• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.627-628
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• 2008

• 한국산림과학회지
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• 제99권5호
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• pp.720-725
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• 2010

On the basis of vegetation data in the 9.12 ha (380 m ${\times}$ 240 m) permanent sample plot of the spruce-fir valley forest in Liangshui National Reserve of Xiaoxing'an Mountains, the study was conducted to evaluate spatial distribution pattern and spatial association by using point pattern analysis for living and dead trees of Larix gmelini by DBH size class. The number of L. gmelini were counted as 59 living stems/ha (6.42 $m^2$/ha of basal area) and 34 dead stems/ha (2.86 $m^2$/ha of basal area). The distributional curve of diameter class exhibited bimodal shape. The analysis of spatial distribution patterns of all living larch stems noted the clumped distribution on the whole. The size of larch aggregates of dead stems was decreased as diameter class was increased. The distribution of dead stems became gradually randomized with decreased clumped size as the scale increased. Living stems and dead stems of the larch had positive spatial association at most of scales, illustrating that the occurrence of mortality of the larch tree was closely related to the distribution pattern of living larch trees.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1807-1812
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• 2007

A bulge testing system was developed to measure mechanical properties of thin film materials. A bulge pressure test system for pressurizing the bulge window of the film and a micro out-of-plane ESPI(Electronic Speckle Pattern Interferometric) system for measuring deflection of the film were included in the testing system developed. For the out-of-plane ESPI system, whole field speckle fringe pattern, corresponding to the out-of-plane deflection of the bulged film, was 3-dimensionally visualized using 4-bucket phase shifting algorithm and least square phase unwrapping algorithm. The bulge pressure for loading and unloading was controlled at a constant rate. From the pressure-deflection curve measured by this testing system, ain-plane stress-strain curve could be determined. In this study, elastic modulus of an electrolytic copper film 18 ${\mu}m$ was determined. The modulus was calculated from determining the plain-strain biaxial elastic modulus at the respective unloading slopes of the stress-strain curve and for the Poisson's ratio of 0.34.

• Restorative Dentistry and Endodontics
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• 제14권1호
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• pp.199-204
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• 1989

The purpose of this study was to observe the anodic polarization curve from 4 kinds of low copper amalgam (Fine cut alloy, Spheralloy, Aristalloy and Amalcap) and 4 kinds of high copper amalgam (Dispersalloy, Sybraloy Orosphere and Tytin) obtained by using the potentiostat. The specimen made as the direction of manufacturer was stored at room temperature for about 7 days. The standard surface preparation was routinely carried out. The 0.9% saline solution was used as electrolyte in pH 6.8-7.0 at $37^{\circ}C$. The open circuit potential was determined after 30 minutes' immersion of specimen. The scan rate was 1mV/sec and the surface area of amalgam exposed to the solution was 0.785$cm^2$ for each specimen. All potentials reported are with respect to Ag/AgCl eelctrode. The following results were obtained. 1. The corrosion potential of high copper amalgams was higher than one of low copper amalgams, and the current density of high copper amalgam was lower than one of low copper amalgams. 2. The low copper amalgams had the similar pattern of polarization curve, but the high copper amalgams had the different pattern one another. 3. The polarization curve of Orosphere amalgam which is the admixed type was similar to one of low copper amalgam.

• The Korean Journal of Physiology
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• 제23권2호
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• pp.291-299
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• 1989

Na and Ca effects on contracture were studied in order to estimate Na/Ca exchange ratio in the isolated atrial muscle of the rabbit. All experiments were performed in tris-buffered Tyrode solution which was being aerated with 100% $O_2\;and\;kept\;at\;37^{circ}C$. To load intracellular $Na^+,\;10{-6}M$ ouabain or K-free solution were used. Contractures were induced by brier exposure of atrial muscle to Tyrode solution containing various concentrations of Ca or of Na. The results obtained were as follows: 1 ) Increasing the extracellular Ca concentration, the amplitude of contracture also increased and was maximum at 8 mM Ca-Tyrode solution. 2) The relationship between extracellular Ca concentrations and relative amplitude of the contractures showed hyperbolic pattern. By using Hill plot, the line has the slope of 1 12 which means the number of Ca binding sites of the carrier in the cell membrane. 3) The amplitude of the contracture was maximum in 0 mM Na-Tyrode solution and decreased in dose dependent manner when the Na concentration increased. 4) When the relationship between extracellular Na concentrations and the amplitude of contractures was expressed as dose-response curve, the curve showed sigmoid pattern. The line with the slope of 2.82 was obtained by using Hill plot. 5) From above all the results, it is suggested that exchange ratio of Na and Ca via Na/ca exchange system in the atrial muscle of rabbit could be 3:1 approximately.

