A finer grained modeling of rational coalitions using goals

We propose an extension of Coalitional ATL (a logic for reasoning about coalitions and their formation process, see [10]) by goals. This goal framework allows for a finer grained modeling of coalitions: Coalitional frameworks, based on Dungs’s abstract argumentation framework, are used to point out conflicts between agents, and goals refer to agents’ subjective incentives to join (or not to join) coalitions. We focus on two different aspects for cooperation allowing a more practical modeling of systemsWorkshop de Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI

Formal methods for analysing, coordinating, and controlling decisions in multi-agent systems

Multiagentensysteme sind verteilte (Computer)Systeme, die sich aus autonomen interagierenden Systemkomponenten, bezeichnet als Agenten, zusammensetzen. Sie bieten ein flexibles Framework zur Modellierung und Analyse von interaktiven Systemen, in denen Kooperation, Eigeninteresse und Autonomie eine entscheidende Rolle spielen. Dies ist zum Beispiel der Fall in Smart Grids. Eine Herausforderung in solchen Systemen ist die Kontrolle und die Koordination von Systemausführungen. Agenten handeln autonom und lassen sich daher oftmals nicht direkt kontrollieren, sondern bestenfalls beeinflussen. Aufgrund der Autonomie und des Selbstinteresses, ist es schwierig, angemessene Kontrollmechanismen zu finden. Die vorliegende Arbeit behandelt formale Grundlagen zu den Themen Entscheidungsfindung, Koordination und Kontrolle in Multiagentensystemen. Insbesondere werden in diesem Zusammenhang Logiken zur Analyse und Spezifikation von strategischen Fähigkeiten von Agenten, unter diversen Restriktionen, untersucht. Es werden formale Ansätze zur Beeinflussung und Überwachung von Systemausführungen eingeführt. In einem weiteren Teil der Arbeit wird mittels spieltheoretischer Verfahren analysiert, wie rationale Agenten interagieren und Entscheidungen treffen. Es wird argumentiert, dass formale Methoden und Werkzeuge zur Analyse und Kontrolle von autonomen Systemen entscheidend für deren verlässliche Entwicklung sind.Multi-agent systems (MASs) are distributed (computer) systems composed of autonomously (inter-)acting system components referred to as agents. MASs offer a flexible framework to model and analyse many real world settings in which cooperation, self-interest, and autonomy are crucial elements. A key challenge in such settings is the control and coordination of behavior. However, due to the agents' autonomy behavior can often not be controlled, but at best be influenced in some way or another. For example, agents can be given incentives in order to affect their decision-making in such a way that the emergent behavior of all actors is desirable from the system's perspective. The properties of self-interest and autonomy make it challenging to find appropriate control mechanisms. Existing coordination and control approaches from the distributed system literature are often not applicable due to the lack of direct control on the system components of MASs. New methods and tools are needed. In this thesis formal foundations related to the subjects of decision making, coordination and control in MASs are studied. In particular, we investigate (extensions of) temporal and strategic logics which capture specific capabilities of agents that influence their decision making. We also propose formal approaches to control, coordinate and monitor the emergent behavior in MASs. In the last part of the thesis we analyse how rational agents interact and make decisions using game theoretical methods. We argue that such formal approaches and tools to analyse and control autonomous systems are crucial for the development of reliable and flexible systems and will become even more crucial in the near future

Practical run-time norm enforcement with bounded lookahead

Norms have been widely proposed as a means of coordinating and controlling the behaviour of agents in a multi-agent system. A key challenge in normative MAS is norm enforcement: how and when to restrict the agents’ behaviour in order to obtain a desirable outcome? Even if a norm can be enforced theoretically, it may not be enforceable in a grounded, practical setting. In this paper we study the problem of practical norm enforcement. The key notion is that of a guard. Guards are functions which restrict the possible actions after a history of events. We propose a formal, computational model of norms, guards and norm enforcement, based on linear-time temporal logic with past operators. We show that not all norms can be enforced by such guard functions, even in the presence of unlimited computational power to reason about future events. We analyse which norms can be enforced by guards if only a fixed lookahead is available. We investigate decision problems for this question with respect to specific classes of norms, related to safety and liveness properties

A finer grained modeling of rational coalitions using goals

We propose an extension of Coalitional ATL (a logic for reasoning about coalitions and their formation process, see [10]) by goals. This goal framework allows for a finer grained modeling of coalitions: Coalitional frameworks, based on Dungs’s abstract argumentation framework, are used to point out conflicts between agents, and goals refer to agents’ subjective incentives to join (or not to join) coalitions. We focus on two different aspects for cooperation allowing a more practical modeling of systemsWorkshop de Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI

Agents, beliefs, and plausible behavior in a temporal setting

In this paper, we add a notion of plausible behavior to the branching-time logic CTL so that we obtain a language to reason about what can (or must) plausibly happen. Moreover, we propose a non-standard notion of beliefs, which is defined in terms of epistemic relations and plausibility and we investigate properties of plausibility, knowledge and beliefs in this new framework. In particular, we show that knowledge is still an S5 modality, and that beliefs satisfy axioms K45 in general, and KD45 for the class of so called plausibly serial models. Finally, we show that the relationship between knowledge and beliefs for plausibly serial models is very natural and reflects the initial intuition well. Keywords: multi-agent systems, temporal logic, plausibility, beliefs

On the boundary of (un)decidability: decidable model-checking for a fragment of resource agent logic

The model-checking problem for Resource Agent Logic is known to be undecidable. We review existing (un)decidability results and identify a significant fragment of the logic for which model checking is decidable. We discuss aspects which makes model checking decidable and prove undecidability of two open fragments over a class of models in which agents always have a choice of doing nothing