• The korean journal of orthodontics
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• v.31 no.4 s.87
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• pp.425-438
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• 2001

The delivery of optimal orthodontic treatment is greatly influenced by clinician's ability to predict and control tooth movement by applying well-known force system to dentition. It is very important to determine the location of the centers of resistance of a tooth or teeth in order to have better understanding the nature of displacement characteristics under various force levels. In this study, three dimensional finite element analysis was used to measure the initial displacement of the consolidated teeth under loading. The purpose of this study was to define the location of the centers of resistance at the upper six anterior segment. To observe the changes of six anterior segment, 200gm, 250gm, 300gm, and 350gm forces at right and left hand side each were imposed toward lingual direction. For this study, two cases, six anterior teeth and six anterior teeth after corticotomy, were reviewed. In addition, it was reviewed the effects of changes on the location of the center of resistance in both cases based on different degree of forces aforementioned. The results were that : 1. The instantaneous center of resistance for the six anterior teeth was vertically located between level 4 and level 5, which is, at 6.76mm, $44.32\%$ apical to the cementoenamel junction level. 2. The instantaneous center of resistance for the six anterior teeth after corticotomy was located vertically between level 4 and level 5, that is, at 7.09mm $46.38\%$ apical to the cementoenamel junction level. 3. Changes of force showed little effect on the location of the center of resistance in each case. 4. It was observed that the location of the instantaneous center of resistance for the six anterior teeth after corticotomy was changed more than the six anterior teeth without corticotomy to the apical part, and the displacement of the consolidated anterior teeth moved further in case of the consolidated teeth after corticotomy.

• Journal of dental hygiene science
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• v.14 no.4
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• pp.571-579
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• 2014

This study was conducted to provide basic data for improvement of the oral health management ability and the factors affecting oral health recognition and practice of 6th graders. The research subjects total 259 numbers of 6th grade students in two schools located in Changwon, it was investigated and analyzed with structured questionnaires. The collected data is analyzed by using IBM SPSS Statistics 19.0. The average oral health recognition score investigated were $3.19{\pm}0.41$, and $2.95{\pm}0.43$ for oral health practices. The oral health recognition was statistically significant differences by father's education (p<0.01), perceived oral health status (p<0.01), perceived grade (p<0.01), intention to attend oral health education (p<0.001). The oral health practices was statistically significant differences by father's education (p<0.01), perceived oral health status (p<0.001), perceived grade (p<0.05), parent's interest in child's toothbrushing (p<0.01), experience of oral health education (p<0.001), intention to attend oral health education (p<0.05). The factors that may improve the oral health recognition are in order of oral health practices, intention to attend oral health education, and parent's attention to child's tooth brushing. The factors that may improve the oral health practice was found to be in order of oral health recognition, parent's attention to child's tooth brushing, and perceived oral health status. As a result, in order to improve oral health management ability of 6th grade students, the surrounding environment, the attitude on oral care, the interest of oral, and the current disease status of oral health are required to be identified, then the oral health education program should be provided.

• Journal of dental hygiene science
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• v.14 no.2
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• pp.248-255
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• 2014

The objective of the paper is to analyze the extent to which elementary school students acquired, perceived, and practiced oral health knowledge provided by an elementary school-based oral health clinic (SBOHC). It is respectively investigated by gender and year of school. The paper will be relevant for developing specified oral health programs in elementary SBOHCs. By choosing three elementary schools that operate SBOHC in the school district of Daejeon Metropolitan City from April 11 to April 30, 2013, a self-administered questionnaire was given out to be answered directly by 350 students in the 4th, 5th, and 6th grades and their responses were collected. Of the collected responses, 326 responses were explored by using the SPSS 12.0. Those students' scores of oral health knowledge are found to be statistically meaningful for school year, not for gender. In them are included correct tooth brushing time, dental caries symptoms, gum disease symptoms, and correct tooth brushing method. Change in tooth brushing method after oral health education showed the statistically meaningful difference for gender and school year. In conclusion, every SBOHC should develop a variety of specified educational programs that depend on gender and grade in each elementary school.

