녹색광을 이용한 반사형 광용적맥파측정기의 주변광 간섭시 신호측정

장기영,고현철,이정직,윤영로,Chang, K.Y.,Ko, H.C.,Lee, J.J.,Yoon, Young Ro 대한의용생체공학회 2014 의공학회지 Vol.35 No.5

The purpose of this study is to verify the utility of reflected photoplethysmography sensor using two green light emitting diodes that influenced by ambient light. Recently it has been studied that green light emitting diode is suitable for light source of reflected photoplethysmography sensor at low temperature and high temperature. Another study showed that, green light is better for monitoring heart rate during motion than led light. However, it has a bad characteristic about ambient light noise. To verify the utility of reflected photoplethysmography sensor using green light emitting diode, this study measures the photoplethysmography signal that is distorted by ambient light and will propose a solution. This study has two parts of research method. One is measurement system that composed sensor and board. The sensor is made up PE-foam and Non-woven fabric for flexible sensor. The photoplethysmography signal is measured by measurement board that composed high-pass filter, low-pass filter and amplifier. Ambient light source is light bulb and white light emitting diode that has three steps brightness. Photoplethysmography signal is measured with lead II electrocardiography signal at the same time and it is measured at the finger and radial artery for 1 minute, 1000 Hz sampling rate. The lead II electrocardiography signal is a standard signal for heart rate and photoplethysmography signal that measured at the finger is a standard signal for waveform. The test is repeated 3 times using three sensor. The data is processed by MATLAB to verify the utility by comparing the correlation coefficient score and heart rate. The photoplethysmography sensor using two green light emitting diodes is shown better utility than using one green light emitting diode and red light emitting diode at the ambient light. The waveform and heart rate that measured by two green light emitting diodes are more identical than others. The amount of electricity used is less than red light emitting diode and error peak detectability factor is the lowest.

브라켓 접착시 광중합방식에 따른 전단결합강도와 파절양상 비교

신재호,임용규,이동렬 대한치과교정학회 2004 대한치과교정학회지 Vol.34 No.4

기존의 가시광선 중합기와 비교해서 plasma arc light와 LED 방식의 중합기를 이용해 브라켓을 치아표면에 접착한 후 탈락시키는 실험을 시행해 각각의 중합방식별로 전단결합강도와 접착파절양상을 비교함으로써 임상에서의 유용성을 평가하고자 하였다. 교정치료를 위해 발거한 상, 하악 소구치 60개를 윈통형의 레진블록에 매몰하여 시편을 제작하였다. 광중합형 접착레진인 Transbond XT를 이용하여 광중합 방식별로 조건(가시광선 중합기는 40초, LED방식의 중합기는 20초, 그리고 plasma arc light 방식의 중합기는 3초) 에 따라 브라켓을 접착한 후 만능물성실험기로 전단결합강도를 측정하고 브라켓 기저면을 광학현미경으로 관찰해 접착파절양상을 관찰하여 다음과 같은 결과를 얻었다. 1. 가시광선 중합방식과 LED 중합방식으로 중합시킨 군간에 전단결합강도의 유의성 있는 차이는 없지만 plasma arc Light 방식으로 중합시킨 군은 앞의 두 군에 비해 유의성이 있게 작은 값을 나타내었다(p>0.05). 2. 가시광선 중합방식으로 중합한 군과 LED 방식을 이용한 군에서는 파절양상이 거의 유사하게 나타났다. 두 군 모두 잔류접착제가 치아면에만 있는 경우가 제일 적은 비율을 보였으며 브라켓 기저면에 50% 이상의 접착제가 남아 있는 양상이 더 큰 비율을 보였다. 3. Plasma arc light 로 중합시킨 경우에는 접착제가 브라켓 기저면에 50% 이하로 남아있는 양상이 큰 비율로 나타났으며 잔류 접착제 전체가 치아면에 남아 있는 경우는 15%였다. 이상의 실험결과 plasma arc light를 이용한 중합 방식이 가시광선이나 LED 방식을 이용한 중합 방식에 비해 유의성 있게(p>0.05) 낮은 전단결합강도를 보였으나 세 방식 모두 임상적으로 사용하기에 충분한 전단결합강도를 보여 유용하게 사용할 수 있음을 알 수 있었다. The purpose of this study was to evaluate the clinical effectiveness of a plasma arc light and light emitting diode (LED), compared with shear bond strength and the failure pattern of brackets bonded with visible light in direct bonding. Brackets were bonded with Transbond XT to 60 human premolars embedded in the resin blocks according to different light-curing methods. Then, the shear bond strength of each group was measured using a universal testing machine (Instron) and the adhesive failure pattern after debonding was visually examined by light microscope. The results were as follows: 1. The shear bond strength showed no significant difference between the visible light and light emitting diode, but the plasma arc light exhibited a significantly lower shear bond strength compared with the visible light and light emitting diode. 2. In the visible light and light emitting diode, adhesive failure patterns were similar. Bond failure occurred more frequently at the enamel-adhesive interface. 3. The bonding failure of brackets bonded with plasma arc light occurred more frequently at the bracket-adhesive interface. The results of this study suggest that plasma arc light, light emitting diode and visible light are all clinically useful in the direct bonding of orthodontic brackets.

