• 대한수학회지
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• 제57권2호
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• pp.429-450
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• 2020

We prove that wave operators for Schrödinger operators with multi-center local point interactions are scaling limits of the ones for Schrödinger operators with regular potentials. We simultaneously present a proof of the corresponding well known result for the resolvent which substantially simplifies the one by Albeverio et al.

• Journal of Computing Science and Engineering
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• 제3권4호
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• pp.218-237
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• 2009

Interactions are intrinsic part of what we do. We interact when we work, when we learn, when we visit a doctor, and when we play. With the advent of information and communications technology we can collect rich data (video, audio, and various transcripts including text chat) about such interactions. This opens an opportunity to monitor the dynamics of interactions and to get deeper insights of how they unfold and deliver this information to the interacting parties. This paper presents the design of a technology for visualising information about the dynamics of unfolding of interactions and presenting it in an ambient display on mobile devices. The purpose of this technology is the delivery of such information to the point of decision making.

• East Asian mathematical journal
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• 제34권3호
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• pp.317-330
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• 2018

We develop a mathematical model for the obesity dynamics to investigate the long term obesity trend with the consideration of psychological and social factors due to the increasing prevalence of obesity around the world. Many mathematical models for obesity dynamics adopted the modeling idea of infectious disease and treated overweight and obese people infectious and spreading obesity to normal weight. However, this modeling idea is not proper in obesity modeling because obesity is not an infectious disease. In fact, weight gain and loss are related to social interactions among different weight groups not only in the direction from overweight/obese to normal weight but also the other way around. Thus, we consider these aspects in our model and implement personal weight gain feature, a psychological factor such as body image dissatisfaction, and social interactions such as positive support on weight loss and negative criticism on weight status from various weight groups. We show that the equilibrium point with no normal weight population will be unstable and that an equilibrium point with positive normal weight population should have all other components positive. We conduct computer simulations on Korean demography data with our model and demonstrate the long term obesity trend of Korean male as an example of the use of our model.

• Elastomers and Composites
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• 제41권2호
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• pp.116-124
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• 2006

Poly(ethylene-co-15.3 mole% octene) ($PEO_{15}$) - 1-옥텐 2성분계 혼합물과 $PEO_{15}$와 (에틸렌 + 1-옥텐) 혼합용매로 이루어진 3성분계 혼합물의 상거동을 $160^{\circ}C$와 1,000 bar의 영역까지 측정하였다. $PEO_{15}$ - 에틸렌 - 1-옥텐 혼합물에서 에틸렌의 함량이 증가함에 따라 cloud-point 곡선이 측정되는 압력이 급격하게 높아졌다. 에틸렌 함량이 18 wt% 보다 낮을 경우, $PEO_{15}$ -에틸렌 - 1-옥텐 혼합물에서 bubble-point 곡선과 cloud-point 곡선이 모두 관측되었다. 에틸렌 함량이 증가함에 따라 $PEO_{15}$ - 에틸렌 - 1-옥텐 혼합물에서 bubble-point 곡선이 관측되는 온도범위는 좁아졌으며, $PEO_{15}$ - 에틸렌 - 1-옥텐 혼합물이 단일상으로 존재하는 온도-압력 영역이 현저히 감소하였다. 에틸렌 함량에 따라 단일상 영역이 감소하는 것은 $PEO_{15}$와 (에틸렌 + 1-옥텐) 혼합용매 사이에 작용하는 분산인력이 줄어들기 때문이다. 에틸렌을 36 wt% 보다 적게 함유한 $PEO_{15}$ - 에틸렌 - 1-옥텐 혼합물의 단일상 영역은 온도가 높아짐에 따라 감소하였다. 이와는 대조적으로 에틸렌을 50 wt% 보다 많게 함유한 $PEO_{15}$ - 에틸렌 - 1-옥텐 혼합물의 단일상 영역은 온도가 녹아짐에 따라 증가하였다. $PEO_{15}$ 용해도를 낮추는 혼합용매 사이의 극성인력과 $PEO_{15}$ 용해도를 높이는 혼합용매의 밀도는 온도가 낮아짐에 따라 증가한다. 에틸렌 함량이 50 wt% 보다 많을 경우, 혼합용매들의 극성인력 효과가 밀도 효과보다 커서 온도가 낮아짐에 따라 cloud-point 압력은 증가하였다. 에틸렌 함량이 50 wt% 보다 적을 경우, 혼합용매들의 극성인력 효과가 밀도 효과보다 작아서 온도가 낮아짐에 따라 cloud-point 압력은 감소하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 2차
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• pp.122-130
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• 2010

In recent days, the foundations of huge structures in general and mega foundations of grand bridges in particular are required in geotechnical engineering. However, previous design method based on virtual fixed point theory cannot adequately predict Pile-Bent structure‘s physical behavior. Therefore, this paper describes a new analysis and design of Pile-Bent structure for grand bridges. A detailed analysis was performed for column-pile interactions using FB-Pier program and Midas program. As a result, the behavior of a column-pile is estimated and highlighted. Moreover, based on this study, it is found that the minimum reinforcement ratio(=0.4%) is applicable for plastic behavior of columns.

