• Title/Summary/Keyword: High Power LED

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Performance Analysis of Photovoltaic Power Generator by Usage Battery Charge (축전지 사용 유무에 따른 태양광발전기의 성능 분석)

  • Yun, Sung Wook;Choi, Man Kwon;Kim, Hyeon Tae;Yoon, Yong Cheol
    • Journal of Bio-Environment Control
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    • v.22 no.3
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    • pp.220-227
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    • 2013
  • This study examined the electric power quantity derived from solar radiation after installing a photovoltaic power generation system on the rooftop of building adjacent to a greenhouse with a view to reducing the operating expenses of the greenhouse by securing electric energy required to run it. Results of the study can be summed up as follows: The maximum, mean, and minimum solar radiation on the horizontal plane was $26.1MJ{\cdot}m^{-2}$, $14,0MJ{\cdot}m^{-2}$, and $0.6MJ{\cdot}m^{-2}$, respectively and individual the daily electric energy generated was about 6.1 kWh, 3.7 kWh, and 0.01 kWh. The cumulative total amounts of solar radiation and electric energy was about $4,378.2MJ{\cdot}m^{-2}$ and 1,163.2 kWh, respectively. Maximum, mean and minimum cumulative electric energy consumed through each load respectively was 4.5 kWh, 2.4 kWh, and 0.0 kWh and the cumulative electric energy were 739.2 kWh, which accounted for about 63.5% of generated power. In case of the mean amount of power consumption of the system used for this study, the small capacity of heater and the short operating hours meant there was enough power; while big capacity of heater led to a shortage, and if the array surface temperature increased relatively, the energy became proportionate to solar radiation and generated power does not increase. The correlation coefficient between the two factors was 0.851, which indicates a high correlation coefficient.

Transparent TIO/Ag NW/TIO Hybrid Electrode Grown on PET for Flexible Organic Solar Cell

  • Seo, Ki-Won;Lee, Ju-Hyun;Na, Seok-In;Kim, Han-ki
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.394.2-394.2
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    • 2014
  • We fabricated highly transparent and flexible Ti doped In2O3 (TIO)/Ag nanowire(NW)/TIO (TAT) multilayer electrodes by linear facing target sputtering (LFTS) and brush-painting for used as flexible for anode organic solar cells(FOSCs). The characteristics of TAT transparent anode as a function of number of brush-painting cycles was also investigated. At optimized conditions we achieved highly flexible TAT multilayer electrodes with a low sheet resistance of $9.01{\Omega}/square$ and a high diffusive transmittance more than 80% in visible region as well as superior mechanical stability. The effective embedment of the Ag NW network between top and bottom TIO films led to a metallic conductivity, high transparency. Based on FE-SEM HRTEM, and XRD analysis, we can find that the Ag NW network was effectively embedded between top and bottom TIO layers due to good flexibility of Ag NW, the TAT multilayer showed superior flexibility than single TIO layer. Successful operation of FOSCs with high power conversion efficiency of 3.01% indicates that TAT hybrid electrode is a promising alternative to conventional ITO electrode for high performance FOSCs.

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Miniaturized Ground-Detection Sensor using a Geomagnetic Sensor for an Air-burst Munition Fuze (공중폭발탄용 신관에 적용 가능한 초소형 지자기 지면감지 센서)

  • LEE, HanJin
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.5
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    • pp.97-105
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    • 2017
  • An air-burst munition is limited in space, so there is a limit on the size of the fuze and the amount of ammunition. In order to increase a firepower to a target with limited ammunition, it is necessary to concentrate the firepower on the ground instead of the omnidirectional explosion after flying to the target. This paper explores the design and verification of a ground-detection sensor that detects the direction of the ground and determines the flight-distance of an air-burst munition using a single axis geomagnetic sensor. Prior to the design of the ground detection sensor, a geomagnetic sensor model mounted on the spinning air-burst munition is analyzed and a ground-detection algorithm by simplifying this model is designed. A high speed rotating device to simulate a rotation environment is designed and a geomagnetic sensor and a remote-recording system are fabricated to obtain geomagnetic data. The ground detection algorithm is verified by post-processing the acquired geomagnetic data. Taking miniaturization and low-power into consideration, the ground detection sensor is implemented with analog devices and the processor. The output signal of the ground detection sensor rotating at an arbitrary rotation speed of 200 Hz is connected to the LED (Light Emitting Diode) in the high speed rotating device and the ground detection sensor is verified using a high-speed camera.

