• Journal of Nutrition and Health
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• 제28권9호
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• pp.893-903
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• 1995

This study was attempted to estimate seasonal variations of physical activity level, energy balance & body composition of 38 rural women, aged 31 to 67yrs in three seasons ; farming season(June), harvesting season(October), nonfarming season(February) Energy intake, energy expenditure and body composition were assessed using questionnaire, daily activity diary & bioelectrical impedance. The type of activities & the period of the spent on each activity were changed significantly with the seasons. Daily mean duration(min) of farming activity was significantly higher in June & October than in February(p<0.005) & daily mean energy expenditure for farming activity was significantly high in June & low inFebruary (p<0.005). Daily mean energy expenditure was 2892.9㎉ in June, 2487.4㎉ in October and 2130.9㎉ in February and changed significantly in three seasons(p<0.005). Daily mean energy intake was significantly higher in June(=1950.3㎉) & October (=1946.9㎉) than in February(=1423.3㎉)(p<0.005). According to RDA for koreans, the level of physical activity fell into exceptional activity category in June, heavy in October, moderate in February. Mean energy balance was negative in all seasons ; 0.682 in June, 0.812 in October and 0.698 in February. In three seasons mean body weight, mean obesity rate and mean body mass index(BMI) were not changed significantly. But there were significant seasonal variations in body fat(%) & lean body mass(LBM)(%). The mean percentage of body fat(%) was within normal range(24.44-24.79%) & the mean percentage of lean body mass(LBM)(%) representing long term physical activity was significantly higher in June(75.56%) & October(75.21%) & October (75.21%) than in February(72.75%)(p<0.05).

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 춘계학술대회 논문집
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• pp.181-188
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• 2000

This paper describes the energy absorption of a square tube under axi compression by using the finite element method. The overall deformations and lo buckling modes of tube was discussed by "plastic hinge concep Force-displacement function was plotted to show various state that depended or time. Also, mean crush load was expressed as a type of section geometry a material property using dimensional analysis. To verify the energy absorption and the effects of dimensions, The standards Wt used as related density and specific energy, mean crushing load and the resL were discussed by the relation between crush load and deformation, the relati between related density and specific energy, the relation between crush load a mean crush load, the relation between mean crush load and specific energy.ergy.

• 한국태양에너지학회 논문집
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• 제30권2호
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• pp.54-64
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• 2010

Interest in new and renewable energies like solar energy and wind energy is increasing throughout the world due to the rapidly expanding energy consumption and environmental reasons. An essential requirement for wind force power generation is estimating the size of wind energy accurately. Wind energy is estimated usually using meteorological data or field measurement. This study attempted to estimate wind energy density using meteorological data on daily mean wind speed and the Weibull parameters in Seoul, a representative inland city where over 60% of 15 story or higher apartments in Korea are situated, and Busan, Incheon, Ulsan and Jeju that are major coastal cities in Korea. According to the results of analysis, the monthly mean probability density distribution based on the daily mean wind speed agreed well with the monthly mean probability density distribution based on the Weibull parameters. This finding suggests that the Weibull parameters, which is highly applicable and convenient, can be utilized to estimate the wind energy density distribution of each area. Another finding was that wind energy density was higher in coastal cities Busan and Incheon than in inland city Seoul.

• Journal of Nutrition and Health
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• 제27권4호
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• pp.336-346
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• 1994

balance and to estimate daily energy requirement in 43 Korean female college students maintaining their usual diet and activity level. Energy intake and expenditure were measured in two separate periods about one month apart, each period lasting for 3 days. All the subjects participated in both periods. Energy intake was assessed by two methods ; weighed diet record and duplicate portion analysis of diet minus fecal and urinary excretion. Mean daily energy intake level calculated from diet records was 28.5 kcal/kgB.W(1, 476 kcal/day), and similar to the level of 27.8 kcal/kgB.W(1, 438 kcal/days) obtained from the chemical analysis of duplicate portions. Mean daily energy expenditure, calculated from activity records of each subject, was 34.6 kcal/kgB.W, or 1.39 times BMR, which corresponds to light activity level. Mean daily energy balance of subjects was -5.9 kcal/kgB.W. Mean daily requirement of energy, calculated from the activity records of the subjects, was 34.6 kcal/kgB.W, similar to the level of the Korean RDA for light activity level. The results of this study indicate that 1) the activity level of the study subjects corresponds to the sedentary level ; 2) present Korean RDA for energy for light activity is adequate for the subjects ; and 3) the subjects should increase their energy intake since they are largely in negative energy balance.

