with application to fluid (2009)
K. A. Cliffe, A. Spence, Claverton Down, Bath Ba Ay, S. J. Tavener, K. A. Cliffe, ...
The numerical analysis of bifurcation problems
Can we do without GUIs? Gesture and speech interaction with a patient information system (2009)
Manasawee Kaenampornpan, Vassilis Kostakos, Andrew Warr, Dawn Woodgate, Bath Ba Ay
We have developed a gesture input system that provides a common interaction technique across mobile, wearable and ubiquitous computing devices of diverse form factors. In this paper, we combine our...
Departments of Psychology and Biological Sciences (2008)
Dylan Evans, Annerieke Heuvelink, Daniel Nettle, Biomimetics Group, Bath Ba Ay, Walton Hall
Are motivational biases adaptive? An agent-based model of human
Andrei Gabrielov, Nicolai Vorobjov, Bath Ba Ay, Of A. Gabrielov, N. Vorobjov
Abstract. Let X be a semialgebraic set in R n defined by a Boolean combination of atomic formulae of the kind h ∗ 0 where ∗∈{>, ≥, =}, deg(h) <d, and the number of distinct polynomials...
Richard Vidgen, Bath Ba Ay, Sabine Madsen
Socio-technical design is an established technique in the information system development repertoire with a strong provenance in the Mumford’s work on ETHICS and the participatory design tradition...
J. P. Collomosse, Bath Ba Ay, P. M. Hall, Bath Ba Ay
We present a new non-photorealistic rendering (NPR) algorithm for rendering photographs in an impasto painterly style. We observe that most existing image-based NPR algorithms operate in a spatially...
Abstract: In the complexity of modern, computerised systems, the current system state can come as an unpleasant shock to even an experienced user. The dominant thinking in this field [Palmer, 1995,...
Projection pursuit is an exploratory data-analytic method in multivariate (MV) analysis. It is similar to the well-known principal components analysis (PCA) in that it can be used to nd interesting...
Branching Humphreys And, Bath Ba Ay
The growth of a solid turnour is dependent on an adequate supply of nutrients. A turnout can establish a blood supply by inducing neighbouring blood vessels to sprout and grow towards it, a process...
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...
Meagre functions and asymptotic behaviour of dynamical systems, Nonlinear Analysis: Theory (2007)
W. Desch, H. Logemann, E. P. Ryan, Bath Ba Ay, E. D. Sontag
Abstract. A measurable function x: J ae R! X (X a metric space) is said to be C-meagre if C ae X is non-empty and, for every closed set K ae X with K " C =;, x \Gamma1 (K) has finite...
School of Mathematical Sciences, (2007)
Fengshan Bai, A. R. Champneys, Bath Ba Ay
An extension of an existing truncated boundary-value method for the numerical continuation of connecting orbits is proposed to deal with homoclinic orbits to a saddle-node equilibrium. In contrast to...
A mixed boundary value problem is posed for the Lam'e system in an elastic multi--structure which consists of a union of a three--dimensional domain and thin cylinders. A normalized thickness of...
There are embeddings of complex abelian surfaces in P 4 (2007)
but it was shown by Van de Ven in [17] that no abelian d-fold can be embedded in P
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...
Department of Mathematical Sciences, University of Bath, (2007)
Physical modelling of musical instruments is one possible approach to digital sound synthesis techniques. By the term physical modelling, we refer to the simulation of sound production mechanism of a...
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...
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...
Travelling-Wave Solutions for Reaction-Diffusion-Convection Systems (2007)
We prove the existence of travelling-wave solutions of the parabolic system @u @t = A @ 2 u @x 2 + G(u; @u @x ) @u @x + f(u); where the reaction term f is of `bistable' type and the convection...
Dynamic Weight Functions for a Moving Crack II. Shear Loading (2007)
A. B. Movchan, J. R. Willis, Bath Ba Ay
Dynamic weight functions are constructed for general time--dependent shear loading of a plane semi--infinite crack propagating with constant speed in an infinite isotropic elastic body. The use of...
