• 지질공학
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• 제30권3호
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• pp.223-235
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• 2020

본 논문에서는 결정질 암반에 건설된 지하연구시설에서 암반의 수리지질특성을 도출하기 위해 수행할 수 있는 현장수리시험의 방법으로 펄스시험을 소개하였다. 아울러 지하연구시설에서 수행한 슬러그시험과 펄스시험의 결과를 비교하여 결정질 암반의 수리지질특성 도출에 대한 펄스시험의 적용 가능성을 평가하였다. 펄스시험과 슬러그시험의 결과를 비교해 볼 때, 매질의 투수성이 낮은 시험구간에서는 그 결과가 매우 유사하게 도출되었지만 투수량계수가 1 × 10^-8 ㎡/s 이상인 구간에서는 약간의 차이를 확인할 수 있었다. 이러한 투수성의 차이는 수리시험 시 적용되는 수리 영향 반경의 차이에서 기인한 것으로 판단된다. 또한 시험결과를 통하여 펄스시험을 투수량계수가 1 × 10^-7 ㎡/s 이상인 시험구간에서 수행할 때, 시험 중 빠른 수두회복 때문에 정확한 시험결과를 도출하기 어렵다는 것을 알 수 있었다. 펄스시험은 비록 투수성이 큰 구간에서 수리지질특성을 도출하기 어렵지만, 저투수성 매질의 암반에서의 수리지질특성을 도출할 때 비교적 빠른 시간에 수리지질특성을 파악할 수 있는 경제적인 시험 방법이라고 제안할 수 있다.

• Journal of Power Electronics
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• 제15권5호
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• pp.1295-1304
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• 2015

In this paper, an approach to extend the life of lead-acid batteries through the elimination of sulfation with "rest time" using the pulse current of a conventional DPV (Differential Pulse Voltammetry) method is discussed. A new rest time without "0" current in "saw-tooth" pattern pulses is proposed to overcome the "0" current (blackout period), which is a shortcoming of DPV. This will enable the proposed method to be used in the loaded state. In the proposed approach, ESSs (Energy Storage Systems) were discharged for 5 h twice per day for 6 months on weekdays. To observe the changes in the lifespan of the systems, for the same period, the changes in the impedances of lead-acid batteries which were being charged e without charging and discharging were measure and compared. This study is focused on determining the effectiveness of lead-acid batteries as ESSs.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2186-2188
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• 1999

A high frequency and energy density pulse transformer is a critical component of a high voltage power supply in a traveling wave tube (TWT) amplifier system. In this paper, processes of design, manufacturing, and test of the transformer are discussed. Primary voltage of the transformer is 240 V. The transformer secondary have two outputs which are 4100 V (Helix) and 2050 V (Collector). Total output power is 860 W. Normal operating frequency of the transformer is 10 kHz. In high energy density pulse transformers, temperature rise is a main problem during its operation. From our study, it was found that resonant current due to leakage inductance and stray capacitance was the main cause of temperature rise. This happens because of the inherently high turn-ratio in high voltage transformers. Solutions to reduce stray components are presented.

• 전자공학회논문지B
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• 제33B권10호
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• pp.139-147
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• 1996

In this study a two-stage fast pulse generaor using magnetic switches is proposed. The scheme consist of a switch, an inductor and two pairs of capacitor and saturable inductors, a linear transformer. The basic principle and the operation are described using a set of given parameters. The main issue of the magnetic pulse genration scheme is the system efficiency. This study focuses on the system efficiency improvement using magnetic switches. The voltage compression ratio, energy transfer with respect to core area are investigated. The output voltage and transferred energy as a function of input voltage are also included. Also, an analysis and experiments are performed to verify the porposed topology by implementing a 10[J] class experimental circuit. The efficiency of the transferred energy a tload side is 82%.

• Nuclear Engineering and Technology
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• 제27권5호
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• pp.784-791
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• 1995

방사선계측에서는 방사선검출기(detector)로부터 나오는 pulse를 처리하는 데 있어서 pulse의 counting 손실이 발생한다. 이 손실을 최소화하거나 보상하기 위한 여러가지 방법들이 제시되어 왔으나, 아직도 절대적인 해답이 확립되지 않은 실정이다. 본 연구에서는 기 제시된 보상알고리즘들을 그 기능을 구현하는 전자회로와 함께 기술하고 특징을 분석하였다. 또한 본 연구를 통해 pulse의 counting손실을 보상하는 한가지 알고리즘 개선방향을 제시하였다.

