Claverton Down

Publication List Details

Period

1991 - 2009

Number

43

Co-Authors

676 SME TRANSFORMATION: MODELLING PROGRESSIONS ABSTRACT (2008)

Margi Levy, Philip Powell, Coventry Cv Al, Claverton Down, Bath Ba

Small firms (SMEs) are encouraged to embrace e-business. However, the mechanisms by which such business transformation occurs is not understood. IS transformation models suggest a single path,...

Mathematical Sciences (2008)

Coldharbour Lane, Mohammed Odeh, Richard Kamm, Claverton Down

This paper discusses links that may be made between process models and UML software specification techniques. The approach taken is to develop a set of use cases which would be capable of providing...

IDEOLOGY OR PRAGMATISM? OPEN STANDARDS AND CULTURAL HERITAGE WEB SITES (2008)

Claverton Down

The importance of open standards for providing access to digital resources is widely acknowledged. Bodies such as the W3C are developing the open standards needed to provide universal access to...

Stability Results of Popov-Type for Infinite-Dimensional Systems with Applications to Integral Control (2008)

R. F. Curtain, H. Logemann, Claverton Down, O. Staffans

We derive absolute stability results of Popov-type for in nite-dimensional systems in an input-output setting. Our results apply to feedback systems where the linear part is the series...

Moving mesh generation using the Parabolic Monge-Ampère equation (2008)

C. J. Budd, J. F. Williams, Claverton Down, Ba Ay

This article considers a new method for generating a moving mesh which is suitable for the numerical solution of partial differential equations in several spatial dimensions. The mesh is obtained by...

University of Bath, (2007)

Hartmut Logemann, Claverton Down, Bath Ba Ay, Richard Rebarber

Abstract: In this paper we consider a large class of partial differential equations (PDEs) with distributed control and with a time-delay in the feedback loop. We analyze the relationship between the...

Regularity of Stokes Waves in Hardy Spaces and in Spaces of Distributions (2007)

J. F. Toland, Claverton Down, Bath Ba Ay

This paper deals with some functional-analytic questions which arise when the Stokes-wave problem, for the free boundary of a steady irrotational water wave, is formulated as a quadratic equation for...

A Library for Parallel Modular Arithmetic (2007)

David Power, Russell Bradford, Claverton Down, England Ba Ay

. This paper describes a library of platform independent functions for performing modular arithmetic on a range of parallel hardware. It is based around an approximate Chinese remainder...

Destabilizing Effects of Small Time-Delays on Feedback Controlled Descriptor Systems (2007)

Hartmut Logemann, Claverton Down, Bath Ba Ay

: In the last 15 years the problems of stabilizability and stabilization of descriptor systems have received considerable attention. In this paper it will be shown that if the open-loop system...

Absolute Stability Results for Well-Posed Infinite-Dimensional Systems with Applications to Low-Gain Integral Control (2007)

H. Logemann, R.F. Curtain, Claverton Down

: We derive absolute stability results for well-posed innite-dimensional systems which, in a sense, extend the well-known circle criterion to the case that the underlying linear system is the series...

NMDA Receptors, Wind-Up and the Gate Control Theory of Pain - a Mathematical Model (2007)

Britton Chaplain Suzanne, N. F. Britton, Suzanne M. Skevington, Claverton Down, Bath Ba Ay

We present a mathematical model which is an extension of that of Britton and Skevington (1989) for the gate control theory of pain (Melzack and Wall, 1965, 1982). The variables of the model are the...

Adaptive Lambda-Tracking for a Class of Infinite-Dimensional Systems (2007)

Achim Ilchmann, Exeter Ex Qe, Hartmut Logemann, Claverton Down, Bath Ba Ay

: For a class of high-gain stabilizable multivariable linear infinite-dimensional systems we present an adaptive control law which achieves approximate asymptotic tracking in the sense that the...

Remarks on the Vol'pert theory of travelling-wave solutions for parabolic systems (2007)

Claverton Down, Bath Ba Ay

Vol'pert and Vol'pert have shown that the parabolic system of n equations, @u @t = A @ 2 u @x 2 + f(u) has monotone travelling-wave solutions connecting two equilibria, S and T say, under...

Bifurcation from the essential spectrum for almost-periodic perturbations of Hill's equation (2007)

Claverton Down, Bath Ba Ay

We show that the inmum of the essential spectrum of the linearisation of the equation  u(x) + V (x)u(x) r(x)ju(x)j p 1 u(x) = u(x) (1) is a bifurcation point for (1). Here the potential V is...

