In spite of the growing influence of agent-based models and technologies, the event-based architectural style is still prevalent in the design of large-scale distributed applications. In this paper we discuss the role of environment in both EBS and MAS, and show how it could be used as a starting point for reconciling agent-based and event-based abstractions and techniques within a conceptually-coherent framework that could work as the foundation of a principled discipline for the engineering of complex software systems.
Interfacing the agents with their environment is a classical problem when designing multiagent systems. However, the models pertaining to this interface generally choose to either embed it in the agents, or in the environment. In this position paper, we propose to highlight the role of agent bodies as primary components of the multiagent system design. We propose a tentative definition of an agent body, and discuss its responsibilities in terms of MAS components. The agent body takes from both agent and environment: low-level agent mechanisms such as perception and influences are treated locally in the agent bodies. These mechanism participate in the cognitive process, but are not driven by symbol manipulation. Furthermore, it allows to define several bodies for one mind, either to simulate different capabilities, or to interact in the different environments - physical, social- the agent is immersed in. We also draw the main challenges to apply this concept effectively.
Ten years ago, researchers in multi-agent systems became more and more aware that agent systems consist of more than only agents. The series of workshops on Environments for Multi-Agent Systems (E4MAS 2004-2006) emerged from this awareness. One of the primary outcomes of this endeavor was a principled understanding that the agent environment should be considered as a primary design abstraction, equally important as the agents. A special issue in JAAMAS 2007 contributed a set of influential papers that define the role of agent environments, describe their engineering, and outline challenges in the field that have been the drivers for numerous follow up research efforts. The goal of this paper is to wrap up what has been achieved in the past 10 years and identify challenges for future research on agent environments. Instead of taking a broad perspective, we focus on three particularly relevant topics of modern software intensive systems: large scale, openness, and humans in the loop. For each topic, we reflect on the challenges outlined 10 years ago, present an example application that highlights the current trends, and from that outline challenges for the future. We conclude with a roadmap on how the different challenges could be tackled.
Collective Intelligence Systems (CIS), such as wikis, social networks, and content-sharing platforms, are an integral part of today's collective knowledge creation and sharing processes. CIS are complex adaptive systems, which realize environment-mediated coordination, in particular with stigmergic mechanisms. The behavior of CIS is emergent, as high-level, system-wide behavior is influenced by low-level rules. These rules are encapsulated by the CIS infrastructure that comprises in its center an actor-created artifact network that stores the shared content. In this chapter, we provide an introduction to the CIS domain, CIS architectural principles and processes. Further, we reflect on the role of CIS as multi-agent system (MAS) environments and conclude with an outlook on research challenges for CIS architectures.
Increasing interest in Collaborative Virtual Environments CVEs in different applications has imposed new requirements on the design of the CVEs and the resident Intelligent Virtual Agents IVAs. In addition to cognitive abilities, IVAs in CVEs require social and communication behaviours. The use of a Multi-Agent System MAS has been a successful approach to address the variety of evolving abilities needed by an IVA. In this paper, a model of a 'smart' CVE is presented. This CVE model publicizes the properties and the possible events of each entity located in the sensory range of the nearby IVAs. Additionally, this CVE model offers a level of abstraction for the IVAs to interact with the entities in the CVE. This level of the abstraction is distributed within the design of the resident IVAs. Moreover, this paper presents a MAS-based IVA design. This IVA is able to collaborate with humans in CVEs. The proposed model simulates humans by including input, output and processing modules. In addition, the model coordinates the IVA's verbal and non-verbal communication to convey its internal state while achieving a collaborative task.
Multiagent-based simulations enable us to validate different use-case scenarios in a lot of application domains. The idea is to develop a realistic virtual environment to test particular domain-specific procedures. This paper presents a holonic model — hierarchy of agents — of a simulated physical environment for the simulation of crowds in virtual 3D buildings. The major contributions of this paper are the agentization of the environment model to support multilevel simulation, and the definition of energy-based indicators to control the execution of the model. Finally, the application of the model inside an airport terminal is presented. It permits to validate the principles of the models and the corresponding computational gains.
SAPERE is a general multiagent framework to support the development of self-organizing pervasive computing services. One of the key aspects of the SAPERE approach is to have all interactions between agents take place in an indirect way, via a shared spatial environment. In such environment, a set of nature-inspired coordination laws have been defined to rule the coordination activities of the application agents and promote the provisioning of adaptive and self-organizing services.
Semantic Web Agents have been considered as main type of software to consume the semantic data since the Semantic Web concept was raised first time in the well-known "The Semantic Web" article in 2001. More than a decade passed and there is no collaboration between multi-agent systems and semantic web (or its current realization: linked data web) communities that can be considered important. In this paper, it is argued that initial vision was right and two communities need each other to scale up their current practice. Thus, a conceptual framework is proposed to establish necessary links between agent and linked data web infrastructures. Environment abstraction has a special role in this framework and this role is especially discussed throughout the paper.
We present here an autonomous agent-based system tightly coupled with Geographic Information Systems (GIS). Our objective is to model a city's dynamic in order to foresee both its urban evolution and the influence that the appearance of new settlements has on the overall electricity demand. This environment is deployed on a GIS-based Multi-Agent System platform where the geographical and communication components have been abstracted from the agent system onto the environment. The configuration model uses geographical information in order to improve the agents' connection and perception of their surroundings. Based on the agent's choices, we forecast urban evolution and derive the expected increment in electric consumption. We have validated our approach with real data and discuss here our conclusions.
