• 제목/요약/키워드: Observed discharge

검색결과 1,238건 처리시간 0.033초

면적비를 적용한 미계측유역에서의 설계홍수량 산정방안 (Estimation of Design Flood Discharge by Areal Ratio for Ungauged Basin)

  • 이지호;박재범;송양호;전환돈;이정호
    • 한국습지학회지
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    • 제19권3호
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    • pp.335-344
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    • 2017
  • 본 연구에서는 미계측유역의 설계홍수량을 산정하는 방안으로 유역의 면적비를 적용하는 방안을 제안하였다. 이를 위해 유역출구에서의 실측자료를 활용하여 유출매개변수를 결정하고 면적비를 적용하여 첨두홍수량을 산정하였다. 위 방법론을 검증하기 위해 소하천 유역의 관측유량 및 하천정비종합계획의 설계홍수량과의 비교를 통해 면적비 전이 방법론의 타당성을 검토하였다. 그 결과를 정리하면 다음과 같다. 면적비를 적용한 유출량과 관측유량자료를 비교한 결과 14~25% 정도의 차이를 보였다. 제안된 방법론의 타당성을 재확인하기 위해 하천정비종합계획에서 산정된 첨두유량과 소유역과의 면적비로 계산한 첨두유량을 비교하였다. 이를 위해 31개소의 소하천을 대상으로 설계홍수량을 비교한 결과, 20% 정도의 홍수량의 차이가 발생하였다. 따라서 면적비를 적용한 미계측지역에서의 첨두유량 산정방법론이 타당하다고 판단된다.

안정 Townsend 방전에 대한 혼입가스의 영향 (Influence of intermixed gas on stable townsend discharge)

  • 하성철
    • 전기의세계
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    • 제30권5호
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    • pp.306-312
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    • 1981
  • The Townsend discharge domain is generally observed with stable positive characteristics in N$_{2}$ gas discharge at low pressures differently in the others, which transfer immediately to glow dischage after self-sustaining discharge starts. In this paper, the presence of the stable Townsend discharge, applied voltage-discharge current characteristics and the effect of disgased electrode surface on stable townsend discharge are studied experimentaly in N$_{2}$ gas mixed with 0.05% of No in volume. As the result of this experiment, the stable Townssend discharge is observed only in pure nitrogen with the valve of pd.geq.8[torr.cm] (p=gas pressure, d=gap spacing), but not in gas mixtures. This is considered that No gas in gas mixtures disexcites effectively the metestble state of nitrogen.

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Spectroscopic Identification of Isomeric 2,3- and 2,6-Dimethylbenzyl Radicals in Corona Discharge

  • Yoon, Young Wook;Lee, Sang Kuk
    • Bulletin of the Korean Chemical Society
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    • 제34권3호
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    • pp.763-767
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    • 2013
  • We resolved the controversial assignments of the visible vibronic bands observed from corona discharge of 1,2,3-trimethylbenzene. The vibronic bands belonging to the jet-cooled 2,6-dimethylbenzyl radical were clearly identified from the spectrum observed from corona discharge of 2,6-dimethylbenzyl chloride. After subtracting the bands of the 2,6-isomer from the spectrum observed from corona discharge of 1,2,3-trimethylbenzene, the vibronic bands of the 2,3-isomer were also identified. By comparing data with the known vibrational data of 1,2,3-trimethylbenzene and the results of ab initio calculations, we determined the electronic energies of the $D_1{\rightarrow}D_0$ transitions and vibrational mode frequencies in the ground electronic states of the 2,3-and 2,6-dimethylbenzyl radicals.

평면형 대기압 유전장벽방전장치의 제작 및 동작특성분석 (Fabrication of Atmospheric Coplanar Dielectric Barrier Discharge and Analysis of its Driving Characteristics)

  • 이기융;김동현;이호준
    • 전기학회논문지
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    • 제63권1호
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    • pp.80-84
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    • 2014
  • The discharge characteristics of Surface Dielectric Barrier Discharge (SDBD) reactor are investigated to find optimal driving condition with adjusting various parameter. When the high voltage with sine wave form is applied to SDBD source, successive pulsed current waveforms are observed owing to multiple ignitions through the long discharge channel and wall charge accumulation on the dielectric surface. The discharge voltage, total charge between dielectrics, mean energy and power are calculated from measured current and voltage according to electrode gap and dielectric thickness. Discharge mode transition from filamentary to diffusive glow is observed for narrow gap and high applied voltage case. However, when the diffusive discharge is occurred with high applied voltage, the actual firing voltage is always lower than that with low driving voltage. The $Si_3N_4$, $MgF_2$, $Al_2O_3$ and $TiO_2$ are considered for dielectric protection and high secondary electron emission coefficient. SDBD with $MgF_2$ shows the lowest breakdown voltage. $MgF_2$ thin film is proposed as a protection layer for low voltage atmospheric dielectric barrier discharge devices.

