A method and apparatus for performing design verification is described. The intermediary may be deployed between a client and the remote access server farm and forwards client requests to functional components of the remote access server farm. The input flow information is then fetched. The punching section is corrected in position, at both the leading edge of the sheet and the trailing edge thereof, thus increasing the precision of positioning the punching section and shortening the time required to position the punching section. The light transmittance of the correction pattern is adjustable so as to equalize the light intensity distribution of the primary mask.