The research platform for underwater wet welding is designed and high frequency ultrasonic sensor is put into use, The research platform comprises four independently movable shafts which names as X, Y, Z and A axis, The four axes are driven by servo motor and stepping motor, The features of both servo motor and stepping motor are analyzed at first, and then the relationship between the moving s...

We review recent work on the application of fluctuation analyses of time series for pattern classification in nondestructive materials inspection. These analyses are based on the evaluation of time-series fluctuations across time intervals of increasing size, and were originally introduced in the study of fractals. A number of examples indicate that this approach yields relevant features allowi...