• Nutrition Research and Practice
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• v.8 no.1
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• pp.81-93
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• 2014

This study was conducted to investigate nutrient consumption by Korean adults in various places. To accomplish this, we used the 1998-2009 Korea National Health and Nutrition Examination Survey (KNHANES). Subjects of this investigation were over 19 years and the study included 37,160 people. The meals were categorized as breakfast, lunch, dinner, and snacks consumed at home, or while eating-out. Investigation of the rate of consumption at serving places based on daily meals and years showed that eating-out generally increased with time. The consumption of meals prepared at home was higher than that of meals consumed anyplace else in 1998, 2001, 2005, and 2007-2009. However, the rate of consumption of home meals decreased from 1998 to 2007-2009, while the rate of eating-out increased during this period. Annual nutrient intake according to serving places with respect to meals, energy, fat, and sodium were significantly lower in home meals than those consumed elsewhere in 2007-2009 relative to 1998. The sodium intake and energy distribution ratio of fat in meals consumed while eating-out increased significantly from 1998 to 2007-2009. The energy, fat and sodium intake and energy contribution ratio of fat consumed in meals at institutions was significantly higher in 2007-2009 than in 1998. Based on these results, additional research is required to develop guidelines for dietary life improvement at each serving place and to address education and policies for balanced nutrition intake.

• Bulletin of the Korean Chemical Society
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• v.19 no.5
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• pp.527-530
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• 1998

This paper presents the electrochemistry and molecular orbital (MO) picture of a series of conformationally-restricted thioxantone derivatives. A series of $C_2-substituted$ thioxanthones were examined to probe the electronic influence of the substituent on the electrooxidation and electroreduction sites (i.e., on the electron densities at the 10-and 9-positions), respectively. In the presence of "electrophoric" groups such as C=O and S, characteristic electrochemical reduction and oxidation responses are observed. The electrochemical reaction was diffusion-controlled, because the $I_p/{\upsilon}^{1/2}$ ratio was constant for the anodic and cathodic wave of thioxantone derivatives. These substituent effects are presented in terms of correlations of oxidation (or reduction) potentials with the highest occupied molecular orbital (HOMO), or lowest unoccupied molecular orbital (LUMO) energies, respectively. There is good correlation between energies of the HOMO vs. $E_{pa}^{(+)}$ and energies of the LUMO vs. $E_{pc}^{(-)}$. Frontier Molecular Orbital (FMO) is changed by the functional group of thioxanthones. FMO energy level was offered us the information about the electron transfer direction, and the coefficient of FMO was offered the information about the electron transfer position. Sulfur atom has an important effect on oxidation potential, $E_{pa}^{(+)}$ and the carbonyl carbon has an important effect on reduction potential, $E_{pc}^{(-)}$. Therefore we were appreciated that the contribution of sulfur atom for the $E_{pa}^{(+)}$ and HOMO energies is larger than the contribution of carbonyl group for the $E_{pc}^{(-)}$ and LUMO energies.

• Coupled systems mechanics
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• v.12 no.4
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• pp.391-407
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• 2023

This paper presents a static study of a rectangular functional graded material (FGM) plate, simply supported on its four edges, adopting a refined higher order theory that looks for, only,four unknowns,without taking into account any corrective factor of the deformation energy with the satisfaction of the zero shear stress conditions on the upper and lower faces of the plate. We will have determined the contribution of these stresses in the transverse deflection of the plate, as well as their effects on the axial stress within the interfaces between the layers(to avoid any problem of imperfections such as delamination) and on the top and bottom edges of the plate in order to take into account the fatigue phenomenon when choosing the distribution law of the properties used during the design of the plate. A numerical statement, in percentage, of the contribution of the shear effect is made in order to show the reliability of the adopted theory. We will also have demonstrated the need to add the shear effect when the aspect ratio is small or large. Code routines are programmed to obtain numerical results illustrating the validity of the model proposed in the theory compared to those available in the literature.

• Journal of the Korean Society of Food Culture
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• v.27 no.3
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• pp.240-250
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• 2012

