• 대한토목학회논문집
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• 제36권4호
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• pp.715-722
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• 2016

국내 대부분의 노선은 자갈도상궤도로 이루어져 있어, 지속적인 유지보수가 요구되고 있다. 따라서, 보다 효과적인 요지보수를 통해 비용 절감을 위해서는 예방보수를 통한 유지보수의 최적화가 필요하다. 여기에는 도상자갈층의 침하 진전모델의 확보가 필수적이다. 그러나, 자갈도상재료는 입자가 큰 조립재료로써 일반 지반재료와는 다른 거동을 보인다. 따라서, 본 연구에서는 자갈재료의 거동에 대한 이해와 침하진전모델의 합리적인 개발을 위해 개별요소해석을 수행하였으며, 입자 형상, 공극률, 하중조합 및 빈도에 따른 침하거동을 비교 분석하였다.

• Journal of Microbiology and Biotechnology
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• 제27권8호
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• pp.1457-1460
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• 2017

Seven flavonoids were isolated from Spatholobus suberectus via repetitive column chromatography and high-performance liquid chromatography. The chemical structures of these compounds were identified by spectroscopic analysis and comparison with values reported in the literature. Among the flavonoids tested, 7-hydroxy-6-methoxyflavanone (1) and formononetin (4) exhibited strong inhibitory activity against Streptococcus mutans SrtA, with $IC_{50}$ values of 46.1 and $41.8{\mu}M$, respectively, but did not affect cell viability. The onset and magnitude of inhibition of saliva-induced aggregation in S. mutans treated with compounds 1 and 4 were comparable to the behavior of a srtA-deletion mutant without treatment.

• International Journal of Air-Conditioning and Refrigeration
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• 제9권1호
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• pp.29-38
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• 2001

In this paper, the defrosting characteristics of a PTC heating sheet is investigated by means of a defrosting heat source for the fin-tube heat exchanger in a refrigerator The defrosting characteristics of the PTC heating sheet are examined and compared with those of a conventional electric heater experimentally. It is found that the characteristics of the water draining rate with the defrosting time show a smoothly oscillating pattern when the PTC heating sheet Is used, and the drained water is completely melted. The defrosting efficiency of the PTC heating sheet is found to be about 75%, which is about 25% higher than that of the electric heater. Also, the reduction of the defrosting time and the increment of the defrosting efficiency may be obtained by improving the arrangement of the heating elements of the healing sheet. It is shown that the defrosting time of the PTC heating sheet increases linearly with the amount of frost, whereas the defrosting efficiency is nearly constant. When applying the PTC heating sheet to the refrigerating system, one should notice the fact that the defrosting performance of the PTC heating sheet may be degraded due to the repetitive operations.

• 기본간호학회지
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• 제16권2호
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• pp.223-231
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• 2009

Purpose: The purpose of this study was to identify the effects on cognitive function, mood, problematic behaviors and response to interaction with robot pet by elderly people with dementia. Method: A methodological triangulation design with quantitative and qualitative methods was used. The participants were 9 elderly people with dementia. The intervention was conducted twice a week for 4 weeks, Qualitative data were collected by interviews and video-taping for analysis of the responses of participants, Results: 1) Cognitive function, mood and problematic behaviors did not show any significantly differences after the program. 2) Analysis of the responses showed increases in verbal communication and positive action. Conclusion: The robot pet program had positive effects such as increasing communication and interaction. Therefore, this program could be considered as an effective program for emotional support for elderly people with dementia. However further repetitive study is need to validate the result.

• 아동학회지
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• 제35권5호
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• pp.63-82
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• 2014

The purpose of this study is to elucidate how two young children understand force in rough-and-tumble play. For this purpose, a form of microanalysis(Forman, 2006) was used. They regarded black as the strongest color due to their daily experiences. They assumed that a structure made of black Lego-color-bricks would be strongest and made an experiment of beating it against blocks of other colors. Such repetitive behavior ultimately led them to realize that color had no correlation with strength. They also understood mechanical energy by which a boy's pushing power moves against an object. They tried to strike a bigger or protruding structure and understood that parts might be broken more easily by striking. This experience enabled the boys to realize the principle of resistance. That is to say, in the process of rough-and-tumble play, their misconceptions were gradually removed and they obtained scientific knowledge, including understanding of mechanical energy and the principle of resistance. This study found that two young children constructed knowledge together through the process of tool making and in contending for victory in rough-and-tumble play.

