A neural network assisted multi-spectral segmentation method and system. In a computer system, a system recovery management unit produces backup as the initial status of volume and snapshot taken when the system is operating, by use of a backup restore processing unit of a storage apparatus, and manages the situations of the process by use of a recovery point listtable. When the trunnions and the power rollers are displaced by the servopistons in the trunnion axis direction in mutually opposite directions, the trunnions and power rollers gyrate around the trunnion axis as pivot, and a speed change will occur. The reflected radiation forms an interference pattern in the resist layer of the projected aerial image through the resist layer thickness.