Mirko Viroli

Artifacts in the A&A meta-model for multi-agent systems

In this article we focus on the notion of artifact for agents in multi-agent systems (MAS) as a basis for a new meta-model promoting the modelling and engineering of agent societies and MAS environment as first-class entities. Its conceptual foundations lay upon theories and results coming from computational sciences as well as from organisational and cognitive sciences, psychology, computer supported cooperative work (CSCW), anthropology and ethology. In the resulting agents & artifacts (A&A) meta-model, agents are the (pro-)active entities in charge of the goals/tasks that altogether build up the whole MAS behaviour, whereas artifacts are the reactive entities providing the services and functions that make individual agents work together in a MAS, and that shape agent environment according to the MAS needs. After presenting the scientific background, we define the notions of artifact in the A&A meta-model, discuss how it affects the notion of intelligence in MAS, and show its application to a number of agent-related research fields.

Environment programming in multi-agent systems: an artifact-based perspective

This article introduces the notion of environment programming in software multi-agent systems (MAS) and describes a concrete computational and programming model based on the artifact abstraction and implemented by the CArtAgO framework. Environment programming accounts for conceiving the computational environment where agents are situated as a first-class abstraction for programming MAS, namely a part of the system that can be designed and programmed—aside to agents—to encapsulate functionalities that will be exploited by agents at runtime. From a programming and software engineering perspective, this is meant to improve the modularity, extensibility and reusability of the MAS as a software system. By adopting the A&A meta-model, we consider environments populated by a dynamic set of computational entities called artifacts, collected in workspaces. From the agent viewpoint, artifacts are first-class entities of their environment, representing resources and tools that they can dynamically instantiate, share and use to support individual and collective activities. From the MAS programmer viewpoint, artifacts are a first-class abstraction to shape and program functional environments that agents will exploit at runtime, including functionalities that concern agent interaction, coordination, organisation, and the interaction with the external environment. The article includes a description of the main concepts concerning artifact-based environments and related CArtAgO technology, as well as an overview of their application in MAS programming.

Description and composition of bio-inspired design patterns: a complete overview

In the last decade, bio-inspired self-organising mechanisms have been applied to different domains, achieving results beyond traditional approaches. However, researchers usually use these mechanisms in an ad-hoc manner. In this way, their interpretation, definition, boundary (i.e. when one mechanism stops, and when another starts), and implementation typically vary in the existing literature, thus preventing these mechanisms from being applied clearly and systematically to solve recurrent problems. To ease engineering of artificial bio-inspired systems, this paper describes a catalogue of bio-inspired mechanisms in terms of modular and reusable design patterns organised into different layers. This catalogue uniformly frames and classifies a variety of different patterns. Additionally, this paper places the design patterns inside existing self-organising methodologies and hints for selecting and using a design pattern.

CArtAgO: a framework for prototyping artifact-based environments in MAS

This paper describes CArtAgO, a framework for developing artifact-based working environments for multiagent systems (MAS). The framework is based on the notion of artifact, as a basic abstraction to model and engineer objects, resources and tools designed to be used and manipulated by agents at run-time to support their working activities, in particular the cooperative ones. CArtAgO enables MAS engineers to design and develop suitable artifacts, and to extend existing agent platforms with the possibility to create artifact-based working environments, programming agents to exploit them. In this paper, first the abstract model and architecture of CArtAgO is described, then a first Java-based prototype technology is discussed.

Environment Programming in CArtAgO

CArtAgO is a platform and infrastructure providing ageneral-purpose programming model for building shared computational worlds – referred here as work environments – that agents, possibly belonging to heterogeneous agent platforms, can exploit to work together inside a Multi-Agent System. Being based on the A&A (Agents and Artifacts) conceptual model, CArtAgO work environments are modelled and engineered interms of set of artifacts programmed by MAS designers, collected in workspaces. From the agent view point, artifacts are first-class entities representing resources and tools that agents can dynamically instantiate, share and use to support their individual and collective activities. After describing the basic motivations behind the approach, the chapter provides an overview of the programming model promoted by CArtAgO for the definition of artifacts (MAS designer’s viewpoint)and for the use of artifacts(agent’s viewpoint), using Jason as reference platform for MAS programming.

Cognitive stigmergy: towards a framework based on agents and artifacts

Stigmergy has been adopted in MAS (multi-agent systems) and in other fields as a technique for realising forms of emergent coordination in societies composed by a large amount of ant-like, nonrational agents. In this paper we discuss a conceptual (and engineering) framework for exploring the use of stigmergy in the context of societies composed by cognitive / rational agents, as a means for supporting highlevel, knowledge-based social activities.multi-agent We refer to this kind of stigmergy as cognitive stigmergy. Cognitive stigmergy is based on the use of artifacts as tools populating and structuring the agent working environment, and which agents perceive, share and rationally use for their individual goals. Artifacts are environment abstractions that mediate agent interaction and enable emergent coordination: as such, they can be used to encapsulate and enact the stigmergic mechanisms and the shared knowledge upon which emergent coordination processes are based. In this paper, we start exploring this scenario introducing an agent-based framework for cognitive stigmergy based on artifacts. After discussing the main conceptual issues--the notion of cognitive stigmergy and the role of artifacts--, we sketch an abstract architecture for cognitive stigmergy, and outline its implementation upon the TuCSoN agent coordination infrastructure.

