The subway is a common transportation system accessed by over 8 million people on a daily basis in Metropolitan Seoul area. The subway ventilation system located on a street occupies a large area of walkways which cause inconvenience to the public. In this paper, approaches to reduce the ventilation sitting area on the pathway are examined. 5 different preliminary models of ventilation systems are analyzed to minimize the pathway obstacle area such that the public may have an easy access to pass by on the street. The amount of the air ventilation is predicted using the CFD software to ensure an efficient ventilation. The ventilation performance is verified by theory and numerical analysis. The result shows that one of the proposed model combined with the hybrid ventilation satisfies the regulation requirement of the air quantities. We may conclude that the proposed ventilation design provides a smooth walking environment to the public while the ventilation volume is maintained to the existing ventilation system with no modification of the current ventilation holes and structures.

An electric motor is the one of the most important parts in robot systems, which mainly drives the wheel of mobile robots or the joint of manipulators. According to the requirement of motor performance, the controller type and parameters vary. For the wheel driving motors, a speed tracking controller is used, while a position tracking controller is required for the joint driving motors. Moreover, if the mechanical parameters are changed or a different motor is used, we might have to tune again the controller parameters. However, for the beginners who are not familiar about the controller design, it is hard to design pertinently. In this paper, we develop a nominal robust controller model for the velocity tracking of wheel driving motors and the position tracking of joint driving motors based on the disturbance observer (DOB) which can reject disturbances, modeling errors, and dynamic parameter variations, and propose the methodology for the determining the least control parameters. The proposed control system enables the beginners to easily construct a controller for the newly designed robot system. The purpose of this paper is not to develop a new controller theory, but to increase the user-friendliness. Finally, simulation and experimental verification have performed through the actual wheel and joint driving motors.