• 한국인구학
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• 제25권2호
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• pp.107-138
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• 2002

여성들의 경제활동 상태는 '가족주기'와 같은 '생애과정'과 밀접히 관련되어 있기 때문에, 경력단절 경향이 강하다. 이 연구는 한국여성의 취업유형을 규명하는 데, 특히 여성들의 생애과정 씨퀀스(sequence)가 갖는 효과를 중심으로 여성들의 취업 이행 과정을 분석하고 있다. 여성들의 경제활동상의 지위 변화에는 과거의 일회적인 사건의 효과 이상으로 과거 생애과정에 축적된 연계의 효과가 중요하기 때문이다. 이 연구의 연구가설은 두 가지이다. 첫 번째 연구가설은, 생애과정 씨퀀스별로 구분되는 여성들의 네 개의 취업경력 유형들 사이에 유의미한 사회.인구학적 차이가 있을 것이라는 점이다. 두 번째 연구가설은, 생애과정 씨퀀스의 배열 순서에 따라 여성들의 취업 이행 과정은 매우 다를 것이라는 점이다. 이 연구가설을 검증하기 위해서 여성취업실태조사자료 가운데 취업력 및 생활사에 대한 종단적 자료를 일원변량분석 및 사건사분석(event history analysis)방법으로 분석하였다. 분석 결과, 취업경력 유형에 따라 구분된 '연속취업형', '불연속취업형', '비경제활동형', '결혼후 퇴장형'의 네 집단간에는 연령, 학력, 자격증 소지 여부, 부모의 인적자본, 건강 상태 등에서 유의미한 차이가 존재함을 발견하였다. 또한 생애과정 씨퀀스의 배열 순서에 따라 구분된'취업후 결혼형'과'결혼후 취업형'은 취업 진입과 취업 단절 행위에서 매우 구별되는 집단임을 확인하였다. 이와 같은 분석 결과를 통해서, 여성들 내부의 경제활동상의 이질적인 집단의 구분과 각 집단 내부 여성들의 다양한 취업 경로를 규명하는 데, 생애과정 씨퀀스가 중요한 설명변수로 작용함을 경험적으로 입증하였다.

• Journal of Astronomy and Space Sciences
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• 제36권2호
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• pp.75-86
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• 2019

UV Psc is a typical RS CVn type system undergoing dynamic chromosphere activity. We performed photometric observations of the system in 2015 and secured new BVR light curves showing well-defined photometric waves. In this paper, we analyzed the light curves using Wilson-Devinney binary code and investigated the orbital period of the system. The combination of our light curve synthesis with the spectroscopic solution developed by previous investigators yielded the absolute parameters as: $M_1=1.104{\pm}0.042M_{\odot}$, $R_1=1.165{\pm}0.025R_{\odot}$, and $L_1=1.361{\pm} 0.041L_{\odot}$ for the primary star, and $M_2=0.809{\pm}0.082M_{\odot}$, $R_2=0.858{\pm}0.018R_{\odot}$, and $L_2=0.339 {\pm}0.010L_{\odot}$ for the secondary star. The eclipse timing diagram for accurate CCD and photoelectric timings showed that the orbital period may vary either in a downward parabolic manner or a quasi-sinusoidal pattern. If the latter is adopted as a probable pattern for the period change, a more plausible account for the cyclic variation may be the light time effect caused by a circumbinary object rather than an Applegate-mechanism occurring via variable surface magnetic field strengths.

• Geomechanics and Engineering
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• 제23권6호
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• pp.575-585
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• 2020

In this numerical study, the 2D dynamic behavior of a clayey basin and its effect on damage pattern over basin edge are investigated. To attain this goal, a fully nonlinear time domain analysis method has been applied. Then, the fragility curves of the considered two typical industrial structures for that certain point are estimated using the acceleration time histories recorded at each surface point. The results show that the use of the damage related parameters in site effect analyses, instead of amplification curves, can yield more realistic estimation of the basin dynamic response. In a distance about 150 m from outcrop at the basin edge, the differences between fragility curves increase when increasing the distance from outcrop with respect to the reference rock site. Outside this region and towards the basin center, they tend to occur in rather single curves. Furthermore, to connect the structural damage to the basin edge effect, the earthquake demand value at different points for two typical structures was evaluated. It was seen that the probability of occurrence of damage increases over 250 m from outcrop, while the effect of the basin edge was limited to 150 m in case of the basin edge evaluation by using fragility curves.

• 한국광학회:학술대회논문집
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• 한국광학회 2000년도 제11회 정기총회 및 00년 동계학술발표회 논문집
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• pp.192-193
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• 2000

We studied the characteristics and fabricated the plano-convex refractive microlenses using the thermal reflow method. The exposed resist was resolved in a standard developing process. The remaining resist of circle pattern was melted in an oven 12$0^{\circ}C$ to 15$0^{\circ}C$. The shape of the melted resist microlenses is ruled by surface tension. Diameter and hight of the fabricated microlenses were 250${\mu}{\textrm}{m}$ to 325${\mu}{\textrm}{m}$ and 15${\mu}{\textrm}{m}$ to 22${\mu}{\textrm}{m}$, respectively. The surface profile was calculated using data curve-fitting method with circle equation. The optical characteristics was analysed using optical simulation program.

• Journal of the Korean Statistical Society
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• 제5권2호
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• pp.119-127
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• 1976

By examining Table 1, it is confirmed that the two model fertility scheduels for 1960 and 1975 are close agreement with the census data in Korea. The declines of age-specific fertility are more remarkable among older women than among younger, as exhibited in Table 3 and Fig. 2. A merit of this fitted model schedule as compared to fitted conventional frequency distributions such as the Pearson Type III curve, is that the model schedule incorporates combinations of intuitively understandable demographic factors. The value of m, a measure of fertility control, increased remarkably from 0.531 in 1960 to 2.429 in 1975. Considering the fact that the average value of m for forty-three schedules shown in the 1965 Demographic Yearbook was 1.0, and the value of m in England and Wales for 1965 was 1.91, the recent level of fertility control in Korea may be considered higher than generally believed.