• 정보교육학회논문지
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• 제21권2호
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• pp.183-190
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• 2017

본 연구는 스마트 블렌디드 수업 전략이 역사수업에서 어떤 효과가 나타나는지에 대한 분석을 하였다. 수업전략의 효과성은 학업 성취도와 학습 흥미도로 설정하고 역사수업에 참가한 초등학생들을 대상으로 제안된 스마트 블렌디드 수업전략을 적용하여 비교집단과 비교하였다. t-검증 결과, 제안된 수업전략이 학생들의 학업성취도 및 학습흥미도에 긍정적인 영향을 주었다. 또한 질적 분석을 통하여 학생들이 수업의 이해도가 높아졌고 집중력이 향상되는 효과를 보여주었다.

• 천문학논총
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• 제30권2호
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• pp.359-361
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• 2015

We use the millennium simulation for studying the evolution of groups of galaxies over time. We find fossil and non-fossil groups as well as old and young groups at redshift z = 0 and follow them back in time to investigate the evolution of their parameters, such as mass assembly, luminosity gap and halo mass concentration. We find that fossils assemble a larger fraction of their mass at z = 0 than controls. The magnitude gaps between fossil and non-fossil groups are not the same because of major and minor mergers, in old and young groups as well. We also find that WMAP1 and WMAP7 cosmologies lead to the same evolutionary history for fossil and control groups.

• Earthquakes and Structures
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• 제5권3호
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• pp.277-296
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• 2013

Margin of safety against potential of progressive collapse is among important features of a structural system. Often eccentricity in plan of a building causes concentration of damage, thus adversely affects its progressive collapse safety margin. In this paper the progressive collapse of symmetric and asymmetric 3-story reinforced concrete ordinary moment resisting frame buildings subjected to the earthquake ground motions are studied. The asymmetric buildings have 5%, 15% and 25% mass eccentricity. The distribution of the damage and spread of the collapse is investigated using nonlinear time history analyses. Results show that potential of the progressive collapse at both stiff and flexible edges of the buildings increases with increase in the level of asymmetry in buildings. It is also demonstrated that "drift" as a more easily available global response parameter is a good measure of the potential of progressive collapse rather than much difficult-to-calculate local response parameter of "number of collapse plastic hinges".

• 교육시설 논문지
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• 제20권6호
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• pp.31-40
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• 2013

The purpose of this study is to understand the meaning of architectural history of designated cultural properties of modern educational facilities through the analysis of its status. This study considerate acceptance and evolution of modern educational facilities during the about seventy years from 1895 to 1965. Also, this study analyzes items that is distribution of construction and designation year, regional groups, and status of main structure material, status of conservation and utilization of facilities, its characteristics of architectural style. In this study, the result of analysis show that most analysis items of investment buildings are tend to biased and concentration to one direction. Accordingly, designated cultural properties of modern educational facilities are weakly express architectural representation and symbolism in the period of modern educational acceptance.

• Ocean Science Journal
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• 제42권1호
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• pp.49-59
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• 2007

Besides empirical algorithms with the blue-green ratio, the algorithms based on fluorescence are also important and valid methods for retrieving chlorophyll-a concentration in the ocean waters, especially for Case II waters and the sea with algal blooming. This study reviews the history of initial cognitions, investigations and detailed approaches towards chlorophyll fluorescence, and then introduces the biological mechanism of fluorescence remote sensing and main spectral characteristics such as the positive correlation between fluorescence and chlorophyll concentration, the red shift phenomena. Meanwhile, there exist many influence factors that increase complexity of fluorescence remote sensing, such as fluorescence quantum yield, physiological status of various algae, substances with related optical property in the ocean, atmospheric absorption etc. Based on these cognitions, scientists have found two ways to calculate the amount of fluorescence detected by ocean color sensors: fluorescence line height and reflectance ratio. These two ways are currently the foundation for retrieval of chlorophyll-a concentration in the ocean. As the in-situ measurements and synchronous satellite data are continuously being accumulated, the fluorescence remote sensing of chlorophyll-a concentration in Case II waters should be recognized more thoroughly and new algorithms could be expected.

