Chris van Aart

Self-organisation: paradigms and applications

A self-organising system functions without central control, and through contextual local interactions. Components achieve a simple task individually, but a complex collective behaviour emerges from their mutual interactions. Such a system modifies its structure and functionality to adapt to changes to requirements and to the environment based on previous experience. Nature provides examples of self-organisation, such as ants food foraging, molecules formation, or antibodies detection. Similarly, current software applications are driven by social interactions (negotiations, transactions), based on autonomous entities or agents, and run in highly dynamic environments. The issue of engineering applications, based on the principles of self-organisation to achieve robustness and adaptability, is gaining increasing interest in the software research community. The aim of this paper is to survey natural and artificial complex systems exhibiting emergent behaviour, and to outline the mechanisms enabling such behaviours.

Mobile cultural heritage guide: location-aware semantic search

In this paper we explore the use of location aware mobile devices for searching and browsing a large number of general and cultural heritage information repositories. Based on GPS positioning we can determine a users location and context, composed of physical nearby locations, historic events that have taken place there, artworks that were created at or inspired by those locations and artists that have lived or worked there. Based on a geolocation, the user has three levels of refinement: pointing to a specific heading and selection and facets and subfacets of cultural heritage objects. In our approach two types of knowledge are combined: general knowledge about geolocations and points of interest and specialized knowledge about a particular domain, i.e. cultural heritage. We use a number of Linked Open Data sources and a number of general sources from the cultural heritage domain (including Art and Architecture Thesaurus, Union List of Artist Names) as well as data from several Dutch cultural institutions. We show three concrete scenarios where a tourist accesses localized information on his iPhone about the current environment, events, artworks or persons, which are enriched by Linked Open Data sources. We show that Linked Open Data sources in isolation are currently too limited to provide interesting semantic information but combined with each other and with a number of other sources a really informative location-based service can be created.

Organizational building blocks for design of distributed intelligent system

In this work we present a framework for multi-agent system design which is based both on human organizational notions and principles for distributed intelligent systems design. The framework elaborates on the idea that notions from the field of organizational design can be used as the basis for the design of distributed intelligent systems. Concepts such as task, control, job, operation, management, coordination and organization are framed into an agent organizational framework. A collection of organizational design activities is presented that assist in a task oriented decomposition of the overall task of a system into jobs and the reintegration of jobs using job allocation, coordination mechanisms and organizational structuring. A number of coordination mechanisms have been defined in the organizational design literature. For the scope of this work we concentrate on: Direct Supervision where one individual takes all decisions about the work of others, Mutual Adjustment that achieves coordination by a process of informal communication between agents, and Standardization of Work, Output and Skills. Three organizational structures are discussed, that coordinate agents and their work: Machine Bureaucracy, Professional Bureaucracy and Adhocracy. The Machine Bureaucracy is task-driven, seeing the organization as a single-purpose structure, which only uses one strategy to execute the overall task. The Professional Bureaucracy is competence-driven, where a part of the organization will first examine a case, match it to predetermined situations and then allocate specialized agents to it. In the Adhocracy the organization is capable of reorganizing its own structure including dynamically changing the work flow, shifting responsibilities and adapting to changing environments. A case study on distributed supply chain management shows the process from task decomposition via organizational design to three multi-agent architectures based on Mintzbergs organizational structures.

RadioMarché: distributed voice- and web-interfaced market information systems under rural conditions

Despite its tremendous success, the World Wide Web is still inaccessible to 4.5 billion people - mainly in developing countries - who lack a proper internet infrastructure, a reliable power supply, and often the ability to read and write. Hence, alternative or complementary technologies are needed to make the Web accessible to all, given the limiting conditions. These technologies must serve a large audience, who then may start contributing to the Web by creating content and services. In this paper we propose RadioMarche, a voice- and web-based market information system aimed at stimulating agricultural trade in Sahel countries. To overcome interfacing and infrastructural issues, RadioMarche has a mobile-voice interface and is easy to deploy. Furthermore, we will show how data from regionally distributed instances of RadioMarche, can be aggregated and exposed using Linked Data approaches, so that new opportunities for product and service innovation in agriculture and other domains can be unleashed.

