• 한국산림과학회지
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• 제89권1호
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• pp.1-8
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• 2000

본 연구(硏究)는 Johansen 공적분(共積分) 분석(分析) (cointegration analysis)을 이용하여 캐나다 (Canada) 내(內)의 5개 지역(地域) (Atlantic, Quebec, Ontario, Prairie, British Columbia) 침엽수(針葉樹) 제재(製材) (softwood lumber) 가격(價格)의 일가(一價)의 원칙(原則) (law of one price)이 성립하는지 구명(究明)하는데 그 목적(目的)이 있다. 1987년 10월부터 1998년 11월까지의 월간(月刊) 시계열자료를 이용하였으며 단위근(單位根) 검증법(檢證法) 중 가장 많이 사용되는 Augmented Dickey-Fuller (ADF) 검증법을 이용한 결과 연구에 이용된 모든 수준변수 (level variables)들은 불안정적(不安定的) (non-stationary)이지만 차분변수 (differenced variable)들은 안정적이므로 공적분 분석의 선결조건(先決條件)이 만족되었다. Johansen 공적분 분석결과 캐나다 (Canada) 내(內)의 5개 지역(地域) 침엽수(針葉樹) 제재가격(製材價格)의 일가(一價)의 원칙(原則) (law of one price)이 성립되는 것으로 나타났다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
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• pp.108-111
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• 2002

CIGS film has been fabricated on soda-lime glass, which is coated with Mo film. by multi-source evaporation process. The films has been prepared with thickness of 1.0 ${\mu}m$, 1.75${\mu}m$, 2.0${\mu}m$, 2.3${\mu}m$, and 3.0${\mu}m$. X-ray diffraction analysis with film thickness shows that CIGS films exhibit a strong (112) preferred orientation. Furthermore. CIGS films exhibited distinctly decreasing the full width of half-maximum and (112) preferred peak with film thickness. Also, The film's microstructure, such as the preferred orientation, the full width at half-maximum(FWHM), and the interplanar spacing were examined by X-ray diffraction. The preparation condition and the characteristics of the unit layers were as followings ; Mo back contact DC sputter, CIGS absorber layer : three-stage coevaporation, CdS buffer layer : chemical bath deposition, ZnO window layer : RF sputtering, $MgF_2$ antireflectance : E-gun evaporation

• 한국초등수학교육학회지
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• 제19권1호
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• pp.17-37
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• 2015

이 논문에서는 분수와 소수를 중심으로 미국의 초등학교 교과서인 Harcourt Math와 한국의 2007 개정 교육과정에 따른 초등학교 교과서를 비교 분석하였다. 분석 결과를 요약하면 다음과 같다. 첫째, 미국의 Harcourt Math와 우리나라의 교과서 모두 분수를 전체-부분의 상태를 나타내는 것으로 도입하고 있는데, 미국의 경우가 우리의 경우보다 분수의 생성원으로서의 단위분수 관념이 강하게 나타나있다. 둘째, 당연한 것으로 여길 수 있는 극단적인 양-전체를 나타내는 분수, 분모가 1인 분수-의 표현이 미국의 교과서에서 우리의 경우보다 잘 드러난다. 셋째, 분수와 관련된 용어의 도입방식에 있어서, 우리나라의 교과서는 미국의 경우에 비해서 표현의 관점보다 분류의 관점이 강하다. 넷째, 동치분수와 동치소수의 개념이 미국 교과서(Harcourt Math)에서 우리의 경우보다 자세히 다루고 있다. 끝으로, 미국의 경우는 분수와 소수를 다루는 관점이 우리의 경우보다 좀 더 수학적인 구조에 충실한 것처럼 보인다.

