User profiles for Michael Powell

Michael Powell

Atomic Layer Deposition Applications Engineer, Oxford Instruments
Verified email at ucl.ac.uk
Cited by 3589

A rapidly convergent descent method for minimization

R Fletcher, MJD Powell - The computer journal, 1963 - academic.oup.com
A powerful iterative descent method for finding a local minimum of a function of several
variables is described. A number of theorems are proved to show that it always converges and …

An efficient method for finding the minimum of a function of several variables without calculating derivatives

MJD Powell - The computer journal, 1964 - academic.oup.com
A simple variation of the well-known method of minimizing a function of several variables by
changing one parameter at a time is described. This variation is such that when the …

A fast algorithm for nonlinearly constrained optimization calculations

MJD Powell - Numerical Analysis: Proceedings of the Biennial …, 2006 - Springer
… of some of the convergence properties of our method is reported elsewhere (Powell, 1977). …
Our numerical results and the convergence theory in Powell (1977) show that a superlinear …

[BOOK][B] Approximation theory and methods

MJD Powell - 1981 - books.google.com
Most functions that occur in mathematics cannot be used directly in computer calculations.
Instead they are approximated by manageable functions such as polynomials and piecewise …

Direct search algorithms for optimization calculations

MJD Powell - Acta numerica, 1998 - cambridge.org
Many different procedures have been proposed for optimization calculations when first
derivatives are not available. Further, several researchers have contributed to the subject, …

Convergence properties of a class of minimization algorithms

MJD Powell - Nonlinear programming 2, 1975 - Elsevier
… d9, (4.8) 17 MJD POWELL which may be verified by integration … Because we have shown
that if 19 MJD POWELL k > kQ then … POWELL . to be no less than a constant positive multiple of …

Restart procedures for the conjugate gradient method

MJD Powell - Mathematical programming, 1977 - Springer
The conjugate gradient method is particularly useful for minimizing functions of very many
variables because it does not require the storage of any matrices. However the rate of …

Band alignment of rutile and anatase TiO2

…, AJ Logsdail, SM Woodley, CRA Catlow, MJ Powell… - Nature materials, 2013 - nature.com
The most widely used oxide for photocatalytic applications owing to its low cost and high
activity is TiO 2 . The discovery of the photolysis of water on the surface of TiO 2 in 1972 1 …

Radial basis functions for multivariable interpolation: a review

MJD Powell - Algorithms for approximation, 1987 - dl.acm.org
This paper presents a method for efficient Radial basis function (RBF) evaluation if
compactly supported radial basis functions (CSRBF) are used. Application of CSRBF leads …

[PDF][PDF] The BOBYQA algorithm for bound constrained optimization without derivatives

MJD Powell - Cambridge NA Report NA2009/06, University of …, 2009 - bison.ihep.su
BOBYQA is an iterative algorithm for finding a minimum of a function F (x), x∈ Rn, subject to
bounds a≤ x≤ b on the variables, F being specified by a “black box” that returns the value …