Voice-based web access in rural Africa

Despite its tremendous success, the World Wide Web can still not used by large parts of the worlds population. Therefore, many people, especially in rural areas of developing countries, still do not have access to services and information that are available as a result of the World Wide Web. Given the potential of the Web in improving peoples lives, a question is how it can be expanded to serve those living in less privileged conditions. Information must then be reachable regardless of infrastructure, allowing access using also interfaces such as radio and mobile phone. There is widespread use and adoption of radio and mobile telephony in Africa and thus, innovative use of these technologies could help in expanding the reach of the Web. In this paper we present three systems, based on open Web standards, designed and built to fit conditions in remote rural regions in Africa namely, a voice-based (i) trading system, using phone and radio as its interfaces, (ii) a voice-web based interactive news and blogging system and (iii) messaging system. The systems have been developed and have been deployed in Mali. All three systems together showcase the importance that innovation plays in order to make Web technologies relevant in the lives of many rural dwellers in Africa. We show the current status and usage of the systems and discuss how these systems represent our steps into bringing the Web to these contexts.

A dialogue with linked data: Voice-based access to market data in the Sahel

The Linked Data movement has facilitated efficient data sharing in many domains. However, people in rural developing areas are mostly left out. Lack of relevant content and suitable interfaces prohibit potential users in rural communities to produce and consume Linked Data. In this paper, we present a case study exposing locally produced market data as Linked Data, which shows that Linked Data can be meaningful in a rural, development context. We present a way of enriching the market data with voice labels, allowing for the development of applications that (re-)use the data in voice-based applications. Finally, we present a prototype demonstrator that provides access to this linked market data through a voice interface, accessible to first generation mobile phones.

Use case and requirements analysis in a remote rural context in mali

[Context & motivation] Few studies have reported on a systematic use case and requirements analysis of low-tech, low-resource contexts such as rural Africa. This, despite the widespread agreement on the importance of Information and Communication Technologies (ICT) for social and rural development, and despite the large number of ICT projects targeting underprivileged communities. [Question/problem] Unfamiliarity with the local context and differences in cultural and educational backgrounds between end-users and software engineers are the challenges for requirements engineering (RE) we encountered. [Principal ideas/results] We describe a systematic approach to RE in developing areas, based on the Living Lab methodology. Our approach is supported by extensive field research and based on co-creation within a multi-disciplinary and multi-cultural team of developers and users. This approach creates a shared understanding of the problem and its local context, and optimizes communication. [Contribution] We illustrate the approach using a case study of web- and voice-based communication services, that we developed for a rural context in Mali.

Voice-based marketing for agricultural products: a case study in rural Northern Ghana

We present a study conducted in rural Northern Ghana about issues around the marketing of agricultural products and the need of mobile-based ICT solutions. The need for the spread of information and web access to communities in developing countries has given rise to the design and development of numerous ICT solutions, many of which have focused on the recent increase of mobile usage in developing countries. The contributions of this paper are: 1) Empirical results from a field survey run in Northern Ghana, which points to issues of a lack of buyers, low price offers and lack of transportation to sale points as the main issues in marketing of agricultural products and also points to the potential for mobile-based ICT solutions to mitigate the pertinent issues within the case study, but also in other areas. 2) The development of a voice-based prototype that allows medium to large-scale farmers in rural areas to place advertisements on the World Wide Web. The prototype was evaluated based on functionality and feasibility, including financial sustainability.

The Web of Radios - Introducing African Community Radio as an Interface to the Web of Data

The World Wide Web as it is currently deployed can only be accessed using modern client devices and graphical interfaces, within an infrastructure compassing datacenters and reliable, high-speed Internet connections. However, in many regions in developing countries these conditions are absent. Many people living in remote rural areas in developing countries will not be able to use the Web, unless they can produce and consume voice-based content using alternative interfaces such as (2G) mobile phone, and radio. In this paper we introduce a radio platform, based on a use case and requirements analysis of community radio stations in Mali. The voice-based content of this radio platform will be made publicly available, using Linked Data principles, and will be ready for unexpected re-use. It will help to bring the benefits of the Web to people who are out of reach of computers and the Internet.

Web services negotiation in an insurance grid

There are an increasing number of initiatives for the migration of agents research towards new Internet technologies such as the semantic web, Grid, and web services. On the one hand, service oriented Grid architectures need to support dynamic cooperation, negotiation and coordination between web services controlling Grid resources, for efficient resource and task allocation and execution. On the other hand, the Grid can facilitate agent communication, life-cycle management, and access to resources for agents. The insurance sector is one such area that would benefit from the automation brought by multi-agent systems techniques in handling claims and detecting fraudulent cases. In this paper, we discuss our work on facilitating dynamic and adaptive negotiation between web and grid services. We describe our deployed approach in an InsuranceGrid, which manages businesses involved in dealing with car damage claims for a number of insurance companies.