Starting from the features of the structare of phono-based charecters, the author analyses thenumber of characters constructed from the phonetic notations of commonly used phono-based characters in modernChinese languag.

Since XML Schema can t be directly converted into relation-model,the authors design the structure information and constraint information of structure dictionary,and apply a greedy algorithm to realize the mechanism mapping to be relation model.

Seemingly it is because of carelessness,but essentially,it is of the words structure and people s carelessness who use words,especially morphemes with low frequency.