Function spaces defined by scaling functions are used to generate bandlimited noise octaves and other attribute data sets. Individual steel panels are assembled to form a series of upstanding walls which are covered by a series of roof panels and which together define the quasi-enclosed area surrounding the well head. The locator member is inserted into a lumen of the tubular member until a distal portion is disposed beyond the plug. A third metal layer is formed on the second metal layer through still another insulating layer and divided into a plurality of parts by third slits. In addition, the insulating plates and are disposed extending in the direction to which the pairs of terminals are connected. The method of extracting an important frequency component of an audio signal includes converting an audio signal of a time domain into an audio signal of a frequency domain, selecting a frequency band having a harmonic feature from the converted audio signal of the frequency domain, and extracting an important frequency component from the selected frequency band having the harmonic feature.