• Journal of the Korean Wood Science and Technology
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• v.13 no.3
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• pp.49-53
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• 1985

The effects of pre-treatments, the hot water extraction of wood meal and the addition of chemical ($CaCl_2$) to wood-cement water system on the properties of wood-cement composite such as modulus of rupture (MOR), modulus of elasticity (MOE), water sorption ratio and swelling ratio of resulting boards were studied in this experiment. The wood meals through 0.83mm(20 mesh) and retained on 0.42mm(35 mesh) screen were prepared from Pinus densiflora S. at Z. and Larix leptolepsis G. For hot water extraction, 500 grams of wood meal for each species were heated to boiling with 1,500ml of distilled water in 2-liter beaker for 6 hours. Every 2 hours, the wood meals were washed with boiling distil1ed water and reheated to boiling again. After 6 hours boiling, the boiled wood particles were collected by pouring this particles on 200 mesh screen. The collected particles then washed twice with hot distilled water and dried for 24 hours in an oven at $109{\pm}20^{\circ}C$. A mixture of 663.4 grams of cement with 331.7 grams of wood meal based on oven-dry weight were dry-mixed in a plastic vessel. The mixture was kneaded with 497.6ml of distilled water in the ratio of 1.5ml of water to a gram of wood meal. To add calcium chloride to the mixture as an accelerator, $CaCl_2$ 4% solution by weight per volume, was added to pine-or larch-cement board in the ratio of 3% to cement weight. To set wood-cement board, this mixture was clamped at 30cm ${\times}$ 30cm, in thickness of 1.5cm for 3 days at room temperature, declamped and then placed at open condition for 17 days. The target density was 1.0. The four specimens sized to 5cm in width and 28cm in length were used for MOR and MOE test for each treatment. After MOR test, the tested specimens were cut to the size of 5cm ${\times}$ 5cm for water sorption and swelling test. The twenty specimens used to measure the water sorption ratio (soaking 24 hours) and ten of these were used for swelling ratio measurement The results obtained were as follows: 1) Larch was not suitable for wood-cement boards because larch-cement board developed no strength, but pine showed 97.9kg/$cm^2$ by hot water extraction. 2) To increase MOR, hot water extraction was more effective than the addition of $CaCl_2$ in pine and larch because the $CaCl_2$ addition was seemed to speed up the ratio of cement hydration without reacting with the wood substances. 3) The water sorption ratio was lowered by the addition of $CaCl_2$ to wood-cement system because the chemical additive accelerated the rate of cement hydration. 4) In pine-cement board, the swelling ratio from 0.37 to 0.42 percent was observed in length and the swelling ratio from 0.88 to 2.0 percent in thickness. As a rule, the swelling ratio of wood-cement board was very low and the swelling ratio in thickness was higher than in length.

• Korean Journal of Health Education and Promotion
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• v.13 no.2
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• pp.69-96
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• 1996

This study was conducted to investigate the awareness and practice level of health food intake and use the information for the development of Public Health Policy and Health Education Program in order to help healthy dietary life. The interview was done by trained surveyors on 1, 143 city dwellers who were selected randomly from Oct. 2, to Oct. 21, 1992. The results are summarized as follows: 1) General characteristics of subjects; Among 1, 143 respondents, there were more female(53.8%) than males(46.2%) and the age group of 20-29 account for the hightest portion, 46.7%. As for the education levels, 45.3% of the subjects were college graduates. And 38.9% of the subjects were students. 2) The percentage of subjects who assess themselves ‘Healthy’ was 46.7% and ‘Not Healthy’ was 17.4%. 3) The subjects who have irregular meals(3 times a day) was 48.7%, the rate of females was higher than males. The proportion of unmarried subjects, people with low economic level, high education level, and students was high. 4) As for the amount of 1 meal, 72.4% was ‘moderate’, 16.3% was ‘too much’ amount, which was higher in 19 years old, single, low economic level, elementary school graduate, than other groups. 5) As for the eating speed, 40.2% was fast, which was higher in single(44.3%), in low economic level(50.0%). college graduate(44.9%), student(44.7%) than other groups. 6) As for the level of preference to hot and salty food, 25.7% preferred to have hot and salty food. The difference in the degree of preference to hot and salty food by age and economic level was significant. 7) With regard to the individual food taste, the subjects who prefer to meat and fried food were 12.3%. Which was higher in the group under 19 years old, single, and college graduates. 8) With regard to having a snack, 38.7% have a snack. By characteristics, the subjects who have a snack were higher in female, under 19 years old, single, high economic level, apartment dwellers, college graduate, and student than other groups. 9) As for the coffee intake amount per day, 39.8% of subjects was more than 3 cups daily. 10) With regard to the self-assessment of body weight, the subjects who assess themselves over body weight had late dinner time. 11) As for the correlation among related variables, the age and taking breakfast was positive correlation. And sex and drinking alcohol was positively associated while age had negative correlation.

