• 한국자연치유학회지
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• 제11권2호
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• pp.116-122
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• 2022

배경: 복식호흡 수련이 수면이나 혈중 산소농도에 미치는 연구는 아직도 미비하다. 목적: 본 연구는 50대 여성들에게 복식호흡 수련후에 혈중 산소 포화도에 미치는 영향과 맥박의 변이, 불면증 심각성 변화, 수면 전 각성의 변화, 한국판 수면에 대한 역기능적 신념 및 태도에 미치는 영향을 조사하는 것이었다. 방법: 대상자들에게 12주간 숨(호흡) 수련을 주 3회기 36회 호흡법을 통해 사전 및 사후 변화를 조사하였다. 결과: 호흡수련후 맥박 수의 변화에는 유의성이 없는 것으로 평가되었다. 산소포화도는 실험군에서는 호흡치유 사전에 93.60 SpO₂%, 호흡수련 후에는 96.5 SpO₂%로 증가하여 유의성이 있었다(p < .002). 불면증 심각성 척도와 수면에 대한 역기능적 신념은 호흡수련 하기 전보다 후에 감소치가 유의성이 있었다(p < .000). 결론: 대상자들에 대한 호흡수련이 불면증, 맥박과 산소포화도에 효과가 있어서 건강에 도움 되는 것으로 평가한다.

• 지구물리와물리탐사
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• 제13권4호
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• pp.388-396
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• 2010

이 논문은 전기비저항 관측을 이용한 이산화탄소($CO_2$)의 지중저장 모니터링 및 포화도 산정에 관한 실험 연구로, 균질한 시료 및 불균질한 시료에 대해 초임계$CO_2$와 염수의 주입 및 반복 실험을 통하여 전기비저항의 변화를 고찰하고 이로부터 전기비저항 지수를 이용하여 $CO_2$ 포화도를 추정하였다. 두 암석시료에 대해 실험한 결과, 시료 내부의 공극구조에 따른 영향과 함유된 점토 광물의 영향이 포화도 산출하는데 있어서 영향을 미치고 있음을 확인하였다. 이러한 결과는 실제 저류층에서의 전기비저항에 따른 $CO_2$ 포화도 추정의 정량적 평가에 있어 유용한 기초 자료가 된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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• pp.55-57
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• 1998

A finite element analysis for a synchronous reluctance motor (SynRM) is presented with emphasis on the effect of saturation and iron losses. Preisachs model, which allows accurate prediction of iron losses, is adopted in this procedure to provide a nonlinear solution. This technique provide significant properties of proposed SynRM under the magnetic saturation and iron losses effect.

• Journal of Power Electronics
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• 제15권5호
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• pp.1264-1273
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• 2015

An inverter output power control based power factor correction (PFC) strategy is being extensively used for permanent magnet synchronous motor (PMSM) drives in appliances because such a strategy can considerably reduce the cost and size of the inverter. In this strategy, PFC circuits are removed and large electrolytic DC-link capacitors are replaced with small film capacitors. In this application, the PMSM d-q axes currents are controlled to produce ripples, the frequency of which is twice that of the AC main voltage, to obtain a high power factor at the AC mains. This process indicates that the PMSM operates under periodic magnetic saturation conditions. This paper proposes a back electromotive-force (back-EMF) estimator for the high-speed sensorless control of PMSM operating under periodic magnetic saturation conditions. The transfer function of the back-EMF estimator is analyzed to examine the effect of the periodic magnetic saturation on the accuracy of the estimated rotor position. A simple compensation method for the estimated position errors caused by the periodic magnetic saturation is also proposed in this paper. The effectiveness of the proposed method is experimentally verified with the use of a PMSM drive for a vacuum cleaner centrifugal fan, wherein the maximum operating speed reaches 30,000 rpm.

