• Bulletin of the Korean Chemical Society
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• 제22권11호
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• pp.1231-1235
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• 2001

Pseudotetragonal ZrO0.75S whose space group is P212121 was synthesized and the cell dimensions were a=5.110(2) $\AA$, b=5.110(7) $\AA$, and c=5.198(8) $\AA.$ The space group P212121 seems to be resulted from lowering the symmetry of cubic ZrOS structure with P213 space group by lattice distortion due to the oxygen defects. In the distorted structure, bond shortening between metal-nonmetal by reduction of cell volume and alternation of Zr-Zr distance were observed. Dielectric constant and loss data of the bulk material in temperature range -170 to 20 $^{\circ}C$ and frequency range 50 Hz to 1 MHz showed that there was dielectric transition at around -70 $^{\circ}C$ originated from the relaxation of Zr-S segment. Comparing with ZrO2 exhibited the dielectirc constants, 9.0 at room temperature, ZrO0.75S showed high dielectric constant, k = 200.2 at 100 kHz. The activation energy of relaxation time due to dielectric relaxation of Zr-S was 0.47 eV (11.3 kcal/mole). According to the impedance spectra, ZrO0.75S showed more parallel circuit character between the resistance and capacitance components at the temperature (-70 $^{\circ}C)$ that the Zr-S dielectric relaxation was observed.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 1993년도 한국우주과학회보 제2권2호
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• pp.13-13
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• 1993

245개의 식쌍성에 대한 각운동량과 질량과의 상관 관계를 조사하였다. 이러한 조사 결과 분리형 쌍성계는 Log H=1.40+0.98Log M의 관계를 보였다. 이러한 결과로 보아 분리형과 준분리형 사이의 질량교환에 따른 각운동량이 보전된다는 조건하에서 질량교환에 따른 공전주기 변화의 조건은 성립 할 수 없을 것이다. 한편 12개의 RS CVn형은 분리형으로 undersize Subgiant 형은 준분리형의 상관관계와 일치하는 것으로 나타났다. 한편 접촉형은 분리형과 준분리형 사이에 나타나는 것으로 보아 Lucy와 Robertson and Eggleton등이 제시하는 것은 TRO(thermal relaxtion oscillation)이론에 따른 결과로도 해석 할 수 있을 것이다.

• 한국융합학회논문지
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• 제8권2호
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• pp.291-297
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• 2017

본 연구는 혈관 활성에 도움이 되는 한방차를 개발하고, 섭취효능에 대한 동 서 융합적인 접근 필요성에 대한 기초자료로 사용하고자 하였다. 이에 따라 기미론에 따라 혈관 활성을 가질 수 있는 포공영(Taraxaci Herba), 치자(Gardeniae Fructus), 감국(Chrysanthemum indicum) 및 금은화(Lonicerae Flos)를 선정하여 조성물을 만들고 각각 재료와 조성물의 영양성분, 조성물이 세포활성에 미치는 영향 및 수축혈관에 대한 이완정도를 분석하였다. 기미론적 원리에 따른 한방차 조성물은 체내 열을 제거하고 혈액순환을 촉진할 수 있는 효능을 가지고 있음을 알 수 있었다. 네 가지를 재료를 배합한 조성물은 세포활성에 유익한 영향을 미치고 있음을 확인하였다. 또한 조성물은 수축혈관에 대해 이완효과를 가지고 있었고 조성물의 농도가 높을수록 수축된 혈관의 이완효과가 큰 것으로 관찰되어 이 조성물이 혈관 활성에 긍정적 영향을 주고 있음을 확인하였다. 본 연구는 한방차 조성물의 기미 특성과 현대 영양학의 특성이 융합된 섭취효능을 제시하였다고 사료된다.

• 공업화학
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• 제10권1호
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• pp.160-165
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• 1999

Gel 표준 물질의 핵자기 공명적 완화 성질들이 다공성 매체내 유체의 핵자기 공명적 완화 성질들과 잘 부합될 수 있기 때문에, agarose gel은 다공성 매체내 유체의 성질을 측정하기 위한 표준 물질로 사용될 수 있다. 다공성 매체의 세공도(porosity)와 포화도(saturation)를 결정하기 위한 표준물질의 사용을 논의하였고, gel의 핵자기 공명적 성질에 대한 필요조건들도 제시하였다. 2.0 Tesla에서 측정된 agarose gel의 완화시간은 agarose 농도와 상자기성 불순물의 ($CuSO_4$) 농도 함수로 표시하였고, agarose gel 조성과 완화시간 사이의 실험적 결과를 나타내었다. 세공도 분포에 대한 평균값은 17.7%이고, 이 값은 중량 분석법에 의해 계산된 값과 잘 일치한다. 끝으로, agarose gel을 표준 물질로 사용한 비혼화성 2상 유체실험을 수행하였다. 포화 profile들은 균일한 다공성 매체내에서 일차원 치환실험을 했을 때 계산된 결과와 잘 일치하고 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.322-325
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• 1991