J.F. Toland, D. Williams, Bath Ba Ay
The Schur sufficiency condition for boundedness of any integral operator with non-negative kernel between L 2 -spaces is deduced from an observation, Proposition 1.2, about the central role played by...
Optimal L p estimates for the solutions of elliptic equations in bounded domains (2007)
: Linear second-order elliptic Dirichlet problems are considered in a bounded domain\Omega ae R N . Isoperimetric inequalities are used to obtain sharp estimates of the solution operator from L p to...
this paper we give complete proofs of the main results about the Stokeswave problem starting with its basic formulation as a free boundary problem for a harmonic function in an unknown domain in the...
Remarks on the Vol'pert theory of travelling-wave solutions for parabolic systems (2007)
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)
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...
Entropy in Multivariate Analysis: Projection Pursuit (2007)
Projection pursuit is an exploratory data-analytic method in multivariate (MV) analysis. It is similar to the well-known principal components analysis (PCA) in that it can be used to find interesting...
Adaptive Fractal Video J.A.Nicholls and D.M.Monro (2007)
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,...
Galerkin Approximations to Static and Dynamic Localization Problems (2007)
M. K. Wadee, Y. Higuchi, G. W. Hunt, Bath Ba Ay
A new Galerkin-type procedure is established which, unlike the classical approach, does not rely on the final shape being composed of linearly independent modes. The procedure is applied to the...
and Biological Sciences (2007)
Dylan Evans, Bath Ba Ay, Annerieke Heuvelink, Daniel Nettle
The evolution of optimism:
School of Mathematical Sciences, (2007)
Christopher Jennison, Bath Ba Ay, Bruce W. Turnbull
In this paper we survey existing results concerning the joint distribution of the sequence of estimates of the parameter vector when a model is fitted to accumulating data and we provide a unified...
for Computer Algebra www.orcca.on.ca (2007)
Robert M. Corless, David J. Jerey, Stephen M. Watt, Russell Bradford, James H. Davenport, Bath Ba Ay
about the elementary functions of complex analysis
Hartmut Logemann, Bath Ba Ay, Richard Rebarber, Stuart Townley
Abstract: Suppose that a static state feedback stabilizes a continuous-time linear innite-dimensional control system. We consider the following question: if we construct a sampled-data controller by...
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...
Christopher Jennison, Bath Ba Ay, Bruce W. Turnbull
We derive the joint distribution of the sequence of estimates of the parameter vector ` in a normal general linear model when data accumulate over a series of analyses. This sequence of estimates has...
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...
Passification Of Electrohydraulic Valves (2007)
Using Bond Graphs, Church St. Se, Bath Ba Ay
In many applications that require physical interaction with humans or other physical environments, passivity is a useful property to have in order to improve safety and ease of use. Many hydraulic...
Atomic Diffusion from a Material Surface into a Grain Boundary (2007)
Y. A. Antipov, H. Gao, Bath Ba Ay
A model problem of stress induced atomic diffusion from the surface of a material into a semi-infinite grain boundary orthogonal to the surface is analysed. The governing equation is shown...
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.
R. Granger, A. J. Holt, N. P. Smart, F. Vercauteren, Bath Ba Ay
Abstract. In this paper we investigate the efficiency of the function field sieve to compute discrete logarithms in the finite fields F3n. Motivated by attacks on identity based encryption systems...
Why study multifractal spectra? (2007)
We show by three simple examples how multifractal spectra can enrich our understanding of stochastic processes. The first example concerns the problem of describing the speed of fragmentation in a...
On the proof complexity of deep inference (2007)
Paola Bruscoli, Alessio Guglielmi, Bath Ba Ay
cs.bath.ac.uk/pb / and alessio.guglielmi.name/res
A system of interaction and structure IV: The exponentials (2007)
Alessio Guglielmi, Bath Ba Ay, Lutz Straßburger, Inria Futurs Parsifal
Abstract We study some normalisation properties of the deep-inference proof system NEL, which can be seen both as 1) an extension of multiplicative exponential linear logic (MELL) by a certain...
A unifying class of Skorokhod embeddings: connecting (2006)
York Y Dd, D. G. Hobson, Bath Ba Ay
In this paper we consider the Skorokhod embedding problem in Brownian motion.
