• 한국운동역학회지
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• 제27권2호
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• pp.149-155
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• 2017

Objective: The purpose of this study was to investigate the effects of three visual conditions (eyes opened, eyes closed, and wearing of a head mounted display [HMD]) on single-leg standing through kinematics and kinetic analysis. Method: Twelve college students (age: $24.5{\pm}2.6years$, height: $175.0{\pm}6.4cm$, weight: $69.2{\pm}5.1kg$) participated in this study. The study method adopted three-dimensional analysis with six cameras and ground reaction force measurement with one force plate. The analysis variables were coefficient of variation (CV) of the center of body mass, head movement, ground reaction force, and center of pressure, which were analyzed using one-way analysis of variance with repeated measures according to visual conditions. Results: In most cases, the results of this study showed that the CV was significantly higher in the order of HMD wearing, eyes closed, and eyes opened conditions. Conclusion: Our results indicated that body sway was the largest in the HMD wearing condition, and the risk of falling was high owing to the low stability.

• 한국전기전자재료학회논문지
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• 제14권8호
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• pp.618-621
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• 2001

Plate-type $\beta$-FeSi$_2$single crystals were grown using FeSi$_2$, Fe, and Si as starting materials by the chemical transport reaction method. The $\beta$-FeSi$_2$single crystal was an orthorhombic structure. The direct optical energy gap was found to be 0.87eV at 300K. Hall effect shows a n-type conductivity in the $\beta$-FeSi$_2$ single crystal. The electrical resistivity values was 1.608Ωcm and electron mobility was 3x10$^{-1}$ $\textrm{cm}^2$/V.sec at room temperature.

• 한국세라믹학회지
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• 제27권5호
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• pp.652-660
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• 1990

Oxidation of Mn-Zn ferrite was made in air at various temperatures ranging from 400$^{\circ}C$ to 1150$^{\circ}C$. Subsequent reduction fo these oxidized samples was also made in air at 1300-1350$^{\circ}C$ where the spinel phase of Mn-Zn ferrite is stable. Morphological observation revealed that the shape of precipitated hematite was plate or lath type on the close-packed habit plane of {111} ferrite which has a definite orientation relationship. The growth of precipitates showed the behavior fo parabolic dependence of the oxidating time. An apparent activation energy for the growth was found to be 125${\pm}$3Kcal/mol. The fact that pores are observed along the precipitates illustrates the oxidation to occur dominantly by the counterdiffusion of cations and ction vacancies. For the reductio reaction pores are found to form at the site once occupied by the precipitates and at the surface. This observation illustrates that the oxygen volitalization from interior region to the surface is the dominant process for the reduction reaction.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.316-320
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• 2008

A light rail transit, using a linear induction motor, is generally composed with reaction plates along railroad track and the three phase primary on the vehicle. This linear induction motor is driven to keep clearance between the primary and the secondary of the ground for preventing any contact. Therefore efficiency and power factor is very low. In addition, the reaction plate installed on the ground throughout entire railway is impossible to keep uniform gap and it may cause system deterioration. In this paper, A rotary-type small-scale model of a linear induction motor for various characteristic analysis is designed. Thrust force, normal force and input current of the model by air-gap variation have been analyzed by using a Finite Element Method (FEM). The effects of air-gap variation on system performance have been considered by analysis results.

• Restorative Dentistry and Endodontics
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• 제33권6호
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• pp.537-544
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• 2008

세균의 검출에 있어서 polymerase chain reaction (PCR) 방법은 기존의 plate counting과 달리 빠르게 세균을 검출할 수 있다. 하지만 세균이 죽은 후에도 DNA는 장기간 존재할 수 있기 때문에, DNA에 기초한 분석은 살아있는 세균과 죽은 세균을 구분할 수 없다. 최근에 DNA extraction전에 propidium monoazide (PMA)를 처리하여 살아있는 세균만 선택적으로 검출하는 방법이 제시되었다. PMA는 손상된 세포막만 통과하여 죽은 세포의 DNA와 빛 노출 하에서 결합하여 PCR이 증폭되는 것을 막는다. Enterococcus faecalis는 근관치료의 실패에 있어서 중요한 원인이 되는 세균으로 제시되어 왔다. 그리고 chlorhexidine (CHX)은 E. faecalis의 제거에 있어서 효과적인 약제임이 밝혀졌다. 이번 실험의 목적은 세균 수의 측정에 있어서, PMA 처리와 real-time PCR 방법의 적용 가능성을 기존의 plate counting과 비교하여 알아보는 것이다. 또한 E. faecalis에 대한 2% CHX의 살균 효과를 PMA 처리 후 real-time PCR 방법을 사용하여 알아보는 것이다. 실험 방법으로 먼저 살아있는 세균과 죽은 세균을 다른 비율로 섞어서 PMA를 처리한 후 real-time PCR을 시행하여 PMA가 빛 노출 하에서 죽은 세균의 DNA와 결합하는 효과를 나타내는지 알아보았다. 다음으로 PMA 처리 후 realtime PCR 방법을 이용하여 살아있는 세균의 양을 측정한 것을 plate counting으로 얻은 CFU와 비교하였다. 마지막으로 2% CHX의 처리시간을 다르게 하였을 때 E. faecalis에 대한 살균 효과를 PMA 처리 후 real-time PCR 방법을 사용하여 알아보았다. 실험 결과로 살아있는 E. faecalis의 비율이 감소할수록 Ct value는 증가하였다. 그리고 PMA 처리 후 real-time PCR 방법을 이용하여 세균의 양을 측정한 것과 plate counting으로 얻은 CFU 사이에는 Optical density (OD) 값이 1.0일 때까지는 상관관계가 있었다. 하지만 OD 값이 1.5일 때는, PMA를 처리한 후 real-time PCR을 시행했을 때 측정된 살아있는 세균의 양이 감소하였음에 반해서 plate counting에 의한 CFU는 계속 증가하였다. 마지막으로 2% CHX을 오래 적용할수록 살아있는 E. faecalis의 상대적인 양이 감소하는 것을 PMA 처리와 real-time PCR 방법을 이용해 확인하였다.

