• Economic and Environmental Geology
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• v.23 no.3
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• pp.309-322
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• 1990

The accelerated industrialization of Korean economy over the last couple of decades has brought an era of mass consumption of mineral commodities. This increased consumption has been satisfied mainly by imports from abroad. South Korea has about 50 useful mineral commodities for the mineral industry, among 330 kinds of minerals described. In 1988 the self-sufficiency ratio of domestic demand for 44 non-fuel(metallic and non-metallic) minerals as a whole was no more than 29 percent. The ratio for 26 non-metallic minerals was much higher, about 66 percent. On the other hand, the ratio for 18 metallic minerals was relatively very low, about 6.3 percent. The correlation between GNP and mineral consumption in South Korea shows well the slow down patterns during the last two decades.

• Korean Journal of Community Nutrition
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• v.6 no.2
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• pp.162-171
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• 2001

This study was performed to investigate the relationship between obesity, health-related lifestyle, and dietary intake and serum lipid level in 96 male university students. Health-related lifestyle factors were obtained from questionnaires. Dietary intakes were evaluated with one-day 24-hr recall and two-day dietary record. Anthoropometric data were recorded and serum cholesterol and triacylglycerol concentrations were measured. 21.9%, 36.5%, 36.5%, and 6.2% of the subjects had levels beyond the normal range in serum total cholesterol(TC), HDL-cholesterol(HDL-C), LDL-cholesterol(LDL-C), and triacyglycerol respectively, and 57.3% of the subjects had more than one hyperlipidemic factor. TC was correlated positively with BMI(p〈0.01), waist length(p〈0.05), hip length(p〈0.05), and the amount of smoking(p〈0.05). HDL-C was correlated negatively with BMI(p〈0.05) and hip lenghth(p〈0.05). LTD-C was correlated positively with BMI(p〈0.01), water length(p〈0.05), hip length(p〈0.01), and coffee consumption(p〈0.05). TG was correlated positively with waist length(p〈0.01), waist-to-hip ratio(p〈0.05), and amount of smoking(p〈0.01) and negatively correlated with frequence of exercise(p〈0.05). Among nutrient intakes, only the ratio of protein to energy was correlated negatively with TC(p〈0.05). Logistic regression analysis revealed that BMI, waist length, hip length, waist-to-hip ratio, and amount of cigarette smoking were associated with an increased risk of hyper-TC. BMI, waist length, and hip length were associated with an increased risk of hypo-HDL-C. BMI and coffee consumption were associated with an increased risk of hyper-LDL-C. Amount of cigarette smoking was associated with an increased risk of hyper-TG. In conclusion, a high prevalence of hyperlipidemia in subjects was observed. Also obesity, smoking, and coffee consumption were observed to be highly with the risk of hyperlipidemia in subjects. These findings imply that these factors should be primarily considered in planing the nutrition education program for the prevention of cardiovascular disease in male university students.

• Journal of Nutrition and Health
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• v.29 no.5
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• pp.499-506
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• 1996

It has been established that hypercholesterolemia is a major risk factor for atherosclerosis. Recent data showed that the incidence of hypercholesterolemia increase in Korea. n-3 Fatty acids lower serum triglyceride profoundly but the effect on serum cholesterol is not clear. This study was performed to assess the effects of low and moderate supplementation of marine n-3 fatty fish on serum cholesterol in young healthy korean woman. Nineteen subjects were divided into two groups. Each group receive an experimental diet supplemented with either 100g (group I) or 200g mackeral(Scomber japonicus) fish(group II) for 1-week. The diet was designed to avoid in which the amount of n-6 fatty acids would be much greater than that of n-3 fatty acids. MUFA, SFA intakes were similar in the two diets. The ratio of n-6/n-3 fatty acids was 1 : 1.l for group I, 1 : 2.51 for group II. The average daily n-3 fatty acids consumption from fish was 3.87g/day (1.03g EPA, 2.84g DHA)for group I, 7.74g/day (2.06g EPA, 5.68g DHA) for group II. Blood samples were obtained 2 times before experimental diet, immediately after experimental diet for 1-week. After experimental diet for 1-week, the serum total-cholesterol levels decreased significantly (16.4$\pm$15.1mg/dl, p<0.01) in group II and lowered slightly (13.7$\pm$25.8mg/dl)in group I. There were no significant changes from baseline to the end of the study in serum HDL-cholesteol, LDL-cholesterol, HDL-C/T-C ratio, and LDC-C/HDL-C ratio. The results suggest that the moderate levels of marine n-3 fatty fish consumption could improve serum cholesterol in normal subjects, therefore in might be of value in the prevention of atherosclerosis. However the clinical usefulness of moderate n-3 fatty fish consumption of hypercholesterolemic subjects will require further study. Also further studies are required to elucidate the long-term effects of low n-3 fatty fish consumtion.

