• 경영과학
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• 제31권3호
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• pp.113-130
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• 2014

Cooperative coevolutionary algorithm (CCEA) has proven to be a very powerful means of solving optimization problems through problem decomposition. CCEA implies the use of several populations, each population having the aim of finding a partial solution for a component of the considered problem. Populations evolve separately and they interact only when individuals are evaluated. Interactions are made to obtain complete solutions by combining partial solutions, or collaborators, from each of the populations. In this respect, we can think of various interaction modes. The goal of this research is to develop a CCEA for a supply chain network design (SCND) problem and identify which interaction mode gives the best performance for this problem. We present general design principle of CCEA for the SCND problem, which require several co-evolving populations. We classify these populations into two groups and classify the collaborator selection scheme into two types, the random-based one and the best fitness-based one. By combining both two groups of population and two types of collaborator selection schemes, we consider four possible interaction modes. We also consider two modes of updating populations, the sequential mode and the parallel mode. Therefore, by combining both four possible interaction modes and two modes of updating populations, we investigate seven possible solution algorithms. Experiments for each of these solution algorithms are conducted on a few test problems. The results show that the mode of the best fitness-based collaborator applied to both groups of populations combined with the sequential update mode outperforms the other modes for all the test problems.

• Asian Pacific Journal of Cancer Prevention
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• 제15권5호
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• pp.1993-1999
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• 2014

Background: This study aimed to explore the role of XRCC1 (Arg399Gln) and XPD (Lys751Gln) gene polymorphisms, lifestyle and environmental factors as well as their possible interactions in propensity to develop lung cancer in a population with high incidence from North East India. Materials and Methods: A total of 272 lung cancer cases and 544 controls were collected and XRCC1 (Arg399Gln) and XPD (Lys751Gln) genotypes were analyzed using a polymerase chain reaction based restriction fragment length polymorphism assay. Conditional multiple logistic regression analysis was used to calculate adjusted odds ratios and 95% confidence intervals after adjusting for confounding factors. Results: The combined Gln/Gln genotype of XRCC1 and XPD genes (OR=2.78, CI=1.05-7.38; p=0.040) was significantly associated with increased risk for lung cancer. Interaction of XRCC1Gln/Gln genotype with exposure of wood combustion (OR=2.56, CI=1.16-5.66; p=0.020), exposure of cooking oil fumes (OR=3.45, CI=1.39-8.58; p=0.008) and tobacco smoking (OR=2.54, CI=1.21-5.32; p=0.014) and interaction of XPD with betel quid chewing (OR=2.31, CI=1.23-4.32; p=0.009) and tobacco smoking (OR=2.13, CI=1.12-4.05; p=0.022) were found to be significantly associated with increased risk for lung cancer. Conclusions: Gln/Gln alleles of both XRCC1 and XPD genes appear to amplify the effects of household exposure, smoking and betel quid chewing on lung cancer risk in the study population.

• 대한환경공학회지
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• 제33권5호
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• pp.314-324
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• 2011

하수를 이용해서 배양된 조류는 바이오디젤 생산에 유용한 자원이다. 그러나 실제 하수에서 조류의 영양염류 신진대사와 하수 세균과의 상호작용에 관한 연구는 미흡하다. 본 연구에서는 하수로 배양되는 대표적 조류균주인 Ankistrodesmus gracilis SAG 278-2에 의한 하수 내 질소, 인 제거 거동을 평가하였고, 조류와 상호작용하는 하수 내의 세균 군집을 분석하였다. 하수 슬러지 세균 군집과 비교하였을 때, 조류-세균 복합 군집은 하수 내보다 높은 영양염류 제거를 보였다. 16S rRNA 유전자 분석 결과, 조류-세균 군집에서 조류가 성장함에 따라 Unclassified Alcaligenaceae 세균이 선택적으로 우점됨을 알 수 있었고, 조류에 의해서 선택적으로 우점화된 하수세균은 자연 수질 환경에서 조류와 공생적으로 상호작용 하는 것으로 알려진 Alcaligenes faecalis subsp. 5659-H와 계통학적으로 가까운 것으로 밝혀졌다. 본 연구의 결과, 하수 내의 높은 영양염류 제거를 보이는 조류-세균 복합 군집에서의 조류의 성장 및 신진대사가 특정 세균의 분포에 영향을 주는 것을 알 수 있었다.

