One embodiment relates to a method of classifying a defect on a substrate surface. Each image frame in the first sequence of image frames is associated with a time position on a first timeline. A resiliently flexible target material can also be used for reliably holding a suture during the procedure. A control unit increasesreduces an amount of AC power output of the bidirectional DCAC converting unit based on an amount of current detected by the current detecting unit, thereby to control a supply of electric power to each load. The adjustment mechanism includes a bracket, a tension adjustor, and a tensioning wire attached to the bracket and the tension adjuster. The safety apparatus includes a fixed housing that is fixed to a vehicle body and a movable housing that is movably disposed in the fixed housing to move due to external impact.