244 research outputs found

    Artificial institutions: a model of institutional reality for open multiagent systems

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    Software agentsā€™ ability to interact within different open systems, designed by different groups, presupposes an agreement on an unambiguous definition of a set of concepts, used to describe the context of the interaction and the communication language the agents can use. Agentsā€™ interactions ought to allow for reliable expectations on the possible evolution of the system; however, in open systems interacting agents may not conform to predefined specifications. A possible solution is to define interaction environments including a normative component, with suitable rules to regulate the behaviour of agents. To tackle this problem, we propose an application-independent model of artificial institutions that can be used to define open multiagent systems. With respect to other approaches to artificial (or electronic) institutions, which mainly focus on the definition of the normative component of open systems, our proposal has a wider scope, in that we model the social context of the interaction, define the semantics of an Agent Communication Language to operate on such a context, and give an operational definition of the norms that are necessary to constrain the agentsā€™ actions. In particular, we define the semantics of a library of communicative acts in terms of operations on agentsā€™ social reality, more specifically on commitments, and regard norms as event-driven rules that, when fired by events happening in the system, create or modify a set of commitments. An interesting aspect of our proposal is that both the definition of the ACL and the definition of norms are based on the same notion of commitment. Therefore an agent capable of reasoning on commitments can reason both on the semantics of communicative acts and on the normative system

    Artificial institutions: a model of institutional reality for open multiagent systems

    Get PDF
    Software agents' ability to interact within different open systems, designed by different groups, presupposes an agreement on an unambiguous definition of a set of concepts, used to describe the context of the interaction and the communication language the agents can use. Agents' interactions ought to allow for reliable expectations on the possible evolution of the system; however, in open systems interacting agents may not conform to predefined specifications. A possible solution is to define interaction environments including a normative component, with suitable rules to regulate the behaviour of agents. To tackle this problem we propose an application-independent metamodel of artificial institutions that can be used to define open multiagent systems. In our view an artificial institution is made up by an ontology that models the social context of the interaction, a set of authorizations to act on the institutional context, a set of linguistic conventions for the performance of institutional actions and a system of norms that are necessary to constrain the agents' action

    Aligning Models of Normative Systems and Artificial Societies: Towards norm-governed behavior in virtual enterprises

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    The purpose is to explore how norm-governed behavior within agent societies can be achieved in the context of Virtual Enterprises. We analyze a number of formal models from the agent research field, of which three models focus on the society aspects and three models focus on norms. A general observation is that the models reviewed are not concordant with each other and therefore require further alignment. A number of additions that may enrich the norm-focused models are suggested. It is also concluded that the introduction of different types of norms on different levels can be applied to ensure sound collaboration in agent-supported virtual enterprises. Moreover, the deployment of norm defender and promoter functionality is suggested to ensure norm compliance and punishments of norm violations

    Agent communication and artificial institutions

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    In this paper we propose an application-independent model for the definition of artificial institutions that can be used to define open multi-agent systems. Such a model of institutional reality makes us able also to define an objective and external semantics of a commitment-based Agent Communication Language (ACL). In particular we propose to regard an ACL as a set of conventions to act on a fragment of institutional reality, defined in the context of an artificial institution. Another contribution of the work presented in this paper is an operational definition of norms, a crucial component of artificial institutions. In fact in open systems interacting agents might not conform to the specifications. We regard norms as event-driven rules that when are fired by events happening in the system create or cancel a set of commitments. An interesting aspect of our proposal is that both the definition of the ACL and the definition of norms are based on the same notion of commitment. Therefore an agent capable of reasoning on commitments can reason on the semantics of communicative acts and on the system of norm

    An operational approach to norms in artificial institutions

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    The notion of artificial institution is crucial for the specification of open and dynamic interaction frameworks where heterogeneous and autonomous agents can interact to face problems in various fields, like for instance electronic commerce, business-to-business (B2B) applications, and personal assistant applications. In our view the specification of artificial institutions requires a clear standard definition of some basic concepts: the notion of ontology, authorizations, conventions, and norms. In this paper we propose an operational approach to the definition of norms that is mainly based on the generation of commitments. These norms can be employed to verify if the interacting agents are behaving in accordance with the normative specification of the system. In particular we regard norms as event-driven rules that are fired by events happening in the system and then modify commitments affecting the agents having a certain role. We will discuss the crucial differences between the notion of authorization and permission and how the notion of permissions, obligations, and prohibitions can be expressed in our model. We will investigate the connections among the specification of different artificial institutions, in particular how an institution can enrich or further regulate the entities defined in another one. Finally we will briefly present the specification of the Dutch Auction Institution and of the Auction House Institution in order to exemplify the model presented in this paper

    Desen: Specification of Sociotechnical Systems via Patterns of Regulation and Control

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    We address the problem of engineering a sociotechnical system (STS) with respect to its stakeholdersā€™ requirements. We motivate a two-tier STS conception comprising a technical tier that provides control mechanisms and describes what actions are allowed by the software components, and a social tier that characterizes the stakeholdersā€™ expectations of each other in terms of norms. We adopt agents as computational entities, each representing a different stakeholder. Unlike previous approaches, our framework, Desen, incorporates the social dimension into the formal verification process. Thus, Desen supports agents potentially violating applicable normsā€”a consequence of their autonomy. In addition to requirements verification, Desen supports refinement of STS specifications via design patterns to meet stated requirements. We evaluate Desen at three levels. We illustrate how Desen carries out refinement via the application of patterns on a hospital emergency scenario. We show via a human-subject study that a design process based on our patterns is helpful for participants who are inexperienced in conceptual modeling and norms. We provide an agent-based environment to simulate the hospital emergency scenario to compare STS specifications (including participant solutions from the human-subject study) with metrics indicating social welfare and norm compliance, and other domain dependent metrics

    Kont: Computing tradeoffs in normative multiagent systems

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    We propose Kont, a formal framework for comparing normative multiagent systems (nMASs) by computing tradeoffs among liveness (something good happens) and safety (nothing bad happens). Safety-focused nMASs restrict agents' actions to avoid undesired enactments. However, such restrictions hinder liveness, particularly in situations such as medical emergencies. We formalize tradeoffs using norms, and develop an approach for understanding to what extent an nMAS promotes liveness or safety. We propose patterns to guide the design of an nMAS with respect to liveness and safety, and prove their correctness. We further quantify liveness and safety using heuristic metrics for an emergency healthcare application. We show that the results of the application corroborate our theoretical development

    A Normative Multiagent Approach to Requirements Engineering

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    Abstract. In this paper we present a new model for the requirements analysis of a system. We offer a conceptual model defined following a visual modeling language, called dependence networks. TROPO
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