Alex Ferguson - Academia.edu (original) (raw)

Papers by Alex Ferguson

In this note, we report on an ESPRIT-funded project in which we are integrating the Galileo6 cons... more In this note, we report on an ESPRIT-funded project in which we are integrating the Galileo6 constraint language with an electronics design CAD package called Visula. We describe some aspects of the integration and show the functionality of the system, and conclude by discussing our findings.

Proceedings of ICTAI, Nov 15, 2004

Constraint satisfaction is becoming the paradigm of choice for solving many real-world problems. ... more Constraint satisfaction is becoming the paradigm of choice for solving many real-world problems. To date, most approaches to constraint satisfaction have focused on solving a problem using some form of backtrack search. Furthermore, the typical view is that a constraint satisfaction problem will be solved only once. However, in many real-world contexts, problems are solved repeatedly over time. Also such problems often exhibit some structure. This motivates the application of some form of learning to improve the performance of search from previously discovered solutions. In this paper we present an approach that uses knowledge about known solutions to a problem to improve search. The approach we present is based on a combination of decision tree learning and constraint satisfaction. We demonstrate that significant improvements, almost an order-of-magnitude, in search effort can be achieved using this hybrid approach over traditional search. We also show that the space complexity using this approach is almost negligible. This work is of interest in domains such as product configuration, and interactive constraint solving in general where the system takes the initiative by asking questions.

Principles and Practice of Constraint Programming-CP 2006, 2006

Proc. IJCAI-05 Configuration WS, Jul 30, 2005

In this paper we present an approach to using decision tree learning as a basis for improving sea... more In this paper we present an approach to using decision tree learning as a basis for improving search performance for real-world constraint satisfaction problems. The problem used to evaluate the approach is a large real-world configuration benchmark from the automotive industry.

Proc. of IEEE ECOC, Sep 21, 2008

Wavelength route correlation is considered for optimal monitor placement in transparent networks.... more Wavelength route correlation is considered for optimal monitor placement in transparent networks. The associated reduction in monitoring requirement is studied as a function of repair cost and traffic loading.

Optical Fiber …, Feb 24, 2008

Linear programming techniques are applied to the optimization of optical monitor placement by min... more Linear programming techniques are applied to the optimization of optical monitor placement by minimizing the worst case transparent path length in optical networks, which we study over different network topologies and traffic patterns.

Proceedings of the 4th International Conference on Concurrent Enterprising, University of Nottingham, Oct 1, 1997

Increasingly, it is being realised that success in manufacturing requires integration between the... more Increasingly, it is being realised that success in manufacturing requires integration between the various phases of the product life cycle. One of the key aspects of this integration is that, during the design of an artifact, due consideration should be given to facilitating the down-stream phases of the life-cycle. This is frequently known as "Design for X" (or DFX), where the X ranges over such issues as manufacturability, servicability and so on.

In Proc. of Int. Joint. Conf. on Artificial Intelligence (IJCAI, Jan 6, 2007

The Quantified Constraint Satisfaction Problem (QCSP) is a generalisation of the classical CSP in... more The Quantified Constraint Satisfaction Problem (QCSP) is a generalisation of the classical CSP in which some of variables can be universally quantified. In this paper, we extend two well-known concepts in classical constraint satisfaction to the quantified case: problem relaxation and explanation of inconsistency. We show that the generality of the QCSP allows for a number of different forms of relaxation not available in classical CSP. We further present an algorithm for computing a generalisation of conflict-based explanations of inconsistency for the QCSP.

Availability, Reliability and Security, 2007

Whether a particular computing installation meets its security goals depends on whether the admin... more Whether a particular computing installation meets its security goals depends on whether the administrators can create a policy that expresses these goals-security in practice requires effective policy engineering. We have found that the reigning SELinux model fares poorly in this regard, partly because typical isolation goals are not directly stated but instead are properties derivable from the type definitions by complicated analysis tools. Instead, we are experimenting with a security-policy approach based on copy-on-write "pastures", in which the sharing of resources between pastures is the fundamental security policy primitive. We argue that it has a number of properties that are better from the usability point of view. We implemented this approach as a patch for the 2.6 Linux kernel.