• Journal of the Korean Society for Precision Engineering
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• v.31 no.10
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• pp.935-945
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• 2014

This paper presents a new road generative system that employs a pad of preventive overspeed or tollgate. The system consists of pad, shaft, torsional damper, oneway-clutch, gear system, and electricity generator components. When the car driven through the road generation system, it occurred to surplus energy in the DC power. In order to maximize the power of electricity energy harvester, the simulation software is developed. It is used to determine parametric dimension for optimal design with the theoretically calculated results from the simulation software. The transient responses at the conditions of low and high vehicle speed are compared with the calculated results as torque, impact force, power, out energy etc. Consequently, before design a road generation system, the analysis of simulation results shows that the proposed concept and system has efficiency and confidence.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.4
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• pp.35-41
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• 2011

The purpose of this study was to examine drivers' driving behaviors and eye-movements according to driving speed and navigation- position while operation of the navigation in driving. For this purpose, two driving conditions (low-speed and high-speed) and two navigation-positions (top and bottom location of the center console) were set. Drivers' driving behaviors (speed, speed variation, coefficient of variation, and the number of collisions) and eye-movements (overall eye pattern, the average scanning time of navigation, and the number of gaze-out on the road for more 2 seconds) were measured. As a result, when the navigation was located at the bottom of the console, difficulties of lateral control was appeared in low-speed driving condition, and the that of longitudinal control was appeared in high-speed driving condition. In addition, above situation made the drivers' scanning times of navigation long, increased the number of gaze-out on the road for more 2 seconds, and made overall eye pattern monotonous. These results could be interpreted that the manipulation of the navigation at the bottom of console cause reduced attention capacity due to the cognitive load.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.43-53
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• 2010

The increasing interest in the use of automated photographic equipment in Korea enables to detect speed violation and enforce traffic laws. Since 1996, Korean National Police Agency has been promoting a project for installation of Automated Speed Enforcement (ASE) system aiming at reduction of accidents. Recently, point to point speed cameras operate to measure a driver's average speed across length of road and/or the spot speed at individual camera sites along the road length. In this study, we were analyzed to driver's operating characteristics in point to point speed cameras. The point to point speed camera system has link-long influence on drivers and their speeds despite enforcement being visible only at the start and end of enforced road length. Then, mean and 85th percentile speeds were below speed limit along enforced road length by the two camers. Also, Female drivers were driving at low speed than male drivers along the road length.

• Journal of Korean Society of Transportation
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• v.14 no.4
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• pp.77-90
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• 1996

Recently existing the road traffic low is requlated by hump standard, which is established throuth the actual england TRRL(Transpodt and Road Research Laboratory) experiment. The determined standard has been utilized, however, wihtout the test on of our street and its drivers driving characteristics. Even with the utilization, the appropriate before and after management, is not constituted. In Spite of minimum speed limit, in many case, the utilization itself is questionalble rather than the purpose of restraining speed limit or reducing vehicle confacts. Along with hump consideration, social attention is focused due to series of personal law suit(traffic accident) field against the negligence of local organization management. Therefore counter measure of safe transportation facility is urgently required. With consideration of above background, the purpose of this research is to develop the hump that is appropriate with our transportation environment. This can be achieved thr ugh analysis of hump effectiveness, examination of drivers awamess, facilitation/management problems, and various problems in verticle acceleration.

• International Journal of Highway Engineering
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• v.13 no.1
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• pp.59-67
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• 2011

It can prevent traffic accidents in a way as taking precautionary measures for road safety at signalized intersection in advance. Particularly, traffic accidents can be reduced at relatively low cost without redesigning alignments. That is 'Positive Guidance method' which can help prevent traffic accidents through improvement of road facilities at signalized intersection. In this study, potentially higher hazardous signalized intersection due to speeding was selected through site investigation. Field analysis at designated section was conducted and devised a plan for improvements of road facilities. Subjects drove in driving simulator in 3-D virtual reality of designated intersection. Based on data from simulator, statistical analysis(t-verification) was conducted for 'Before and After effectiveness' of speed reduction. As a result, it indicates that speed reduction was effective after improvements at each spot in driving simulator. In the future, hazardous signalized intersections which can be applied for PG method will be effective for road safety based on this research.

