• Title/Summary/Keyword: Light-emitting Diode

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Variation of glucosinolate contents of 'Sinhongssam' grown under various light sources, periods, and light intensities (광원의 종류, 주기와 세기의 변화에 따른 '신홍쌈' 배추 내 글루코시놀레이트 함량)

  • Lee, Geon-Ryoung;Kim, Young Jin;Chun, Jin-Hyuk;Lee, Min-Ki;Ryu, Dong-Ki;Park, Suhyoung;Chung, Sun-Ok;Park, Sang Un;Lim, Yong-Pyo;Kim, Sun-Ju
    • Korean Journal of Agricultural Science
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    • v.41 no.2
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    • pp.125-133
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    • 2014
  • The variation of glucosinolates (GSLs) in Chinese cabbage ('Sinhongssam') (Brassica rapa L. spp. pekinensis) cultivated under lights to control plant growth conditions was evaluated at different development stages. Under experimental conditions in plant factory system, plant growth conditions including light, temperature, and nutrients were designed to enhance GSLs. The variation of glucosinolates (GSLs) in Chinese cabbage ('Sinhongssam') (Brassica rapa L. spp. pekinensis) cultivated under lights to control plant growth conditions was evaluated at different development stages. Under experimental conditions in plant factory system, plant growth conditions including light, temperature, and nutrients were designed to enhance GSLs. The contents of GSLs were quantified in Chinese cabbage according to different light sources (Red+White, RW; Red+Blue+White, RBW, Fluorescence lamp, FL) at development stages (28, 42, and 56 days after sowing, DAS) using HPLC. Nine GSLs including five aliphatic (progoitrin, sinigrin, glucoalyssin, gluconapin, and glucobrassicanapin) three indolyl (glucobrassicin, 4-methoxyglucobrassicin, and neoglucobrassicin), and one aromatic (gluconasturtiin) GSLs were identified based on peak retention time in previous results of our laboratory. GSL contents were higher in RBW (36.55) and lower in FL ($15.24{\mu}mol/g/\;DW$). Results revealed that GSL contents were higher under controlled photoperiods (20/4 h) ($58.35{\mu}mol/g\;DW$) and controlled light intensity ($160{\mu}mol/m^2/s$) ($34.02{\mu}mol/g\;DW$), respectively. Lower amount of progoitrin and comparatively higher amount of glucobrassicin and gluconasturtiin was noted in Chinese cabbage cultivated under FL light (2.38, 9.82, and 2.10) at 42 DAS, photoperiod 20/4 h (3.16, 2.52, and 1.30) at 28 DAS, and light intensity at $130{\mu}mol/m^2/s$ (2.28, 2.24, and $1.51{\mu}mol/g\;DW$) at 42 DAS. Therefore FL light, photoperiod (20/4 h), and light intensity ($130{\mu}mol/m^2/s$) were considered as most suitable for the enhancement of GSLs in Chinese cabbage.

Effects of photoperiod and light intensity on milk production and milk composition of dairy cows in automatic milking system

