• International Journal of Naval Architecture and Ocean Engineering
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• 제9권1호
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• pp.1-10
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• 2017

Various offshore structures such as FPSO, FSO, Semi-submersible, TLP and Spar are operated to develop offshore oil and gas fields. Most of the offshore structures shall be operated over 20 years under the harsh environments at sites so that the offshore structures should be designed to endure the harsh environments. In this study, the effect of the impact load (so called slapping load) by the steep waves acting on the FPSO bow is investigated through the model test. For measurement of the impact pressures on the frontal area, a bow-shaped panel was fabricated, and installed the pressure sensors on the bow starboard side of the model FPSO. During the model test campaign, the impact load was investigated using the steep waves with $Hs/{\lambda}$ greater than 1/16 of the representative wave condition. Consequently, it is confirmed through the model test that the impact loads acting on the FPSO bow are significantly increased with the steep waves ($Hs/{\lambda}$ > 1/16) than the representative wave conditions of a maximum significant wave height and a pitch forcing period. Therefore, for safe design of North Sea FPSO, it is necessary to consider the steep waves in addition to the representative wave conditions and to be applied as proper structural load. Also, the effect of random seeds in irregular waves should be considered to build the safe FPSO.

• 한국식품영양학회지
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• 제31권3호
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• pp.425-434
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• 2018

Metabolic syndrome is a risk factor for cardiovascular and type 2 diabetes. This study was conducted to examine the relevance between nutrition intake, meal quality, and high-sensitivity C-reactive protein in Koreans with metabolic syndrome. The 2,536 subjects, aged 19~64, who participated in 2015 National Nutrition Survey were included in this study. The 24-hour recall method was employed to analyze nutrition intake and dietary quality. Subjects were grouped into either the non-metabolic syndrome group (n=1,938) or the metabolic syndrome group (n=598). Total males and females were divided into 3 groups according to the high-sensitivity C-reactive protein (hs-CRP) level to study its relationship to metabolic syndrome and its components, including odds ratio (OR) and confidence interval (CI). Results showed the homeostasis model assessment of insulin resistance (HOMA-IR) value was higher in the metabolic syndrome group (3.37) than non-metabolic syndrome group (1.57) (p<0.001). In the Index of Nutrition Quality, males in the non-metabolic syndrome group showed higher niacin (p<0.05) than males in metabolic syndrome group. Females in the non-metabolic syndrome group had higher vitamin $B_1$ (p<0.01), vitamin $B_2$ (p<0.001), niacin (p<0.05), calcium (p<0.001), and phosphate (p<0.01). Female in the high hs-CRP group showed high OR in blood glucose component (OR 2.488, 95% CI: 1.269~4.879) and metabolic syndrome risk (OR 2.856, 95% CI: 1.292~6.314). Females in the middle hs-CRP group had high triglycerides component (OR 2.956, 95% CI: 1.920~4.551), compared to the low hs-CRP group. The study showed females with higher hs-CRP had a higher risk of metabolic syndrome.

• Nutrition Research and Practice
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• 제10권3호
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• pp.328-335
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• 2016

BACKGROUND/OBJECTIVES: Vitamin D plays an important role in the etiology of gestational diabetes mellitus (GDM). This study evaluated the effect of vitamin D supplementation on metabolic indices and hs-C-reactive protein (CRP) levels in GDM patients. SUBJECTS/METHODS: The study was a randomized, placebo-controlled, double-blinded clinical trial. Seventy-six pregnant women with GDM and gestational age between 24-28 weeks were assigned to receive four oral treatments consisting of 50,000 IU of vitamin $D_3$ (n = 38) or placebo (n = 38) once every 2 weeks for 2 months. Fasting blood glucose (FG), insulin, HbA1c, 25-hydroxyvitamin D, lipid profile, hs-CRP, and homeostasis model assessment-insulin resistance (HOMA-IR) were measured before and after treatment. Independent and paired t-tests were used to determine intra- and intergroup differences, respectively. ANCOVA was used to assess the effects of vitamin D supplementation on biochemical parameters. RESULTS: Compared with the placebo group, in the vitamin D group, the serum level of 25-hydroxyvitamin D increased (19.15 vs. -0.40 ng/ml; P < 0.01) and that of FG (-4.72 vs. 5.27 mg/dl; P = 0.01) as well as HbA1c (-0.18% vs. 0.17%; P = 0.02) decreased. Improvements in the lipid profiles were observed in the vitamin D group, but without statistical significance. Significant increases in concentrations of hs-CRP, FG, HbA1c, total cholesterol, and LDL cholesterol were observed in the placebo group. No significant change in fasting insulin and HOMA-IR was observed in either group. CONCLUSIONS: In GDM patients, vitamin D supplementation improved FG and HbA1c but had no significant effects on lipid profile or hs-CRP.

