In one technique, a desired electrical current distribution on at least three active electrodes is selected. An upper arm is coupled, through a joint, to one side of the operating unit. As such, the torque required for a first driving device and a second driving device to rotate and drive the end effecter can be reduced. The rotational speed of the cup is varied so as to control a thickness of the liquid film in the cup to between 200 and 1000 \u03bcm. The present invention processes each user input pattern profile to identify a demographic type.