• Ecology and Resilient Infrastructure
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• v.6 no.3
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• pp.171-177
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• 2019

The hyperspectral images can be analyzed in more detail compared to the conventional multispectral images so they can be used for analyzing surface properties which are difficult to detect. Therefore, the purpose of this study is to obtain information on river environment by using actual depth data and drone-based images. For this purpose, this study acquired the image values for 100 points of 1 survey line using drone-based hyperspectral sensors and analyzed the correlation in comparison with the actual depth information obtained through ADCP. The ADCP measurements showed that the depth tended to get deeper toward the center and that the average water depth was 0.81 m. As a result of analyzing the hyperspectral images, the value of maximum intensity was 645 and the value of minimum intensity was 278, and the correlation between the actual depth and the results of analyzing the hyperspectral images showed that the depth increased as the value of maximum intensity decreased.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.136-136
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• 2003

• The korean journal of orthodontics
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• v.27 no.5 s.64
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• pp.781-789
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• 1997

The purpose of this study was to evaluate the effects of fluoride relasing orthodontic sealant on the shear bond strength of light-and chemical-cured orthodontic rosins, to compare the shear bond strenth with light-and chemical-cured orthodontic resins, and to identify the changes of shear bond strength by rebonding in vitro. The brackets were divided into eight groups. Each group of metal brackets had different bonding mechanisms with adhesives. Group A : Transbond only Group B : Mono-Lok 2 only Group C : Light cured FluoroBond+Transbond Group D : Light cured FluoroBond+Mono-Lok 2 Group E : Transbond only(rebonded) Group F : Nomo-Lok 2 only(rebonded) Group G : Light cured FluoroBond+Transbond(rebonded) Group H : Light cured FluoroBond+Mono-Lok 2(rebonded) 65 extracted human premolars were prepared for bonding and 65 metal brackets for each group were bonded to prepared enamel surfaces of buccal surfaces as the above prescription. 24 hours bonding after, the Instron universal testing machine was used to test the shear bond strength of metal brackets to enamel. After debonding, same kind of metal brackets for each group were rebonded to prepared enamel surfaces of buccal surfaces to test the shear bond strength at the rebonding to enamel. Statistical analysis of the data was carried out Student's t-test ANOVA test, and Scheffe test using $SPSS/PC^+$ The results were as follows : 1. The order of shear bond strength was Group B(11.84MPa), Group A(10.75MPa), Group, D(9.69MPa), and Group C(9.39MPa)in lst bonded groups. 2. The order of shear bond strength was Group E(7.40MPa), Group G(6.48MPa), Group F(5.89MPa), and Group H(5.15MPa) in rebonded groups. 3. The shear bond strength of chemical cured orthodontic rosins had higher than that of light-cured orthodontic resins in all groups, but there was no statistical significance between groups(P>0.05). 4. In rebonded groups, the shear bond strength of light cured orthodontic rosins had higher than that of chemical cured orthodontic resins, but there was no statistical significance between groups(P>0.05). 5. The shear bond strength of all rebonded groups progressively decreased than that of 1st bonded groups, and there was statistical significance between groups(p<0.05, p<0.001).

• Journal of the Korean Institute of Gas
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• v.12 no.4
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• pp.63-68
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• 2008

This paper describes about the simulation and the experimental results of optical cavity with curved mirror surface and vertical mirror surface to improve the light intensity and efficiency of the optical sensors. When we use the vertical mirror surface, the distribution of light reached to the filter surface of detector shows an elliptical shape. Whereas, the curved mirror surface focuses the light into circular shape. Therefore, due to focusing effects in case of using curved mirror surface, the light intensity per unit area has been improved. Consequently, the output voltage of gas sensor has been expected to increase. Based upon the simulation, the experiment of gas sensor has been conducted with $CO_2$ gas from 0ppm to 2,500 ppm at 250 ppm step and $25^{\circ}C$, 45%R.H. ambient. The output voltage of gas sensor that has a curved mirror surface increases approximately 200 mV than that of vertical mirror surface.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.1
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• pp.85-91
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• 2004

The purpose of this study was to observe in vitro pulp chamber temperature rise during composite resin polymerization with various light-curing sources. The kinds of light-curing sources were plasma arc light(P), low heat plasma arc light, traditional low intensity halogen light, low intensity LED(L-LED), and high intensity LED(H-LED). Temperature at the tip of light guide was measured by a digital thermometer using K-type thermocouple. Occlusal cavities$(2{\times}2{\times}1.5mm)$ were so prepared in extracted human premolars as to the remaining dentin thickness was 1mm. Dentin adhesive was applied to all cavities. Experimental groups consisted of no base group, ionomer glass base group, and calcium hydroxide base group. Temperature before and after resin filling was measured. Temperature at the light guide tip was the highest with P and the lowest L-LED. Temperature before resin filling was the highest with H-LED and the lowest with L-LED. Temperature after resin filling was the highest with H-LED and the lowest with L-P and with L-LED. The lining of base partially reduced the temperature rise.

