A method for analyzing computer network security has been developed. In one example, a mask display system comprises a head portion, a pair of hands attached to the head portion, and a suspension system, serving as a novelty simulation of a peeping tom. The model receives input from a user and from a database of various characteristics for a plurality of decoupling components. The material of said shield arrangement can be covered with a film of dielectric material and electrically connected to ground through said substrate holder. The thickness of the second semiconductor region in the channel lengthwise direction is set to a value equal to or less than depletion layer width determined by the impurity concentration so that the second semiconductor region is depleted in a no-voltage application state.