Under a very simple constrain from the Maximum Entropy Principle, we found that an intensity-duration relation of Precipatation processes obeys negative exponent law.

Higher costs for raw materials such as steel, aluminum and rubber may constrain automakers from taking advantage of record global sales this year, Fitch's Brown said in a telephone interview.

In this paper, the guide and constrain concept are put forward with some examples, from the concept of the public facilities.