• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1737-1739
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• 1998

The paper presents experimental results of Partial Discharge(PD) in Gas Insulated Switchgear(GIS), obtained using a computer-aided PD measurement system. Different discharge sources are simulated and identified. These included internal, interface, surface and protrusion. For internal discharge, it showed symmetrical discharge type between positive and negative cycle. Interface discharge showed smaller number and higher peak than internal discharge but symmetrical discharge as well. For surface discharge, it showed small number and high peak in positive half cycle but large number and low peak in negative half cycle. For protrusion discharge, small number and high peak of discharge were shown only in negative half cycle.

• Journal of Environmental Science International
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• v.16 no.4
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• pp.487-493
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• 2007

In this study is analysis which dams breach shapes are effect on peak discharge of dam-failure. The dam breach shapes and failure time are important peak discharge when dam failure. When dam failure times are 1hr, 2hr and 3hr condition for the ECRD and 0.1hr and 0.2hr for the CG and CFRD that breach shapes changed base length $B_b=1Hd,\;B_b=2Hd\;and\;B_b=3Hd$. As the results from DAMBRK(Dam Break model) peak discharge are increase base widths lengthen. As failure time is longer then peak discharge is decrease. So peak discharge is increase more short of dam failure time. Also peak discharge is increase become larger dam breach shapes.

• Water for future
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• v.29 no.3
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• pp.153-161
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• 1996

This study is runoff analysis of the recently urbanized San Bon basin. The relationships between peak discharge and total discharge were examined by applying the ILLUDAS runoff analysis model to the measured data. In urbanized streams, it is found that channel adjustment had the most significant effect on the increase of peak discharge. Significant increases in the peak discharge occurred as rainfall duration or return period increases 10% and 7~16% increases in peak discharge were observed when the roughness coefficient were 0.04 and 0.015, respectively. When the natural river channel with n=0.04 was converted into a sewerage system of n=0.015 the peak discharge was greatly increased by 51~158%, Generally, flood peak discharge was increased during heavy rain, but in the case of urbanized basin, river stage was reduced owing to an increase of flow velocity by the adjustment of drainage system.

• YAKHAK HOEJI
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• v.39 no.5
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• pp.480-486
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• 1995

The change in discharge current of a glow discharge has been shown the potential sensitive detector for gas chromatography. To investigate the effect of carrier gas on the electrical characteristics of the discharge and the peak response, the discharge pressure, gas flow rate, and discharge gap have been studied. The discharge gas included the Ar, He, and N$_{2}$. The gas flow rate has been found one of the important parameters to affect both the electrical characteristics and the peak response.

• Water for future
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• v.19 no.2
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• pp.157-166
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• 1986

The objective of this study was to determine the best representative synthetic unit hydrograph that is applicable to ungaged small watershed. A typical unit hydrograph was established with the actual data from a small watershed. Four currently well-known methods for analyzing ungaged small watershed, including Snyder's, Clark's S.C.S. and Nash methods, were evaluated with the data from the same small watershed. The following observations were noted from the analysis of four methods. The Snyder's method yielded the similar peak discharge value as the typical unit hydrograph. With co-ordinates of three discharge values, i.e. 25%, 50% and 75% of peak discharge, were not adequate for deriving a typical unit hydrograph in ungaged small watershed. With Clark's method there shall be some way of obtaining the exact base length of time area diagram and isochrone of each reach of the stream. With Nash method peak discharge and base flow time are affected by the storage constant and gamma function argument; therefore, for deriving a more reliable and workable unit hydrograph one needs to select for the better estimation of storage constant and gamma function argument. In S.C.S. method peak discharge is directly related to the watershed area and inversely related to the time of peak diacharge. Therefore area with faster peak discharge yielded the higer peak discharge value. Although the peak discharge value obtained frome the S.C.S. method higher than the value obtained from the unit hydrograph developed from the actual data, this method contains a number of advantageous factors. The peak discharge value and the time of peak discharge can be claculated easity from the morphological characteristics of the watershed, and in S.C.S method co-ordinates of the unit hydrograph can be calculated easily from that of the dimensionless unit hydrograph. When the four currently used methods were evaluated with a typical unit hydrograph obtained from the actual data, the S.C.S method was show to be the best method in deriving a synthetic unit hydrograph for ungaged small watershed.

