• 아동학회지
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• 제23권6호
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• pp.103-119
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• 2002

In this investigation of the effectiveness of the Project Approach Method the 32 4-to 5-year-old subjects (16 each in the experimental and comparative groups) were pre-tested before the Project Approach Method was applied (23 times over 7 weeks) in the experimental group while the comparative group had science activities using standard unit methods of instruction. Then, all the children had a posr-test. Data were analyzed by t-test and ANCOVA. Results showed differences between the experimental group and the comparative group in their scientific problem solving ability. Specifically, effects were found on 14 sub-factors, but no difference were found on 3 sub-factors.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
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• pp.99-102
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• 2005

This paper presents test results on strengthening details of reinforced concrete beams strengthened with near-surface mounted(NSM) CFRP rod and strip. A total of 8 specimens have been tested. The specimens can be classified into the same strengthening area group and the different spacing group. For the same strengthening area group, experimental results revealed that specimens strengthened with NSM CFRP strips improved the flexural capacity of RC beams. For the different spacing group, the flexural capacity of RC beams was almost the same, but it was different in case of NSM CFRP rods.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
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• pp.174-175
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• 2006

본 논문에서는 상압에서 RF파워에 의해 플라즈마 바늘(plasma needle) 에서 발생된 마이크로 플라즈마를 이용한 바이오 실험에 대한 결과를 제시한다. 마이크로 플라즈마는 그 크기가 수 mm에서 수백 마이크로미터 크기의 플라즈마를 지칭하는 단어로써 다양한 전원에 의해 구동된다. 바이오 응용을 위한 저온 플라즈마는 세포 활동을 저해하지 않도록 온도가 적절히 제어되어져야만 한다. 본 논문에서는 플라즈마 온도를 40도 이하로 조절하도록 외부 인가 파워를 조절하였다. 플라즈마의 특성을 알기 위해서 기초적인 가스 스펙트럼에 대한 조사도 수행하여 아르곤 (Ar) 과 헬륨 (He) 의 결과를 저압의 결과와 비교하였다. 또한 작은 크기 때문에 플라즈마의 관찰이 용이하지 않으므로 모델링을 통한 시뮬레이션으로 플라즈마 거동 및 분포를 계산하였다. 시뮬레이션을 통하여 플라즈마에 대한 정보 및 향후 시스템 개선에 사용할 수 있다. 마이크로 플라즈마를 이용하여 수행한 기초적인 바이오 실험의 예로써 흑색종 (피부암세포, meianoma)에 대한 플라즈마 및 전기장의 효과를 제시한다.

• Geomechanics and Engineering
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• 제11권5호
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• pp.691-711
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• 2016

In this study, the uplift capacity of anchor plates embedded in sand was investigated by conducting model tests. Square shaped anchors were used in the tests and parameters such as relative density of sand, embedment ratio (H/B), spacing ratio between anchors (S/B) and anchor configuration affecting the uplift capacity were investigated. Breakout factor and group efficiency which are dimensionless parameters were used to show the results. A series of finite element analyses and analytical solutions were additionally performed to ascertain the validity of the findings from the laboratory model tests and to supplement the results of the model tests. It can be concluded that the embedment depth in dense sand soil condition is the most important parameter with respect to the other parameters as to influencing the uplift capacity of group anchors.

• Advances in aircraft and spacecraft science
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• 제6권1호
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• pp.69-86
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• 2019

This paper discusses the use of the Digital Image Correlation (DIC) technique for the displacement and strain measurements of a wet lay-up composite wing. As opposed to classical strain gages, DIC allows to conduct full field strain analysis of simple to complex structural parts. In this work, wing-up bending tests and measurements of the composite wing of the Dardo Aspect by CFM Air are carried out through an ad-hoc test rig and the Q-400 DIC system by Dantec Dynamics. Also, the results are used to validate a finite element model of the structure under investigation.

• 천문학회보
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• 제46권2호
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• pp.67.2-67.2
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• 2021

We present preliminary results on the chemical and kinematic analysis of accreted and heated metal-rich (-1.0 < [Fe/H] < -0.3) stars in the Galactic disk. These stars are in the ranges of e > 0.7, -100 < V_𝜙 < 100 km/s, and |Z| < 3 kpc, and are presumably heated (accreted) by (from) past merger events such as Gaia Enceladus and Sausage (GSE). These stars are largely separated into two groups based on the level of [α/Fe] and radial velocity dispersion. The first group has low [α/Fe] and high radial velocity dispersion, and the second group shows high [α/Fe] and low radial velocity dispersion. We propose that the first group of stars are accreted from the GSE galaxy, whereas the second group of stars are dynamically heated by the GSE merger event.

• International Journal of Internet, Broadcasting and Communication
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• 제15권4호
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• pp.115-127
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• 2023

In this paper, we have undertaken a comprehensive investigation into the current state of anti-drone technology due to the increasing concerns and risks associated with the widespread use of drones. We carefully analyze anti-drone technology, dividing it into three crucial domains: detection, identification, and neutralization methods. This categorization enables us to delve into intricate technical details, highlighting the diverse techniques used to counter evolving drone threats. Additionally, we explore the legal and regulatory aspects of implementing anti-drone technology. Our research also envisions potential directions for advancing and evolving anti-drone tech to ensure its effectiveness in an ever-changing threat environment.