A study on the growth of AlN single crystals (AlN 단결정 성장에 관한 연구)

  • Kang, Seung-Min
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.23 no.6
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    • pp.279-282
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    • 2013
  • Recently, it has been interested much that AlN (Aluminum Nitride) crystals can be applied to UV LEDs and high power devices as like GaN and SiC crystals. The reports about commercial grade of AlN wafers in the world have been absent, however several results for growth of large size of AlN single crystals have been reported from abroad. In this report, the result of AlN single crystals of a diameter of about 8 mm grown are reported. Optical microscopic characterization was applied to observe the form of the crystals and the crystal quality was evaluated by FWHM measurement by DCXRD rocking curve analysis.

Accuracy Improvement of Screen Printed Ag Paste Patterns on Anodized Al for Electroless Ni Plating (무전해 Ni 도금을 위한 양극 산화막위에 스크린 인쇄된 Ag 페이스트 패턴의 정밀도 개선)

  • Lee, Youn-Seoung;Rha, Sa-Kyun
    • Korean Journal of Materials Research
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    • v.27 no.8
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    • pp.397-402
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    • 2017
  • We used an etching process to control the line-width of screen printed Ag paste patterns. Ag paste was printed on anodized Al substrate to produce a high power LED. In general, Ag paste spreads or diffuses on anodized Al substrate in the process of screen printing; therefore, the line-width of the printed Ag paste pattern increases in contrast with the ideal line-width of the pattern. Smudges of Ag paste on anodized Al substrate were removed by neutral etching process without surface damage of the anodized Al substrate. Accordingly, the line-width of the printed Ag paste pattern was controlled as close as possible to the ideal line-width. When the etched Ag paste pattern was used as a seed layer for electroless Ni plating, the line width of the plated Ni film was similar to the line-width of the etched Ag paste pattern. Finally, in pattern formation by Ag paste screen printing, we found that the accuracy of the line-width of the pattern can be effectively improved by using an etching process before electroless Ni plating.

Antioxidant and Protective Effects of Palmul-tang on Ultraviolet B (UVB)-induced Damage in Human Keratinocytes (팔물탕의 항산화 효과와 자외선으로 유도된 각질형성세포 손상에 대한 보호효과)

  • Kim, Tae-Yeon;Bak, Jong-Phil
    • Journal of Society of Preventive Korean Medicine
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    • v.19 no.3
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    • pp.141-154
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    • 2015
  • Objective : In this paper, we investigated the anti-oxidative capacities and protective effects of water extract of palmul-tang (PMT) against Ultraviolet B(UVB)-induced oxidative damage in human keratinocytes(HaCaT). Method : To evaluate the anti-oxidative activities of PMT, we measured scavenging activities on 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical, hydroxyl radical, hydrogen peroxide, superoxide anion, lipid peroxidation and reducing power of PMT. To give an oxidative stress to HaCaT cells, UVB was irradiated with $40mJ/cm^2$ to HaCaT cells. To detect the protective effects of PMT against UVB, we measured cell viability, apoptotic bodies and reactive oxygen species(ROS) generation. Results : PMT showed the anti-oxidative activities by scavenging DPPH radical, hydroxyl radical, hydrogen peroxide, superoxide anion, lipid peroxidation. Also PMT showed high reducing values. The UVB-induced oxidative conditions led to the cell apoptosis. However, treatment with PMT reduced oxidative stress conditions, including inhibition of cell apoptosis and expression of ROS. Conclusion : PMT had anti-oxidative activities and exhibited protective effects against UVB on HaCaT cells. PMT would be useful for the development of cosmetics treating UVB-induced skin aging.

