EPI Update, March 16, 2007

Weekly newsletter for Center For Acute Disease Epidemiology of Iowa Department of Public Health.

Iowa Developments, Volume 16, Number 3

Business news from the Iowa Department of Economic Development

Experimental design on the simplex

Optimum experimental designs depend on the design criterion, the model andthe design region. The talk will consider the design of experiments for regressionmodels in which there is a single response with the explanatory variables lying ina simplex. One example is experiments on various compositions of glass such asthose considered by Martin, Bursnall, and Stillman (2001).Because of the highly symmetric nature of the simplex, the class of models thatare of interest, typically Scheff´e polynomials (Scheff´e 1958) are rather differentfrom those of standard regression analysis. The optimum designs are also ratherdifferent, inheriting a high degree of symmetry from the models.In the talk I will hope to discuss a variety of modes for such experiments. ThenI will discuss constrained mixture experiments, when not all the simplex is availablefor experimentation. Other important aspects include mixture experimentswith extra non-mixture factors and the blocking of mixture experiments.Much of the material is in Chapter 16 of Atkinson, Donev, and Tobias (2007).If time and my research allows, I would hope to finish with a few comments ondesign when the responses, rather than the explanatory variables, lie in a simplex.ReferencesAtkinson, A. C., A. N. Donev, and R. D. Tobias (2007). Optimum ExperimentalDesigns, with SAS. Oxford: Oxford University Press.Martin, R. J., M. C. Bursnall, and E. C. Stillman (2001). Further results onoptimal and efficient designs for constrained mixture experiments. In A. C.Atkinson, B. Bogacka, and A. Zhigljavsky (Eds.), Optimal Design 2000,pp. 225–239. Dordrecht: Kluwer.Scheff´e, H. (1958). Experiments with mixtures. Journal of the Royal StatisticalSociety, Ser. B 20, 344–360.1

Puolustusministeri Arvo Pentti 16/8 1965

Kirje

Siofokissa, pienessä kylpypaikassa Balaton-järven etelärannalla. Lauantaina 16/6 -28

Kirje 16.6.1928

Iowa Developments, July 2007, Vol. 16, no. 4

Business News from the Iowa Department of Economic Development

Domprosten Olavi Kares 16.1.1962 Åbo

Kirje

Report on a review of selected general and application controls over the Iowa Public Employees’ Retirement System (IPERS) Benefits Administration System for the period April 23, 2007 through May 16, 2007

Report on a review of selected general and application controls over the Iowa Public Employees’ Retirement System (IPERS) Benefits Administration System for the period April 23, 2007 through May 16, 2007

Iowa Developments, September 2007, Volune 16, Number 5

Business Development news from the Iowa Department of Economic Development

Opetusministeri Johannes Virolainen 16/11 1968

Kirje 16.11.1968