Signifiers as a First-class Abstraction in Hypermedia Multi-Agent Systems

Hypermedia APIs enable the design of reusable hypermedia clients that discover and exploit affordances on the Web. However, the reusability of such clients remains limited since they cannot plan and reason about interaction. This paper provides a conceptual bridge between hypermedia-driven affordance exploitation on the Web and methods for representing and reasoning about actions that have been extensively explored for Multi-Agent Systems (MAS) and, more broadly, Artificial Intelligence. We build on concepts and methods from Affordance Theory and Human-Computer Interaction that support interaction efficiency in open and evolvable environments to introduce signifiers as a first-class abstraction in Web-based MAS: Signifiers are designed with respect to the agent-environment context of their usage and enable agents with heterogeneous abilities to act and to reason about action. We define a formal model for the contextual exposure of signifiers in hypermedia environments that aims to drive affordance exploitation. We demonstrate our approach with a prototypical Web-based MAS where two agents with different reasoning abilities proactively discover how to interact with their environment by perceiving only the signifiers that fit their abilities. We show that signifier exposure can be inherently managed based on the dynamic agent-environment context towards facilitating effective and efficient interactions on the Web

Position Paper for the Second W3C Workshop on the Web of Things

International audienceInteraction Affordances are central to the W3C Web of Things (WoT): they allow Consumers to identify and use the capabilities provided by Web Things. 1 Ideally, interaction affordances would allow consumers to arrive-and-operate in any W3C WoT environment: given an entry URI, consumers would be able to achieve their tasks in an autonomous manner by navigating the hypermedia and deciding among the various options presented to them at run time. A central challenge then, which is not typically within the scope of Web engineering , is how to design, program, debug, monitor, and regulate such autonomous consumers of Web Things. The engineering of similar autonomous systems has been studied to a large extent in research on multi-agent systems (MAS), and we believe that tapping into the large body of MAS research holds great promise for unlocking the full potential of the W3C WoT. In this position paper, we motivate and present our vision for autonomous systems in the WoT, and support this vision with a prototype for industrial manufacturing. We then discuss some of the challenges and opportunities raised by bringing autonomy to the WoT

Adding a Social Dimension to the Web of Things

International audienceThe Internet of Things (IoT) has rapidly gained ground in recent years. Furthermore, researchers are looking at extending the current Web standards for refining the IoT into what is called the Web of Things. Most of the research work conducted so far in this direction resulted in one-off prototypes, yet more interesting problems arise when these Web-enabled devices come to interact with one another. In this paper we describe our vision for a Social Web of Things, as a means for interconnecting every "thing" in a scalable and effective way. We motivate this vision and we position our work with respect to current approache

Autonomous search in a social and ubiquitous Web

International audienceRecent W3C recommendations for the Web of Things (WoT) and the Social Web are turning hypermedia into a homogeneous information fabric that interconnects heterogeneous resources: devices, people, information resources,abstract concepts, etc. The integration of multi-agent systems with such hypermedia environments now provides a means to distribute autonomous behavior in worldwide pervasive systems. A central problem then is to enable autonomous agents to discover heterogeneous resources in world wide and dynamic hypermedia environments. This is a problem in particular in WoT environments that rely on open standards and evolve rapidly—thus requiring agents to adapt their behavior at runtime in pursuit of their design objectives. To this end, we developed a hypermedia search engine for the WoT that allows autonomous agents to perform approximate search queries in order to retrieve relevant resources in their environment in(weak) real time. The search engine crawls dynamic WoT environments to discover and index device metadata described with the W3C WoT Thing Description, and exposes a SPARQL endpoint that agents can use for approximate search. To demonstrate the feasibility of our approach, we implemented a prototype application for the maintenance of industrial robots in worldwide manufacturing systems. The prototype demonstrates that our semantic hypermedia search engine enhances the flexibility and agility of autonomous agents in a social and ubiquitous Web

Engineering Multi-Agent Systems: State of Affairs and the Road Ahead

The continuous integration of software-intensive systems together with the ever-increasing computing power offer a breeding ground for intelligent agents and multi-agent systems (MAS) more than ever before. Over the past two decades, a wide variety of languages, models, techniques and methodologies have been proposed to engineer agents and MAS. Despite this substantial body of knowledge and expertise, the systematic engineering of large-scale and open MAS still poses many challenges. Researchers and engineers still face fundamental questions regarding theories, architectures, languages, processes, and platforms for designing, implementing, running, maintaining, and evolving MAS. This paper reports on the results of the 6th International Workshop on Engineering Multi-Agent Systems (EMAS 2018, 14th-15th of July, 2018, Stockholm, Sweden), where participants discussed the issues above focusing on the state of affairs and the road ahead for researchers and engineers in this area

