• Journal of Mechanical Science and Technology
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• 제20권12호
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• pp.2292-2314
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• 2006

Efficient numerical method is developed for the prediction of aerodynamic noise generation and propagation in low Mach number flows such as aeolian tone noise. The proposed numerical method is based on acoustic/viscous splitting techniques of which acoustic solvers use simplified linearised Euler equations, full linearised Euler equations and nonlinear perturbation equations as acoustic governing equations. All of acoustic equations are forced with immersed surface dipole model which is developed for the efficient computation of aerodynamic noise generation and propagation in low Mach number flows in which dipole source, originating from unsteady pressure fluctuation on a solid surface, is known to be more efficient than quadrupole sources. Multi-scale overset grid technique is also utilized to resolve the complex geometries. Initially, aeolian tone from single cylinder is considered to examine the effects that the immersed surface dipole models combined with the different acoustic governing equations have on the overall accuracy of the method. Then, the current numerical method is applied to the simulation of the aeolian tones from twin cylinders aligned perpendicularly to the mean flow and separated 3 diameters between their centers. In this configuration, symmetric vortices are shed from twin cylinders, which leads to the anti-phase of the lift dipoles and the in-phase of the drag dipoles. Due to these phase differences, the directivity of the fluctuating pressure from the lift dipoles shows the comparable magnitude with that from the drag dipoles at 10 diameters apart from the origin. However, the directivity at 100 diameters shows that the lift-dipole originated noise has larger magnitude than, but still comparable to, that of the drag-dipole one. Comparison of the numerical results with and without mean flow effects on the acoustic wave emphasizes the effects of the sheared background flows around the cylinders on the propagating acoustic waves, which is not generally considered by the classic acoustic analogy methods. Through the comparison of the results using the immersed surface dipole models with those using point sources, it is demonstrated that the current methods can allow for the complex interactions between the acoustic wave and the solid wall and the effects of the mean flow on the acoustic waves.

• 자원환경지질
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• 제48권3호
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• pp.213-219
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• 2015

해남 모이산 천열수 광산 주변의 열수변질작용에 의한 암석, 토양과 농작물간의 셀레늄의 상호작용을 규명하기 위하여, 모이산 인근의 토양과 농작물 시료를 채취 분석하였다. 토양시료는 6개의 산 토양과 6개의 밭 토양을 대상으로 수분함량, pH, ICP, XRD, XRF 분석을 통해 구성 광물과 원소함량을 분석하였으며, 농작물 시료는 토양과의 관계를 파악하기 위해 이 지역에서 재배된 양파와 대파를 대상으로 원소함량을 분석하였다. 토양에 대한 XRD 분석 결과, 주요 구성광물은 석영과 장석이며, 그 외 열수변질작용에 의해 일라이트, 녹니석과 적철석을 포함하고 있는 것으로 나타났다. 산 토양과 밭 토양의 pH는 각각 4.6~4.9와 5.2~6.7로 나타났는데, 산 토양에 비하여 밭 토양의 pH가 높게 나타난 것은 영농에 의한 비료시비가 원인으로 판단되었다. 원소함량 분석 결과, 비료의 영향이 크게 작용하는 밭 토양에서 산 토양에서는 검출되지 않았던 K(24.81~79.49 ppm), Ca(29.27~116.33 ppm) 등이 다량 함유한 것으로 나타났다. 이러한 경향은 작물에서도 나타나는데, 상대적으로 높은 농도의 K(116.89~169.79 ppm), Ca(20.18~32.29 ppm)가 농작물에 흡수되어 있는 것으로 분석되었다. 토양 시료에서의 Se 함량은 18.35~70.31 ppb의 범위로 분석되어 분석 시료간 유의미한 차이를 나타내지는 않았으나, 양파(119.48~179.50 ppb)와 대파(146.65 ppb)에서는 많은 양의 Se이 검출되었다. 이는 작물에 따라 각 원소에 대한 흡수율이 상이하여 농축도 역시 다르게 나타나는 것으로 판단되었다.

