various meanings.We then propose a logical framework and show how it enables us to model several aspects of responsibility, This framework combines a deontic logic with a logic of actions and it distinguishes between direct and indirect agencies.We finally present an example to illustrate how this framework enables us to analyze some subtleties of a specific situation.

We discuss the development of a methodology for reasoning about properties of security policies. We view a security policy as a special case of regulation which specifies what actions some agents are permitted, obliged or forbidden to perform and we formalize a policy by a set of deontic formulae. We first address the problem of checking policy consistency and describe a method for solving it. The second point we are interested in is how to query a policy to know the actual norms which apply to a given situation. In order to provide the user with consistent answers, the normative conflicts which may appear in the policy must be solved. For doing so, we suggest using the notion of roles and define priorities between roles.

This paper addresses the problem of conflicting norms.The solution we describe is based on the concept of role: a role defines some permissions, obligations and prohibitions which are supposed free of conflicts.As soon as an individual plays a role, he inherits the set of norms associated with this role.We show that conflicting norms arise because an individual may play different roles.The central idea of our paper is to consider that it is possible to make a judgement of priority between the roles an individual plays, in order to decide which are the actual norms which apply in a given situation.This priority may be chosen by the individual or may be dependent on the structure which may exist between roles.Our paper mainly describes the axiomatic part of a logic for reasoning about norms associated with primitive roles as well as with composite roles obtained by merging several roles.

This paper deals with database updates. More precisely we focus on addition and deletion operations, when transition constraints are expressed on the database. In the first section, we present an overview of works in the fields of belief revision, knowledge base and database updates. We claim that database update semantics is a formulas-based (or syntactical) one. Furthermore, we pay attention to the notion of transition constraints, introduced in the database domain many years ago in order to constrain state changes. In the second section, we present the formalism we think necessary to express transition constraints and reason with them. It is a particular modal formalism which allows us to reason with the current state of the database and with its next state as well. In Sections 3 and 4, we intend to characterize the database state that follows from an addition or a deletion, taking transition constraints into account. We give importance to a notion of minimal change which extends the classical notion of minimal change on finite bases. We show that, when no transition constraint is expressed, the semantics we give to the addition (resp.: deletion) is a maxichoice one. We also focus on another particular case of transition constraints which could allow us to computationally generate the next database state. Then we discuss the problem of extending these cases to the general one. © 1994 John Wiley & Sons, Inc.