• Journal of Korean Home Economics Education Association
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• v.17 no.2
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• pp.79-93
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• 2005

The purpose of this was to present the efficient directions of nutrition education for elementary school children. We examined the problems of eating habits. nutrition knowledge, and perception and expectations on nutrition education of elementary school children in school. This study was carried out using a self-administered questionnaire and subjects were 562 elementary school children in Gyeonggi Province. All data in this research was analyzed through SAS program, and the frequency$(\%)$ and the $mean{\pm}S.D.$ on each question were calculated. Data for each group was analyzed according to sex and the difference among the groups were treated for significance by using chi-square test and Student t-test. About $87.6\%$ of the children have a meal over three times a day, and $76.7\%$ answered that they ate at a certain time regularly everyday. Only $69.6\%$ of subjects said that they ate breakfast everyday, showing very high levels of skipping breakfast. The most common frequency of eating snacks was 'once a day' in both sexes(male $52.2\%$, female $48.6\%$). In the perception on the eating habits, $69.3\%$ of children recognized problems on dieting habits, such as unbalanced diet. irregular eating time, and overeating. The perceived and correct knowledge of nutrition were $99.5\%$ and $86.9\%$, respectively. Most of the children$(99.1\%)$ acknowledged that nutrition education need to be carried out in school. And children want to deeply deal with 'cooking', 'growth and nutrition', 'good eating habits', 'nutrition and disease', These results indicated that elementary school children tended to have undesirable eating behaviors, but the rate of children who recognize the importance and the needs of nutrition education in school was high. Therefore, their parents and teachers need to perform continuous education through a curriculum and life instruction so that students have healthy habits by considering what the problems of nutrition habits are, as the elementary students considerably recognize problems of their own dietary habits and needs of nutrition education.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.2
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• pp.223-233
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• 2013

The purpose of this study was to analyze the dietary habits and perception of vegetable intake of elementary students in Gwangju and Jeonnam Gokseong county. Data collection was conducted from 5th and 6th grade students of elementary schools in Gwangju and Jeonnam Gokseong county using a structured questionnaire survey. The SPSS program was used for statistics processing and data analysis. The chi-square test was also conducted. In terms of dietary intake habits, female students consumed their meals slower than male students. Information on dietary habits and nutrition was commonly obtained from family, including the mother or father who commonly prepared meals at home. Snacks were commonly consumed less than twice daily, with the Gwangju area having a higher frequency of snacks than the Jeonnam area. Elementary students indicated that vegetables were their least favorite food, with female students having a higher interest in vegetables than male students. The pattern and perception of vegetable intake came when the students (that did not eat vegetables) were lectured by their parents on the nutritive value of vegetables. Most students understood the important nutritional ingredients of vegetables. In the case of an interest in vegetables, the Gwangju area showed significantly more comprehension than the Jeonnam area on the definition and role of dietary fiber, the dental benefits of dietary fiber, and the identification of the environment-friendly certification mark.

• Journal of Korean Society of Forest Science
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• v.28 no.1
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• pp.1-20
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• 1975

