In the first study, it 'recommend an initial ratio of repairing material based on system analysis by orthogonal test method which explore the general using scope about kinds of raw materials.

On the other hand, if possible, a physical model to meet the product requirements, and according to the initial ratio of simplified, so that anyone can design and modeling of the correct evaluation.

So ever fewer cases are going to trial: the ratio of federal trials to initial filings in 2009 was a twelfth of what it was in 1962.