Actions Made Explicit in BDI

The Belief, Desire, Intention (BDI) architecture is increasingly being used in a wide range of complex applications for agents. Many theories and models exists which support this architecture and the recent version is that of capability being added as an additional construct. In all these models the concept of action is seen in an endogenous manner. We argue that the result of an action performed by an agent is extremely important when dealing with composite actions and hence the need for an explicit representation of them. The capability factor is supported using a RES construct and it is shown how the components of a composite action is supported using these two. Further, we introduce an OPP (opportunity) operator which in alliance with result and capability provides a better semantics for practical reasoning in BDI

A multi-agent system with application in project scheduling

The new economic and social dynamics increase project complexity and makes scheduling problems more difficult, therefore scheduling requires more versatile solutions as Multi Agent Systems (MAS). In this paper the authors analyze the implementation of a Multi-Agent System (MAS) considering two scheduling problems: TCPSP (Time-Constrained Project Scheduling), and RCPSP (Resource-Constrained Project Scheduling). The authors propose an improved BDI (Beliefs, Desires, and Intentions) model and present the first the MAS implementation results in JADE platform.multi-agent architecture, scheduling, project management, BDI architecture, JADE.

Feeling happy when feeling down : the effectiveness of positive mental imagery in dysphoria

Background and objectives Mental imagery can evoke strong emotional responses, but imagery perspective can influence the response, with observer perspective reducing emotionality. This is important provided that positive imagery can be an effective mood repairing strategy in healthy individuals. However, (sub-clinical) depressed individuals tend to spontaneously adopt an observer perspective. We investigated whether positive imagery would result in a similar emotional response in dysphoric and non-dysphoric individuals when instructed and trained to use field perspective imagery. Additionally, we compared the emotional response in dysphoric individuals who received instructions to dysphoric individuals who received no instructions on processing mode during positive memory recall. Methods Dysphoric and non-dysphoric individuals completed a mood induction procedure imagining positive or neutral memories. They received instructions and practice in the use of field perspective imagery. An additional control group of dysphoric individuals recalled positive memories without receiving instructions on processing mode. Results Dysphoric and non-dysphoric individuals who received instructions on field perspective imagery reported similar use of field and observer perspective imagery, and a similar positive emotional response. Dysphoric individuals who did not receive specific instructions, as compared to those who did, reported greater use of observer perspective and lower levels of positive affect afterwards. Limitations A dysphoric sample limits generalization to clinically depressed individuals, although these individuals are at risk for developing depression. However, mental imagery used in relapse prevention is likely targeting sub-clinical populations. Conclusions Providing practice in field perspective imagery could potentially improve the effectiveness of positive memory recall as a mood repair strategy in (sub-clinically) depressed individuals, and may therefore have important therapeutic benefits.</p

Commercial software tools for intelligent autonomous systems

This article identifies some of the commercial software tools that can potentially be examined, or relied upon for their techniques, within new EPSRC projects entitled "Reconfigurable Autonomy" and "Distributed Sensing and Control.." awarded and to be undertaken between Liverpool, Southampton and Surrey Universities in the next 4 years. Although such projects strive to produce new techniques of various kinds, the software reviewed here could also influence, shape and help to integrate the algorithmic outcome of all 16 projects awarded within the EPSRC Autonomous and Intelligent Systems programme early 2012. To avoid mis-representation of technololgies provided by the software producer companies listed, most of this review is based on using quotes from original product descriptions

Programming in logic without logic programming

In previous work, we proposed a logic-based framework in which computation is the execution of actions in an attempt to make reactive rules of the form if antecedent then consequent true in a canonical model of a logic program determined by an initial state, sequence of events, and the resulting sequence of subsequent states. In this model-theoretic semantics, reactive rules are the driving force, and logic programs play only a supporting role. In the canonical model, states, actions and other events are represented with timestamps. But in the operational semantics, for the sake of efficiency, timestamps are omitted and only the current state is maintained. State transitions are performed reactively by executing actions to make the consequents of rules true whenever the antecedents become true. This operational semantics is sound, but incomplete. It cannot make reactive rules true by preventing their antecedents from becoming true, or by proactively making their consequents true before their antecedents become true. In this paper, we characterize the notion of reactive model, and prove that the operational semantics can generate all and only such models. In order to focus on the main issues, we omit the logic programming component of the framework.Comment: Under consideration in Theory and Practice of Logic Programming (TPLP

Social Mental Shaping: Modelling the Impact of Sociality on Autonomous Agents' Mental States

This paper presents a framework that captures how the social nature of agents that are situated in a multi-agent environment impacts upon their individual mental states. Roles and relationships provide an abstraction upon which we develop the notion of social mental shaping. This allows us to extend the standard Belief-Desire-Intention model to account for how common social phenomena (e.g. cooperation, collaborative problem-solving and negotiation) can be integrated into a unified theoretical perspective that reflects a fully explicated model of the autonomous agent's mental state