The traditional software reliability model is analyzed and researched,the problems of traditional model is pointed out, and the unascertained theory is introduced into research on software reliability.

To make the differences less,the possibilistic reliability method based on unascertained theory was put forward.

Software reliability was researched by the way of integrating unascertained theory and clustering,discarding all kinds of assumptions of distribution in software fault process and improving the incongruence of model application to some extent.

Assessment model of water quality risk based on unascertained mathematics theory;

Since the unascertained characteristic of stream sediments system, unascertained mathematics theories are applied to the assessment of heavy metal pollution in stream sediments.

A problem of allowable load of a predominant pollutant for main stream reservoir is preliminarily approached according to the theory of unascertained mathematics,on the basis of unascertained information of river hydrology and water quality.

Based on the uncertainty measurement theory, a risk prediction method of coal seams outburst was established.

Application of the unascertained rational number in the Optimization for the Advice of Experts;

Based on unascertained information theory and unascertained rational number, the method of solving unascertained expectation was used to solve the actual problem.

By the present method, not only can the unascertained expected value of the water environment capacity of river water bodies be calculated, but also its subjective reliability can be obtained on the basis of the rules of four fundamental operations of unascertained rational numbers.

Besides,the unascertained rational numbers module is introduced to calculate the concrete rebound value,which can set as an example when in the similar data processing situation.