• 한국도로학회지:도로
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• v.19 no.1
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• pp.44-47
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• 2017

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1996.11a
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• pp.26-33
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• 1996

광원에 대하여 서로 다른 여러개의 각도방향에서 광원을 바라볼 때 관측되는 광도분포 및 재귀반사성능을 측정하기 위해 광도분포 측정장치(배광측정기)를 제작하였다. 이 장치는 광원을 좌우로 360도, 상하로 $\pm$30도 회전시킬 수 있는 광원회전장치, 광검출기로 광전자중배관(PM Tube)을 쓰는 수광부 및 재귀반사성능 측정용 투광기와 제어 및 표시부로 구성되어 있다. 광도 측정범위는 0.01-199900 cd , 관측각범위은 0.2-1.5도 이고 광도의 측정오차는 $\pm$3% 이다. 제작된 장치의 구조와 성능평가결과가 제시되었다.

• International Journal of Highway Engineering
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• v.14 no.1
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• pp.9-16
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• 2012

The performance of road markings is classified into the visibility at daytime, night time, wet condition and rainy conditions. The objective of this study is to obtain the driving safety of drivers under conditions of unstable weather condition such as the rain. The visibility of road markings is closely related to the preview time and detection distances and the ways to improve road marking materials and increase the dry retroreflectivity and wet retroreflectivity, which are the measures of daytime and nighttime visibility is researched to decrease the traffic accidents. For this purpose, Road marking glass beads with the refraction rate of 1.5 and 2.2 are introduced to raise the retroreflectivity. After investigating the minimum threshold retroreflectivity and Install Minimum retroreflectivity at home and abroad, minimum control values for the roadmarking visibility and improvement of nightime rainy retroreflectivity are suggested by physical properties and retroreflectivity experiments.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.185-194
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• 2014

This study investigates the methodology to evaluate the quantified performance of pavement markings and traffic guide signs using digital images. This methodology is significant to attempt to quantify their performance without large brightness photometer at the nighttime and bad weather. The retroreflective performance of pavement markings are evaluated through the contrast of gray levels of pavements and markings in collected digital images under the case of rain, dampness, and dryness. In addition, the appraisal of retroreflective performance of traffic guide signs are implemented through the comparison between interior illuminated and the existing retroreflective traffic guide signs using the contrast of luminance extracted from the value of RGB of backgrounds and legends in collected digital images according to geometric design, driving lanes, and the distance between the car and the sign. As a result, the retroreflective performance of pavement markings deteriorates about 3.5 times and 2 times under the case of rain and dampness respectively than dryness. Also, the performance of the existing traffic guide signs is significantly influenced by geometric design, driving lanes, and the distance, otherwise interior illuminated traffic guide signs. This methodology can be utilized to construct objective information of performance of traffic safety facilities to select appropriate position of expensive high reflective pavement markings and interior illuminated traffic guide signs considering diverse weather and geometric design.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.10 no.4
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• pp.53-61
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• 1996

A distribution photometer was constructed to measure the angular distribution of luminous intensity of light sources and the reflected luminance of retroreflectors. This system incorporates a goniometer to rotate test light source(360 degree in yaw rotation and $\pm$30 degree in pictch rotation), a photomultiplier tube as light detector, light projector for retroreflection measurements, and the control and display unit. The ranges of luminous Intensity measurements and observation angles are 0.01~199900 cd and 0.2~1.5 degree respectively. The uncertainty of luminous intensity measurements is $\pm$3%. This paper describes the construction of the distribution photometer and the performance characteristics.

• Applied Chemistry for Engineering
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• v.26 no.4
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• pp.439-444
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• 2015

Several attempts to design the best-available thermosetting road markings by using MMA to improve the durability and retroreflectivity are presented in this paper. In order to improve field applicability, the components of main materials were designed by means of reducing the hardening time lower than eight minutes. The optimum mixing ratio of thermosetting road marking was TSRM-6 composed of 15.6 wt% of MMA monomer ($Tg=105^{\circ}C$), 6.0 wt% of PMMA (MW = 70,000, $Tg=60^{\circ}C$) and 1.2 wt% of TMPTA (MW = 338, $Tg=27^{\circ}C$). Also the homogeneous mixing of all components was necessary. The use of ceramic glass beads with an optimized TSRM-6 exhibited excellent performance by achieving retroreflectivity coefficients of 431, 354 and $172mcd{\cdot}m^{-2}{\cdot}lux^{-1}$ for dry, wet and rainy test condition, respectively at two hundred thousand cycles.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.6
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• pp.37-48
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• 2020

