Abstract: Disclosed are novel compounds of Chemical Formula 1, optical isomers of the compounds, and pharmaceutically acceptable salts of the compounds or the optical isomers. The compounds, isomers, and salts exhibit excellent activity as GLP-1 receptor agonists. In particular, they, as GLP-1 receptor agonists, exhibit excellent glucose tolerance, thus having a great potential to be used as therapeutic agents for metabolic diseases. Moreover, they exhibit excellent pharmacological safety for cardiovascular systems.

Abstract: An apparatus and method for simultaneous transmission scheduling in a multi-hop cellular system are provided, in which a base station presets simultaneous transmission relay station set information and transmits the simultaneous transmission relay station set information to relay stations managed by the base station, and an relay station receives the simultaneous transmission relay station set information from the base station, determines, upon receipt of a data frame from the base station, a state of the relay station preset in relation to a receiving relay station for the data frame by comparing an ID of the receiving relay station included in the data frame with the simultaneous transmission relay station set information, and operates according to the preset state.

Abstract: An apparatus and method for simultaneous transmission scheduling in a multi-hop cellular system are provided, in which a base station presets simultaneous transmission relay station set information and transmits the simultaneous transmission relay station set information to relay stations managed by the base station, and an relay station receives the simultaneous transmission relay station set information from the base station, determines, upon receipt of a data frame from the base station, a state of the relay station preset in relation to a receiving relay station for the data frame by comparing an ID of the receiving relay station included in the data frame with the simultaneous transmission relay station set information, and operates according to the preset state.

Abstract: A method for receiving multicast service data by a terminal in a communication system. The method includes receiving a pilot from a base station, measuring channel state information using the received pilot, and transmitting the channel state information to the base station; receiving a frame from the base station, and determining whether there is an error in the received frame; when no error has occurred in the received frame, determining whether the number of frames consecutively received without error is greater than or equal to a predetermined number; and when the number of frames consecutively received without error is greater than or equal to the predetermined number, transitioning to a non-feedback state where the terminal transmits no channel state information to the base station. The frame includes multicast service data.

Abstract: A method for receiving multicast service data by a terminal in a communication system. The method includes receiving a pilot from a base station, measuring channel state information using the received pilot, and transmitting the channel state information to the base station; receiving a frame from the base station, and determining whether there is an error in the received frame; when no error has occurred in the received frame, determining whether the number of frames consecutively received without error is greater than or equal to a predetermined number; and when the number of frames consecutively received without error is greater than or equal to the predetermined number, transitioning to a non-feedback state where the terminal transmits no channel state information to the base station. The frame includes multicast service data.