Invited Talks :

Elisabeth André

Universität Augsburg

"From Simulated Dialogues to Interactive Performances with Virtual Actors"

In my talk, I will argue in favor of a shift from applications with single presentation agents towards flexible performances given by a team of characters as a new presentation style. Infotainment and edutainment transmissions on TV as well as advertisement clips are examples that demonstrate how information can be conveyed in an appealing manner by multiple presenters with complementary characters and role castings. However, our approach distinguishes from conventional TV presentations by at least two features: adaptivity and interactivity. I will illustrate the approach by means of various academic and industrial projects we conduced at DFKI GmbH and at Augsburg University. In the first group of systems, the attribute "flexibe" refers to the system's ability to adapt a presentation to the needs and preferences of a particular user. In the second group of systems, flexibility additionally refers to the user's option of actively participating in a computer-based performance and influencing the behavior of the involved characters at runtime. While a plan-based approach has proven appropriate in both versions to automatically control the behavior of the agents, the second group of systems calls for highly reactive and distributed behavior planning.

Elisabeth André is a full professor of computer science at the University of Augsburg, Germany. Prior to that, she was working as a principal researcher at DFKI GmbH. She is the Chair of the ACL Special Interest Group on Multimedia Language Processing (SIGMEDIA). Furthermore, she is on the Editorial Board of Artificial Intelligence Communications (AICOM), Cognitive Processing (International Quarterly of Cognitive Science), Universal Access to the Information Society (UAIS), the Area Editor for Intelligent User Interfaces of the Electronic Transactions of Artificial Intelligence (ETAI), and a member of the editorial board of Computational Linguistics for the period of 2002-2004. Her research interests include: embodied conversational agents, operational models of personality and emotion, multimodal dialogue systems and multimedia authoring.

Michael Wooldridge

University of Liverpool

"Time, Knowledge, and Cooperation: Alternating-time Temporal Epistemic Logic and its Applications"

Branching-time temporal logics have proved to be an extraordinarily successful tool in the formal specification and verification of distributed systems. Much of this recent success stems from the tractability of the model checking problem for the branching time logic CTL. Several successful verification tools (of which SMV is the best known) have been implemented that allow designers to verify that systems satisfy requirements expressed in CTL. Recently, CTL was generalised by Alur, Henzinger, and Kupferman in a logic known as "Alternating-time Temporal Logic" (ATL). The key insight in ATL is that the path quantifiers of CTL could be replaced by "cooperation modalities", of the form < < G > >, where G is a set of agents. The intended interpretation of an ATL formula < < G > > φ is that the agents G can cooperate to ensure that φ holds (equivalently, that G have a winning strategy for φ). It turns out that the resulting logic very naturally generalises and extends CTL. In this talk, I will discuss extensions to ATL with knowledge modalities, of the kind made popular by the work of Fagin, Halpern, Moses, and Vardi. Combining these knowledge modalities with ATL, it becomes possible to express such properties as "group G can cooperate to bring about φ iff it is common knowledge in G that φ". The resulting logic -- Alternating-time Temporal Epistemic Logic (ATEL) -- has a range of applications, which will be discussed in the talk. In addition, I will relate some preliminary experiments with ATEL model checking, which shares the tractability property of its ancestor CTL. (This talk reports joint work with Wiebe van der Hoek.)

Michael Wooldridge is Professor of Computer Science in the Department of Computer Science at the University of Liverpool, UK. He has been active in the research and development of multi-agent systems for ten years, gaining his PhD for work in the theoretical foundations of multi-agent systems from the University of Manchester, UK in 1992. Prof Wooldridge has published over a hundred articles in the theory and practice of agent-based systems, has edited nine books in the area, and published a monograph entitled "Reasoning about Rational Agents" (MIT Press, 2000); his textbook "An Introduction to Multiagent Systems" (Wiley) was published in 2002. He has served on many program committees for conferences and workshops in the area, and is a director of the International Foundation for Multi-Agent Systems (IFMAS). He also serves as editor in chief of the International Journal of Autonomous Agents and Multi-Agent Systems (Kluwer), and an editorial board member for the Journal of Applied AI (Taylor & Francis). He is founder and associate coordinator of AgentLink, the ESPRIT-funded European Network of Excellence in the area ofagent-based computing (see

Dieter Fensel

Vrije Universiteit Amsterdam

"Semantic Web Enabled Web Services"

Currently, computers are changing from single, isolated devices into entry points to a worldwide network of information exchange and business transactions called the World Wide Web. However, the easy information access based on the success of the web has made it increasingly difficult to find, present, and maintain the information required by a wide variety of users. In response to this problem, many new research initiatives and commercial enterprises have been set up to enrich available information with machine-understandable semantics. This semantic web will provide intelligent access to heterogeneous, distributed information, enabling software products to mediate between user needs and the information sources available. Web Services tackle with an orthogonal limitation of the current web. It is mainly a collection of information but does not yet provide support in processing this information, i.e., in using the computer as a computational device. Recent efforts around UDDI, WSDL, and SOAP try to lift the web to a new level of service. Software programs can be accessed and executed via the web. However, all these service descriptions are based on semi-formal natural language descriptions. Therefore, the human programmer need be kept in the loop and scalability as well as economy of web services are limited. Bringing them to their full potential requires their combination with semantic web technology. It will provide mechanization in service identification, configuration, comparison, and combination. Semantic Web enabled Web Services have the potential to change our life in a much higher degree as the current web already did.

Dieter Fensel is an associated professor at the Vrije Universiteit Amsterdam in the area of business informatics. After studying mathematics, sociology and computer science in Berlin, he joined in 1989 the Institute AIFB at the University of Karlsruhe. His major subject was knowledge engineering and his PhD thesis in 1993 was about a formal specification language for knowledge-based systems. From 1994 until 1996 he visited the group of Bob Wielinga at the SWI Department in Amsterdam. During this time his main interest were problem-solving methods of knowledge-based systems. In 1996, he come back as a senior researcher at the Institute AIFB finalizing his Habilitation in 1998. Currently, his foccus is on the use of Ontologies to mediate access to heterogeneous knowledge sources and to apply them in knowledge management and electronic commerce.