Eight colors prescribed by the Enforcement Rules of the Road Traffic Act and the group standard were tested to secure the minimum recursive reflectance performance standards when drying and wetting. The results were calculated to be 260.8 (mcd/㎡·lux) when drying white and 154.6 (mcd/㎡·lux) when wet. Yellow was 67% compared to the white reflective performance when drying. Wet poetry was 79 % and 59 %, respectively. In the case of blue, it was 64% in the case of white versus 72% in the case of white. Wet poetry was 63 % and 72 %, respectively. The range of changes in reflective performance during wetting was higher than when drying, and the absence of glass grains was similar to the previous results. The new colors also have a standard value of more than 50% compared to the white color in red, orange, pink, light green, and green. Based on this, it was estimated that the minimum reflective performance criteria according to the color of the road markings would form the basis for the enforcement rules of the Road Traffic Act.

• Applied Chemistry for Engineering
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• v.28 no.1
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• pp.35-41
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• 2017

Materials exposed to outside will deteriorate due to various weathering factors such as sunlight, heat, temperature, humidity and so on. Therefore, predicting speed of degradation and life time is a very important issue. This research uses retro-reflective sheets with white and green which are most commonly used colors to conduct the outdoor exposure test and acceleration test of xenon arc in Arizona state in the United States, Chennai in India, Sanary in France and Seosan in Korea to measure the reflective performance of retro-reflection. The accelerated factor was obtained by using regression analysis through reflective values obtained from the acceleration test of xenon arc from Seosan area. Also, by using solar uv program, the accelerated factor of various climate regions were obtained and it was confirmed that the accelerated factor of Senary was 1.04, Arizona 1.82, Chennai 1.92 times higher than that of Seosan.

• Proceedings of the KOR-KST Conference
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• 1998.10a
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• pp.342-351
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• 1998

노면표시는 운전자에게 시선유도와 각종 규제 및 지시에 대한 정보를 제공함으로써 교통안전 및 소통에 도움을 주는 시설로써 주야간의 시인성 확보가 중요하며 이를 위해서는 반사화가 필요하다. 노면표시의 반사성능은 유리알 (Glass Bead)의 함량 및 종류, 용융온도, 도료의 색도등 각 영향인자에 의해 결정되지만 현재는 시공법 및 관련 연구의 미흡으로 현행기준의 최하수준을 상회하는 정도로 제공되고 있다. 따라서 본 연구에서는 노면표시의 시공에 관계되는 각 요인중 반사성능가 내구성에 영향을 미치는 주요인자 및 반사성능을 최적화하기 위한 인자별 최적조합을 도출하였다. 연구결과 유리알 살포량이 중량비로 25%-30%, 용융시 온도가 $188^{\circ}C$$\pm$$10^{\circ}C$일 때 노면표면시의 반사성능이 최적화됨을 밝혀내었다. 또한 유리알의 품질개선과 함께 황색 노면표시의 재귀반사 휘도계수 기준을 현재 기준보다 상향조정할 필요성이 있음을 제안하였다.

• Elastomers and Composites
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• v.46 no.4
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• pp.277-283
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• 2011

In this study, engineering grade and high intensity reflective sheets were prepared with glass beads and their reflection performance and physical properties were investigated. The reflective sheets prepared by using glass beads are divided into enclosed or encapsulated lens type, depending on whether the glass beads are open in air or not. Because of an extra layer on the glass bead surface, the enclosed lens type reflective sheets show very little change in the properties by bad weather conditions, compared to encapsulated lens type reflective sheets. Optimization of the amount of glass beads on the surface was carried out, which determines the retroreflective properties. Enclosed and encapsulated lens type reflective sheets with various colors were prepared and their coefficients of retroreflection were determined. The encapsulated type reflective sheet with white color shows a coefficient of retroreflection of $210.4cd/1x{\cdot}m^2$, which is higher than the enclosed type ($74cd/1x{\cdot}m^2$). Effect of washing on the reflective property and adhesive power of the reflective sheets was investigated, and it is found that the number of glass beads decreased with washing and the aluminum layer deposited was damaged extensively in the encapsulated lens type reflective sheets.