Journal of The Japanese Society for Quality Control

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The main reason why power transformation to normality is applied to positive-valued observations coming from a skewed distribution is due to richness of normal theory and flexibility of a power parameter describing a wide class of distributions. In this paper, first we show that an approximate median formula of the F distribution derived from power transformations of the F variable gives an approximate formula of the median rank. Its accuracy seems of practical use. Second, an application of the Wilson-Hilferty transformation formula for the F variable to χ^2 enables us to construct a normal probability plotting for sum of squares with different degrees of freedom in an analysis of variance(ANOVA). Plotting positions are determined by our formula of the median rank. A supplementary use of probability plotting in ANOVA provides an easy guidance to remove our preconceptions on factors. Finally, a statistical model for the joint modelling of location and dispersion effects is introduced by a power normal family derived from the generalized F distribution through the Wilson-Hilferty transformation formula for the F variable. Our modelling is, unlike approaches based on Box-Cox power normal family, near the spirit of generalized linear models and the model is statistically tractable.

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This paper investigated consumer's quality requirements for five products from the viewpoint of the "attractive quality" and "must-be quality" proposed by Noriaki Kano et al, and then developed a model for explaining the consumer's recognition of individual quality items and the effects of type of product and feature of consumer on the recognition, i.e., whether a group of consumer having a certain feature recognizes each quality item as attractive, must-be, or others. According to the results, whether a quality item is recognized as attractive, must-be or others depends on the category of the item, and is affected by type of product. Feature of consumer also has effects, with the degree of the effects being not critical.

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SMBP(Strategic Management by Policy)has been already applied to the differential type of business such as Canon copier business. This paper studies the applicability of SMBP to the scale merit type of business, i.e.LSI, mobile phone, LCD which is growing rapidly and needs sufficient cash flow, because the initial investment cost is very high.In this paper new framework and evaluation indicators of business profitability for SMBP to be applied to the scale merit type of business are proposed in consideration of reducing business risk. Finally above SMBP framework and evaluation method are verified to be useful for the scale merit type of business through the case study of mobile phone business.

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In this paper, we discuss the recent trends of various quality activities based on the contents of 55^<th> Annual Quality Congress(AQC)held by American Society for Quality(ASQ)and the authors experience to join 55^<th> AQC. The examination of the 55^<th> AQC contents shows the keywords of the recent quality trends in America as follows : quality and cost, speed, competition and globalization.

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