• Title/Summary/Keyword: UM

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Wall charge & Wall Voltage Characteristics on Sustain Driving Voltage in AC PDP

  • 김태영
    • Proceedings of the Korean Vacuum Society Conference
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    • 1999.07a
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    • pp.237-237
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    • 1999
  • 전극폭 300um, 전극간격 100um, 격벽높이 130um로 자체 제작한 테스트 패널에서 방전개시전압과 최소 방전유지전압 사이에서 방전유지전압 변화에 따른 벽전하, 벽전압을 측정하였다. 이 실험에서는 Ne가스와 Ne-Xe 혼합가스를 이용하였다. 이 결과로부터 방전유지전압 변화에 따른 벽전하, 벽전압을 통하여 최적의 방전유지전압 조건을 결정할 수 있으며, 이는 AC-PDP의 효율 향상에 기여할 것으로 판단되어 진다.

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Permutation P-values for Inter-rater Agreement Measures

  • Um, Yonghwan
    • Journal of the Korea Society of Computer and Information
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    • v.20 no.12
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    • pp.169-174
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    • 2015
  • Permutation p-values are provided for the agreement measures for multivariate interval data among many raters. Three agreement measures, Berry and Mielke's measure, Janson and Olsson's measure, and Um's measure are described and compared. Exact and resampling permutation methods are utilized to compute p-values and empirical quantile limits for three measures. Comparisons of p-values demonstrate that resampling permutation methods provide close approximations to exact p-values, and Berry and Mielke's measure and Um's measure show similar performance in terms of measuring agreement.

Influence of Frequency and Duty Ratio on Electro-Optical Characteristics in AC-PDP

  • 김태영
    • Proceedings of the Korean Vacuum Society Conference
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    • 2000.02a
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    • pp.203-203
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    • 2000
  • VDS(Versatile Driving Simulator) 시스템을 이용하여 방전유지전압펄스의 휴지기 변화에 따른 공간전하의 거동과 벽전하, 벽전압 및 효율 특성을 연구하였다. 이때 휴지기 변화에 따른 실험을 위하여 방전유지전압의 진동수 및 duty ratio를 변화시켰고, 사용된 테스트 패널은 전극폭 260um, 전극간격 100um, 격벽높이 120um, 기압은 400Torr로 Ne-Xe(4%) 기체를 사용하였다. 이 결과로부터 방전유지전압펄스의 휴지기 변화에 따른 벽전하, 벽전압 및 효율 측정을 통하여 최적의 방전유지전압펄스의 조건을 결정할 수 있으며, 이는 AC PDP의 효율 향상에 기여할 것으로 판단되어 진다.

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Fabrication of zirconiumfluoride Glasses used for 1.54um Fiber Amplifier (1.54um 광섬유 광증폭기 Er-doped Zirconiumfluoride 유리제조)

  • 조운조
    • Proceedings of the Optical Society of Korea Conference
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    • 1989.02a
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    • pp.140-142
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    • 1989
  • 1.54um 파장에서 최대 형광을 나타내는 ZrF4-BaF2-LaF3-AlF3-NaF : ErF3 유리를 built-in-casting 법에 의해 제조하였다. Er+3 이온을 0.2몰부터 4몰까지 첨가하였으며, Er+3 이온의 4I13/2 준위의 lifetime 은 Er+3 이온 0.2몰부터 2몰까지 28msec로 최대값을 갖으며 4몰일때는 급격히 감소하였다.

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Herschel/PACS spectroscopy of the supernova remnant G21.5-0.9

  • Cha, Heechan;An, Hongjun
    • The Bulletin of The Korean Astronomical Society
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    • v.45 no.1
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    • pp.53.1-53.1
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    • 2020
  • We present Herschel Space Observatory far-IR observations of the supernova remnant(SNR) G21.5-0.9. We search PACS-IFU data for 63um [O I], 88um [O III], 157um [C II] emission lines and detect the [O II] and the [C II]. We then produce emission line maps to check the spatial distribution of the elements. We compare the maps to Radio, IR-photometrics, and X-ray images in order to understand interaction of the ejecta with the Pulsar Wind Nebula(PWN) and physical environment in the SNR.

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High Efficiency 5A Synchronous DC-DC Buck Converter (고효율 5A용 동기식 DC-DC Buck 컨버터)

  • Hwang, In Hwan;Lee, In Soo;Kim, Kwang Tae
    • Journal of Korea Multimedia Society
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    • v.19 no.2
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    • pp.352-359
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    • 2016
  • This paper presents high efficiency 5A synchronous DC-DC buck converter. The proposed DC-DC buck converter works from 4.5V to 18V input voltage range, and provides up to 5A of continuous output current and output voltage adjustable down to 0.8V. This chip is packaged MCP(multi-chip package) with control chip, top side P-CH switch, and bottom side N-CH switch. This chip is designed in a 25V high voltage CMOS 0.35um technology. It has a maximum power efficiency of up to 94% and internal 3msec soft start and fixed 500KHz PWM(Pulse Width Modulation) operations. It also includes cycle by cycle current limit function, short and thermal shutdown protection circuit at 150℃. This chip size is 2190um*1130um includes scribe lane 10um.

