• 한국자동차공학회논문집
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• 제6권3호
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• pp.143-153
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• 1998

In this reaserch, a program for real time simulation of a vehicle is developed. This program uses relative coordinates to save the computation time and BDF(Backward Difference Formula) to integrate system variables. Numerical tests were performed for J-turn and Lane change steering, respectively. The validity of the program is proved by the ADAMS package. Numerical results showed that the proposed implicit method is more stable in carrying out the numerical integration for vehicle dynamics than the explicit method. Hardware requirements for real time simulation are suggested.

• 한국도로학회논문집
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• 제14권6호
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• pp.67-73
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• 2012

PURPOSES : This study deals with the effects on the installation of RLC(Red Light Camera). The objective is to analyze the effects of accident reduction after the installation of RLC. METHODS : In pursuing the above, the study uses the 703 accident data occurred at the 64 intersections which RLC are installed or not installed. RESULTS : The main results are as follows. First, Poisson RLC accident model developed in this study is analyzed to be statistically significant. Second, using the above developed model, 33 intersections among 40 intersections are predicted to have the decreasing effects of accidents after the installation of RLC. Finally, the reduction effects are analyzed to be affected by ADT and the number of left-turn lane. CONCLUSIONS : This study is expected to improve the efficiency of RLC and to help in decision-making of RLC installation.

• 한국자동차공학회논문집
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• 제7권5호
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• pp.162-171
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• 1999

The most important part in automated transport systems is steering control for lane keeping Most of systems developed so far have used the visual information for steering control. In this study, the steering control algorithm based on visual servoing has been developed and tested by applying it on Radio Controlled(R/C) model car equipped with one CCD camera. We also demonstrated the feasibility of using it as a pre-test car before the real car experiment in developing automated vehicles. In order to solve the problem of the limited spave and load of a model car, remote-brained approach has been taken. For steering control of a model car, the PD controller which uses the look ahead offset to generate control input has been implemented and the characteristics of the controller has been explained in view of kinematics. Some experimental results have been also illustrated so as to show the control performance and stability.

• 대한기계학회논문집A
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• 제30권10호
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• pp.1276-1283
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• 2006

This study proposes two ESP systems which are designed to enhance the lateral stability of a vehicle. A BESP uses an inner rear wheel braking pressure controller, while a EBESP employs an inner rear wheel and front outer wheel braking pressure controller. The performances of the BESP and EBESP are evaluated for various road conditions and steering inputs. They reduce the slip angle and eliminate variation in the lateral acceleration, which increase the controllability and stability of the vehicle. However EBESP enhances the lateral stability and comfort. A driver model is also developed to control the steer angle input. It shows good performances because the vehicle tracks the desired lane very well.

• 한국ITS학회 논문지
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• 제5권1호
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• pp.21-30
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• 2006

중앙버스전용차로제가 도입됨에 따라 서울의 도로환경은 단기간에 급격하게 변하였으며, 이러한 급격한 변화에 미리 준비되지 못하였던 신호운영상의 문제점들이 경험되고 있다. 장 임계적인 문제점으로 중앙버스전용차로 설치구간 신호교차로에서 일반차량 좌회전 진행을 허용할 경우, 현재 우리나라가 규정하고 있는 차량 4색신호등의 한계로 인한 신호의 비효율적 운영이다. 중앙버스전용차로 설치구간 신호교차로에서 일반차량 좌회전의 현실적 운영방안 마련이 필요하다. 본 연구는 중앙차로전용신호의 도입을 준비하기 위하여 교통관제센터의 신호운영모드별 선행좌회전 및 후행좌회전 운영방안을 검토하고, 각 운영방안 별 Signal Map 구성방안을 점검한다. Signal Map 작성방안을 검토한 결과 기존의 신호제어 장비에 추가의 신호등기신호보드를 활용하는 방법으로 제안된 방법의 현장 적용이 용이한 것으로 확인되었다.

• 한국항행학회논문지
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• 제15권5호
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• pp.705-713
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• 2011

본 논문에서는 Network RTK 보정정보 생성 프로세스에서 핵심 process인 기준국간 미지정수 결정을 위해 Hatch filter를 이용한 방법과 L1/L2 측정치 조합을 활용하는 방법에 대해 소개하고 시뮬레이션 데이터 및 실측 데이터를 활용하여 그 성능을 비교 및 검증하였다. 각각의 방법에 대해 수식 전개를 수행하였으며, 사용자 성능 검증을 위해서 다중 기준국 네트워크에 대해 생성한 보정정보와 사용자 위치에서 생성한 보정정보의 차이값을 비교하였다. 각각의 기준국간 미지정수 결정 방법을 실측 데이터에 적용하여 사용자 성능을 예측한 결과, Hatch filter를 사용한 경우에는 단일 기준국 RTK 기반의 방법에 비해 다중 기준국 네트워크에서 생성된 보정정보를 사용하는 것이 사용자 성능을 크게 향상시키는 결과를 확인하였다. 그러나 사용자의 미지정수에 영향은 없으나, 상당한 크기의 바이어스 오차가 포함되는 것을 확인하였고 그 원인에 대해 분석하였다. L1/L2 측정치 조합을 이용한 경우, Hatch filter를 사용한 방법에 비해 사용자에 발생하는 오차의 크기가 훨씬 감소하였으며 잔차의 경향성도 훨씬 감소한 것을 확인하였다.