This study was performed to investigate the consumption of coffee beverages and energy contribution ratios of coffee beverages and accompanying snacks by college students in Deajeon City and Chungnam Province in Korea. Questionnaire survey, dietary survey, and snack survey using food record method during 3-days were carried out. As a result, we found that 86.9% of male students and 75.6% of female students consumed coffee beverages usually, with no differences between the two groups. However, the frequency of coffee beverages consumed by female students out-numbered that of male students by 1 cup a day to 1-2 cups a week (p<0.05). Furthermore, male students most likely consumed coffee beverages at schools or academies, but female students consumed them at coffee shops (p<0.01). The reasons male students gave to consume coffee beverages were for scent, taste, fatigue, and to stay awake. Similarly, the reasons female students gave to consume coffee beverages were for scent, taste, habit, and to stay awake (p<0.01). Fully 58.1% of male students and 80.0% of female students ate snacks along with coffee beverages (p<0.01). Most male students substituted a coffee beverage and accompanying snack for a regular meal once a month. Female students were doing it at most 2-3 times a month (p<0.05). The mean daily dietary energy intake of male students was 1,924 kcal/d, and of female students was 1,518 kcal/d (p<0.001), which both were below the estimated energy requirements. Male students obtained 285.6 kcal/d and female students obtained 289.5 kcal/d from coffee beverages and accompanying snacks. There was a significant different in dietary intake of energy (p<0.05), calcium, and iron (p<0.001) for each ratio of reference intake between male and female students. The students who ate larger amounts of coffee beverages and accompanying snacks consumed less dietary energy, protein, calcium, and iron, respectively (p<0.05). These results show that many students consume coffee beverages regularly and obtain large amounts of energy from coffee beverages and accompanying snacks. It also shows that student's dietary nutrient intake tends to be poorer, as he or she obtains more energy from coffee beverages and accompanying snacks. Therefore, it is critical to monitor the influence of consumption of coffee beverages and accompanying snacks on the dietary nutrient intakes and health of college students, and to provide nutrition education about the proper consumption of coffee beverages and accompanying snacks based on scientific evidence.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.689-700
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• 1996

Fisheries products have to be produced and maintained by work processes from the environment, sometimes helped by people. In Korean fisheries both environmental production and its economic use are included within the windows of system approach. EMERGY is the sum of all inputs expressed as one form of solar energy required directly and indirectly to make a product. Calculating EMERGY flows into Korean fisheries evaluates the real wealth contributed by environmental production and its economic use. Several indices calculated from EMERGY analysis table and a three-arm diagram give perspective on the type and efficiency of the environmental uses. Net EMERGY yield ratio is a measure of its net contribution to the economy beyond its own operation. For adjacent waters fisheries in Korea, the net contribution to the economy is 11.85 or higher, which is a stimulus to the economy that is able to purchase it. EMERGY investment ratio measures the intensity of the economic development and the loading of the environment. The ratio for Korean fisheries as a whole is 0.50, for the adjacent waters fisheries 0.09 and for the shallow-sea cultures 1.28, which is lower than the same index for the industry of the developed country (7.0). The component of environment drawn into production are large compared to purchased investment in Korean fisheries. Much more EMERGY is contained in fisheries products than in the paid services used to process the products. The EMERGY exchange ratio for Korean fisheries as a whole is 6.98, for the adjacent waters fisheries is 10.69 and for the shallow-sea cultures is 1.25. Using market values to evaluate wealth of environment resources is found to be many times too small. Money is paid only to people for their contribution, and never to the environment for its contribution. Macroeconomic value is the appropriate measure for discussing large-scale considerations of an economy, including environment and human goods & services.

• Magazine of the Korean Society of Agricultural Engineers
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• v.34 no.3
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• pp.53-63
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• 1992

To investgate the fracture behavior of the steel fiber reinforced concreate, the specimens with different steel fiber contents of 0.0%, 0.5%, 1.0%, 1.5%, were made and notched with differents notch depth ratios of 0.0,0.2, 0.4, 0.6, and the three point bend tests were followed. Test results of 16 different types of above combined specimens were summarized as follows. 1.The load line deflection contents were found to increase 5%, 16%, 19%, respectively, compared to the unnotched specimen with the increased of initial notch depth ratio to 0.2,0.4, 0.6, respectively. 2.The frexural strength were found to decrease 14%, 16%, 21 %, respectively, compared to the unnotched specimen with the increase of initial notch depth ratio to 0.2, 0.4, 0.6,respectively. 3.The stress intensity factors of the steel fiber reinforced concrete were found to increase 1.1 1.5 1.9 times, respectively, compared to the concrete with no steel fiber content with the increase of fiber content to 0.5%, 1.0%, 1.5%, respectively. 4.The influence of the mass of the steel fiber reinforced concrete to the whole fracture energy was found to be minor with 6~8 % contribution. 5.The fracture energy of the steel fiber reinforced concrete, considering the load-deflection curve and concrete mass was found to be approximately 350-380kg m/m$^2$. 6.The regression analysis through the relationship between the compressive(Oc)/tensile (OT) strength and fracture energy(Gf) showed that the fracture energy of the steel fiber reinforced concrete could be predicted as follows. Gf= 19.2662 Oc - 3940.4 Gf= 246.876 OT- 6008.8

• Structural Engineering and Mechanics
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• v.9 no.3
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• pp.241-256
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• 2000