• 대한수의학회지
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• 제37권2호
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• pp.281-289
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• 1997

The study was designed to investigate the effects of progesterone and estrogen on the uterus of rats by immunohistochemical methods using Proliferating Cell Nuclear Antigen (PCNA) antibody. Eighteen female rats(Wistar), weighing initially about 300g, were ovariectomized. These rats were divided into four groups, progesterone-treated group, estrogen-treated group, estrogen+progesterone-treated group, and control group, progesterone-treated group was injected with 1mg of progesterone per rat per day for 2 days and estrogen-treated group with $20{\mu}g$ of $17{\beta}-estradiol$ for 3 days and estrogen+progesterone-treated group with $17{\beta}-estrdiol$ for 3 days and then with progesterone for 2 days as above. In gross findings, the uteri were markedly hypertrophied by estrogen treatment but were not affect in size by progesterone treatment. Immunohistochemical investigation was performed on the cell types with higher appearance of PCNA positive reaction cells in four groups. The groups with higher appearance of the stromal cells were ordered as estrogen-treated group, progesterone-treated group, estrogen+progesterone-treated group, and control group. The muscle cells were ordered as progesterone-treated group, estrogen-treated group, estrogen+progesterone-treated group, and control group. Positive reaction cells of the stromal cells were total 4.6 times higher than those of muscle cells. Therefore, the affect of the hypertrophy on the uterus by estrogen was larger than those of progesterone and affect on the uterus by stromal cells were larger than those of muscle cells. The group with more PCNA positive reaction cells of luminal epithelial cells were ordered as control group, progesterone-treated group, estrogen+progesterone-treated group, and estrogen-treated group, and glandular epithelial cells were ordered as estrogen+progesterone-treated group, progesterone-treated group, control group, and estrogen-treated group. It was suggested that estrogen and progesterone did not affect on the proliferating cells of luminal epithelial cells and affection of progesterone on the development of glandular epithelial cell was larger than that of estrogen.

• Journal of Chest Surgery
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• 제26권6호
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• pp.441-451
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• 1993

Protective effect of superoxide dismutase[SOD] and substrates on acute ischemic and reperfused myocardium was assessed by cardiac microdialysis. 30 Rabbits were divided into 4 groups; normal control group [group I, n=5], ischemic group [group II, n=5], SOD treated group [group III, n=10], and substrates treated group [group IV, n=10]. After a microdialysis apparatus was implanted in rabbit myocardium, coronary artery was occuluded for 5 minutes and reperfusion was performed for 30 minutes. Hemodynamic changes, CK-MB isoenzyme level and adenine ring compound level in effluent dialysates [equilibrated with interstitial fluid], and ultrastructural changes of myocardial cell were analysed. Systolic blood pressure at 10 and 30 minutes after reperfusion was higher in group III and IV than in group II [p<.05]. Also percent recovery of systolic blood pressure in group III [p<.01] and IV [p<.02] was higher than in group II. CK-MB isoenzyme level in effluent dialysates was peaked at 10 minutes after reperfusion, thereafter decreased in group II, III and IV. At 30 minutes after reperfusion, its level was lower in group III and IV than in group II[p<.05]. Adenine ring compound level in effluent dialysates increased till 10 minutes after reperfusion and progressively decreased. At 10 and 30 minutes after reperfusion, its level was lower in group III and IV than in group II without significance. Degree of myocardial damage was estimated by scoring of mitochondrial injury. Group I was within normal range and most severe injury was seen in group II. And the score of mitochondrial injury in group III and IV was lower than in group II. In conclusion, SOD and substrates[KMP solution] had protective effect on stunned myocardium. The microdialysis appratus was a good device for studying stunned myocardium, and cardiac microdialysis might be a unique technique for analysis of regional intramyocardial interstitial fluid.

• 디자인학연구
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• 제20권1호
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• pp.143-154
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• 2007

이미지에 대한 연구는 그동안 사회학, 심리학 및 마케팅 분야 등에서 행해져 왔으나 각 분야의 연구의도나 목적에 맞는 이미지 개념을 적용시켜 왔기 때문에 이미지에 대한 공통적인 개념을 규정하기는 쉽지 않다. 최근 감성공학에서 출발한 감성평가를 통해 제품의 이미지를 객관적으로 평가하려는 노력들이 시도되고 있다. 본 연구는 우리나라 중년 여성들의 라이프 스타일을 몇 가지 유형으로 분류한 후, 이에 따른 패션제품에 대한 이미지 선호도를 밝히고자 하였다. 연구 방법은 선행 자료의 분석을 통한 문헌연구와 설문지법을 통한 실증 연구를 병행하였다. 연구 대상은 만 35$\sim$59세 여성으로, 총 352부의 자료를 분석에 사용하였다. SPSS 11.0과 SAS for program 8.1 version을 이용하여 통계처리 하였다. 그 결과 패션 제품에 대한 이미지를 품위성, 대담성, 실용성, 여성성의 4개 인자로 하였다. 또 라이프스타일의 유형을 전통보수형, 소극정체형, 적극생활형, 외모중시형의 4개 집단으로 분류하였다. 분류된 라이프스타일 유형에 따라 선호하는 패션제품에 대한 이미지를 살펴 본 결과 전통보수형은 품위 있으며 실용적인 이미지의 패션 제품을 선호하였고, 소극정체형은 모든 패션 제품에 흥미를 보이지 않으나 여성스러움을 다소 추구하였다. 적극생활형은 대담한 이미지의 패션 제품을 선호하였으며, 외모과시형은 여성스러우며 다소 품위 있고 대담한 이미지를 선호하였다.