• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.1184-1186
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• 2002

Recently, according to the industrial development relative to multimedia, demand of display system is radically increase, thus development for power supply of back-lighting is advanced lively. Fluorescent lamp operated at high frequency by the electronic ballast provide benefits like unnoticeable flicker effect and higher luminous efficiency. This paper presents analysis of Push-Pull type resonant inverter for CCFL drive for stable characteristic and life improvement of fluorescent lamp operated at high frequency. Also it has proposed design procedure of Current-Fed type resonant inverter. On the basis of equivalent circuit, component characteristic and suitable region of operation frequency from simulation using Matlab and Pspice is predicted. Suitability of applied equivalent model and validity of design process from the experimental results with CCFL inverter.

• Journal of Advanced Marine Engineering and Technology
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• 제26권3호
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• pp.382-388
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• 2002

Dissolved silica is one of fatal components at a boiler facility Therefore, a dissolved silica measurement system should be equipped for managing efficiently the boiler facility. Most of silica measurement systems are composed of a sensor module of single-beam type structure, and silica density is measured with a infrared spectrometry using the Lambert-beer method. However, such a system occurs measuring error of large range and inconsistency of a light source, because of measuring a standard sample and a measuring sample alternatively. This paper introduces a method that the sensor module has a split-beam type structure and a tungsten lamp. The proposed system can measure silica density quickly and precisely more than those composing of a single-beam type structure, because of measuring and comparing with two samples at a same time. And examination results are shown to compare efficiencies of the system and existing commercial products, and for an ammonia influence.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1623-1626
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• 2005

The thiogallate phosphors which are well known for a long time as phosphor materials for CRT or EL device were reported. Those have high luminescent properties at long-wavelength region. Among those phosphors, the samples with divalent europium doped CaGa2S4 were prepared by a simple process under the reduction atmosphere $(5%\;H_2/\;95%\;N_2)$ without toxic gas such as H2S or CS2. The prepared phosphor shows a higher luminescent efficiency (about 120%) than that of $YAG:Ce^{3+}$ phosphor. Consequently, this phosphor is possible to be applicable to white LED lamp because of the high luminescent efficiency.

• 한국산업융합학회 논문집
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• 제19권2호
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• pp.95-100
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• 2016

This study proposes the temperature compensation algorithm using thermopile detector for non-dispersive infrared Nitrogen gas sensor. From the output voltage of thermistor that is attached onto the infrared detector, the ambient temperature was extracted. The effects of temperatures on the properties of sensor module characteristics of narrow bandpass filter, optical cavity and infrared lamp, and air mixing gas have been introduced in order to implement the temperature compensation algorithm.

• Journal of Microbiology and Biotechnology
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• 제23권1호
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• pp.1-6
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• 2013

Tetanus is a specific infectious disease, which is often associated with catastrophic events such as earthquakes, traumas, and war wounds. The obligate anaerobe Clostridium tetani is the pathogen that causes tetanus. Once the infection of tetanus progresses to an advanced stage within the wounds of limbs, the rates of amputation and mortality increase manifold. Therefore, it is necessary to devise a rapid and sensitive point-of-care detection method for C. tetani so as to ensure an early diagnosis and clinical treatment of tetanus. In this study, we developed a detection method for C. tetani using loop-mediated isothermal amplification (LAMP) assay, wherein the C. tetani tetanus toxin gene was used as the target gene. The method was highly specific and sensitive, with a detection limit of 10 colony forming units (CFU)/ml, and allowed quantitative analysis. While detecting C. tetani in clinical samples, it was found that the LAMP results completely agreed with those of the traditional API 20A anaerobic bacteria identification test. As compared with the traditional API test and PCR assay, LAMP detection of C. tetani is simple and rapid, and the results can be identified through naked-eye observation. Therefore, it is an ideal and rapid point-of-care testing method for tetanus.

