• Title/Summary/Keyword: 횡단속도

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Experimental investigation of depositional patterns of debris flow (횡단 배수로 내 토석류 퇴적 양상의 실험 연구)

  • Kim, Young-Il;Paik, Joong-Cheol
    • Proceedings of the Korea Water Resources Association Conference
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    • 2011.05a
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    • pp.38-42
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    • 2011
  • 토석류는 산간지역에서 발생할 수 있는 가장 위험한 자연재해 중 하나로 입자-유체 혼합물인 토석류가 중력에 의해 매우 빠른 속도로 이동하는 현상을 의미한다. 산간지역에서의 토석류 발생은 도로의 횡단 배수 구조물의 통수능을 저하시키게 되며 그 결과 도로의 유실 등 막대한 피해를 발생시킨다. 잠재적인 토석류 발생 지역에서의 피해 저감을 위해서는 진보된 설계 기준이 마련되어야 하며 이를 위해 토석류의 횡단 배수구조물 내에서 토석류의 동적 거동 특성을 파악하는 것이 선행되어야 할 것이다. 이번 연구에서는 수리 실험을 통하여 횡단 배수구조물 내에서 토석류의 퇴적 특성을 파악하고자 한다. 수리 실험 장비는 폭이 일정한 사각형 수로로 접근 수로와 하류부 수로로 구성되어 있으며 접근수로의 상단부에서 일정한 유량의 토석류를 연속적으로 유입시켜 경사가 급변하는 하류부 수로 내에서의 토석류 퇴적 특성을 파악하였다. 실험 결과로 토석류의 거동 특성은 토석류의 체적 농도, 입자의 특성, 그리고 접근수로와 하류부 수로의 바닥 경사에 종속됨을 정량적으로 알 수 있었다. 또한, 토석류의 체적 농도나 수로 바닥경사 등과는 상관없이 토석류의 퇴적은 하류부 수로의 종단부인 자유 낙하 지점에서부터 시작되었고 시간이 경과함에 따라 퇴적 지점이 접근 수로 쪽으로 이동하며 퇴적량이 크게 증가하는 현상을 보였다. 이 때, 하류부 수로 내 퇴적된 토석류는 약 $12{\sim}15^{\circ}$의 경사를 보였다.

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An Investigation of Road Crossing Behaviour of Older Pedestrians at Unsignalized Crosswalk (무신호 단일로 횡단보도에서 고령 보행자의 횡단행태조사 및 분석)

  • JANG, Jeong Ah;KIM, Junghwa;CHOI, Keechoo
    • Journal of Korean Society of Transportation
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    • v.34 no.3
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    • pp.207-221
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    • 2016
  • In Korea, older pedestrian accounted for 57% of all pedestrian deaths although a ratio of older pedestrian accidents to total pedestrian accidents was only 25.9%. Though ageing population problem becomes more challenging for road safety, little is know about the behaviour of older pedestrian's behaviour. This study aimed to identify road crossing behaviour of older pedestrian at three-lane unsignalized crosswalks using video image analysis and to compare the behaviour of older pedestrian to younger one by indicators including approaching speed, the number of walking steps and other factors. The results showed that there was a difference of approaching time at kerb, waiting time at kerb, the number of glances at kerb, and the number of glances at crossing between two groups under the situation of car approaching to crosswalks. It also showed that older pedestrian usually spent 1.16 times more than younger pedestrian to walk across the crosswalk with only 84.4% of walking speed of younger pedestrian. The number of steps of older pedestrian for road crossing was 1.12 times higher with 90% shorter steps than younger pedestrian. It was concluded that older pedestrian usually decided to walk across in case of 1.67 times longer headway than younger pedestrian's decision. These results could be applied in road and facility design for better safety of older pedestrians.

