• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.4
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• pp.180-188
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• 2003

The vehicle simulator is a useful virtual reality system. The simulator enables engineers to effectively research and analyze various experiments. Therefore, the development of a specific vehicle simulator is required, and its performance must be verified. This paper verifies the performance of Pusan National University Vehicle Simulator. Human sensibility ergonomic tests of vehicle simulator were also executed. The sense of simulator motion was chosen as the standard of performance evaluation. The driver's senses were subdivided into senses of rectilinear and rotational velocities. This study extracted ergonomic sensibility words that can be used to evaluate the performance of the simulator As a practical application of simulator, the relation was studied between the sense of simulator motion and the characteristics of drivers, who are classified into their sexes and driving careers. A statistical method was applied to human sensibility ergonomic tests of vehicle simulator.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.540-545
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• 2016

Many golf balls have wrong rotation axis owing to bad production and scratch. A flying golf ball makes sliced or curved motion mainly to owing the wrong rotation axis of golf ball. Dimples of golf ball make a golf ball higher and more straight flying. When we hit a golf ball by driver or iron club, the dimpled ball flies straight and rotates as well. While the ball flying, the rotating axis of the ball convergence. And this makes the ball motion curved. If we hit a golf ball in direction of the rotation axis, the flying ball makes straight motion. In this paper, we develop a control system to detect convergence axis and time of flying golf ball based on vision system. To show validity of the developed system, We experimented several case for dimpled golf balls.

• Journal of Auto-vehicle Safety Association
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• v.11 no.3
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• pp.30-36
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• 2019

This paper suggests a car-following algorithm for urban environment, with multiple target candidates. Until now, advanced driver assistant systems (ADASs) and self-driving technologies have been researched to cope with diverse possible scenarios. Among them, car-following driving has been formed the groundwork of autonomous vehicle for its integrity and flexibility to other modes such as smart cruise system (SCC) and platooning. Although the field has a rich history, most researches has been focused on the shape of target trajectory, such as the order of interpolated polynomial, in simple single-lane situation. However, to introduce the car-following mode in urban environment, realistic situation should be reflected: multi-lane road, target's unstable driving tendency, obstacles. Therefore, the suggested car-following system includes both in-lane preceding vehicle and other factors such as side-lane targets. The algorithm is comprised of three parts: path candidate generation and optimal trajectory selection. In the first part, initial guesses of desired paths are calculated as polynomial function connecting host vehicle's state and vicinal vehicle's predicted future states. In the second part, final target trajectory is selected using quadratic cost function reflecting safeness, control input efficiency, and initial objective such as velocity. Finally, adjusted path and control input are calculated using model predictive control (MPC). The suggested algorithm's performance is verified using off-line simulation using Matlab; the results shows reasonable car-following motion planning.

• Korean Journal of Applied Biomechanics
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• v.13 no.2
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• pp.101-114
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• 2003

The purpose of this study was to examine the major kinematicak variance to Increase the club head velocity during the driver swing two PGA prp-golfers utilizing 3-dimensional Image analyzing linear velocity of the club-head during the impact quantiatively. To achive these purpose, two high speed camera in 120 field/s and one high-speed camera in 500 field/s were used in this study. The program made by Younghoo Kwon(1944) was used to analysis the digitalization of reference point, digitalization of joint venter, synchronization, calculation of 3-Dimensional coordinate by DLT method, and smoothing. Through this study, the conclusions are as follow. 1. During the drivel swing, in the percentile of the total time, two pro-golfer showed 0.925, 0.929 second from adress to top-swing, 0.236, 0.929 second from top-swing to impact. 2. During the driver swing, in the displacement of the center of the body, two pro-golfer showed 45.3, 45.23% from adress, 44.3, 44.24% front impact. 3. In the velocity variance, The maximum club-head velocity two pro-golfer showed 43.36, 43.24m/s respectively the down swing. The ball velocity showed 63.12, 63.06m/s. 4. In the rotational angle of the shoulder joint. two pro-golfer showed $-13.5,-13.53^{\circ}$, during the back swing respectively. Two subject adressed opening status og upper body. 5. In the rotational angle of the right knee angle showed $156.3,154.7^{\circ}$ from the adress.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.11a
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• pp.452-455
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• 2005

In order to reproduce the traffic accident, It must save the data automatically which traffic accident 30 seconds before using black box. The Black Box can detect traffic crash accidents automatically, and record the vehicle's motion and driver's maneuvers during a pre-defined time Belied before and after the accident. But it is not easy for the police to catch running away criminal. Because, criminal can remove proof if it is 2 hours or 3 hours at least. Therefore, in this paper, in order to catch a hit and run driver in the traffic accident road, it developed an structured Query Language Server and made parts database algorithm.

