Abstract: According to an embodiment, a system includes an electronic device, a server, and an output device. The electronic device may perform user authentication together with the server. The server may specify first content based on the user authentication and may transmit first metadata of the first content to the electronic device. The electronic device may visually output a first object representing the first content based on the first metadata, and transmit, when at least one object is selected of the output objects by the user, identification information of content represented by the selected object to the server. The server may output content corresponding to the identification information through the output device. Moreover, various embodiment found through the present disclosure are possible.

Abstract: According to an embodiment, a system includes an electronic device, a server, and an output device. The electronic device may perform user authentication together with the server. The server may specify first content based on the user authentication and may transmit firs metadata of the first content to the electronic device. The electronic device may visually output a first object representing the first content based on the first metadata, and transmit, when at least one object is selected of the output objects by the user, identification information of content represented by the selected object to the server. The server may output content corresponding to the identification information through the output device. Moreover, various embodiment found through the present disclosure are possible.

Abstract: Disclosed is a user equipment that supports device-to-device communication. A user equipment according to an embodiment of the present invention comprises: a communication unit for broadcasting a discovery message for informing another user equipment of the user equipment itself, and receiving a discovery message broadcasted from another user equipment; and a control unit for, when at least one discovery message is received, extracting an ID of at least one other user equipment from the at least one received discovery message, selecting at least one ID out of the extracted ID on the basis of status information indicating an importance of the at least one other user equipment, and broadcasting a discovery message including the selected ID.

Abstract: Disclosed is an apparatus for photographing a radioactive substance by using a smart device, the apparatus including: a radioactive information collection unit including a camera barrel, a dark curtain as a visible light blocking filter provided at an object-side extremity of the camera barrel, and an intensifying layer being sensitive to radioactive rays and generating visible light by being provided on a rear surface of the dark curtain; a smart device; a mount coupled to the radioactive information collection unit by being mounted at an eye-side extremity of the camera barrel such that an optical axis of a camera lens of the smart device matches up with an optical axis of the camera barrel; and an application provided in the smart device for calculational processing and output of image information produced via the radioactive information collection unit.