• 한국분말재료학회지
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• 제22권1호
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• pp.27-31
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• 2015

Flat panel display devices are mainly used as information display devices in the 21st century. The worldwide waste flat panel displays are expected at 2-3 million units but most of them are land-filled for want of a proper recycling technology More specifically, rare earth metals of La and Eu are used as fluorescent materials of Cold Cathode Flourscent Lamp(CCFL)s in the waste flat panel displays and they are critically vulnerable and irreplaceable strategic mineral resources. At present, most of the waste CCFLs are disposed of by land-filling and incineration and proper recovery of 80-plus tons per annum of the rare earth fluorescent materials will significantly contribute to steady supply of them. A dearth of Korean domestic research results on recovery and recycling of rare earth elements in the CCFLs prompts to initiate this status report on overseas research trends and noteworthy research results in related fields.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 F
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• pp.2783-2785
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• 1999

A fast switching gate driver suitable for high performance self resonant electronic ballasts is presented. The proposed gate driver has negligible switching loss and driving loss owing to pnpn structure and zero voltage switching( ZVS ); moreover, the gate driver has frequency control capability. Therefore, a self resonant inverter using proposed gate driver can operate as external exciting resonant inverters. The experiments confirm that the proposed gate driver perform the desired operations over full power control range for 40W fluorescent lamp electronic ballast.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 F
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• pp.2795-2797
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• 1999

Several power factor correction(PFC) circuits are presented to achieve high PF electronic ballast for both voltage-fed and current-fed electronic ballast. The proposed PFC circuits use valley-fill(VF) type DC-link stages modified from the conventional VF circuit to adopt the charge pumping method for PFC operations during the valley intervals. In voltage-fed ballast, charge pump capacitors are connected with the resonant capacitors. In current-fed type, the charge pump capacitors are connected with the additional secondary-side of the power transformer. The measured PF and THD are higher than 0.99 and 15% for all proposed PFC circuits. The lamp current CF is also acceptable in the proposed circuits. The proposed circuit is suitable for implementing cost-effective electronic ballast.

• 비파괴검사학회지
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• 제33권1호
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• pp.34-39
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• 2013

선행 연구에서 적외선열화상기법을 이용하여 원전 배관의 감육 결함을 측정하기 위하여, 4 inch 배관에 인공결함을 가공하여 이에 대한 결함 검출을 도출하였다. 본 논문에서는 선행연구에서 도출된 조건을 이용하여 원전 소구경 배관의 결함 검출 조건에 관한 연구를 수행하였다. 결함의 가공은 감육 길이, 원주방향 각도, 감육 깊이를 변화시켜서 결함 조건을 가공하였다. 사용된 장비는 IR camera와 1 kW용량의 halogen lamp 2개를 사용하였으며, halogen lamp와 대상 배관과의 거리를 1 m, 1.5 m, 2 m 순으로 변화시켜 실험을 수행하였다. 실험 결과의 분석을 위하여 온도분포데이터를 확보하고, 이를 분석하여 결함 길이를 측정하였다. 4 inch 배관의 인공결함은 2 m에서 측정 결과의 신뢰도가 높았으나, 소구경 배관은 1.5 m에서 결함이 명확하게 검출되었다.

• 대한화학회지
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• 제19권5호
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• pp.367-374
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• 1975

N-X-glycylphenylalanine methyl ester(X-trifluoroacetyl or acetyl)의 글리신잔기를 광 알킬화 반응에 의해 aspartic acid 의 유도체로 전환하였다. 이 반응은 diacetyl/di-t-butyl peroxide(DBP)를 광 개시제로, acetic anhydride를 알킬화제로 하여 350nm 파장의 램프를 사용하므로써 일어난다. DBP와 acetic anhydride에 의한 열반응의 경우에도 같은 알킬화 반응을 관찰하였다. 이 열알킬화 반응은 자유라디칼 반응을 거쳐 일어나기 때문에 이와 비교하여 광 알킬화 반응도 자유라디칼 메카니즘에 의해 일어난 것으로 추측된다.