• Journal of Nutrition and Health
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• v.41 no.2
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• pp.165-173
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• 2008

This study was intended to investigate whether the computer use hours affect physical development, dietary habits, and nutritional status or not. One hundred and ninety elementary school students from Gyeonggi province and Seoul were selected and surveyed during December, 2006. Participants were divided into 2 groups: long-time computer user (${\geq}$ 2 hrs./day) and short-time computer user (<2hrs./day). The survey included the questionnaires and anthropometric measurement. A dietary survey was conducted by using 24-hour recall method. The most of long-time computer user accessed computer more often than those of short-time computer user weekly bases. The purpose of the computer use was for the computer game (p < 0.05). Most participants accessed computer after the school at night and at their home. The longer the computer use, the more the body weight and %RBW (p < 0.05). Dietary habits score of long-time computer user 34.5 points) was lower than that of short-time computer user (38.0 points) (p < 0.001). The long-time computer user consumed more fatty foods, instant foods, and sugary foods. In case of dietary habit changes incurred by computer use, the long-time computer user had inferior dietary habits: skipping meals, meal size, appetite, eating speed, weight, exercise, and sleeping trouble (p < 0.05). The long-time computer user consumed less calories than the short-time computer user (p < 0.05). Also, the long-time computer user tended to have lower intakes of vitamin C, Ca, and dietary fiber without significance. From the findings, the longer use of computer by the elementary school children negatively affects their physical development, dietary habits and nutritional status.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.265-274
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• 2013

The purpose of this study was to investigate the dietary habits of the relevant factors according to the obesity status of children and adolescents. Services research studies conducted in the Ministry of Health, Welfare and Family Affairs of the '2009 Children and Youth Online Games and Family Activity Survey findings utilizing data. Study, the subjects utilized 9,462 elementary school students 2,778 people, 3,385 middle school students, high school students a total of 3,299 people were enrolled in the study. Were grouped according to the BMI of the study subjects. After dinner snack intake 18.5>BMI groups disagree 38.8%, 18.5${\leq}$BMI<23.0 group it was 41.1%, 23.5${\leq}$BMI<25.0 group it was 40.1%, $25{\leq}BMI$ groups disagree 37.4% response was highest(p=0.001). Investigate whether regular exercise every day, results showed that a high BMI index groups do not exercise more. Aggressiveness in time, such as physical education, the survey showed that a low BMI index group more likely to exercise vigorously. BMI index group of people around you and the speed of eating more meals were faster. If you let more to allow time to practice proper education of children and youth, health and enrich lives of the appropriation will be able to Services to live a healthy and happy life than to correct perceptions and lifestyles of children and adolescents. To do this, there is a need to educate parents, children and youth, as well as.

