Methods and apparatus for collection, validation, analysis, and automated error correction of data regarding user interaction with content. Filter discs or other suitable substrates are impregnated, by the process of adsorption, with solutions of known concentrations of analytes and chromatographic phase materials, such as polymers, in suitable solvents. The first wavelet transform unit performs a discrete wavelet transform on an original image of a two-dimensional code and decomposes this into various frequency components, namely an LL component, an LH component, an HL component and an HH component. The system includes a plurality of transmission queues for temporarily storing transmission data provided in the control station, wherein one of the queues holds transmission data for the second communication. Each magnetic coil is at least partially received in the groove to save space for reducing profile of the connector. Shock absorbing member is provided with at least two flanges protruding from at least two edges formed by at least two sets of neighboring walls among a plurality of walls, and the at least two flanges are arranged so that the directions of protrusion of the flanges from the edges are directed to the same direction with respect to a circumferential direction.