Algebraic Construction of Normalized Coprime Factors for Delay Systems (2007)

J. R. Partington, G.K. Sankaran, Claverton Down, Bath Ba Ay

We introduce an algebraic approach to the problem of constructing explicit normalized coprime factorizations for retarded delay systems. A parametrization is given of all the possible factorizations...

Adaptive Fractal Video J.A.Nicholls and D.M.Monro (2007)

Claverton Down, Bath Ba Ay

We report real time fractal coding of 160 by 128 colour images using a standard 33 MHz 486i computer. The system utilizes the Bath Fractal Transform (BFT)[1], applied to variable size square blocks,...

Transient loading of a rapidly-advancing crack in a viscoelastic medium (2007)

Y. A. Antipov, J. R. Willis, Claverton Down, Bath Ba Ay

problem, stress-intensity factor. The problem that is studied concerns a semi-innite crack in an innite viscoelastic medium, propagating at uniform speed but subject to time-dependent loading. A...

On the Integro-Differential Equation Associated with Diffusive Crack Growth Theory (2007)

Y. A. Antipov, H. Gao, Claverton Down, Bath Ba Ay

At high temperatures, polycrystalline materials often suffer creep fracture under prolonged loading conditions. Microstructural examinations reveal that nucleation, propagation and linkage of...

Absolute Stability Results in Infinite Dimensions (2007)

R. F. Curtain, H. Logemann, Claverton Down, O. Staffans

We derive absolute stability results of Popov and circle-criterion type for in nite-dimensional systems in an input-output setting. Our results apply to feedback systems where the linear part is the...

Maximising the Probability of a Perfect Hedge (2007)

Using An Imperfectly, David Hobson, Jeremy Penn, Claverton Down, Bath Ba Ay

Consider a trading wealth generated from investing in a geometricBrownian asset and consider a geometric-Brownian contingent claim.

IDEOLOGY OR PRAGMATISM? OPEN STANDARDS AND CULTURAL HERITAGE WEB SITES (2007)

Claverton Down

The importance of open standards for providing access to digital resources is widely acknowledged. Bodies such as the W3C are developing the open standards needed to provide universal access to...

2007.02 Richard Fairchild Audit Tenure, Report Qualification, and Fraud (2007)

Johan Lindeque, Mark Lund, Steven Mcguire, Claverton Down, Ba Ay, Robert Heath, ...

This working paper is produced for discussion purposes only. The papers are expected to be published in due course, in revised form and should not be quoted without the author’s permission.

2007.02 Richard Fairchild Audit Tenure, Report Qualification, and Fraud (2007)

Robert Heath, Claverton Down, Ba Ay, Robert Heath, Stephan C, Henneberg Daniel, ...

This working paper is produced for discussion purposes only. The papers are expected to be published in due course, in revised form and should not be quoted without the author’s permission.

Hierarchy-of-Processing Model (2007)

Patchareeporn Pluempavarn, Niki Panteli, Claverton Down, Ba Ay, Robert Heath, Stephan C, ...

This working paper is produced for discussion purposes only. The papers are expected to be published in due course, in revised form and should not be quoted without the author’s permission.

E-I.02 9:00-Invited- PHASE AND ORIENTATION CONTROL OF MESOPOROUS SILICA THIN FILM VIA (2005)

Hugh W. Hillhouse, Karen J Edler, Cristina Fern, Claverton Down, ...

SYMPOSIUM E Synthesis, characterization and applications of mesostructured thin layers

Under consideration for publication in Math. Struct. in Comp. Science The Semantics of BI and Resource Tableaux (2005)

D. Galmiche, D. Méry, D. Pym, Loria Umr, Poincaré Nancy, ...

The logic of bunched implications, BI, provides a logical analysis of a basic notion of resource rich enough, for example, to form the logical basis for “pointer logic ” and “separation logic...

An Investigation of Techniques for Improving the Performance of a Pittsburgh Approach Learning Classifier System (2004)

Anne Stacey, Claverton Down, Anne Stacey

This dissertation may be made available for consultation within the University Library and may be photocopied or lent to other libraries for the purposes of consultation....

