Abstract: The participant terminal 80 includes imaging means 81 for shooting video of the participant who uses the participant terminal 80, frequency measurement means 82 for measuring the number of nods of the participant from the shot video, and action information transmission means 83 for transmitting action information that information of the participant is associated with the number of nods to the server 70. The server 70 includes transmission means 71 for transmitting the action information to the speaker terminal 90. The speaker terminal 90 includes participant output means 91 for outputting the information of the participant in order according to the number of nods included in the action information.

Abstract: In a method of operating a pump turbine, compressed air is supplied into a runner chamber of the turbine and a leakage drain valve is opened of a guide vane at the time of starting the pump turbine to force downwardly the level of the water in the runner chamber and to rotate a runner of the pump turbine in air, the compressed air in the runner chamber is exhausted when the rotating speed of the runner reaches a rated speed for the pump operation, thus filling the runner chamber with water. The water containing a large quantity of dissolved oxygen and contained near the periphery of the runner is drained into a spillway through a pipe for draining water leakage through the guide vanes, priming pressure in the runner chamber is detected and a leakage drain valve in the drain pipe is closed after a predetermined time from the detection of the priming pressure.