• Journal of the Korean Society of Food Science and Nutrition
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• v.11 no.3
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• pp.15-19
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• 1982

The Changes of nitrate and nitrite contents at different storage temperatures (low tempenature : $4{\sim}7^{\circ}C$, high temperature: $28{\sim}30^{\circ}C$) were studied in relation to the viable bacterial population. The contents of nitrate and nitrite in milk were 1. 10 ppm and 0.03 ppm, respectively. When milk was storaged for 7 days at $28{\sim}30^{\circ}C$, nitrate concentration decreased to 0.3 to 0.6 ppm, whereas nitrite increased up to 0.13 to 0.08 ppm. However, during the storage at $4{\sim}7^{\circ}C$, their contents were little changed. The number of viable bacterial population in raw milk appeared $9{\times}10^6/ml$, and rapidly increased throughout 3 days storage at high temperature, but afterward it tended to decrease. This seemd to indicate that nitrate was reduced to nitrite by the nitrate reducing bacteia in milk, and the changes in the viable bacterial population were also related to the changes of pH and titratable acidity.

• Journal of the Korean earth science society
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• v.23 no.3
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• pp.280-293
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• 2002

In this study, we analyzed the long-term distribution patterns of $CH_4$ determined from the Moo-Ahn (MAN) observatory in relation with those derived from the world major background monitoring sites. Comparison of the data were made using those data sets collected for the period between Aug. 1995 to Dec. 1991. The mean $CH_4$ concentration of MAN observatory was measured to be 1898${\pm}$85.3 ppb, recording the highest concentration of all the monitoring sites. When the concentration of $CH_4$ for different stations was compared over latitudinal scale, its concentration appeared to increase systematically as a function of latitude with an exception of MAN (and the other Korean monitoring site at Tae Ahn). Moreover, such phenomenon was more distinctive in Northern than Southern Hemisphere. According to the analysis of the monthly distribution patterns of $CH_4$ at MAN observatory, its concentration level began to increase from the months of February/March and peaked during August. In addition, when the level of oscillation in monthly concentrations (between the maximum and minimum values) was checked, differences were significant between MAN and other monitoring stations. If the rate of concentration change was checked using the data sets collected for this limited time period in terms of linear regression analysis, results for MAN showed the highest annual increasing rate of 16.5 ppb. It is hence suggested that the largest variability in the $CH_4$ distribution patterns at MAN observatory may be reflected by the high irregularity in its source/sink processes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.331-338
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• 2004

Folate nutrition in early pregnancy is crucial in order to prevent neural tube defects (NTDs) in the fetus and maternal folate deficiency in late pregnancy If the influencing factors on maternal folate status are identified we may be able to detect the women at most risk of folate deficiency. This study intends to determine folate intakes, assess the levels of serum folate, erythrocyte folate, and plasma homocysteine, and reveal theinfluencing factors on maternal folate status in early pregnancy. A total of 151 healthy women in their first trimester volunteered for this study. The average length of gestation period was 9.1$\pm$ 2.3 weeks and seventy subjects were primipara. They consumed 1599$\pm$589 ㎉/day of energy and 230.8$\pm$145.2 $\mu\textrm{g}$/day of folate. This represented 72.5％ and 46.2％ of the Korean RDA respectively for pregnant women in the first half of Pregnancy. Results show that they consume less folate and energy due to morning sickness. Morning sickness correlated negatively with the intakes of energy, folate, ana Kimchi also. Their levels of serum folate, erythrocyte folate, and plasma homocysteine were 5.5$\pm$1.9 ng/mL, 266.6$\pm$75.0 ng/mL, and 7.0$\pm$1.8 $\mu$mol/L, respectively. Results indicate that 7.8% were deficient and 60.3% were borderline deficient in serum folate, 4.3% were deficient in erythrocyte folate, however, all had normal levels of plasma homocysteine. Results indicate that the folate status was not poor Contributing factors influencing serum folate concentrations ($R^2$= 0.724, p = 0.0001) were self-reported health status (+), folate intake (+), age (-), length of gestation (-), and homocysteine levels (-). Factors influencing erythrocyte folate concentrations ($R^2$ = 0.570, p = 0.0029) were the infant birth height of the last pregnancy (+), energy intake (+), age (-), plasma homocysteine concentration (-), and education level (-). Factors influencing plasma homocysteine concentrations ($R^2$= 0.450, p = 0.0051) were income level (+), prepregnancy weight (+), serum folate concentration (-), and the infant birth weight of the last pregnancy (-). These results indicate that pregnant women are likely to have a folate deficiency if they are in poor health status, having a history of delivering small infant and low energy and/or folate intake, and/or are older. And folate status is likely to decline as pregnancy progresses.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.349-355
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• 2004