• Child Health Nursing Research
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• 제13권3호
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• pp.299-307
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• 2007

Purpose: To investigate the effect of nonnutritive sucking(NNS) on the heart rate, oxygen saturation, and behavioral state of premature infants. Method: From December 15, 2004 to February 15, 2005, 20 premature infants hospitalized in the neonatal intensive care units were assigned to an experimental group (10), or a control group (10). Circular pacifiers for premature infants (Johnson, U.S.A.), which had been packed with $2{\times}2$ gauzes to create a vacuum, were used for 5 minutes, one hour after feeding for 5 days. Heart rates and oxygen saturation were checked every minute for 10 minutes once a day and behavioral states were monitored through video recording at the same time. Results: Changes in heart rate, oxygen saturation and behavioral state were found to show significant differences between the experimental group and the control group according to the point in time, and interactions were found between the group and the point of time. However, for behavioral state, no significant difference was found between the experimental group and the control group after the NNS was removed. Conclusion: From the results of this study it is possible to conclude that NNS is a positive intervention to bring about increased oxygen saturation and soothed behavioral state for premature infants.

• 한국결정성장학회지
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• 제12권6호
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• pp.288-291
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• 2002

We developed a new RF indirect-heating LPE furnace. The thermal gradient of our newly developed furnace is less than that of direct heating, and is as gentle as that of the resistance-heating LPE furnace. With this new furnace, the heating and/or cooling is faster than that of the resistance-heating furnace. Impurity-doped YIG film was grown from a $PbO-B_{2}O_{3}$, based flux on a (111) GGG substrate. To study the effect of the impurities on the MSSW threshold power and the saturation response time, we used two microstrip lines to excite and propagate the MSSW at 1.9 GHz. The MSSW threshold power and saturation response time was found to be related to the $\Delta$H.

• 대한기계학회논문집
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• 제19권8호
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• pp.1999-2011
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• 1995

Computer simulation was conducted to study performance characteristics of air-cooled condenser of a double effect absorption heat pump with variations of saturation pressures and mass flow rates of the refrigerant ; volume flow rates, relative humidities and temperatures of the air The vertically installed condenser had the staggered tube array with continuous plate fins of wavy type. When the saturation pressure of the condenser was decreased from 760 torr to 20 torr, heat transfer rates and condensing rates of refrigerant were decreased. If excess refrigerant flows in the condenser, the pressure and saturation temperature of the condenser were increased which makes the refrigerating capacity of an absorption heat pump reduced.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전력기술부문
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• pp.50-52
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• 2002

Distance relays need accurate current and voltage for determining the trip ignition. Therefore we must analyze nonlinear phenomena which cause distortion in signals first of all. This paper presents the effect of some distortion(arcing fault and current transformer saturation) in power system. The saturation of a current transformer distorts input current of a distance relay and arcing faults make current and voltage to be changed. This paper describes modeling methods of a current transformer and arcing faults, and describes the simulation result of two distance relay algorithms (discrete fourier transform and modified differential equation methods)

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 2차
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• pp.104-112
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• 2010

The thermal influential factor of energy pile system is investigated by considering the seasonal effect, saturation of ground, and fluid velocity based on the finite volume method. Analysis includes the evaluation of thermal resistance and corresponding heat exchange rate for each case. It is shown that the efficiency of heat exchange rate is more pronounced with higher fluid velocity due to the larger number of circulation for a given period. Through the parametric studies, it is also found that the degrees of saturation a little influenced thermal effect during 8 hours of operational scenario.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 추계종합학술대회
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• pp.349-352
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• 2001

본 논문에서는 1400nm 대역에서 이득을 갖는 TDFA의 증폭 특성과 과도응답 특성을 이론적으로 해석하였다. 수치모델은 밀도반전의 형성과정, 여기파워, 증폭기를 따라 변화하는 신호파워를 포함한다. 본 이론해석의 결과는 광섬유증폭기의 이득 포화와 복구시간을 예측할 수 있게 해주고, 펌핑율과 포화 율이 이득의 포화와 복구시간에 미치는 영향을 예측할 수 있게 한다.