The fluctuations are analyzed in amplitude, frequency, and phase of the sinusoidial signal in the experiment of the measurement of the frequencies of the unknown electrical signals by means of Lissajou figure , the causes of the error investigated and the methods to determine the relative error value found out.

With the theory, any straight lines and quadratic curve′s equidistance curve can be indirectly interpolated with the help of outline and wire circle′s information, it is unnecessary to calculate equidistance curve.

Rational approximation of offset curves by s-power basis;

A new method of rational approximation of the offset curves of planar Bézier Curves;

To some extent, using a plane curve to approximate an offset curve of the plane Bézier curve is restricted.