The Strobe Model: Dynamic Service Generation on the Grid

Abstract

This article presents the STROBE model: both an agent representation and an agent communication model based on a social approach, that means interaction centred. This model represents how agents may realise the interactive, dynamic generation of services on the Grid. Dynamically generated services embody a new concept of service implying a collaborative creation of knowledge i.e. learning; services are constructed interactively between agents depending on a conversation. The approach consists of integrating selected features from Multi-Agent Systems and agent communication, language interpretation in applicative/functional programming and e-learning/human-learning into a unique, original and simple view that privileges interactions, yet including control. The main characteristic of STROBE agents is that they develop a language (environment + interpreter) for each of their interlocutors. The model is inscribed within a global approach, defending a shift from the classical algorithmic (control based) view to problem solving in computing to an interaction-based view of Social Informatics, where artificial as well as human agents operate by communicating as well as by computing. The paper shows how the model may not only account for the classical communicating agent approaches, but also represent a fundamental advance in modelling societies of agents in particular in Dynamic Service Generation scenarios such as those necessary today on the Web and proposed tomorrow for the Grid. Preliminary concrete experimentations illustrate the potential of the model; they are significant examples for a very wide class of computational and learning situations.

Service-Based Integration of Grid and Multi-Agent Systems Models

“…Notice that key GRID concepts presented in this section have been established according to the OGSA or WSRF specifications. Similarly, key MAS concepts have been established by different approaches in the MAS literature [22,28] but especially the STROBE model [8,9]. As we are focussing on concepts, we adopt the most convenient terminology from these sets of specifications.…”

“…Conversations and their states are represented in the STROBE model by cognitive environments. We can explore further the concept of cognitive environments, 8 which is a relatively new, but very important, concept related to the STROBE agent and communication model [8,9,29,30]. In the STROBE model agents are able to interpret communication messages in a given conversation context that includes an interpreter, dedicated to the current conversation.…”

“…An agent may have several cognitive environments In MAS, when an agent has a conversation, it dedicates a part of its state to this conversation. It is called the conversation context [8,22]. For example, during service exchanges, the service provider maintain a set of explicit interaction contexts, corresponding to each of its users.…”

“…The next generation of services will consist of dynamically generated services, i.e., services constructed on the fly by the service provider according to the conversation it has with the service user. In Dynamic Service Generation (DSG), term suggested by [8,9], the user (human or artificial) is not assumed to know exactly what the provider (also human or artificial) can offer him. He finds out and constructs step by step what he wants based on the service provider's reactions.…”

“…Singh and Huhns [7] talk about service engagement, instead of simple method invocation. In [8,9] we present the STROBE model as an agent representation and communication model designed and constructed in order to develop dynamically generated services. The shift from the currently limited perspective in service exchange scenarios to DSG is the topic addressed by this paper.…”