• 지능정보연구
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• 제13권3호
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• pp.47-61
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• 2007

기업 운영에서 SCM (Supply Chain Management)의 중요성이 인식되면서 공급, 생산, 분배 등의 기능들을 통합적으로 관리하는 새로운 접근법의 필요성이 커지고 있다. 이 접근법은 여러 다른 기능들의 의사결정 문제를 하나의 통합된 최적화 모델로 분석하는 방법이다. 특히 공급사슬의 통합적인 운영을 위해서는 이전의 확정적 방법론 보다는 보다 구매자와 공급자의 관계를 유연하게 통합해 줄 수 있는 방법론이 필요하다. SCM은 대규모 문제이고 또한 다양한 내외 요인에 의해 기존의 설정된 계획 내용이나 상황이 항시 동적으로 변경될 수 있기에, 이들 정보를 통합 계획에 반영될 수 있도록 하여야 한다. 본 연구에서는 SCM의 핵심이 되는 생산계획과 분배계획 문제들을 효율적으로 통합할 수 있는 유전 알고리즘 (Genetic Algorithm)을 제시하고, 유전 알고리즘을 기반으로 동적 SCM을 위한 멀티 에이전트 시스템을 구현한다. 한편 통합계획 문제에서 유전 알고리즘을 통해 100%에 근접하는 최적해를 구하였고, 통합계획으로 얻은 결과와 통합 계획을 하지 않은 경우의 결과 값에서 큰 차이를 확인 할 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권21호
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• pp.9347-9353
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• 2014

Background: Excision repair crossing-complementing group 2 (ERCC2), also called xeroderma pigmentosum complementary group D (XPD), plays a crucial role in the nucleotide excision repair (NER) pathway. Previous epidemiological studies have reported associations between ERCC2 polymorphisms and non-Hodgkin lymphoma (NHL) risk, but the results have remained controversial. Materials and Methods: We conducted this meta-analysis based on eligible case-control studies to investigate the role of two ERCC2 polymorphisms (Lys751Gln and Asp312Asn) in determining susceptibility to NHL. Ten case-control studies from several electronic databases were included in our study up to August 14, 2014. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed- or random-effects models to estimate the association strength. Results: The combined results based on all studies did not show any association between Lys751Gln/Asp312Asn polymorphisms and NHL risk for all genetic models. Stratified analyses by histological subtype and ethnicity did not indicate any significant association between Lys751Gln polymorphism and NHL risk. However, a significant reduced risk of NHL was found among population-based studies (Lys/Gln versus Lys/Lys: OR=0.87, 95% CI=0.77-0.99, P=0.037) but not hospital-based studies. As for Asp312Asn polymorphism, there was no evidence for the association between this polymorphism and the risk of NHL in all subgroup analyses. Conclusions: This meta-analysis suggests that there may be no association between Lys751Gln/Asp312Asn polymorphism and the risk of NHL and its two subtypes, whereas ERCC2 Lys751Gln heterozygote genotype may provide protective effects against the risk of NHL in population-based studies. Therefore, large-scale and well-designed studies are needed to clarify the effects of haplotypes, gene-gene, and gene-environment interactions on these polymorphisms and the risk of NHL and its different histological subtypes in an ethnicity specific population.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8579-8587
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• 2016

Background: The molecular mechanisms linking breast cancer progression and inflammation still remain obscure. The aim of the present study was to investigate the possible association of angiopoeitin like protein 4 (ANGPTL4) and its regulatory factor, hypoxia inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$), with the inflammatory markers nuclear factor kappa B/p65 (NF-${\kappa}B$/P65) and interleukin-1 beta (IL-$1{\beta}$) in order to evaluate their role in inflammation associated breast cancer progression. Materials and Methods: Angiopoietin-like protein 4 (ANGPTL4) mRNA expressions were evaluated using quantitative real time PCR and its protein expression by immunohistochemistry. DNA binding activity of NF-${\kappa}B$/P65 was evaluated by transcription factor binding immunoassay. Serum levels of ANGPTL4, HIF-$1{\alpha}$ and IL-$1{\beta}$ were immunoassayed. Tumor clinico-pathological features were investigated. Results: ANGPTL4 mRNA expressions and serum levels were significantly higher in high grade breast carcinoma ($1.47{\pm}0.31$ and $184.98{\pm}18.18$, respectively) compared to low grade carcinoma ($1.21{\pm}0.32$ and $171.76{\pm}7.58$, respectively) and controls ($0.70{\pm}0.02$ and $65.34{\pm}6.41$, respectively), (p<0.05). Also, ANGPTL4 high/moderate protein expression was positively correlated with tumor clinico-pathological features. In addition, serum levels of HIF-$1{\alpha}$ and IL-$1{\beta}$ as well as NF-${\kappa}B$/P65 DNA binding activity were significantly higher in high grade breast carcinoma ($148.54{\pm}14.20$, $0.79{\pm}0.03$ and $247.13{\pm}44.35$ respectively) than their values in low grade carcinoma ( $139.14{\pm}5.83$, $0.34{\pm}0.02$ and $184.23{\pm}37.75$, respectively) and controls ($33.95{\pm}3.11$, $0.11{\pm}0.02$ and $7.83{\pm}0.92$, respectively), (p<0.001). Conclusion: ANGPTL4 high serum levels and tissue expressions in advanced grade breast cancer, in addition to its positive correlation with tumor clinico-pathological features and HIF-$1{\alpha}$ could highlight its role as one of the signaling factors involved in breast cancer progression. Moreover, novel correlations were found between ANGPTL4 and the inflammatory markers, IL-$1{\beta}$ and NF-${\kappa}B$/p65, in breast cancer, which may emphasize the utility of these markers as potential tools for understanding interactions for axes of carcinogenesis and inflammation contributed for cancer progression. It is thus hoped that the findings reported here would assist in the development of new breast cancer management strategies that would promote patients' quality of life and ultimately improve clinical outcomes. However, large-scale studies are needed to verify these results.

