• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1723-1726
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• 2003

Clean and well maintained roadway signs are important for preserving driver's safety. The existing signs on the roadway must be periodically re-painted in order to maintain clean state. However, current sign painting operations are manually performed now. These are very slow and workers are exposed to very dangerous and hazard working environment. In this paper, we present the method for automating this job with gantry robot and spray system. In addition, we suggest two design concepts to resolve the problem that it is impractical to make the gantry system so big as to cover whole lane width. In order to show the validity of this system, the painting operation is simulated and experimentally executed.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2001년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2001
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• pp.295-301
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• 2001

For the seismic analysis of typical roadway bridges provisions are given in most codes for analysis models, which describes however only fundamental modelling methods according to the basic theories of structural dynamics. In practice even conventional non-seismic analysis models, separate super- and substructure models, are applied, which are not adequate because of neglecting connection elements. In this study three typical roadway bridges, a Steel box bridge, a PC beam bridge and a PC box bridge are selected and simple models integrating super- and substructure as well as connection elements are given. The simple models are composed with frame elements with lumped masses representing stiffness and mass characteristics of the selected bridges. To check the properness of the simple models, analysis results with the simple models are compared with those obtained with detailed models in view of bridge failure mechanisms. It is proved that the simple models can be used in the preliminary design phase fur the determination of failure mechanisms of typical roadway bridges.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1518-1523
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• 2003

Automation of roadway sign painting offers more safety for workers, shortening of work period, etc., compared with manual painting. In this study, an automated system using a gantry-type robot was developed for roadway sign painting which has been done manually. Any characters (Korean and English) as well as symbols can be painted by the system. A simulator was also developed, which can show the painted results in advance. The developed system performed well, and the signs painted by the system were found to be as accurate as those made by the simulator.

• 조명전기설비학회논문지
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• 제22권1호
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• pp.17-23
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• 2008

본 논문에서는 2분할 수광 방식의 측정시스템을 이용하여 수도권 일대의 도로의 조도와 휘도분포를 측정하여 국내 도로조명 실태를 파악함으로써 조명시설들의 특징에 대하여 분석했다. 측정결과 대다수의 도로가 도로의 형태, 조명기구의 점등방식, 도로주변의 가로수 혹은 장애물 등의 영향으로 도로조명 허용기준을 만족시키지 못하고 있었다.

• International Journal of Ocean System Engineering
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• 제2권2호
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• pp.92-96
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• 2012

This study presents a rockfall impact analysis of a typical roadway. Dynamic finite element analyses using ANSYS AUTODYN are conducted to determine the effect of the drop heights (5 m, 10 m) on the damage to a roadway model. The Rockfall is modeled as a spherical shape with a weight of 400 kg, and each drop height is converted to a corresponding impact velocity to save computational time. The roadway model is comprised of an asphalt layer, base layer, sub-base layer, and sub-grade layer. In this paper, the asphalt is modeled using a linear elastic model. The base layer, sub-base layer, and sub-grade layer are modeled using a Mohr-Coulomb model. From the analyses, the effects of the drop height on the damages and stresses are examined and discussed.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.376-380
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• 2015

Life-Cycle Cost Analysis (LCCA) for highway projects is known as an effective analytical technique that uses economic principles to evaluate long-term alternative investment options, especially for comparing the values of alternative pavement design structures and construction strategies. In the Unites States, the 2012 Moving Ahead for Progress in the 21^st Century Act (MAP-21) amended the United States Code to mandate that the United States Government Accountability Office (GOA) conducts a study of the best practices for calculating life-cycle costs and benefits for the federally funded highway projects in 2013. The RealCost 2.5CA program was developed and adapted as an official LCCA tool to comply with regulatory requirements for California state highway projects in 2013. Utilization of this California-customized LCCA software helps Caltrans to achieve substantial economic benefits (agency cost and road user cost savings) for highway projects. Proper implementation of LCCA for roadway construction and rehabilitation would deliver noticeable savings of agency's roadway maintenance cost especially in developing counties where financial difficulties exist.

• 대한교통학회지
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• 제19권6호
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• pp.255-256
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• 2001

• 터널과지하공간
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• 제24권3호
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• pp.212-223
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• 2014

본 연구에서는 고심도 금속광산갱도에 대한 안정성 해석을 수행하였다. 이를 위해 수압파쇄법으로 암반의 초기지압을 측정하였고, 현장에서 채취한 암석코어로 수많은 실내물성시험을 실시하여 무결암의 물성 값을 산출하였으며, 현장조사를 통해 GSI, RMR 분류법으로 암반을 분류하였다. 암반분류 결과에 대한 시나리오 분석과 확률론적 평가를 통해 광산 갱도를 최상조건, 평균조건, 최하조건으로 구분하였으며, 각 조건별 탄소성해석을 통해 갱도의 안정성을 평가하였다. 또한, 갱도의 형상과 발파손상대의 영향을 고려한 해석을 통해 갱도의 적절한 규격과 지보패턴을 조사하였는데, 본 광산 갱도의 안정성 제고를 위해서는 갱도의 천반 곡률반경을 감소시키거나 천정부 보강이 필요한 것으로 나타났다.

• 한국ITS학회 논문지
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• 제8권6호
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• pp.162-172
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• 2009

최근 급속한 고령운전자의 증가에 따라 고령운전자의 저하된 운전행태를 수용할 수 있는 도로환경 개선에 대한 노력이 시급하나 아직까지 고령운전자의 사고취약 도로형태에 대한 통계도 집계되지 않고 있는 실정이다. 이에 본 연구는 경찰청 사고통계자료를 이용하여 고령운전자가 사고에 취약한 도로형태 및 취약 정도를 분석하였으며 해외사례를 바탕으로 고령운전자 사고취약 도로형태별 개선 방안을 제시하였다. 국내 고령운전자는 비고령운전자 대비 교차로 사고, 곡선로에서의 차대차 사고 발생확률이 높은 것으로 나타났으나 곡선로 상 차대차 사고는 두 집단간 큰 차이를 보이지는 않았다. 또한 고속도로 인터체인지도 고령운전자 사고취약 도로 형태에 포함시켜 램프 부근에서의 사고감소방안을 살펴보았다.

• Geomechanics and Engineering
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• 제29권5호
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• pp.567-582
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• 2022

In the present study, a series of physical experiments and numerical simulations were conducted to investigate the effects of mode I and mixed-mode I/II cracks on the fracture modes and stability of roadway tunnel models. The experiments and simulations incorporated different inclination angle flaws under both static and dynamic loads. The quasi-static and dynamic testing were conducted by using an electro-hydraulic servo control device and drop weight impact system (DWIS), and the failure process was simulated by using rock failure process analysis (RFPA) and AUTODYN software. The stress intensity factor was also calculated to evaluate the stability of the flawed roadway tunnel models by using ABAQUS software. According to comparisons between the test and numerical results, it is observed that for flawed roadways with a single radical crack and inclination angle of 45°, the static and dynamic stability are the lowest relative to other angles of fractured rock masses. For mixed-mode I/II cracks in flawed roadway tunnel models under dynamic loading, a wing crack is produced and the pre-existing cracks increase the stress concentration factor in the right part of the specimen, but this factor will not be larger than the maximum principal stress region in the roadway tunnel models. Additionally, damage to the sidewalls will be involved in the flawed roadway tunnel models under static loads.