Safety Analysis on Pedestrian Crossings in Urban Corridors with Bus Rapid Transit System (중앙버스전용차로 횡단보도의 보행 안전도 평가)

  • Han, Sang-Jin;Kim, Kewn-Jung
    • International Journal of Highway Engineering
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    • v.10 no.4
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    • pp.1-8
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    • 2008
  • Seoul metropolitan government has introduced Bus Rapid Transit (BRT) systems in some major urban corridors on July 1st, 2004, and has reported that it was successful on the ground that bus speed has been increased in the corridors with BRT system and that it has also resulted in the increase of bus patrons. However, there comes a negative claim that BRT has increased the number of fatalities in the same corridors. This study first aims at developing safety evaluation indicators of pedestrian crossings, then compares values of those indicators from pedestrian crossings with and without BRT systems. The safety evaluation indicators of pedestrian crossing are developed as: the number (or ratio) of conflicts between pedestrians and vehicles, the number (or ratio) of vehicles violating pedestrian signals, the number (or ratio) of pedestrians remaining crossings at red signals, and the number (ratio) of pedestrians walking beyond crossing areas. When we compare values of these indicators for both pedestrian crossings with and without BRT system, it has turned out that crossings with BRT systems has more number of conflicts than the crossings without BRT systems, but it cannot be said that the ratio of conflicts will be different between two crossing types. It means that the number of conflict will increase as the number of pedestrians and vehicles in the crossings. When we note that BRT system intrinsically attract more number of pedestrians who get-in or get-off bus stops, we cannot said that BRT system will be safer for pedestrians.

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음속돌파로부터 50년!!!

  • Seo, Byeong Hong
    • Aerospace Industry
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    • v.58
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    • pp.44-47
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    • 1997
  • 1947년 10월 14일 미국 캘리포니아주 상공을 1대의 로켓 비행기가 화살처럼 지나가면서 쾅하는 엄청난 충격음을 냈다. 이것이 인류가 처음으로 음속 이상의 속도로 날아간 최초의 음속돌파 순간으로 항공기가 달성한 사상 최초의 소닉 붐이었다. 오늘날에는 초음속 비행이 군용기 부문에서는 당연지사가 되었으며 여객기 분야에서도 콩코드기가 마하 2.0의 속도로 대서양을 가볍게 횡단하고 있다.

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비즈니스 민첩성 향상을 위한 EAI 접근 방안 및 구현 전략

  • 이장석;홍정기;지정권
    • Communications of the Korean Institute of Information Scientists and Engineers
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    • v.22 no.7
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    • pp.13-21
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    • 2004
  • 화약 냄새가 자욱한 전장의 막사에서 취침하려는 나폴레옹은 매일 같은 지시를 하고 잠들었다고 한다. "좋은 소식은 깨우지 말고, 나쁜 소식은 깨우라." 그는 속도의 중요성을 인지한 리더였다. 2003년 우리는 마젤란 시대에 비하여 240배 빠르게 살고 있다. 초속 3백m의 점보기가 10시간에 가로지르는 태평양을 마젤란은 1520년에 약 1백일 간의 항해로 횡단하였다.항해로 횡단하였다.

A Study on Introduction of Bike Exclusive Signal Focused on Traffic Condition (국내 교통여건을 고려한 자전거전용신호 도입방안 연구)

  • Han, Won-Sub;Whang, Sang-Ho;Hyun, Cheol-Seung;Lee, Ho-Won;Oh, Yong-Tae;Lee, Choul-Ki
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.7 no.5
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    • pp.77-89
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    • 2008
  • The bikes are conflicted with the cars and the pedestrian at the intersection and the road with the bike crossing. To establish the bike signal at this section is one method to solve this conflict. According to the survey for the bike road status and the biker's characters which are crossing the road at the intersection, the bike crossing are established with beside the pedestrian crossing and most of the bikers are crossing the street by the pedestrian signal. Also, the bike queue which is waiting the signal change at the stop line was cleared before the closing the pedestrian signal. Considering the result of this survey, TOUCAN crossing signal type in England for bike signal at the place where the bike crossing are established with beside the pedestrian crossing, in which bike rider and pedestrian can cross by the pedestrian signal operation, is suggested. However, at the place where the bike crossing is apart from the pedestrian crossing, the bike signal which is connected to the vehicle signal is suggested. All these types of bike signals can be accepted for the present bike crossing equipments and the biker's characters and be adapted to the police standard traffic signal controller by adjusting the signal time only without any function change.

