References of "van der Torre, Leon 50003247"
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See detailA dynamic logic for privacy compliance
Aucher, Guillaume UL; Boella, Guido; van der Torre, Leon UL

in Artificial Intelligence & Law (2011)

Knowledge based privacy policies are more declarative than traditional action based ones, because they specify only what is permitted or forbidden to know, and leave the derivation of the permitted ... [more ▼]

Knowledge based privacy policies are more declarative than traditional action based ones, because they specify only what is permitted or forbidden to know, and leave the derivation of the permitted actions to a security monitor. This inference problem is already non trivial with a static privacy policy, and becomes challenging when privacy policies can change over time. We therefore introduce a dynamic modal logic that permits not only to reason about permitted and forbidden knowledge to derive the permitted actions, but also to represent explicitly the declarative privacy policies together with their dynamics. The logic can be used to check both regulatory and behavioral compliance, respectively by checking that the permissions and obligations set up by the security monitor of an organization are not in conflict with the privacy policies, and by checking that these obligations are indeed enforced. [less ▲]

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See detailDynamics in Delegation and Revocation Schemes: A Logical Approach
Aucher, Guillaume UL; Barker, Steve; Boella, Guido UL et al

in DBSec (2011)

In this paper we first introduce a logic for describing formally a family of delegation and revocation models that are based on the work in Hagström et al.. We then extend our logic to accommodate an ... [more ▼]

In this paper we first introduce a logic for describing formally a family of delegation and revocation models that are based on the work in Hagström et al.. We then extend our logic to accommodate an epistemic interpretation of trust within the framework that we define. What emerges from this work is a rich framework of formally well-defined delegation and revocation schemes that accommodates an important trust component. [less ▲]

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See detailAttack Semantics for Abstract Argumentation
Villata, Serena; Boella, Guido; van der Torre, Leon UL

in Attack Semantics for Abstract Argumentation (2011)

In this paper we conceptualize abstract argumentation in terms of successful and unsuccessful attacks, such that arguments are accepted when there are no successful attacks on them. We characterize the ... [more ▼]

In this paper we conceptualize abstract argumentation in terms of successful and unsuccessful attacks, such that arguments are accepted when there are no successful attacks on them. We characterize the relation between attack semantics and Dung’s approach, and we define an SCC recursive algorithm for attack semantics using attack labelings. [less ▲]

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See detailA Satisficing Agreements Model
Boella, Guido UL; Pigozzi, Gabriella UL; Slavkovik, Marija UL et al

in Proceedings of the 13th International Workshop on Coordination, Organization, Institutions and Norms (COIN@WI-IAT) (2011)

Satisficing, the concept proposed by Herbert Simon, as an approach to reaching agreements is little explored. We propose a model for satisficing agreement reaching for an adaptive collaborative group of ... [more ▼]

Satisficing, the concept proposed by Herbert Simon, as an approach to reaching agreements is little explored. We propose a model for satisficing agreement reaching for an adaptive collaborative group of agents. The group consists of one human agent familiar with the problem and arbitrarily many artificial agents. Our model raises to the team level the recognition-primed decision model constructed in the field of cognitive decision-making by using social choice for reaching group opinions. [less ▲]

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See detailRules, Agents and Norms: Guidelines for Rule-Based Normative Multi-Agent Systems
Rotolo, Antonino; van der Torre, Leon UL

in RuleML Europe (2011)

In this survey paper we focus on some requirements for developing normative multi-agent systems (NMAS). In particular, we discuss Boella et al.’s guidelines proposed for NMAS. Finally, we deal with two ... [more ▼]

In this survey paper we focus on some requirements for developing normative multi-agent systems (NMAS). In particular, we discuss Boella et al.’s guidelines proposed for NMAS. Finally, we deal with two more specific questions concerning the role of norms in rule-based NMAS: the concepts of compliance and norm change. [less ▲]

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See detailEmbedding Normative Reasoning into Neural Symbolic Systems
Boella, Guido; Colombo Tosatto, Silvano UL; d'Avila Garcez, Artur et al

in Proceedings of the Seventh International Workshop on Neural-Symbolic Learning and Reasoning (2011)

