• Journal of the KSME
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• v.33 no.10
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• pp.856-860
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• 1993

차량의 조종안정성을 해석하기 위해서는 차륜과 현가장치에 의한 비선형성과 조향장치의 동특성 등을 고려한 3차원 차량 모델을 이용하여 정상상태와 과도상태에서의 조향입력에 대한 차량 주 행역학을 해석하여야 한다. 승차감, 조향성능, 주행안정성 등의 동적성능과 현가장치의 특성관 계를 규명하기위하여 3차원 차량모델에 의한 해석과 설계변수에의 민감도 해석을 수행할 필요가 있다.

• Journal of Korean Society of Steel Construction
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• v.14 no.1
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• pp.95-104
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• 2002

In this paper, research for dynamic wheel loads of 3-D vehicle model considering tire enveloping model is carried out. Heavy trucks with 2-axles and 3-axles are modeled by 7-d.o.f. and 8-d.o.f., in which contact length of tire and pitching of tandem spring axles is considered. Dynamic equations of vehicle are derived by using the Lagrange's equation and solution of the equation is calculated by 5th Runge-Kutter method. The validity of the developed 3-D vehicle model is demonstrated by comparing the results obtained by the present method and experimental data by Whittemore. The maximum impact factors of tire force are calculated when vehicle models of 8ton and 15ton dump truck are running on the different class roads with 1.0km and on the various step bump.

• Journal of Korean Society of Steel Construction
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• v.9 no.1 s.30
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• pp.23-36
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• 1997

교량(橋梁)의 동적응답(動的應答)을 파악하기 위해서는 노면(路面)조도에 의해 영향을 받는 차량의 거동 파악이 중요하게 된다. 최근, 교량의 상판(床版)등에서 발생되는 피로(疲勞)의 영향에 대한 관심이 고조되어 서서히 교통진동의 3차원 모델링에 대한 중요성이 대두되고 있다. 이에 본 연구에서는 교량에 발생되는 교통진동(交通振動)의 영향을 좀더 정확히 표현하기 위하여 3차원 해석 방법을 제시한다. 해석방법으로 유한 요소법이 이용되었고, 차량 모델링은 하나의 전축(煎軸)과 두 개의 후축(後軸)을 갖는 8자유도계(自由度系) 차량 모델을 이용하여 수치 시뮬레이션을 수행하였다. 동적(動的) 연립미분방정식(聯立微分方程式)의 해법에서는 Newmark-${\beta}$법(法)을 이용하였고, 가상 노면요철(凹凸)모델링에서는 정상불규칙과정(定常不規則過程)으로 가정하여 노면 요철(凹凸)을 생성하여 시뮬레이션에 사용하였다. 또한 실제 차량 및 교량에서의 실측치와 비교하여 모델의 검증을 수행하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6A
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• pp.989-999
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• 2006

In this paper, numerical analysis method to perform linear dynamic analysis of bridge considering the road surface roughness and bridge-vehicle interaction when vehicle is moving on bridge is presented. The vehicle and bridge are modeled as three-dimension where contact length of tire and pitching of tandem spring are considered and single truck with 2-axles and 3- axles, and tractor-trailer with 5-axles are modeled as 7-D.O.F., 8-D.O.F., and 14-D.O.F., respectively. Dynamic equations of vehicle are derived from the Lagrange's equation and solution of the equation is obtained by Newmark-${\beta}$ method. The surface roughness of bridge deck for this analysis is generated from power spectral density (PSD) function. Beam element for the main girder, shell element for concrete deck and rigid link between main girder and concrete deck are used. The equations of the motion of bridges are solved by mode-superposition procedures. The proposed procedure is validated by comparing the results with the experimental data by Whittemore and Fenves.

• Journal of Broadcast Engineering
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• v.28 no.3
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• pp.329-332
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• 2023

3D Object Detection using deep neural network has been developed a lot for obstacle detection in autonomous vehicles because it can recognize not only the class of target object but also the distance from the object. But in the case of 3D Object Detection models, the detection performance for distant objects is lower than that for nearby objects, which is a critical issue for autonomous vehicles. In this paper, we introduce a technique that increases the performance of 3D object detection models, particularly in recognizing distant objects, by generating virtual 3D vehicle data and adding it to the dataset used for model training. We used a spherical point tracing method that leverages the characteristics of 3D LiDAR sensor data to create virtual vehicles that closely resemble real ones, and we demonstrated the validity of the virtual data by using it to improve recognition performance for objects at all distances in model training.

