Article
Comparison of Alternating Variable Search and Simplex Methods of Optimisation for Inductively Coupled Plasma Optical Emission and Atomic Fluorescence Spectrometry
Journal of Analytical Atomic Spectrometry
(1989)
Abstract
The performance of several cyclic alternating variable search (AVS) optimisation methods are compared with
two simplex methods with respect to the number of changes of variable required to search a model two-factor
response space. The roles of the initial step size and of the variable step size are discussed, and the
information produced concerning the shape of the factor space is evaluated. An AVS method which starts
with a fixed step size and then changes to a variable step size on second and subsequent cycles is compared
with a variable step size simplex for the optimisation of an inductively coupled plasma optical emission
spectrometer and of the atomiser, source inductively coupled plasmas in atomic fluorescence spectrometry
(the ASIA system). The order in which the variables are taken in the AVS method does not affect the value of
the optimum eventually found. Both methods perform satisfactorily for the optical emission work, although
the AVS method provides information about the shape of the factor space which is easier to interpret than in
the simplex method. However, the simplex method was not always able to satisfy the conditions for
termination in the case of the atomic fluorescence studies and was much slower to implement than the AVS
method as the latter used direct visual feedback from the output of the lock-in amplifier as a measure of the
figure of merit (total fluorescence signal).
Keywords
- Inductively coupled plasma optical emission spectrometry,
- inductively coupled plasma atomic fluorescence spectrometry,
- atomiser,
- simplex method,
- alternating variable search optimisation,
- source inductively coupled plasmas in atomic fluorescence spectrometry
Disciplines
Publication Date
1989
Citation Information
Julian Tyson, Stanley Greenfield, Mahmood S Salman and Maryanne Thomsen. "Comparison of Alternating Variable Search and Simplex Methods of Optimisation for Inductively Coupled Plasma Optical Emission and Atomic Fluorescence Spectrometry" Journal of Analytical Atomic Spectrometry Vol. 4 (1989) p. 55 Available at: http://works.bepress.com/julian_tyson/31/