A chair seat pan comprising a reinforced rear region, a reinforced pommel region, a pair of forward flexible regions which resiliently flex with respect to the reinforced regions under external pressure, and a continuous upper surface throughout the reinforced rear region, the reinforced pommel region, and the pair of flexible regions, for supporting a user. A printer has a feed-in roller for feeding a sheet into a printing region, a feed-out roller for feeding the sheet out of the printing region, a motor for rotating the feed-in roller and the feed-out roller, and a controller for controlling the motor. The folded nanowires, located in the conceptually folded, two-layer nanowire-crossbar design, are collapsed into shorter length nanowires to give a multilayer nanowire-crossbar design that includes the same number of nanowire junctions as in the two-layer nanowire-crossbar design. Therefore, a long-time etching can be used to obtain a better through hole profile. The precoder is chosen as a function of either logical frequency index or physical frequency index of the RB. The sensor head and the sensor assembly or the associated projection system measurement elements are mounted on a sensor frame.