Navigation

Research

This page gives details of my research projects in the area of Computing. If you would like more information about any of the projects including questions about research publications or presentations, please contact me.

Doctoral Research: Hybrid Algorithms for Distributed Constraint Satisfaction.

Constraint Satisfaction Problems are solved by algorithms assigning values (from a domain) to variables in the problem so that all constraints are satisfied. In Distributed Constraint Satisfaction Problems, variables are represented by agents who have only a partial understanding of the problem (their understanding is limited to the variables they represent and the constraints that those variables are involved in). Distributed problems are important when information cannot be shared either because there is too much information or because of privacy concerns. Existing algorithms for Distributed Constraint Satisfaction can be categorised as backtracking and local search algorithms. The former, whilst able to guarantee completeness, are often too slow for practical use whilst the later are often able to converge to a solution quicker but may not solve all problems (i.e. they are incomplete). In my doctoral research, I investigated and developed hybrid algorithms for Distributed Constraint Satisfaction, combining the convergence abilities of local search with the completeness of backtracking. This has led to the development of new algorithms for Distributed Constraint Satisfaction including PenDHyb, Multi-Hyb und Multi-HDCS. My thesis can be downloaded here. Dates: October 2006 to March 2010 (PhD awarded). Supervisor(s): Dr. Ines Arana, Dr. Hatem Ahriz and Dr. Kit-Ying Hui.

Publications:

Presentations:

Software:


Project Title: "SIDCOT: A Smart Interface for Constraint Programming".

Facilitating the input of a model which ensures efficiency during the search for a solution is no easy task. Additionally, presenting the solution to the user so that they can understand it is also not trivial. Therefore, I designed SIDCOT as my Honours Individual Project for my Computing for Business and E-Commerce honours degree. The software provides a wizard-style interface which guides the user from problem modelling (as a Constraint Satisfaction Problem) through problem solving to the display of the solution with minimal constraint programming knowledge. The project exceeded all aims and objectives and, consequently, was awarded the highest grade. (The software was updated and extended during my doctoral research to use the new algorithms I developed during my PhD.) Dates: September 2005 to April 2006 (part-time). Supervisor(s): Dr. Ines Arana

Presentations:


Project Title: "A Comparison of Two Distributed Constraint Satisfaction Algorithms".

Currently there is no one algorithm which is capable of solving all Distributed Constraint Satisfaction problems. However, a number of algorithms do exist which are suited to different problems. This project compared the Distributed Breakout Algorithm with the Distributed Stochastic Algorithm on randomly-generated problems and scheduling problems. Our tentative conclusions suggested that the Distributed Breakout Algorithm was more suited to randomly-generated problems whilst the Distributed Stochastic Algorithm performed better on scheduling problems. A prize was awarded for the research undertaken during this project. In addition to my research, I developed an experimental workbench written in Java to compare Distributed Constraint Satisfaction algorithms. This experimental workbench (SEICOSSA – A Smart Experimental Interface for Constraints) was also used and further developed during my doctoral research.Dates: May to September 2005. Supervisor(s): Dr. Ines Arana and Dr. Hatem Ahriz.

Presentations:

Software:


Project Title: "On The Effectiveness of Relevance Profiling".

How effective is relevance profiling in retrieving relevant pages of a book as defined by the book’s own index? This project sought to measure this effectiveness through an investigation of a number of weighting functions on the within-document retrieval tool, ProfileSkim. The project was fully funded by the Robert Gordon University. Conclusions from the project were presented at the Ninth Australasian Document Computing Symposium. Dates: June to September 2004. Supervisor(s): Professor David J Harper.

Presentations:

Publications:

Navigation