An induction type small size electrostatic actor has been fabricated and tested using different rotor dielectric sheet type materials and 3 phase ac various frequencies ans volatages. It's maximum no-load speed was about 2800rpm at the applied voltage of 3030V and frequency of 47Hz for the rotor material of polypropylene sheet. The motor speed was increased linearly by increasing with an applied volatage and frequency, and it also influenced greatly by the electrical properties of rotor dielectric material of relative dielectric constant, resistivity and relaxtion time

• 동의신경정신과학회지
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• 제16권2호
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• pp.181-188
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• 2005

The purpose of this study is to investigate how much acupuncture treatment and autogenic training can affect to physical, mental relaxation through neurofeedback(Alpha/Theta training). I measured the numerical value of Alpha/H-Beta on the patient with facial tremor due to anxiety during acupuncture treatment and autogenic training, and when that patient wasn't relaxed I gave her feedback. The result shows that autogenic training is always more effective than aucupuncture in making the patient relaxed. On this case, the symptom was not much improved after having the treatments 10 times, but the frequency and intensity of the tremor decresed little. In according to the number of treatments, relaxtion didn't ascend regularly. I think it depends on the patient's condition or surroundings. I am unsatisfied I had only one case in this study and the number of treatments wasn't enough. In the future, much more clinical and statistical studies on herbal, musical, aroma therapies should be needed.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.37-38
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• 2005

Although the law of classical fourier heat conduction predicts the heat conduction phenomena occurred in most engineering fields with a good accuracy, it is also well-known that the conventional fourier law of a heat conduction has an application limit when the heating and cooling are periodic for a short duration or when the heat conduction is analyzed in the extremely low temperature region. This application limit of classical fourier law results from the fact that it assumed the infinite speed of a heat wave. In this study, we investigated the feasibility of whether the molecular dynamics could be used to calculate the speed of a heat wave through a solid. The calculated sound velocity showed a good agrement with the theoretical prediction qualitatively. From the calculated results, we confirmed that the same methodology can be applied the evaluation of the speed of a heat wave.

• 한국자동차공학회논문집
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• 제7권5호
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• pp.154-161
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• 1999

An elastomeric bushing is a device used in automotive suspension systems to cushion the force transmitted from the wheel to the frame of the vehicle. A bushing is an elastomeric hollow cylinder which is bonded to a solid metal shaft at its inner surface and a metal sleeve at its outer suface. The relation between the force applied to the shaft or sleeve and their relative deformation is nolinear and exhibits features of viscoelasticity. Numerical solutions of the boundary value problem represent the exact bushing response for use in the method for determining the force relaxation function of the bushing. The new nonlinear viscoelastic bushing model, which is called Pipkin-Rogers model, is proposed and it is shown that the predictions of the proposed force-displacement relation are in very good agreement with the exact results. This new bushing model is thus very suitable for use in multi-body dynamics codes. The success of the present study for axial mode response suggests that the same approach be applied to other modes, such as torsional or radial modes.

• Journal of Biosystems Engineering
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• 제18권4호
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• pp.402-409
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• 1993

During all mechanical processes rice plants are subjected to verious forces such as natural load of wind and mechanical load of agricultural machines. A force is always accompanied by deformation, which must be either sufficiently great for pressing or sufficiently slight in order to avoid damage. The mechanical behavior of the rice plants is determined by three variables : force, deformation and time. And they must be studied using rheological methods to determine their viscoelastic properties. This study is conducted to experimentally determine the mechanical and rheological properties of the rice stalks subjected to radial load. The force relaxation tests are performed under constant deformation, during which the reduction of forces over time is measured. The mechanical models were developed from the abtained data. The results were as follows : 1. The relaxation behavior of a rice stalk in radial compession may be described by a generalized Maxwell model consisting of 3 Maxwell elements in parallel. 2. Relaxatiom intensity always decreased with increased time of relaxation. 3. The rate of deformation has a significant effect on the relaxation behavior. having increasing pattern with an increase in rate of deformation. 4. The relaxation intensity and residual deformation increased with increased initial load. 5. The relaxtion of the intermediate portion of stalk was bigger tham that of the upper and lower portions.

• 한국자기학회지
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• 제8권2호
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• pp.57-61
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• 1998

비정질 Fe81B13.5C2에서 싸이클로드론을 이용하여 양성자를 조사시키고, 자기 감수율의 주파수 특성을 측정하였다. 초기 감수율 스펙트럼은 전형적인 Debye 형이며, 이완 주파수는 3MHz 정도로 측정되었다. 자구회전에 의한 저주파 감수율은 양성자 조사에 따라 감소하였으나 고주파 감수율은 증가하였다. 조사량에 따른 감수율 이완 주파수 증가는 조사에 의해 국소결합에서 자구회전에 대한 pinning력 증가에 의한 것으로 설명되었다.