• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제29권3호
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• pp.29-36
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• 2023

Purpose: The purpose of this study is to find out whether the color change of the LED light source has a significant effect on the beta wave activity of EEG in the learning state. Methods: The subjects of the experiment were 20 male and female college students between the ages of 19 and 25 who routinely perform their studies. In the created learning environment, the EEG change according to the change in the lighting color was measured while solving the Mensa thinking ability problem while sitting on a desk with LED lights installed on the top and a chair with a footrest to stabilize the legs. The light source consisted of 3 ready-made colors and 6 newly created colors. A total of 9 color light stimuli were given for 2 minutes each, and the EEG change of the subject was observed. After the experiment, the correlation was analyzed based on the mid-beta wave data recorded on the QEEG according to the color change of light and the Mensa problem score. Results: It was found that the activation of mid-beta waves was stimulated in the temporal lobes (T5, T3, T6, T4) and occipital lobes (O1, O2) of all subjects who focused on solving Mensa thinking problems. As a result of comparing the top 20% and the bottom 20% of problem solving scores, the upper group had no effect of lighting, while the lower group showed increased beta wave activity in response to color light stimulation in the order of T4, T6, and T5. Implications: It was confirmed that the color of light that activates the middle beta wave varies greatly depending on the subject's attention and learning ability, and it is judged that the color of light including the green wavelength is helpful in activating the middle beta wave in the group with low learning ability.

• 접착 및 계면
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• 제13권1호
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• pp.31-37
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• 2012

본 연구는 UV-LED 경화형 칼라코팅에 대한 경화특성에 관한 것으로, 특히 UV-LED 파장(365, 395, 405 nm), 불활성 기체, 증감제 및 Dual curing에 따른 경화성을 평가하였다. 광경화 과정과 코팅 도막의 Film-air (FA) interface와 Film-substrate (FS) interface에서 존재하는 미반응 아크릴레이트에 대한 평가는 Photo-DSC와 FT-IR/ATR을 이용하여 각각 조사하였다. Photo-DSC 측정 결과 발열량과 전환율은 405 nm UV-LED를 이용한 코팅 시스템의 경우가 395 및 365 nm UV-LED를 사용한 경우보다 높게 나타났다. UV-LED 경화형 시스템은 전반적으로 Film-substrate (FS) interface의 경화도가 높은 것으로 나타나 후막경화가 우수함을 알 수 있었으나, Film-air (FA) interface의 표면 경화도는 산소저해 현상으로 인해 매우 낮음을 FT-IR/ATR 결과를 통해 확인하였다. 이러한 낮은 표면 경화도는 불활성 기체인 질소를 사용하거나 Dual curing 방법을 도입함으로써 개선할 수 있었다.

• 한국인쇄학회지
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• 제28권1호
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• pp.65-75
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• 2010

Environmentally friendly, stencil and screen printing for cost-effective for maskless. In this study, UV -LED light source for the dispersion characteristics and high competence photoresist coating was prepared. Wavelength of 365nm UV-LED exposure device using the maskless lithography, 1.7kgf/$cm^2$ $2600mmH_2O$ the injection pressure and the suction pressure by using a dry photoconductor symptoms were dry emulsion on the market as a result, curing properties and adhesion, hardness, solvent resistance and excellent reproduction of fine patterns and ecological stencil technology was available and could be confirmed as a possibility.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.479-482
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• 2006

The absorption coefficient and backscattering properties of phytoplankton were calculated from the Mie theory. Given a simple case that phytoplankton and mineral particles are the only constitutions in seawater, the reflectance $b_b({\lambda})/[a({\lambda})+b_b({\lambda})]$was analyzed. Then the chlorophyll concentrations were estimated from remote sensing OC2 algorithm. The results show that reflectance in short wavelength region is more sensitive to the Chl variation; High mineral concentrations in seawater have significant influence on the reflectance spectrum; the existence of high mineral concentration may result in the mistake in chlorophyll estimation from OC2 algorithm.

• 제어로봇시스템학회논문지
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• 제19권12호
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• pp.1081-1088
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• 2013

Hyperspectral cameras acquire reflectance values at many different wavelength bands. Dimensions tend to increase because spectral information is stored in each pixel. Several attempts have been made to reduce dimensional problems such as the feature selection using Adaboost and dimension reduction using the Simulated Annealing technique. We propose a novel material detection method that consists of four steps: feature band selection, feature extraction, SVM (Support Vector Machine) learning, and target and specific region detection. It is a combination of the band ratio method and Simulated Annealing algorithm based on detection rate. The experimental results validate the effectiveness of the proposed feature selection and band ratio method.

