Abstract: According to some embodiments of inventive concepts, vertical nonvolatile memory devices and related methods may reduce chip size. The nonvolatile memory device may include a substrate wherein a first direction is orthogonal with respect to a surface of the substrate and wherein the substrate includes a cell array area and an extension area. A first gate structure layer on the substrate may include a plurality of first gate layers. A contact separation layer may be on the first gate structure layer on the extension area. A second gate structure layer on the first gate structure layer and on the contact separation layer may include a plurality of second gate layers. A plurality of channel structures may extend in the first direction through the first and second gate structure layers on the cell array area. A plurality of first metal contacts may extend through the first gate structure layer in the first direction between the substate and the contact separation layer in the extension area.

Abstract: A welding gun is incorporated into a unidirectional welding system, where the unidirectional welding system includes: the welding gun performing welding when a set pressing force is applied; a power portion configured to generate power to be applied to the welding gun; a power connecting portion having one end portion connected to the power portion through a power wire and an opposite end portion engaged with the welding gun; and a power switch provided at the power connecting portion to selectively apply the power generated from the power portion to the welding gun.

Abstract: A welding gun is incorporated into a unidirectional welding system, where the unidirectional welding system includes: the welding gun performing welding when a set pressing force is applied; a power portion configured to generate power to be applied to the welding gun; a power connecting portion having one end portion connected to the power portion through a power wire and an opposite end portion engaged with the welding gun; and a power switch provided at the power connecting portion to selectively apply the power generated from the power portion to the welding gun.