• Journal of Preventive Medicine and Public Health
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• 제50권1호
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• pp.29-37
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• 2017

Objectives: The accurate measurement of geographic patterns of health care utilization is a prerequisite for the study of geographic variations in health care utilization. While several measures have been developed to measure how accurately geographic units reflect the health care utilization patterns of residents, they have been only applied to hospitalization and need further evaluation. This study aimed to evaluate geographic indices describing health care utilization. Methods: We measured the utilization rate and four health care utilization indices (localization index, outflow index, inflow index, and net patient flow) for eight major procedures (coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, surgery after hip fracture, knee replacement surgery, caesarean sections, hysterectomy, computed tomography scans, and magnetic resonance imaging scans) according to three levels of geographic units in Korea. Data were obtained from the National Health Insurance database in Korea. We evaluated the associations among the health care utilization indices and the utilization rates. Results: In higher-level geographic units, the localization index tended to be high, while the inflow index and outflow index were lower. The indices showed different patterns depending on the procedure. A strong negative correlation between the localization index and the outflow index was observed for all procedures. Net patient flow showed a moderate positive correlation with the localization index and the inflow index. Conclusions: Health care utilization indices can be used as a proxy to describe the utilization pattern of a procedure in a geographic unit.

• 한국물환경학회지
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• 제21권2호
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• pp.169-175
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• 2005

This study was carried out to investigate the effects of irrigation water pollution on the yield and grain quality of rice. It acquires fundamental data to set up water quality standards for irrigation and produce agricultural safety products. The correlations of BOD, T-N, T-P, pH, ECw of the irrigation water with yield, grain appearance quality, and the protein content were evaluated. The field and pot experiments were conducted by using Japonica of Oryza sativa L. during 2 years. BOD concentration in irrigation water effects strongly on grain appearance quality and yield of rice. T-N in irrigation water has strong effect on the yield, appearance, and quality of rice. T-P concentration in irrigation water have not any correlation with yield and quality of rice. pH showed strongly negative correlation with maturity ratio(MTR), 1000 grain weight(TGW), and yield of rice(YLD) as r=-0.803~-0.828(p<0.001) and have no effect on the appearance quality of rice. $EC_w$ indicating salt content showed strongly negative correlation with MTR, TGW, number of grains per panicles(NGP), and number of panicles per unit area(NPM) as r=-0.759~-0.798, and with YLD as -0.753.

• 한국지반공학회논문집
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• 제27권12호
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• pp.27-37
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• 2011

강한 지진 발생 시 뒤채움내의 과잉간극수압의 증가에 의해 지반이 액상화 되었을 때, 주변의 액상화 지반보다 작은 단위중량을 가진 지중 매설구조물은 부상하는 현상이 발생한다. 뒤채움에서의 과잉간극수압의 증가와 지중 매설 구조물 부상량의 관계를 설명하기 위해 동적 원심모형 실험을 수행되었다. 본 연구에서는, 매설구조물의 부상현상에 영향을 미치는 요인으로써 직접요인과 간접요인이 실험에 고려되었다. 이러한 요인들 중에, 과잉간극수압비의 증가에 영향을 주는 중요한 요인은 직접요인으로써의 지하수위, 뒤채움의 상대밀도, 그리고 입력 지진가속도의 크기이다. 그리고 이 요인들은 지중 매설구조물의 부상량에도 크게 영향을 주는 것으로 나타났다.

• 한국산업융합학회 논문집
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• 제17권4호
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• pp.234-244
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• 2014

Recently it has been focused that the automobile engine has developed in a strong upward tendency for the use of the high viscosity and poorer quality fuels in achieving the high performance, fuel economy, and emission reduction. Therefore it is not easy to solve the problems between low specific fuel consumption and exhaust emission control at motor cars. In this study, it is designed and used the engine test bed which is installed with turbocharger and intercooler. In addition to equipped using CRDI by controlling injection timing with mapping modulator, it has been tested and analyzed the engine performance, combustion characteristics, and exhaust emission as operating parameters, and they were engine speeds(rpm), injection timing(bTDC), and engine load(%). From the result of an experimental analysis, peak cylinder pressure and the rate of pressure rise were increased, and the location of it was closer toward top dead center according to the increasing of engine speed and load, and with advancing injection timing. The combustion characteristics are effected by fuel injection timing due to be enhanced the mass burned fraction. Using the engine dynamometer for analyzing the engine performance, the engine torque and power have been enhanced according to advancing the fuel injection timing. In analyzing of exhaust emission, there has been a trade-off between PM and NOx with increasing of engine speed and load, and with advanced injection timing. The experimental data are shown that the formation of NOx has increased and PM, vice versa.

