The error between the speed display of the speedometer and the speed display of the navigation occurs in the process of driving the vehicle which makes most of the driver confused and also experience anxiety hence in this paper, by the car management law number 73 (2), tests were conducted with following procedures measured by standard speed tester to analyze the error clearly. The experiment was carried out by installing a car on a speed tester with a speed difference of 10km/h from 30 to 80km/h according to the manufacturer and the vehicle. The result was obtained by measuring differences of the speed display error between the speedometer and navigation when driving the car on the road at the same speed. With the standard speed gauge at 40km/h, error percentage of the speed tester and Morning was 15.9% (5.5km/h) and Sonata was 6.4% (2.4km/h). The error percentage between different car company models was 9.5%. With the standard speed gauge at 40km/h, the error percentage of speed displayed by navigation and Morning was 14.2% (5km/h) and Sonata was 5.3% (2.4m/h). The error percentage between different car company models was 9.6%(3km/h). It was shown that according to the standard safety and rules of the speedometer, the cars were manufactured considering the safety. The speed difference between the speed tester and the navigation was 1.7% (0.5km/h) for Morning, 0.6% (0.2km/h) and 1.1% (0.3km/h) for Trax.

Human-robot co-operation becomes increasingly frequent due to the widespread use of service robots. However, during such co-operation, robots have a high chance of colliding with humans, which may result in serious injury. Thus, many solutions were proposed to ensure collision safety, and among them, collision detection algorithms are regarded as one of the most practical solutions. They allow a robot to quickly detect a collision so that the robot can perform a proper reaction to minimize the impact. However, conventional collision detection algorithms required the precise model of a robot, which is difficult to obtain and is subjected to change. Also, expensive sensors, such as torque sensors, are often required. In this study, we propose a novel collision detection algorithm which only requires motor encoders. It detects collisions by monitoring the high-pass filtered version of the velocity error. The proposed algorithm can be easily implemented to any robots, and its performance was verified through various tests.

As the NNSS system calculates ship's position by the doppler shift of the NNSS radio waves caused by the change of the distance between Transit Satellite and the ship, ship's speed error inevitably results in the position error, and moreover this kind of erroris most dominant compared with other errors especially in high speed ships and airplanes. Most NNSS receivers now in use have adoptedsuccessive short doppler counts as positioning data and by investigating the dispersion of serval successive positions calculated and by neglecting the mean position having dispersion of over certain threshold level, more accurate adn safe position is to be achieved. This paper proposes the method of finding ship's true speed by selecting a speed having least position dispersion for given successive doppler counts. And by computer simulation it was verified that the method proposed here is reasonable in finding the ship's desired correct speed together with the correct ship's position.