• 지적과 국토정보
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• 제52권1호
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• pp.81-93
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• 2022

최근 자율주행 기술에서 차량 주변 객체 인식과 교통표지판 및 차량 신호 인식을 위한 연구가 활발히 수행되고 있으며, 특히 차량 신호 인식은 자율주행 기술에 있어서 핵심 요소로 평가되고 있다. 이에 차량 신호 인식을 위한 다양한 연구가 진행되어 왔으며, 최근에는 딥러닝 기반 객체 인식 모델을 활용한 차량 신호 인식 연구가 크게 증가하고 있다. 또한 AIHub에서 음성, 비전, 자율주행 등을 위한 양질의 국내 인공지능 학습데이터 셋이 공개됨에 따라 이들 데이터를 활용한 국내 환경에 적합한 차량 신호 인식 모델의 개발도 가능하게 되었다. 이에 본 연구에서는 AIHub의 학습데이터와 객체 인식모델 YOLO를 적용한 국내 차량 신호 인식 모델을 개발하였다. 특히 차량 신호의 인식 성능을 개선하기 위하여 YOLOv4와 YOLOv5의 다양한 모델을 적용하였으며 학습데이터의 클래스도 다양하게 분류하여 실험을 수행하였다. 결론적으로 YOLOv5가 YOLOv4보다 차량 신호 인식에 조금 더 적합함을 확인할 수 있었으며, 두 모델의 아키텍처 비교를 통하여 YOLOv5 성능이 우수한 이유를 확인할 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권8호
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• pp.2875-2893
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• 2015

Existing coding aware routing algorithms focused on novel routing metric design that captures the characteristics of network coding. However, in packet coding algorithm, they use opportunistic coding scheme which didn't consider the queue state of the coding node and are equivalent to the conventional store-and-forward method in light traffic load condition because they never delay packets and there are no packets in the output queue of coding node, which results in no coding opportunity. In addition, most of the existing algorithms assume that all flows participating in the network have equal rate. This is unrealistic since multi-rate environments are often appeared. To overcome above problem and expand network coding to light traffic load scenarios, we present an enhanced coding-aware routing algorithm based on queue state and local topology (OQMCAR), which consider the queue state of coding node in packet coding algorithm where the control policy is of threshold-type. OQMCAR is a unified framework to merge single rate case and multiple rate case, including the light traffic load scenarios. Simulations results show that our scheme can achieve higher throughput and lower end-to-end delay than the current mechanisms using COPE-type opportunistic coding policy in different cases.

• 자동차안전학회지
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• 제13권3호
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• pp.41-46
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• 2021

The number of big traffic accident cases of pedestrian death appeared to be minor, however compared to death rate in car to car accidents is very high and quite a few of the pedestrian death rates among all traffic accidents are counted to be almost 40%. Previous pedestrian safety studies were mostly aimed at reducing the degree of pedestrian injuries from a vehicle to pedestrian collision, and less at preventing a collision itself. This research was conducted with a method of using road facilities to prevent vehicles from rushing into the sidewalk. This research used one of the collision analyzing programs, called PC-Crash to simulate the vehicle rushing into the sidewalk. Based on the program, it could derive an optimal safe zone location where the pedestrian can wait for the pedestrian light safely. Also, changing road facilities such as pedestrian light pillars or signal controllers can widen 440% compared to the present safe zone. Accordingly, researchers have to consider a method to analyze and apply pedestrian safe zones along with road facilities location when designing a road.

• 대한교통학회지
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• 제8권1호
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• pp.73-88
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• 1990

This study aims to develop a traffic accident forecasting model using the data, which are based on the past accidents in Korea. The regression analysis was used in conjuction with the variables of the traffic accidents and social behaviours. The objectives of this study are as follows; 1. The number of behicles has given a strong affect to increase the traffic accidents in Korea since a factor of vehicles has shown 86% over of total accidents. 2. The forecasting model regarding the traffic accidents, deaths and injuries, which was formulated for this study, proved to be useful in light of the results of the regression diagnostics. 3. It is expected that the traffic accidents in Korea in 1991 may take place as follows on condition that the traffic environment would worsen ; 274,000 cases of accidents with 13,600 deaths and 367,000 injuries, in 1994, 451,000 cases with 24,900 deaths and 71,500 injuries respectively.

• Journal of Korean Society for Atmospheric Environment
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• 제9권E호
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• pp.364-372
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• 1993

The purpose of this study is to analyze traffic patterns by use of TRANSYT-7F Model, and to choose the optimum traffic-light cycle length and cycle splite to improve traffic flow and air quality at Samsung Intersection in Seoul. Emission rates of air pollutants are calculated for three time segments 0700-0900, 0900-1800 and 1800-2000. The traffic volume correlated reasonably well with air pollutants emitted ; however, the phasing and timing of traffic signals was found to equally be important. The results of performance with optimal setting indicate that the best cycle length were 80sec(0700-0900), 95sec(0900-1800) and 90sec(1800-2000), res-pectively. As expected the highest emissions of air pollutants were observed during the evening rush hours (1800-2000). A properly designed signalized intersection can help reduce traffic delay, driver discomfort, fuel consumption, and air pollution by efficiently the capacity of existing intersection.

