The present invention proposes a method, including receiving a sequence of channelization encoded correlated symbols xi, analyzing statistical or orthogonality properties of the sequence, and deciding on presence or absence of a specific control channel based on the analyzed properties. JPEG compressed image data are received that represent an input digital image, and the JPEG compressed image data include a plurality of DC components. The case and the end plates are connected to one another by a hinge mechanism in which pins are engaged into through-holes of tab sections to provide a fuel cell stack. Inventive fuel cells having a membrane electrode assembly that comprises a membrane of the invention and phosphoric acid as the doping agent have, for example, an impedance of 0. Methods of making the surface covering are further described.