• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.26 no.5
• /
• pp.231-239
• /
• 2014

This paper represents a method of existing building energy simulation using energy audit data. Energy audit must be carried out for reasonable analysis, because characteristics of existing buildings such as efficiency of fan, pump, flow rate, pressure, COP and operating schedule could be changed during the building operation. These building characteristics should be measured to estimate actual energy consumption of the existing building. In this study, we conducted energy audit and calculated energy savings for a 7-stories building as a case-study. The energy audit data were used to calibrate the building model of EnergyPlus simulation. Baseline model validated according to M&V guideline index. As a result, building characteristics are significant parameters making a big impact on energy savings in existing buildings.

• KIEAE Journal
• /
• v.12 no.6
• /
• pp.39-47
• /
• 2012

Recently, the green building and energy connection system are establishing. But, National certification system for environment-Friendly Buildings is indicated hangup about energy efficiency of building. Commissioning, energy conservation, renewable energy, carbon dioxide emissions, it is determined that the energy associated with LEED and GBCC four items of the comparative analysis showed the following results. First, on the practical performance of the system after the completion of commissioning of the energy associated with the system completed until after the final performance for secure operation from the planning stage to verify and document systematically how to perform, but the domestic review and verification is incomplete. Second, the use of energy-saving and renewable energy is directly related to the energy consumption of the building, but GBCC the strengthening of standards on how to evaluate it is deemed necessary. Finally, the evaluation of the reduction of carbon dioxide emissions, LEED Unlike GBCC the life-cycle of the system without considering the global warming index only because a substantial step in the operating efficiency can not be assessed. Based on this study GBCC energy savings through efficiency to actively carry out research through a systematic analysis of the basic guidelines to proceed.

• Journal of the Korean Solar Energy Society
• /
• v.40 no.4
• /
• pp.1-11
• /
• 2020

The Journal of the Korean Solar Energy Society is the first journal in South Korea that adopts wind energy as one of its subjects. Since 2000, more than 140 papers on wind energy have been published in the journal, which accounts for 8.5% of the total publication. However, in recent years, the number of published papers on wind energy has been decreasing steadily, and a reason for this decline is the significant dependence on a few specific institutions and authors. In this study, wind energy subjects were classified using the frequency analysis of the subject words extracted from the title, keywords, and abstract of wind energy papers using the text mining technique. In addition, the Korea Citation Index was used to perform quantitative level evaluation by subject and institution and to analyze the trends and characteristics of the wind energy field. Therefore, it was identified that in terms of the number of publications and citations, the main subject areas were resource/micrositing and policy/potential.

• Korean Journal of Community Nutrition
• /
• v.10 no.6
• /
• pp.880-891
• /
• 2005

The purpose of this study was to investigate nutrients intakes and nutritional quality of Adults and Elderly People in an island area (Wando). A three-day dietary intakes survey, using a 24 hour recall method was obtained from 187 subjects aged 46 to 84 (mean age 65.3) living in an island area (Wando). Nutient intakes were analyzed using CAN-Pro soft program and compared to Korean RDA. The quality of nutrients was assessed by analyzing nutrient adequacy ratio (NAR), mean adequacy ratio (MAR), and index of nutritional quality (INQ). The average daily mean energy intakes were 1869.0 kcal for males and 1943.9 kcal for females, respectively. Daily intakes of protein for males and females were 28.0 and 30.4 g and those of fat were 31.5 and 28.51 g, respectively. Nutrient consumed below $75\%$ of Korean RDA was protein, vitamin A, Ca and Zn in both males and females. Average CPF ratio of males and females were 78.8 : 6.0 : 15.1 and 80.0 : 6.4 13.4, respectively. Energy intake ratio from protein was significantly higher in over 60 years males. Carbohydrate dependency decreased with age. Protein dependency increased with age. Nutrient adequacy ratio (NAR) of energy, protein vitamin A and vitamin E were increased with age in males. The mean adequacy ratio (MAR), an index of overall dietary quality, were not significantly different by age group. Average MAR for males and females was 0.77 and 0.78, respectively. The index of nutritional quality (INQ) showed the tendency to decrease with age. Especially, there were significantly decreases in INQ of all nutrients, except protein, with age. Based on these results, it is evident that people in the island area did not consume enough nutrients. Specially, dietary intake of protein, vitamin A, vitamin E, and Ca were not adequate. (Korean J Community Nutrition 10(6) : $880\∼891$, 2005)

