• 한국식품영양과학회지
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• 제34권4호
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• pp.466-475
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• 2005

본 연구에서는 인공 사육 모델 시스템과 인공 쥐용 분유를 이용하여 출생 직후 12시간 이내에 엄마 쥐들로부터 신생 쥐를 분리하여 n-3 지방산 결핍분유와 n-3 지방산 적절분유로 3주 동안 사육한 후(이유기) 각각 장기들을 취하고 또한 성숙 쥐(15 wks)의 뇌, 망막, 간을 취하여 뇌 성장 발달 과정 동안 n-3지방산 결핍이 이들 장기들의 지방산조성 변화에 미치는 영향을 알아보고자 한다. 이유기와 성숙기 쥐의 뇌 지방산 조성은 n-3 지방산 적절군과 대조군과 비교했을 때, n-3지방산 결핍군의 경우 n-6지방산의 함량은 높았으나 (p<0.05), 총 monounsaturated 지방산과 총 n-3 지방산의 함량은 낮았고(p<0.05), 총 saturated 지방산의 경우는 변화가 없었다. 기대했듯이 뇌 DHA의 경우 n-3 지방산 결핍군은 n-3 지방산 적절군과 대조군에 비해 이유기 때 $50\%$, 성숙기에는 $70\%$까지 감소하였고 반면 n-6 계열인 DPAn-6의 함량은 상당히 증가하였음을 살펴볼 수가 있었다. 이유기의 망막의 총 saturated 지방산과 총 monounsaturated 지방산에는 식이군 사이에 변화가 없었고 22:4n-6, DPAn-6와 총 n-6 지방산의 함량은 n-3 지방산 결핍군에서 n-3 지방산 적절군과 대조군에 비해 증가하였으나(p<0.05), 22:5n-3, DHA와 총 n-3 지방산의 함량은 상당히 감소하였음을 관찰할 수가 있었다(p<0.05). 성숙 쥐 망막의 지방산조성의 경우 20:4n-6, 22:4n-6, 22:5n-6와 총 n-6 지방산의 함량은 n-3 지방산 결핍군에서 n-3 지방산 적절군과 대조군에 비해 증가하였으나(p<0.05), 22:5n-3, DHA와 총 n-3 지방산의 함량은 상당히 감소하였다(p<0.05). 특히 n-3 결핍군의 망막 DHA는 이유기 때 $57\%$ 감소에서 성숙기에 $63\%$까지 감소하였다. (p<0.05). 간의 경우, 이유기의 n-3 지방산 결핍군의 DHA는 $65\%$ 감소한 반면 간의 DPAn-6는 $59\%$ 증가하였다. 흥미로운 것은 이유기의 간 지방산 조성과는 대조적으로 성숙기의 n-3 지방산 결핍군의 18:2n-6, 20:3n-6, 20:4n-6와 22:4n-6 지방산 함량이 현저히 감소된 것과는 달리 DPAn-6의 함량이 n-3 지방산 적절군보다 $143\%$까지 증가되었음 관찰할 수 가 있었다(p<0.05). 이상의 장기들의 n-3지방산 결핍군은 이유기와 성숙기에서 DPAn-6/DHA비와 n-6/n-3비 또한 n-3 지방산 적절군과 대조군에 비해 컸으나(p<0.05) DPAn-6와 DHA의 합에는 변화가 없었다. 따라서 뇌 성숙 발달 과정동안 n-3 지방산 결핍은 뇌의 DHA의 결핍을 초래하고 이러한 비정상적인 조건에서 DPAn-6의 증가를 유발하였으며 이러한 지방산 조성의 변화와 공간과 후각에 기초를 하는 기억 학습 능력 저하의 관련성에 대해서는 앞으로 연구가 진행되어져야 할 것으로 사료되어진다.

• 대한방사선기술학회지:방사선기술과학
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• 제40권1호
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• pp.93-99
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• 2017

Monte Carlo 시뮬레이션을 이용하여 MV X, ${\gamma}$선에서의 선량증가 효과를 평가하였다. MCNPX code를 이용하여 ICRU 평판형(Slab) 모의피폭체를 전산모사하였으며, 입사 광자의 에너지, 선량증가 물질의 종류 및 농도에 따른 영향을 분석하였다. 선량증가 물질은 금(aurum), 가돌리늄(gadolinium), 요오드(iodine), 산화철(iron oxide)에 대해 비교 평가하였으며, 입사에너지는 선형가속기에서 발생된 4, 6, 10, 15 MV X선의 스펙트럼과 Co 60의 ${\gamma}$선원을 사용하였다. 모의피폭체 내에 7, 18, 30 mg/g 농도의 물질을 삽입하였으며, 선량증가 효과의 정량적 평가를 위해 선량증가비를 산출하였다. X선의 입사에너지가 낮을수록, 선량증가 물질의 농도가 높을수록 높은 선량증가비를 나타내었으며, 최대 선량증가비는 금 1.079, 가돌리늄 1.062, 요오드 1.049, 산화철 1.035를 보여 금, 가돌리늄, 요오드, 산화철 입자 순으로 높은 선량증가 효과를 보였다. 이러한 결과는 In-vivo, vitro 연구의 기초자료로 활용할 수 있을 것으로 사료된다.

• International Journal of Control, Automation, and Systems
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• 제1권2호
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• pp.178-183
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• 2003

This work is a modified version of an earlier work that was based on ellipsoidal type feasible sets. Unlike the earlier work, polyhedral types of invariant and feasible sets are adopted to deal with input constraints. The use of polyhedral sets enables the formulation of on-line algorithm in terms of QP (Quadratic Programming), which can be solved more efficiently than semi-def algorithms. A simple numerical example shows that the proposed method yields larger stabilizable sets with greater bounds on disturbances than is the case in the earlier approach.