• Child Health Nursing Research
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• 제6권2호
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• pp.132-143
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• 2000

The purpose of this correlational study was to find the correlation between the infant temperament, mother-infant interaction, and child-rearing environment. The subjects of this study were 37 dyads of healthy mothers and healthy infants. Data were collected from 15th of March to 3rd of September, 1999. Convenient sampling was done at Obstetric wards of one University hospital, and demographic data were collected before discharge. At one month and three month postpartum, we visited subject's home, and collected the data on the infant temperament, and also video taped the mother-infant interaction during feeding. In addition, child-rearing environment was checked by researcher according to HOME(Home Observation for Measurement of the Environment) at three months postpartum. Mother-infant interactions were rated according to the NCAST Feeding Scale later. Data were analyzed by window SPSS program, and correlations between the infant temperament, mother-infant interaction, and child-rearing environment were analyzed by Pearson's correlational coefficient. The results were as follows: 1. Infant temperament. 1) Among the subscales of infant temperament, mothers perceived cuddliness and amenability most positively at one month, and responsivity and amenability most positively at three months. 2) In subscale analysis of stability, amenability, responsivity, and persistence were stable with the time. 3) Significant relationships were found between the malleability and amenability, between the malleability and responsivity at one month, and also between the malleability and amenability, and between the malleability and cuddliness at three months. 2. Correlations of infant temperament and mother-infant interaction. 1) There was no significant relationship between the infant temperament and mother-infant interaction at one month. 2) There was a significant relationship between the infant temperament and mother-infant interaction at three months(r=.335, p<.05). In subscale analysis, there were significnt relationships between the total score of infant temperament and maternal sensitivity to infant's cues(r=.372, p<.05), and between the total score of infant temperament and maternal response to infant's distress (r=.331, p<.05). 3. Correlations of infant temperament and child-rearing environment. 1) There was no significant relationship between the total score of infant temperament at one month and total score of HOME at three months. In subscal analysis, the total score of infant temperament at one showed significant relationships with the organization of environment(r=.413, p<.05), and the emotional, verbal response at three months(r=.337, p<.05). 2) There was a significant relationship between the total score of infant temperament at three months and the total score of HOME at three months (r=.599, p<.01). In subscal analysis, the total score of infant temperament at three months showed significant relationships with the organization of environment(r=.410, p<.05), maternal involvement(r=.482, p,.01), and the emotional, verbal response(r=.695, p<.01) at three months. 4. Correlations of mother-infant interaction and child-rearing environment. There was a significant relationship between the maternal score of mother-infant interaction at one month and three months and the total score of HOME at three months (r=.474, p<.01; r=.452, p<.01). In conclusion, it was proved that infant temperament had significant relationships with mother-infant interaction and child-rearing environment, especially when the infants were getting older. This showed the possibility for changeability of infant teperament by the maternal factors.

