• 대한교통학회:학술대회논문집
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• 대한교통학회 1998년도 Proceedings 제34회 추계 학술발표회
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• pp.236-244
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• 1998

When the capacity and traffic operation at signalized intersections are analyzed in Korea, the unprotected left-turn saturation flow rate, which is an important parameter for the analysis, is estimated form the USHCM model. thus, exact analysis of the left-turn is not possible because of the difference of traffic environments between two contries. In order to improve this problem, it is undertaken in this study to develop techniques for the estimation of unprotected left-turn saturation flows based on Korean drivers' data. As study intersections, signalized or unsignalized intersections on the 6, 4 and 2 lane streets are selected. the data for the saturation flow measurement and gap-acceptance behavior analysis are inputed in a notebook computer on the sites. The critical acceptance gaps of the 6, 4, and 2 lane streets are analyzed to be 6.0 secs, 4.6 secs, and 4.3 secs respectively. the average minimum headway of the left-turn vehicle was observed to be 2.6 secs. As the model to estimate unportected left-turn saturation flows, the drew model is recommended for 6 and 4 lane streets, and a graph is suggested for the 2-lane street. As the values of the parameters of the Drew model, the 2.6 secs of this study is recommended for the average minimum headway of the left-turn. But, the critical acceptance gap varies according to the approach speed of opposing traffic and driver population, it requires field survey to measure the gap of an intersection; however, the values of the gaps studied in this study may be used for the general intersections in urban area in Korean.

• 한국자동차공학회논문집
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• 제14권1호
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• pp.167-175
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• 2006

Directional stability is important performance in vehicle and tire design. The current methods to analyze this is generally based on linear concept. Using the existing concept, it cannot realistically explain the subjective assessment at all because it is hard to practically represent the nonlinear behaviour of a complex vehicle system in reality. In this paper, new method to analyze directional stability is introduced. At first, directional stability of vehicle is categorized into yaw, rear axle, and roll stability. In order to objectify these items, driver perceptual parameters based on subjective assessment are used. Using the perceptual parameters, it can successfully explain the transient maneuver of vehicle and extract objective parameters for directional stability. Finally, these objective parameters are successfully validated through two handling tests, lane change and severe lane change. The correlation results show that there exists a good correlation between subjective assessment and the proposed objective parameters.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.105-110
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• 1999

This paper presents a local obstacle avoidance method for indoor mobile robots using Lane method and velocity Space Command approach. The method locates local obstacles using the information form multi-sensors, such that ultrasonic sensor array and laser scanning sensor. The method uses lane method to determine optimum collision-free heading direction of a robot. Also, it deals with the robot motion dynamics problem to reduce some vibration and guarantee fast movement as well. It yields translational and rotational velocities required to avoid the detected obstacles and to keep the robot heading direction toward goal location as close as possible. For experimental verification of the method, a mobile robot driven by two AC servo motors, equipped with 24 ultrasonic sensor array and laser scanning sensor navigates using the method through a corridor cluttered with obstacle.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2202-2205
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• 2001

This paper is composed of two parts. One is image preprocessing part to measure the condition of the lane and vehicle. This finds the information of lines using RGB ratio cutting algorithm, the edge detection and Hough transform. The other obtains the situation of other vehicles using the image processing and viewport. At first, 2 dimension image information derived from vision sensor is interpreted to the 3 dimension information by the angle and position of the CCD camera. Through these processes, if vehicle knows the driving conditions which are lane angle, distance error and real position of other vehicles, we should calculate the reference steering angle by steering controller.

• 대한교통학회지
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• 제26권2호
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• pp.47-56
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• 2008

2차로도로는 우리나라 포장도로의 80% 이상을 차지하고 있기 때문에 2차로도로가 국내의 교통흐름에 있어서 차지하고 있는 비중은 매우 높다할 수 있다. 그러나 2차로도로는 진행방향당 한 차로만이 허용되어 있어 저속차량에 의해 지체가 발생할 경우 고속차량이 대향차로를 이용하여 추월해야 한다. 이러한 추월은 교통사고를 유발할 가능성이 매우 높으며 추월에 의한 사고는 중앙선 침범에 의한 정면 충돌사고를 일으킬 수 있으므로 사고의 심각도 또한 매우 높다할 수 있다. 그러나 2차로도로의 전반적인 운영상태 등을 나타내는 서비스수준에 대하여 현행 KHCM 에서는 '서비스수준이란 통행속도, 통행시간, 통행자유도, 안락감 그리고 교통안전 등 도로의 운행상태를 설명'하는 개념으로 정의하고 있지만 실제 서비스수준을 산정함에 있어서 서비스수준의 개념에 나타나 있는 바와는 달리 총지체율만을 이용하여 서비스수준을 산정하기 때문에 지체만을 고려하고 사고(교통안전)를 고려하지 않고 있다. 따라서 본 연구에서는 기존의 서비스수준 산정방법인 총지체율을 이용하여 지체시간을 산정하는 방법을 제시한 후, 여기에 지체비용을 곱하는 방식으로 총지체비용을 산출하는 방법을 제시하며 사고를 고려하기 위해 교통사고예측모형을 통하여 교통사고건수를 예측하고 여기에 평균교통사고비용을 곱하는 방식으로 총교통사고비용을 산출하는 방법을 제시한다. 마지막으로 앞에서 산출된 총지체비용과 총사고비용을 합산하여 운영비용을 산출함으로써 지체와 사고를 고려한 서비스수준의 새로운 판정척도를 개발하고 더불어 서비스수준을 제시하였다.

