• 대한교통학회지
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• 제25권1호
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• pp.73-79
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• 2007

본 연구는 트럼펫 IC 램프의 교통사고를 다룬다. 연구의 목적은 회전방향(그리고 기하구조 요소와의 조합)에 따른 교통사고와의 관계를 분석하는데 있다. 이를 위해 본 연구에서는 트럼펫 IC 연결로의 회전방향과 종단경사와의 조합 및 회전방향과 곡선반경과의 조합에 따른 교통사고와의 관계분석에 중점을 둔다. 귀무가설을 검정한 결과 트럼펫 IC 연결로 회전방향에 따른 평균사고율과 평균사고건수는 각각 신뢰수준 90%와 95%신뢰수준에서 기각되었다 또한 트럼펫 IC 연결로 회전방향-종단경사의 조합과 회전방향-곡선반경의 조합에서도 평균사고건수와 평균사고율은 모두 95%신뢰수준에서 기각되었다. 요약하면, 우회전 이동류가 좌회전에 비해 더 위험한 것으로 분석된다. 또한 우회전-상향 램프와 좌회전-곡선반경 200이상 램프가 타 램프에 비해 교통사고 잠재력이 더 높은 것으로 분석된다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.397-401
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• 2003

In this work, diamond turning process is used to produce mirror surface on a Al cone. The Al cone as used as a mirror which can reflect a laser beam without scattering and, hence, it is critical to minimize the surface roughness of a Al cone. During diamond turning, feedrate and tool nose radius are changed to investigate characteristics of the ultra precision machined surface of a Al cone. A laser beam of 633 nm is applied to examine the effect of surface roughness on the characteristics of reflectivity. It is found that surface roughness is not significantly affected by feedrate. The main factor influencing surface roughness is tool nose radius. The line patterns of reflected laser beams show that the minimum surface roughness of 0.08 $\mu\textrm{m}$ (Ra) is required to avoid scattering phenomena of reflectivity.

• 한국공작기계학회논문집
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• 제13권5호
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• pp.96-102
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• 2004

In this study, we have developed the simulation tool in order to investigate driving trajectory of AGV for container transport. AGV for container transport is different from the indoor AGV in that it is a large size structure at being loaded the weight of 40 ton. and AGV for container transport is applied to front wheel steering, rear wheel steering, all wheel steering, and crap steering. Therefore, we have developed the simulation tool considering dynamic problems and a center of turning in accordance with fourth ways of steering mode. As the result of this study, we have confirmed that this tool is useful and cost-effective in the dynamic analysis or large size vehicles. Also, it is useful to calculate the minimum radius of turning for large size vehicles.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1076-1081
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• 2004

In this study, we have developed the simulation tool in order to investigate driving trajectory of AGV for container transport. AGV for container transport is different from the indoor AGV in that it is a large size structure at being loaded the weight of 40 ton. And AGV for container transport is applied to front wheel steering, rear wheel steering, all wheel steering, and crap steering. Therefore, we have developed the simulation tool considering dynamic problems and center of turning in accordance with four way of steering modes. Throughout some computer simulations, we have confirmed that this tool is useful to analysis dynamic problems and to calculate minimum radius of turning for large size vehicles.

• 한국안전학회지
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• 제32권1호
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• pp.128-133
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• 2017

This study deals with the roundabout traffic accidents by traffic impeding factor. The purpose of this study is to comparatively analyze the characteristics of accidents and to develop the accident models. In pursuing the above, this study used a statistical program SPSS 20.0 to analyze 2,342 accidents occurred within 79 roundabouts in Korea. The main results are as follows. First, 4 accident models which were all statistically significant were developed. Second, the traffic volume and width of right-turn-only lane were analyzed to be common variable in the bus stop related models. The variables such as right-turn-only lane, street light, turning radius of entry lane were selected as specific variables. Especially street light and turning radius of entry lane were evaluated to have negative effects to the accidents. It is, therefore, essential to install the street light and place a sufficient turning radius in order to reduce the roundabout accidents. Finally, the traffic volume and number of entry lane were analyzed to be common variable in the on-street parking related models. Also, the width of right-turn-only lane and bus stop were evaluate to be specific variables in the model with on-street parking. This can be expected to give some implications to making the accident reduction guidelines.

