• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1999년도 학술대회논문집-국제 전기방전 및 플라즈마 심포지엄 Proceedings of 1999 KIIEE Annual Conference-International Symposium of Electrical Discharge and Plasma
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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.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1999년도 학술대회논문집-국제 전기방전 및 플라즈마 심포지엄 Proceedings of 1999 KIIEE Annual Conference-International Symposium of Electrical Discharge and Plasma
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• pp.141-144
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• 1999

This paper offer fundamental ones about insulation diagnosis with electromagnetic wave, when discharges occurred. To simulate Partial-Discharge(PD), It is used needle-plane electrode in air. As the voltages applied, measure the electromagnetic wave with monopole antenna and analysis its fundamental characteristics, then, acquired data were operated. The results presented as the form of graph, and the magnitude of charge when occurred PD simultaneously. In conclusion, when the magnitude of charge over 100[pC], the electric field strength changed, and then the magnitude of charge and the electric field strength increased samely.

• Journal of Advanced Marine Engineering and Technology
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• 제28권2호
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• pp.338-346
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• 2004

Experimental data on the effect of the variable gravity magnitude, namely microgravity, normal gravity and hyper-gravity, on flow pattern and frictional pressure drop were obtained during co-current air-water flow in a horizontal tube, The flow patterns were found to depend strongly on the gravity magnitude and certain flow pattern were found to depend on the gas superficial velocity. The effect of the gravity magnitude had an effect on the frictional pressure drop only at low flow rates. The present data are used to evaluate some of existing flow pattern transition and pressure drop models and correlations.

• 한국컴퓨터산업교육학회:학술대회논문집
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• 한국컴퓨터산업교육학회 2003년도 제4회 종합학술대회 논문집
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• pp.87-94
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• 2003

Anisotropic diffusion is a selective smoothing technique that promotes smoothing within a region instead of smoothing across boundaries. In anisotropic diffusion, the rate of smoothing is controlled by the local value of the diffusion coefficient chosen to be a function of the local image gradient magnitude. El-Fallah and Gary E. Ford represented the image as a surface and proved that setting the inhomogeneous diffusion coefficient equal to the inverse of the magnitude of the surface normal results in surface evolving speed that is proportional to the mean curvature of the image surface. This model has the advantage of having the mean curvature diffusion (MCD) render invariant magnitude, thereby preserving structure and locality. In this paper, the proposed MCD model efficiently reduces diffusion coefficient at the thin edges using the smoothness of the surface.

• 한국음향학회:학술대회논문집
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• 한국음향학회 2001년도 추계학술발표대회 논문집 제20권 2호
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• pp.41-44
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• 2001

본 논문에서는 음성합성 과정에서 음성유닛을 연결할 때 모음의 결합부분에서 포만트의 불일치로 일어나는 부자연스러운 합성음이 발생되는 문제점을 개선하기 위해서 앞에 오는 음성 유닛과 뒤에 오는 합성 유닛의 포만트 변경에 관한 방법을 제안한다. 요즘에 연구되는 코퍼스 방식에선 에너지와 피치와 음순지속시간 등을 기준으로 유닛을 선택한 후 연결하지만, 스펙트럼의 불일치가 이루어진다. 이런 스펙트럼의 불일치는 음질의 저하를 유도한다. 그래서 앞 음성유닛의 연결부분의 일정부분과 뒤 음성 유닛의 연결부분의 일정부분의 포만트를 천이시켜 일치시켜줌으로써 음질을 향상시켰다. 음성신호를 FFT한 후 magnitude와 phase를 분리한 후 앞 음성의 연결부분의 magnitude와 뒷 음성의 연결부분의 magnitude를 기준으로 linear interpolation한 값을 목표치로 이동하고 다시 합하여 원 신호를 복원하는 방식으로 포만트를 변경시켰다.

