Abstract: When using nondestructive acoustic impulse response method to assess physical qualities of eggs and check cracks of eggshell, it can be found that there are lots of factors affecting dominant resonant frequency, such as eggshell strength, egg-shaped index, egg weight, and egg specific gravity. Furthermore, the relationship among these factors and dominant resonant frequency is non-linear and it is difficult to analyze the relationship among them through conventional regression method. In the paper, the grey relative coefficient among the dominant frequency and affecting factors of eggs are calculated with the grey relative theory. As shown in the results, the order of grey relative degree is as follows: eggshell strength, egg weight, egg-shaped index, and egg specific gravity. From the results, conclusion can be drawn that eggshell strength is the first important affecting factor, and the egg weight is the second, while the factor of egg specific gravity only affects the dominant resonant frequency slightly. In brief, the presented grey relative theory can provide a new way for comprehensive analysis of the relationship among dominant frequency and affecting factors.

Key words: eggs, grey reative theory, affecting factors, grey relative coefficient