• The korean journal of orthodontics
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• v.40 no.1
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• pp.27-33
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• 2010

Objective: The need to bond orthodontic brackets onto various alloys has increased because of the increasing demand for adult orthodontic treatment. This study tried to evaluate the shear bond strength between gold alloy and metal bracket using light emitting diode (LED) light curing after metal primer and silicoating surface conditioning. Methods: Half of the type III gold alloy plates were treated with sandblasting with aluminum oxide and metal primer containing 4-META. the other half were treated with silica and silane. Metal brackets were bonded with Transbond XT light curing adhesive on these plates and shear bond strength were evaluated 1 hour, 6 hours, and 24 hours later. The differences of shear bond strength between groups were evaluated with two-way ANOVA. Results: The results showed higher bond strength in the silicoating group and a tendency of bond strength increase over time. Conclusions: When using LED curing lights for metal bracket bonding to alloy surfaces, long curing time and silicoating can produce a reliable bonding strength.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.304-311
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• 2020

The purpose of this study is to change plant growth according to the light quantity of LED light source and to standardize plant factories technology according to the optimal LED light range. Growth was relatively stable at the 1,400 lx and 1,600 lx intensities, and growth continued with increasing light intensity, but growth slowed down with growth without leaves (Ed- I don't understand). The growth characteristics at 400 lx to 800 lx were sustained to some extent during the experimental period, but the growth of the larvae was maintained until the 7th day and the growth of leaves was not developed. From 1,000 lx to 1,400 lx, brightness, leaf growth and daily growth increased, and the growth cycle exhibited a repeating cycle of growth and slowdown. In addition, 1,600 lx and 1,800 lx showed similar growth to that at 1,400 lx, but leaf growth was high. However, at 1,800 lx, the growth was slightly higher than at 1,400lx and it slowed down over time. In addition, the stronger the light, the higher the temperature around the plant and the greater the dryness of the leaves due to the heat emitted from the light source.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1749_1750
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• 2009

본 논문에서는 태양광 발전 시스템에 대한 강인 디지털 재설계 방안에 대해 다루고자 한다. 다른 신재생에너지 시스템과 마찬가지로 태양광 발전 시스템은 비선형 동적 방정식으로 구성되며, 주위 환경의 영향에 민감하게 반응한다. 이에 대한 해석을 위해 본 논문에서는 강인 퍼지 이론을 이용하여 시스템의 비선형성 및 불확실성을 해결하게 된다. 또한, 디지털 재설계 이론을 바탕으로 하여 디지털 기기 사용에 적합한 환경을 구성할 수 있는 계기를 마련하게 된다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.85-85
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• 2022

영농형 태양광발전은 태양의 일사량을 전기발전과 영농에 공유하는(solar-sharing) 방식이다. 본 연구는 신재생에너지의 활용의 극대화를 위하여 추적식 영농형 태양광발전시스템을 구축하고 시설하부에서 일정 기간 재배중인 작물의 하부 환경과 생육을 조사하여 영농형태양광 하부작물개발을 위한 기초자료를 확보하고자 하였다. 구축한 추적식 영농형 태양광발전시스템은 4열 6단의 24장 모듈(8m × 6m)을 가지며, 발전시설 중심축 기둥 간 중심간격 14m로 단일지주식 스크루 공법으로 순천대학교 부속농장 답작포(순천시 죽평리)에 설치하여 하부 환경과 하부작물의 생육을 조사하였다. 태양광발전시설 하부작물의 생육을 조사하기 위하여 순천 농협육묘장에서 벼(신동진)를 육묘하여 2022년 6월 16일 이앙하였다. 태양광발전시스템 하부 지역을 4방위 방향에 따라 강음영(중심축으로부터 1~3m), 중음영(5m), 약음영(7~9m) 구역으로 설정하여 생육을 조사한 결과, 방위에 따른 초장은 남쪽에서 음영간 차이가 상대적으로 낮게 나타났으며, 1번기 태양광 발전시설에 의하여 음영이 중첩된 2번기 시설의 동쪽에서 대조구 대비 초장이 상대적으로 낮은 경향을 나타내었다. 음영강도에 따른 초장은 대체로 강음영구에서 낮게 나타났으며, 약음영구로 갈수록 높게 나타났다. 엽수는 방위에 따라서, 그리고 음영의 강도에 따른 차이가 초장에 비하여 작게 나타났다. 출수기의 경우 방위별로는 남쪽에서 음영별 차이가 작게 나타났으며, 음영강도에 따라서 차이를 보였다. 또한 태양광시설 하부에 데이터수집장치(Model 1650, Spctrum Technonogies, USA)를 설치하여 음영에 따른 토양전도도, 토양함수량, 토양온도, par light 등 생육환경을 조사, 비교하였다.

• The Optical Journal
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• v.11 no.6 s.64
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• pp.49-59
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• 1999

지난 호에 있어서 태전위부 박사(송하전기산업주식회사 광디스크개발센타)의 '광메모리' 강의(한$\cdot$일 광학산업 기술협력 세미나)를 연재한다. 9월호에는 광메모리 매체의 역할, 광디스크 드라이브 시스템의 구성, 위상변화 광오버라이트 메모리의 원리, 위상변화재료를 다뤘다. 이번 호에는 위상변화 광디스크의 구성재료, 위상변화 공디스크의 오버라이트 특성, 위상변화 광디스크와 광자기디스크의 비교, DVD를 실현하는 기술 등을 소개한다.