Several 2–(46, 6, 3) designs

Adaptive Biased-coin Designs for Clinical Trials with Several Treatments

Adaptive designs are used in phase III clinical trials for skewing the allocation pattern towards the better treatments. We use optimum design theory to provide a skewed biased-coin procedure for sequential designs with continuous responses. The skewed designs are used to provide adaptive designs, the performance of which is studied numerically for designs with three treatments. Important prope...

Optimal discriminating designs for several competing regression models

The problem of constructing optimal designs for a class of regression models is considered. We investigate a version of the Tp-optimality criterion as introduced by Atkinson and Fedorov (1975b) and demonstrate that optimal designs with respect to this type of criteria can be obtained by solving (nonlinear) vector-valued approximation problems. We provide a characterization of the best approxima...

Pns1200302 246..250

Over the past two centuries human life expectancy has increased by nearly 50 years. Genetic factors account for about one-third of the variation in life expectancy so that most of the interindividual variation in lifespan is explained by stochastic and environmental factors, including diet. In some model organisms, dietary (energy) restriction is a potent, and highly reproducible, means of incr...

Constructions of 3-resolvable nested 3-designs and 3-wise balanced designs

The parameters 4-(12, 6, 6) and related t-designs

It is shown that a 4-(12,6,6) design, if it exists, must be rigid. The intimate relationship of such a design with 4-(12,5,4) designs and 5-(12,6,3) designs is presented and exploited. In this endeavor we found: (i) 30 nonisomorphic 4-(12,5,4) designs; (ii) all cyclic 3-(11,5,6) designs; (iii) all 5-(12,6,3) designs preserved by an element of order three fixing no points and no blocks; and (iv)...