Therapeutic application of light emitting diode: Photo-oncomic approach

Oh, Phil-Sun,Jeong, Hwan-Jeong Elsevier 2019 Journal of photochemistry and photobiology. B, Bio Vol.192 No.-

<P><B>Abstract</B></P> <P>As a new light source, light emitting diode (LED) with high brightness and lower cost has been rapidly developed in medical application and light therapy. LED phototherapy can activate target cells with appropriate power and adequate energy density. This review provides general information on therapeutic applications of blue, green, yellow, red, and infrared LED in medical treatments for various physical abnormalities and on bio-imaging. The bio-imaging system is improved by decreasing the number of microscopes apparatuses including neutral-density filter, excitation filters and mechanical shutters. The numbers of excitation photons are increased and the fluorescent excitation efficiency is improved at cellular level. In the target tissue, the therapeutic effect of LEDs is dependent on incident photons irrespective of the system used to generate these photons. Photomodulated light from LED device is delivered in pulsed mode with specific pulse sequences and time. Too low or too high dose of energy may be ineffective at all. Clinical applications of LED light depending on different wavelengths are summarized. The author's photo-oncomic experiments using a specific blue light emitting diode were introduced, showing that blue LED possessed anti-proliferative and anti-metastatic abilities in cancer cells and mice. As a promising light source, photo-oncomic approach of blue LED could be applied to treat cancers and inflammatory diseases.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Therapeutic applications of visible light in medical treatments were introduced. </LI> <LI> The bio-imaging system using LEDs is improved by decreasing the number of microscopes apparatuses. </LI> <LI> Therapeutic effect of LEDs is dependent on incident photons in the target tissue. </LI> <LI> The author's photo-oncomic experiments using a specific blue LED were introduced. </LI> </UL> </P>

Study on Simulation Design of Light Emitting Diode Luminaires for 100 W Safety Street Lighting

Shin, Ik-Tae,Lee, Se-Il,Yang, Jong-Kyoung,Park, Dae-Hee,Lee, Dong-Jin The Korean Institute of Electrical and Electronic 2010 Transactions on Electrical and Electronic Material Vol.11 No.3

Optical analysis is necessary to optimize light emitting diode (LED) safety street lighting. In this study, optical analysis was conducted for 100 W LED safety street lighting. Experimental research on such a single LED was the first undertaken. Simulation modeling based on the optical properties of the single LED has compared between average road illuminances and has them analyzed with Korean Industrial Standards for LED safety street lighting (KS C7658:2009). The simulation results demonstrated that the illumination performance (average road illuminance) was 75.3 lx at a height of 4 m and an area of $32\;m^2$, 45.25 lx at a height of 5 m and an area of $72\;m^2$, and 30.05 lx at a height of 6 m and an area of $128\;m^2$. 100 W safety street lighting (model CE180-ST-OS) designed by simulation was also compared between product and 100 W simulation modeling, and error rates averaged 5.6%. The 100 W LED safety street lighting base designed in simulation modeling was proven by comparison experiments. Through the simulations and the corresponding analysis, it was found that the tested 100 W LED safety street lamp had reasonable performance. The design method for LED safety street lamps has been summarized based on the optical analysis.

