Additive drag perturbation method for measuring active drag in swimming;

This paper gives a general introduction of several measurements of active drag in swimming:MAD method, velocity perturbation method, bioenergetic method, model method, towing method, etc.

This paper has made study on the experimental measuring, numerical simulation and theoretical derivation of swimming optimization, which includes details as following:Because of the difficulty in directly measuring the active drag in swimming, this paper designed a set of system-Additive Small Drag Method to measure it indirectly, which can be used as a training device also.

Studies of dynamic resistance in resistance spot welding;

Analysis on dynamic resistance in resistance spot welding of stainless steel;

According to the changing rule of resistance in the process of discharge, the changing rate of instantly dynamic resistance is monitored.

In this paper,one of the quality controls in resistance welding,the dynamic resistance method is introduced,and any problem of resistance electric welding machine in using are analyzed in detail.

The measurement of microwave dynamic impedance under high power level is suggested in this paper.

To distinguish magnetizing inrush currents more effectively from internal faults in transformers,an identification strategy was proposed on the basis of dynamic impedance characteristics,which possesses very straightforward physical meaning.

The equipment mostly check up background currents,leakage-current,dynamic impedance and C-V characteristic etc.