Search

In the design of interactive media, various forms of intuitive practice come into play. It might prove tempting to use templates and strong narrative structures instead of developing the narrative directly for interactive media. This leads towards computer implementation too swiftly. The narrative bridging method focuses on the initial design phase, in which the conceptual modeling takes place. The purpose is to provide designers with a non-intrusive method that supports the design process without interfering with its creative elements. The method supports the sentient construction of digital games with a narrative, with the ultimate goal of enhancing the player΄s experience. A prototype test served as a first evaluation, and two games from that test are showcased here for the purpose of illustrating the hands-on use of narrative bridging. The test demonstrated that the method could aid time-constrained design, and in the process detect inconsistencies that could prevent the design team from making improvements. The method also provided teams with a shared vocabulary and outlook. [ABSTRACT FROM AUTHOR]

The beliefs of the agents in a multi-agent system have been formally modelled in the last decades using doxastic logics. The possible worlds model and its associated Kripke semantics provide an intuitive semantics for these logics, but they commit us to model agents that are logically omniscient. We propose a way of avoiding this problem, using a new kind of entities called subjective situations. We define a new doxastic logic based on these entities and we show how the belief operators have some desirable properties, while avoiding logical omniscience. A comparison with two well-known proposals (Levesque's logic of explicit and implicit beliefs and Thijsse's hybrid sieve systems) is also provided. [ABSTRACT FROM AUTHOR]

The aim of this paper is to analyse and formalise the dynamics of trust in the light of experiences. A formal framework is introduced for the analysis and specification of models for trust evolution and trust update. Different properties of these models are formally defined. [ABSTRACT FROM AUTHOR]

In this paper, we try to identify the relationships among three main (in our view) proposals of the basic mental attitudes in collaborative problem solving (the Toumela's theory of acting together, in particular the notion of We-Intention; the Grosz and Kraus' theory of collaboration, with special attention to the notion of Intention-that, and the Castelfranchi and Falcone' theory of Delegation-Adoption). We show several overlaps, convergencies, but also complementarities, contradictions and competitions among these theories. The aim of this paper is some clarification and systematisation of the necessary mental attitudes in agents' mind that characterise acting together and cooperating. We will not consider in this analysis other very important mental ingredients of complex forms of collaboration, like agents' motivations in taking part in collective activity, trust, and normative components: permissions, rights, norms, roles, etc. [ABSTRACT FROM AUTHOR]

We present a utility-driven rationality and a complementary-driven rationality based model, relative to multiple partner coalitions, motivated by relations of dependence and instrumental goal adoption. For this purpose, we analyze social dependency patterns and its corresponding dependency networks. The networks are used as a source of quantitative and qualitative information with which an agent is able to choose the best set of partners and adequate proposals to form coalitions. An e-commerce example is presented, showing the usefulness of the mechanism in real world multi-agent systems. [ABSTRACT FROM AUTHOR]

Cooperation plays a fundamental role in multi-agent systems in which individual agents must interact for the overall system to function effectively. However, cooperation inherently involves an element of risk, due to the unpredictable nature of other's behaviour. In this paper, we consider the information needed by an agent to be able to assess the degree of risk involved in a particular course of action. In particular, we consider how this information can be used in the process of plan selection in BDI-like agents. [ABSTRACT FROM AUTHOR]

The international telecommunications system is the largest distributed computing system in the world, composed of many autonomous subsystems with different ownership over resources and activities. To provide services to customers, these subsystems have to agree on joint activities and on the use of resources. But reaching such agreements is often hampered by unexpected and undesired interactions among the service features preferred by the various parties. These delay the introduction of new features to the market, complicate development and maintenance and cause dissatisfaction among users. In this paper we show how simple and clear models of interaction and behavior can be combined in a generic negotiation architecture able to automate the agreement reaching process between parties that have different preferences and different authority over resources and activities. The architecture integrates a conversational component, enforcing and ensuring the well-formedness of the interaction, a representation of action formalizing agents' authority to set obligations and interdictions upon other agents and a constraint optimization reasoning component allowing parties to deliberate over behaviors and outcomes to decide on their next move. [ABSTRACT FROM AUTHOR]

Argumentation is important for agent negotiation. In this paper, we develop an efficient framework for multi-agent argumentation. We identify aspects of classical argumentation theory that are suitable and useful for artificial agents and develop an argumentation framework around them. In the framework, we distinguish cooperation and argumentation and introduce skeptical and credulous agents. We develop an operational, goal-driven top-down proof procedure for the argumentation process and evaluate an implementation of our framework for an example of a BT business process. [ABSTRACT FROM AUTHOR]

Object-oriented languages generally support agent developments despite logic languages are more appropriate for managing mental attitudes. The alternative of a multi-paradigm language is a way for supporting agent constructions we explore. A multi-paradigm language that supports the encapsulation of actions, the hiding of private knowledge and the flexible manipulation of knowledge could be a good candidate for programming agents. Therefore, we present an approach for integrating object and logic paradigms based on logic modules combined with object-oriented abstractions. This approach aims at the construction of flexible agents in terms of easy extensions of the components of the logic interpreter. JavaLog, a particular implementation based on Java and Prolog, is also introduced. [ABSTRACT FROM AUTHOR]

A temporal dimension must be present in interactions between agents that must cooperate in continuously changing environments. In this paper, we present the definition of a temporal agent communication language. This language uses a sophisticated communication model based on the speech act theory. It is the component of a more important research dealing with the study of temporal reasoning in multi-agent systems. This work takes place, also, in the building of an interaction toolbox with temporal abilities in the context of a Multi-Agent System Platform in construction in our laboratory. [ABSTRACT FROM AUTHOR]

