• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.2
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• pp.101-109
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• 2013

Recently, it is certain that the increase of heating and cooling energy consumption by radical change in climate condition has caused serious problems related to environmental and energy concerns associated with increase of fossil fuel usage and carbon dioxide production as well as global warming. So, various actions to reduce greenhouse gas exhaustion and energy consumption have been prepared by world developed countries. Our government has also been trying to seek energy control methods for houses and buildings by proclaiming political polices on low-carbon green growth and construction and performance standards for environment-friendly housing. The energy consumption by buildings approximately reaches 25% of total korea energy consumption, and the increasing rate of energy consumption by buildings is stiffer than the rate by the other industries. The greatest part in the buildings of the energy consumption is building facade. While lots of research projects for reducing energy consumption of the facade have been conducted, but a few research projects on concrete comprising more than 70% of outsider of buildings has been tried. This research presents here a study to improve the insulation property of structural concrete formed by micro form admixture (MFA) with experimentally reviewing the physical, mechanical and thermal characteristics of the concrete. As the results of this experiment, in the case of concrete mixed with MFA, slump loss has been improved. As the mixing ratio of MFA increases, the compressive strength is decreased and thermal conductivity is increased. Also it was found that water-cement ratio increases, the compressive strength is decreased and thermal conductivity is increased. but, there was not big influence by the change of fine aggregate ratio.

• Journal of the Korean Dietetic Association
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• v.7 no.3
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• pp.267-273
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• 2001

The purpose of this study was to investigate the relationship between alcohol consumption and nutritional status of university male freshman in Chungnam area. The total of 111 subjects took part in the study and, they were observed general characteristics, alcohol consumption status, and nutrient intake using questionnaires. The mean age, height, weight, and BMI of the subjects were 19.3 years, 174.3㎝, 65.2㎏, and 21.5㎏/$m^2$ respectively. The mean alcohol consumption, and energy intake from alcohol were 7.8g/day, 55.3kcal/day. A significant number of subjects(48.2%) answered their frequency of alcohol consumption was once 2 weeks. Only 4.6% of subjects answered never drink. In almost subjects, alcohol consumption have been stared since they were adolescents, and major type of alcoholic beverage was 'soju'. The mean energy intake was 1985.6kcal and, energy ratio from carbohydrate, protein, fat was 58 : 15 : 27. There were significantly positive correlation among alcohol consumption and, body weight(p<0.05), intake of food, (p<0.05), energy(p<0.001), animal fat(p<0.05), fiber(p<0.05), vitamin $B_2$(p<0.05) and niacin(p<0.05). The alcohol consumption period showed a significantly positive correlation with alcohol consumption per one time(p<0.05). In summary, high consumption of alcohol in subjects was observed. Also, increase of alcohol consumption was related to weight gain and nutritional imbalance. Therefore, it is need that nutrition education for prevention of high alcohol consumption in university freshman and adolescents.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.5 s.311
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• pp.1-7
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• 2006

This paper presents experimental instruction-level current consumption model for low power microcontroller ATmega128. The accessibility of instruction for internal memory decides power consumption of the microcontroller as much as 17% of difference between access instruction and non-access instruction. The power consumption for the given program will be increased in the proportional to the ratio of memory access instruction and lower level memory access in the hierarchy. Throughout the current consumption model, the power consumption can be predicted and optimized in the direction of reducing the frequency memory access. Also, the various optimization methods are introduced in terms of software and hardware viewpoints.

• Nutrition Research and Practice
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• v.16 no.2
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• pp.194-204
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• 2022

BACKGROUND/OBJECTIVES: Sugar-sweetened beverages (SSBs) are regarded as modifiable risk factors for mental health in several populations. Although the consumption of SSBs is steadily increasing in Korea, there is scant evidence regarding the impact of SSB consumption on depression and suicidal ideation. The aim of this study was to investigate the association of SSB consumption with depression and suicidal ideation among adults in Korea. SUBJECTS/METHODS: We used the data for 5,465 participants (2,170 men and 3,295 women) aged ≥ 20 years from the 2014 and 2016 Korea National Health and Nutrition Examination Survey. The subjects were divided into four groups according to SSB consumption using a food frequency questionnaire. Logistic regression analyses were conducted to examine the association of SSB consumption with depression and suicidal ideation, adjusting for sociodemographic, health behavior, and dietary variables. RESULTS: Participants consuming ≥ 1 SSB/day had a significantly higher risk of depression (odds ratio [OR], 1.54; 95% confidence interval [CI], 1.08-2.18; P < 0.001) and suicidal ideation (OR, 2.20; 95% CI, 1.13-4.28; P < 0.001) compared with those in the non-SSB group after adjusting for potential confounding factors. CONCLUSIONS: Our results suggest that SSB consumption is positively associated with depression and suicidal ideation in Korean adults.

