Renyi (Bull. Amer. Math. Soc. 71 (6) (1965) 809) suggested a combinatorial group testing model, in which the size of a testing group was restricted. In this model, Renyi considered the search of one defective element (signi5cant factor) from the 5nite set of elements (factors). The corresponding optimal search designs were obtained by Katona (J. Combin. Theory 1 (2) (1966) 174). In the present ...

Martin J. Sharry and Anne Penfold Street, Centre for Combinatorics, Department of Mathematics, The University of Queensland, Brisbane 4072, Australia. As a first step towards finding all 4-(12, 6, 4) designs which are not 5-(12, 6, 1) designs, it is shown that if such a design has a pair of blocks with five points in common, then there is a unique way of assigning the replicas of the seven poin...

Shahzad A Malik is a visiting fellow at the School of Surveying and Spatial Information Systems, University of New South Wales, Australia. He received a Bachelors degree in Electrical Engineering from Riphah International University, Islamabad, Pakistan. He is currently a Lecturer at the Faculty of Engineering and Applied Sciences, Riphah International University. His research interests include...

In some experiments in the physical and biological sciences, a binary response is of primary interest and is often described by a generalized linear model. Examples include experiments in food technology and studies in chemistry where the outcome is whether or not a salt is formed in a chemical reaction. For such experiments, designs that are efficient under the assumption of a linear model may...

In the optimization of engineering designs, traditional search and optimization methods face at least two diiculties: (i) since each is specialized in solving a particular type of problem, one method does not work well on diierent types of problems (ii) most of them are designed to work on continuous search spaces. Since diierent optimal engineering design problems give rise to objective and co...

Shape grammars play an important role in a new generation of tools for the analysis and design of products. Up until now there has been numerous attempts to create a general shape grammar interpreter, but most of the existing tools are either very specific in their purpose, have only limited functionality or were programmed for one operating system. In this work we present a tool named Shape Gr...

It is difficult to build intelligent computer-aided design (ICAD) programs using available expert system shells and AI programming languages. To build ICAD programs, tools are needed that support (a) generative search of design spaces, (b) deep search of design spaces to evaluate alternative designs, (c) simultaneous exploration of alternative designs to compare designs, (d) constraint posting ...

Censoring may occur in many industrial or biomedical ‘time to event’ experiments. Efficient designs for such experiments are needed but finding such designs can be problematic since the statistical models involved will usually be nonlinear, making the optimal choice of design parameter dependent. We provide analytical characterisations of locally Dand c-optimal designs for a large class of mode...

The effectiveness of surrogate based optimization of helicopter rotor blades for vibration reduction using kriging global approximations is investigated. The search for the optimal design is conducted using two methods: (1) the “one-shot” approach in which the surrogate is optimized directly and (2) a method based on the expected improvement function which seeks to find optimal designs while re...

Scatter Search and its generalized form Path Relinking, are evolutionary methods that have been successfully applied to hard optimization problems. Unlike genetic algorithms, they operate on a small set of solutions and employ diversification strategies of the form proposed in Tabu Search, which give precedence to strategic learning based on adaptive memory, with limited recourse to randomizati...