The major sources of energy dissipation in steel frames with partially restrained (PR) connections are evaluated. Available experimental results are used to verify the mathematical model used in this study. The verified model is then used to quantify the energy dissipation in PR connections due to hysteretic behavior, due to viscous damping and at plastic hinges if they are formed. Observations are made for two load conditions: a sinusoidal load applied at the top of the frame, and a sinusoidal ground acceleration applied at the base of the frame representing a seismic loading condition. This analytical study confirms the general behavior, observed during experimental investigations, that PR connections reduce the overall stiffness of frames, but add a major source of energy dissipation. As the connections become stiffer, the contribution of PR connections in dissipating energy becomes less significant. A connection with a T ratio (representing its stiffness) of at least 0.9 should not be considered as fully restrained as is commonly assumed, since the energy dissipation characteristics are different. The flexibility of PR connections alters the fundamental frequency of the frame. Depending on the situation, it may bring the frame closer to or further from the resonance condition. If the frame approaches the resonance condition, the effect of damping is expected to be very important. However, if the frame moves away from the resonance condition, the energy dissipation at the PR connections is expected to be significant with an increase in the deformation of the frame, particularly for low damping values. For low damping values, the dissipation of energy at plastic hinges is comparable to that due to viscous damping, and increases as the frame approaches failure. For the range of parameters considered in this study, the energy dissipations at the PR connections and at the plastic hinges are of the same order of magnitude. The study quantitatively confirms the general observations made in experimental investigations for steel frames with PR connections; however, proper consideration of the stiffness of PR connections and other dynamic properties is essential in predicting the dynamic behavior.

• Journal of Nutrition and Health
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• v.30 no.10
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• pp.1211-1218
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• 1997

This study was performed to assess the consumption of various seasonings (SNG), which are usually omitted from food frequency questionnaire(FFQ), and their contributions to nutrient intake levels. A dietary survey with FFQ , which surveyed the intake of 65 mainly uncooked food items, was conducted for 493 adults over 30 years of age from 373 households in a rural area of Korea. Household consumption of major SNG items-garlic , red pepper powder, fermented soy bean paste, oil, soy sauce , salt, etc- were estimated by a questionnaire completed by the housewives of the survey participants. The daily consumption of SNG items by each subject was determined by 3 methods ; dividing daily household consumption by \circled1 the number of household members. \circled2 the number of household members over 10 years of age and \circled3 the weighted number of houshold members calculated by the ratio of the RDA for energy. All three methods for calculating the daily personal consumption of seasoning gave similar results, which may have been partly due to the homogenity of family age distribution of the households in the study area. Therefore, the results of method \circled1 were used to determine the contribution of SNG to nutrient intake of subjects in this study. Daily intake of all nutrients were significantly increased by including SNG consumption in the measurements as compared to measuring intake by FFQ alone (p0.01). Percentages of total daily nutrient intake from SNG ranged from 2.3% in carbohydrate to 34.4% in fat. Nutrients with higher contributions from SNG were energy (8.4%), fat (34.4%), Fe(20.55) and $\beta$-carotene(17.9%). These results indicate that SNG consumption can contribute significantly to the intake of several nutrients and must be considered in surveys using FFQ.

• New & Renewable Energy
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• v.18 no.3
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• pp.1-9
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• 2022

This study analyzed the anticipated supply-and-demand of forest biomass energy (through wood pellets) until 2050, in South Korea. Comparing the utilization rates of forest resources of five countries (United Kingdom, Germany, Finland, Japan, and S. Korea), it was found that S. Korea does not nearly utilize its forest resources for energy purposes. The total demand for wood pellets in S. Korea (based on a power generation efficiency of 38%) was predicted to be 3,629 and 4,371 thousand tons in 2034 and 2050, respectively. The anticipated total wood pellet power generation ratio to target power consumption is 1.13% (5,745 GWh), 1.17% (6,336 GWh), and 1.25% (7,631 GWh) in 2020, 2030, and 2050, respectively. Low value-added forest residues left unattended in forests are called "Unused Forest Biomass" in S. Korea. From the analysis, the total annual potential amount of raw material, sustainably collectible amount, and available amount of wood pellet in 2050 were estimated to be 6,877, 4,814, and 3,370 thousand tons, respectively. The rate of contribution to Nationally Determined Contributions was up to 0.64%. Through this study, the authors found that forest biomass energy will contribute to a carbon neutral society in the near future at the national level.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.2
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• pp.92-97
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• 2008

Salt wedge into the river from the sea or fresh water flume (fresh wedge) in the ocean from the sea has density current characteristics. However, when temperature and salinity simultaneously determine the density of wedges, one of salinity and temperature can distributed in the reversed profiles against gravity, even though the density profile is stable. In this case, the double diffusive process is critical in determining mixing rate. The present work studies relative contribution of shear driven mechanical mixing component and double diffusive layering process, when warm salty denser water is introduced into the cold fresh lighter water column. Laboratory experiment releases warm salty denser water into cold fresh lighter water controlling discharge amount to achieve the steady state of density current. When longitudinal density rate becomes 15, the released amount ratio of salt and heat changes sharply and in the releasing point, vigorous mixing occurs with increase of discharged amount due to double diffusion. Double diffusion distabilizes gravitational stability and enhances the mixing rate up to $6{\times}10$ times at the lower density ratio comparing to the higher density ratio.