• 성인간호학회지
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• 제17권5호
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• pp.743-752
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• 2005

Purpose: The purposes of this study were to identify the level of total symptom distress, uncertainty, depression and ways of coping in women with endometriosis based on Mishel's model of Uncertainty in Chronic illness, and to exam the relationships among symptom distress, depression and ways of coping and the mediating effect of ways of coping between uncertainty and depression. Method: The research was used for correlational research design and data were collected with 123 women with endometriosis who live in a local area by convenience sampling. Results: The finding showed that the levels of symptom distress and uncertainty were moderate and the depression was above the middle level. There were positive relationships among symptom distress, uncertainty and depression but a negative relationship between problem focused coping and depression. The significant predictors for depression were symptom distress, uncertainty, and problem focused coping with 40% of explained variance. Problem focused coping showed mediating effect between uncertainty and depression. Conclusion: Therefore, nursing intervention for the strategy of increasing problem focused coping as well as lowering uncertainty and depression is recommended. Further study is needed to conduct a repetitive study with randomized nationwide population and to evaluate the theory with different outcomes for adaptation versus maladaptation.

• International Journal of Aeronautical and Space Sciences
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• 제11권4호
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• pp.345-350
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• 2010

The repetitive vibrating action of an aerodynamic load causes an external fuel tank's horizontal fin to experience a shorter life cycle than its originally predicted one. Store separation analysis is needed to redesign the fin of an external fuel tank. In this research, free-drop tests were conducted using 15% scaled models in a subsonic wind tunnel in order to analyze the store separation characteristics of an external fuel tank. The store separation trajectory based on grid tests was also obtained to verify the results of the free-drop tests. The results acquired from the free-drop tests correlated well with the grid tests in regards to the trajectories and behavior of the stores separated from the aircraft. This agreement was especially noted in the early stages of the store separation.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제31권3호
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• pp.131-145
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• 2020

The microbiota-gut-brain axis, which refers to the bidirectional communication pathway between gut bacteria and the central nervous system, has a profound effect on important brain processes, from the synthesis of neurotransmitters to the modulation of complex behaviors such as sociability and anxiety. Previous studies have revealed that the gut microbiota is potentially related to not only gastrointestinal disturbances, but also social impairment and repetitive behavior-core symptoms of autism spectrum disorder (ASD). Although studies have been conducted to characterize the microbial composition in patients with ASD, the results are heterogeneous. Nevertheless, it is clear that there is a difference in the composition of the gut microbiota between ASD and typically developed individuals, and animal studies have repeatedly suggested that the gut microbiota plays an important role in ASD pathophysiology. This possibility is supported by abnormalities in metabolites produced by the gut microbiota and the association between altered immune responses and the gut microbiota observed in ASD patients. Based on these findings, various attempts have been made to use the microbiota in ASD treatment. The results reported to date suggest that microbiota-based therapies may be effective for ASD, but largescale, well-designed studies are needed to confirm this.

• 정보처리학회논문지D
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• 제17D권2호
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• pp.111-118
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• 2010

본 논문에서는 Simulink로 모델 검사를 위한 향상된 기능을 가진 디버거의 구현에 대해 기술한다. Simulink에서 기본적으로 제공되는 디버그 기능은 복잡한 시나리오나 복잡한 모델을 검사할 때 단순 반복적인 작업이 다수 요구되었다. 이를 개선하기 위해서 본 연구에서는 임의의 시나리오에 따른 시뮬레이션 결과와 예상한 결과를 확인할 수 있는 기능, 원하는 시점에서 시스템의 변화를 확인하는 기능, 임의의 혹은 전체 시나리오에 대한 시스템의 Coverage Report 기능 등이 구현된 Simulink 디버거에 대해 소개하고 구현에 대한 이슈를 기술한다. 이 프로그램을 Matlab에서 제공하는 자판기 모델에 적용해서 그 유용성을 확인했다.

• 한국건설관리학회논문집
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• 제8권3호
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• pp.134-141
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• 2007

건축공사에서 종사하는 기능인력의 근골격계질환은 직업병으로서 매우 심각하다 이와 같은 질환은 반복되거나 불편한 작업자세 및 방법에 기인한 것으로서 본 연구의 목적은 건축공사의 대표직종인 목공과 철근공을 대상으로 수작업 부하를 측정하여 부하정도를 분석하고자 한다. 또한 부하정도를 평가하기 위하여 건강한 대학원생을 대상으로 동일한 작업자세에서의 부하정도를 측정하는 실험을 실시한다. 본 연구의 결과는 근골격계부담작업의 개선을 위한 작업형태 및 작업자세의 개선, 사용하는 수공구의 인간공학적 기술 개선을 위한 매우 소중한 기초자료로 활용될 수 있다.