발광다이오드(LED) 조명을 이용한 녹조 구멍갈파래U(lva pertusa)의 생장

권천중 ( Chun Jung Kwon ),최창근 ( Chang Geun Choi ) 한국수산과학회 2013 한국수산과학회지 Vol.46 No.5

To determine an efficient growth system for algal cultivation and to develop adequate culture system utilizing LED light, we investigated the effects of fluorescent and light emitting diode (LED) light source on the growth of Ulva pertusa . U . pertusa was cultured at 17 ºC under a light intensity of 35 μmol photons m-2s-1 and a 10L:14D photoperiod using either fluorescent or LED lamps. After 1 week of incubation under the same environmental condition, the length and width of Ulva pertusa grown under LED light were 1.5- and 1.9-fold greater, respectively,than the length and width of algae grown under fluorescent light. After two weeks, length and width were 2.6-and 2.0-fold greater, respectively, in algae grown under LED light. Total length and width of Ulva pertusa after three weeks of incubation were 1.7- and 1.2-fold greater in algae grown under LED light than those grown under fluorescent light. Therefore, the LED light induced significantly higher growth of Ulva pertusa than fluorescent light.

의료용 고 조도 발광 다이오드 헤드라이트

이의형,주영구,정재헌,박승현,이계선 한국물리학회 2011 New Physics: Sae Mulli Vol.61 No.2

High-brightness light-emitting diodes have been used to develop high-illuminance headlamps for medical applications. There headlamps provide various advantages, such as high illuminance, long lifetime, reduced infrared light, extended operation time with a battery and light weight. A 3-W light-emitting diode (LED) was employed to achieve the high-performance medical headlamps. The optical design included two lenses for high energy transmission and high illuminance. The LED headlamp show 42,000 lux with a spot diameter of 80 mm at a distance of 300 mm. For comparison,a 5-W LED was also used to obtain a high-illuminance headlamp. However, the large divergence angle and the large spot size of the 5-W LED limit the illuminance to 31,000 lux with increased heat dissipation. Thermal images of the heat sinks indicated that the temperature of the headlamp using the 3-W LED was below 50℃, which is suitable for medical applications. 의료용 고조도 헤드라이트 개발을 위해 고휘도 발광 다이오드를 사용하였다. 고휘도 발광 다이오드는 고조도, 긴 수명, 적은 양의 적외선, 배터리에 의한 구동 등의 여러 가지 장점을 제공한다. 의료용 고조도 헤드라이트 개발을 위해 3 W light-emitting diode(LED)를 사용하였고, 광학 디자인은 높은 에너지 전송과 높은 조도 달성을 위해2개의 렌즈를 사용하였다. LED 헤드라이트는300 mm 떨어진 위치에서 스폿 직경이 80 mm, 조도가 42,000 lux 이다. 비교를 위해 5 W LED 도 고조도 헤드라이트 개발에 사용하였다. 그러나 5 W LED 는 큰 발산각과 큰 스폿 직경으로 인해 조도가 31,000 lux로 제한되며, 방열도 문제가 되었다. 3 W LED 헤드라이트의 온도는 55 ℃ 이하여서 의료용 장비로 적합하다.

05 포스터 발표 : 자연생태 환경 분야(PN) ; 식물공장 시스템내 광환경 제어가 적축면 상추 생장에 미치는 영향

허정욱 ( Jeong Wook Heo ),김동억 ( Dong Euk Kim ),이광재 ( Kwang Jae Lee ),강동현 ( Dong Hyeon Kang ),이시영 ( Si Young Lee ),신현만 ( Hyun Man Shin ),허윤선 ( Yoon Sun Huh ),이기열 ( Ki Yeol Lee ),김태중 ( Tae Jung Kim ),김숙종 ( 한국환경농학회 2014 한국환경농학회 학술대회집 Vol.2014 No.-

