Abstract: An apparatus for judging a fatigue level and/or a dozing state of a person by capturing voices uttered at different points of time from a microphone 5M. A computer performs chaos analysis of the digital data of the inputted voices and calculates Lyapunov exponents and judges a fatigue level and/or a dozing state based on the result of the chaos analysis.

Abstract: There is provided a method for displaying aircraft positions, which is capable of effectively avoiding the occurrence of near miss or collision. The method displays the terrain of an air space under air traffic control apparently in three dimensions on a display screen, displays aircraft marks at positions on the display screen so as to correspond to the three-dimensional positions of the respective aircraft, and displays a warning mark when a distance between two aircraft is shorter than a threshold value, wherein the warning mark comprises a triangle having three apexes, which comprise the aircraft marks, and a position that is apart from the aircraft mark of one of the aircraft along a vertical line extending perpendicular to the one aircraft toward a ground surface of the terrain by a distance corresponding to an altitude difference between both aircrafts on the display screen.

Abstract: In an air traffic control system for controlling aircraft a three-dimensional position is provided to monitor a position of an air traffic controller. An image is displayed on a display portion with reference to the position of the controller. The image displayed on the display portion always appears in a front image regardless of the position of the controller or may be selected to be displayed on a selected area of the display portion determined by the position of the controller.

Abstract: A reply is received from aircrafts for calibration in response to an interrogation of SSR stations to detect transmission timing of the interrogation of the SSR stations and directly-facing timing of antennas of the SSR stations and thus detect a position of an arbitrary aircraft based on the transmission timing and directly-facing timing and the reply from the aircraft.

Abstract: An SSR reply, which is sent out from an aircraft, is received and separated into one SSR reply to one SSR station and the other SSR reply to the other SSR station, thereby generating aircraft information of the aircraft based on one of the one SSR reply and the other SSR reply.