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        검색결과 8

        1.
        2024.03 구독 인증기관 무료, 개인회원 유료
        자율주행차 상용화 시대를 가속화하기 위해 실제 도로에서 다양한 실증 프로젝트를 수행중이다. 그러나, 자율주행차와 비자율주행차 가 혼재된 혼합교통류 환경에서 발생할 수 있는 다양한 문제의 원인을 파악하고 선제적인 안전대책을 강구하는 노력은 미비한 실정이 다. 특히, 기존 비자율주행차 측면의 주행안전성을 고려하여 설계된 도로 시설 특성으로 인해 자율주행차의 주행안전성이 저하될 수 있다. 또한 기존 비자율주행차의 주행안전성을 저해함과 동시에 자율주행차의 주행안전성도 저해하는 도로 시설 특성이 존재할 가능 성이 있다. 본 연구에서는 상암 자율주행차 시범운행지구에서 수집된 automated vehicle data (AVD)를 활용하여 자율주행차와 비자율주 행차의 주행안전성을 평가하고 도로 시설 특성 측면의 영향요인을 도출하였다. 주행모드별 주행안전성 평가를 위해 autonomous emergency braking system (AEBS) 위험 이벤트 기반의 driving risk index (DRI)를 개발하였다. 구간별 DRI가 발생하지 않은 구간을 very good으로 정의하고 발생한 구간을 25 percentile로 구분하여 good, moderate, poor, very poor 등급으로 정의하여 총 5개의 등급으로 구분 하였다. 또한, 현장조사을 수행함으로써 구간별 포함되어 있는 도로 시설 특성을 수집하였다. 주행모드별 주행안전성에 영향을 미치는 도로 시설 특성을 도출하기 위해 이항로지스틱 회귀분석을 수행하였다. 종속 변수의 경우 DRI 기반 안전등급 중 poor 이상 등급을 1, 그 외의 등급을 0으로 정의하였으며, 독립변수의 경우 현장조사를 통해 수집된 교차로 유형, 차로 수, 차로 폭, 추가차로 유무, 차량 진행방향, 불법주정차 유무, 버스정류장 유무, 자전거 차로 유무에 대해 명목형 변수로 설정하였다. 도출된 주행모드별 주행안전성 영 향 요인을 검토하고 향후 자율주행차 시대에 대비하여 선제적으로 개선이 요구되는 도로 시설 특성을 도출하고 도로 운영성 및 효율 성, 안전성 측면의 개선 방향을 제시하였다.
        3,000원
        2.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study is performed first to define the aging of road facilities and to analyze the effects of environmental factors on the deterioration of median barriers. METHODS : The aging of road facilities is defined using an analytical hierarchy process (AHP). The first stage is associated with the period, facilities, and maintenance, whereas the second stage is associated with the details. The effects of environmental factors on the deterioration are analyzed by measuring the carbonation depth and compression strength. Two regions, i.e., Gangwon and Busan, are compared separately. Top, middle, and bottom samples are analyzed for both regions. RESULTS : Based on the result of the AHP analysis, weights for period (0.220), function (0.410), and maintenance (0.370) are derived. The average carbonation depths are 11.12 and 9.78 mm for Kangwon and Busan, respectively. The estimated values of compressive strength at Gangwon are 19.7 MPa (Wonju), 24.7 MPa (Samcheok A), and 25.9 MPa (Samcheok B), 20.2 MPa (Haeundae), 23.8 MPa (Yeongdo), and 29.5 MPa (Nam). CONCLUSIONS : The aging of road facilities is associated with subpar functionality and durability. Furthermore, the median barriers constructed in the Gangwon region deteriorated more significantly than those in the Busan region owing to environmental factors. In addition, the bottom samples are more affected by aging than the top samples.