• Journal of Nutrition and Health
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• v.45 no.4
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• pp.336-346
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• 2012

This study was carried out to obtain information related to life styles, nutrition knowledge, and dietary habits according to gender and weight status of college students in Ulsan. The subjects were 324 college students (144 males, 180 females), and they were divided into three groups based on BMI. The average BMI was $21.0kg/m^2$, and the BMI of underweight, normal, and overweight students were 15.4%, 63.0%, and 21.6%, respectively. Among the male students, 0.1% and 34.0%, and among the female subjects, 27.2% and 11.7%, were included in the underweight and overweight groups, respectively. For dietary habits, the rate of skipping breakfast (34.9%) was considerably higher than those skipping lunch and dinner. Overall, the nutrition knowledge score, which was assessed by 15 questions, was somewhat low (44.9/100), yet, it was higher in females than in male students. There were significant differences among gender and weight status in several items of dietary habits such as the speed of eating meals, consuming breakfast on a regular basis, and sleeping hours. 40% of the subjects had appropriate knowledge about high calorie foods with low nutritional value. In the blood analysis of the subjects, males had higher hemoglobin levels than females. Further, more females were included in the risk group of Hb, total cholesterol, and LDL. These results suggest that in order to develop nutrition education programs for college students, differences between gender and weight status, dietary habits, and nutrition knowledge level should be considered.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.3
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• pp.459-470
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• 2014

This study investigated the correlation between eating behavior patterns, including eating-habits, food preferences, snack intake levels, and eating-out frequency and stress levels in high school students (males 174 and females 122) in Seoul. Analysis of eating-habits showed that eating-irregularity and eating-speed increased with elevated stress levels in both males and females under stress. The size of meals decreased in males, whereas it increased in females under getting stress (P<0.01). Preferences for sugar, hamburgers, and pizza also increased in both males and females under stress. Eating-out frequency decreased in males with a high stress level (P<0.01), whereas it increased in females. As for eating-out partners, males did not show any changes, whereas females preferred friends to family when under stress. Eating-out expenses also increased in both males and females, particularly in females with a high stress level (P<0.05). Males under increased stress showed effective stress reduction by increasing food intake, whereas females under increased stress showed less effective results. Consequently, high school students under high stress, particularly females, showed negative changes in eating behavior patterns, including irregular eating-habits, increased instant food and snack intakes, and increased frequency of eating-out. Therefore, development of appropriate programs for reducing stress and persistent nutrition education to promote good dietary behaviors are required.

• Journal of Nutrition and Health
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• v.44 no.6
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• pp.537-550
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• 2011

This study was conducted to identify behavioral characteristics of salty food intake according to saline sensitivity of adults living in a rural area. Anthropometry and blood pressure were measured and salt intake-related dietary behavior was surveyed by questionnaires through interviews with 402 subjects aged ${\geq}$ 40 years in Chungcheongbuk-Do, Korea. The percentages of overweight and obese among the subjects were 37.8% and 3.8% respectively. Mean blood pressure of the subjects was in the normal range, but the distribution of subjects who were normotensive, high normal, and hypertensive was 48.7%, 17.7%, and 33.6% respectively. Approximately 27% of all subjects habitually consumed salty food, which was the smallest group, followed by 38.1% normal and 35.1% not-salty food. However, 34.6% of the eldest group of ${\geq}$ 65 years consumed salty food. The saline insensitive group showed a higher percentage of irregular meals, overeating, speed-eating, an unbalanced diet, a preference for fried food, and habitual intake of salty foods. These subjects recognized the risk for eating salty food, but they lacked the will to reduce their salty food intake. Compared to spouses and family members, experts such as doctors, nurses, and dieticians were the most influential for reducing the salty food intake of subjects. Saline sensitive group had relatively better control over salty food intake at every meal, eating out, and even when eating salty food that the spouse preferred. The saline sensitive group ate more frequently vegetables and fruits, whereas the saline insensitive group ate more frequently hot spicy foods. In conclusion, the results suggest that it is necessary to establish a social atmosphere toward reducing salt intake at the level of the government and food industry and to set action plans to be available for nutrition education programs to reduce salt intake nationwide.