• 제목/요약/키워드: Discharge phenomena

검색결과 284건 처리시간 0.024초

초청정 클린룸의 공기이온화에 대한 실험적 연구 (Experimental Study on Air Ionization Phenomena in the Super Clean Room)

  • 오명도;배태식;김선창
    • 설비공학논문집
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    • 제4권2호
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    • pp.72-81
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    • 1992
  • Experimental study on air ionization phenomena has been conducted to analyze the propagation behavior and dischargeability of polarity air ions under the super clean room environments with the operation of prototype of Air Ionization System. Varying humidity and air velocity, the distribution of air ion density and the discharge time are measured and analyzed.

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제주도 하천의 수위-유량 변동특성연구

  • 문덕철;하규철;고기원;박기화
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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    • pp.422-425
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    • 2004
  • To understand runoff Phenomena in Jeju island, some streams are monitored automatically about stream stage, and water quality in Jeju Provincial Water Resources Management Office. Rating curves for stream discharge are reviewed. Stream stages respond very quick to some rainfall events, and parameters influencing runoff phenomena such as landuse, soil condition, preconditoned rainfall, and vegetables will be studied. A few thousand to ten thousand ml/day are estimated from 6 permanent streams in Jeju island.

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CAPD기법을 이용한 부분방전 현상 해석에 관한 연구 (Analysis of Partial Discharge Phenomena by means of CAPD)

  • 김성홍
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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    • pp.939-944
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    • 2002
  • PD phenomena can be regarded as a deterministic dynamical process where PD should be occurred if the local electric field be reached to be sufficiently high. And thus, its mathematical model can be described by either difference equations or differential equations using several state variables obtained from the time sequential measured data of PD signals. These variables can provide rich and complex behavior of detectable time series, for which Chaos theory can be employed. In this respect, a new PD pattern recognition method is proposed and named as 'Chaotic Analysis of Partial Discharges (CAPD)' for this work. For this purpose, six types of specimen are designed and made as the models of the possible defects that may cause sudden failures of the underground power transmission cables under service, and partial discharge signals, generated from those samples, are detected and then analyzed by means of CAPD. Throughout the work, qualitative and quantitative properties related to the PD signals from different defects are analyzed by use of attractor in phase space, information dimensions ($D_0$ and D2), Lyapunov exponents and K-S entropy as well. Based on these results, it could be pointed out that the nature of defect seems to be identified more distinctively when the CAPD is combined with traditional statistical method such as PRPDA. Furthermore, the relationship between PD magnitude and the occurrence timing is investigated with a view to simulating PD phenomena.

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대전인체의 정전기 방전에 대한 동적해석 - 준정적해석과의 비교 (Dynamic analysis of charged human body electrostatic discharge - comparison with quasi-static discharge)

  • 이종호;김두현;김상철;김상렬
    • 한국산업안전학회:학술대회논문집
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    • 한국안전학회 1998년도 춘계 학술논문발표회 논문집
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    • pp.257-262
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    • 1998
  • In order to understand the characteristics of electrostatic discharge (ESD) by a charged human body, a dynamic analysis method based on RCL circuit and a quasi-static analysis method based on two-body model are introduced. In this paper, these methods calculate waveforms, discharge energy and potential difference to analyze the ESD phenomena from given initial conditions and geometry. Results are compared and discussed.

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청각 계통에서의 음성신호처리 (Speech signal processing in the auditory system)

  • 이재혁;심재성;백승화;박상희
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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    • pp.680-683
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    • 1987
  • The speech signal processing in the auditory system can be analysized based on two representations : Average discharge rate and Temporal discharge pattern. But the average discharge rate representation is restricted by the narrow dynamic range because of the rate saturation and the two tone suppression phenomena, and the temporal discharge pattern representation needs a sophisticate frequency analysis and synchrony measure. In this paper, a simple representation is proposed : using a model considering the interaction of Cochlear fluid-BM movement and a haircell model, the feature of speech signals (formant frequency and pitch of vowels) is easily estimated in the Average Synchronized Rate.

