• Journal of Nutrition and Health
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• v.47 no.3
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• pp.186-192
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• 2014

Purpose: The prevalence of metabolic syndrome has increased in both the adult population and in adolescents. However, few studies have been conducted for adolescents. The aim of this study was to examine the association of metabolic syndrome and its risk factors with high carbohydrate diet and high fat diet using data from the Korea National Health and Nutrition Examination Survey (1998-2009). Methods: Using the Acceptable Macronutrient Distribution Range for Korean Dietary Reference Intakes, subjects whose energy intake from carbohydrate was greater than 70% and from fat was less than 15% were classified as the 'High-carbohydrate & low-fat diet (HCLF)' group and subjects whose energy intake from carbohydrate was less than 60% and from fat was 25% or more were classified as the 'Low-carbohydrate & high-fat Diet (LCHF)' group. Among 5,931 eligible subjects, HCLF included 853 subjects and LCHF included 1,084 subjects. Results: The mean age in both groups was 14 years and significant difference in age, BMI, sex, physical activity, and household income was observed between the HCLF and LCHF groups. Regarding the energy intake compared to Estimated Energy Requirement, the HCLF group met 79.0% and the LCHF group met 100.3%. Regarding nutrient intake per 1,000 kcal, carbohydrate, iron, potassium, and vitamin C intake in the HCLF group were significantly higher, but protein, fat, calcium, phosphorus, vitamin A, thiamin, riboflavin, and niacin intakes were significantly lower in the HCLF group compared to the LCHF group. After adjusting for age, sex, BMI, study year, household income, physical activity, and energy intake, the serum triglycerides level and systolic blood pressure were slightly higher, while the serum HDL-cholesterol level was significantly lower in HCLF than LCHF. The odds ratio of metabolic syndrome did not differ significantly between HCLF and LCHF. Conclusion: Our findings indicate an association of a high carbohydrate diet with increased risks for metabolic syndrome components. Conduct of future studies would be necessary in order to explore the underlying mechanism and to confirm our findings in a prospective study.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.2 no.1
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• pp.51-57
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• 2009

Blind equalization techniques have been widely used in wireless communication systems. In this paper, we investigate the information potentials in the criterion of minimizing Euclidian distance between two PDFs criterion for adaptive blind equalizers and evaluate BER performance of the method that has utilized an appropriate balance between the two information potentials, one from output samples and ramdomly generated desired samples at the receiver and another from the interactions among output samples. The balanced information potential method has shown in the BER performance results that it can produce significantly enhanced BER performance in blind equalization applications.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3435-3440
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• 2010

Unlike the electric method capable of checking only product defect, the real time optical metrology is suggested for measuring and visualizing vibration with respect to position of surface acoustic wave in RF device. The measuring limits and conditions for surface acoustic wave is given, and the interference and diffraction due to RF signal are analyzed by optical interpretation. A single mode laser and a 105MHz-center-frequency repeater filter were employed for experiments and theoretical analysis. In this paper, the optical metrology providing visual energy distribution and real time inspection for surface acoustic wave is proposed for development of high quality multi-service and multi-frequency RF module.

• International Journal of Highway Engineering
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• v.7 no.1 s.23
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• pp.49-61
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• 2005

The dynamic modulus of hot mix asphalt can be determined according to the different combinations of testing temperature and loading frequency. The superposition rule is adapted to get the master curve of dynamic modulus for each hot mix asphalt. There are couple of different methods to get the shift factor which is a key for making the master curve. In this paper, Arrehnius, 2002 AASHTO, and experimental method was employed to get the master curve. Evaluation of dynamic modulus for 25mm base course of hot mix asphalt with granite aggregate and two asphalt binders(AP-3 and AP-5) was carried out. Superpave Level 1 Mix Design with gyratory compactor was adopted to determine the optimum asphalt binder content(OAC) and the measured ranges of OAC were between 4.1% and 4.4%. UTM was used for laboratory test. The dynamic modulus and phase angle were determined by testing on UTM, with 5 different testing temperature(-10, 5, 20, 40, & $55^{\circ}C$) and 5 different loading frequencies(0.05, 0.1, 1, 10, 25 Hz). Using the measured dynamic modulus and phase angle, the input parameters of Sigmoidal function equation to represent the master curve were determined and these will be adopted in FEM analysis for asphalt pavements. The shift factor and activation energy for determination of master curve were calculated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.738-744
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• 2017

