• Tunnel and Underground Space
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• v.15 no.4 s.57
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• pp.316-323
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• 2005

As a result of waveform analysis, the separation of waveform found that high frequency well accomplishes but low frequency doesn't accomplish that. The data which measured less than 60 Hz and more than 60 Hz was analysed to examine the relation between cooperating charge and frequency. The measured data of more than 70 Hz was also analysed to consider the characteristics of high frequency.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.210-211
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• 2006

154kV송전용 자기현수애자 오손특성을 구하기 위하여 자체 제작된 챔버 내에서 3개의 자기애자를 현수하여 누설전류파형의 변화를 관찰하였다. 154kV 송전용자기 애자의 신뢰성평가를 위하여 ESDD 레벨에 따른 누설전류 파형 및 최대값 변화양상을 단계적 승압을 통하여 파형을 계측하였다. ESBD 레벨에 따른 누설전류 파형의 최대값이 아크방전의 영향이 없을 경우는 일정한 규칙으로 증가하였고, ESDD레벨이 높아지면서 아크방전의 발생은 주파수 분석을 통한 고조파성분의 변화양상을 볼 수 가 있다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1165-1166
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• 2007

본 논문에서는 우리나라 고속선에서 사용 중인 UM71C 궤도회로의 ESJ(Electrical Separation Joint : 전기적 절연 구간)에서 정상 운행상태에서의 검측데이터 파형과 살수 및 수동살사의 요인에 따른 파형을 비교 및 분석하였다. 차상검측시스템에서 차상신호파형의 왜곡특성을 분석함으로써 지상과 차상간의 인터페이스 분석 및 열차의 안전운행을 확보하기 위한 기초자료로 사용될 수 있을 것이다.

• The Journal of the Acoustical Society of Korea
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• v.11 no.4
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• pp.14-21
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• 1992

The waveform coding is concerned with simply preserving the wave shape of speech signal through a redundancy reduction process. In area of the speech synthesis, the waveform codings with high quality are mainly used to the synthesis by analysis. However, because the parameters of this coding are not classified as either excitation parameters and vocal tract parameters, it is difficult to applying the waveform coding to the synthesis by rule. In this paper, we proposed a new pitch alternation method that can change the pitch periods in the waveform coding by using the cepstrum analysis. Thus, it is possible that the waveform coding is carried out the synthesis by rule in speech processing.

• Tunnel and Underground Space
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• v.18 no.4
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• pp.280-288
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• 2008

Since blast-induced vibration may cause serious problem to the rock mass as well as the nearby structures, the prediction of blast-induced vibration and the stability evaluation must be performed before blasting activities. Dynamic analysis using measurement vibration waveform which is measured by bore hole blasting or test blasting has been increased recently in order to analyze the effect of the blast-induced vibration. The waveform made by bore hole blasting has the similar vibration level and duration to those the waveform of sing hole has. However, there can be a little difference in attenuation characteristics with the blast induced vibration waveform in the field. Through the superposition modeling of single hole waveform, I obtained the vibration waveform on the blasting condition changes and conducted dynamic analysis using this waveform in this study.

• Journal of Biomedical Engineering Research
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• v.21 no.4
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• pp.411-417
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• 2000

This paper describes the analysis of the oscillometric method based on the shape of arterial pressure and proposal of a new algorithm for estimating the blood pressure by computer simulation. In the first step, the arterial pressure model which is able to control the shape of arterial pressure was designed and then we simulated the oscillometric model using both the existing exponential model showing the static arterial pressure-volume relation and the designed arterial pressure model. By analyzing the correlation of characteristic ratio based on the shape of arterial pressure, we could find that the characteristic ratio was not the only standard parameter for estimating systolic and diastolic pressure. We were able to estimate the shape of arterial pressure by computing the correlation of arterial pressure shape with oscillation shape. Finally, we proposed an algorithm which is able to estimate systolic and diastolic pressure according to pressure(Pp) table constructed from the relation of maximum amplitude of oscillation and arterial pressure shape. We tested 60 arterial pressure waveforms having various arterial pressure shape and pulse. As a results, the absolute deviation average values of the estimation of systolic, diastolic and mean pressure were 1.62%, 2.40% and 2.20%, respectively. In conclusions, the proposed algorithm showed the possibility of usefullness in estimating the blood pressure.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.2
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• pp.83-93
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• 2017

A numerical analysis is made of the fluid flow and heat transfer characteristics in the corrugated structure that traps the spent air in the corrugations between impinging jets to reduce crossflow effects on downstream jets in the array. All computations are performed by considering three-dimensional, steady state, and incompressible flow by using the ANSYS-CFX 15.0 code. Averaged jet Reynolds number is 10,000. The oblique angles of impingement jets on the spanwise section are $70^{\circ}$, $80^{\circ}$, $90^{\circ}$, and the oblique angles of impingement jets on the streamwise section are $70^{\circ}$, $90^{\circ}$, $110^{\circ}$. The investigation focuses on the oblique angle influence of impinging jet array on the fluid flow and heat transfer characteristics of a corrugated structure.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.103-105
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• 1999

본 논문은 입력전압 파형을 각각 같은 크기의 정현파, 구형파, 삼각파로 변화시켰을 때, 형광램프의 시동특성ㅇㄹ 어떻게 달라지는 지에 대해 비교 설명한 논문이다. 구형파가 입력으로 주어질 때 램프의 시동특성은 현저하게 떨어져, 시동전압이 크게 상승하는 것을 볼 수 있었으며, 삼각파의 경우는 대체적으로 정현파 입력과 거의 동일한 특성을 나타냈다.

• Journal of Korean Society of Steel Construction
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• v.18 no.1
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• pp.81-91
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• 2006

The corrugated web is a plate that was manufactured with a corrugated shape. It is widely used in bridges, buildings, and culverts. A girder with a corrugated web can be crippled by local, in-plane compressive loads. Due to its high out-of-plane strength, however, a stiffener is usually not needed in trapezoidally corrugated plates, and the corrugated profile of the web can change the boundary condition of the edge load. Some researchers have studied the strength of the partial-edge loading of the trapezoidally corrugated web, but they have not considered the profile of corrugation in their studies. This paper investigates the influence of the corrugate profile. A parametric study was conducted on the shape parameter using the finite-element method. In this parametric study, the relationship between the corrugated shape and the partial-edge strength was also investigated by dividing the partial-edge strength into the web capacity and the flange capacity.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.6
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• pp.43-50
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• 2011

Currently, conventional security methods including IC card or password type method are quickly switched into biometric security systems in various applications and the electrocardiogram (ECG) has been considered as one of novel biometrics way. However, conventional ECG based biometrics used lead II signal which conventionally used for formulaic signal to heart disease diagnosis and it is not suitable for biometrics since it is rather difficult to find consistent features for heart disease patents. To overcome this problem, we developed new biometrics system using ECG lead III signals. For wave extraction, signal peak points are extracted through AAV algorithm. For feature selection, extracted waves are categorized into one of four wave types and total twenty two features including number of vertices, wave shapes, amplitude information and interval information are extracted based on their wave types. Experimental results for thirty-six people showed 100% specificity, 95.59% sensitivity and 99.17% of overall identification accuracy.