Weaving a Social Web of Things : Enabling Autonomous and Flexible Interaction in the Internet of Things

L’Internet des Objets (IoT) vise à créer un eco-système global et ubiquitaire composé d’un grand nombre d’objets hétérogènes. Afin d’atteindre cette vision, le World Wide Web apparaît comme un candidat adapté pour interconnecter objets et services à la couche applicative en un Web des Objets (WoT).Cependant l’évolution actuelle du WoT produit des silos d’objets et empêche ainsi la mise en place de cette vision. De plus, même si le Web facilite la composition d’objets et services hétérogènes, les approches existantes produisent des compositions statiques incapables de s’adapter à des environnements dynamiques et des exigences évolutives. Un autre défi est à relever: permettre aux personnes d’interagir avec le vaste, évolutif et hétérogène IoT.Afin de répondre à ces limitations, nous proposons une architecture pour IoT ouvert et autogouverné, constitué de personnes et d’objets situés, en interaction avec un environnement global via des plateformes hétérogènes. Notre approche consiste de rendre les objets autonomes et d’appliquer la métaphore des réseaux sociaux afin de créer des réseaux flexibles de personnes et d’objets. Nous fondons notre approche sur les résultats issus des domaines des multi-agents et du WoT afin de produit un WoT Social.Notre proposition prend en compte les besoins d’hétérogénéité, de découverte et d’interaction flexible dans l’IoT. Elle offre également un coût minimal pour les développeurs et les utilisateurs via différentes couches d’abstraction permettant de limité la complexité de cet éco-système. Nous démontrons ces caractéristiques par la mise en oeuvre de plus scénarios applicatifs.The Internet of Things (IoT) aims to create a global ubiquitous ecosystem composed of large numbers of heterogeneous devices. To achieve this vision, the World Wide Web is emerging as a suitable candidate to interconnect IoT devices and services at the application layer into a Web of Things (WoT).However, the WoT is evolving towards large silos of things, and thus the vision of a global ubiquitous ecosystem is not fully achieved. Furthermore, even if the WoT facilitates mashing up heterogeneous IoT devices and services, existing approaches result in static IoT mashups that cannot adapt to dynamic environments and evolving user requirements. The latter emphasizes another well-recognized challenge in the IoT, that is enabling people to interact with a vast, evolving, and heterogeneous IoT.To address the above limitations, we propose an architecture for an open and self-governed IoT ecosystem composed of people and things situated and interacting in a global environment sustained by heterogeneous platforms. Our approach is to endow things with autonomy and apply the social network metaphor to createflexible networks of people and autonomous things. We base our approach on results from multi-agent and WoT research, and we call the envisioned IoT ecosystem the Social Web of Things.Our proposal emphasizes heterogeneity, discoverability and flexible interaction in the IoT. In the same time, it provides a low entry-barrier for developers and users via multiple layers of abstraction that enable them to effectively cope with the complexity of the overall ecosystem. We implement several application scenarios to demonstrate these features

Tisser le Web Social des Objets : Permettre une Interaction Autonome et Flexible dans l’Internet des Objets

