• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.312-318
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• 2022

Robot-based layout automation has been recently promoted for the purpose of improving productivity and quality. Marking robots have various functional demands to secure marking precision and environmental adaptability. In particular, in order to automate marking work of building structure, correction of the marking line through position recognition of rebars placed is required. Because the rebars must maintain a constant cover thickness from the formwork surface, if the rebars are out of planned position, the rebar or marking line need to be corrected to secure the cover thickness. Thus, the marking robot for structural work needs to have the function for determining the position correction of the rebar or the marking line. In order to judge the correction of marking line, it is required to measure the distance between the planned marking line and the rebar placed. Therefore, this study proposes an algorithm that can measure the distance between the planned line and the rebar, and correct marking line for the automatic operation of the marking robot. The results of this study will be utilized as a core function for unmanned operation of the marking robot and contribute to securing precise marking by reflecting construction errors.

• 한국도로학회논문집
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• 제18권4호
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• pp.69-75
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• 2016

PURPOSES : In this study, we evaluated changes in the retroreflectivity and luminance of phosphorescent road line markings with changes in glass beads and line marking thickness. METHODS : The color of line markings affects their retroreflectivity. Using a chromaticity test, we conducted the analysis of whether phosphorescent road line markings adhered to the "KS M 6080" standard. Then, we measured the dry retroreflectivity and wet retroreflectivity for various glass bead refractive indices. We conducted wet retroreflectivity test using the EN 1436 standard as the basis. We also conducted luminance tests for different glass bead refractive indices and line marking thicknesses. RESULTS : 1. Phosphorescent road line markings specimens satisfied the "KS M 6080" standard. 2. In dry retroreflectivity test, phosphorescent road line markings sprayed with glass beads satisfied the national police agency standard ($240mcd/(m^2{\cdot}Lux)$). Wet retroreflectivity test results showed that except for one type of No.1 glass beads, phosphorescent road line markings specimens sprayed with glass beads of one type of No.3 and two types of No.1 satisfied the national police agency standard ($100mcd/(m^2{\cdot}Lux)$). 3. Phosphorescent road line markings had higher retroreflectivity than non-phosphorescent road line markings in the dry condition. 4. Phosphorescent road line markings sprayed with glass beads demonstrated improved luminance. Luminance increased with higher glass bead refractive index and with increased line marking thickness. However, when the thickness crossed a certain threshold, phosphorescence ceased to increase; this is a characteristic of the phosphorescence phenomenon. CONCLUSIONS : Visibility across short distances can be ensured when phosphorescent road line markings are sprayed with glass beads, because of the retroreflection phenomenon. It is also possible to ensure far visibility using phosphorescent road line markings.

• 한국도로학회논문집
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• 제18권6호
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• pp.145-152
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• 2016

OBJECTIVES : Visibility at night can be improved by using retroreflection for short distances and phosphorescent line markings for long distances. In this study, we analyzed the characteristics of the phosphorescent line marking through a laboratory luminance test. Field performance analysis was performed through tests conducted on the road. We also examined the luminance measurement methods using the digital image obtained during the phosphorescent visibility evaluation. METHODS : In this study, the laboratory luminance test of the phosphorescent line marking was conducted using seven specimens to characterize the luminance changes according to the type of the glass beads, the thickness of the phosphorescent line marking, and the brightness and irradiation time of the light source. Phosphorescent and general line markings were made at 150 m to investigate the field luminance performance. A preliminary review of the luminance measurement methods was made using a digital image from a digital single-lens reflex (DSLR) camera. The measured luminance ratio of the general and the phosphorescent line markings was compared with the calculated luminance ratio using luminance analysis. RESULTS : Through the laboratory luminance test, it was seen that the change in luminance, which corresponds to the brightness of the light source, appears large but the influence of the thickness and irradiation time is low. The field performance test of the phosphorescent line marking conducted on the road involved measuring the luminance on the day the marking was made and 7 days after the marking was made. The luminance was found to be $190mcd/m^2$ at 30 min after sunset and approximately $10-12mcd/m^2$ 4h after sunset. The results of the luminance test were captured using a digital image for each time group. The luminance ratio of the phosphorescent line marking, when compared to that of the general line marking, showed a similar trend within a 13% maximum error. Additionally, when this luminance ratio is compared to the direct field measurement, it could be confirmed that the luminance ratio, as captured in the digital image, showed a similar tendency. CONCLUSIONS : 1) The change in luminance corresponding to the brightness of the light source is significant in comparison with that corresponding to the thickness and the irradiation time. In addition, the results of the field test for the phosphorescent line marking satisfied the phosphorescent fire protection standard. 2) We examined the validity of the luminance measurement method using a digital image and we concluded that the change in the luminance ratio shows a similar tendency in both the cases. The results can form the basis for luminance measurement methodology for the construction and maintenance of phosphorescent line markings.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1996년도 춘계학술대회논문
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• pp.101-109
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• 1996

