By studying treatment contrasts and ANOVA models, we propose a generalized minimum aberration criterion for comparing asymmetrical fractional factorial designs. The criterion is independent of the choice of treatment contrasts and thus model-free. It works for symmetrical and asymmetrical designs, regular and nonregular designs. In particular, it reduces to the minimum aberration criterion for ...

Agro-residues were used as the substrate for the production of fibrinolytic enzyme in solid state fermentation. In this study, two-level full factorial design (25) and response surface methodology were applied to optimize a fermentation medium for the production of fibrinolytic enzyme from the marine isolate Shewanella sp. IND20. The 25 factorial design demonstrated that the physical factors (p...

To prevent a premature failure, absorbable magnesium implants must possess an adequate mechanical stability. Among many ways to improve the properties of is by particle reinforcement, such as using carbon nanofiber (CNF). This work reports experimental design for optimum materials and processing CNF-reinforced Mg–Zn composites based on two-level factorial design. Four factors were analyzed: per...

An A-optimal minimax design criterion is proposed to construct fractional factorial designs, which extends the study of the D-optimal minimax design criterion in Lin and Zhou (Canadian Journal of Statistics 41, 325–340, 2013). The resulting Aoptimal and D-optimal minimax designs minimize, respectively, the maximum trace and determinant of the mean squared error matrix of the least squares estim...

Number of findings have shown that the used vegetable oils (UVOs) properties can be enhanced by changing their chemical structure and utilized as dielectric liquid in oil-immersed transformers. However, earlier researchers one-factor-at-a-time (OFAT) method for experimental design approach. Nevertheless, they failed to consider possibility combining mixing process parameters at highest ratios c...