Abstract: Disclosed herein are a method and apparatus for converting a credential data schema.

Abstract: Disclosed herein is a method for user-centered visitor access management, which may include issuing, by a management office server, a digital certificate to a householder terminal; registering, by a wall-pad, a householder in response to a request to register the householder based on the digital certificate; requesting, by the householder terminal, the management office server to register a visitor based on a visit request from a visitor terminal and delegating the digital certificate to the visitor terminal; making an entry request to a management terminal based on the digital certificate; verifying, by the wall-pad, the digital certificate based on a request for verification for entry from a wall-pad management terminal and providing a verification result to the wall-pad management terminal when the management terminal is the wall-pad management terminal; and managing and controlling, by the wall-pad, permission to use home devices based on delegated permission information of the digital certificate.

Abstract: A multistep focusing electron gun for a cathode ray tube includes at least a unipotential auxiliary lens and a bipotential major lens, wherein the electron beam-passing hole of the middle electrode supplied with a low potential among a successive three electrodes forming the unipotential auxiliary lens is formed in the form of a square and has a size so that the electron beam-passing holes of the electrode disposed at the front and at the rear of the middle electrode can be inscribed. The intensity of the unipotential auxiliary lens is weakened without reducing the mechanical strength of the electrode, and also the change of the relative position between the electrodes resulted from the structure change is inhibited.