Circuits and methods to improve dynamic load transient performance of circuits supplying high current and having parasitic resistances are disclosed. There is also disclosed a document holder formed of such a metal fitting as attached to a base member. Each has a rotor tip clearance notch. The present invention relates to a production process for a silsesquioxane derivative represented by Formula, characterized by using a silicon compound represented by Formula. The resistance R of the insulating layer is measured over the linear section of the voltage-current curve and the temperature T is determined from the equation: 1R=1R02),.