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Deformable models of elastic structures have been proposed for use in image analysis. Previous work has used a variational approach, based on the Euler-Lagrange theory. In this paper an alternative mathematical treatment is introduced, based on a direct minimisation of the underlying energy integral using the Finite Element Method. The method is outlined(More)
We consider the imposition of Dirichlet boundary conditions in the finite element modelling of moving boundary problems in one and two dimensions for which the total mass is prescribed. A modification of the standard linear finite element test space allows the boundary conditions to be imposed strongly whilst simultaneously conserving a discrete mass. The(More)
A new family of mathematical functions to fit longitudinal growth data is described. All members derive from the differential equation dh/dt = s(t). (h1-h) where h1 is adult size and s(t) is a function of time. The form of s(t) is given by one of many functions, all solutions of differential equations, thus generating a family of different models. Three(More)
This paper discusses the problem of constructing a locally optimal mesh for the best L 2 approximation of a given function by discontinuous piecewise polynomials. In the one-dimensional case, it is shown that, under certain assumptions on the approximated function, Baines' algorithm [M. for piecewise linear or piece-wise constant polynomials produces a mesh(More)
A scale-invariant moving finite element method is proposed for the adaptive solution of nonlinear partial differential equations. The mesh movement is based on a finite element discretisation of a scale-invariant conservation principle incorporating a monitor function, while the time discretisation of the resulting system of ordinary differential equations(More)
Patients who are dying of cancer usually give up eating and then stop drinking. This raises ethical dilemmas about providing nutritional support and fluid replacement. The decision-making process should be based on a knowledge of the risks and benefits of giving or withholding treatments. There is no clear evidence that increased nutritional support or(More)
A distributed Lagrangian moving-mesh finite element method is applied to problems involving changes of phase. The algorithm uses a distributed conservation principle to determine nodal mesh velocities, which are then used to move the nodes. The nodal values are obtained from an ALE (Arbitrary Lagrangian-Eulerian) equation, which represents a gener-alisation(More)
A numerical study of fluid mechanics and heat transfer in a scraped surface heat exchanger with non-Newtonian power law fluids is undertaken. Numerical results are generated for 2D steady-state conditions using finite element methods. The effect of blade design and material properties, and especially the independent effects of shear thinning and heat(More)
A clinical and pathological study was made of 40 patients with intestinal obstruction due to far-advanced abdominal and/or pelvic malignant disease. Surgical intervention was feasible in only 2 cases. The remaining 38 patients were managed medically without intravenous fluids and nasogastric suction. Obstructive symptoms such as intestinal colic, vomiting,(More)