In many application domains for agents and MAS, the interaction between the systems and human users is a main element. In some cases, the interaction occurs behind a traditional computing device, such as a computer desktop or a smartphone. In other cases, the interaction occurs through the physical world. This is the case, for instance, of smart/intelligent environment applications, and more generally in the wide context of Internet-of-Things based apps. Can the concept of agent environment for MAS play a role in the design of such systems, where humans are in the loop? In this position paper we further develop this question, providing some reflections and suggestions for future works.
Carma is a new language recently defined to support quantified specification and analysis of collective adaptive systems. It is a stochastic process algebra equipped with linguistic constructs specifically developed for modelling and programming systems that can operate in open-ended and unpredictable environments. This class of systems is typically composed of a huge number of interacting agents that dynamically adjust and combine their behaviour to achieve specific goals. A Carma model, termed a "collective", consists of a set of components, each of which exhibits a set of attributes. To model dynamic aggregations, which are sometimes referred to as "ensembles", Carma provides communication primitives based on predicates over the exhibited attributes. These predicates are used to select the participants in a communication. Two communication mechanisms are provided in the Carma language: multicast-based and unicast-based. A key feature of Carma is the explicit representation of the environment in which processes interact, allowing rapid testing of a system under different open world scenarios. The environment in Carma models can evolve at runtime, due to the feedback from the system, and it further modulates the interaction between components, by shaping rates and interaction probabilities.
Since more than a decade, the environment is seen as a key element when analyzing, developing or deploying Multi-Agent Systems (MAS) applications. Especially, for the development of multi-agent platforms it has become a key concept, similarly to many application in the area of location-based, distributed systems. An emerging, prominent application area for MAS is related to Virtual Environments. The underlying technology has evolved in a way, that these applications have grown out of science fiction novels till research papers and even real applications. Even more, current technologies enable MAS to be key components of such virtual environments. In this paper, we widen the concept of the environment of a MAS to encompass new and mixed physical, virtual, simulated, etc. forms of environments. We analyze currently most interesting application domains based on three dimensions: the way different “realities” are mixed via the environment, the underlying natures of agents, the possible forms and sophistication of interactions. In addition to this characterization, we discuss how this widened concept of possible environments influences the support it can give for developing applications in the respective domains.
Electronic institutions provide a computational analogue of human institutions to engineer open environments in which agents can interact in an autonomous way while complying with the norms of an institution. The purpose of this paper is twofold. On the one hand, we lightly survey our research on coordination infrastructures for electronic institutions in the last ten years. On the other hand, we highlight the research challenges in environment engineering that we have tackled during this journey as well as promising research paths for future research on the engineering of open environments for multi-agent systems.
Although Organization-Centered MAS OC-MAS are suitable for developing open systems for distributed and heterogeneous environments, they are still dependent on their underlying Organizational Models and associate Organizational Middleware or infrastructure to execute properly. This makes interoperability an issue worthy of consideration since agents must be able to run on different organizational infrastructures in order to interact with several OC-MAS. Such issue is closely related to the distribution of responsibilities over environment technologies and subsystems, which is still under investigation among the researchers on environments for MAS. In this paper we presented a step towards providing an environment where the knowledge of different organizational infrastructures could be available by the definition of organizational artifacts. Such artifacts are distributed throughout the environment in order to provide interoperability among agents that have different underlying organizational models, following the multiagent programming approach from the JaCaMo platform.
Environment is an essential part of any multi-agent system (MAS), since it provides the surrounding conditions for agents to exist. For some sort of systems, the environment can be viewed as providing a set of services, in which some of them, such as directory facilities, are used explicitly by the agents to perform their tasks, and other such as monitoring, behavioral enforcement and security can be done transparently by the environment. We join the idea that the specification of environments of open multi-agent systems should include laws that define what and when something can happen in an open system. Laws are restrictions imposed by the environment to tame uncertainty and to promote open system dependability. This paper proposes a design approach and application of a middleware based on laws in multi-agent systems. The approach can be viewed as a set of services provided by the environment.
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, non-rational 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 high-level, 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 TuCS oN agent coordination infrastructure.
A reference architecture integrates a set of architectural patterns that have proven their value for a family of applications. Such family of applications is characterized by specific functionality and quality requirements. A reference architecture provides a blueprint for developing software architectures for applications that share that common base. As such, a reference architecture provides a means for large-scale reuse of architectural design. This paper gives an overview of a reference architecture for situated multiagent systems we have developed in our research. We discuss various architectural views of the reference architecture. Per view, we zoom in on the main view packets, each of them containing a bundle of information of a part of the reference architecture. For each view packet we explain the rationale for the design choices that were made and we give built-in mechanisms that describe how the view packet can be exercised to build a concrete software architecture. We illustrate the use of the reference architecture with an excerpt of the software architecture of an industrial AGV transportation system.
Indirect interactions have been shown to be of interest in MultiAgent Systems (MAS), in the simulation area as well as in real applications. The environment is also emerging as a first-order abstraction. Intuitively, the environment being a common medium for the agents, it should be a suitable paradigm to provide an infrastructure for both direct and indirect interactions. However, it still lacks of a consensus on how the two relate to each other, and how the environment can support effectively notions as communication or awareness. We propose a general and operational model, Environment as Active Support of Interaction, that enables the agents to actively participate in the definition of their perceptions. Then, we show how the model provides a suitable framework for the regulation of the MAS interactions.
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.
When agents act is a common environment they leave traces. In this paper we explore the importance of using such traces as signals (stigma). Trace signals enable a flexible way to support indirect interaction between agents without adopting dedicated communication channels and signals. Although the kind of messages that can be exchanged with traces is limited, their importance for decentralized and dynamic multi-agent systems is vast. A taxonomy of trace-signals is provided and their role in different social interactions is explored. Some of the benefits and limitations of this trace-based communication are discussed.