• Journal of Nutrition and Health
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• v.46 no.2
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• pp.166-176
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• 2013

The purpose of this study was to investigate consumption of health functional food (HFF) and dietary habits, nutrient intake, and dietary quality by HFF consumption in college students. The subjects of this study included 283 college students (179 males and 104 females) in Incheon metropolitan city. The cross-sectional study was conducted using self-reported questionnaires, including kinds of HFF consumed, motivation for purchase, reason for consumption, effect after consumption, reason for no consumption, and dietary habits. A three-day recall method was used for dietary assessment. Dietary qualities were assessed using nutrient adequacy ratio (NAR), mean adequacy ratio (MAR), and nutrient density (ND) values. The percentage of HFF consumption was 40.2% in males and 50.0% in females. The main kinds of HFF consumed by males were vitamins and minerals, red ginseng, protein, and omega-3 fatty acid, in that order. HFF consumed by females were vitamins and minerals, red ginseng, omega-3 fatty acid, and individually approved functional ingredients, in that order. The main motivation for purchase of HFF was recommendation of family and relatives (males 76.4% and females 78.8%). The main reason for consumption of HFF was health promotion (males 67.7% and females 63.5%) and the main reason for no consumption of HFF was not having a health problem (males 49.5% and females 46.2%). The dietary habit score for 'eat the milk or dairy product everyday' (p < 0.05) in females was significantly higher in HFF consumers, compared to HFF non-consumers. In males, the ND of vitamin B1 (p < 0.05) in HFF consumers was significantly higher compared to HFF non-consumers. In females, HFF consumers showed a significantly higher ND of vitamin B2 (p < 0.05) and Ca (p < 0.01), compared to HFF non-consumers. Regardless of HFF consumption, the NAR of vitamin C, folic acid, and Ca was less than 0.7. These results suggest the need for nutrition education for college students in order to improve dietary habits and for balanced nutritional status, and to provide correct information on HFF.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.1
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• pp.82-88
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• 2011

Lean combustion and exhaust emission characteristics in a ethanol fueled spark-ignited engine according to ethanol-gasoline fuel blending ratio were investigated. The test engine was $1591cm^3$ and 10.5 of compression ratio SI engine with 4 cylinders. In addition, lambda sensor system was connected with universal ECU to control the lambda value which is varied from 1.0 to 1.5. The engine performance and lean combustion characteristics such as brake torque, cylinder pressure and rate of heat release were investigated according to ethanol-gasoline fuel blending ratio. Furthermore, the exhaust emissions such as carbon monoxide (CO), unburned hydrocarbon (HC), nitrogen oxides ($NO_x$) and carbon dioxide ($CO_2$) were measured by emission analyzers. The results showed that the brake torque, cylinder pressure and the stability of engine operation were increased as ethanol blending ratio is increased. Brake specific fuel consumption (BSFC) was increased in higher ethanol blending ratio while brake specific energy consumption (BSEC) was decreased in higher ethanol blending ratio. The exhaust emissions were decreased as ethanol blending ratio is increased under overall experimental conditions, however, some specific exhaust emission characteristics were mainly influenced by lambda value and ethanol-gasoline fuel blending ratio.

• Structural Engineering and Mechanics
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• v.55 no.3
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• pp.555-581
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• 2015

