A simple inertial or Doppler navigation has a common defect that position errors are always increasing with flight time or distance, therefore an external reference system is necessary.

Wavelet analysis and neural networks combine together, can examining the position and size of the hole defect, achieving wood defect quantitative testing.

The defect of" the possible world" with the position of moumenon leads to the thought of" the possible world" without the position of moumenon.