• 보건행정학회지
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• 제31권2호
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• pp.158-172
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• 2021

Background: Metabolic syndrome has been known as a risk of cardiovascular disease. Meanwhile, high sensitivity C-reactive protein (hs-CRP) is used as a predictor of cardiovascular disease. In this paper, we aimed to investigate the association between hs-CRP and metabolic syndrome. Method: A total of 7,633 were chosen as the study population from the 7th Korea National Health and Nutrition Examination Survey dataset (2016-2017). Our dependent variable was whether an individual had metabolic syndrome or not, and the independent variable of interest was hs-CRP which was categorized into three groups. The chi-square tests and hierarchical logistic regression analyses reflecting survey characteristics were conducted. All analyses were stratified by gender. Results: According to the adjusted model with all covariates, compared to individuals having the low risk of hs-CRP, those having its average risk were more likely to have metabolic syndrome in men (odds ratio [OR], 1.41; 95% confidence interval [CI], 1.12-1.76) and women (OR, 1.69; 95% CI, 1.33-2.16). Individuals having the high risk was not significantly different in men; however, they were more likely to have metabolic syndrome in women (OR, 2.03; 95% CI, 1.28-3.23). Conclusion: In an upcoming aging society, it is important to reduce the risk of metabolic syndrome to improve population health. This study suggests that hs-CRP may be used as a marker of the risk of metabolic syndrome in a gender-specific way, thereby contributing to enhancing awareness of the risk of metabolic syndrome among the general public.

• Geomechanics and Engineering
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• 제14권5호
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• pp.479-489
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• 2018

In this paper, a comparative study of the effects of soil modelling on the interaction between tunnelling in soft soil and adjacent piled structure is presented. Several three-dimensional finite element analyses are performed to study the deformation of pile caps and piles as well as tunnel internal forces during the construction of an underground tunnel. The soil is modelled by two material models: the simple, yet approximate Mohr Coulomb (MC) yield criterion; and the complex, but reasonable hardening soil (HS) model with hyperbolic relation between stress and strain. For the former model, two different values of the soil stiffness modulus ($E_{50}$ or $E_{ur}$) as well as two profiles of stiffness variation with depth (constant and linearly increasing) were used in attempts to improve its prediction. As these four attempts did not succeed, a hybrid representation in which the hardening soil is used for soil located at the highly-strained zones while the Mohr Coulomb model is utilized elsewhere was investigated. This hybrid representation, which is a compromise between rigorous and simple solutions yielded results that compare well with those of the hardening soil model. The compared results include pile cap movements, pile deformation, and tunnel internal forces. Problem symmetry is utilized and, therefore, one symmetric half of the soil medium, the tunnel boring machine, the face pressure, the final tunnel lining, the pile caps, and the piles are modelled in several construction phases.

• Journal of Construction Engineering and Project Management
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• 제5권4호
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• pp.7-11
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• 2015

The luffing-tower crane (T/C) is a key facility used in the vertical and horizontal transportation of materials in a tall building construction. Locating the crane in an optimal position is an essential task in the initial stages of construction planning. This paper proposes a new optimization model to locate the luffing T/C in the optimal position to minimize the transportation time. A newly developed mathematical formula is suggested to calculate the transportation time of luffing T/C correctly. An optimization algorithm, the Harmony Search (HS) algorithm, was used and the results show that HS has high performance characteristics to solve the optimization problem in a short period of time. In a case study, the proposed model offered a better position for T/C than the previous heuristic approach.

