to evaluate the effect of growth promoting bacteria on morphophysiologic traits and nutrient uptakes of two rice cultivars, an experiment was carried out in 2009-2010 cropping season in rice researches institute of rasht. the experiment design consisted of four randomized complete blocks in a factorial arrangement having 16 treatments in 4 replications. in this research, two factors were evalua...

SUMMARY We propose a general and unified approach to the selection of regular fractional factorial designs which can be applied to experiments that are unblocked, blocked, with random or fixed block effects, or have a split-plot structure. Our criterion is derived as a good surrogate for the model-robustness criterion of information capacity. In the case of random block effects, it takes the ra...

In a two-level factorial experiment, we consider construction of parallel-flats designs with two identical parallel flats that allow estimation of a set of specified possibly active effects and the pure error variance. A set of sufficient conditions is presented for the designs to be D-optimal for the specified effects, assuming that the other effects are negligible, over the class of competing...

Article history: Received 2 August 2008 Received in revised form 1 July 2009 Accepted 2 July 2009 Available online 9 July 2009

We present some optimal criteria to evaluate model-robustness of non-regular two-level fractional factorial designs. Our method is based on minimizing the sum of squares of all the off-diagonal elements in the information matrix, and considering expectation under appropriate distribution functions for unknown contamination of the interaction effects. By considering uniform distributions on symm...

Regular two-level fractional factorial designs are often used in industrial experiments as screening experiments. When some factors have levels which are hard or expensive to change, restrictions are often placed on the order in which runs can be performed, resulting in a split-plot factorial design. In these cases, the hard or expensive to change factors are applied to whole plots, whereas the...

The present investigation uses arc voltages, current, welding speed, wires feed rate and nozzle-to-plate distance as process parameters. Two level full factorial a technique has been used for experiment design. Multiple regression analysis has been used to develop a mathematical model to predict weld width using a single wire Submerged arc welding depositing bead-on-plate welds on 12mm plate. A...