• Journal of Korean Society of Steel Construction
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• v.23 no.3
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• pp.397-404
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• 2011

In this paper, a research for the dynamic wheel loads of a 3D vehicle model, which relates to a tire-enveloping model, is carried out. A single truck with four axles is modeled as a 10-D.O.F. vehicle by modeling both contact length of tires and pitching of tandem spring axles. The dynamic equations of the vehicle are obtained using the Lagrange's equation, the solution of the equations is calculated by Newmark-${\beta}$ method. The validity of the developed 3D vehicle model is demonstrated by comparing results obtained from the proposed method with those from experimental data. The maximum impact factors of tire force are evaluated according to the various step bumps on which a 24-ton dump truck is running.

• Journal of the Korea Computer Graphics Society
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• v.21 no.5
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• pp.11-19
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• 2015

Our research introduces a novel system for creating 3D vehicle animation. Our system is for intuitively authoring vehicle accident scenes according to videos or based on user-drawn trajectories. Our system has been implemented by combining three existing ideas. The first part is for obtaining 3D trajectory of a vehicle from black-box videos. The second part is a tracking algorithm that controls a vehicle to follow a given trajectory with small errors. The last part optimizes the vehicle control parameters so that the error between the input trajectory and simulated vehicle trajectory is minimized. We also simulate the deformation of the car due to an impact to achieve believable results in real-time.

• Journal of Korean Society of Steel Construction
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• v.20 no.1
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• pp.151-163
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• 2008

A formulation of three-dimensional model of articulated train-b ridge dynamic interaction has been made for the Korean eXpress Train (KTX). Semi-periodic profiles of rail irregularities consisting of elevation, alignment, cross and gauge irregularities have also been proposed using FRA maximum tolerable rail deviations. The effects of rail joints and sleeper step were also included. The resulting system matrices of train and bridge are very spare, and thus, are stored in one-dimensional arrays, yielding a time-efficient solution. A numerical algorithm for computing bridge-train response including an iterative scheme is also formulated. A program simulating train-bridge interaction and solving this problem using the new algorithm is implemented as new modules for the f inite element analysis software named XFINAS. Computed results using the new program are then checked by that of the validated 2-D bridge-train interaction model. This new 3D analysis provides more detailed train responses such as swaying, bouncing, rolling, pitching and yawing accelerations, which are useful inevaluating passenger riding comfort. Train operation safety and derailment could also be directly investigated by relative wheel displacements computed from this program.

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.3
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• pp.108-115
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• 2006

In this paper, a recognition algorithm of the straight line components of lane markings and an obstacle in the travelling lane region is proposed. This algorithm also involve the pitching error correction algorithm due to traveling vehicle's fluctuation. In order to reduce their error a practical road image modelling algorithm using V.F. model and camera calibration procedure are suggested to adapt the geometric variations. It is obtained the 3D world coordinate data by the 2D road images. In experimental test, we showed that this algorithm is available to recognize lane markings and an obstacle in the traveling lane.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2006.06a
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• pp.5-8
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• 2006

본 논문에서는 3차원 좌표를 얻을 수 있는 카메라 Calibration 알고리듬을 확립하고, View Frustum(V.F.) 모델을 이용하여 도로의 영상을 모델화하였다. 그리고 주행하는 차선 내에 존재하는 선행차량의 위치측정 및 차량까지의 거리를 정확히 인식하기 위해 피칭오차를 보정하며 실시간으로 계측하는 알고리듬을 제안하였다. 기존의 많은 추돌 경보시스템(CWS)들은 도로가 평면이라 가정하여 도로와 차량사이의 기하적인 변화에 따른 오차 특성을 고려하지 않았다. 이를 보완하고자 본 논문에서는 카메라 Calibration 알고리듬을 적용하여 실세계 좌표계와 영상좌표계 사이의 기하해석으로 사영행렬을 추출하였고, V.F. 모델을 이용하여 소실점의 기하적인 해석을 통하여 차량의 피칭변화에 따른 오차특성을 실시간으로 보정하였다. 실험결과 거리의 오차를 2%이하로 줄일 수 있어 피칭변화에 강인함을 확인할 수 있었다.