• Transactions of Materials Processing
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• v.23 no.2
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• pp.116-121
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• 2014

Low pressure die casting and flow forming have been successfully used to produce sound road wheels from magnesium alloy AM80. In the current study, high speed compression testing was initially conducted to simulate the flow forming of a Mg wheel. Subsequently the flow forming was simulated with "Forge$^{TM}$", an FEM software package. On the basis of flow forming simulations, the flow forming of the Mg wheel was performed under different conditions. For the flow forming experiments, the preform castings were made by low pressure die casting from AM80, a commercial magnesium alloy. In flow forming of the magnesium preform wheel, the flow forming of the Mg wheel was successfully accomplished when the feed rate was less than half that for the forming of an aluminum road wheel. The reduction in feed rate was 52%. Finally, a comparison with the flow forming simulations was made.

• Journal of ILASS-Korea
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• v.21 no.4
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• pp.214-222
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• 2016

Changes in road infrastructure affect driving patterns and pollutant emission characteristics. we analyzed the changes in driving patterns and pollutant emission characteristics of the driving route via measured driving patterns at year 2009 and 2016. Since 2009, there has been an increase in population and traffic demand, including residential areas and industrial facilities. Traffic conditions were improved such as the opening of the highway Inter-Change to Seoul and the construction of underground driveway. As a result, the average vehicle speed increased. More detail comparisons have made on the changes of the underground driveway section and the crossroad section, which are expected to have significant changes in the transportation infrastructure. The vehicle speed distribution of the underground driveway changed from low speed to high speed, and the increase of the time spent at the high speed and high load caused the increase of NOx emissions. The vehicle speed also increased at the crossroad section, and the consequence NOx and $CO_2$ emissions decreased. It is mainly because the decreased time spent at idle, which results from the proper traffic demand management at this area.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.155-160
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• 2001

The road simulator system can simulate the longitudinal, lateral, and vertical movement changed by road conditions and vehicle dynamic characteristics while driving. This system provides the durability evaluation of vehicle suspensions. The system consists of hydraulic actuators, link mechanism, and servo controller. The hydraulic actuators are specially manufactured using low friction seals to endure high speed movement. The link mechanism is designed in order to minimize the dynamic effect during motion and remove the interference between 3axes actuators. The servo controller is composed of sensors, sensor amplifiers - displacement transducers and load cells, and an industrial PC with DSP board which calculates the control algorithm to control hydraulic actuators. The test results are included to evaluate the performance of this simulator comparing vehicle driving test.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.6
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• pp.526-531
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• 2012

This paper, we describe the vector control of surface mounted PMSM (Permanent Magnet Synchronous Motor) using the fuzzy controller which is suggested algorithm. In these days, when vehicle is operated or not, whether the road is covered or not, the sensitivity of the steering column is not stable. To make up for it, the PI gain of a steering column controller is adjusted by experience. It becomes the price because it need a lot of sensor. Also it is difficult to implement robust control because we need a lot of parameters for variable road conditions which are the off road, the on road, a low battery voltage, a high battery voltage, a vehicle speed. In this paper, we propose fuzzy controller using the suggested algorithm which suitable for steering system. We test the fuzzy controller with the various condition. We get the good performance of fuzzy controller even if it is nonlinear system. We check a robust the fuzzy controller using the suggested algorithm.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.79-83
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• 2006

The present low speed crash regulations and RCAR test for insurance estimate do not tend to reflect car crash occurred on a road. Therefore, car makers are trying to readjust test standard be similar to a real situation. Passenger cars and SUV vehicles on the market will be subject to this study for car to car crash. In addition, we will discuss improvement of test methods for a low speed crash and direction of bumper design by performing this impact analysis.