  • Lim, Dong-Hyun;Kim, Tae-Il;Park, Sung-Min;Ki, Kwang-Seok;Kim, Younghoon
    • Journal of Animal Science and Technology
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    • v.63 no.3
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    • pp.626-639
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    • 2021
  • The purpose of this study was to determine the effects of photoperiod and light intensity on milk production, milk composition, hormones levels and blood metabolites indices of Korean Holstein dairy cows in automatic milking system (AMS). A total of 24 Holstein dairy cows were selected and used to four subsequent treatments for the experimental periods of 60 days. The light programs consisted of (1) Control: the natural photoperiod with 14.2 h of the light period and 9.4 h of the dark period (below 10 Lux); (2) T1: 16 h of the long day photoperiod (LDPP) with 50 Lux of light; (3) T2: 16 h of LDPP with 100 Lux of light; and (4) T3: 16 h of LDPP with 200 Lux of light, respectively. Importantly, there was a significant difference in the thurl activity of dairy cows between the different light intensity programs (p < 0.05). Milk yield was higher in T1 and T2 (40.80 ± 1.71 and 39.90 ± 2.02 kg/d, respectively) than those of Control and T3 (32.18 ± 1.51 and 35.76 ± 2.80 kg/d, respectively) (p < 0.05), but DMI was lower in T1, T2, and T3 compared to Control (p < 0.05). Also, milk fat percentage, the contents of milk fat and total solids were higher in T2 than those in the others (p < 0.05). The average daily melatonin level in milk was high to T3 (28.20 ± 0.43 pg/mL), T2 (24.62 ± 0.32 pg/mL), T1 (19.78 ± 0.35 pg/mL), and Control (19.36 ± 0.45 pg/mL) in order (p < 0.05). Also, the cortisol levels in milk and blood were lower in treatment groups than in Control (p < 0.05). The results of this study showed that it will be effective to improve the milk yield and milk composition, and to reduce the stress of dairy cows when the light conditions regulate to extend the photoperiod to 16 h at a light emitting diode (LED) intensity of 100 Lux under the AMS in dairy farm.

A Regression of Miller Fisher Syndrome using Photic Feedback: Possibility of a New Complementary Therapy

  • Kamei, Tsutomu;Toriumi, Yoshitaka;Kumano, Hiroaki;Yasushi, Mitsuo
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.530-533
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    • 2002
  • We present a case of The Miller Fisher Syndrome (MFS), showing a remission during a recently developed noninvasive therapy. Two weeks after an appearance of cough and fever, a 35 years old Japanese male developed diplopia, ataxia and numbness of his fingers and toes. He was diagnosed as MFS, and a fixed dose of prednisolone acetate (60mg/day) was administered for 3 months, but little improvement was observed. In addition to this administration, we tried 20 minutes of Photic Feedback (PFB) treatment daily for 40 days. The PFB system detects brain waves from the subject's forehead, and extracts alpha waves by the band-pass filter with a center frequency set at 10.0Hz. It also simultaneously modulates the augmentation of a red light-emitting diode, corresponding with the amplitudes of the extracted alpha waves. In this treatment, this adjusted photic stimulation was given to the subject's closed eyes, resulting in the effective alpha enhancement by photic driving response. The numbness increased during each of PFB treatment, but the symptoms started to improve gradually after 10 days. Other symptoms disappeared after 40 days. CD20 levels increased with this treatment. This case suggests that the PFB treatment may speed the natural remission of MFS. This treatment may be worth considering in patients who suffer polyneuropathy.

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Luminescent Properties of Organic Light Emitting Diode Using $Alq_3$ Complex ($Alq_3$ 유도체를 사용한 유기전기발광소자의 발광 특성)

  • Yang, Ki-Sung;Kim, Doo-Seok;Kim, Byoung-Snag;Shin, Hoon-Kyu;Kim, Chung-Kyun;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.1703-1705
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    • 2004
  • New luminescent material, 6.11-dihydoxy-5.12-naphtacene-dione $Alq_3$ complex($Alq_2$-Ncd), 1.4-dihydoxy-5.8-naphtaquinone $Alq_3$ complex ($Al_2Nq_4$) was synthesized. The $Alq_2-$ Ncd and $Al_2Nq_4$ has big molecular weight and many ${\pi}$-electrons more than widely known $Alq_3$. And extended efforts have been made to obtain high-performance electro luminescent(EL) devices. We used hole transfer layer of powdered TPD to improve hole transfer and characteristics of interface in OLED. This study indicates not only the sterical effect but also some other effects that would be responsible for the change of the emission wavelength. improvement of luminance and etc.