Mini-mill process which is one of the new steel -marking technologies to be able to produce the hot rolled coils by thin slab caster of ISP(In-Line Strip Production) type, will be completed in the Kwangyang Steel Works of POSCO in August, 1996, SEt-Up Model of finishing mill which consists of 5 stands is the most basic and essential in mini-mill plant. Therefore, the simulation program of Finishing-mill Set-Up model were developed in this research , using new temeprature prediction model, roll gap model and rolling physical model. Using the developed FSU program , pass schedules to produce the strips with target strip thickness of 1.8mm, 2.0mm, 2.3mm, 2.7mm an d3.0mm were also determined respectively.

• 대한토목학회논문집
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• 제39권4호
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• pp.513-521
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• 2019

본 연구의 목적은 지하철 이용자의 지하철 표지 여백에 대한 특성의 군집그룹별 선호도를 파악하는 것이다. 세부적으로 성별, 연령 등의 특성에 따라 지하철 표지 여백에 대한 특성을 다양하게 디자인하는 개념을 도입하는 것을 목적으로 한다. 본 연구는 지하철 표지 여백에 대한 특성의 선호도를 조사하고 전체그룹과 군집그룹별 선호도를 분석하였다. 선호도 조사를 위해 설문조사를 실시하였으며, 선호도 분석을 위해 군집분석을 실시하고 전체그룹과 군집그룹의 인구통계학적 분석과 컨조인트 분석을 실시하였다. 선호도 조사를 위한 지하철 표지 여백에 대한 특성의 속성은 상하여백, 측여백, 테두리선 여백, 화살표 두께, '역명'과 '호선번호' 순서로 설정하였다. 선호도 분석 결과는 다음과 같다. 전체그룹에서 속성의 중요도는 테두리선 여백, '역명'과 '호선번호' 순서, 측여백, 상하여백, 화살표 두께 순으로 나타났다. 군집그룹은 총 3개의 그룹으로, 1군집은 지하철을 거의 매일, 일주일에 3~4회 이용하는 여성으로, 글자의 1/2 측여백을 선호하는 것으로 나타났다. 2군집은 60대 이상의 지하철 표지를 불편하다고 생각하는 이용자로, 테두리가 없는 것과 '역명'+'호선번호' 순서를 선호하는 것으로 나타났다. 3군집은 20대와 30대의 남성으로, 글자의 1/5 테두리선 여백과 얇은 화살표 두께를 선호하는 것으로 나타났다. 결론은 다음과 같다. 첫째, 지하철 표지 여백에 대한 특성을 일관성 있게 디자인 해야하지만, 특정지역 혹은 노선에 대해서 성별, 연령별, 지하철 이용횟수에 따라 다양하게 고려할 필요성이 제시되었다. 둘째, 특정지역 혹은 노선에 따라서는 지하철 표지 여백에 대한 특성의 표지를 표준화된 한 가지 유형이 아닌 두 가지 이상의 유형의 디자인이 가능함을 보여주었다.