Analysis of the Effect of Daqu's Physical and Chemical Parameters on Liquor Quality Using Rough Sets

Daqu is important for Chinese liquor production, and it determine the yield as well as quality of Chinese liquor. Daqu can be evaluated through the physical and chemical indicators such as the esterifying power($EP$), liquefying power($LP$), saccharifying power($SP$), fermenting power($FP$), acidity, starch and moisture. These characters have different effect in liquor production. Duqu's significant physical and chemical attributes affected on liquor quality are studied using rough set theory. The information table has been built with these seven physical and chemical indicators of Daqu as conditional attributes, with the Chinese liquor quality level as decision attribute. The table are quantized and reduced, then it is shown that the acidity, esterifying power and saccharifying power are the main indicators impacting on the liquor quality. Based on the conception of weight, we find that the weights of three indicators are $25\%$, $25\%$ and $50\%$, which indicates that, the saccharifying power has most effect on the liquor quality, while the effects of acidity and esterifying power are the same.