Abstract: A hydrogen supply method includes a two-side heat exchange mode in which both introducing a second fluid into a hydrogen storage part after the second fluid exchanges heat with a first fluid in a second heat exchanger in a state in which a compressor is driven to compress the first fluid and introducing the second fluid into the hydrogen storage part after the second fluid is heated or cooled in the thermal device are performed. The method also includes a one-side heat exchange mode in which one of introducing the second fluid into the hydrogen storage part after the second fluid exchanges heat with the first fluid in the second heat exchanger in a state in which the compressor is driven to compress the first fluid and introducing the second fluid into the hydrogen storage part after the second fluid is heated or cooled in the thermal device is performed.

Abstract: A propulsion module of an air mobility vehicle may include a door provided in the housing and opening or closing the opening portion of the housing by a sliding motion of the door; a propeller for providing propulsion to the air mobility vehicle; a link assembly having a first end portion connected to the housing and a second end portion connected to the propeller to pull the propeller into the internal space of the housing through the opening portion or pull the propeller outside the internal space through the opening portion; and a door opening and closing portion coupled to the door and configured for providing an opening and closing force to the door according to an inward-pulling motion or an outward-pulling motion of the propeller.

Abstract: A shoes care device includes an inner cabinet configured to accommodate shoes inside; a outlet configured to suck air inside the inner cabinet; a nozzle duct having one end hinge-coupled to the inner cabinet so as to protrude into the inner cabinet, and which forms a passage for air; a nozzle hinge-coupled to the other end of the nozzle duct so that the shoes can be inserted into the inner cabinet, and configured to inject air into the shoes; a nozzle connector, of which one end is hinge-coupled to the inner cabinet and of which the other end is hinge-coupled to the nozzle; a connection path from the suction to the nozzle; a blowing part in the connection path and configured to ventilate air from the outlet to the nozzle; and a dehumidifying part in the connection path and capable of dehumidifying the ventilated air.

Abstract: A shoes care device includes an inner cabinet having an accommodation space configured to accommodate shoes; a outlet formed on a bottom of the inner cabinet so as to suck air inside the inner cabinet; a connection path forming a flow path through which air in the accommodation space is discharged from the inner cabinet through the outlet and then introduced back into the accommodation space; a blowing part disposed in the connection path and configured to ventilate air; a dehumidifying part disposed in the connection path and configured to dehumidify air; and a main shelf installed to cover the bottom of the inner cabinet and having an upper surface on which the shoes can be settled.