        4,000원
        3.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The objective of this study is to analyze the uniform diffusion mechanism of precursor gas species, and the effect of NOx reduction technology in a full-scale particulate matter testing facility, using computational fluid dynamics (CFD). METHODS : A full-scale environment chamber was constructed to evaluate the effects of particulate matter reduction technologies on the road. CFD analysis was conducted to simulate the road environment conditions in the chamber, and investigate the effect of the NOx removal panel. The time required to reach the NOx concentration to target value in the fluid field was determined at a given inflow velocity, inlet direction, and initial inflow concentration. The effect of the NOx removal panel, and solar energy on the reduction characteristics of the NOx concentration in the environment chamber was analyzed. RESULTS : The inflow velocity was determined to be the major factor affecting the time required to reach a uniform target NOx concentration in the environment chamber. The inlet location in the transverse direction requires additional time to approach the uniform target concentration, than the longitudinal direction at the same inflow velocity. Based on the CFD analysis in the 1ppm concentration condition of the chamber, a two-fold increase in the NOx removal panel efficiency can reduce the time to target concentration by approximately 50%. It is also observed that a 20% increase in solar energy can decrease the time to target concentration by 4%–12% depending on the panel efficiency. CONCLUSIONS : This study proved that a full-scale environment chamber can be effectively utilized to evaluate the particulate matter reduction technologies applied in road facilities
        4,000원
        4.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : In this study, the luminance of night road markings was measured in a tunnel of length 200 m or less. The purpose of the project is to evaluate the consistency of night road markings. METHODS : In this study, field measurements were conducted to achieve the purpose of this study. Five tunnels with lengths of less than 200 m were selected to measure the luminance value of the road markings. The analysis of the difference in road markings between the inside and outside points of the tunnel and the analysis of alternative tunnels and points were used to assess the consistency of road markings in tunnels. RESULTS : The average luminance of the tunnel’s night road markings was 9.7, and the standard deviation was 3.0. The analysis of variance for the tunnel and point indicated that the p-value was less than 0.05 and was inconsistent. CONCLUSIONS : In conclusion, consistency was assessed by measuring the luminance value of the short tunnel of length 200 m in the Cheongju Sangju Expressway, and it was confirmed that the luminance of the road markings was not consistent with the tunnel and point. Finally, it is necessary to control night lightings on roads outside the tunnel or adjust lighting facilities in the tunnel to enhance the consistency of luminance.
        4,000원
        5.
        2013.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: This study is to develop a road traffic sign recognition and automatic positioning for road facility management. METHODS: In this study, we installed the GPS, IMU, DMI, camera, laser sensor on the van and surveyed the car position, fore-sight image, point cloud of traffic signs. To insert automatic position of traffic sign, the automatic traffic sign recognition S/W developed and it can log the traffic sign type and approximate position, this study suggests a methodology to transform the laser point-cloud to the map coordinate system with the 3D axis rotation algorithm. RESULTS: Result show that on a clear day, traffic sign recognition ratio is 92.98%, and on cloudy day recognition ratio is 80.58%. To insert exact traffic sign position. This study examined the point difference with the road surveying results. The result RMSE is 0.227m and average is 1.51m which is the GPS positioning error. Including these error we can insert the traffic sign position within 1.51m CONCLUSIONS: As a result of this study, we can automatically survey the traffic sign type, position data of the traffic sign position error and analysis the road safety, speed limit consistency, which can be used in traffic sign DB.
        4,000원
        7.
        2019.04 서비스 종료(열람 제한)
        In this study the frame based-FE model of road facility-supporting structures was created and analyzed to investigate the distributions of seismic forces according to the types of the supporting structures. From the results of response spectrum analysis, the first to third natural periods of most road facility supporting structures are ranged around an effective acceleration response zone in the design response spectrum and the base shear force and base moment increase as the size of the structures increases.
        8.
        2012.04 KCI 등재 서비스 종료(열람 제한)
        도로 배수시설 설계시 수리 및 수문요소 분석이 적절하게 적용되어야 하지만, 현재는 계산의 복잡함 때문에 충분히 고려되지 못하고 있다. 본 연구에서는 강우지속시간이 10분 이하인 도로배수유역에 적합한 분단위 강우강도식의 개발, 국내 도로배수유역의 지형 특성을 사실적으로 반영할 수 있는 운동파 모형 이론을 접목한 표면 박류 강우-유출 모형의 개발 및 검증, 노면 배수시설 설계, 암거 단면규격 산정 및 각종 수로 설계 등의 모형 개발, 개발된 모형들을 도로 설계자가 쉽게 익혀서 신속 정확하게 활용할 수 있도록 사용자 편의를 고려한 도로배수설계 전산프로그램을 개발하였다. 개발된 모형을 이용하여 적용성 검토를 수행하였으며, 현행 설계 방법과 개발된 설계 방법을 비교한 결과 노면 배수시설의 설치 간격은 6∼65% 짧게 계산되었으며, 횡단 배수시설의 단면 크기는 6∼140% 크게 계산되었다.