• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.8-12
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• 2009

The Knowledge of the solar radiation components are essential for modeling many solar energy systems. This is particularly the case for applications that concentrate the incident energy to attain high thermodynamic efficiency achievable only at the higher temperatures. In order to estimate the performance of concentrating thermal systems, it is necessary to know the intensity of the beam radiation, as only this component can be concentrated. The Korea Institute of Energy Research(KIER) has began collecting solar radiation component data since August, 2002. KIER's component data will be extensively used by concentrating system users or designers as well as by research institutes. The Result of analysis shows that the annual-average daily diffuse radiation on the horizontal surface is $1,458cal/m^2$ and daily direct radiation on the horizontal surface is $1,632cal/m^2$ for all over the 16 areas in Korea.

• Journal of the Korean Solar Energy Society
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• v.34 no.1
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• pp.64-71
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• 2014

This study is to perform economic analysis of a PVT-GSHP (Photovoltaic Thermal-Ground Source Heat Pump) system compared to the conventional system which consists of a boiler and a chiller. This research has simulated, developed and analyzed four systems for application in a residential and an office building which was based on the hourly EPI (Energy Performance Index, $kWh/m^2yr$). Case 1 includes a boiler and a chiller to meet heating and cooling demands for a house. Case 2 is the same conventional system as Case 1 for a office. Case 3 is simple summation of Case 1 and 2. And Case 4 is utilizing a PVT-GSHP to meet the combined loads of the house and office. The economic evaluation study was based on IEA ECBCS Annex 54 subtasks C economic assessment methods. This study indicated that PVT-GSHP system can save a building's energy up to 53.9%. Also the SPB (Simple Payback) of the PVT-GSHP system with 0%, 50% initial incentive was 14.5, 6.7 year respectively.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.129-136
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• 1997

The automated ball indentation(ABI) test was utilized to develop a semi-nondestructive method for estimating the fracture toughness( $K_{JC}$ ) in the transition temperature range. The key concept of the method is that the indentation deformation energy to the load at which the mean ball-specimen contact pressure reaches the fracture stress is related to the fracture energy of the material. ABI tests were performed for the reactor pressure vessel(RPV) base and weld metals at the temperatures of-15$0^{\circ}C$~$0^{\circ}C$ and the fracture toughness (estimated $K_{JC}$ ) was calculated from the indentation load-depth data. For all steels the temperature dependence of the estimated fracture toughness was almost the same as that ASTM $K_{JC}$ master curve The reference temperatures( $T_{o}$)of the steels were determined form the estimated $K_{JC}$ versus temperature curves. The reference temperature was well correlated with the index temperature of 41J Charpy impact energy( $T_{41J}$).).).

• Journal of Nutrition and Health
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• v.49 no.6
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• pp.482-494
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• 2016

Purpose: The objective of the present study was to evaluate nutrient and food group intakes in Korean adults according to energy intake from eating-out. Methods: This study was a cross-sectional study based on the 2013~2014 Korea National Health and Nutritional Examination Survey, and study subjects were 5,186 males (2,151) and females (3,035) aged 19~64 years. Energy intake from eating-out was analyzed using the 24-hour dietary recall method, and groups were classified by quartile according to energy intake from eating-out. Results: Subjects who had more energy intake from eating-out tended to be younger, highly educated, have a higher income, and have higher alcohol consumption. Total energy intake and fat intake density of the highest quartile group of energy intake from eating-out were higher than those of the other groups. However, fiber, vitamin $B_1$, calcium, phosphorus, potassium, and iron intake density levels were significantly lower in the highest quartile group of energy intake from eating-out. The highest quartile group of energy intake from eating-out consumed significantly more meat and beverages compared to the other groups. In addition, regarding diet quality (Index of nutritional quality), significantly lower vitamin $B_1$, calcium, phosphorus, and iron levels were observed in the highest quartile group of energy intake from eating-out compared to those in the other groups. Conclusion: In conclusion, in Korean adults, consumption of eating-out decreased dietary quality, including vitamin $B_1$, calcium, phosphorus, and iron levels. Further studies are needed to confirm these findings.