• 대한의용생체공학회:의공학회지
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• 제5권1호
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• pp.19-24
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• 1984

In this study, the general characteristics, and theories of cochlear concerning with hearing are examined. Also the digital method is studied in order to analyze with microcomputer on the model equation of basiliar membrane in the cochlear derived from 3-dimensional rectangular block model which is studied by Boer. The method is illustrated for the amplitude characteristics of basiliar momtrane wave velocity. The results obtained are as follows; 1. In the magnitude characteristics, the velocity gradually increases from the stapes, shows the maximum magnitude, and then rapidly decreases to the Helicotrema. 2. The characteristics of 3-dimensional model is located between 1-and 2- dimensional models in the velocity characteristics coefficients, magnitude characteristics, and the pattern of 2-dimensional model shoves the different features from the 1-dimensional and 3-dimensional rectangular block model. 3. In the 3-dimensional rectangular block model, the characteristics of the waveform and the maximum resonant point are same whether Z(X) is linear or nonlinear.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전력기술부문
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• pp.239-242
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• 2001

This paper presents a windows program package for solving security constrained OPF in interconnected power systems, which is based on the combined application of evolutionary programming(EP) and sequential quadratic programming(SQP). The objective functions are the minimization of generation fuel costs and system power losses. The control variables are the active power of the generating units, the voltage magnitude of the generator, transformer tap settings and SVC setting. The state variables are the bus voltage magnitude, the reactive power of the generating unit, line flows and the tie line flow. In OPF considering security, the outages are selected by contingency ranking method. The resulting optimal operating point has to be feasible after outages such as any single line outage(respect of voltage magnitude, reactive power generation and power flow limits). The OPF package proposed is applied to 10 machines 39 buses model system.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
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• pp.347-351
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• 2004

The cryogenic test facility is developed for test of deep groove ball bearings, floating ring seals, materials (steel & copper) for High Pressure Turbopump of liquid rocket engine (LRE). The cryogenic bearing test is performed to evaluate the flow rate of cooling water and the load-carrying capacity of bearings. The cryogenic seal test is performed to evaluate the determination of magnitude of leakages through the seal, a time variation of this magnitude. The test of the materials Pair is performed to evaluate its fitness for operation in the liquid oxygen medium.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1997년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Fall 1997
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• pp.21-26
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• 1997

For 262 locations throughout the southern part of Korean peninsula, intensities of 13 December 1996 Yeongweol earthquake are estimated to make an isoseismal map and investigate attenuation properties in the southern part of Korea. Due to the inherent uncertainties in the estimation of intensities, obtained intensity map show quite scattered pattern of intensity distribution. Estimated intensities range from III to possibly Ⅷ. In case of intensity larger than Ⅵ, considerable damages such as fracturing of walls are reported one of the most significant feature of the intensity map is, considering its magnitude 4.7 reported by KMA, the felt area is appeared to be unusually large covering most of the Korean peninsula except Cheju island. This result indicates ether the magnitude is underestimated or the focus of this earthquake is much deeper. Assuming shallow(less than 10km) intraplate earthquake, we obtained average magnitude 5.6 by using the area encircled by isoseismal contour lines from intensity IV to intensity Ⅶ. This ambiguity can be clarified if more reliable focal depth is estimated by using teleseismic earthquake records in the future.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1997년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 1997
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• pp.57-69
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• 1997

All of the Tsumami which affected severly the east coast of the Korean Peninsula in the years 1741-1993 are caused by earthquakes occurred along the boundary sea of Japan and norther Honshu. These earthquakes with magnitude greater than 7.0 are results of relative movement between the North American Plate and Urasian Plate. The active fault along the boundary of the two plates is attracted by many researchers since the 1983 May earthquake of magnitude 7.7. It is important to anticipate when the next large earthquake will occur and how much it affect the east coast of Korea. Among a few models of spatial seismic gap were proposed for earthquake occurrences accompanying Tsunami, Ishikawas' east-west seismic gap model is the most probable one. There is a tendency that the period between the activities of the active faults becomes shorter. It is expected that a large earthquake of magnitude 7.0 or above will occur along the eastern boundary of Japan Sea at the end of this century and produce Tsunami at the east coast of Korea.