Plant factory, which considered as a novel plant production system preparing for the climate changes such as a global warming or raining, is an attractive year-round production technique of leafy plants regardless of place or season. The environmental factors of air temperature, relative humidity, nutrient, CO2 concentration, light intensity or quality inside the factory system influencing on growth have been reported. In this study, effects of light-environmental control of quality or intensity were investigated on growth of red curly lettuce ( Brassica rapa) seedlings with different four growth ages (0, 10, 20, and 30 days-old after transplanting) inside the factory system. ‘Tukksum’ red-curly lettuce which developed two true leaves was used as a plant material, and the seedlings were cultured under nutrient solution of 1.5 ds m-1 EC and 5.8 pH for 10 days after light exposure of 50, 100 or 230 μmol m-2 s-1. Light-emitting diodes of Red, blue plus red, and blue plus white were used, and fluorescent light was considered as a control. In 0 day-old seedlings after transplanting, dry weight and number of leaves under blue plus red light of 50 μmol m-2 s-1 light intensity for 10 days increased 28 and 19% comparing with the control, respectively. Increasing of fresh and dry weights in 30 days-old seedlings was significantly stimulated by blue plus red and red light. However, leaf pigmentation was inhibited by the red light regardless of the different growth ages and promoted by the mixture lights. Under 230 μmol m-2 s-1 light intensity, number of leaves, fresh and dry weights were greater by mixture-light exposure on 20 days-old seedlings. On 30 days-old seedlings, increment of dry and fresh weights was also affected by the mixture light. Leaf pigmentation was significantly inhibited by the red light regardless of the different light intensities in all the growth ages. Higher growth and pigmentation could be achieved at 20 and 30 days-old seedlings cultured under the mixture lights of blue, red, or white. It is concluded that light intensity should be controlled according to growth ages for growth and pigmentation, but rather stable control during culture period, and monochromic red is not suitable for leaf pigmentation of red curly lettuce in plant factory system.

국내육성계통 팔레놉시스 줄기절편배양에서 LED 조사에 의한 원괴체 생육 및 식물체 대량생산

고정애 ( Jeong Ae Ko ),권아름 ( A Reum Kwon ),박종훈 ( Jong Hoon Park ) 전북대학교 농업과학기술연구소 2014 농업생명과학연구 Vol.45 No.1

팔레놉시스 국내육성계통 스프링댄스계(KV600×07PN50, 11-16)의 줄기절편체의 원괴체 유도 및 증식, 소식물체 대량 생산에 미치는 LED 효과를 조사하기 위해 0.5mg·L-1 TDZ, 50mg·L-1 coconut water 가 첨가된 1/2MS 배지 또는 Hyponex 배지에 치상하여 LED 광원이 부착된 생장상에서 배양하였다. 대조구인 형광등을 비롯 적색, 청색, 적색+ 청색, 녹색 및 백색의 LED 광원에서 배양 60일 후 조사한 결과 PLB 유도(5.4개) 및 증식(17.0개), 소식물체 증식(5.6개)이 Green 광원에서 신속하게 분화되어 효과적이었다. 기내소식물체의 발육단계별 생육에 미치는 LED 효과에서 1.0-1.5cm 미만 크기의 소식물체는 Blue 광원하에서 엽수가 3.1개로 가장 많이 분화되었고, 엽장은 Red 광원(0.8cm), 엽폭은 White 광원하(0.6cm)에서 가장 빠르게 생장하였으나 두 광원간에 유의적 차이는 없었다. 근계 발달과 추가적인 PLB 증식에는 Red와 Blue의 혼합광원이 가장 양호하였다. 1.6-2.0cm 크기의 기내소식물체의 경우 초장은 White 광원하에서 4.4cm로 가장 길었고 엽수는 Blue 광원하에서 4.9개가 분화되었다. 다신초 형성에는 Green 광원하에서 2.1개로 가장 많았고 생체중은 형광등하에서 4.6g으로 가장 무거웠다. 엽록소 함량은 엽내 SPAD 값이 차이가 있어 적색과 청색혼합광원에서 50.9로 가장 많았으며 Green 광원하에서 33.4로 가장 적었다. In order to investigate the effect of light emitting diode(LED) lightings on PLB induction, multiplication and mass production of plantlets, stem segments from in vitro seedlings of Phalaenopsis domestic line(KV600×07PN50, 11-16) were cultured on 1/2MS with 0.5mg·L-1 TDZ added 50mg·L-1 coconut water or Hyponex media in the growth chamber contained various LED lights. The rate of PLB induction and multiplication were highest under the green light as 5.4, 17.0, respectively, and number of regenerated plantlets were greatest as 5.8 after sixty days of culture. All plants were grew under various lighting sources of LEDs(red, blue, red+blue, green and white) as well as fluorescent light. The rate of growth were differed according to the lightened kinds of LED and developmental stage of in vitro regenerated plantlets. After sixty days of culture, the number of leaves(blue light, 3.0), the length of leave (red, 0.8cm) and the width of leaves(white, 0.6cm) were effectively observed compare to the other lights in plantlets of shoot length 1.0-1.5cm. However, there is no significantly differences between the red and white lights. The red and blue mixed light were better than other lights in root development and additional propagated multiplication of PLB. Also the shoot length(4.4cm) and the number of leaves(4.9) were obtained in white and blue light, respectively, from the plantlets of shoot length 1.6-2.0cm. The green light was effective in multiple shoot differentiation(2.1) and the fluorescent light was heavy(4.6g) in fresh weight. On the other hand, the SPAD values in the leaves were greatly different between red+blue mixed light(33.4) and green light(50.9).