• Journal of Korean Society of Forest Science
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• v.50 no.1
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• pp.16-24
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• 1980

The purpose of this study is to analyse the demand-supply structure and its trend of the paper production in Korea. The ratio of paper was calculated to analyse the demand-supply structure. The cross-section and the time series analysis were adopted to analyse the demand-supply trend. The results obtained are summarized as follows: 1. In consumption ratio of paper the board paper was the highest, in export ratio the print paper was the highest. 2. In 1979, the consumption of paper was 45kg/capita, which were very high value comparing with the level of gross national products in Korea. 3. The elasticity of income and price in paper consumption per capita was 1.67 and -0.73, respectively. The more the GNP increases, the more the industrial paper demand rises rapidly.

• Korean Journal of Community Nutrition
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• v.4 no.3
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• pp.394-402
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• 1999

The purpose of this study is to investigate diet quality and changes in nutrient and food intake with increase in age. Subjects were 69 patients(28 males, 41 females) living in Jeon-ju city, over middle-aged, and they were the same patients studied 4-7 years ago in a previous study. Dietary survey with one day 24-hour recall method was used. Energy, calcium, vitamin A and vitamin B$_2$intakes were lower than the RDA and vitamin C was in excessive status in pre-test and post-test. In food groups examrned, the consumption of potatoes, beans, vegetables, seaweeds, beverages, seasonings, oils, fish & shells and milks was increased amount than 4-7 years before but the consumption of cereals(p<0.01), sugars, seeds, fruits, processed food, meats and eggs was decreased. Diet quality was assessed by %RDA, nutrient adequacy ratio(NAR), mean adequacy ratio(MAR), dietary diversity score(DDS), meal balance and food group pattern. In %RDA, those proportion of appropriate intake in post-test in were higher than those in pre-test. For most nutrient except vitamin A, the levels of NAR in post-test were higher than in pretest. The MAR, an index of overall dietary quality, was 0.77 for pre-test and 0.83 for post-test(p<0.05). When we counted the major food groups consumed(KDDS), 62.3% of subjects had a KDDS of 3 in pre-test and 42.0% of subjects had a KDDS of 4 in post-test. Based on these results, in terms of variety and balance, total diet quality was improved with advancing of age.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.3
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• pp.551-558
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• 2004

Recently, fuel prices have been continually raised in diesel engine. Such a change in the fuel price influences enormously the development trend of marine diesel engines for slow speed, In other words, the focus was shifted from large diameter and high speed to low fuel consumption. Accordingly, more efforts are being made for engine manufacturing and development to develop highly efficient engines. In this study. a single cylinder 4 stroke cycle DI slow speed diesel engine was designed and manufactured, a 4 stroke cycle was configured and basic performances were evaluated. The results are as follows. The optimal fuel injection timing had the lowest value when specific fuel consumption was in BTDC 8~$10^{\circ}$, a little more delayed compared to high speed diesel engines. Cycle variation of engines showed about 5% difference at full loads. This is a significantly small value compared to the cycle variation in which stable operation is possible, showing the high stability of engine operation is good. The torque and brake thermal efficiency of engine increased with an increase of engine 250-450 rpm. but fuel consumption ratio increased from the 450 rpm zone and thermal efficiency abruptly decreased. Mechanical efficiency was maximally 70% at a 400 rpm that was lower than normal engines according to the increase of mechanical frictional loss for cross head part. The purpose of this study was to get more practical engines by comparing the above results with those of slow speed 2 stroke cycle diesel engines.

• Korean Journal of Exercise Nutrition
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• v.16 no.2
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• pp.113-122
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• 2012

This study assessed the amount of energy consumed and fat deposition after endurance training in order to review the effect of 4-week endurance exercise on resting metabolic rate of a mouse during and after exercise and the effect of exercise. A total of 19 seven-week-old ICR male mice were used as the study subject. Those mice were divided into sedentary group (Sed) and trained group (Tr) after a week of environment adaption. The Tr group was trained with endurance exercise five times a week for four weeks. Weight and the amount of food intake were daily weighed and resting metabolic rate and metabolic rate after exercise were assessed before starting exercise and on the fourth week after training. Metabolic rate during exercise were measured four weeks after training. At the end of breeding period, statistically significant difference was shown in weights of trained and sedentary groups (p < 0.05). During a resting period, no significant difference was shown in oxygen intake, respiratory exchange ratio, and the amount of carbohydrate and fat oxidized. Moreover, no significant difference was shown in excess post-exercise oxygen consumption (EPOC) of an hour period after training. In contrast, the maximal oxygen uptake (VO₂ max) was approximately 11.1% higher in trained group after training compare to before. However, there was no significant difference in respiratory exchange ratio and carbohydrate and fat oxidization. During exercise, oxygen uptake, carbon dioxide production, and respiratory exchange ratio in energy metabolism during exercise showed no significant difference. However, significant difference was exhibited in the amount of fat oxidized in both groups. Summing up those results, endurance exercise could be concluded to be effective in weight control. However, weight loss is thought to be resulted from increase in fat oxidization during exercise unlike the conclusion made from previous studies where weight loss is prominently influenced by energy metabolism during a resting period and increased fat oxidation during post-exercise recovery. All experimental procedures were carried out at the Animal Experiment Research Center of Konkuk University. This study was conducted in accordance with the ethical guidelines of the Konkuk University Institutional Animal Care and Use Committee.