• 대한교통학회지
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• 제8권1호
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• pp.25-40
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• 1990

This study was undertaken to develop a traffic signal timing method for interconnected and semi-protected-left-turn intersections(the intersections which have left-turn signal but not exclusive left-turn lanes) on four-lane streets for energy saving and to computerize the method for the practical use. For this study, a probability model which could estimate the utilized time of the shared left-turn lane by through traffic during green period was developed based on field studies. The two left-turn treatments, leading and lagging left-turns, were tested for the intersections, and it can be concluded that the leading left-turn was more efficient for the normal urban streets on which through traffic is major traffic. Adopting the leading left-turn macro-models to estimate vehicular average delay and proportions of vehicles stopped at the intersections were developed. Using the two models as well as the idling fuel consumpution rate and the excess fuel consumption per stop-go speed change, a traffic signal timing method for the intersections for energy saving was developed and computerized. The method can be used for more than four-lane streets and for other measures of effectiveness such as minimum delay, minimum stop rates, etc.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.687-690
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• 2000

Lately, many studies have been progressed for the protection human's lives and property as holding in check accidents happened by human's carelessness or mistakes. One part of these is the development of an autonomouse vehicle. General control method of vision-based autonomous vehicle system is to determine the navigation direction by analyzing lane images from a camera, and to navigate using proper control algorithm. In this paper, characteristic points are abstracted from lane images using lane recognition algorithm with sobel operator. And then the vehicle is controlled using two proposed auto-steering algorithms. Two steering control algorithms are introduced in this paper. First method is to use the geometric relation of a camera. After transforming from an image coordinate to a vehicle coordinate, a steering angle is calculated using Ackermann angle. Second one is using a neural network algorithm. It doesn't need to use the geometric relation of a camera and is easy to apply a steering algorithm. In addition, It is a nearest algorithm for the driving style of human driver. Proposed controller is a multilayer neural network using Levenberg-Marquardt backpropagation learning algorithm which was estimated much better than other methods, i.e. Conjugate Gradient or Gradient Decent ones.

• 한국안전학회지
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• 제33권1호
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• pp.135-141
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• 2018

Rotary that causes traffic delays and safety issues by high-speed entry vehicles is currently being improved to roundabout. The operational difference between rotary and roundabout can cause driver's confusion and traffic accident. The purpose of this study is to develop the accident rate models which explain the factors related to the accidents by land use and intersection type. The main results are as follows. First, the null hypotheses that the type of land use and two intersections do not affect the accident rate are rejected. Second, the conflicting factors such as the number of crosswalk and bicycle lane should be carefully considered to reduce traffic accident at rotary. In the case of roundabout, greater than 3.5 m in circulatory lane width and two circulatory lane are analyzed to be important to prevent the accidents. Finally, the commercial and mixed areas are evaluated to be weak to traffic accidents than residential area.

• 정보통신설비학회논문지
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• 제8권4호
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• pp.170-181
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• 2009

When a slow-moving vehicle occupies one of the lanes of a multi-lane highway, it often causes queuing behind, unlike one is caused by an actual stoppage on that lane. This happens when the traffic flow rate upstream from the slow vehicle exceeds a certain critical value. This phenomena is called as the Moving Bottleneck, defined by Gazis and Herman (1992), Newell (1998) [3], and Munoz and Daganzo (2002), who conducted the flow estimates of upstream and downstream and considered slow-moving vehicle speed and the flow ratio exceeding slow vehicle and the microscopic traffic flow characteristics of moving bottleneck. But, a study of delay on moving bottleneck was not conducted until now. So this study provides a average delay time model related to upstream flow and the speed of slow vehicle. We have chosen the two-lane highway and homogeneous traffic flow. A slow-moving vehicle occupies one of the two lanes. Average delay time value is a result of AIMSUN[9], the microscopic traffic flow simulator. We developed a multiple regression model based on that value. Average delay time has a high value when the speed of slow vehicle is decreased and traffic flow is increased. Conclusively, the model is formulated by the negative exponential function.

• 한국발생생물학회지:발생과생식
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• 제16권1호
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• pp.47-51
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• 2012

Genomic DNAs (gDNAs) were isolated from the hard clam ($Meretrix$ $lusoria$, Roding, 1798) populations of Gunsan located in the Yellow Sea of the Korean peninsula. Genetic distances among different individuals of the LSCP (light shell color population) population of the hard clam (lane 1-11), GSCP (grey shell color population) population of the hard clam (lane 12-22) and DSCP (dark shell color population) population of the hard clam (lane 23-33), respectively, were generated using Systat version 10 according to the bandsharing values and similarity matrix. The dendrogram, generated by seven reliable oligonucleotides primers, indicates 3 genetic clusters. LSCP population could be evidently discriminated with the other two populations among three populations. The longest genetic distance (0.801) was found to exist between individuals in the two populations, between individuals' no. 33 of the DSCP population and no. 06 of the LSCP population. The higher fragment sizes (>2,000 bp) are much more observed in the GSCP population. Three hard clam populations can be clearly distinguished, especially, by their morphological characters and PCR-based approach.