Open Agent Societies Research Articles

The open agent society: retrospective and prospective views

It is now more than ten years since the EU FET project ALFEBIITE finished, during which its researchers made original and distinctive contributions to (inter alia) formal models of trust, model-checking, and action logics. ALFEBIITE was also a highly inter-disciplinary project, with partners from computer science, philosophy, cognitive science and law. In this paper, we reflect on the interaction between computer scientists and information and IT lawyers on the idea of the `open agent society'. This inspired a programme of research whose investigation into conceptual challenges has carried it from the logical specification of agent societies and dynamic norm-governed systems to self-organising electronic institutions, while developing several technologies for agent-based modelling and complex event recognition. The outcomes of this inter-disciplinary collaboration have also influenced current research into using the open agent society as a platform for socio-technical systems, and other collective adaptive systems. We present a number of research challenges, including the ideas of computational justice and polycentric governance, and explore a number of ethical, legal and social implications. We contend that, in order to address these issues and challenges, the continued inter-disciplinary collaboration between computer science and IT lawyers is critical.

Dynamics of Artificial Agent Societies: A survey and an agent migration perspective

Artificial Agent Societies are analogous to human societies in which a collection of agents (analogous to humans) are residing or inhabiting a specific locality and are interacting with each other, for some solving common/individual purpose. Social networks, electronic markets and disaster management organizations can be viewed as such artificial (open) agent societies and hence can be best understood as computational societies. The members of such artificial agent societies are heterogeneous intelligent software agents, which are operating locally, cooperating and coordinating with each other in order to achieve goals of an agent society. These open agent societies have some kind of dynamics existing in them, in terms of dynamics of Agent Migration, Role-Assignment, Norm-Emergence, Security and Agent-Interaction. All these dynamic aspects are very closely interrelated to each other, as change in one reflects changes in others also. In this paper, we have presented a survey of all these dynamic aspects of an open agent society at its design-time and have tried to relate them to its member as well as non-member (external) agents. We have also related them, to the migration of a new agent in an open agent society, i.e., how role-assignment will be done for it, various issues related to security and trust of a society upon its arrival, issues related to norm-identification and norm-emergence for it and its communication with the rest of the member agents of the society, that also, during and after its migration. In addition to this, we have also outlined various research challenges and directions available in the area of dynamics of artificial agent societies.

Self-organization in service discovery in presence of noncooperative agents

Self-organization and cooperation of agents in open societies play an important role in the success of the service discovery process. Self-organization allows agents to deal with dynamic requirements in service demand. Moreover, in distributed environments where service discovery is carried out by agents that only have a partial view of the system, cooperation with neighbors is a key issue in order to locate the required services. However, cooperation is not always present in open agent societies. With this motivation, we present a set of mechanisms that consider self-organization actions and incentives to adapt the structure of the society to the service demand and to promote a cooperative behavior among agents in open societies.

STRATEGIES FOR COOPERATION EMERGENCE IN DISTRIBUTED SERVICE DISCOVERY

In distributed environments where entities only have a partial view of the system, cooperation is a key issue. In the case of decentralized service discovery in open agent societies, agents only know about the services they provide and who their direct neighbors are. Therefore, they need the cooperation of their neighbors in order to locate the required services. However, cooperation is not always present in open systems. Noncooperative agents pursuing their own goals could refuse to forward queries from other agents to avoid the cost of this action; therefore, the efficiency of the decentralized service discovery could be seriously damaged. In this article, we propose the combination of incentives and local structural changes in order to promote cooperation in the service discovery process. The results show that, even in scenarios where the predominant behavior is not collaborative, cooperation emerges.

Migration Dynamics in Artificial Agent Societies

An Artificial Agent Society can be defined as a collection of agents interacting with each other for some purpose and/or inhabiting a specific locality, possibly in accordance to some common norms/rules. These societies are analogous to human and ecological societies, and are an expanding and emerging field in research about social systems. Social networks, electronic markets and disaster management organizations can be viewed as such artificial (open) agent societies and can be best understood as computational societies. Members of such artificial agent societies are heterogeneous intelligent software agents which are operating locally and cooperating and coordinating with each other in order to achieve goals of an agent society. These artificial agent societies have some kind of dynamics existing in them in terms of dynamics of Agent Migration, Role-Assignment, Norm- Emergence, Security and Agent-Interaction. In this paper, we have described the dynamics of agent migration process, starting from the various types of agent migration, causes or reasons for agent migration, consequences of agent migration, and an agent migration framework to model the its behavior for migration of agents between societies.

Identifying prohibition norms in agent societies

In normative multi-agent systems, the question of "how an agent identifies norms in an open agent society" has not received much attention. This paper aims at addressing this question. To this end, this paper proposes an architecture for norm identification for an agent. The architecture is based on observation of interactions between agents. This architecture enables an autonomous agent to identify prohibition norms in a society using the prohibition norm identification (PNI) algorithm. The PNI algorithm uses association rule mining, a data mining approach to identify sequences of events as candidate norms. When a norm changes, an agent using our architecture will be able to modify the norm and also remove a norm if it does not hold in the society. Using simulations of a park scenario we demonstrate how an agent makes use of the norm identification framework to identify prohibition norms.