• 대한가정학회지
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• 제42권6호
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• pp.123-136
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• 2004

The purposes of this study were to investigate the qualities of infant day-care centers and the caregivers' interactions with infants. Forty-six day-care centers from Seoul, Daejeon, and Daegu were enrolled in this study. Two kinds of methods were used for data collection; one was the Assessment Scale for Infant/Toddler Care Center developed by Choi and the other was the Qualitative Rating Scale for Caregiver used in the NICHD Early Child Care Project. Frequency, percentile, Crollbach's, one-way ANOVA, and Pearson's correlation were calculated for data analysis. Qualities on 5 factors of infant day-care centers were ranged from 3.44∼4.35, the highest with health managing and the lowest with support system in the Likert 5-point scales. Sensitivity, developmental stimulation and positive regard to child, which are the caregiver's positive interactions with infants were rated minimally or usually characteristic. In addition, intrusiveness, detachment, negative regard to child and flatness, which are negative interactions with infants were rated never or minimally characteristic. Finally, some suggestions for good quality and facilitation of infant care were made.

• 생물정신의학
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• 제7권1호
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• pp.3-13
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• 2000

There is nothing that is harmless ; the dose alone decides that something is no poison(Paracelsus, 1493-1541). So, in a point of view to maximize the therapeutic efficacy of drug therapy in a way that minimize the drug toxicity, the knowledges of the drug-ineractions as well as the pharmacokinetic and pharmacodynamic principles of every therapeutic drug used in the medical clinic cannot be emphasized too much. Many drug interactions can be predicted if the pharmacokinetic properties, pharmacodynamic mechanisms of action of the interacting drugs are known, and most adverse interactions can be avoided. In this paper, the clinical importance, classification, and general principles of clinical drug-interactions are presentated with a few explanatory examples.

• Elastomers and Composites
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• 제38권1호
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• pp.51-56
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• 2003

Cloud-point and bubble-point data to $170^{\circ}C$ and 50 bar are presented for four different solvents, normal pentane. n-hexane, n-heptane, and n-octane with poly(ethylene-co-42 wt% octene) ($PEO_{42}$) copolymer. The pressure-concentration isotherms measured for $PEO_{42}$ - normal pentane have maximums at around 5 wt% of the copolymer concentrations in the solution. $PEO_{42}$- normal pentane system exhibits LCST-type phase behavior at temperatures greater than $130^{\circ}C$. Below $120^{\circ}C$, bubble-point type transitions are observed. However, the binary mixtures for $PEO_{42}$ in n-hexane, n-heptane, and n-octane have only bubble-point type transitions at the pressure-temperature region investigated in this study. The single-phase region of PEO - alkane mixtures increases with the molecular size of alkane solvent due to the increasing dispersion interactions between PEO and the alkane.

• 대한화학회지
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• 제51권4호
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• pp.375-386
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• 2007

이 연구에서는 교사-모둠학생의 언어적 상호작용을 유형화하여 상호작용의 전체적인 형태를 확인 하고, 학생의 사고에 영향을 미치는 교사-모둠학생 상호작용의 특징을 살펴봄으로써 교사의 상호작용 개선에 기여하고자 하였다. 먼저 상호작용 유형은 문제해결과 관련된 행동과 기타의 두 범주로 구분하였고, 문제해결과 관련된 행동은 학생의 사고과정을 기초로 한 의견받기와 교사의 사고과정을 기초로 한 도움주기로 분류하였다. 의견받기는 동의와 질문, 교정, 반대가 포함되고, 도움주기는 정보와 힌트, 질문, 정리, 묻고 답하기로 세분화하였 다. 교사-모둠학생 상호작용은 대부분 교사의 질문과 학생의 답변으로 구성되었는데, 교사의 질문은 대체로 추론 형보다는 단순한 답을 요구하는 내용이 많았다. 또한 학생보다 교사의 사고과정에 더 많이 치우쳤으며, 정답을 제 시하는 한 두 학생과만 상호작용하는 경향이 있었다. 그 결과 교사의 도움주기 후에도 내용을 이해하지 못하는 학 생들이 종종 관찰되었다. 그러나 교사는 학생의 의견을 반복하여 동의를 표하거나 칭찬을 많이 하여 자신감을 심 어주고 있었으며, 학생의 모든 활동과 질문을 자유롭게 허용하여 누구나 편하게 의견을 제시할 수 있는 분위기를 만들고 있었다. 상호작용의 관찰로부터 학생의 사고에 영향을 미치는 교사의 상호작용 특성으로 동의나 격려의 표현, 생각을 유도하는 힌트의 제시, 학생의 의견을 기초로 한 상호작용, 허용적 분위기, 생각할 시간 제공, 학생 의 잘못된 의견 교정 등을 확인할 수 있었다. 이에 관련된 교육적 시사점을 논의하였다.

• 충청수학회지
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• 제13권1호
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• pp.119-130
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• 2000

We give alternative proof of the existence theorem for certain elliptic systems describing competing interactions with nonlinear di usion. The existence of positive solution depends on the sign of the principal eigenvalue of suitable operators of Schr$\ddot{o}$dinger type. If the sign of such operators are both positive, then system has a positive solution. The main tool employed is the fixed point index of compact operator on positive cones.