A Study on Normative Expectation of Emotional Process in Children′s Tectbooks of the Chosen Dynasty(II) (조선시대 아동교육용 문헌에 나타난 정서과정에 대한 구범적 기대(II))

  • Shin Yangjai
    • Journal of the Korean Home Economics Association
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    • v.42 no.11
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    • pp.17-30
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    • 2004
  • The purpose of this study was to explore the normative expectations of positive emotions such as happiness and pride in Korean culture by analyzing the children's textbooks in the Chosen Dynasty period. The method of this study was document analysis and the materials for analysis were 'Dongmongsensp', 'Gyukmongyogyul', 'Myungimbogam', and 'Sohak', that were the textbooks for children's education and invoked the ethics of individual life based on Confucianism. The analysis was focused on the antecedent events, emotional consequences, and emotional regulation in the emotional process of happiness and pride. According to the analysis, happiness was caused by the accomplishment of cultural tasks such as supporting parents, observing laws, being moderate, improving oneself with reading good books, and modeling good deeds, as well as parents' love, which had desirable consequences. Hence, the emotional regulation was to enhance happiness, but far as immoderate experience of happiness, the regulatory rule was expected to suppress it. Also, the antecedents of pride were those demonstrating to have power or occupying a high social position, and the consequences of pride led to self-destruction, and pride was therefore not allowed to be expressed. Consequently, happiness was enhanced because it motivated individuals to accomplish cultural tasks of interdependence, whereas pride was inhibited because it tended to disengage self from social connectedness.

Estimation of GHG emission and potential reduction on the campus by LEAP Model (LEAP 모델을 이용한 대학의 온실가스 배출량 및 감축잠재량 분석)

  • Woo, Jeong-Ho;Choi, Kyoung-Sik
    • Journal of Environmental Impact Assessment
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    • v.21 no.3
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    • pp.409-415
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    • 2012
  • Post-kyoto regime has been discussing with the GHG reduction commitment. GHG energy target management system also has been applied for the domestic measures in the country. Universities are major emission sources for GHG. It is very important for campus to built the GHG inventory system and estimate the potential GHG emission reduction. In general, GHG inventory on the campus was taken by the IPCC guidance with the classification of scope 1, 2, and 3. Electricity was the highest portion of GHG emission on the campus as 5,053.90 $tonsCO_2eq/yr$ in 2009. Manufacturing sector was the second high emission and meant GHG in laboratory. Potential GHG reduction was planned by several assumptions such as installation of occupancy sensor, exchanging LED lamp and photovoltaic power generation. These reduction scenarios was simulated by LEAP model. In 2020, outlook of GHG emission was estimated by 17,435.98 tons of $CO_2$ without any plans of reduction. If the reduction scenarios was applied in 2020, GHG emission would be 16,507.60 tons of $CO_2$ as 5.3% potential reduction.

WLED Communication System Using SC-FDMA Techniques (SC-FDMA기술을 적용한 WLED 통신시스템)

  • Li, Xun;Park, Noe-Yoon;Kim, Young-Ju
    • The Journal of the Korea Contents Association
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    • v.10 no.10
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    • pp.94-101
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    • 2010
  • In this paper, a WLED communication system with SC-FDMA technique is proposed. OFDM is a promising technique to realize high-speed WLED communication system. However, because of the PAPR, the system performance can be significantly compromised by non-linear distortions in the transmission chain. Furthermore, the overload current due to peak signal power lead the WLED equipment over bright which is harmful to equipment life and human‘s eye. The novel WLED communication system proposed in this paper solved these problems by using SC-FDMA technique which has an inherent low PAPR property. The severity of PAPR performances expressed by CCDF curve and the BER performances under different modulation schemes are analyzed in this paper.

Development of Automated Surface Inspection System using the Computer V (컴퓨터 비젼을 이용한 표면결함검사장치 개발)

  • Lee, Jong-Hak;Jung, Jin-Yang
    • Proceedings of the KIEE Conference
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    • 1999.07b
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    • pp.668-670
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    • 1999
  • We have developed a automatic surface inspection system for cold Rolled strips in steel making process for several years. We have experienced the various kinds of surface inspection systems, including linear CCD camera type and the laser type inspection system which was installed in cold rolled strips production lines. But, we did not satisfied with these inspection systems owing to insufficient detection and classification rate, real time processing performance and limited line speed of real production lines. In order to increase detection and computing power, we have used the Dark Field illumination with Infra_Red LED, Bright Field illumination with Xenon Lamp, Parallel Computing Processor with Area typed CCD camera and full software based image processing technique for the ease up_grading and maintenance. In this paper, we introduced the automatic inspection system and real time image processing technique using the Object Detection, Defect Detection, Classification algorithms. As a result of experiment, under the situation of the high speed processed line(max 1000 meter per minute) defect detection is above 90% for all occurred defects in real line, defect name classification rate is about 80% for most frequently occurred 8 defect, and defect grade classification rate is 84% for name classified defect.

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