Give agents their artifacts: the A&A approach for engineering working environments in MAS

In human society, almost any cooperative working context accounts for different kinds of object, tool, artifacts in general, that humans adopt, share and intelligently exploit so as to support their working activities, in particular social ones. According to theories in human sciences--Activity Theory and Distributed Cognition are two main examples [5, 4]--and to related disciplines in computer science--such as Computer Supported Cooperative Work (CSCW) and Human-Computer Interaction (HCI)--such entities have a key role in determining the success or failure of the activities, playing an essential function in simplifying complex tasks and--more generally--in designing solutions that scale with activity complexity. Such a perspective can be found also in some works in the context of Distributed Artificial Intelligence [1, 2]. Analogously to the human case, we claim that also (cognitive) multiagent systems (MAS) could greatly benefit from the definition and systematic exploitation of a suitable notion of working environment, composed by different sorts of artifacts, dynamically constructed, shared and used by agents to support their working activities. Along this line, in this paper first we introduce a conceptual framework called A&A (Agents and Artifacts) which aims at directly modelling and engineering working environments in the context of cognitive multiagent systems; then, we provide a brief overview of the basic technologies that support such an approach, CARTAGO in particular--a Java-based framework for engineering working environments to be integrated with heterogeneous agent platforms. Such a perspective is strenghtened by recent efforts in AOSE (Agent-Oriented Software Engineering) that remark the fundamental role of the environment for the engineering of MAS [8]. The A&A framework can be considered an instance of such approaches, with some specific peculiarity: (i) abstractions and generality---the aim is to find a basic set of conceptual abstractions and related theory which, analogously to the agent abstraction, could be general enough to be the basis to define concrete architectures and programming environments, but specific enough to capture the essential properties of systems; (ii) cognitive---analogous to designed environment in human society, the properties of such environment abstractions should be conceived to be suitably and effectively exploited by cognitive agents, as intelligent constructors / users / manipulators of the environment. The work presented in this paper generalises and extends our previous work focussed on coordination artifacts presented at [6], and more recent works about the notion of artifact [7].

Spatial Coordination of Pervasive Services through Chemical-Inspired Tuple Spaces

To support and engineer the spatial coordination of distributed pervasive services, we propose a chemical-inspired model, which extends tuple spaces with the ability of evolving tuples mimicking chemical systems, that is, in terms of reaction and diffusion rules that apply to tuples modulo semantic match. The suitability of this model is studied by considering a self-adaptive display infrastructure providing people nearby with several visualization services (advertisements, news, personal and social content). The key result of this article is that general-purpose chemical reactions inspired by population dynamics can be used in pervasive applications to enact spatial computing patterns of competition and gradient-based interaction.

Programming MAS with artifacts

This paper introduces the notion of artifact as a first-class ion in MASs (multi-agent systems) and focuses on its impact on MAS programming. Artifacts are runtime devices providing some kind of function or service which agents can fruitfully use - both individually and collectively - to achieve their individual as well as social objectives. Artifacts can be conceived (and programmed) as basic building blocks to model and build agent (working) environments. Besides introducing a conceptual and modelling framework, the paper discusses the impact of this new notion on MAS programming, focussing in particular on MAS composed by cognitive agents. To make the discussion more concrete, we provide an example scenario featuring 3APL agents whose coordination activity is supported by TuCSoN tuple centres - an existing coordination model providing some of the basic properties of artifacts for MASs.

Agens Faber: Toward a Theory of Artefacts for MAS

Human intelligence has evolved along with the use of more and more sophisticated tools, allowing Homo Faber (from Homo Habilis to Homo Sapiens Sapiens) to cope with environment changes, as well as to adapt the environment to his needs. Analogously, in this seminal paper we introduce the notion of Agens Faber, conveying the idea that agent intelligence should not be considered as separated by the agent ability to perceive and affect the environment-and so, that agent intelligence is strictly related to the artefacts that enable, mediate and govern any agent (intelligent) activity. Along this line, we first discuss the notion of artefact for MAS in general, then we try to devise out the admissible / required / desirable features of an artefact for MAS. We elaborate on the many sorts of possible relations between agents and artefacts, focusing in particular on the issue of the rational exploitation of artefacts, and also rough out a possible taxonomy of artefacts for MAS.