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Flowable Oxide를 이용한 저온 Flexible OLED 박막봉지 제작

  • Yong, Sang-Hyeon;Kim, Dae-Gyeong;Kim, Hun-Bae;Jo, Seong-Min;Chae, Hui-Yeop
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.249-249
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    • 2012
  • 최근 주목받고 있는 Flexible Organic Light Emitting Diode (OLED) display에서는 Flexible 특성이 요구된다. 이는 현재 쓰이는 유리기판 대신 플라스틱기판으로 만들어야 가능하다. 하지만 플라스틱기판은 구성물질로 유기물을 사용하므로 수분과 산소의 투과에 매우 취약하다. 이는 장시간 사용 시 기판 위에 제작된 소자성능저하를 야기하는 등의 소자 신뢰도에 치명적 결함을 갖게 하는 원인이 된다. 따라서 기판 위의 소자를 보호할 수 있는 봉지기술 개발이 필요한데 가장 잘 알려진 플라스틱 기판에 적합한 Barrier기술로 유기물과 무기물을 교대로 적층하는 기술[1] 등이 있다. 본 연구에서는 PE-CVD 공정기술을 이용한 Flowable Oxide 박막과 ALD 공정기술을 이용한 Al2O3 무기물 박막을 적층하여 봉지박막을 구성하려 한다. Flowable Oxide는 저온공정이 가능하며 높은 증착속도와 뛰어난 Gap fill 특성을 가지고 있는데 이는 플라스틱기판의 엉성한 분자구조를 치밀하게 만들 것으로 예상되며 표면의 Pin-hole 또한 쉽게 채우는 특성이 있다. 실험은 Polyethylene Naphthalate (PEN) film 위에 PE-CVD 공정을 이용하여 Flowable Oxide를 증착하고, 그 후에 ALD 공정을 이용하여 Al2O3을 적층한 것을 하나의 샘플로 하였다. 샘플의 분석은 Ca test를 이용한 Water Vapor Transmission rate(WVTR)과 FT-IR, FE-SEM을 이용하여 분석하였다. FT-IR로 박막의 구성요소를 확인 하고 FE-SEM으로 박막의 Cross section image를 얻을 수 있었으며 또한 $4.85{\times}10^{-5}g/m^2$ day의 초기 WVTR 값을 얻을 수 있었다.

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Fabrication of Blue OLED with GDI Host and Dopant (GDI Host-Dopant를 이용한 청색 유기발광다이오드의 제작)

  • Jang, Ji-Geun;Shin, Se-Jin;Kang, Eui-Jung;Kim, Hee-Won;Seo, Dong-Gyoon;Lim, Yong-Gyu;Chang, Ho-Jung
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.773-776
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    • 2005
  • In the fabrication of high performance Blue organic light emitting diode, 2-TNATA[4,4',4"-tris(2-naphthylphenyl-phenylamino)-triphenylamine] as hole injection material and NPB[N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine] as hole transport material were deposited on the ITO (Indium Tin Oxide)/Glass substrate by vacuum evaporation. And then, Blue color emission layer was deposited using GDI602 as a host material and GDI691 as a dopant. Finally, small molecule OLED with the structure of ITO/2-TNATA/NPB/GDI602+GDI691/Alq3/LiF/Al was obtained by in-situ deposition of Alq3, LiF and Al as electron transport material, electron injection material and cathode, respectively. Blue OLED fabricated in our experiments showed the color coordinate of CIE(0.14, 0.16) and the maximum luminescence efficiency of 1.06 lm/W at 11 V with the peak emission wavelength of 464 nm.

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The Effect of Thermal Annealing Process on Fermi-level Pinning Phenomenon in Metal-Pentacene Junctions

  • Cho, Hang-Il;Park, Jin-Hong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.290.2-290.2
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    • 2016
  • Recently, organic thin-film transistors have been widely researched for organic light-emitting diode panels, memory devices, logic circuits for flexible display because of its virtue of mechanical flexibility, low fabrication cost, low process temperature, and large area production. In order to achieve high performance OTFTs, increase in accumulation carrier mobility is a critical factor. Post-fabrication thermal annealing process has been known as one of the methods to achieve this by improving the crystal quality of organic semiconductor materials In this paper, we researched the properties of pentacene films with X-Ray Diffraction (XRD) and Atomic Force Microscope (AFM) analyses as different annealing temperature in N2 ambient. Electrical characterization of the pentacene based thin film transistor was also conducted by transfer length method (TLM) with different annealing temperature in Al- and Ti-pentacene junctions to confirm the Fermi level pinning phenomenon. For Al- and Ti-pentacene junctions, is was found that as the surface quality of the pentacene films changed as annealing temperature increased, the hole-barrier height (h-BH) that were controlled by Fermi level pinning were effectively reduced.

