Methods and apparatus for operating a user equipment for a wireless communication system. The embodiments a wood burning pen equipped with two receiver tubes angled 0. Accordingly, it is possible to sufficiently compensate for etch damages, prevent generation of abnormal oxidization in a metal layer, and improve the reliability of a process and electrical characteristics of a device accordingly. The optical head assembly is moved by the calculated distance toward the burst cutting area. A set of vague classes is identified from the overlapping semantic tokens and the initial target classes. The invention can also include a first conductivity type channel stopper layer which is formed on a chip outer circumferential side of the first clip layer so as to be separated from the first clip layer and which is higher in concentration than the n-type drift layer.