An epitaxial substrate includes: a base member; and a plurality of spaced apart light-transmissive members, each of which is formed on and tapers from an upper surface of the base member, and each of which is made of a light-transmissive material having a refractive index lower than that of the base member. The system having an information processor configured to receive origination information for the call including identifying information of the call originator. If all elements corresponding to the same bin number exceed a predetermined threshold, the elements are multiplied by correction matrices to yield corrected, DFT terms for a reconstructed power spectrum. A cover is attached to the heating plates and the body portion. The arm and the hook are sized and configured so that the leg and the hook can engage opposite surfaces of the roofing shingle. The optical thin film determines a component of light transmitted through the optical thin film and light reflected from the optical thin film.