Triangular pyramid and Quadrangular pyramid elements for partial double-layer spherical reticulated shells of pyramidal system are investigated in the present study. Macro programs for six typical partial double-layer spherical reticulated shells of pyramidal system are compiled by using the ANSYS Parametric Design Language (APDL). Internal force analysis of six spherical reticulated shells is carried out. Distribution regularity of the stress and displacement are studied. A shape optimization program is proposed by adopting the sequence two-stage algorithm (RDQA) in FORTRAN environment based on the characteristics of partial double-layer spherical reticulated shells of pyramidal system and the ideas of discrete variable optimization design. Shape optimization is achieved by considering the objective function of the minimum total steel consumption, global and locality constraints. The shape optimization of six spherical reticulated shells is calculated with the span of 30m~120m and rise to span ratio of 1/7~1/3. The variations of the total steel consumption along with the span and rise to span ratio are discussed with contrast to the results of shape optimization. The optimal combination of main design parameters for six spherical reticulated shells is investigated, i.e., the number of the optimal grids. The results show that: (1) The Kiewitt and Geodesic partial double-layer spherical reticulated shells of triangular pyramidal system should be preferentially adopted in large and medium-span structures. The range of rise to span ratio is from 1/6 to 1/5. (2) The Ribbed and Schwedler partial double-layer spherical reticulated shells of quadrangular pyramidal system should be preferentially adopted in small-span structures. The rise to span ratio should be 1/4. (3) Grids of the six spherical reticulated shells can be optimized after shape optimization and the total steel consumption is optimized to be the least.

• Korean Journal of Community Nutrition
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• v.8 no.3
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• pp.280-287
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• 2003

To investigate effects of the shared living on nutrient intakes,250 college male students who were living alone (104 men) or sharing accommodation with friends (134 men) were participated. Their average age was 22.6 years, their average height was 171.8 cm, their average weight was 65.6 kg and their average Body Mass Index (BMI) was 22.2. The caloric intakes of the men living alone or sharing accommodation were 55.9% and 72.5% of the Korean Recommended Dietary Allowance (RDA), respectively. The decreased caloric level of the group living alone seemed to be due to their decreased protein and fat consumption as compared to that of the group sharing accommodation. The group living alone consumed increased amounts of fiber for breakfast and half the carbohydrates, but more fat (p < 0.05) in snacks than the group sharing accommodation. The daily carbohydrate : protein : fat (C : P : F) ratio averaged 58.6 14.1 27.3, which is a lower carbohydrate and a higher fat ratio than the Korean recommended ratio. However, the group living alone was closer to the Korean recommended ratio than the group sharing accommodation. The food intake habits were evaluated as being poorer in the group living alone as compared to the group sharing accommodation, less frequent consumption of fried / pan-fried dishes, and fruits / juices, but more frequent consumption of instant / processed foods. In comparing the eating patterns of the two groups, the group living alone showed better eating habits, such as more“breakfast eating”and less“snacking in the morning, afternoon or late at night”whereas the group sharing accommodation showed better eating habits such as less“picky eaters”and less “eating out”. In the group living alone, their lower caloric intake was assumably due to their fewer side dishes, however they showed higher eating frequencies of instant i processed foods. Since the lifestyle of living alone seems to grow gradually among young men, we strongly recommend dietary education for them.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.10
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• pp.837-844
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• 2014

Automotive manufacturers have recently developed various technologies for improving fuel economy and satisfying enhanced emission regulations. The ultra-lean direct injection engine is a promising technology because it has the advantage of improving thermal efficiency through the deliberate control of ignition. A conventional LPG engine has been redesigned to an ultra-lean-burn LPG direct injection engine in order to adopt combustion system of ultra-lean-burn. This study is aimed at investigating the effect of a change in the compression ratio on the performance and emission characteristics of a lean-burn LPG engine. The fuel consumption, heat release rate, combustion pressure, and emission characteristics are estimated depending on changing the effect of compression ratio. When the compression ratio is increased, it is difficult to improve the fuel consumption owing to an unstable combustion state, but the total hydrocarbon and nitrogen oxide emissions are reduced.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1B
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• pp.113-118
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• 2006

Cost estimation of an intermittent aerobic digestion technology was carried out in this study. Aeration ratio is one of the most important design factors and it affects installation and power consumption cost. For the purpose, digestion efficiency was fixed at 35% of SS reduction and the reactor type was assumed a 2-chamber sequencing batch reactor (SBR). Installation cost and power consumption cost were evaluated and converted in terms of present value that could reflect the rate of discount and the rate of economic growth. The lower aeration ratio needs higher installation cost but lower power consumption cost. From the point of only installation cost, conventional aerobic digestion is cheaper than intermittent aerobic digestion. But intermittent aerobic digestion is better economical for more than 10 years of estimated service life. The optimal aeration ratio was dependent on the service life and it was lower as the estimated service life increased. For the 45 years as the service life, the optimal aeration ratio was estimated 0.3 and the total cost was 64% of the conventional aerobic digestion.