The purpose of this study was to estimate effect of academic examination stress on taste perception and nutrient intakes in university students. Physical status, blood pressure, stress score using stress test of 2 types, recognition threshold and preference for taste, nutrient intakes using diet record method were measured before and after examination in 20 subjects. Mean age, height, weight, and BMI of the subjects were 23.39$\pm$1.20 years, 164.56$\pm$7.99 cm, 60.66$\pm$13.23 kg, 22.28$\pm$4.56 kg/$m^2$, respectively. Stress scores before examination of the subjects were significantly higher than those after examination. There were no significant differences in blood pressure, pulse rate, recognition threshold and just right concentration for sweetness and saltness, and food and nutrient intakes between pre- and post-examination. There were significantly positive correlation between stress score and diastolic blood pressure. And threshold concentration for saltness was positively correlated with threshold concentration for sweetness and animal protein intake. These results show no effect of examination stress on taste perception and nutrient intakes in university students. This may be due to low level of stress. Therefore, it is needed to study about effect of more higher level of stress on taste perception and nutrient intakes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.356-364
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• 2004

The preference and frequency of use on instant foods were investigated for university students studying tourism science. The most preferred instant food group was noodles, and Tangs, Baps, Gooks, Zooks, one-dishfoods were preferred in order. The most preferred instant food was Cupramyeon. The preference score on instant foods of Tangs, Gooks and One dish foods for male students significantly was higher than that of female students. Also, students majoring non-cooking like instant food more than those majoring culinary science (p<0.05). The highest frequency of use was shown in group of Baps and noodles, followed by one-dish food, Gooks, Tangs, Zooks in order. The largest number of students answered 'TV' and 'curiosity' to the question on the motives of use. The most students Purchased instant foods at 'convenience store' and 'small retail store'.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.160-169
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• 2002

This study was carried to investigate the nutrition knowledge, dietary habits and nutrition attitude of 227 teachers of elementary and middle school in Masan city. The survey was conducted by a self-administered questionnaire. The results showed that the subjects had a high level of perceived nutrition knowledge (85.2%), but the accuracy of the knowledge was 76.2%, and percentage of correct answers was 65.5%. The average nutrition knowledge score was 13.1 out of possible 20 points, the average score of dietary habits was 76.2 and nutrition attitudes score was 70.8 out of 100 points. Most of the subjects are belonged to the 'good'group in terms of nutrition knowledge, dietary habits and nutrition attitudes level. Female teachers scored significantly higher on nutrition knowledge and nutrition attitudes than male teachers did (p<0.001). And elementary school teachers scored significantly higher on dietary habits than noddle school teachers (p<0.01). There was a highly significant correlations between nutrition knowledge and nutrition attitude (r =0.3, p<0.001); dietary habit and nutrition attitude (r : 0.4, p<0.001). But the correlation between nutrition knowledge and dietary habits was not significant.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.4
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• pp.627-635
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• 2003

This study was performed to investigate the relations between dietary habit and academic achievement, subjective health judgement, and physical status. The subjects consisted of freshmen in university and answered to questionnaires through the Internet. The questionnaire consists of the dietary habit, academic achievement (College Scholastic Ability Test), subjective health judgement, and physical status during their 3$^{rd}$ grade in high school days. Data were collected from 3,612 people. Over 33% of respondents had their breakfast daily. Subjects who had breakfast below twice per week were 37.9%. The major reason of skipping breakfast was lack of time to eat breakfast (62.8%). The subjects who recognized the importance of breakfast were 80.6% (p＜0.001). More than half (52.7%) thought that dinner was most tasty. People who ate breakfast regularly had a tendency to recognize their health state were in good health (p＜0.01). There was no significant difference of BMI (body mass index) according to the frequency of breakfast per week. The subjects who had their breakfast regularly and well-balanced dietary habit reported higher marks in the College Scholastic Ability Test. In contrast, the subjects who rarely had breakfast showed poor marks of academic achievement and subjective health judgement. According to these results, a good dietary habit is considered to be important to academic achievement and confidence in health. Therefore we suggest the school breakfast program and nutrition education program should be required for teenagers. In addition, the findings from this study would provide the basic information for nutrition education in Korean teenagers..

