Aiming at problems in current study of sonar image enhancement,a new enhancement method based iterative threshold was presented,the criterion function and frequency response were used to evaluate and compare current image enhancement arithmeti.

A modification to Linearly Decreasing Weight strategy in standard Particle Swarm Optimization is taken by introducing descending index and iterative threshold.

The identification card scanned image is seriously affected by laser restraining false shadow grid, several binarization methods of document image are studied according to this characteristic, an image binarization method is proposed , which is called iterative threshold methodbased on the neighborhood feature of the pixels .

Using the method of discretization and numerical iteration, the precise visualization results of the distributions of electric field and charges are obtained by Matlab numerical simulation.

With the numeric calculating method applied to the reservoir flood routing operation,we introduced the numerical iteration,a new method which makes porgramme designing for flood routing operation easier.

Tradional algorithms to solve POMPDs are value iteration algorithm and policy iteration algorithm.

Point-Based value iteration algorithms are effective proximate algorithms to solve POMDP problems.

DTIE could be employed to provide the iterative initial value implementing M-step in some EM algorithms.