• 한국도로학회논문집
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• 제14권6호
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• pp.167-173
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• 2012

PURPOSES : This study is to develop speed correction factor for more realistic Level-of-Service(LOS) at multilane highway. METHODS : In this study, we compared speed difference the degree of speed reductions in actual multilane road conditions with speed reduction considering speed correction factor presented in highway capacity manual using statistical techniques. And also we presents new speed correction factor analyzing collected data at national highway No.1 (Goyang~Wolrung). RESULTS : The result of analyzing and comparing new suggested speed correction factor with speed correction factor in Korea Highway Capacity Manual (KHCM) shows RMSE (Root Mean Square Error) in new speed correction factor (RMSE 1.5) is much lower than existing speed correction factor (RMSE 13.4). New suggested speed correction can be used for analyzing Level-of-Service at multilane highway. And also we suggests improvements for analysis procedure in analyzing Level-of-Service at multilane highway CONCLUSIONS : As a result of comparing differences, we draw the causes that effect the differences in speed and suggest new speed correction factor that consider traffic volumes. It can be more rational because it uses speed correction factor which can consider more realistic traffic conditions, etc.

• International Journal of Automotive Technology
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• 제8권1호
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• pp.49-57
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• 2007

This paper proposes a traction control system (TCS) that uses a sliding mode wheel slip controller and a PID throttle valve controller. In addition, a yaw motion controller (YMC) is also developed to improve lateral stability using a PID rear wheel steering angle controller. The dynamics of a vehicle and characteristics of the controllers are validated using a proposed full-car model. A driver model is also designed to steer the vehicle during maneuvers on a split ${\mu}$ road and double lane change maneuver. The simulation results show that the proposed full-car model is sufficient to predict vehicle responses accurately. The developed TCS provides improved acceleration performances on uniform slippery roads and split ${\mu}$ roads. When the vehicle is cornering and accelerating with the brake or engine TCS, understeer occurs. An integrated TCS eliminates these problems. The YMC with the integrated TCS improved the lateral stability and controllability of the vehicle.

• 한국도로학회논문집
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• 제15권2호
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• pp.131-138
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• 2013

PURPOSES : The intents of the study are to identify the accident factors and to demonstrate the potentials of tobit model as a tool to study the number of accidents on arterial roads segments. METHODS : This paper uses a tobit regression as a methodology to analyze the factors affecting the number of accidents. In pursuing the above goal, this study gives particular attentions to analyzing the data of 2,446 accidents (1,610 in major arterial roads and 836 in minor arterial roads) occurred on arterial roads in 2007 to 2010. RESULTS : First, 3 accident models which were classified by total arterial roads, major arterial roads and minor arterial roads, and were all statistically significant were developed. Second, the exclusive right-turn lane as common variable, and the number of accident, traffic volume, number of lanes, link length, rate of median, number of entrances, number of pedestrian crossings, number of curves, number of bus stops and exclusive left-turn as specific variables of the models were selected. Finally, the paired sample t-test could not be rejected the null hypotheses of three types of models. CONCLUSIONS : Using data from vehicle accidents on arterial roads, the estimation results show that many factors related to roadway geometrics and traffic characteristics significantly affect to the number of accidents.

• 한국컴퓨터정보학회논문지
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• 제8권2호
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• pp.37-43
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• 2003

본 연구는 연속된 컬러 영상으로부터 전방의 차량과 차선을 검출하는 과정에서 연속 영상 분석을 통하여 다중 차량을 검출하는 방법을 제안한다. 하나의 프레임에서 차량 후보 영역의 검출은 그림자 특징과 에지 성분을 이용한다. 그리고, 다중 차량 영역을 검출하는 방법은 연속된 영상에 존재하는 차량 후보 영역들의 차량 추정값과(EOV)과 누적 유사도 함수(ASF)를 분석하여 차량일 가능성을 검사한다. 대부분의 연구 방법이 전방의 한 차량을 검출하는데 비해 본 연구에서는 여러 차량을 검출하는 방법을 제시하였으며, 교통량이 많고, 차선 변경이 자주 있는 경우에도 차량의 검출이 가능하도록 한다. 제안된 방식의 효과를 검증하기 위해 노트북 PC와 PC용 CCD 카메라로 도로에서의 영상을 촬영하고 차량 검출 알고리즘을 적용한 처리 시간, 정확도 및 차량검지 결과를 보인다.