• 전기의세계
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• 제29권5호
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• pp.321-328
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• 1980

The Q-switching oscillator of TE $M_{00}$ mode was constructed in order to improve the properties of energy focusing and amplification, and prevent laser materials from breakdown. The Q-switching was done by means of electro-optical effect using Glan prism and KDP Pockels cell. Sharp laser pulse of risetime-1 ns and variable pulse width 2-10 ns was obtained from Q-switching laser pulse by PTM method using a laser triggered spark gap (LTSG), Glan prism and Pockels cell. A single ultra-short pulse (picosec order in pulse width) was obtained from mode-locked pulse train in combination of a mode-locked oscillator using saturable dye cell with pulse shaping system using PTM method.d.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.49-51
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• 2007

It is as result that study to apply mini magnet nerve curer in peripheral nervous system disease treatment. Design and embodied action power and Control Unit in cylinder form of magnet roof object firstly. Yielded service area about special quality of probe of roof object cylinder style and treatment area dimension and distance of treatment pulse secondly. Embody pulse forming course energy value by Probe's form by third, could embody treatment pulse by disease. Specially, through a special quality experiment, saved Damping pulse torn and treatment pulse form etc. variously. Lately, embodied this to aid a little in disease treatment that follow that there is no invasion that there is no stimulation by medicine development. Go amplitude treatment pulse (traditional magneto-therapy of greatly great that strong) does curative effect greatest at short time and becomes thought that demand is magnified greatly at the future in this research.

• Journal of Power Electronics
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• 제4권4호
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• pp.237-245
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• 2004

In this paper, a two-switch high frequency flyback transformer linked zero voltage soft switching PWM DC-DC power converter implemented for distributed DC- feeding power conditioning supplies is proposed and discussed. This switch mode power converter circuit is mainly based on two main active power semiconductor switches and a main flyback high frequency transformer linked DC-DC converter in which, two passive lossless quasi-resonant snubbers with pulse current regeneration loops for energy recovery to the DC supply voltages composed of a three winding auxiliary high frequency pulse transformer, auxiliary capacitors and auxiliary diodes for inductive energy recovery discharge blocking due to snubber capacitors are introduced to achieve zero voltage soft switching from light to full load conditions. It is clarified that the passive resonant snubber-assisted soft switching PWM DC-DC power converter has some advantages such as simple circuit configuration, low cost, simple control scheme, high efficiency and lowered noises due to the soft switching commutation. Its operating principle is also described using each mode equivalent circuit. To determine the optimum resonant snubber circuit parameters, some practical design considerations are discussed and evaluated in this paper. Moreover, through experimentation the practical effectiveness of the proposed soft switching PWM DC-DC power converter using IGBTs is evaluated and compared with a hard switching PWM DC-DC power converter.

• Journal of Acupuncture Research
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• 제29권5호
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• pp.17-29
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• 2012

Objectives : The purpose of this study is to find the effects of Sa-Am lung tonifying acupuncture on radial pulse through the parameters difference. Methods : Forty healthy subjects participated in this study, acupuncture group and control group were divided. Compared various parameters of radial pulse between two groups, and the significantly changed 16 parameters ware measured using 3 dimensional pulse imaging system(DMP-3000) before, right after, 30 minutes after, and 60 minutes after acupuncture at Chon, Gwan, Cheok in acupucture group. Results : After lung tonifying acupuncture, radial pulse 16 parameters were showed changes significantly according to the time at each measuring location. 1. Heart rate, T2/T, T5, T5/T and W/T significantly decreased, W significantly increased. 2. Modulus of elasticity significantly decreased in left Cheok. 3. Amplitude of H4 significantly increased in left Gwan and right Cheok. 4. AIx, AIxHR significantly decreased in left Gwan and significantly increased in right Chon. 5. Area of pulse, area of W significantly increased in right Cheok. 6. Pulse energy, energy/min, EIx significantly decreased in left Cheok. 7. Maximum variation time of each parameter is showed different according to the parameter. Conclusions : Lung tonifying acupuncture exerts an influence on radial purse parameters. Further radial pulse change study on various acupuncture treatment is required.

• 한국환경과학회지
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• 제27권6호
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• pp.349-358
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• 2018

In this study, using coke dust from ironwork, the pulse pressure on a pulse air jet bag filter was investigated considering the influence of the pressure loss due to filtration velocity and pressure intervals. The research on the optimal pulse pressure prediction of a pulse air jet type bag filter using coke dust showed the following results. Pressure loss volatility produced by the pulse pressure under low dust concentration(0.5, $1g/m^3$) and low face velocity(1.25 m/min) was less than $10mmH_2O$. This suggests that the pulse pressure has a low impact on the pressure loss. In contrast, pressure loss volatility under high dust concentration($3g/m^3$) and high face velocity(1.75 m/min) was $25mmH_2O$. Therefore, pulse pressure with high dust concentration and high face velocity has a strong influence on the pressure loss volatility, compared to the condition of low dust concentration and low face velocity. The optimal pulse pressure of inlet dust concentration($0.5g/m^3$) was $6kg/cm^2$ under the same face velocity(1.75 m/min). As concentration increased from 1 to $2g/m^3$, the pulse pressure gradually reached $5kg/cm^2$ thus indicating that the pulse pressure($5kg/cm^2$) is pertinent at a high concentration($3g/m^3$). The pulse intervals: 20, 25 and 30 sec, which are relatively longer than 10 and 15 sec, corresponded to high pressure loss volatility produced by the pulse pressure. Furthermore, low pressure loss volatility was noted at $5kg/cm^2$ of the overall pulse pressure.