• 한국재료학회지
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• 제27권6호
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• pp.312-317
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• 2017

In the construction of a white LED, the region of the red emission is a very important factor. Red light emitting materials play an important role in improving the color rendering index of commercial lighting. These materials also increase the color gamut of display products. Therefore, the development of novel phosphors with red emission and the study of color tuning are actively underway to improve product quality. In the present study, heuristic algorithms were used to search for phosphors capable of increasing the color rendering index and color gamut. Using a heuristic algorithm, the phosphors that were identified were $SrGe_4O_9:Mn^{4+}$ and $BaGe_4O_9:Mn^{4+}$. Emission spectra study confirmed that these phosphors emit light in the deep red wavelength region, which can fulfill the requirement for the improvement in color rendering index and color gamut for a white LED.

• 전기전자학회논문지
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• 제23권2호
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• pp.487-494
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• 2019

본 논문에서는 토양에 침투하는 미세먼지의 영향을 피하여 폐쇄된 공간에서 물과 배양액을 이용하는 IOT(Internet of Things) 기반의 수경재배 식물공장을 제작하고, PLC(Programmable Logic Controller) 제어 방법을 제안한다. 제작된 수경재배 식물공장은 터치스크린과 스마트폰을 통하여 산소의 농도, 양액의 농도, 온도, 습도의 정도를 모니터링 하고, 히터 및 쿨러제어, 환풍기 및 제습장치 제어, LED의 파장 등을 사용하여 식물이 적정한 환경에서 성장할 수 있도록 제어한다.

• 한국균학회지
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• 제47권1호
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• pp.63-73
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• 2019

표고 균사체의 갈변은 균사배양체의 오염과 수분 손실을 방지하는데 매우 효과적이다. 광과 광 파장이 표고 산조701호 품종의 균사체 갈변에 미치는 영향과 갈변 균사의 특징을 이해하고자 하였다. 표고 균사체를 감자한천배지에서 암배양한 후 적색, 녹색, 청색의 색 셀로판 필터를 덥거나, 원적색(far-red), 적색, 녹색, 청색의 light emitted diode (LED)를 매일 14시간씩 40일간 비춘 후 균사배양체의 갈변 면적 비율(갈변율)과 갈변 균사의 특징을 조사하였다. 파장대 범위가 300~1,100 nm인 백색 형광등 빛은 세 가지 각각의 색 셀로판을 통과하면서 360~1,022 nm로 좁아졌고 각 파장별로 photosynthetic photon flux density (PPFD)는 42~71%가 감소하였다. 형광등 빛 처리로 균사체의 갈변율은 면적비율로 평균 64%였으나, 빛을 받지 않은 균사체의 갈변율은 5%에 지나지 않았다. 광 파장별로 표고 균사체의 갈변율은 원적색에서 0.02%. 적색에서 1.5%, 녹색에서 53.8%, 청색에서 57.3% 였다. 그리고 흰색의 미갈변 표고 균사는 세포벽이 $1{\mu}m$ 미만으로 얇고 원형질이 들어찬 생장하는 것이었다. 이에 반하여, 갈변층의 균사는 세포벽이 $2-4{\mu}m$으로 두껍고 세포 내용물이 없는 죽은 것으로 탄력이 없이 단단한 부정형의 구조체였다. 결론적으로 녹색~청색 파장의 빛으로 촉진된 표고 균사의 갈변층은 죽은 조직이지만 그 아래 내부 활력 균사체를 보호하는 중요한 기능층이었다.

• Journal of Information Display
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• 제11권1호
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• pp.24-27
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• 2010

A novel stereo 3D LCD for passive interference filter glasses is presented. A demonstrator based on a standard 120Hz LCD was set up. Stereoscopic image separation was realized in a time-sequential mode using a LED-based scanning backlight with two complementary spectra. A stereo brightness of 3 cd/$m^2$ and a channel separation of 30:1 were achieved.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.385-387
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• 2003

We have fabricated a new-type high-brightness phosphor consisting of a sol-gel derived glass with finely dispersed semiconductor nanocrystals. It is possible to obtain visible light of any wavelength with a single UV irradiation. The glass firmly adheres to a glass substrate. Therefore it can easily be used for developing devices.