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Analysis on the Effect of Vehicle Speed Change on the Vehicle Information Guide System for Pedestrian Safety (보행자 안전을 위한 차량정보안내시스템 도입에 따른 통행속도 변화에 미치는 영향 분석)

  • Kwang-Bok Jung;Yeong-YUL Kim;Jae-Yoon Han
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.22 no.1
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    • pp.93-102
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    • 2023
  • This study conducted an effect evaluation before and after the installation of a vehicle information guidance system that provides drivers with information about vehicle speed and the presence or absence of pedestrians near pedestrian crossings. There are three types of scenarios: when no information is provided to the driver (S1), when only the vehicle driving speed is provided (S2), and when pedestrians are present on the pedestrian crossing and when both vehicle driving speeds are provided (S3). did. As a result of the survey, the speed reduction rate of the vehicle was found to be about 0.4~0.7km greater in S2 and S3 that provide information to the driver than in scenario S1. In addition, in the scenario S3, the speed reduction rate is 0.2km higher than that in the case where there are pedestrians near the pedestrian crossing, which further reduces the vehicle speed. Statistical analysis also showed that there was a difference in the speed reduction rate of the average vehicle for the three scenarios, and that the speed reduction rate was large in the presence of pedestrians.

Analysis on Hydraulic Characteristics in Natural Fishway by using Flow-3D (Flow-3D를 이용한 자연형 어도 수리학적 특성 분석)

  • Yoon, Jae Seon;Ha, Taemin
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.513-513
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    • 2016
  • 하천의 횡단 수공구조물인 보 및 낙차공은 구조물 상 하류 생태계의 단절을 발생시켜 회귀성 어류 등 하천 생물의 생존을 위협하고 있다. 최근의 하천 설계는 자연형 하천조성사업과 같이 하천의 치수 및 이수뿐만 아니라 하천생태에 많은 관심이 집중되고 있다. 또한, 하천의 생태적 통로가 단절되는 것을 막기 위해 하천 횡단 구조물인 보와 낙차공에 어도를 설치하고 있다. 어도의 설계는 어도 내의 수리학적 특성을 파악하여 그 기능을 충분히 수행할 수 있는지 여부를 분석하여야만 한다. 본 연구에서는 기존에 제시되지 않았던 자연형 어도를 제안하고, 3차원 유체의 흐름성분을 해석할 수 있는 범용프로그램 FLOW-3D를 이용하여 수리학적 특성을 파악하였다. 또한, 어종별 돌진속도에 따른 자연형 어도의 기능적 활용여부를 제시하고자 한다.

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Alternative to Improve the Lighting of Crosswalk on Rural Highways (지방지역 도로 횡단보도 조명 개선 방안)

  • Lee, Suk-Ki
    • The Journal of the Korea Contents Association
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    • v.13 no.3
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    • pp.435-443
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    • 2013
  • While rural highways carry on lower traffic volumes, the deviations of running speeds between vehicles appear to be higher on rural highways than urban highways. The speed characteristic of rural highways is adding to pedestrian-related accidents which occur on a crosswalk with poor sight distance due to the limits of car headlights and lighting. Specially, the aged was mostly occupied in nighttime-related accidents on crosswalks, and pedestrians crossing on the far side of approaching vehicles appear to have the probability of fatality higher than the near side. An alternative is needed to resolve the compounded accidents, and then this study is to establish a new approach to an optimum lighting environment on a crosswalk to improve pedestrian safety. This study was conducted by a survey and a field study on the lighting of existing crosswalks. The field study shows that the existing lighting has the problem of wasting energy and impeding walking due to glare. The survey shows that nighttime sight distance on a crosswalk is required to improve and that road users prefer to be brighter pedestrian waiting space together with the crosswalk. Thus, a lighting environment that is not too bright and illuminates the crosswalk and the pedestrian waiting space is needed to implement.

A Study on Automatic Signal Control System Using Real-Time Image Processing (실시간 영상처리를 이용한 자동 신호제어시스템에 관한 연구)

  • Oh, Se-Jun;Kwon, Se-Bin;Cho, Yun-Seol
    • Proceedings of the Korea Information Processing Society Conference
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    • 2021.11a
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    • pp.1249-1252
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    • 2021
  • 이 시스템은 openCV와 딥러닝 학습모델을 이용하여 횡단보도의 상황을 파악하고 횡단보도위의 객체를 추출하여 자동으로 신호를 제어할 수 있다.보행자를 인식하여 노인, 장애인 등 보행속도가 느린 보행자들을 위해 횡단보도의 신호를 추가하여 보행자의 교통사고를 줄일 수 있다. 또한 교통흐름도 고려하여 차량운전자와 보행자 모두에 도움이 되는 시스템 구현을 목표로 한다.