Abstract: Provided is a hazardous facility control method performed by a central server. The hazardous facility control method includes: receiving a maintenance mode setting request and a tag of a worker recognized by a safety device provided in a hazardous facility; authenticating the worker based on the tag; setting, to a locked state, an operation screen of a facility control device capable of controlling the hazardous facility, so as to block another worker from controlling the hazardous facility; and releasing a lock of the safety device so as to allow the worker to access the hazardous facility, and setting a state of the hazardous facility to a maintenance mode.

Abstract: Provided is a hazardous facility control method performed by a central server. The hazardous facility control method includes: receiving a maintenance mode setting request and a tag of a worker recognized by a safety device provided in a hazardous facility; authenticating the worker based on the tag; setting, to a locked state, an operation screen of a facility control device capable of controlling the hazardous facility, so as to block another worker from controlling the hazardous facility; and releasing a lock of the safety device so as to allow the worker to access the hazardous facility, and setting a state of the hazardous facility to a maintenance mode.

Abstract: A method for assembling a clip for a mobile phone retainer having a slider connection, the clip including a top plate and a bottom plate including fitting a clip retaining member into a through hole formed at the center of the bottom plate of the clip, fitting insertion protrusions of a slider plate to corresponding insertion holes of the clip retaining member, welding the slider and clip retaining member together while the insertion protrusions are fitted into the insertion holes, and connecting the top plate of the clip to the bottom plate using a hinge.

Abstract: A hollow golf club head made of a metallic material. The golf club head has a three piece structure, a main head body, face, and crown. The main head body and the crown are formed by casting or press-forming, the face is formed by press-forming, and these are joined together by welding. The metallic material used is selected from a steel material group of martensite deposition hardening-type stainless steel, maraging steel, and maraging stainless steel. Only a material having a specific gravity of 7.7 or higher is used, and the head body has a volume of 280-320 cc and a weight of 180-205 g. The golf club head enables increasing the meet rate, has design freedom, exhibits excellent processability, and can be manufactured at a low cost.

Abstract: A hollow golf club head made of a metallic material. The golf club head has a three piece structure of a main head body, face and crown. The main head body and the crown are formed by casting or press-forming, the face is formed by press-forming, and these are joined together by welding. The metallic material used is selected from a steel material group of martensite deposition hardening-type stainless steel, maraging steel, and maraging stainless steel. Only a material having a specific gravity of 7.07 or higher is used, and the head body has a volume of 280-320 cc and a weight of 180-205 g. The golf club head enables increasing the meet rate, has design freedom, exhibits excellent processability, and can be manufactured at a low cost.