• 한국ITS학회 논문지
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• 제8권5호
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• pp.114-120
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• 2009

In outdoor visible light communication channels and LED road illumination communications for the intelligent transport systems (ITS), inter symbol interference (ISI) due to multipath propagation prevents high data rate transmission. Indoor wireless optical communication systems utilizing white LED lights and on the road illumination have been studying about it. Generally, plural lights are installed in room and considered to the traffic information system using existing LED traffic lights. Therefore, their optical path difference must be considered. In this paper, the influence of an optical path difference has been investigated and two approaches against this problem are introduced. One uses on-off keying, return-to-zero (OOK-RZ) coding and the other uses optical orthogonal frequency division multiplexing(OFDM).

• Journal of applied mathematics & informatics
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• 제8권3호
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• pp.1035-1045
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• 2001

We present two decomposition approximations for the mean sojourn times in open single class queing networks. If there is a single bottleneck station, the approximations are asymptotically exact in both light and heavy traffic. When applied to a Jackson network or an M/G/1 queue, these approximations are exact for all values of the traffic intensity.

• 대한교통학회지
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• 제30권6호
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• pp.93-102
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• 2012

도시지역의 교통사고 중 교차로와 관련한 교통사고가 교통사고 건수와 교통사고 심각도에서 가로구간이나 횡단보도 관련 교통사고에 비해 높게 나타나고 있다. 특히 교차로에서 신호위반으로 인한 교통사고는 다른 교통사고유형과는 달리 중상과 경상에 관련된 교통사고비율이 높은 것으로 나타나고 있다. 이에 우리나라는 물론이고 많은 외국에서 신호위반으로 인한 교차로 교통사고를 줄이기 위하여 교차로 신호위반 단속카메라를 설치하고 있다. 이와 더불어 교차로 신호위반 단속카메라의 교통사고 감소에 미치는 효용에 대한 연구가 계속 이루어지고 있으나 신호위반 단속카메라만의 효과를 분석하기란 쉽지가 않다. 따라서 본 연구에서는 미국 Illinois주 Chicago시의 다운타운의 교차로 관련 데이터를 이용하여 SPF모형을 개발하고 개발된 모형을 활용하여 EB방법으로 교차로 신호위반 단속카메라의 효용에 대하여 분석하였다. 분석 결과, 목표로 지정한 교통사고 유형(측면직각추돌, 후방추돌, 같은 방향 측면추돌, 반대 방향 측면추돌, 회전시 추돌, 그리고 정면충돌)과 전체 교통사고유형 모두가 교차로 신호위반 단속카메라의 영향을 받는 것으로 나타났다. 전반적으로 신호위반 단속카메라 사망사고가 약 26% 감소한 것으로 나타났으며, 전체 사고는 5.49% 증가하는 것으로 나타났다. 또한 대물교통사고의 경우 3.23% 증가하는 것으로 나타났다. 또한 목표로 한 사고유형에 대한 교통사고효과 분석에서는 사망사고는 약 38% 감소한 것으로 나타났으며 전체 사고의 경우 1.46% 증가하는 것으로 나타났다. 또한 대물교통사고의 경우 1.16% 증가하는 것으로 나타났다.

• 대한교통학회지
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• 제14권1호
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• pp.101-116
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• 1996

Increased attention has been paid in recent years to the need of traffic management for alleviating urban traffic congestion. This paper presents a discrete event modeling and simulation framework for analyzing the traffic flow. Traffic simulation models can be classified as being either microscopic and macroscopic models. The discrete event modeling and simulation technique can be basically employed to describe the macroscopic traffic simulation model. To do this, we have employed the System Entity Structure/Model Base (SES/MB) framework which integrates the dynamic-based formalism of simulation with the symbolic formalism of AI. The SES/MB framework supports to hierarchical, modular discrete event modeling and simulation environment. We also adopt the Symbolic DEVS (Discrete Event System Specification) to developed the automated analysis methodology for generating optimal signal light policy. Several simulation tests will demonstrates the techniques.

• 한국산학기술학회논문지
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• 제14권11호
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• pp.5334-5337
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• 2013

본 논문에서는 도심 미관의 보완을 위해 와이어를 제거한 교통신호등의 구조 해석을 수행한다. 실제 교통신호등의 3차원 CAD 모델로부터 쉘 요소로 이루어진 유한요소 모델을 생성하였고, 특히 교통신호등의 지주 및 가로재는 모양, 두께, 보강재 등을 고려하였다. 풍하중을 적용하여 응력 및 변형 해석을 수행하였으며, 풍하중이 적용될 경우에 교통신호등에 미치는 결과를 분석하여 설계 개선에 대한 기본 작업을 수행하였다.