Normative systems are dynamic systems because their rules can change over time. Considering this problem, we propose a neural- symbolic approach to provide agents the instru- ments to reason about and ... [more ▼]

Normative systems are dynamic systems because their rules can change over time. Considering this problem, we propose a neural- symbolic approach to provide agents the instru- ments to reason about and learn norms in a dynamic environment. We propose a variant of d’Avila Garcez et al. Con- nectionist Inductive Learning and Logic Program- ming(CILP) System to embed Input/Output logic normative rules into a feed-forward neural network. The resulting system called Normative-CILP(N- CILP) shows how neural networks can cope with some of the underpinnings of normative reasoning: permissions , dilemmas , exceptions and contrary to duty problems. We have applied our approach in a simplified RoboCup environment, using the N-CILP simula- tor that we have developed. In the concluding part of the paper, we provide some of the results ob- tained in the experiments [less ▲]

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See detailJudgment Aggregation for Cooperative Anchoring on the NAO Robots
Ganesan, V.; Slavkovik, Marija UL; Sousa, S. et al

in Works-in-progress track - 3rd International Conference on Social Robotics (2011)

Cooperative anchoring is the sharing of associations between symbols and sensor data across multi robot systems. We apply the solution of Judgment Aggregation, a logic based collective-decision making ... [more ▼]

Cooperative anchoring is the sharing of associations between symbols and sensor data across multi robot systems. We apply the solution of Judgment Aggregation, a logic based collective-decision making framework from social choice theory to the problem of cooperative anchoring in terms of information fusion. We model a multi-agent system comprising of nao robots on a search exercise using its vision and audition sensor into this framework and fuse them by means of aggregation rules and compare them on a truth-tracking basis. [less ▲]

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See detailArguing about the Trustworthiness of the Information Sources
Villata, Serena; Boella, Guido; Gabbay, Dov M. UL et al

in ECSQARU (2011)

Trust minimizes the uncertainty in the interactions among the information sources. To express the possibly conflicting motivations about trust and distrust, we reason about trust using argumentation ... [more ▼]

Trust minimizes the uncertainty in the interactions among the information sources. To express the possibly conflicting motivations about trust and distrust, we reason about trust using argumentation theory. First, we show how to model the sources and how to attack untrustworthy sources. Second, we provide a focused representation of trust about the sources in which trust concerns not only the sources but also the information items and the relation with other information. [less ▲]

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See detailArgumentative Agents Negotiating on Potential Attacks
Boella, Guido; Gabbay, Dov M. UL; Perotti, Alan et al

in KES-AMSTA (2011)

When arguing, agents may want to discuss about the details after agreeing about the general problems. We propose to model this kind of situation using an extended argumentation framework with potential ... [more ▼]

When arguing, agents may want to discuss about the details after agreeing about the general problems. We propose to model this kind of situation using an extended argumentation framework with potential attacks. Agents negotiation about raising potential attacks or not, in order to maximize the number of their accepted arguments. The result of the negotiation process consists in the formation of coalitions composed by those agents which have found an agreement. The two proposed negotiation protocols have been implemented and an evaluation, addressed by means of experimental results, shows which combination of strategies and negotiation protocol allows the agents to optimize outcomes. [less ▲]

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See detailTowards Temporal Conviviality Measures
Caire, Patrice UL; Alcalde, Baptiste UL; van der Torre, Leon UL et al

in Benelux Conference on Artificial Intelligence (2011)

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See detailConviviality Measures
Caire, Patrice UL; Alcalde, Baptiste UL; van der Torre, Leon UL et al

in Proc. of 10th Int. Conf. on Autonomous Agents and Multiagent Systems (AAMAS 2011) (2011)

Conviviality has been introduced as a social science concept for multiagent systems to highlight soft qualitative requirements like user friendliness of systems. In this paper we introduce formal ... [more ▼]

Conviviality has been introduced as a social science concept for multiagent systems to highlight soft qualitative requirements like user friendliness of systems. In this paper we introduce formal conviviality measures for dependence networks using a coalitional game theoretic framework, which we contrast with more traditional efficiency and stability measures. Roughly, more opportunities to work with other people increases the conviviality, whereas larger coalitions may decrease the efficiency or stability of these involved coalitions. We first introduce assumptions and requirements, then we introduce a classification, and finally we introduce the conviviality measures. We use a running example from robotics to illustrate the measures. [less ▲]