Recently, the installation of energy storage systems (ESSs) has increased in parallel with the extension of renewable energy resources. However, there has been no concrete analysis ofthe performance verification and economic evaluation of ESSs,which makes it difficult to perform aneffective installation and operation of an ESS. In particular, there are no international technical standards and guidelines on electric ESS for frequency regulation applications. Therefore, acomprehensive study on the power quality, impact on grid, extent of contribution, and cost benefit study of ESS are strongly being required. Under these backgrounds, this paper proposes a performance verification algorithm on ESS for frequency regulation application based on ananalysis of the AGC(Automatic Generation Control) performance verification method of PJM in USA. In addition,this paper proposes an economic evaluation algorithm on a 500 MW installation of ESS for frequency regulation applications using the account settlement of an expensive gas-fired generation plant and coal-fired power generation plant. From the simulation with real ESS operation data and 500 MW installation case, it wasconfirmed that the ESS showssuperior performance toany other conventional generators and provides anannual benefit of 500 MW ESS are between 345~429 billon won.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.1
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• pp.63-76
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• 2015

The purpose of this study is to suggest performance levels, a test method, and assessment criteria for the performance assessment to allow standardized tests for rockfall protection systems. The range of rockfall impact energy was determined by using domestic rockfall data and a total of 9 performance levels from 50kJ to 1500kJ were suggested. The performance assessment is implemented by two types of full-scale free-fall impact tests to investigate the serviceability and the maximum capacity as in European and American standards. It was considered to be reasonable that the specimens of rockfall protection systems consist of 3 spans and the concrete block of a polyhedron with 26 faces, similar to spheres, impacts at the center of a center span. Assessment criteria were constructed to investigate whether a rockfall penetrated rockfall protection systems and whether the deformed specimen encroached on the roadway or obstructed the vehicle traffic.

• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.4
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• pp.37-48
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• 2010

The seismic control effect of reinforced concrete structures with low energy dissipating capacity due to stiffness degradation is investigated through nonlinear time history analysis. The primary structure is idealized as a SDOF system of modified Takeda hysteresis rule and an elasto-perfectly-plastic nonlinear spring is added to represent a hysteretic damping device. Based on statistics of the numerical analysis, equivalent linearization techniques are evaluated, and empirical equations for response prediction are proposed. As a result, estimation of the ductility demand with proposed empirical equations is more desirable than the equivalent linearization techniques. The optimal yield strengths based on empirical equations are significantly different from the optimal yield strength of elasto-perfectly-plastic systems. Also, the results indicate that the reduction effect of the ductility demand is more remarkable for smaller natural periods.

• Journal of Practical Agriculture & Fisheries Research
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• v.20 no.2
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• pp.49-56
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• 2018

Recently, attempts have been made by dairy farms to shorten the time until the first estrus by feeding animals a high-energy diet during the heifer period. Energy consumption during the heifer period has been shown to be related to milk yield and reproductive performance. The present study was conducted to analyze the relationship between reproductive performance and energy intake in heifers. There were no differences in height or body weight between animals that were fed the Korean standard diet versus a high energy diet (110% of the Korean standard). However, there was a difference in the timing of the first estrus: 329.3 days under normal energy conditions versus 311 days under high energy conditions. There was no difference in the number of artificial insemination per gestation, but both the rate of female calf production and the weight of individual female calves increased in response to the high energy diet. Based on these results, it may be predicted that the reproductive performance of dairy cows will increase when the animals are fed a high energy diet (110% of the Korean standard). These results demonstrate a correlation between the amount of energy consumed and reproductive performance, and will be of great value to the dairy farming industry.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2001.11a
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• pp.20-20
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• 2001