Limits in Long Path Learning with XCS (2003)

Alwyn Barry, Claverton Down

Abstract. The development of the XCS Learning Classifier System [26] has produced a stable implementation, able to consistently identify the accurate and optimally general population of classifiers...

Bridging the gap between business models and system models (2003)

Mohammed Odeh, Richard Kamm, Claverton Down

This paper discusses links that may be made between process models and UML software specification techniques, working from an argument that the whole complexity of organisational activity cannot be...

Algebraic Construction of Normalized Coprime Factors for Delay Systems (2001)

J. R. Partington, G. K. Sankaran, Claverton Down, Bath Ba Ay

We introduce an algebraic approach to the problem of constructing explicit normalized coprime factorizations for retarded delay systems.

Implementation and performance issues in the Bayesian and likelihood fitting of multilevel models (2000)

William J. Browne, David Draper, Claverton Down, Bath Ba Ay

We use simulation studies (a) to compare Bayesian and likelihood fitting methods, in terms of validity of conclusions, in two-level random-slopes regression (RSR) models, and (b) to compare several...

Frictional Contact of a Fibre and an Elastic Solid (1999)

Y. A. Antipov, N.V. Movchan, Claverton Down, Bath Ba Ay

Motivated by an asymptotic model of pullout test for a frictional bre in a solid, we consider a boundary layer model problem for an elastic space containing an innite cylindrical bre with a...

Robust Hedging of Barrier Options (1998)

Haydyn Brown, David Hobson, Claverton Down, Bath Ba Ay

This article considers the pricing and hedging of barrier options in a market in which call options are liquidly traded and can be used as hedging instruments. This use of call options means that...

The Maximum Maximum of a Martingale Constrained by an Intermediate Law. (1998)

Haydyn Brown, David Hobson, Claverton Down, Bath Ba Ay

Let (M t ) be any martingale with M 0 0, an intermediate law M 1 1 , and terminal law M 2 2 , and let M 2 sup 0t2 M t . In this paper we prove that there exists an upper bound, with respect to...

Implicitly restarted Arnoldi with purification for the shift-invert transformation (1995)

Karl Meerbergen, Alastair Spence, Claverton Down, Bath Ba Ay

The need to determine a few eigenvalues of a large sparse generalised eigenvalue problem Ax = Bx with semi-positive definite B arises in many physical situations, for example, in a stability analysis...

The Effect of Small Time-Delays on the Stability of Feedback Systems Described by Partial Differential Equations (1995)

Hartmut Logemann, Claverton Down, Bath Ba Ay, Richard Rebarber

: It has been observed that for many stable feedback systems, the introduction of arbitrarily small time delays into the loop causes instability. In this paper we present a systematic treatment of...

Bifurcation and coalescence of a plethora of homoclinic orbits for a Hamiltonian system (1994)

B. Buffoni, A. R. Champneys, J. F. Toland, Claverton Down, Ba Ay, U \gamma U

This is a further study of the set of homoclinic solutions (i.e. non-zero solutions asymptotic to 0 as jxj !1) of the reversible Hamiltonian system u iv + Pu 00 + u \Gamma u 2 = 0: () The present...

Real Time Fractal Video For Personal Communications (1994)

Donald Monro, Jeremy A Nicholls, Claverton Down, Ba Ay

INTRODUCTION Our aim is to produce a low bandwidth video communication system using fractal compression. The bilinear BFT 1 enables us to perform fast fractal coding with reasonable fidelity. It...

Upper Semicontinuity of Attractors for Linear Multistep Methods (1993)

A.T. Hill, Claverton Down, Bath Ba Ay, E. Süli

This paper sets out a theoretical framework for approximating the attractor A of a semigroup S(t) defined on a Banach space X by a q--step semi--discretization in time with constant step--length k....

Mathematical Models for Tumour Angiogenesis: Numerical Simulations and Nonlinear Wave Solutions

H.M. Byrne, Claverton Down, Bath Ba Ay

To ensure its sustained growth, a tumour may secrete chemical compounds which cause neighbouring capillaries to form sprouts which then migrate towards it, furnishing the tumour with an increased...

Mathematical Models for Tumour Angiogenesis: Numerical Simulations and Nonlinear Wave Solutions

Byrne And Chaplain, Claverton Down, Bath Ba Ay

To ensure its sustained growth, a tumour may secrete chemical compounds which cause neighbouring capillaries to form sprouts which then migrate towards it, furnishing the tumour with an increased...