To provide inter-operability between heterogeneous agents in open systems, a commonly understood agent communication language (ACL) is used. To ensure that it is commonly understood, a formal semantics for the ACL is required. In this paper, we explore ideas from the semantics of natual language dialogues for defining the meaning of ACL messages. Using a general semantic framework for characterising the semantics of a class of ACLs in terms of protocols, we introduce a method for designing an ACL for a particular application. We illustrate this idea with respect to a small ACL called sACL. The advantages of this approach are that the specification is considerably less complex and more general, the potential for interoperability is improved, and verification of compliance to the semantics is easier. [ABSTRACT FROM AUTHOR]

This paper focuses on the study of the pragmatics of multi-agent systems design, proposing an efficient approach for the interaction protocol engineering. This approach combines two complementary paradigms: 1) Distributed observation is used to capture the concurrent events inherent to the interactions between agents, through causal dependency, in order to explain the relationships within conversations or group utterances; 2) Colored Petri Nets are used as a suitable formalism to identify interaction-oriented designs while providing the means to model, analyze, and validate large scale applications. [ABSTRACT FROM AUTHOR]

The Internet is rapidly becoming the privileged environment for today's Multi-Agent Systems. This introduces new issues in MAS' design and development, from both a conceptual and a technological viewpoint. In particular, the dichotomy between the openness of the execution environment and the need for secure execution models makes governing agents' interaction a really complex matter, especially when mobile agents are involved. If coordination is managing the interaction, then the issue of agent coordination is strictly related with the issues of topology (how the space where agents live and possibly move is modelled and represented), authentication (how agents are identified), and authorisation (what agents are allowed to do). To this end, we first discuss the TuCSoN model for the coordination of Internet agents, then show how it can be extended to model the space where agents live and interact as a hierarchical collection of locality domains, where programmable coordination media are exploited to rule agent interaction and to support intelligent agent exploration. This makes TuCSoN result in a single coherent framework for the design and development of Internet-based MAS, which takes coordination as the basis for dealing with network topology, authentication and authorisation in a uniform way. [ABSTRACT FROM AUTHOR]

Over the last few years more complex techniques have been used to develop hard real-time systems, and the multi-agent system paradigm seems to be an appropriate approach to be applied in this area. The temporal restrictions of these systems made necessary to build agents architectures that satisfy these restrictions. A formal Agent architecture to model hard-real time systems is proposed in this paper. A prototype that follows this agent architecture and works in a hard real-time environment has been implemented. Finally, a study case is described to show the design agent process. [ABSTRACT FROM AUTHOR]

This paper presents a development environment suitable for the design and implementation of multi-agent systems. This environment is designed following the guidelines found in FIPA specifications. Therefore, it offers the management agents and services necessary to realize a FIPA-compliant open system. An agent prototype is also provided in order to ease the implementation of domain-specific agents. Even if the development environment mainly supports the C++ language, the resulting architectures are heavily based on the concept of roaming agent through a distributed environment. Interoperability with other systems, supporting other languages such as Java, is guaranteed by FIPA specifications. The presented environment has been used to develop a multi-agent system that should integrate the different software modules performing sensory data interpretation, planning and faults diagnosis of a robot working in a space station. [ABSTRACT FROM AUTHOR]

This paper draws upon the practical experience gained in the development of software agents for the deployment of intelligent distributed services and information access. We review a set of multi-agent architectures starting from the communication and co-ordination requirements of such systems. The aim is to illustrate the common components in current designs and implementations of MAS which are often based on the communication nature of these systems. Further to this we show some benefits and drawbacks of these systems that are developed form this aspect. Part of the limitations of these systems is due to basing their communication semantic interpretation on the belief desire and intention model (BDI) which is a mental agency. The mental agency is used for the internal reasoning part of the agent and places implicit assumptions on the communication behaviour. We examine this limitation and report on how two MASs overcome some of the constraints. In light of these practical solutions we outline some pragmatic design concepts in reducing potential constraints of the BDI model on the communication layer. The result is a discussion about how to bridge between mental agency dependencies and the role of social agency when developing multi-agent systems. [ABSTRACT FROM AUTHOR]

Recent development in the field of Multi-Agent Systems (MAS) has attracted researchers from various fields with new techniques rapidly emerging. Due to its multi-disciplinary nature, it is not surprising that proposed theories and research results in the field are not coherent and hard to integrate. In this paper we propose a functional decomposition of problem solving activities to serve as a framework to assist MAS designers in their selection and integration of different techniques and existing research results according to their system requirements. The basic phases include agent organization construction, plan generation, task allocation, plan integration, and plan execution. An example usage of the proposed model for the domain of naval radar frequency management is also presented. [ABSTRACT FROM AUTHOR]

In this paper it is shown how informal and formal specification of behavioural requirements and scenarios for agents and multi-agent systems can be integrated within multi-agent system design. In particular, it is addressed how a compositional perspective both on design descriptions and specification of behavioural requirements can be exploited. The approach has been applied in a case study: the development of a mediating information agent. It is shown that compositional verification benefits from the integration of requirements engineering within the design process. [ABSTRACT FROM AUTHOR]

Increasingly many computer systems are being viewed in terms of autonomous agents. Agents are being espoused as a new theoretical model of computation that more closely reflects current computing reality than Turing Machines. Agents are being advocated as the next generation model for engineering complex, distributed systems. Agents are also being used as an overarching framework for bringing together the component AI sub-disciplines that are necessary to design and build intelligent entities. Despite this intense interest, however, a number of fundamental questions about the nature and the use of agents remain unanswered. In particular: what is the essence of agent-based computing?what makes agents an appealing and powerful conceptual model?what are the drawbacks of adopting an agent-oriented approach?what are the wider implications for AI of agent-based computing? [ABSTRACT FROM AUTHOR]