• 한국임상약학회지
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• 제26권4호
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• pp.312-317
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• 2016

Objective: Midazolam is mainly metabolized by cytochrome P450 (CYP) 3A. Inhibition or induction of CYP3A can affect the pharmacological activity of midazolam. The aims of this study were to develop a population pharmacokinetic (PK) model and evaluate the effect of CYP3A-mediated interactions among ketoconazole, rifampicin, and midazolam. Methods: Three-treatment, three-period, crossover study was conducted in 24 healthy male subjects. Each subject received 1 mg midazolam (control), 1 mg midazolam after pretreatment with 400 mg ketoconazole once daily for 4 days (CYP3A inhibition phase), and 2.5 mg midazolam after pretreatment with 600 mg rifampicin once daily for 10 days (CYP3A induction phase). The population PK analysis was performed using a nonlinear mixed effect model ($NONMEM^{(R)}$ 7.2) based on plasma midazolam concentrations. The PK model was developed, and the first-order conditional estimation with interaction was applied for the model run. A three-compartment model with first-order elimination described the PK. The influence of ketoconazole and rifampicin, CYP3A5 genotype, and demographic characteristics on PK parameters was examined. Goodness-of-fit (GOF) diagnostics and visual predictive checks, as well as bootstrap were used to evaluate the adequacy of the model fit and predictions. Results: Twenty-four subjects contributed to 900 midazolam concentrations. The final parameter estimates (% relative standard error, RSE) were as follows; clearance (CL), 31.8 L/h (6.0%); inter-compartmental clearance (Q) 2, 36.4 L/h (9.7%); Q3, 7.37 L/h (12.0%), volume of distribution (V) 1, 70.7 L (3.6%), V2, 32.9 L (8.8%); and V3, 44.4 L (6.7%). The midazolam CL decreased and increased to 32.5 and 199.9% in the inhibition and induction phases, respectively, compared to that in control phase. Conclusion: A PK model for midazolam co-treatment with ketoconazole and rifampicin was developed using data of healthy volunteers, and the subject's CYP3A status influenced the midazolam PK parameters. Therefore, a population PK model with enzyme-mediated drug interactions may be useful for quantitatively predicting PK alterations.

• STI Policy Review
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• 제2권1호
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• pp.13-34
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• 2011

This paper investigates the interaction among the paradigm of Low-Carbon Society (LCS) and the megatrends in field of population, environment, geopolitics, and energy. The paradigm of LCS is regarded as a 'social will' trend, distinguished from other 'phenomenal' trends. The qualitative analysis shows that the megatrends and the LCS paradigm have positive/neutral/negative impacts on one another, while some impacts can be reversed to other types of impact with the conditions having ripened. In quantitative analysis, the correlation between the LCS paradigm and the economy is traced with our Integrated Assessment Model, looking into such response options as population control, increase in labor force participation, and productivity enhancement to maintain utility level despite the pursuit of LCS paradigm. The future challenges in national strategy and S&T policy are suggested, based on the interaction analyses.

• 한국지리정보학회지
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• 제17권4호
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• pp.167-178
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• 2014

수도권의 과도한 집중에 따른 부작용을 해소하고 국가 균형 발전 및 국가경제력 강화를 위하여 2012년 출범한 세종시는 대규모 택지개발이 급격한 개발속도로 이루어지면 주변지역 공간구조의 변화가 예상된다. 본 연구는 세종시 출범에 따른 인접지역의 공간구조 변화를 측정하기 위한 일환으로 공간적 상호작용 측면에서 접근하였다. 분석은 Accessibility 모델을 이용하여 미래 공간 상호작용을 위한 잠재력인 인구잠재력을 계산하고, 인구잠재력을 지표로 활용하여 공간패턴분석기법에 적용함으로써 세종시 건설 전후 인접지역들의 공간적 상호작용 결과를 정량적 정성적으로 해석하였다. 분석결과 1995년 이후 대상지역 인구잠재력의 영향범위는 지속적으로 감소하는 것으로 나타났으며, 2013년에는 천안시를 중심으로 인구가 집중하여 인구잠재력이 분산되는 것으로 나타났다. 세종시는 새로운 인구잠재력 지대로써 주변지역에 대한 구심점 역할을 수행하지 못하는 것으로 나타났지만 세종시의 입주가 얼마 지나지 않은 시점에서의 분석결과 때문으로 판단된다. 따라서 세종시의 계획인구 도달을 위한 노력과 함께 인구증가에 따른 요인들의 변화와 주변 도시들의 공간구조변화에 대한 지속적인 모니터링이 필요하다고 하겠다.