• Nutrition Research and Practice
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• v.6 no.3
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• pp.254-262
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• 2012

The objective of this study was to provide information regarding trends of rice consumption of Korean adults based on different meal types. Respondent reports 24-hour recall data from the Korean National Health and Nutrition Examination Survey were used to assess daily rice consumption and intake ratios of rice for different meal types and places of preparation. Rice intake had gradually decreased from 224.6 g in 1998 to 190 g in 2001 and to 179.4 g in 2005. The rice consumption of Korean adults decreased every year in all ages for all places of meal preparation in 2001 and 2005 compare to 1998. Analysis for each meal type showed that rice intake at breakfast had not considerably changed, but rice intake had decreased at lunch and dinner. While the rice consumption ratio at lunch and dinner decreased, it also decreased or did not change at snack times except for the 19-29 age groups. All the age groups revealed comparable change in the analysis for meal types. There was some diversity between all age divisions in daily rice intake depending on place of meal preparation. The rice consumption by place of meal preparation was generally highest at home, lowest at other places, but it decreased in all places. The rice consumption at home was highest in the over 50 age group, lowest in the 20-30 age group. These changes seem to be related to food intake patterns of rice and substitutional foods in the diets and development regarding socio-economic status. So the need for further study on differences in rice intake based on socioeconomic levels and age group are indicated.

• Journal of the Korean Society of School Health
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• v.30 no.1
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• pp.48-58
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• 2017

Purpose: The purpose of this study was to identify the factors associated with energy drink consumption in Korean high school students. Methods: This cross sectional study used the secondary data from the 2015 Adolescent Health Behavior Online Survey. A total of 33,744 high school students were included in the study. Energy drink consumption was measured by asking how often they consumed energy drink during the previous week. Associated factors were categorized into socio-demographic characteristics, psychological characteristics, and health related behavioral characteristics. Complex samples logistic regression was used to analyze the influence of associated factors on energy drink consumption. Results: For socio-demographic characteristics, adolescent boys were likely to consume more energy drink than adolescent girls (Adjusted Odds Ratio [AOR]: 1.351, 95% Confidence Interval [CI]: 1.209~1.510). For psychological characteristics, depressed adolescents were likely to consume more energy drink than their counterparts (AOR: 1.697, 95% CI: 1.537~1.874). For health related behavioral characteristics, cigarette smoking (AOR: 1.336, 95% CI: 1.168~1.528), alcohol drinking (AOR: 1.126, 95% CI: 1.012~1.254), soda drink consumption (AOR: 1.800, 95% CI: 1.565~2.071), sweet drink consumption (AOR: 1.715, 95% CI: 1.431~2.054), and insufficient sleep time a day (AOR: 1.307, 95% CI: 1.197~1.427) were associated with energy drink consumption. Conclusions: In conclusion, energy drink consumption in Korean high school students were associated with such factors as psychological factors (depression) and health related behavioral characteristics (smoking, alcohol, sleep, soda and sweet drink). Thus, intervention programs in schools and communities should focus on these psychological and health related behavioral characteristics.

• Nutrition Research and Practice
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• v.17 no.4
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• pp.789-802
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• 2023

BACKGROUND/OBJECTIVES: Habitual coffee consumption was inversely associated with type 2 diabetes (T2D) and hyperglycemia in observational studies, but the causality of the association remains uncertain. This study tested a causal association of genetically predicted coffee consumption with T2D using the Mendelian randomization (MR) method. SUBJECTS/METHODS: We used five single-nucleotide polymorphisms (SNPs) as instrumental variables (IVs) associated with habitual coffee consumption in a previous genome-wide association study among Koreans. We analyzed the associations between IVs and T2D, fasting blood glucose (FBG), 2h-postprandial glucose (2h-PG), and glycated haemoglobin (HbA1C) levels. The MR results were further evaluated by standard sensitivity tests for possible pleiotropism. RESULTS: MR analysis revealed that increased genetically predicted coffee consumption was associated with a reduced prevalence of T2D; ORs per one-unit increment of log-transformed cup per day of coffee consumption ranged from 0.75 (0.62-0.90) for the weighted mode-based method to 0.79 (0.62-0.99) for Wald ratio estimator. We also used the inverse-variance-weighted method, weighted median-based method, MR-Egger method, and MR-PRESSO method. Similarly, genetically predicted coffee consumption was inversely associated with FBG and 2h-PG levels but not with HbA1c. Sensitivity measures gave similar results without evidence of pleiotropy. CONCLUSIONS: A genetic predisposition to habitual coffee consumption was inversely associated with T2D prevalence and lower levels of FBG and 2h-PG profiles. Our study warrants further exploration.