• 한국콘텐츠학회논문지
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• 제12권5호
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• pp.541-552
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• 2012

이 연구는 온라인 학습커뮤니티 보조의 팀 학습(Online-Community Assisted Team Learning: OCATL)이 대학생의 '학업성취도'와 '공유된 정신모형(Shared Mental Model: SMM)'에 미치는 효과를 검증해내는데 있다. 각기 다른 지역에 소재하는 대학교의 대학생을 대상으로 2학기 동안 두 개의 연구가 실시되었다. 우선, 연구1에서는 OCATL을 실시하고 대학생의 학업성취도에 변화에 미치는 영향을 알아보기 위해 133명(남학생 80명, 여학생 53명)의 참가 대학생들의 OCATL 참여 전 후 학점에서의 평점평균(GPA)를 사용하여 비교하였다. OCATL 활동에는 '오리엔테이션', '협동학습 세미나', '온라인 학습커뮤니티 보조의 학기별 16시간 이상의 팀 학습', '최종보고서 제출'의 과정이 포함되었다. OCATL 활동 전후의 학점에서의 점수변화를 t검증을 통해 비교한 결과 통계적으로 유의한 차이가 나타났다(p<.05). 또한, 연구2에서는 OCATL을 실험집단(10팀)에 제공하고 통제집단(15팀)에는 온라인 학습 커뮤니티 보조를 제외한 팀학습을 하도록 하여 활동이 종료된 후에 SMM에서의 척도 점수를 비교하였다. 실험집단과 통제집단의 총 학생수는 74명이었다. SMM 측정은 Johnson(2011)이 개발한 SMM 척도의 단축문항지를 사용하였다. 분석결과, 팀 학습 이후 측정한 SMM 점수에서는 통계적으로 유의한 차이가 나타났다. 다변인분산분석(MANOVA) 결과, 온라인 학습 커뮤니티 환경을 지원된 팀학습 실험집단과 통제집단 간에 유의한 차이가 있었다. 또한 SMM의 하위 구성변인을 종속변인으로 하고 집단을 독립변인으로 한 단변랑 분산분석(ANOVA) 결과, '일반과제와 팀지식', '일반과제와 의사소통기술', '팀원과 과제에 대한 태도', '팀역동과 상호작용', '팀 자원과 활동환경', '팀만족도' 점수에서 실험처치 후 통계적으로 유의한 차이를 보였다($p$ <.05).

• 환경영향평가
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• 제29권2호
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• pp.144-155
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• 2020

본 연구에서는 다양한 생태계의 보전 및 생물다양성 보전과 증진을 통한 생태계의 지속가능한 이용을 위하여 우리나라 생태계 보호지역 확대를 위한 평가기법과 이의 정책적 활용 방향을 제시하였다. 이를 위하여 첫째, 생태계 보호지역 평가기법 활용 현황을 분석하였고, 둘째, 생태공학 기법을 기반으로 지역 규모의 생태계 보호지역 평가를 위한 개념 모형을 제시하였으며, 셋째, 이러한 분석 결과의 활용 방안을 제언하였다. 국외에서 보호지역 지정 시 다양한 분석 모형을 활용하고 있는 것과 달리, 우리나라의 경우 장기 생태계 모니터링 및 생태연구 자료가 부족하여 보호지역 지정 분석기법의 개발 및 적용이 미흡한 상태이다. 특히 미소 규모나 지역 규모보다는 국가 규모의 분석에 기반한 보호지역 지정이 주를 이루고 있어 지역 규모의 다양한 생태계가 반영되지 못하고 있다. 보호지역의 합리적인 지정과 효과적인 관리를 위해서는 다양한 인자들과 인자들 간의 상호작용을 고려한 지역 규모의 종합분석이 필요하며, 이를 위하여 본 연구에서는 생태공학 기법을 토대로 한 보호지역 분석의 개념 모형을 제시하였다. 본 연구에서 제시한 생태계 보호지역 분석은 다양한 생물 인자 및 비생물 인자, 그리고 이들의 상호작용 및 미래 환경변화를 고려한 각 지역 생태계의 특성을 반영하기 때문에 현재 우수한 생태계뿐만 아니라 앞으로 중요하게 보호해야 할 생태계를 보호지역으로 편입할 수 있는 근거를 제시하였다. 그러나 본 연구에서 제시한 분석 기법의 충분한 활용을 위해서는 각 지표항목과 지표항목에 속하는 인자들에 대한 개별 생태연구 자료 및 공간자료가 필요하다. 이러한 분석의 한계를 해결하기 위해서는 장기간의 생태자료와 종별 서식지 환경조건에 대한 연구 자료가 필요하며 서식지 모형, 생태모형, hybrid 모형 등 경관생태모형을 활용한 분석이 필요하다.

