Abstract: Various example embodiments of the disclosure relate to an electronic device and a wireless communication connection control method thereof.

Abstract: The present invention relates to a carbon-ceramic brake disc, and the present invention includes a plurality of heat dissipation holes formed in a frictional surface; a curved surface formed between the frictional surface and an inner surface of the hole dissipation hole; and a groove formed at the inner surface of the heat dissipation hole. According to the present invention, in a brake system, when brake pads press the frictional surfaces of the carbon-ceramic brake disc brake to generate braking force, frictional heat in the carbon-ceramic brake disc is effectively dissipated to the outside. That is, the carbon-ceramic brake disc is effectively cooled. Thus, the transferring of the frictional heat generated in the carbon-ceramic brake disc to a hat part is reduced, so that it is possible to minimize deformation of the carbon-ceramic brake disc and the hat part.

Abstract: A method of manufacturing a carbon-ceramic brake disc of the present invention includes a first step of mixing carbon fibers with phenolic resins to produce a mixture; a second step of putting the mixture into a mold pressing the mixture by a press to produce a molded body; a third step of carbonizing the molded body; a fourth step of machining the carbonized molded body; a fifth step of coating the machined molded body with liquid-phase phenol to be cured; a sixth step of melting silicon to be infiltrated into the cured molded body that has been coated with the liquid-phase phenol; and a seventh step of grinding the molded body that has been infiltrated by the silicon. According to present invention, the cracks do not occur in the anti-oxidation coating layer.

Abstract: The present invention relates to a carbon-ceramic brake disc, and the present invention includes a plurality of heat dissipation holes formed in a frictional surface; a curved surface formed between the frictional surface and an inner surface of the hole dissipation hole; and a groove formed at the inner surface of the heat dissipation hole. According to the present invention, in a brake system, when brake pads press the frictional surfaces of the carbon-ceramic brake disc brake to generate braking force, frictional heat in the carbon-ceramic brake disc is effectively dissipated to the outside. That is, the carbon-ceramic brake disc is effectively cooled. Thus, the transferring of the frictional heat generated in the carbon-ceramic brake disc to a hat part is reduced, so that it is possible to minimize deformation of the carbon-ceramic brake disc and the hat part.