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Reduction of Temporal Image Sticking in AC Plasma Display Panels through the Use of High He Contents

  • Park, Choon-Sang;Kim, Sun-Ho;Kim, Jae-Hyun;Tae, Heung-Sik
    • Journal of Information Display
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    • 제10권4호
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    • pp.195-201
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    • 2009
  • The temporal dark- and bright-image sticking phenomena were examined relative to the He contents under 11% Xe content in the 50-in HD and FHD AC-PDPs with a ternary gas mixture (Xe-He-Ne). To compare the temporal dark- and bright-image sticking phenomena under various He contents, the differences in the disappearing time, display luminance, perceived luminance, infrared emission, color coordinate, color temperature, and discharge current before and after discharge were measured under 0, 35, 50, and 70% He contents. It was found that temporal dark- and bright-image sticking were reduced in proportion to the increase in He %. Thus, a high He content contributes to the reduction of temporal dark- and bright-image sticking.

Corona방전에 의한 유전체의 열화현상 (The Deterioration Phenomena for Dielectrics Causing Corona Discharge)

  • 성영권;백영학;차균현
    • 전기의세계
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    • 제19권6호
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    • pp.18-25
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    • 1970
  • The object of this project is to manifest the mechanism of deterioration phenomena for dielectrics causing corona discharge and applies it for determine the standard corona detection technique. As the results, we observed that corona discharges may occur more strongly around cylindrical shape electrode in air than hemisphere shape electrode in vacuum, so that it depends on effects such as shape of the electrode, moisture, surface coditions, etc. According to observed the deterioration of dielectrics takes place in following stages. At first the attacked surface by an electron avalanche is uniformly eroded; then pits are formed; after that sharp channels are formed which lead to break-down as a treeing. The test are accelerated with higher frequencies by the cylindrical bar shape electrode in the pulse stright detection method more sensitive than Lissajous patterns. Lissajous patterns detection method is simple but usually insensitive and has disadvantage that the magnitude of the individual discharge is not measured.

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Electrostatic discharge in TFT manufacturing process

  • Long, Chunping;Lee, Xinxin;Wang, Wei
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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    • pp.908-910
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    • 2007
  • Thin Film Transistor (TFT) manufacturing process is complicated. Electrostatic discharge (ESD) occurs during every process step. This paper describes ESD phenomena in terms of TFT design and processing flow. The abnormal contact between equipment and glass is found out to be the key reason causing ESD.

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약한 충격파의 반사와 방출에 관한 개구단 보정 (Open End Correction for the Reflection and Discharge of Weak Shock Wave)

  • 이동희;김희동;뢰호구후명
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집E
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    • pp.349-354
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    • 2001
  • The present study addresses the open end correction associated with the reflection and discharge phenomena of a weak shock wave from an open end of a duct. The open end correction of the weak shock wave is investigated experimentally and by numerical computation. An experiment is made using a simple shock tube with an open end, and computation is performed to simulate the experimental flow field using the unsteady, axisymmetric, compressible, flow governing equations. The results obtained show that an open end correction should be involved for shock wave discharge and reflection problems generated from the exit of the duct with an open end baffle plate. With a baffle plate less than three times the duct diameter, it is found that the open end correction is a function of both the diameter of the baffle plate and normal shock wave magnitude. However, for a baffle plate larger than three times the duct diameter, it is independent of the baffle plate diameter. The present computations predict the results of shock tube experiment with good accuracy. A new empirical equation for prediction of the open end correction is found for the weak shock reflection and discharge phenomena occurring at the open end of the duct with and without a baffle plate.

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CDM ESD 현상의 혼합모드 과도해석 (Mixed-Mode Transient Analysis of CDM ESD Phenomena)

  • 최진영;송광섭
    • 대한전자공학회논문지SD
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    • 제38권3호
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    • pp.155-165
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    • 2001
  • 2차원 소자 시뮬레이터를 사용하는 혼합모드 과도해석 방법을 제시하여, NMOS 트랜지스터를 ESD 보호용 소자로 사용하는 CMOS 칩에서의 충전소자모델(CDM) ESD 현상에 대한 분석을 시도하였다. 과도해석 결과의 분석을 통해 CDM 방전 경우 소자 파괴에 이르는 미케니즘에 대해 상세히 설명하였고 충전전기의 극성에 따른 방전 특성의 차이점도 비교 분석하였다. CDM 방전에서 가장 문제가 되는 입력버퍼의 게이트 산화막 파괴문제와 관련하여 배선저항 값의 변화에 의한 영향을 검토하였고, 입력버퍼회로 보호용 NMOS 트랜지스터의 추가에 의한 방전 특성의 변화에 대해 조사하였다.

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