Pulse-Sequence Analysis of Discharges in Air, Liquid and Solid Insulating Materials

  • Suwayno, Suwayno;Mizutani, Teruyoshi
    • Journal of Electrical Engineering and Technology
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    • 제1권4호
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    • pp.528-533
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    • 2006
  • Electrical discharges may occur in gas, liquid as well as solid insulating materials. This paper describes the investigation results on the discharges in air, silicone oil and low density polyethylene (LDPE) using needle plane electrode system under AC voltage of 50 Hz. The experimental results showed that for discharge in air (corona), discharge pulses were concentrated around the peak of applied voltage at negative half cycle. For silicone oil positive as well as negative discharges were observed which concentrated around the peak of applied voltage. The positive pulse number was smaller but the magnitude was higher than that of negative discharge. Discharges in void took place at wider range of phase of applied voltage. The unbalance in pulse number and magnitude similar to that of oil discharges were observed. For electrical treeing in LDPE, the discharges were spread before the zero cross of the applied voltage up to the peak at both positive and negative half cycles. The discharge pulse sequence analysis indicated that the PD occurrence in air, oil and void were strongly affected by the magnitude of applied voltage. However, for electrical treeing it was observed that the discharge occurrence was strongly affected by the time derivative of the applied voltage (dv/dt).

인공지능기법을 이용한 일유출량의 추계학적 비선형해석 (A Stochastic Nonlinear Analysis of Daily Runoff Discharge Using Artificial Intelligence Technique)

  • 안승섭;김성원
    • 한국농공학회지
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    • 제39권6호
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    • pp.54-66
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    • 1997
  • The objectives of this study is to introduce and apply neural network theory to real hydrologic systems for stochastic nonlinear predicting of daily runoff discharge in the river catchment. Back propagation algorithm of neural network model is applied for the estimation of daily stochastic runoff discharge using historical daily rainfall and observed runoff discharge. For the fitness and efficiency analysis of models, the statistical analysis is carried out between observed discharge and predicted discharge in the chosen runoff periods. As the result of statistical analysis, method 3 which has much processing elements of input layer is more prominent model than other models(method 1, method 2) in this study.Therefore, on the basis of this study, further research activities are needed for the development of neural network algorithm for the flood prediction including real-time forecasting and for the optimal operation system of dams and so forth.

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용천수 유출량 클러스터링 해석을 이용한 제주도 지하수 순환 해석 (Clustering Analysis with Spring Discharge Data and Evaluation of Groundwater System in Jeju Island)

  • 김태희;문덕철;박원배;박기화;고기원
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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    • pp.296-299
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    • 2005
  • Time series of spring discharge data in Jeju island can provide abundant information on the spatial groundwater system. In this study, the classification based on time series of spring discharge was performed with clustering analysis: discharge rate and EC. Peak discharges are mainly observed in august or september. However, double peaks and late peaks of discharge are also observed at a plenty of springs. Based on results of clustering analysis, it can be deduced that GH model is not appropriate for the conceptual model of Groundwater system in Jeju island. EC distributions in dry season are also support the conclusion.

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액체 He중 고분자 film의 연면 및 부분방전 연구 (Surface flashover discharge and partial discharge of polymer film in liquid helium)

  • 김상현;김현희;정순용;최효상
    • E2M - 전기 전자와 첨단 소재
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    • 제9권9호
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    • pp.942-948
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    • 1996
  • Electrical properties such as surface flashover discharge and discharge degradations of insulating materials for superconducting cable have been investigated. It is found that the surface voltage is proportional to $l^{0.7}$ (l: discharge length) in liquid helium (LHe). V-t characteristic in LHe was a n=5.5 that was less than liquid nitrogen (L $N_{2}$). After applied AC voltage, the surface condition of polymer films was observed non-eroded areas and eroded areas. The eroded area is depending on the applied voltage. In case of LHe, the crack was observed.d.

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방전가공기용 액체 절연재료의 아크 방전 특성 연구 (A study on the arc discharge characteristics of liquid insulating materials for electrical discharge machine)

  • 김상현;김해종;마대영;신태민
    • E2M - 전기 전자와 첨단 소재
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    • 제8권5호
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    • pp.564-571
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    • 1995
  • This paper deals with the arc discharge characteristics of kerosene oil as a basic study on electrical discharge machine. Using needle electrode the discharge voltage, discharge current, discharge energy and the shape of discharge crater are measured. In consequence, it becomes clear that the discharge crater(depth, height, diameter) is depending on the discharge energy. Rapid increase in depth, height and diameter of discharge crater was observed during initial discharge, where discharge energy is large. However, rather slow decrease of those values was found when discharge energy is low or N is more than 3. As the ratio of $I_p$$T_on$ increase, the shape of discharge crater gets near circle. The protuberances of the discharge crater were not formed by the melted needle electrode but by the that of work piece.

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Discharge Characteristics of Counter Electrode Discharge Cells of PDP

  • Kim, Young-Jin;Kim, Yong-Seog
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.477-479
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    • 2006
  • In this study, a stripe type counter electrode discharge cell for PDP was attempted to realize high luminance efficiency and low firing voltage for fine pitch discharge cells. The cells were prepared using electroplated Cu/Ni electrodes coated with glass dielectric layer. The discharge behaviors of such cells were observed. These results indicate that the counter electrode discharge cells have different discharge behavior compared with coplanar cells, which may affect the luminance efficiency of the panel.

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