Recognizing and learning models of social exchange strategies for the regulation of social interactions in open agent societies

Abstract Regulation of social exchanges refers to controlling social exchanges between agents so that the balance of exchange values involved in the exchanges are continuously kept—as far as possible—near to equilibrium. Previous work modeled the social exchange regulation problem as a POMDP (Partially Observable Markov Decision Process), and defined the policyToBDIplans algorithm to extract BDI (Beliefs, Desires, Intentions) plans from POMDP models, so that the derived BDI plans can be applied to keep in equilibrium social exchanges performed by BDI agents. The aim of the present paper is to extend that BDI-POMDP agent model for self-regulation of social exchanges with a module, based on HMM (Hidden Markov Model), for recognizing and learning partner agents’ social exchange strategies, thus extending its applicability to open societies, where new partner agents can freely appear at any time. For the recognition problem, patterns of refusals of exchange proposals are analyzed, as such refusals are produced by the partner agents. For the learning problem, HMMs are used to capture probabilistic state transition and observation functions that model the social exchange strategy of the partner agent, in order to translate them into POMDP’s action-based state transition and observation functions. The paper formally addresses the problem of translating HMMs into POMDP models and vice versa, introducing the translation algorithms and some examples. A discussion on the results of simulations of strategy-based social exchanges is presented, together with an analysis about related work on social exchanges in multiagent systems.

Specifying norm-governed computational societies

Electronic markets, dispute resolution and negotiation protocols are three types of application domains that can be viewed as open agent societies. Key characteristics of such societies are agent heterogeneity, conflicting individual goals and unpredictable behavior. Members of such societies may fail to, or even choose not to, conform to the norms governing their interactions. It has been argued that systems of this type should have a formal, declarative, verifiable, and meaningful semantics. We present a theoretical and computational framework being developed for the executable specification of open agent societies. We adopt an external perspective and view societies as instances of normative systems. In this article, we demonstrate how the framework can be applied to specifying and executing a contract-net protocol. The specification is formalized in two action languages, the C + language and the Event Calculus, and executed using respective software implementations, the Causal Calculator and the Society Visualizer. We evaluate our executable specification in the light of the presented case study, discussing the strengths and weaknesses of the employed action languages for the specification of open agent societies.

Verifiable agent interaction in abductive logic programming

SCIFF is a framework thought to specify and verify interaction in open agent societies. The SCIFF language is equipped with a semantics based on abductive logic programming; SCIFF's operational component is a new abductive logic programming proof procedure, also named SCIFF, for reasoning with expectations in dynamic environments. In this article we present the declarative and operational semantics of the SCIFF language, and the termination, soundness, and completeness results of the SCIFF proof procedure, and we demonstrate SCIFF's possible application in the multiagent domain.

Specification and Verification of Agent Interaction Protocols in a Logic-based System

A number of information systems can be described as a set of interacting entities, which must follow interaction protocols. These protocols determine the behaviour and the properties of the overall system, hence it is of the uttermost importance that the entities behave in a conformant manner. A typical case is that of multi-agent systems, composed of a plurality of agents without a centralized control. Compliance to protocols can be hardwired in agent programs; however, this requires that only certified agents interact. In open systems, composed of autonomous and heterogeneous entities whose internal structure is, in general, not accessible (open agent societies being, again, a prominent example) interaction protocols should be specified in terms of the observable behaviour, and compliance should be verified by an external entity. In this paper, we propose a Java-Prolog- system for verification of compliance of computational entities to protocols specified in a logic-based formalism ( Social Integrity Constraints ). We also show the application of the formalism and the system to the specification and verification of three different scenarios: two specifications show the feasibility of our approach in the context of Multi Agent Systems (FIPA Contract-Net Protocol and Semi-Open societies), while a third specification applies to the specification of a lower level protocol (Open-Connection phase of the TCP protocol).

The open agent society as a platform for the user-friendly information society

A thematic priority of the European Union’s Framework V research and development programme was the creation of a user-friendly information society which met the needs of citizens and enterprises. In practice, though, for example in the case of on-line digital music, the needs of citizens and enterprises may be in conflict. This paper proposes to leverage the appearance of ‘intelligence’ in the platform layer of a layered communications architecture to avoid such conflicts in similar applications in the future. The key idea is that if the intelligence is encapsulated in an agent, then the agents should be organized as a society, and then the rules of the society can be used to ensure ‘responsible’ behaviour. We discuss how an agent society can be used to regulate behaviour in future information trading scenarios, and conclude that this approach offers a ‘third way’ which can satisfy the (reasonable) needs of both citizens and enterprises in the user-friendly information society.

The open agent society and its enemies: a position statement and research programme

Virtual enterprises and connected communities are common visions of future commercial and social structures. Underpinning these visions is the idea of the open agent society: a flexible network of heterogeneous software processes, each individually aware of the opportunities available to them, capable of autonomous decision making to take advantage of them, and co-operating to meet transient needs and conditions. Furthermore, the society should be regulated by the kind of relations (contractual and normative) found in human business and social interactions. This paper reviews experience with developing, deploying and evaluating multi-agent systems, and distills from this some of the drivers for the open agent society. We then identify three crucial innovations which will help realise this idea. However, the development of the open agent society is exposed to certain risks, and we consider a number of `enemies' which threaten its development. We conclude that an awareness of the risks entails new paradigms for engineering multi-agent systems, in which dynamic social relationships are as important as interface definitions in providing the interoperability required for the open agent society.