• 한국지반공학회논문집
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• 제21권6호
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• pp.67-79
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• 2005

현장 평판재하시험은 평판에 작용하는 하중과 변위를 동시에 측정하기 때문에 역학적인 특성치 결정의 가능성이 높은 시험방법이다. 그러나 지금까지 평판재하시험으로부터 추정한 탄성계수는 일정 변위를 유발한 하중강도하에서의 지지력계수로부터 구한 하나의 상수값으로서, 이는 포장구조에서 노상이 경험하는 사용하중 단계에서의 대표적인 변형특성치로 결정하기에는 어려움이 있다. 포장설계시 사용되는 회복탄성계수 개념의 변형계수는 중간변형률$(0.01\%\sim0.1\%)$ 영역에서의 값으로서, 현장 노상토의 경우에도 이와 같은 변형률 범위에서의 변형계수를 평가하는 것이 중요하다. 본 논문에서는 노상 현장에서 반복평판재하시험을 이용하여 중간변형률 영역에서의 변형계수를 산정하는 방법을 제안하였다. 이의 신뢰성을 검토하기 위하여 현장에서 크로스홀 시험과 실내에서 공진주시험을 수행하여 전체변형률 영역에서의 현장의 변형특성을 평가하여 평판재하시험 결과와 비교하였다. 두 시험결과 사이의 응력상태를 고려하면 변형률에 따른 변형계수의 값과 경향이 비교적 일치하였고, 제안된 반복식 평판재하시험을통해 현장변형계수의 평가가 가능함을 알 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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• pp.301-304
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• 1997

Effects of volatile impurities on deterioration characteristics of XLPE were investigated. Block type plate with needle-plane electrode and artificial void filled with $N_2$gas or humidity was subjected under high electric field. The dyed region by oxidation reaction around the artificial void filled with humidity was detected before tee initiation. Electrical tree was started from the tip of void filled with $N_2$gas earlier than humidity.

• 한국화재소방학회논문지
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• 제11권3호
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• pp.15-23
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• 1997

In this study, the alumina for gas sensor was prepared by anodic oxidation. It was stable thermally and chemically, and pore diameter and pore distribution was uniform. And the shape of pore was cylinderical. The aluminum plate was carried out by the thermal oxidation, chemical polishing and electropolishing pretreatment. The pore diameter, pore size distribution, pore density and thickness of alumina was observed with the change of reaction temperature, electrolyte concentration and current density. As a results, It was able to use for carrier because alumina which was prepared by anodic oxidationhas uniform pore size distribution.

• 약학회지
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• 제9권3_4호
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• pp.31-33
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• 1965

In the previous papers, it was reported that p-methoxycinnamate showed good antipyretic action when tested on the typhoid-vaccinated rabbits and decreased the ascorbic acid content of the adrenals of rats like other wellknown antipyretics. In the present work, it was shown that p-methoxycinnamic acid exhibited marked analgesic properties. The method employed for testing analgesic effect was modification of that described by Woolfe and Macdonald. Of mice which had been trained and jumped out within 5 seconds on the hot plate of $59{\deg}$, the reaction time was prolonged by subcutaneous injection of its sodium salt aqueous solution. Mean responses were proved to increase linearly with the log doses (from doses 160 mg to 500 mg/kg).

• 대한수의학회지
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• 제10권2호
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• pp.1-5
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• 1970

In these studies the efficracy of plate, tube agglutination and agar-gel precipitin test were compared for the detection of pullorum infected chickens. From all the chickens showing positive reaction in agar-gel precipitin test, Salmonella pullorum organisms were isolated.