A unifying class of Skorokhod embeddings: connecting (2005)
York Y Dd, D. G. Hobson, Bath Ba Ay
In this paper we consider the Skorokhod embedding problem in Brownian motion.
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 Integrated Context Model: Bringing Activity to Context (2004)
Manasawee Kaenampornpan, Eamonn O'Neill, Bath Ba Ay
This paper presents ongoing research on context modelling. A review of past research in context awareness shows that researchers have defined and classified context differently. This leads to...
Modelling Context: An Activity Theory Approach (2004)
Manasawee Kaenampornpan And, Bath Ba Ay
In this paper, we review different context classification systems that have been used to define elements of context. Although existing classification systems cover various types of context, in the...
Skorokhod embeddings, minimality and non-centred (2004)
York Y Dd, Target Distributions Cox, D. G. Hobson, Bath Ba Ay
In this paper we consider the Skorokhod embedding problem for target distributions with non-zero mean. In the zero-mean case, uniform integrability provides a natural restriction on the class of...
Assessing the Quality of Auction Web Sites (2001)
Stuart Barnes, Richard Vidgen, Bath Ba Ay
WebQual is an instrument for assessing the quality of Internet sites from the perspective of the customer. Earlier versions of WebQual focused on information and interaction quality. This paper...
Louise Knight, Christine Harland, Helen Walker, Roxanne Sutton, Bath Ba Ay
Purchasing and Supply Agency (England) and CRiSPS. The Agency’s support is gratefully acknowledged. 1 Competence Requirements For Managing Supply In Interorganizational Networks There is evidence...
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.
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...
A small openmath type system (1999)
James H. Davenport, Bath Ba Ay
This paper describes the "light-weight " Small Type System of OpenMath. It is based on various discussion with the OpenMath Consortium, and notably with the NAG team. Section 7...
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...
Exact Solution of Integro-Differential Equations of Diffusion Along a Grain Boundary (1999)
Y. A. Antipov, H. Gao, Bath Ba Ay
We analyze model problems of stress induced atomic diffusion from a point source or the surface of a material into an infinite or semi-infinite grain boundary, respectively. The problems are...
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...
Massively Parallel Methods for Semiconductor Device Modelling (1996)
R. K. Coomer, I.G. Graham, Bath Ba Ay
In this paper we describe, analyse and implement a parallel iterative method for the solution of the steady-state drift diffusion equations governing the behaviour of a semiconductor device in two...
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...
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...
Victor A. Galaktionov, Bath Ba Ay, Josephus Hulshof, Juan L. Vazquez
We consider a free-boundary problem for the heat equation which arises in the description of premixed equi-diffusional flames in the limit of high activation energy. It consists of the heat equation...
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....
Analysis of a Three-Dimensional Point Pattern with Replication (1991)
A. J. Baddeley, R. A. Moyeed, C. V. Howard, A. Boyde, Claverton Down, Bath Ba Ay
This paper has been submitted for publication. Introduction
By Victor, Victor A. Galaktionov, Bath Ba Ay, Josephus Hulshof, Juan L. Vazquez
We consider a free-boundary problem for the heat equation which arises in the description of premixed equi-diffusional flames in the limit of high activation energy. It consists of the heat equation...
Estimates on the Green's function of second-order elliptic operators in R^N
: Sharp upper and lower pointwise bounds are obtained for the Green's function of the equation (L + )u j \Gamma\Deltau + a(x):ru + u = f; x 2 R N ; for ? 0. Initially in a Cartesian frame it is...
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...
Estimates on the Heat Kernel of Parabolic Equations With Advection
: The paper considers heat kernels of second--order parabolic equations in R N , with constant uniform diffusion and advective coefficients bounded in the maximum norm. Two critical cases,...
Function Field Sieve in Characteristic Three
Granger Holt Page, R. Granger, A. J. Holt, N. P. Smart, F. Vercauteren, Bath Ba Ay
In this paper weinvestigate the e#ciency of the function #eld sieve to compute discrete logarithms in the #nite #elds F3 n . Motivated by attacks on identity based encryption systems using...
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...