• Journal of Korean Society of Water and Wastewater
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• v.14 no.3
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• pp.251-259
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• 2000

In this study, the urban runoff models, ILLUDAS model and SWMM, are analyzed the probable peak discharge and discharge using rainfall distribution by Huff's method at Bum-uh chun area in Taegu city. The probability rainfall and intensity is analyzed by Pearson-III type. The rainfall duration, 90 minutes, is determined by the critical duration computed the maximun peak discharge for some rainfall durations. The peak discharge according to Huff's rainfall distribution types compute in order of type 3, type 4, type2, and type 1, so Huff's 3 type is selected as an adequate rainfall distribution in Bum-uh chun basin. ILLUDAS model and SWMM are shown as good models in Bum-uh chun, but SWMM is computed higher peak discharge than ILLUDAS model, so SWMM is shown as the adequate urban runoff model for the design of interior drainage in urban basin.

• Journal of Korea Water Resources Association
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• v.43 no.7
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• pp.635-643
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• 2010

A representative unit hydrograph responding to a small basin is used to calculate the flood discharge in the basin. The peak discharge and the time to peak of the unit hydrograph are dealt with its characteristic values. In this study it is shown and analyzed the fluctuations at peak discharges and times to peak of unit hydrographs by rainfall storms in a small national basin $8.5\;km^2$ wide are no small. And on assumption that a major factor in the fluctuations of the unit hydrographs in a small basin be rainfall intensity of a rainstorm, both relations of peak discharge and time to peak with rainfall intensity are suggested as exponential functions respectively. In this result although it is a limit of the study in which its result is accompanied with not small dispersion in the peak values of unit hydrograph due to a defect in used data it is sure an averaging regression relation between peak discharge and time to peak with rainfall intensity as identified in this study has hydrological worth from the complementary viewpoint of the theory of unit hydrograph.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.136-140
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• 1999

Measurements of AE signals caused by partial discharges were performed by using an ultrasonic measurement technique to diagonise the electrical treeing deterioration in XLPE cable. We also examined the partial discharge magnitude and AE signals(peak-to-peak) with the increase of the deterioration time. From these results, it was found that AE signal due to partial discharge can be greatly detected at the peak value of positive polarities prior to the breakdown voltages, and the magnitude of AE signals was closely related to the current pulses by the increase of deterioration, and it appeared that AE signals(peak-to-peak) was proportional to partial discharge magnitude. Attenuation and time-delaying characteristics of ultrasonic signals propagated in various polymers sample by using ultrasonic oscillation and receiving systems are also reported as a basic data of ultrasonic measurements in XLPE cable.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.1
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• pp.123-133
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• 1996

From the experimental study of wire-cut Electric Discharge Machining of alloyed tool steel and tungsten carbide, the characteristics such as cutting speed, surface roughness has been observed and evaluated for various conditions. Cutting speed is improved as peak discharge current and wire tension become increased, and gap voltage and spark cycle decreased. Surface roughness can be better when peak discharge current and gap voltage become smaller, or spark cycle and wire tension become larger. Secondary cut is recommended to obtain high precision and good quality.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.346-349
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• 2010

In this study several unit hydrographs by rainfall storms are derived and moving averaged unit hydrograph is extracted from them based on the rainfall-runoff data in a small basin 8.5 $km^2$ wide. And peak discharges and peak times of the unit hydrographs are investigated and reviewed. And then a representative unit hydrograph of the moving averaged one is applied to the linear convolution integration for obtaining the flood discharge hydrograph and peak discharge and time of its result are researched and inspected. Variance in application of the representative unit hydrograph in a basin on assumption of linearity is appeared and this is given as a counterevidence about that the runoff response from rainfall on a basin has nonlinear characteristics. And As a result of application of derived representative unit hydrograph the errors in peak discharge and time are investigated.