• Korean Journal of Community Nutrition
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• v.6 no.1
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• pp.51-68
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• 2001

This investigation studied the relationship between Body Mass Index(BMI) and dietary intake, levels of serum lipid, lipoprotein(a) and plasminogen activator inhibitor-1(PAI-1) of 28.449 Korean adults(16.937 men, 11.542 women) from 1995 to 1999. The dietary assessment was conducted using 24-hour dietary records and food frequency questionnaires. During this five year study, the BMI normal-weight group, as a percentage of the annual test population, decreased from 68.0% to 60.2%, while the BMI overweight and obese groups collectively increased from 25.0% to 29.7%. The levels of serum total cholesterol (TC), LDL-cholesterol(LDL-C), Triacylglycerol(TG) and PAI-1 increased as the values of BMI increased, while the levels of HDL-cholesterol(HDL-C) and lipoprotein(a)(men only) appeared to decrease as values of BMI increased. The levels of daily energy intake also increased as values of BMI increased in both men and women. The obese group had significantly higher levels of carbohydrate, protein, fat(men only), and cholesterol intake than those of the normal-weight, underweight, and overweight groups. In men, BMI positively correlated with the levels of macronutrients and cholesterol intake(p＜0.001), % energy of protein, fat, and alcohol intake(p＜0.001), and the levels of serum TC, LDL-C, TG and PAI-1(p＜0.001), while BMI negatively correlated with % energy of carbohydrate intake, and the levels of Lp(a) and HDL-C(p＜0.001). In women, BMI negatively correlated with level of cholesterol(p＜0.01), fat(p＜0.001), alcohol intake(p＜0.05),% energy of fat (p＜0.001), % energy of alcohol intake and level of and HDL-C(p＜0.001). Subjects who had serum TC, LDL-C, HDL-C, and TG levels greater than the standard reference values(TC＞240mg/㎗, LDL-C＞130mg/㎗, HDL-C＞35, TG＞200mg/㎗) exhibited a higher intake of the three macronutrients, iron, calcium, meat, milk and fatty foods than those subjects who had serum lipid concentrations less-than-or-equal-to the standard reference values. Overall, there was positive correlation between the high risk factors of vascular disease variables, dietary intake, and BMI. Prevalence of hypertension and high blood sugar were increased as BMI increased, but the prevalence of hypertension is decreased as the year goes by. These findings showed that dietary intake, level of serum lipids and other vascular disease risk factors increased as BIM increased. Therefore, middle or upper class Korean adults who have high BMI should improve their eating habits. This involve reducing alcohol, animal fat, high carbohydrate foods, and overall food intake, and balancing intake in order to lower vascular disease risk factors, including obesity.

• Nutritional Sciences
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• v.1 no.1
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• pp.70-76
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• 1998

