Kostas Stathis

Situating Cognitive Agents in GOLEM

We investigate the application of a logic-based framework representing an agent environment as a composite structure that evolves over time. Such a complex structure contains the interaction between two main classes of entities: agentsand objects. Interactions between these entities are specified in term of eventswhose occurrence is governed by a set of physical lawsspecifying the possible evolutions of the agent environment, including how these evolutions are perceived by agents and affect objects and processes in the agent environment. We illustrate the work using GOLEM, a protype platform whose aim is to implement the framework to build situated cognitive agents in a distributed agent environment.

Normative KGP agents

We extend the logical model of agency known as the KGP model, to support agents with normative concepts, based on the roles an agent plays and the obligations and prohibitions that result from playing these roles. The proposed framework illustrates how the resulting normative concepts, including the roles, can evolve dynamically during the lifetime of the agent. Furthermore, we illustrate how these concepts can be combined with the existing capabilities of KGP agents in order to plan for their goals, react to changes in the environment, and interact with other agents. Our approach gives an executable specification of normative concepts that can be used directly for prototyping applications.

The KGP model of agency for global computing: computational model and prototype implementation

We present the computational counterpart of the KGP (Knowledge, Goals, Plan) declarative model of agency for Global Computing. In this context, a computational entity is seen as an agent developed using Computational Logic tools and techniques. We model a KGP agent by relying upon a collection of capabilities, which are then used to define a collection of transitions, to be used within logically specified, context sensitive control theories, which we call cycle theories. In close relationship to the declarative model, the computational model mirrors the logical architecture by specifying appropriate computational counterparts for the capabilities and using these to give the computational models of the transitions. These computational models and the one specified for the cycle theories are all based on, and are significant extensions of, existing proof procedures for abductive logic programming and logic programming with priorities. We also discuss a prototype implementation of the overall computational model for KGP.

Distributed agent environments in the Ambient Event Calculus

We study the development of distributed agent environments as distributed event-based systems specified in the Ambient Event Calculus (AEC). The AEC is a logic-based formalism that is developed here to support the representation of a distributed agent environment as a persistent composite structure evolving over time. Such a complex structure supports the interaction between agents, objects, and containers, entities that have their own external observable state and can be distributed over a network. Interactions between these entities are specified in terms of events that represent actions executed by agents on objects and other agents in the environment. When events happen they are stored in containers and are notified to agent sensors that subscribe to event descriptions and as a result perceive the interactions. The AEC formalism also allows changes caused by events to be delivered across distributed containers, according to the topology of the application environment. We illustrate the use of AEC and we show how to specify interactions within the GOLEM agent platform applied to a specific agent scenario.

COMMODITY12: A smart e-health environment for diabetes management

We present the development of COMMODITY12, a Personal Health System PHS to assist in the provision of continuous and personalised health services to diabetic patients, thus empowering their lifestyle regardless of their location. COMMODITY12 consists of ambient, wearable and portable devices, which acquire, monitor and communicate physiological parameters and other health-related context of an individual, such as physical activity and vital body signals. This data is interpreted by intelligent agents that use expert biomedical knowledge to derive important insights about the individuals health status, which are then presented in the form of active feedback to the patient directly from the device, or via health professionals who assist in diagnosis, treatment and life management. The emphasis of the work is on the design of the PHS in terms of its main components, their integration and deployment to address major problems of interest to both diabetic patients and doctors that treat diabetes.

Ambient Intelligence Using KGP Agents

We investigate the application of a logical model of agency, known as the KGP model, to develop agents for ambient intelligence applications. Using a concrete scenario, we illustrate how the logical formalism employed by a KGP agent allows a person to access the surrounding ambient through the agent in a transparent manner. We evaluate our claims by implementing the resulting interactions in PROSOCS, a prototype multi-agent systems platform that allows KGP agents to be deployed as components of ambient intelligence applications.

Living memory: agent-based information management for connected local communities

We investigate the application of multi-agent systems to develop intelligent information interfaces for connected communities, a class of computer applications aimed at enhancing the way people interact and socialise in geographically co-located communities such as neighbourhoods. In this context, we study the problem of providing effective information management in support of social interaction when a diverse range of computing devices is employed. The novelty of our approach is based on combining innovative interactive devices with a framework based on agent roles in order to support the effective flow of community-related content for the people of a given locality. In particular, we have integrated existing techniques for information retrieval and filtering with measures of content popularity, to ensure that documents in the community system are optimally available. After reporting on the potential presence of the system in the community, we report on the development of a framework for multi-agent systems in which agents provide a number of services aimed at facilitating personalised and location-dependent information access to members of the community. We also present a summary of the results of an expert evaluation of the information flow resulting from the communication between agents, and a user-evaluation of the information dissemination facilities provided by the system. q 2002 Elsevier Science B.V. All rights reserved.

Computational logic foundations of KGP agents

This paper presents the computational logic foundations of a model of agency called the KGP (Knowledge, Goals and Plan) model. This model allows the specification of heterogeneous agents that can interact with each other, and can exhibit both proactive and reactive behaviour allowing them to function in dynamic environments by adjusting their goals and plans when changes happen in such environments. KGP provides a highly modular agent architecture that integrates a collection of reasoning and physical capabilities, synthesised within transitions that update the agents state in response to reasoning, sensing and acting. Transitions are orchestrated by cycle theories that specify the order in which transitions are executed while taking into account the dynamic context and agent preferences, as well as selection operators for providing inputs to transitions.

Connected communities from the standpoint of multi-agent systems

We study the provision of software agents for connected communities, a class of applications aiming to augment the way people interact and socialize in geographically co-located communities such as neighbourhoods. Following a number of experiments that we have carried out in this area, we propose a multi-agent architecture and we study how to instantiate it in order to design a specific connected community system. We further report on the research challenges, the opportunities and risks raised by agent-based connected communities.

The ArguGRID Platform: An Overview

The ArguGRID project aims at supporting service selection and composition in distributed environments, including the Grid and Service-oriented architectures, by means of argumentative agents, an agent environment, a service-composition environment, Peer-to-Peer technology and Grid middleware. Agents are argumentative in that they use argumentation-based decision-making and argumentation-supported negotiation of services and contracts. The integration of all technologies gives rise to the overall ArguGRID platform. In this paper we outline the main components and the overall functionalities of the ARGUGRID platform.