• 대한교통학회지
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• 제27권3호
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• pp.39-47
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• 2009

교통안전시설 실무편람에 의하면 현재 U-Turn 설치 가능한 지점으로 최소폭원을 '편도 폭 9m 이상'의 지점으로 하고 있으며, U-Turn 허용차량은 승용차로 제한하는 것을 원칙으로 하도록 규정하고 있다. 그러나 최근 대형화된 승용차와 보편화된 SUV(sports utility vehicle)차량이 한번에 U-Turn을 완료하지 못하면서 교통소통과 교통안전에 문제를 야기시키고 있다. 본 연구에서는 실제 차량을 이용한 U-turn 회전반경의 실차 조사치와 교통사고 재현 프로그램인 PC-Crash에 의한 예측치를 비교 검정한 후 PC-Crash를 이용하여 국내 승용차에 대해 U-turn 회전반경에 대해서 예측하고 U-Turn 설치를 위한 적정 폭원으로 제시하였다.

• 제어로봇시스템학회논문지
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• 제17권6호
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• pp.513-520
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• 2011

This paper presents the motion planning of robotic vehicles for the path tracking and the obstacle avoidance. To follow the given path, the vehicle moves through the turning radius obtained through the pure pursuit method, which is a geometric path tracking method. In this paper, we assume that the vehicle is equipped with a 2D laser scanner, allowing it to avoid obstacles within its sensing range. The turning radius for avoiding the obstacle, which is inversely proportional to the virtual force, is then calculated. Therefore, these two kinds of the turning radius are used to generate the steering angle for the front wheel of the vehicle. And the vehicle reduces the velocity when it meets the obstacle or the large steering angle using the potentials of obstacle points and the steering angle. Thus the motion planning of the vehicle is done by planning the steering angle for the front wheels and the velocity. Finally, the performance of the proposed method is tested through simulation.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2019년도 추계학술대회
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• pp.269-269
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• 2019

선박은 충돌회피 및 변침을 목적으로 선회를 수행한다. 부적절한 화물 적재 및 선회 중 과도한 타각을 사용하면 전복사고로 이어질 수 있다. 선회 중 선박동적상태가 실시간으로 변화하기 때문에 항해사들은 선회 중 횡경사의 위험을 인지하기 어렵다. autopilot에서 추정된 조종성 지수를 이용하여 선회 중 횡경사를 예측하였다. Autopilot의 Kalman filter를 통하여 추정된 조종성 지수는 실시간으로 예측이 가능하며, 추정된 선회성 지수로부터 선회반경을 구하고 선회 중 횡경사의 계산이 가능하였다. 본 연구는 선회 중 위험횡경사 예방에 관한 기초자료로 활용하고자 한다.

• 한국운동역학회지
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• 제30권3호
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• pp.205-215
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• 2020

Objective: The purpose of this study was to investigate the relative angles and cross-correlation between body segments and ski among four alpine ski turning techniques. Method: 19 alpine ski instructors participated in this study. Each skier asked to perform 4- types of turning technique, classified by radius and level. 8 inertial measurement units were used to measure orientation angle of segment and ski on the anteroposterior and vertical axis. Results: Significant differences were found between types of turning in the segments-ski relative angle on the anteroposterior and vertical axis (p<.05). Although, cross-correlation showed a high correlation between angles of segment and ski, there were significant differences between types of turning. Conclusion: Based on our results, the relative movement and timing between each segment and ski is different according to the turning techniques, so the training methods should be applied differently.

• 한국해양공학회지
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• 제35권2호
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• pp.99-112
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• 2021

The prediction of maneuverability is very important in the design process of an underwater vehicle. In this study, we predicted the steady turning ability of a symmetrical underwater vehicle while considering interactions between the yaw rate and drift/rudder angle through a simulation-based methodology. First, the hydrodynamic force and moment, including coupled derivatives, were obtained by computational fluid dynamics (CFD) simulations. The feasibility of CFD results were verified by comparing static drift/rudder simulations to vertical planar motion mechanism (VPMM) tests. Turning motion simulations were then performed by solving 2-degree-of-freedom (DOF) equations with CFD data. The turning radius, drift angle, advance, and tactical diameter were calculated. The results show good agreement with sea trial data and the effects on the turning characteristics of coupled interaction terms, especially between the yaw rate and drift angle.