• 한국연초학회지
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• 제21권2호
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• pp.109-118
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• 1999

A model predicted describing the effect of cigarette making materials on the level of filter ventilation was developed and evaluated. The developed model was expressed in terms of a linear and quadratic relationship which was validated with experimental measurements for different porosity of plug wrap and tipping paper, unencapsulated pressure drop of filter plug and cigarette column and vent position. Forty-six experimental frequencies were determined as a result of using three levels with five factors Box-Behnken design and analyzed by the multiple regression analysis with backward stepwise in STATISTICA/PC under restricted conditions. The four factors, except filter pressure drop variable, were statistically significant at the level of 0.05 but most of all linear by linear interactions were comparatively lower significant. By the analysis of linear and quadratic regression coefficient, filter ventilation of the cigarette was affected by porosity of plugwrap (5.87, -4.25), porosity of tip paper (5.68, -1.00), vent position (-3.87, 3.08), tobacco column pressure drop (2.56, 0.66), and filter pressure drop (1.50, 0.58) in the decreasing order. It should be emphasized that the major conclusion of this study was not that any particular parameter was linear or quadratic on any limit scale, but that there were highly significant relationships among factors involving linear, quadratic and their interaction and perhaps even linearity between and within factors. While, there is also quite strong evidence that vent position from mouth end and cigarette making materials are reverse relationship on this experimental model. On the basis of the result, it can be concluded that the porosity of the plug wrap and tipping paper has a marked effect on degree of filter ventilation rate. The F-value of plug wrap and tipping paper porosity among five factors were 39.2 and 36.8 respectively with P-value of 0.000 indicating higher significant for both factors. According to the analysis of variance, the model fitted for filter ventilation was significant at 5% confidence level and the coefficient of determination ($R^2$=0.84) was the proportion to variability in the data well fitted for by the model.

• 여성건강간호학회지
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• 제1권1호
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• pp.5-27
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• 1995

One of the important tasks for new parents, especially mothers, is to establish warm, mutually affirming interpersonal relationships with the new baby in the family, with the purpose of promoting the health development of the child and the well-being of the whole family. Nurses assess the quality of the behavioral characteristics of the maternal-infant interaction. The purpose of this longitudinal descriptive correlational study is to investigate the changes of the mother - infant interactions from postpartum 1 day to postpartum 8weeks of the transition to parenthood. The aim was to contribute to the development of theoretical under standing on which to base care toward promoting the quality of maternal - infant interaction. Data were collect ed directly by the investigator and at rained from Jul, 1, 1990 to Jun 8, 1991, Subjects were a random sample of 44 mothers, 44 who had a normal delivery (but with out other perinatal complications) at four general hospitals in Seoul. Instruments used were the Stainton Parent-infant Interaction Scale (1981). The first observations were made in the delivery room, followed by day 1, day 2, day 3 and 2 weeks, 4 weeks, 6 weeks and 8 weeks after, birth, for a total of 8 contacts. Observations in the hospital were made during the hour prior to scheduled feedings. The infant was placed beside the mother. Later contacts were made at home. Data analysis was don by computer using as SPSS program and included, Paired t-test, t-test and Pearson Correlation coefficient ; the results were as follows. 1. The daily maternal-infant interaction score for the initial contact ofter birth to 8 weeks postpartum had the lowest average score 5.21 and the highest 8.02(in a range of 0-10). This subject group of mothers needed Extra nursing supporting to promote their maternal-infant interaction. 2. The daily scores for the maternal-infant interaction tended to rise, showing a gradual improvement over the period of eight weeks. However, there were significantly different increases in maternal-infant interaction only from the first to second day (p=0.000) and from the fourth to sixth weeks ofter birth.(p=0.000) 3. When the seven items of maternal-infant interaction were evaluated items of maternal-infant inter action were evaluated separately, "Care taking for the baby" had the highest average score, 1.60(in a range of 0-2) and "Speaks to baby" the lowest, 0.8. All items, suggested the subjects' need of nursing intervention to promote maternal-infant interaction 4. There were positive correlations between certain general characteristics, namely, both a higher economic status (p=0.027) and breast feeding (p=0.021) and maternal-infant interaction.