• 대한치과보철학회지
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• 제34권4호
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• pp.816-822
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• 1996

The purpose of this study was to determine whether there was any difference in the mean porosity of denture base resin cured by microwave energy, when the liquid monomers of denture resin(K-33 : methyl methacrylate for conventional water bath curing or Acron MC : special monomer for microwave curing) and/or the thicknesses of denture base($5{\times}10{\times}60mm\;or\;10{\times}10{\times}60mm$) were varied. The mean porosities of k-33 specimens cured in water bath with two different thicknesses were used as control. The results were as follows : 1. Regardless of specimen thickness, Acron MC cured by microwave energy showed the least mean porosity, followed by K-33 cured by water bath heat, and K-33 cured by microwave energy showed the highest level of mean porosity(P<0.05). 2. In both K-33 and Acron MC cured by microwave energy the mean porosities of 5mm thickness groups were lower than those of 10mm thickness groups(P<0.05). But no significant difference was found in mean porosity between 5mm thickness and 10mm thickness of water bath heat cured groups made of K-33(P>0.05).

• 한국자동차공학회논문집
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• 제14권3호
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• pp.133-141
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• 2006

The Low cycle fatigue behavior of 11.7Cr-1.1Mo heat-resisting steel has been investigated under strain-controlled conditions with mean stresses at room temperature and $300^{\circ}C$. For the tensile mean stress test, the initial high tensile mean stress generally relaxed to zero at room temperature, however, at $300^{\circ}C$ initial tensile mean stress relaxed to compressive mean stress. Low cycle fatigue lives under mean stress conditions are usually correlated using modifications to the strain-life approach. Based on the fatigue test results from different stain ratio of -1, 0, 0.5, and 0.75 at room temperature and $300^{\circ}C$, the fatigue damage of the steel was represented by using cyclic strain energy density. Total strain energy density considering mean stress indicated well better than not considering mean stress at $300^{\circ}C$. Predicted fatigue life using Smith-Watson-Topper's parameter correlated fairly well with the experimental life at $300^{\circ}C$.

• Earthquakes and Structures
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• 제26권3호
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• pp.219-228
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• 2024

This study examines damping modification factors (DMFs) of elastic input energy spectra corresponding to a set of 116 earthquake ground motions. Mean input energy per mass spectra and mean DMFs are presented for both considered ground motion components. Damping ratios of 3%, 5%, 10%, 20%, and 30% are used and the 5% damping ratio is considered the benchmark for DMF computations. The geometric mean DMFs of the two horizontal components of each ground motion are computed and coefficients of variation are presented graphically. The results show that the input energy spectra-based DMFs exhibit a dependence on the damping ratio at very short periods and they tend to be nearly constant for larger periods. In addition, mean DMF variation is obtained graphically for also the damping ratio, and mathematical functions are fitted as a result of statistical analyses. A strong correlation between the computed DMFs and the ones from predicted equations is observed.

• Asian Pacific Journal of Cancer Prevention
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• 제16권17호
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• pp.7795-7801
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• 2015

The aim of the present research was to establish primary characteristics of electron beams for a Varian 2100C/D linear accelerator with recently developed PRIMO Monte Carlo software and to verify relations between electron energy and dose distribution. To maintain conformity of simulated and measured dose curves within 1%/1mm, mean energy, Full Width at Half Maximum (FWHM) of energy and focal spot FWHM of initial beam were changed iteratively. Mean and most probable energies were extracted from validated phase spaces and compared with related empirical equation results. To explain the importance of correct estimation of primary energy on a clinical case, computed tomography images of a thorax phantom were imported in PRIMO. Dose distributions and dose volume histogram (DVH) curves were compared between validated and artificial cases with overestimated energy. Initial mean energies were obtained of 6.68, 9.73, 13.2 and 16.4 MeV for 6, 9, 12 and 15 nominal energies, respectively. Energy FWHM reduced with increase in energy. Three mm focal spot FWHM for 9 MeV and 4 mm for other energies made proper matches of simulated and measured profiles. In addition, the maximum difference of calculated mean electrons energy at the phantom surface with empirical equation was 2.2 percent. Finally, clear differences in DVH curves of validated and artificial energy were observed as heterogeneity indexes were 0.15 for 7.21 MeV and 0.25 for 6.68 MeV. The Monte Carlo model presented in PRIMO for Varian 2100 CD was precisely validated. IAEA polynomial equations estimated mean energy more accurately than a known linear one. Small displacement of R50 changed DVH curves and homogeneity indexes. PRIMO is a user-friendly software which has suitable capabilities to calculate dose distribution in water phantoms or computerized tomographic volumes accurately.

