Electric Heating Cable Fault Testing System Based on Wavelet Packet and RBF Neural Network
A new method for testing of the electric heating cable fault was proposed,which was based on the wavelet packet and RBF (radial basis function) neural network. The principle used for testing the short-circuit fault of the electric heating cable was described. The flow chart of the detecting system was given. Experimental results showed that the method, which combined the wavelet packet and RBF neural network, could be used to improve the effectiveness of locating the electric heating cable fault.
A Device for Fault Testing of the Underground Electric Heating Cable
This paper introduced a new type of fault testing device for underground electric heating cable. A new design concept was adopted and intelligent control techniques were used in the trouble-shooting testing system for buried electric cable. The testing principles of the short-circuit fault point and the breaking point were discussed. The performance and functions of the device were described.
Microstructure of the solder-casting zone in bridges of dental gold alloys.
The composition and structure were studied in the cast and in the solder of bridges which had failed clinically. Both materials were gold alloys but with different contents of Pt, Ag and Zn. The metallographic investigation revealed defects mostly in the solder, situated in the subsurface layer. SEM studied of the fracture surface revealed large porosites and a structure of dense parallel lines--striations--, indicating that the material had failed from fatigue. The materials in the fractured bridges were identified by micro-probe measurements. It was stated that cast material and solder material used together, were of different composition.