• Tunnel and Underground Space
• /
• v.24 no.2
• /
• pp.166-175
• /
• 2014

In this study, the thermal environment in a large scale coal mine located in Taebaek, Gangwondo was assessed by a field survey. In order to estimate the thermal environment, various heat stress indices such as WBGT, HSI, ESI, KATA index and effective temperature were investigated. Correlation analysis was also conducted. It was found that the thermal environment in most workplace was high. In particular, the correlation coefficient between HSI reflected in physiological fatigue characteristic and the maximum sweat evaporation heat was -0.834. This shows that the correlation coefficient have the most influence on HSI index. The factor which has the most influence on the maximum sweat evaporation heat is velocity of air. The thermal environment of high-depth coal mines is likely to be improved by installing a structure that enables the maximum prevention of extended digging, air doors, or the leakage of the inflow of air in the first shaft.

• Journal of the korean society of oceanography
• /
• v.37 no.1
• /
• pp.10-19
• /
• 2002

The detailed structure of a tidal front and its ebb-to flood variation in the main tidal channel of the Kyunggi Bay in the mid-west coast of Korea were investigated by analyzing CTD data and drifter trajectories collected in late July 1999. A typical tidal front was formed in water about 60 m deep at the mouth of the channel. Isotherms and isohalines in the upper layer above the seasonal pycnocline in the offshore stratified zone inclined upward to the sea surface to form a surface front, while those in the lower layer declined to the bottom front. The location of the front is consistent with $100 S^3/cm^2$ of the mixing index H/U defined by Simpson and Hunter (1974), where H is the water depth and U is the amplitude of tidal current. The potential energy anomaly in the frontal zone varied at an ebb-to flood tidal cycle, showing a minimum at slack water after ebb but a maximum at slack water after flood. This ebb-to flood variation in potential energy anomaly is not accounted for by the mixing index. We conclude that on- and offshore displacement of the water column by tidal advection is responsible for the ebb-to-flood variation in the frontal zone.

• Geomechanics and Engineering
• /
• v.14 no.4
• /
• pp.367-376
• /
• 2018

Samples composed of coal and rock show different mechanical properties of the pure coal or rock mass. For the same coal seam with different surrounding rocks, the frequency and intensity of rock burst can be significantly different in. First, a method of measuring the strain variation of coal in the coal-rock combined sample was proposed. Second, laboratory tests have been conducted to investigate the influences of rock lithologies, combined forms and coal-rock height ratios on the deformation and failure characteristics of the coal section using this method. Third, a new bursting liability index named combined coal-rock impact energy speed index (CRIES) was proposed. This index considers not only the time effect of energy, but also the influence of surrounding rocks. At last, a new approach considering the influences of roof and/or floor was proposed to evaluate the impact capability of coal seam. Results show that the strength and elastic modulus of coal section increase significantly with the coal-rock height ratio decreasing. In addition, the values of bursting liability indexes of the same coal seam vary greatly when using the new approach. This study not only provides a new approach to measuring the strain of the coal section in coal-rock combined sample, but also improves the evaluation system for evaluating the impact capability of coal.