This study was designed to investigate the relationship between body mass index (BMI) and dietary intake, and the relationship between BMI and plasma lipid levels in Korean adults. This study was conducted from January 1 to December 31 of 1997. It consisted of 3781 subjects (men 2402, women : 1379) with the majority between the ages of 40 and 59. The dietary assessment was based upon a twenty-four-hour food record. Subjects were classified into one of four reference BMI groups : underweight ($\leq 20 kg/m^2$), normal (20.1-25.0 kg/$m^2$), overweight (25.1-30.0 kg/$m^2$), and obese (>30 kg/$m^2$). The biochemical assessment included measurements of plasma total cholesterol (TC), HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C), triglyceride (TG), lipoprotein (a), and plasminogen activator inhibitor-1 (PAI-1). The BMI study showed that 60.5% of the men measured were normal and 32.6% of the men were overweight and/or obese subjects. Sixty-four percent of the women were normal and 20.3% of the women measured were overweight and/o. obese subjects. With respect to the daily energy intake of the men and women subjects, the levels of daily energy intake appeared to increase as values of BMI increased. Men of the overweight group had significantly higher protein, fat and cholesterol intake than those of the normal or the underweight groups. The alcohol intake of the men in the overweight group was also significantly higher than that of the men in the underweight group. With respect to percent energy intake of macronutrients, there was no significant difference between the four BMI groups and percent energy intake for all the subjects in the study. The ratio of percent energy intake of carbohydrates : protein : fat : alcohol of the normal women group was 62 : 17 : 20 : 1, respectively. Women apparently had a higher intake of carbohydrates than men (52 : 17 : 19 : 10). With respect to the levels of plasma TC, LDL-C, TG, and HDL-C, the levels of plasma TC, LDL-C and TC appeared to increase as the values of BMI increased, while the level of HDL-C appeared to decrease as values of BMI increased. Levels of lipoprotein (a) appeared to be inversely related to the values of BMI, and levels of PAI-1 appeared to increase as values of BMI increased. The results of this study demonstrate that there is a relationship between dietary intake and BMI, and that there is a relationship between BMI and blood lipids levels.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.4
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• pp.189-196
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• 2010

U-factor and solar heat gain coefficient(SHGC) usually can be used as the index to evaluate the thermal performance. U-factor is a concept for heat loss by the temperature difference between inside and outside, so it's useful to be applied in heating season. But SHGC that indicates the fraction of heat from incident solar radiation that flows through a window by means of optical transmission, as well as absorption, re-radiation and convection is for cooling season. In other words, U-factor and SHGC of windows by cities have to be reflected to select the window of the energy conservation. The purpose of this research is to analyze the energy use impacts by SHGCs of windows for detached house in Inchon and Ulsan through energy simulation by eQUEST.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.9
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• pp.441-448
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• 2005

On-line dynamic security assessment is becoming more and more important for the stable operation of power systems as load level increases. The necessity is getting apparent under Electricity Market environments, as operation of power system is exposed to more various operating conditions. For on-line dynamic security assessment, fast transient stability analysis tool is required for contingency selection. The TEF(Transient Energy Function) method is a good candidate for this purpose. The clustering of critical generators is crucial for the precise and fast calculation of energy margin. In this paper, we propose a new method for fast decision of mode of instability by using stability indices. Case study shows very promising results.

• Earthquakes and Structures
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• v.4 no.2
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• pp.219-239
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• 2013

The present paper aims at studying the seismic response of structures equipped with viscoelastic dampers (VED). The performance of such a passive control system is here analyzed using the energy balance concept, which leads to an optimal design process. The methodology is based on an energy index (EDI) whose maximization permits determination of the optimal mechanical characteristics of VED. On the basis of a single degree of freedom model, it is shown that the maximum value of EDI corresponds to a simultaneous optimization of the significant kinematic and static response quantities, independently of the input. By using the proposed procedure, the optimal design of new and existing structures equipped with VED, inserted in traditional bracing systems, are here analyzed and discussed.

• Sleep Medicine and Psychophysiology
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• v.19 no.1
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• pp.5-10
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• 2012

The release of hormones and the metabolism of human body are controlled by the circadian rhythm related to sleep-wake cycle. Growth hormone, prolactin, thyroid stimulating hormone, cortisol, glucose, and insulin-secretion rates fluctuate according to the sleep-wake cycle. In addition, sleep is related to the appetite regulation and carbohydrate and other energy metabolism. Hypocretin (orexin), an excitatory neuropeptide, regulates waking and diet intake, and the poor sleep increases diet intake. The short sleep duration increases one's body mass index and impairs the function of the endocrine and metabolism, causing increases in the risk of glucose intolerance and diabetes. The poor sleep quality and sleep disorders have similar impact on the metabolic function. In short, the sleep loss and the poor quality of sleep have a detrimental effect on the endocrine and energy metabolism. The improvement of sleep quality by the future research and appropriate clinical treatment would contribute to the decrease of the metabolic diseases such as diabetes.