Probe Pitch에 따른 Si 식각 특성 연구

  • Han, Seok-Man;Sin, Jae-Cheol;Go, Hang-Ju;Han, Myeong-Su
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.316-316
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    • 2012
  • 본 연구에서는 Si wafer에 마스크 공정 및 Slit-etching 공정을 적용하여 25 um 피치의 probe unit을 개발하기 위해 Deep Si Etching 장비를 이용하여 식각공정 조건에 따른 특성을 평가하였다. 25 um pitch는 etch 폭의 크기에 따라 3종류로 설계하였으며, 식각공정은 2수준, 4인자 실험계획법에 의해 8회 실험을 수행하였다. 실험계획법에 의해 미니탭을 활용하여 최적조건을 구한 결과 12.5 um etch 폭에서는 가스유량은 200 sccm, 에칭시간 7 sec, 코일 파워 1500W, 에칭 압력은 43.7 mtorr의 조건이 etch 형태 및 profile angle이 목표치에 근접한 결과를 얻었다. 또한 probe pitch를 30~60 um까지 증가시켰을 경우 Etch depth는 증가하였으며, 식각율 또한 증가한 현상을 보였다. 재현성 실험을 위해 위의 최적조건을 이용하여 2회 반복하여 실험한 경우 모든 시편이 목표치에 도달하였다. 이는 미세피치화 되는 프로브 유닛의 기초데이터로 활용될 수 있다.

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Study of relationship between three Um and three Yang(三陰三陽) of Unki theory(運氣學) and the Geon divination sign(乾卦) of Iching(周易) (運氣學의 三陰三陽과 周易 乾卦 六爻의 相關關係에 대한 硏究)

  • Park, Chan-Guk
    • Journal of Korean Medical classics
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    • v.13 no.2 s.17
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    • pp.13-13
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    • 2000
  • Both of the three Um and three Yang and the six hyo(六爻) of Iching are based on Um and Yang theory and five phases theory. This paper is about mutual relation of them. First, every change in the universe is induced by Un and Ki. Un is the nature that things have their own. Ki is surroundings that things change in. Second, Un and Ki are not separate things. That is they are generated by each other. Third, both of them are the signs of change which means they are similar. The first Hyo (初爻) and Kwolum-pungmok(厥陰風木), the seond Hyo(二爻) and Soum-gunhwa(少陰君火), the third Hyo(三爻) and Teum-supto(太陰濕土), the forth Hyo(四爻) and Soyang-sanghwa(少陽相火), the fifth Hyo(五爻) and Yangmyung-zogum(陽明燥金), and the sixth Hyo(六爻) and Teyang-hansu(太陽寒水) have similar principles. It is important to make clear up their meanings and mutual relation.

Tolerance of the Mutants of Pyricularia oryzae against Mercuric Chloride (자외선조사에 의해 유도된 도열병균의 승홍에 대한 내성에 관하여)

  • 김경호
    • Journal of Plant Biology
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    • v.22 no.3
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    • pp.85-91
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    • 1979
  • Tolerance against mercuric chloride in mutants of Pyricularia oryzae Cavara induced by ultraviolet(UV) irradiation has been investigated. The tolerant isolates obtained using ultraviolet(UV) irradiation were maintained a high level of tolerance even after 15 times transfer to the chemical free media. Each isolate of mutants UM-1, UM-2, and UM-3 on the successive monoconidial culture has genetically homogeneous for tolerance. The tolerant isolates sporulated less and showed a higher percentage of germination of conidia on media without the chemical than the parental isolate. The xotins released from the parental and the tolerant isolates have been identified as piricularin and $\alpha$-picolinic acid by paper-chromatography. The tolerant isolates produced more piricularin and its virulence on seedlings of rice varieties were higher than the parental isolates. Both piricularin production and virulance on rice were highest in the UM-2 isolate.

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fabrication of the Microfluidic LOC System with Photodiode (광 다이오드를 가진 Microfluidic LOC 시스템 제작)

  • 김현기;신경식;김용국;이상렬;김태송;양은경;주병권
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.12
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    • pp.1097-1102
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    • 2003
  • In this paper, we used only PR as etching mask, while it used usually Cr/AU as etching mask, and in order to fabricate a photosensor has the increased sensitivity, we investigated on the sensitivity of general type and p-i-n type diode. we designed microchannel size width max 10um, min 5um depth max 10um, reservoir size max 100um, min 2mm. Fabrication of microfluidic devices in glass substrate by glass wet etching methods and glass to glass fusion bonding. The p-i-n diode has higher sensitivity than photodiode, Considering these results, we fabricated p-i-n diodes on the high resistive(4㏀$.$cm) wafer into rectangle and finger pattern and compared internal resistance of each pattern. The internal resistance of pin diode can be decreased by the application of finger pattern has parallel resistance structure from 571Ω to 393Ω.