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.877-884
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• 2002

This study was carried out to examine nutrients intake and food preference in 100 elderly people aged over 85 years residing in Namhae-gun Kyungnam. Mean daily energy intake and Korean recommended dietary allowances (RDA) percent were 1547.6$\pm$452.7 kcal and 91.5%, respectively. Mean daily intakes of protein (63.1$\pm$28.2 g), iron (16.7$\pm$11.2 mg), vitamin Bi (1.0410.4 mg) and vitamin C (97.0$\pm$45.3 mg) were higher than RDA. The intakes of calcium (418.1$\pm$189.7 mg) and vitamin B2 (0.94$\pm$0.5 mg) were shown to be 58.4% and 78.4% of the RDA. Females had higher intakes of energy and most other nutrients than males. Major food source of energy and protein intakes was rice and cereals, and that of lipid intake was meat, fish, egg and beans. Cooked rice, all kind of vegetables, fish, yogurt and sugars were preferred to the subjects. The most preferred taste was sweet.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.5
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• pp.565-571
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• 2006

The purpose of this study was to investigate the regional differences in anthropometric measurement, dietary behavior and nutrient intake among the nation-wide college students participating in a nutritional education program via internet. The subjects were 1614 college students (male: 752, female: 862) and divided into 4 regional groups. A cross-sectional survey was conducted using a self administered questionnaire, and the data were collected via internet or by mail. The nutrient intake data collected from food record were analyzed by the Computer Aided Nutritional Analysis Program. Data were analyzed by SPSS 10.0 program. Average age of male and female college students were 23.6 years and 21.0 years, respectively. Most of the male and female college students had poor eating habits, such as unbalanced meals and skipping meals. In particular, more than 60% of the male college students in Chungcheong and Gyeongsang areas had irregularity of meal time. Female students in Seoul and Incheon areas showed significantly higher consumption frequency of yellow and green leafy vegetables compared to Chungcheong and Gyeongsang areas. Female students in Seoul, Incheon and Chungcheong areas showed significantly higher consumption frequency of milk and milk products compared to Gyeongsang area. Calorie, vitamin A, calcium and iron intakes of the male students and calorie, vitamin A, vitamin $B_2$, niacin and calcium intakes of female students were lower than the Korean RDA. Female students in Incheon area showed significantly higher vitamin C and iron intakes compared to the other areas. These results provide a nation-wide information on dietary behavior and nutrient intake among Korean college students.

• Journal of Dental Rehabilitation and Applied Science
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• v.17 no.4
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• pp.283-305
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• 2001

The purpose of this study was to analyze the stress distribution of condylar regions and edentulous mandible with implant-supported cantilever prostheses on the certain conditions, such as amount of load, location of load, direction of load, fixation or non-fixation on the condylar regions. Three dimensional finite element analysis was used for this study. FEM model was created by using commercial software, ANSYS(Swanson, Inc., U.S.A.). Fixed model which was fixed on the condylar regions was modeled with 74323 elements and 15387 nodes and spring model which was sprung on the condylar regions was modeled with 75020 elements and 15887 nodes. Six Br${\aa}$nemark implants with 3.75 mm diameter and 13 mm length were incorporated in the models. The placement was 4.4 mm from the midline for the first implant; the other two in each quardrant were 6.5 mm apart. The stress distribution on each model through the designed mandible was evaluated under 500N vertical load, 250N horizontal load linguobuccally, buccal 20 degree 250N oblique load and buccal 45 degree 250N oblique load. The load points were at 0 mm, 10 mm, 20 mm along the cantilever prostheses from the center of the distal fixture. The results were as follows; 1. The stress distribution of condylar regions between two models showed conspicuous differences. Fixed model showed conspicuous stress concentration on the condylar regions than spring model under vertical load only. On the other hand, spring model showed conspicuous stress concentration on the condylar regions than fixed model under 250N horizontal load linguobuccally, buccal 20 degree 250N oblique load and buccal 45 degree 250N oblique load. 2. Fixed model showed stress concentration on the posterior and mesial side of working and balancing condylar necks but spring model showed stress concentration on the posterior and mesial side of working condylar neck and the posterior and lateral side of balancing condylar neck under vertical load. 3. Fixed model showed stress concentration on the posterior and lateral side of working condylar neck and the anterior and mesial side of balancing condylar neck but spring model showed stress concentration on the anterior sides of working and balancing condylar necks under horizontal load linguobuccally. 4. Fixed model showed stress concentration on the posterior side of working condylar neck and the posterior and lateral side of balancing condylar neck but spring model showed stress concentration on the anterior side of working condylar neck and the anterior and lateral side of balancing condylar neck under buccal 20 degree oblique load. 5. Fixed model showed stress concentration on the anterior and lateral side of working condylar neck and the posterior and mesial side of balancing condylar neck but spring model showed stress concentration on the anterior side of working condylar neck and the anterior and lateral side of balancing condylar neck under buccal 45 degree oblique load.. 6. The stress distribution of bone around implants between two models revealed difference slightly. In general, magnitude of Von Mises stress was the greatest at the bone around the most distal implant and the progressive decrease more and more mesially. Under vertical load, the stress values were similar between implant neck and superstructure vertically, besides the greatest on the distal side horizontally. 7. Under horizontal load linguobuccally, buccal 20 degree oblique load and buccal 45 degree oblique load, the stress values were the greatest on the implant neck vertically, and great on the labial and lingual sides horizontally. After all, it was considered that spring model was an indispensable condition for the comprehension of the stress distributions of condylar regions.