Based on the general weighted length, combined with the level characteristic value, a new method is put forward to evaluate the environmental noise of railway with fuzzy.

According to fuzzy idealsolutionand generalized weighted distance, the group consistence and group inconsistence aredefined, and the fuzzy multiple attribute decision-making model on the trapezoid fuzzy number is established.

By usage of generalized distance of weight, assessment results are more dispersed, so that the risk grades are easier to be distinguished.

Generalization of a class of iterative means in generalized weighting;

Samples weights are properly solved through introducing the concept of weighted distance between weighted sample and hyperplane.

The weighted distance between two adjacent intervals is defined using relative class frequency in the algorithm.

The algorithm can simplify mesh models effectively, it also uses distance-weighting for viewport-clipping, results in view-dependent simplified mesh model.