Techniques are disclosed to provide randomized signal transforms andor their applications. A method for operating the air conditioning unit is also provided. Each of the pixels is converted into a Lab color space to obtain luminance and chrominance values. The terraced trench has a plurality of portions that differ in width to define at least one annular ledge therebetween. It is preferable that the laser cutting section irradiates the media in an immobile state with laser beams, and the print section applies ink to the media in which the immobile state is maintained. The magnet members for compensating the magnetic field are disposed at positions where temperature change in the vacuum chamber is not transferred to the interior of the vacuum chamber.