The Internet of Things (IoT) aims to create a global ubiquitous ecosystem composed of large numbers of heterogeneous devices. To achieve this vision, the World Wide Web is emerging as a suitable candidate to interconnect IoT devices and services at the application layer into a Web of Things (WoT).However, the WoT is evolving towards large silos of things, and thus the vision of a global ubiquitous ecosystem is not fully achieved. Furthermore, even if the WoT facilitates mashing up heterogeneous IoT devices and services, existing approaches result in static IoT mashups that cannot adapt to dynamic environments and evolving user requirements. The latter emphasizes another well-recognized challenge in the IoT, that is enabling people to interact with a vast, evolving, and heterogeneous IoT.To address the above limitations, we propose an architecture for an open and self-governed IoT ecosystem composed of people and things situated and interacting in a global environment sustained by heterogeneous platforms. Our approach is to endow things with autonomy and apply the social network metaphor to createflexible networks of people and autonomous things. We base our approach on results from multi-agent and WoT research, and we call the envisioned IoT ecosystem the Social Web of Things.Our proposal emphasizes heterogeneity, discoverability and flexible interaction in the IoT. In the same time, it provides a low entry-barrier for developers and users via multiple layers of abstraction that enable them to effectively cope with the complexity of the overall ecosystem. We implement several application scenarios to demonstrate these features.L’Internet des Objets (IoT) vise à créer un eco-système global et ubiquitaire composé d’un grand nombre d’objets hétérogènes. Afin d’atteindre cette vision, le World Wide Web apparaît comme un candidat adapté pour interconnecter objets et services à la couche applicative en un Web des Objets (WoT).Cependant l’évolution actuelle du WoT produit des silos d’objets et empêche ainsi la mise en place de cette vision. De plus, même si le Web facilite la composition d’objets et services hétérogènes, les approches existantes produisent des compositions statiques incapables de s’adapter à des environnements dynamiques et des exigences évolutives. Un autre défi est à relever: permettre aux personnes d’interagir avec le vaste, évolutif et hétérogène IoT.Afin de répondre à ces limitations, nous proposons une architecture pour IoT ouvert et autogouverné, constitué de personnes et d’objets situés, en interaction avec un environnement global via des plateformes hétérogènes. Notre approche consiste de rendre les objets autonomes et d’appliquer la métaphore des réseaux sociaux afin de créer des réseaux flexibles de personnes et d’objets. Nous fondons notre approche sur les résultats issus des domaines des multi-agents et du WoT afin de produit un WoT Social.Notre proposition prend en compte les besoins d’hétérogénéité, de découverte et d’interaction flexible dans l’IoT. Elle offre également un coût minimal pour les développeurs et les utilisateurs via différentes couches d’abstraction permettant de limité la complexité de cet éco-système. Nous démontrons ces caractéristiques par la mise en oeuvre de plus scénarios applicatifs

Repurposing Manufacturing Lines on the Fly with Multi-agent Systems for the Web of Things

International audienceMulti-agent systems (MAS) have long been envisioned as a key enabling technology in manufacturing, but this promise is yet to be realized: the lack of proper models, architectures, tooling, and the high level of expertise required for designing and programming agent-based manufacturing systems have hindered their large-scale acceptance. The emerging Web of Things (WoT), now being standardized at the W3C and IETF, provides new research opportunities that could help MAS enter the mainstream. In this paper, we present an approach to design scalable and flexible agent-based manufacturing systems that integrates automated planning with multi-agent oriented programming for the WoT: autonomous agents synthesize production plans using semantic descriptions of Web-based artifacts and coordinate with one another via multi-agent organizations; engineers can program and repurpose the systems on the fly via an intuitive Web user interface. The systems use the Web as an application architecture (and not just as a transport layer), which facilitates the seamless integration of geographically distributed production cells. To demonstrate our approach, we implemented a prototypical production cell that uses industry-grade robots and an augmented reality interface for human workers. Together, these contributions demonstrate a means to achieve an intriguing vision for the forthcoming fourth industrial revolution: a global collective intelligence for manufacturing

Executive Summary

International audienceThe vision of autonomous agents on the Web is almost as old as the Web itself: in his keynote at WWW’941 , Sir Tim Berners-Lee was noting that documents on the Web describe real objects and relationships among them, and if the semantics of these objects are represented explicitly then machines can browse through and manipulate reality.2 These ideas were published under the Semantic Web vision in 2001 [1]. Yet in 2007, after having spent the better half of a decade advancing this vision, James Hendler was looking back to conclude that most ideas in the original article were already seeing widespread deployment on the Web except for agent-based systems – and raised the question: “where are all the intelligent agents?” [2]

Agents on the Web (Dagstuhl Seminar 23081) : Executive Summary

International audienceThe recent evolution towards hypermedia-driven services, Linked Data, and the Web of Things is turning the Web into a homogeneous hypermedia fabric that interconnects everything – devices, physical objects, documents, or abstract concepts. The latest standards on the Web of Things and (Social) Linked Data allow automated software clients to navigate, query, observe, and act on this uniform hypermedia fabric. Use cases that have long been envisioned for artificial agents on the Web – as published in the original Semantic Web vision in 2001 and going back to the early days of the Internet – are now closer to their practical implementation and deployment. Nevertheless, the engineering of such modern Web-based systems poses research challenges that have yet to be addressed