Recent research and projects

Distributed Event-Based Systems

Many distributed systems use synchronous message-based communication.  Each request from a client is sent directly to a service provider, the timing of whose response to the client is time-related to the receipt of the request.  For example, a web browser sends a page request to a web server who immediately (or as soon as possible) seeks out the page and sends back the response.  However, some application models don't fit the synchronous communication pattern - instead, they fit an asynchronous communication pattern.  In this model, clients send requests, but the response back from service providers is not time-related to the request.  One particular instance of asynchronous communication is found in distributed event-based systems, in which clients register with a server network to receive events satisfying particular criteria and event providers publish events onto the network.  Whenever the network detects that an event satisfies a client's criteria, that event is sent on to the client.

My particular interest lies in distributed event-based systems built using content-based publish/subscribe networks, and in how composite events can be used to detect patterns of events within a network.  Currently, I am looking at how to order event on servers in a distributed environment without requiring global clock synchronization.

In 2005,  I completed an EPSRC-funded research project called "A Functional language and Architecture for Content-Based Publish/Subscribe Networks".  The aim of the project was to investigate and test the feasibility of a functional publish/subscribe subscription language that allowed specification of composite events in a distributed environment.  We implemented the language and developed a prototype pub/sub network using Java and JXTA called FEL.

As an extension of FEL, we also developed FWEB, which  used content-based publish/subscribe to allow hyperlinks to be coded in terms of required content rather than hard-coded URLs.  The web servers in FWEB then communicate to resolve where the links should be pointing to.

For details of FEL and FWEB, please see my publications.

Previous Research and Collaborations

• Semantics-Based Active Information Delivery. Combining Semantic Web technologies, user modeling and content-based publish/subscribe networks to create a semantic-based active information delivery system.  This is being done in collaboration with Trinity College Dublin and AIT, Greece.
• Implementing optimisation techniques for active (ECA) functional databases (with Prof. Alex Poulovassilis at Birkbeck College, London

I would also like to return to the subject of type-inference and program analysis (from my PhD thesis), but that's for another day.

Research Activities

·         Head of the Software Systems Engineering (SSE) Research Group in the Cavendish School of Computer Science at University of Westminster, and a member of the school research committee.

·         Co-organizer of the Workshops on Innovations in Web Infrastructure (IWI).  1^st workshop co-located with the 14^th World-Wide Web Conference (WWW), Japan, May 2005 (http://www.wmin.ac.uk/~courtes/iwi2005/).  2^nd IWI workshop, co-located with 15^th WWW Conference, Edinburgh May 2006 (http://www.wmin.ac.uk/~courtes/iwi2006/).

·         Programme committee member for  2^nd International Conference on E-Commerce and Telecommunications Networks (http://www.icete.org) 2005.

·         Programme committee member for the 5^th International Workshop on Distributed Event-Based Systems, 2-3 July 2006 (http://www.cs.waikato.ac.nz/~hinze/DEBS2006/)

·         Programme committee member for International Workshop on Reliability in Decentralized Distributed Systems (http://www.cs.rmit.edu.au/fedconf/index.html?page=rdds2006cfp) in 2006, 2007 and 2008.

·         Member of editorial board for Journal of Systems and Software (published by Elsevier)

I am a principal lecturer in the School of Electronics and Computer Science here at University of Westminster, but back in 1985, I graduated with a degree in Business. Fortunately, I went straight into my first job as a trainee COBOL programmer with the Civil Service. In 1989, I went to University College London to do an MSc in Computer Science with a thesis on Strictness Analysis of functional programming languages, and stayed on to do a PhD on the subject of type-based program analysis of the lambda calculus (which underlies all functional programming languages). After 1994, I did a couple of postdoctoral jobs before embarking on a short career as a freelance IT contractor. In 2000, I made my return to academia, with my lectureship at Westminster