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Design of SCR-Based ESD Protection Circuit for 3.3 V I/O and 20 V Power Clamp

  • Jung, Jin Woo;Koo, Yong Seo
    • ETRI Journal
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    • v.37 no.1
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    • pp.97-106
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    • 2015
  • In this paper, MOS-triggered silicon-controlled rectifier (SCR)-based electrostatic discharge (ESD) protection circuits for mobile application in 3.3 V I/O and SCR-based ESD protection circuits with floating N+/P+ diffusion regions for inverter and light-emitting diode driver applications in 20 V power clamps were designed. The breakdown voltage is induced by a grounded-gate NMOS (ggNMOS) in the MOS-triggered SCR-based ESD protection circuit for 3.3 V I/O. This lowers the breakdown voltage of the SCR by providing a trigger current to the P-well of the SCR. However, the operation resistance is increased compared to SCR, because additional diffusion regions increase the overall resistance of the protection circuit. To overcome this problem, the number of ggNMOS fingers was increased. The ESD protection circuit for the power clamp application at 20 V had a breakdown voltage of 23 V; the product of a high holding voltage by the N+/P+ floating diffusion region. The trigger voltage was improved by the partial insertion of a P-body to narrow the gap between the trigger and holding voltages. The ESD protection circuits for low- and high-voltage applications were designed using $0.18{\mu}m$ Bipolar-CMOS-DMOS technology, with $100{\mu}m$ width. Electrical characteristics and robustness are analyzed by a transmission line pulse measurement and an ESD pulse generator (ESS-6008).

LED PSU using an Integrated Transformer of New Shape (새로운 형상의 통합변압기적용 LED PSU)

  • Joo, Jong-Seong;Lee, Young-Soo;Heo, Ye-Chang;Kim, Eun-Soo;Hwang, In-Gab
    • The Transactions of the Korean Institute of Power Electronics
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    • v.22 no.1
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    • pp.27-35
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    • 2017
  • In this study, an integrated 2-in-1 transformer for a low-weight and low-cost light-emitting diode lighting power supply is proposed. In the transformer, a power factor correction (PFC) inductor and an LLC resonant transformer are placed and integrated on a single magnetic core. The amount of mutual interference, represented by the coupling coefficient, between magnetic fluxes generated from each magnetic source is minimized by using the new shape core of an integrated 2-in-1 transformer. The design consideration on critical conduction mode PFC converter and LLC resonant converter using the proposed 2-in-1 integrated transformer is described, and the overall performance of the 150 W LED PSU shown through the experiment.

Multi-channel Current Balancing Single Switch LED Driver for LED Backlight (LED Backlight를 위한 다채널 전류평형 단일스위치 LED 구동회로)

  • Hwang, Sang-Soo;Han, Sang-Kyoo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.21 no.4
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    • pp.320-327
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    • 2016
  • We propose a multi-channel current-balancing single switch light-emitting diode (LED) driver for a 3D TV. Conventional LED drivers require non-isolated DC/DC converters as many as the number of LED channels, whereas the proposed LED driver needs only one power switch and several balancing capacitors instead of expensive non-isolated DC/DC converters. Therefore, the proposed driver features a simple structure with low cost and high efficiency. In particular, because its power switch can be turned off under the zero-current switching condition, the proposed driver has desirable advantages, such as improved electromagnetic interference characteristics and high efficiency. Moreover, it only uses a small number of DC blocking capacitors with no additional active devices for the current balancing of multi-channel LEDs. Therefore, the proposed driver exhibits high reliability and cost effectiveness. To confirm the validity of the proposed driver, we perform a theoretical analysis and present design considerations and experimental results obtained from a prototype that is applicable to a 46" LED TV.