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See detailArguing about Trust in Multiagent Systems
Villata, Serena; Boella, Guido UL; Gabbay, Dov M. UL et al

in Proceedings of the 11th Symposium on Artificial Intelligence of the Italian Association for Artificial Intelligence (AIIA'10) (2010)

Trust in multiagent systems is used for seeking to minimize the uncertainty in the interactions among the agents. In this paper, we discuss how to use argumentation to reason about trust. Using the ... [more ▼]

Trust in multiagent systems is used for seeking to minimize the uncertainty in the interactions among the agents. In this paper, we discuss how to use argumentation to reason about trust. Using the methodology of meta-argumentation, first we represent the source of the information from which the argument is constructed in the abstract argumentation framework capturing the fact that b is attacked because b is from a particular source s. We show how a source of information can be attacked if it is not evaluated as trustworthy. Second, we provide a fine grained representation of the trust relationships between the information sources in which trust concerns not only the sources but also the single arguments and attack relations the sources propose. Moreover, we represent the evidences in support of the arguments which are put forward by the information sources and the agents can express arguments by referring to other agents’ arguments. Meta-argumentation allows us not to extend Dung’s abstract argumentation framework by introducing trust and to reuse those principles and properties defined for Dung’s framework. [less ▲]

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See detailHigher-Order Coalition Logic
Boella, Guido UL; Gabbay, Dov M. UL; Genovese, Valerio UL et al

in Bibliothèque(s) : revue de l'Association des bibliothécaires de France (2010)

We introduce and study higher-order coalition logic, a multi modal monadic second-order logic with operators [{x}ψ]φ expressing that the coalition of all agents satisfying ψ(x) can achieve a state in ... [more ▼]

We introduce and study higher-order coalition logic, a multi modal monadic second-order logic with operators [{x}ψ]φ expressing that the coalition of all agents satisfying ψ(x) can achieve a state in which φ holds. We use neighborhood semantics to model extensive games of perfect information with simultaneous actions and we provide a framework reasoning about agents in the same way as it is reasoning about their abilities. We illustrate higher-order coalition logic to represent and reason about coalition formation and cooperation, we show a more general and expressive way to quantify over coalitions than quantified coalition logic, we give an axiomatization and prove completeness. [less ▲]

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See detailModal Access Control Logic - Axiomatization, Semantics and FOl Theorem Proving
Genovese, Valerio UL; Rispoli, Daniele; Gabbay, Dov M. UL et al

in STAIRS 2010 (2010)

We present and study a Modal Access Control Logic (M-ACL) to specify and reason about access control policies. We identify canonical properties of well-known access control axioms. We provide a Hilbert ... [more ▼]

We present and study a Modal Access Control Logic (M-ACL) to specify and reason about access control policies. We identify canonical properties of well-known access control axioms. We provide a Hilbert-style proof-system and we prove soundness, completeness and decidability of the logic. We present a sound and complete embedding of Modal Access Control Logic into First-Order Logic. We show how to use SPASS theorem prover to reason about access control policies expressed as formulas of Modal Access Control Logic, and we compare our logic with existing ones. [less ▲]

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See detailSupport in Abstract Argumentation
Boella, Guido UL; Gabbay, Dov M. UL; van der Torre, Leon UL et al

in Proceedings of the Third International Conference on Computational Models of Argument (COMMA'10) (2010)

n this paper, we consider two drawbacks of Cayrol and Lagasque-Schiex's meta-argumentation theory to model bipolar argumentation frameworks. We consider first the “lost of admissibility” in Dung's sense ... [more ▼]

n this paper, we consider two drawbacks of Cayrol and Lagasque-Schiex's meta-argumentation theory to model bipolar argumentation frameworks. We consider first the “lost of admissibility” in Dung's sense and second, the definition of notions of attack in the context of a support relation. We show how to prevent these drawbacks by introducing support meta-arguments. Like the model of Cayrol and Lagasque-Schiex, our formalization confirms the use of meta-argumentation to reuse Dung's properties. We do not take a stance towards the usefulness of a support relation among arguments, though we show that if one would like to introduce them, it can be done without extending Dung's theory. Finally, we show how to use meta-argumentation to instantiate an argumentation framework to represent defeasible support. In this model of support, the support relation itself can be attacked. [less ▲]