• Imaging Science in Dentistry
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• 제38권1호
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• pp.1-5
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• 2008

Purpose: The primary aims of this retrospective study were to compare subjective bone quality and bone quality based on the Hounsfield scale in different segments of the edentulous jaw, and to establish quantitative and objective assessment of the bone quality. Materials and Methods: Twenty eight randomly selected cone-beam computed tomographic (CBCT) scans were analyzed. For evaluation one hundred and twelve edentulous areas were selected. Implant recipient sites were evaluated visually for Lekholm and Zarb classification. The same sites were subsequently evaluated digitally using the Hounsfield scale with Vimplant$2.0^{TM}$, and the results were correlated with visual classification. Data was subject for statistical analysis in order to determine correlation between recorded HU and the regions of the mouth with the Kruskal-Wallis test. Results: The highest unit/mean density value (311 HU) was found in the anterior mandible, followed by 259 HU for the posterior mandible, 216 HU for the anterior maxilla, and 127 HU for the posterior maxilla. These results demonstrate a strong correlation for HU depending on the region of the mouth (p<0.001). The relationship between HU and type 4 bone was found to be significant (r=0.74). Conclusion: Knowledge of the Hounsfield value as a quantitative measurement of bone density can be helpful as a diagnostic tool by using $CBMercuRa6^{TM}$ with $Vimplant^{TM}$ software.

• 세라미스트
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• 제21권2호
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• pp.4-18
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• 2018

Lastly, neuromorphic computing chip has been extensively studied as the technology that directly mimics efficient calculation algorithm of human brain, enabling a next-generation intelligent hardware system with high speed and low power consumption. Three-terminal based synaptic transistor has relatively low integration density compared to the two-terminal type memristor, while its power consumption can be realized as being so low and its spike plasticity from synapse can be reliably implemented. Also, the strong electrical interaction between two or more synaptic spikes offers the advantage of more precise control of synaptic weights. In this review paper, the results of synaptic transistor mimicking synaptic behavior of the brain are classified according to the channel material, in order of silicon, organic semiconductor, oxide semiconductor, 1D CNT(carbon nanotube) and 2D van der Waals atomic layer present. At the same time, key technologies related to dielectrics and electrolytes introduced to express hysteresis and plasticity are discussed. In addition, we compared the essential electrical characteristics (EPSC, IPSC, PPF, STM, LTM, and STDP) required to implement synaptic transistors in common and the power consumption required for unit synapse operation. Generally, synaptic devices should be integrated with other peripheral circuits such as neurons. Demonstration of this neuromorphic system level needs the linearity of synapse resistance change, the symmetry between potentiation and depression, and multi-level resistance states. Finally, in order to be used as a practical neuromorphic applications, the long-term stability and reliability of the synapse device have to be essentially secured through the retention and the endurance cycling test related to the long-term memory characteristics.

• 한국균학회지
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• 제40권3호
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• pp.159-163
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• 2012

노루궁뎅이버섯을 이용하여 성인병 치료와 예방을 위한 기능성식품 개발을 위한 기초자료를 얻기 위해 노루궁뎅이버섯 물 추출물과 유기용매 분획물을 이용하여 성인병관련 생리활성을 확인하였다. 노루궁뎅이버섯 물 추출물은 87.78%의 항산화활성을 나타냈으며, 부탄올 분획물과물 분획물은 87.91%와 92.27%의 높은 활성을 나타냈다. 에틸 아세테이트 분획물은 2.96 plasmin unit의 높은 혈전용해 활성을 보였다. 핵산 분획물로부터 77.67%와 90.53%의 높은 트롬빈 저해활성과 ${\alpha}$-glucosidase 저해활성을 확인하였다. 실험 결과로부터 노루궁뎅이버섯 에틸아세테이트 분획물의 높은 혈전용해 활성과 핵산 분획물의 높은 트롬빈 저해활성과 ${\alpha}$-glucosidase 저해활성은 혈관계질환 치료나 예방을 위한 기능성식품 개발에 이용 가능할 것으로 기대된다.