An image forming apparatus uses the difference in time taken for each patch to reach a color sensor, which occurs upon reversing the conveyance direction of a printing material. The carbon-fibre sheet lies pressed in the end fitting by means of at least on wedge. In each solution cycle of a time-marching simulation, each of the elements of porous material is evaluated with airflow in conjunction with the traditional mechanical response. In various embodiments, the LNA includes a second attenuator configured to generate a third intermediate signal. According to the present invention, the reduction characteristics and performance of the cell devices of NAND flash memory are improved, and the inversion layer of a channel is induced through fringing electric fields from the control electrode and the charge storage node if necessary.