• Journal of Nutrition and Health
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• 제28권4호
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• pp.259-267
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• 1995

A study was conducted to investigate nitrogen balance and to estimate daily nitrogen requirement in 43 Korean female college students students maintaining their usual diet and activity levels. Nitrogen intake and excretion were measured in two separate peroids about one month apart, each period lasting for 3 days. Nitrogen intake was assessed by duplicate portion analysis of diet, and N excretion in faces and urine were measured during the study period. Mean daily nitrogen intake level was 129.3mg/kg B.W and the apparent digestibility of nitrogen was 76%. Mean daily urinary nitrogen excretion was 113.5mg/kg BW. 895 of total nitrogen intake. Mean daily nitrogen balance of subjects was -14.5mg/kg BW. Mean daily requirements of nitrogen for 0 balance, calculated by regression analysis of N balance and energy-adjusted N intake. were 1) 197.mg/kg B.W with the present energy intake level of the study subjects. 2) 157mg/kg B.W when energy intake is sufficient to maintain energy balance, and 30 130mg/kg B.W. when energy intake is Korean RDA level for moderate activity. When energy intake level is sufficient to meet their requirement, daily protein requirement for 0 balance is about 1.0g/kg B.W. The results of this study indicate that nitrogen intake level of young female college students is not sufficient to meet their requirements, and they should increase protein intake together with increase in energy intake.

• Journal of Nutrition and Health
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• 제33권2호
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• pp.193-201
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• 2000

This study was conducted to investigate the effectiveness of nutrition counseling on the dietary intake and nutritional status cancer patients undergoing radiotherapy treatment. The study was conducted over 6 week period and included 104 patients : 66 received nutrition counseling as the variable group of 42 male and 24 female and 38 patients received no counseling as the control group of 19 male and 19 female. Nutrition counseling was accompanied with the radiation therapy and adminstered via counseling session and distribution of printed material during radiation therapy for 6 weeks. Nutrition counseling aimed at maintaining a balanced diet and preventing weight loss of subjects, guideline used for energy and protein intake were 35kcal/kg IBW and 1.5-2.0g/kg IBW, respectively. Over the course of the study, the counseling group increased significantly in comparison to the control group's energy intake, evidenced by the counseling group's initial mean daily energy intake of 1932.0kcal, and 4 and 6 week mean energy intake values of 2046.6kcal, 2066kcal, respectively. But mean energy values of control group was 1614.3kcal at 4 week. Th energy intake per weight values and protein intake per weight values for initial, 4 and 6 week intervals for counseling group were 33.2kcal/kg, 33.7kcal/kg, 34.0kcal/kg, and 1.48g/kg, 1.58g/kg, 1.59g/kg, respectively. Based on results, nutrition counseling had positive effects on both the variety of diet and energy intake of the variable group, mostly due to an increase in dairy product and egg consumption. In addition, the percentage of counseling group patients who consumed all 5 food group increased from 48.5% to 54.5%. Sufficient energy intake and protein consumption seem to be important factors in weight loss prevention, evidenced by weight gain by subjects in the counseling group who had 36.1kcal/kg/day mean energy intake and 1.77g/kg/day mean protein intake after 4 weeks. Counseling group subjects experiencing weight loss had lower intake and 1.77g/kg/day mean protein intake after 3 weeks. Counseling group subjects experiencing weight loss had lower intakes of 29.3kcal/kg/day for energy and 1.33g/kg/day for protein during the same period. Another significant factor in weight loss prevention of the counseling group could be the variety of diet. The dietary variety scores(DVS) of both counseling and control groups differed significantly : the counseling group had a mean score of 34 while the control group of patients. At the end of the study, the mean percentage of subjects within each group having a DDS 5 was higher in the counseling group (54.5% v.s. 24.0%). In this study, nutrition counseling for cancer patients undergoing radiation therapy proved to be effective in preventing weight loss, a major complication during radiotherapy. Nutrition counseling not only increased protein and energy intake, but also had desirable effects on variety or diversity of diet.