• Journal of applied mathematics & informatics
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• 제5권3호
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• pp.669-690
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• 1998

In this paper we develop a new theory of adjoint and symmetric method in the class of general implicit one-step fixed-stepsize methods. These methods arise from simple and natral def-initions of the concepts of symmetry and adjointness that provide a fruitful basis for analysis. We prove a number of theorems for meth-ods having these properties and show in particular that only the symmetric methods possess a quadratic asymptotic expansion of the global error. In addition we give a very simple test to identify the symmetric methods in practice.

• East Asian mathematical journal
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• 제18권2호
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• pp.205-209
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• 2002

In the paper the following propositions are proved. 1) If ($Q,{\cdot},e$) is a B-algebra, then there exists a group($Q,A,^{-1}$, 1) such that the following equalities hold e=1 and ${\cdot}=^{-1}A$, where $^{-1}A(x,y)=z{\Longleftrightarrow^{def}}A(z,y)=x$; and 2) If ($Q,A,^{-1}$, e) is a group, then ($Q,^{-1}A$, e) is a B-algebra.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.219-220
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• 2007

• 산업융합연구
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• 제1권1호
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• pp.115-126
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• 2003

In order to examine the determinants of new product success, winning products are analyzed with a focus on merchantability. The specific dimensions of product advantage have not been studied as yet. As results of the analysis, the determinants are classified into function, aesthetics, economy, safety, usability, reliability, brand image, assurance, distribution channel, advertisement, DEF(design for the environment). This study augmented the data set through questionnaire survey to marketing professor in University. The results of this study would be a cue to the future direction of new product development and to management of exist product.

• 한국초등과학교육학회지:초등과학교육
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• 제34권1호
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• pp.109-122
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• 2015

In National Curriculum of Science revised in 2007, free inquiry was newly introduced to increase student's interest in science and to foster creativity by having students make their own curiosity questions and find answers by themselves. The purpose of this study is to analyze elementary school students' perceptions on free science inquiry activities applying a brain-based evolutionary approach. For this study, 106 the fifth grade students participated, and then completed a questionnaire on free inquiry activities according to a brain-based evolutionary science teaching and learning principles. The students performed a series of steps of the Diversifying, Estimating-Evaluating-Executing, and Furthering activities in each of Affective, Behavioral, and Cognitive domains (ABC-DEF approach) and constructed their own free inquiry diary, then the observations by the researcher and interviews with the students were analyzed both quantitatively and qualitatively. The major results of the study were as follows: First, the majority of the students perceived the each domain and step positively although a few of them perceived negatively. The reasons perceived as negatively were categorized into two; preference dimension of like or dislike and ability dimension of metacognitive or self-reflective capacity. Also, they perceived the free inquiry experience in the form of ABC-DEF as helpful to understand the nature of scientists' scientific activities. Based on these findings, implications for supporting authentic inquiry in school science are discussed.

• 대한소아치과학회지
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• 제1권1호
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• pp.57-61
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• 1974

The Study reported here was designed to analyze the prevalence of Dental Caries in the primary teeth of monozygote twins, and to ascertain and compare the intrapair differences with the intrapair differences in control pairs. The prevalence of dental caries in the primary teeth of 40 pairs of presumably monozygote twins, based on phenotypic analysis, was studied. The age range was from 3 to12 years. The control group consisted of pairs that included a twin chosen at random and an unrelated child of the same sex and age, so that for each pair of twins there was a corresponding control pair. The clinical examination was carried out by an operator using an oral mirror and sharp explorers, and with good lighting. 40 pairs of twins were examined with a total of 4,950 primary tooth surfaces (990 primary teeth) and 40 control pairs with a total of 4,935 primary tooth surfaces (987 primary teeth). Five surfaces were considered for each tooth. After the def individual index was determined, the ratio between this index and the number of examined surfaces was established in each case, the cer (Caries experience rate) index. The def and cer averages were determined for the subjects and the controls. All intrapair differences in twin and control groups were compared following the paired sampling method. The following conclusions were made: 1. Intrapair differences in the control group were significantly greater than in twins, when defs, ds, es, fs, and cer were compared. 2. The genotype appeared to be a determining factor in dental caries susceptibility or resistance, although the environment played an important role as well. 3. Intrapair differences in American children were significantly greater than in Korean when defs, es, fs, and cer were compared, but ds was equal.

• 대한수학회지
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• 제48권6호
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• pp.1171-1187
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• 2011

Silverman [14] proved a height inequality for a jointly regular family of rational maps and the author [10] improved it for a jointly regular pair. In this paper, we provide the same improvement for a jointly regular family: let h : ${\mathbb{P}}_{\mathbb{Q}}^n{\rightarrow}{{\mathbb{R}}$ be the logarithmic absolute height on the projective space, let r(f) be the D-ratio of a rational map f which is de ned in [10] and let {$f_1,{\ldots},f_k|f_l:\mathbb{A}^n{\rightarrow}\mathbb{A}^n$} bbe finite set of polynomial maps which is defined over a number field K. If the intersection of the indeterminacy loci of $f_1,{\ldots},f_k$ is empty, then there is a constant C such that $ \sum\limits_{l=1}^k\frac{1}{def\;f_\iota}h(f_\iota(P))>(1+\frac{1}{r})f(P)-C$ for all $P{\in}\mathbb{A}^n$ where r= $max_{\iota=1},{\ldots},k(r(f_l))$.