• 한국시스템다이내믹스연구
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• 제13권4호
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• pp.5-31
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• 2012

This paper aims at investigating the dynamics between aging population and local finance. In recent years, the aging rate has been accelerating the pace. The trend implies that Korea is moving towards the aging society, presumably, with unprecedented speed in the world. Aging society's biggest problems are centered around the explosive growth of the financial needs. In particular, these problems are apt to appear more seriously in local governments, as most of them are confronted with high level of aging population and poor financial bases. Firstly, it analyzes how the population structure in the local government impacts local finance, income and expenditure. Based upon in-depth literature reviews, this study examines variables related to aging population and local fiance. Secondly, it focuses on a series of positive and negative feedback loops which would reveal the essence of the mutual interaction structure between aging population and local governments' fiscal behaviors.

• 한국디지털건축인테리어학회논문집
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• 제12권1호
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• pp.71-79
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• 2012

This study aims at finding relationships between the competitiveness of cities and the size or distance of them, based on some premises; (1) the competitiveness can be measured on the interval-ratio level, that is, factor scores, (2) a hypothesis that the spatial interaction model is valid for the relationships can be generally accepted. Based on the general recognition a research hypothesis that the more is the population or the nearer is the distance from a central city the higher is the competitiveness score is constructed. According to the premises 5-factor scores and composite score are calculated by means of regression method, and the scores are regressed on cities' populations and distances from Seoul city. Using bootstrapping method for the tests of significance is effective due to small sample of 21 cities. Results of the analyses show that most aspects of the hypothesis should be rejected or adjusted. Scores on Health-welfare factor, public service factor, and commercial vitality factor have no relation to the cities' sizes or distances. But the results also find the facts that the strong (negative) relationships exist between (1) educational base factor score and population, (2) density factor score and distance. Although this study improves systematic and analytic understanding of spatial interaction patterns, the understanding should be invalid for the general context because it has used the data on 21 cities in the capital region at the time of 2009.

• Nutrition Research and Practice
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• 제13권6호
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• pp.498-508
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• 2019

BACKGROUND/OBJECTIVES: Lower circulating 25-hydroxyvitamin D [25(OH)D] levels are associated with a higher risk of hypertension (HTN); however, it remains unclear whether the relationship is causal. We aimed to evaluate the causal effects of circulating 25(OH)D levels on the prevalence of HTN in the Korean population using the Mendelian randomization (MR) approach. SUBJECTS/METHODS: Epidemiological data, serum 25(OH)D data, and genomic DNA biospecimens were obtained from 2,591 participants, a subset of the study population in the Korea National Health and Nutrition Survey 2011-2012. Five 25(OH)D-related single nucleotide polymorphisms (SNPs; DHCR7 rs12785878, CYP2R1 rs10741657, CYP2R1 rs12794714, CYP24A1 rs6013897, and GC rs2282679), identified a priori from genome-wide association studies, were used as instrument variables (IVs) for serum 25(OH)D levels. In the MR analysis, we performed IV analyses using the two-stage least squares method. RESULTS: In the observational analysis, circulating 25(OH)D levels were found to be inversely associated with the HTN prevalence in ordinary least squares models (odds ratio: 0.97, 95% confidence interval: 0.96, 0.99) after adjusting for the potential confounders. There were differences in the circulating 25(OH)D levels across genotypes of individual SNPs. In the MR analysis, using individual SNPs as IVs, 25(OH)D levels were not associated with the HTN prevalence. CONCLUSIONS: We found no association between genetically determined circulating 25(OH)D levels and HTN in Korean adults. Our results are listed owing to the relatively small sample size and possible weak instrument bias; therefore, further studies are needed to confirm these results.

• 한국동물학회:학술대회논문집
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• 한국동물학회 2003년도 한국생물과학협회 학술발표대회
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• pp.36-36
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• 2003

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