• International Journal of Automotive Technology
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• v.6 no.6
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• pp.615-623
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• 2005

In this research, an effective technique was examined to improve the drift running performance. Concretely, the driver model by which the counter steer was done was assumed to the model by which the vehicle body slip angle (and the vehicle body slip angle velocity) was feed back. Next, the effectiveness of the system which added the assist steer angle corresponding to the steering wheel angle velocity to a front wheel steer angle was clarified as a drift running performance improvement technique of the vehicle. As a result, because the phase advances when the differentiation steer assistance is added, it has been understood to be able to cover the delay of the counter steer when the drift running. Therefore, it has been understood that the drift control does considerably easily. Moreover, it has been understood that the differentiation steer assistance acts effectively at the drift cornering by which the drift angle is maintained in cornering and the severe lane change with a drift at a situation. That is, it was understood to be able to settle to the drift angle of the aim quickly at the time of the drift cornering because the delay of the control steer angle of the counter steer was improved. Moreover, it was understood for the transient overshoot of the vehicle tracks to be able to decrease, and to return to the state of stability quickly at the severe lane change.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.9
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• pp.1110-1118
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• 2011

The recent power add-on drive wheelchairs (PADWs) provide greater physical activity and easier transportability and may be an excellent alternative for the typical manual and powered wheelchairs. The driving system consists of a motor and a motor driver is the most important component of the PADW In this paper, design, implementation, and testing of a driving system for a PADW are presented. To design the output power and torque for the driving system, the equation of motion has been investigated. The motor and driver were fabricated with precise machining and assembled to implement our prototype driving system. The dynamometer test has been carried out using the prototype in order to examine the torque of the system. The experimental results demonstrates that the designed driving system can provide enough output power and efficiency for utilization in a PADW.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.2
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• pp.585-593
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• 1996

According to the considerable increase of the length of belt conveyors, the dynamic analysis of systme becomes necessary to consider the variation of tensions and transient motion of components during starting and stopping of conveyor. The mathematical model of system is derived using the lumped parameter method. The input driving force is represented with two functions of time and pulley speed to count the characteristics of motor and fluid coupling. An example system was studied with 14 km in the distance of carrying. At head, it has two drivers and one gravity take-up and at tail ond driver and one power winch take-up. In the example, the transient tensions and responses, calculated using two cases of driving force, are mutually compared in starting mode. Also, the position of maximum tension and the braking force of take-up are obtained in stopping mode.

• Journal of Astronomy and Space Sciences
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• v.20 no.2
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• pp.153-162
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• 2003

Recently, we have reconstructed LX-200 12inch telescope system for tracking and observing man-made space object. Motor, motor driver and motion controller were up-graded for getting faster respond characteristic and active control available. Also, command signal was offered to the PID controller into motor driver as computed real orbiting information of objects using PC, and it's control period of command signal was reduced to the 20ms. As the result, slew speed of the mount system was in proved up to $18^{\circ}/sec$ and respond speed of the system was faster than that of commercial system. Also, flipping state of image observed could be minimized by the up-graded system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.448-455
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• 1996

In this study, to reduce vibration of step motor we use Microstep control. Microstep control of stepmotor is usually thought of as an extension of conventional stepmotor control technology. The essence ofmicro stepping is that we divide the full step of a stepmotor into a number of substep called microstep and cause the stepmotor to move through a substep per input pulse. In ideal case, bycontrolling the individual phase currents of a two-phase step motor sinusoidally we can get uniform torque and step angles. But due to the monlinear characteristics of the step motor, we need to compensate current waveform to improve the overall smoothness of the conventional micro stepping system. We implement digital Pulse Width Modulation(PWM) driver to drive step motor and microphone was used for detecting vibration. Driver enables speed change automatically byincreasing or decreasing micro stepping ratio which we call Automatic Switching on the Fly. To compensate the torque harmonics, Neural Networks is applied to the system and we foundcompensated optimal input current waveform. Finally we can get smooth motion of step motor in a wide range of motor speed.