• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.2
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• pp.59-64
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• 2003

Continuously Variable Transmission (CVT) consists of a driving pulley and a driven pulley joined by rubber V-belt. Each pulley consists of a fixed flange and a movable flange. The main advantages of the U with V-belt, which has been Popular in Asia, are a simple mechanism less maintenance and low cost. One of the important factors which have an influence on the performance of the CVT is change of axial distance. Base on an experiment the effects of transfer torque and speed ratio of both driving pulley and driven pulley during the alteration of axial distance were studied.

• Korean Journal of Construction Engineering and Management
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• v.6 no.4 s.26
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• pp.152-163
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• 2005

Pile driving work causes a vibration problem in the construction site using pile foundation and often causes civil affairs by construction noise around the construction site. For the vibration and noise problems, the driving after drilling method rather than the direct driving method is being generalized for reducing vibration and noise. However, this method also causes civil affairs when the driving work is operated in adjacent area. This study suggests a criterion for evaluating an optimal allowed distance for pile driving work by the driving after drilling method. Actual surveys of vibration and noise for pile driving work in seven construction sites were used for developing regression analysis equations. The results can be a standard to estimate the allowed distance to avoid vibration and noise problems in pile driving work for deep foundation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1693-1700
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• 2012

Recently, the warning system to aid drivers for safe driving is being developed. The system estimates the distance between the driver's car and the car before it and informs him of safety distance. In this paper, we designed and implemented the collision warning system which detects the car in front on the actual road situation and measures the distance between the cars in order to detect the risk situation for collision and inform the driver of the risk of collision. First of all, using the forward-looking camera, it extracts the interest area corresponding to the road and the cars from the image photographed from the road. From the interest area, it extracts the object of the car in front through the analysis on the critical value of the shadow of the car in front and then alerts the driver about the risk of collision by calculating the distance from the car in front. Based on the results of detecting driving cars and measuring the distance between cars, the collision warning system was designed and realized. According to the result of applying it in the actual road situation and testing it, it showed very high accuracy; thus, it has been verified that it can cope with safe driving.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.3
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• pp.651-658
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• 2015

Recently, lots of research works have been actively focused on the self-driving car. In order to implement the self-driving car, lots of fusion techniques should be merged and, specially, it is noted that a vehicle-attached camera can provide several useful functionalities such as traffic lights recognition, pedestrian detection, stop-line recognition including simple driving records. Accordingly, as one of the efficient tools for the self-driving car implementation, this paper proposes a mathematical model for estimating effectively the road distance with a vehicle-attached black box camera. The proposed model can be effectively used for estimating the road distance by using the height of black box camera or the widths of the referenced road line and the observed road line. Through several simulations, it is shown that the proposed model is effective in estimating the road distance.

• Journal of the Korea Furniture Society
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• v.22 no.1
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• pp.18-25
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• 2011

This experiment was carried out to investigate the effects of nail diameter, driving distance from end on the nail check length, and the effects of nail diameter, prehole for nail driving, and nail driving slope on the nail withdrawal resistance, by the static test of universal testing machine. The test specimen were Japanese cedar (Cryptomeria japonica D. Don.) boards grown in southern district of Korea, and the nails for test were 2.02～4.82 mm in diameter. After nail driving, the back face checks of test boards were longer than the surface checks. The optimum nail diameter without checks or loss of nail withdrawal resistance were below 10% of board width and the optimum driving distance from end of boards were ten multiple of nail diameter. The relation between nail diameter (x) and withdrawal resistance (y) was linear and the regression formulae for Japanese cedar board was y = 8.66x + 7.6 ($R^2=0.978$). As both of the prehole diameter and driving slope were increased, the withdrawal resistances were significantly decreased.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1307-1312
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• 2023

In this paper, we propose a hybrid camera system that combines cameras with different focal lengths and LiDAR (Light Detection and Ranging) sensors to address the core components of autonomous driving perception technology, which include object recognition and distance measurement. We extract objects within the scene and generate precise location and distance information for these objects using the proposed hybrid camera system. Initially, we employ the YOLO7 algorithm, widely utilized in the field of autonomous driving due to its advantages of fast computation, high accuracy, and real-time processing, for object recognition within the scene. Subsequently, we use multi-focal cameras to create depth maps to generate object positions and distance information. To enhance distance accuracy, we integrate the 3D distance information obtained from LiDAR sensors with the generated depth maps. In this paper, we introduce not only an autonomous vehicle platform capable of more accurately perceiving its surroundings during operation based on the proposed hybrid camera system, but also provide precise 3D spatial location and distance information. We anticipate that this will improve the safety and efficiency of autonomous vehicles.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.309-316
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• 2017

In shuttle vans designed to transport children, the recognition of a child's approach and departure is very important. Ultrasonic sensors are generally used for a short distance around a vehicle. Although ultrasonic sensors are cheaper than other ADAS sensors, the number of sensors installed in a van should be optimized. In order to recognize the presence of a child around a shuttle van, this paper proposes the placement of ultrasonic sensors in the van. Considering the turning radius of the van and the distance from each sensor to a child, collision risk is classified as 'safe', 'warning', and 'danger'. The sensor placement and the recognition algorithm are verified in a virtual driving environment.

• The Research Journal of the Costume Culture
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• v.25 no.4
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• pp.499-508
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• 2017

Functional inner-wear being currently sold is being made without regard to the characteristics of various sports events. The purpose of this study is to identify this problem and to investigate the effect of sports taping on golf swing when wearing functional inner-wear. The subjects of this study were 8 male golfers belonging to Korea Professional Golf Association, and Launch monitor and Trackman were used to find out golf club action, ball pitch, distance, etc. There are three types of clubs: driver, wood, and iron, and the first experiment was carried out using only functional inner-wear. In the second experiment, we experimented with functional inner-wear after sports taping, and we compared and analyzed the distance depending on each experiment, the speed of the ball and the club, and the accuracy of the club face. The results of the study were as follows. As a result of driving distance, according to the presence of sports taping on functional inner-wear, there was a statistically significant difference in the driving swing and wood swing, for club and ball speed, there was a statistically significant difference only in the driving swing. Regarding the accuracy by the presence of sports taping on inner-wear, there was a statistically significant difference in the driving swing, wood swing, and iron swing. In conclusion, the sports taping in the functional inner-wear had a positive effect on golf performance improvement, and we hope that golf inner-wear these two specifications combing will be developed in the future.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.7
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• pp.599-604
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• 2013

Path planning of mobile robots has a purpose to design an optimal path from an initial position to a target point. Minimum driving time, minimum driving distance and minimum driving error might be considered in choosing the optimal path and are correlated to each other. In this paper, an efficient driving trajectory is planned in a real situation where a mobile robot follows a moving object. Position and distance of the moving object are obtained using a web camera, and the rotation angular and linear velocities are estimated using Kalman filters to predict the trajectory of the moving object. Finally, the mobile robot follows the moving object using a single curvature trajectory by estimating the trajectory of the moving object. Using the estimation by Kalman filters and the single curvature in the trajectory planning, the total tracking distance and time saved amounts to about 7%. The effectiveness of the proposed algorithm has been verified through real tracking experiments.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.135-136
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• 1998

The purpose of this study is to develope a validation method for driving simulator. Physiological responses such as EOG, ECG, and driver's behaviour were measured by using actual vehicles. The characteristics of the recognition of the acceleration by the human are investigated. These results showed that physiological responses was changed by the driving environment. Subject recognized that he drove more than real distance and turning angle.