• Korean Journal of Radiology
• /
• v.19 no.6
• /
• pp.1077-1088
• /
• 2018

Objective: To correlate CT parameters on detector-based dual-energy CT enterography (DECTE) with Crohn's disease activity index (CDAI) and externally validate quantitative CT parameters. Materials and Methods: Thirty-nine patients with CD were retrospectively enrolled. Two radiologists reviewed DECTE images by consensus for qualitative and quantitative CT features. CT attenuation and iodine concentration for the diseased bowel were also measured. Univariate statistical tests were used to evaluate whether there was a significant difference in CTE features between remission and active groups, on the basis of the CDAI score. Pearson's correlation test and multiple linear regression analyses were used to assess the correlation between quantitative CT parameters and CDAI. For external validation, an additional 33 consecutive patients were recruited. The correlation and concordance rate were calculated between real and estimated CDAI. Results: There were significant differences between remission and active groups in the bowel enhancement pattern, subjective degree of enhancement, mesenteric fat infiltration, comb sign, and obstruction (p < 0.05). Significant correlations were found between CDAI and quantitative CT parameters, including number of lesions (correlation coefficient, r = 0.573), bowel wall thickness (r = 0.477), iodine concentration (r = 0.744), and relative degree of enhancement (r = 0.541; p < 0.05). Iodine concentration remained the sole independent variable associated with CDAI in multivariate analysis (p = 0.001). The linear regression equation for CDAI (y) and iodine concentration (x) was y = 53.549x + 55.111. For validation patients, a significant correlation (r = 0.925; p < 0.001) and high concordance rate (87.9%, 29/33) were observed between real and estimated CDAIs. Conclusion: Iodine concentration, measured on detector-based DECTE, represents a convenient and reproducible biomarker to monitor disease activity in CD.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.25 no.5
• /
• pp.627-633
• /
• 2019

This study aimed to predict the resistance and propulsion performance of a ship using computational fluid dynamics (CFD) and a database as well as establish an assessment method for the energy efficiency design index (EEDI) using the results. First, the total resistance of the studied ship is obtained using CFD. A flow analysis is conducted with the free surface and trim and sinkage using a commercial CFD code (STAR-CCM+). The effective power of the ship is assessed based on the CFD results. The quasi-propulsive efficiency is calculated from an empirical prediction equation using experimental data and similar material. Finally, a general calculation program for the EEDI is established based on the hydrodynamic results, ship information for principal particulars, conversion factor of $CO_2$ for fuels, and fuel consumption.

• Journal of the East Asian Society of Dietary Life
• /
• v.15 no.1
• /
• pp.29-39
• /
• 2005

The obesity incidence rate of children in Korea has increased from 2 to 3% in 1970 to 15% in 2004. The purpose of this study was to evaluate the effect of diet on obesity, and serum cholesterol and triglyceride concentrations by obese index in Korean elementary school students. The subjects were three hundred and thirteen students(male 157, female 156). Height, weight and body fat were measured. Dietary records by the 24-hr recall method were taken for 3 days, and serum cholesterol and triglyceride concentrations were determined. The obesity index was calculated by the Korean of Pediatrics Association standards. Nutrient intakes were calculated by CAN PRO. Almost twenty percent(19.8%) of the subjects were underweight, 60.1 % were normal, 10.2% were overweight and 9.9% were obesity. The obesity incidence rate of the males was not different from the females. Energy and nutrients intakes containing fatty acids were not significantly different by the obesity index. All the subjects had 59.7%～61.1% of carbohydrate and 24.2%～25.6% of fat for energy. Serum cholesterol concentrations of the obesity group(177.3 mg/dl) was higher than those of the underweight group(161.8 mg/dl) and normal weight group(163.5 mg/dl) and overweight group(163.8 mg/dl). Twenty nine percent of the obesity group had serum cholesterol concentrations over 200mg/dl, as compared with 4.8% of the normal and underweight group. Serum triglyceride in the obesity group(103.0mg/dl) was higher than those of the underweight group(79.7 mg/dL), normal weight group(81.0 mg/dl) and overweight group(81.1 mg/dl). Serum total cholesterol concentrations were correlated with the obese index, PIBW, R hrer index at p<0.001, with BMI at p<0.01 and with waist/hip ratio at p<0.05. Serum triglyceride concentrations were correlated with the obese index, PIBW, R hrer index at p<0.01. It is concluded that obesity increases serum total cholesterol concentrations and triglyceride concentrations, and that the obesity preventive program for normal weight children, and weight reduction program for obese children are necessary for elementary school children's education.