우리나라 제지산업은 화학펼프의 80%를 수입에 의존하고 었으나 고지회수율 및 이용율이 세계적으로 볼 때 매우 높은 환경친화적 산업이다. 고지 재활용 공정 중에 서 가장 핵심적인 공정인 부유부상 공정은 고상계의 표면특성 차이를 이용하여 소수성 의 잉크업자를 기포에 부착시켜 부상을 통하여 제거하는 공정이다. 고지 사용의 고도화 를 위해서는 부유부상 공정의 효율 증대가 절실히 요구되고 있다. 또한 부유부상 공정 의 핵심적인 인자로 부유부상을 통하여 제거되는 고형물질의 표면 특성 특히 소수화도 가 중요하다는 것은 보고된 바 있으나 부유부상에 필요한 표면 특성의 존재 여부와 표 면 에너지와 부유부상 효율의 관계 등에 관한 기본적인 연구가 더욱 필요한 실정이다. 이에 본 연구에서는 부유부상 공정을 기초과학적 측면에서 규명하기 위해 마 이 크로 크리 스탈린 셀룰로오스(Microcrystalline cellulose: MCC)를 모델 물질로 사용하 고 이들의 표면특성을 접촉각 측정을 통하여 평가하였다. 친수성의 표면 특성을 지닌 M MCC의 표면 특성을 소수성으로 바꾸기 위하여 AKD(alkyl ketene dimer)의 함량별로 사이징 처리하여 소수성을 지닌 잉크를 모벨링 하고 친수성 MCC를 염색시약을 이용 하여 흑색으로 염색함으로써 소수화 된 MCC와의 색차를 두어 섬유를 모델링 하였다. 이렇게 제조된 MCC의 소수화 정도를 평가하기 위하여 분말상태인 MCC를 pellet으로 제조하여 각기 다른 표면장력과 표변특성을 지난 용액을 이용하여 Advancing Contact A Angle을 측정하고 다양한 방법으로 이를 분석하여 시료의 표면에너지를 평가하였다 그 리고 부유부상 셀내의 액상의 이온강도와 표면장력 등 화학적인 인자에 의한 부유부상 분리효과를 평가하였다.있었다 (그림 2). 칼렌다는 종이를 높은 전단력과 압축력으로 변형시키는데 비해 도침은 단순히 압축 압력만을 종이에 가하는 것이 다르다고 볼 수 있는데, 라 이너지와 백상지가 같은 조건하에서 왜 이러한 큰 차이를 보이는 이유를 아직 알수 없다.해 동일한 공정 데이터들올 이용하여 보편적으로 사용하는 통계기법 중의 하나인 주성분회귀분석을 실시하였다. 주성분 분석은 여러 개의 반응변수에 대하여 얻어진 다변량 자료의 다차원적인 변 수들을 축소, 요약하는 차원의 단순화와 더불어 서로 상관되어있는 반응변수들 상호간 의 복잡한 구조를 분석하는 기법이다. 본 발표에서는 공정 자료를 활용하여 인공신경망 과 주성분분석을 통해 공정 트러블의 발생에 영향 하는 인자들을 보다 현실적으로 추 정하고, 그 대책을 모색함으로써 이를 최소화할 수 있는 방안을 소개하고자 한다.금 빛 용사 둥과 같은 표면처리를 할 경우임의 소재 표면에 도금 및 용 사에 용이한 재료를 오버레이용접시킨 후 표면처리를 함으로써 보다 고품질의 표면층을 얻기위한 시도가 이루어지고 있다. 따라서 국내, 외의 오버레이 용접기술의 적용현황 및 대표적인 적용사례, 오버레이 용접기술 및 용접재료의 개발현황 둥을 중심으로 살펴봄으로서 아직 국내에서는 널리 알려지지 않은 본 기 술의 활용을 넓이고자 한다. within minimum time from beginning of the shutdown.및 12.36%, $101{\sim}200$일의 경우 12.78% 및 12.44%, 201일 이상의 경우 13.17% 및 11.30%로 201일 이상의 유기의 경우에만 대조구와 삭제 구간에 유의적인(p<0.05) 차이를 나타내었다.는 담수(淡水)에서 10%o의 해수(海水)로 이주된지 14일(日) 이후에 신장(腎臟)에서 수축된

• Journal of radiological science and technology
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• v.40 no.1
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• pp.93-99
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• 2017

Dose enhancement effects at megavoltage (MV) X and ${\gamma}-ray$ energies, and the effects of different energy levels on incident energy, dose enhancement agents, and concentrations were analyzed using Monte Carlo simulations. Gold, gadolinium, Iodine, and iron oxide ($Fe_2O_3$) were compared as dose enhancement agents. For incident energy, 4, 6, 10 and 15 MV X-ray spectra produced by a linear accelerator and a Co-60 ${\gamma}-ray$ were used. The dose enhancement factor (DEF) was calculated using an ICRU Slab phantom for concentrations of 7, 18, and 30 mg/g. The DEF was higher at higher concentrations of dose enhancement agents and at lower incident energies. The calculated DEF ranged from 1.035 to 1.079, and dose enhancement effects were highest for iron oxide, followed by iodine, gadolinium, and gold. Thus, this study contributes to improving the therapeutic ratio by delivering larger doses of radiation to tumor volume, and provides data to support further in vivo and in vitro studies.