A portable electronic device such as a mobile phone comprises two body parts moveably connected by hinges. When the metal particles contained in the conductive paste are sintered to form a unified conductive compound, the volume of the conductive paste shrinks. Furthermore, the first region includes a first material selected from the group consisting of carbides of transition metals, nitrides of transition metals, and borides of transition metals. Symbol synchronization is rapidly inferred from the field synchronization and data segment synchronization, so that the samples in each data line can be counted.