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See detailPrivacy Policies with Modal Logic: The Dynamic Turn
Aucher, Guillaume UL; Boella, Guido; van der Torre, Leon UL

in DEON (2010)

Privacy policies are often defined in terms of permitted messages. Instead, in this paper we derive dynamically the permitted messages from static privacy policies defined in terms of permitted and ... [more ▼]

Privacy policies are often defined in terms of permitted messages. Instead, in this paper we derive dynamically the permitted messages from static privacy policies defined in terms of permitted and obligatory knowledge. With this new approach, we do not have to specify the permissions and prohibitions of all message combinations explicitly. To specify and reason about such privacy policies, we extend a multi-modal logic introduced by Cuppens and Demolombe with update operators modeling the dynamics of both knowledge and privacy policies. We show also how to determine the obligatory messages, how to express epistemic norms, and how to check whether a situation is compliant with respect to a privacy policy.We axiomatize and prove the decidability of our logic. [less ▲]

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See detailA Logical Understanding of Legal Interpretation
Boella, Guido UL; Governatori, Guido; Rotolo, Antonino et al

in KR 2010 (2010)

If compliance with a norm does not achieve its purpose, then its applicability must dynamically be restricted or expanded. Legal interpretation is a mechanism from law allowing norms to be adapted to ... [more ▼]

If compliance with a norm does not achieve its purpose, then its applicability must dynamically be restricted or expanded. Legal interpretation is a mechanism from law allowing norms to be adapted to unforeseen situations. We model this mechanism for norms regulating computer systems by representing the purpose of norms by social goals and by revising the constitutive rules defining the applicability of norms. We illustrate the interpretation mechanism by examples. [less ▲]

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See detailGroup Intentions are Social Choice with Commitment
Boella, Guido UL; Pigozzi, Gabriella UL; Slavkovik, Marija UL et al

in Pre-Procs. of the 11th International Workshop on Coordination, Optimization, Institution and Norms in Multiagent Systems (COIN@MALLOW'10) (2010)

An agent intends g if it has chosen to pursue goal g an is committed to pursuing g . How do groups decide on a common goal? Social epistemology offers two views on collective attitudes: according to the ... [more ▼]

An agent intends g if it has chosen to pursue goal g an is committed to pursuing g . How do groups decide on a common goal? Social epistemology offers two views on collective attitudes: according to the summative approach, a group has attitude p if all or most of the group members have the attitude p; according to the non-summative approach, for a group to have attitude p it is required that the members together agree that they have attitude p. The summative approach is used extensively in multi-agent systems. We propose a formalization of non-summative group intentions, using social choice to determine the group goals. We use judgment aggregation as a decision-making mechanism and a multi-modal multi-agent logic to represent the collective attitudes, as well as the commitment and revision strategies for the groups intentions. [less ▲]

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See detailDeontic Redundancy: A Fundamental Challenge for Deontic Logic
van der Torre, Leon UL

in DEON (2010)

To decide which norms can be removed from a system, we need to know when a norm is redundant. After shifting the focus of attention in deontic logic from detachment of obligations and permissions to ... [more ▼]

To decide which norms can be removed from a system, we need to know when a norm is redundant. After shifting the focus of attention in deontic logic from detachment of obligations and permissions to deontic redundancy, I discuss in this paper five benchmark examples of deontic redundancy in reasoning about permissions, intermediate concepts and constitutive norms, deontic dilemmas, temporal deontic reasoning and contrary-to-duty reasoning. Then I discuss those benchmark examples in four formal approaches to deontic reasoning: traditional model logic, dynamic approaches, violation oriented or diagnostic systems, and imperativist or norm based approaches. [less ▲]

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See detailTrust in Abstract Argumentation
Boella, Guido UL; van der Torre, Leon UL; Villata, Serena

in Proceedings of the 4th Mahasarakham International Workshop on Artificial Intelligence (MIWAI'10) (2010)

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