• 한국안광학회지
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• 제9권2호
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• pp.371-380
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• 2004

안경의 역사는 인쇄술의 발전과 함께 시작되었다고 할 수 있다. 맨 처음 안경은 가죽으로 만들어 졌다. 그 이후 나무나 뿔, 혹은 뼈로서 안경테를 만들고, 수정이나 유리로 렌즈를 만들어 끼운 단 안경 두 개의 대못으로 연결시킨 대못안경(Riveted Spectacles)이 개발된 이래 안경테는 수많은 스타일로 변화되어 왔다. 그 후 코다리(Bridge)의 개발, 다리 (Temple)의 등장으로 오늘날의 안경의 형태가 나오기 시작했고, 오늘날 다양한 디자인과 소재들이 개발되면서 실용적이며 안경의 스타일에 이르게 되었다. 그럼으로, 안경제조업체와 안경디자이너들은 새로운 안경패션 트랜드를 리드할 수 있는 디자인 개발에 주력하고 있다. 본 연구에서는 현재의 안경테가 있기 까지 역사적 발달과정을 통한 다양한 스타일의 안경테를 분석하고, 디자인의 목적인 형태와 기능의 관점에서 안경디자인의 방법적 요소를 조사해보고자 한다.

• 설비공학논문집
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• 제13권7호
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• pp.627-636
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• 2001

This paper presents a numerical analysis of the emission process of volatile organic compound(VOC) from building material and its diffusion in a room. A polypropylene styrene-butadiene rubber(SBR) floor plate is chosen as the emission source of VOC. This study investigates spatial concentration distributions and time history of room-averaged VOC concentration for both with and without flushing. The results of this study show that for calculation based on ten-days period the room averaged VOC concentrations with and without flushing are quite different. the results thus suggest the need of flushing for new buildings.

• Journal of the Korean Wood Science and Technology
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• 제47권2호
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• pp.178-188
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• 2019

Licorice, which has an extensive history of use as an herbal medicine, has been suggested to have oral health benefits. However, to date, no systematic study has been conducted on the preparation method of licorice extracts for oral health. In this study, licorice extracts prepared using water and ethanol were investigated for its ability to inhibit the biofilm formation of Streptococcus mutans. The licorice extract prepared with around 60% ethanol effectively inhibited the biofilm formation of S. mutans. Licorice extracted with 50% ethanol almost completely inhibited the biofilm formation at 1.5 g/L of licorice extract. This inhibitory activity was confirmed in a microplate assay and a flow cell system. Glycyrrhetic acid was extracted from licorice effectively with 60% ethanol concentration. The strong inhibitory activity of glycyrrhetic acid and the synergistic inhibition with glycyrrhizin on biofilm formation were suggested as major reasons for a concentration-specific extraction. These results suggest that licorice extract prepared using around 60% ethanol effectively inhibits the biofilm formation of S. mutans.

• 생물정신의학
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• 제3권2호
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• pp.258-261
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• 1996

Objective : Several studies hove suggested that reduction of cholesterol concentration and low cholesterol level increases suicide, homicide, and depression. The authors sought to determine whether low cholesterol is associated with a history of suicidal attempts among major depression patients. Method : The subjects were 105 patients with major depression, diagnosed according to the DSM-III-R criteria, and 105 age, sex matched healthy controls. Blood was token following overnight fast and serum cholesterol concentration were measured by a enzymatic method Results : The serum cholesterol level was significantly lower in the patients with major depression than in healthy controls($180.4{\pm}43.4mg/dl$ vs $199.7{\pm}35.8mg/dl$). And the serum cholesterol level was significantly lower in major depression patients with suicidal attempt than in major depression patients without suicidal attempt($156.7{\pm}38.2mg/dl$ vs $ 187.8{\pm}42.5mg/dl$) Conclusion : It is hypothesized that low cholesterol level is associated with depression by modifying the serotonin metabolism and the production of interleukin-2, low cholesterol concentration should be further investigated as a potential biological marker of suicidal risk in major depression. Prospective study with serial cholesterol determinations should be done.

• 한국임상수의학회지
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• 제22권1호
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• pp.70-73
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• 2005

A 9-year old female Shih Tzu dog was presented to the Veterinary Medical Teaching Hospital of Seoul National University with a history of chronic intermittent anorexia and vomiting of 4-year duration. She visited 3 years ago with the same clinical signs but has not been treated regularly due to waxing-waning course. On the physical examination, no specific findings were found. CBC, serum chemistry, radiography, ACTH stimulation test, evaluation of serum T4 and TSH concentration were performed. Hypoadrenocorticism was diagnosed with the ACTH stimulation test. And then, secondary hypoadrenocorticism was diagnosed with ACTH stimulation test, pre-ACTH aldosterone concentration, endogenous ACTH concentration. As electrolyte concentrations were normal, glucocorticoid (0.15 mg/kg bid PO) alone was administered. She has recovered from the clinical signs and has been doing well. It is suggested that the differentiation of secondary hypoadrenocorticism from primary hypoadrenocorticism is important as the secondary hypoadrenocorticism occurs rarely and the symptoms are non-specific with normal electrolyte concentrations.