Theoretical Analysis of the Light Extraction Efficiency of a Light-emitting Diode with a Bottom Photonic Crystal

Dang Hoang Long,In-Kag Hwang,Sang-Wan Ryu 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.1

A light-emitting diode (LED) with a bottom photonic crystal (PC), where the PC was fabricated below the active layer, was theoretically analyzed to obtain its light extraction efficiency. A finitedifference time-domain (FDTD) method was used for the simulation of LEDs with top and bottom PCs, and their light extraction efficiencies were compared. The bottom PC was shown to be effective in increasing the extraction efficiency for a small distance from the PC to the active layer. This superior extraction efficiency was attributed to the large confinement of light between the top surface of the LED and the PC. For the analyzed designs, we theoretically estimated the enhancement of light extraction for various lattice constants, PC thicknesses, ratios of the hole radius to the lattice constant, and distances from the PC to the active layer. The optimized parameters were obtained for the highest light extraction efficiency. A light-emitting diode (LED) with a bottom photonic crystal (PC), where the PC was fabricated below the active layer, was theoretically analyzed to obtain its light extraction efficiency. A finitedifference time-domain (FDTD) method was used for the simulation of LEDs with top and bottom PCs, and their light extraction efficiencies were compared. The bottom PC was shown to be effective in increasing the extraction efficiency for a small distance from the PC to the active layer. This superior extraction efficiency was attributed to the large confinement of light between the top surface of the LED and the PC. For the analyzed designs, we theoretically estimated the enhancement of light extraction for various lattice constants, PC thicknesses, ratios of the hole radius to the lattice constant, and distances from the PC to the active layer. The optimized parameters were obtained for the highest light extraction efficiency.

유기발광다이오드 조명용 유기발광체의 최근 동향

정효철 ( Hyocheol Jung ),이하윤 ( Hayoon Lee ),강석우 ( Seokwoo Kang ),안병관 ( Byeong-kwan An ),육경수 ( Kyoung Soo Yook ),박영일 ( Young-il Park ),김범진 ( Beomjin Kim ),박종욱 ( Jongwook Park ) 한국공업화학회 2016 공업화학 Vol.27 No.5

유기 발광 다이오드(OLED)는 학문 및 산업분야에서 많은 관심을 받고 있다. OLED는 이미 휴대폰과 TV분야에서 상업화에 성공하고 있으며, 조명분야에서는 기존에 사용되어왔던 백열등, 형광등과는 다르게 면발광, 대면적, 초경량, 초박형, 유연성의 특징은 물론 낮은 에너지 사용 등의 차별성을 가지고 있기 때문에 최근 많은 관심을 받고 있다. 본 논문에서는 white organic light-emitting diode (WOLED)에 적용되는 대표적인 형광 및 인광 발광 재료들을 소개한다. 이렇게 선행 연구된 물질들을 이해하고 체계적으로 분류하는 것은 앞으로 새로운 발광 재료를 연구, 개발하는데 큰 도움을 줄 수 있을 것으로 기대된다. Organic light-emitting diode (OLED) has drawn a lot of attention in academic and industrial fields, which has been successfully commercialized in mobile phones and TV’s. In the field of lighting, unlike the existing incandescent or fluorescent lighting, OLED has distinctive qualities such as surface lighting-emission, large-area, lightweight, ultrathin, flexibility in addition to low energy use. This article introduces prominent fluorescent, phosphorescent, and luminescent materials applied to white OLED (WOLED). The understanding and systematic classification of previously studied substances are expected to be greatly helpful for the development of new luminous materials in future.