The double-threshold binarization and morphological transform were applied to process the metallographical image. They could classify the grain and the grain boundary from gray metallographical image. Also, the eight-direction tracking techniques about Freeman chain encoding for metal metallographical compression had been discussed, and a grain boundary tracking algorithm was given. The experimental result shows that the proposed image processing method can segment grains and their boundaries efficiently. Freeman chain encoding can compress the stored data of metallographical image greatly. Compared with another compression method RLE, it has much higher compression effect.

The concepts and principles of layered design method and collaboratively using of different tools for developing network application system are presented in this paper. The recommended layered architectures are given respectively for the applications based on Client/Server model, Distributed Computing model and Web Database model. The advantages and disadvantages of layered design are also analyzed. At last, a realtime application example designed by layered architecture is given to illustrate its efficiency.

This study presented an insulation state monitoring method for large generator based on radio frequency (RF) technique. As an on-line condition monitor and the precondition of condition-based maintenance (CBM), the RF monitor used the high frequency current mutual inductor to detect the partial discharge signal from neutral wire of stator windings. According to the magnitude of indicative value of RF monitor, a five phase model was also proposed to manage the generator's running better. The practices show that the proposed method is effective.

In order to reform the shortcomings of common database with a slower access speed and lower security level, this paper applied sector operating directly instead of general file access, and used the distributed computing and clustering techniques to form an information server cluster as the special database system. Firstly, the layout and sector segmentation methods were provided for data access in sector based database. And then some management methods were given to control information servers in the cluster. Finally, to more efficiently schedule the tasks for storing data and querying information, a dynamic and self-adaptive scheduling algorithm was introduced into the application server of cluster. The practice shows that the system developed by this design strategy has good efficiency and security, and the access speed of the special database system is almost 25 times than that of common database.

Although the general random scrambling based on pixel can achieve a good chaotic effect, but it can not change the histogram of a digital image. We introduce the random scrambling into the domain of discrete cosine transform (DCT) of image and scramble the coefficients of DCT to improve the performance of scrambling. Firstly, we did 2-D discrete cosine transform to the original image. Secondly, we scanned the coefficients matrix of DCT by Zig-Zag scanning to get a 1-D sequence, and then we scrambled this sequence by 1-D random scrambling algorithm. Thirdly, we did inverse Zig-Zag scanning to the scrambled sequence and reconstructed the scrambled image from the chaotic coefficients matrix by 2-D inverse discrete cosine transform. Finally, to further improve the scrambling degree of the reconstructed result, we scrambled it again in space domain to gain the encryption image. Experiments show that this algorithm is effective at visual evaluation and is more stable in scrambling degree than Arnold transformation.