• 수산경영론집
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• 제39권3호
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• pp.91-109
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• 2008

The worldwide proliferation of regional trade agreements combined with rising interests of 37countries has led to the emergence of a possible GSTP between each country. Although there are many obstacles to GSTP, its effect, if a realized, will go beyond trade related issues. This study was to specify and estimate a model of Korea-GSTP Ground in Korea that can be used to evaluate and improve management decisions. The development of the model relied on several submodels. On the trade negotiation side, a import demand function was estimated in order to account for the increasing amount of import. In terms of margin of preference(MOP)s, they were used to estimate values after decreasing tax based on scenarios I, II, and III. The results showed that the highest effects for increasing value and amount of import are a freezing crab(HS code 0306143000) and freezing hairtail(HS code 0303793000). This paper will be provide to help policy makers understand the Korea-GSTP Ground in the Korea fishery.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.420-424
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• 2015

The luffing-tower crane (T/C) is a key facility used in the vertical and horizontal transportation of materials in a tall building construction. Locating the crane in an optimal position is an essential task in the initial stages of construction planning. This paper proposes a new optimization model to locate the luffing T/C in the optimal position to minimize the transportation time. An optimization algorithm, the Harmony Search (HS) algorithm, was used and the results show that HS has high performance characteristics to solve the optimization problem in a short period of time. In a case study, the proposed model offered a better position for T/C than the previous heuristic approach.

• 해양환경안전학회지
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• 제21권5호
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• pp.583-590
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• 2015

우리나라 서남해역에서 추진될 해상풍력 발전 단지에서 생산된 전기와 기존의 전력망과의 계통연계를 위해서는 해저케이블 설치가 필수적인 요소이다. 특히 해저케이블 설치에 대한 경제성, 시공성 및 안정성 확보를 위해서는 해저케이블 경과지와 해저케이블 보호공법 설계가 이루어져야한다. 본 논문에서는 1979년부터 2002년까지 한국해양과학기술원에서 구축한 장기 파랑산출자료와 제3세대 파랑 모델인 SWAN(Simulating WAves Nearshore)을 이용하여 해상풍력단지가 조성될 해역에 대해 만조와 간조시 파랑시뮬레이션을 수행하여 해저케이블 경과지와 보호공법 설계를 위한 기초자료를 제공하고자 하였다. 연구결과, 서남해 해상풍력단지가 조성될 해역의 연평균 Hs는 1.03 m, Tz는 4.47s이고, 주파향은 북서(NW)와 남남서(SSW) 방향이다. NW에서 입사되는 조건(Hs: 7.0 m, Tp: 11.76s)에서 만조시 천해설계파랑 Hs의 분포는 약 4.0~5.0 m, 간조시에 약 2.0~3.0 m로 계산되었다. SSW에서 입사되는 조건(Hs: 5.84 m, Tp: 11.15s)에서 만조시 천해설계파랑 Hs의 분포는 약 3.5~4.5 m이고, 간조시에는 약 1.5~2.5 m로 계산되었다. 해저케이블 경과지 중 경도 UTM 249749~251349 구간 약 1.6 km에서는 NW로 입사되는 파랑의 영향이 크며, UTM 251549~267749 구간 약 16.2 km에서는 SSW로 입사되는 파랑의 영향이 지배적이다. 파랑집중 현상이 두드러지게 나타나는 해역은 위도와 하왕등도 사이 해역으로, 이 해역에서는 주변해역 보다 상대적으로 높은 파고를 나타내고 있다.

• 한국도로학회논문집
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• 제14권2호
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• pp.11-17
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• 2012

본 연구는 실험계획법(예: 반응표면계획법) 및 하모니 검색 알고리즘을 통하여 다양한 아스팔트 콘크리트 포장 구조체에 있어 피로균열의 공용성 인자인 인장변형률을 예측하는 모델을 개발하는 방법에 대한 연구이다. 인장변형률을 산정하기 위하여 한국건설기술연구소에서 개발한 유한요소 축대칭해석 프로그램인 KICTPAVE를 이용하여 아스팔트 층과 린콘크리트 층의 접속면에서 발생되는 변형률을 구하여 데이터베이스(D/B)화 하였다. 아스팔트 포장에서 입력변수인 층별 탄성계수 및 두께를 다양한 조건에서 KICTPAVE 프로그램을 수행하여 훈련용 D/B(Training Set)인 변형률의 값들을 구축한 후 반응표면계획법에 근거하여 회귀방정식을 정의하였으며 방정식에 필요한 계수값을 결정하기 위하여 하모니 검색 알고리즘을 이용하였다. 최종적으로 결정된 회귀방정식의 계수값들의 정확성을 검증하기 위해서 훈련용 D/B가 아닌 다른 조건의 입력변수를 이용하여 검증용 D/B(Testing Set)를 구축하고 이를 이용하여 개발된 모델을 검증하였다.