F$\ddot{u}$r die Erforschllng der Variationen bei der Naturpopulationen der Pinus densifiora wurden drei Populationen aus Chuwangsan (Kyong-buk), Anmyondo (Chung-nam) und Odaesan (Kangwon) Ausgewiiblt. Bei je 20 Individuen jeder Population wurden die Variationen von der Eigenschaft der $\ddot{a}$usseren Gestalt, von der anatomischen und morphologischen Eigenschaft der Kiefernadel und von der Holzqualit$\ddot{a}$t an Bohrsp$\ddot{a}$nen untersucht. Das Ergebnis der Untersuchung konnte in den folgenden sechs Punkten formuliert werden. 1. Von den Eigenschaften der $\ddot{a}$usseren Gestalt ist die Geradheit des Baumstamms, der Durchmesser der Zweige und der Winkel der Verzweigung in der Odaesan Population wlinschenswerter als in anderen Populationen. 2. Es wird festgestellt, dass sich die drei Nadelmerkmale, Anzahl der Z$\ddot{a}$hne je 0.5 cm, Anzahl der Stomata-Reihen und Anzahl der Harzkan$\ddot{a}$le, sowohl zwischen den Populationen als auch zwischen den Individuen signignifikant unterscheiden. 3. Bei der Betrachtung des Harzkanal Index, der Schichtanzahl der Hypodermis und der Entfernung der Fibrovasalb$\ddot{u}$ndel wird aufgezeigt, dass sich alle drei gepr$\ddot{u}$ften Populationen geringf$\ddot{u}$gig von der normalen Kiefer unterscheiden. 4. Zwischen den Populationen ergibt sich ein Unterschied im Prozentanteil des Spatho lzes und im spezifischen Geswicht, jedoch zeigt die Breite der Jahresrings und die Tracheidenl$\ddot{a}$nge keinen Unterschied. Das spezifische Gewicht und die Tracheidenl$\ddot{a}$nge der Individuen jeder Population ist signifikant verschieden. 5. Bei dem Alter 11-20 ist der Prozentanteil des sp$\ddot{a}$tholzes am gr$\ddot{o}$ssten und wird aber danach immer geringer bis zum Alter 30; sp$\ddot{a}$ter zeigt sich dann keine sichtbare Ver$\ddot{a}$nderung mehr. Das spezifische Gewicht sich vergr$\ddot{o}$ssert bei der Zunahme des Jahresrings, nimmt aber dann in Anmyondo und Odaesan Populationen beim Alter 21-30 wieder ab. Die Tracheidenl$\ddot{a}$nge der drei Populationen besitzen die Neigung, sich nach der zunahme der Jahresringe zu vermehren. 6. Mit diesen hier behandelten Charakteren werden ganz allgemeinen die Unterschiede der drei Kiefer populationen festgestellt. Diese Ergebnisse sind sehr bemerkenswert betrachtet vom genetischen Gesichtspunkt der waldbaumpopulation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.1
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• pp.126-136
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• 2016

This study was performed to investigate menu preferences of adult customers for Korean food made from Korean traditional sauces. A total of 962 valid responses were used for data analysis. Statistical analyses were conducted using the SPSS package program (ver 20.0). The results of this study are summarized as follows: overall preferences were highest for braised spareribs, followed by braised short ribs, grilled beef ribs, and bulgogi. On the other hand, overall preferences were lowest in eggplant namul, followed by squid and radish soup, and grazed lotus roots and burdock. Female's overall preferences were significantly higher than male's for nine menu items, including japchae and seasoned acorn starch curd with vegetables, whereas male's overall preferences were significantly higher than female's for 19 menu items, including grilled deodeok and frozen pollack stew. Moreover, the menu item that was most significantly preferred was soybean sprouts soup in subjects aged under 20 years and Korean meatballs in subjects in their twenties. Subjects in their forties showed significantly higher preferences for 15 menu items, including braised hairtail, grilled deodeok, and seasoned and grilled yellow corvina compared to other age groups. Furthermore, menu preferences of production service workers were significantly higher than other groups for frozen pollack stew, loach stew, grilled dried pollack, steamed dry pollack, dried pollack soup, eggplant namul, and seasoned and grilled yellow corvina, whereas menu preferences of official professional workers and students were significantly higher than those of production service workers for braised short ribs, grilled beef ribs, seasoned and simmered chicken, mixed noodles, Korean meatballs, stir-fried rice pasta with vegetables, spicy soft bean curd stew, japchae, mung bean jelly mixed with vegetables and beef, bibimbap, and stir-fried squid. The results show that menu preferences of adults customers differed depending on gender, age, and occupation. In conclusion, the results of this study should provide foodservice managers with information about menu planning for target customers of commercial or non-commercial foodservice cafeterias and recipe development of low-sodium Korean foods.

• Journal of agricultural medicine and community health
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• v.34 no.1
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• pp.13-23
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• 2009

Objective: The objective of this study was to evaluate the association of social support with health status and health behavior. Methods:　This study was conducted with 79 elderly people in Gunja-ri, Dongsan-myun, Chuncheon. We performed face to face interview which was composed of socio-demographic characteristics, social support, health status and health behavior. The association between social support and result variables was analysed by Chi-square test and logistic regression. We used SAS ver9.1 for statistic analysis. Results: Mean age of the study population was 72.0$\pm$7.0, social support score was 14.3$\pm$4.7 with full marks of 20 and 36.25% of the total population were shown to have depression. When the social support score was changed, depression (p=0.0007) and physical exercise (p=0.0312) showed significant difference. The self-rated health status was significantly related to the relationship with family members (OR=0.25, 95% CI=0.07-0.95) and the quality of sleep was also significantly associated to the relationship with family members (OR=0.21, 95% CI=0.06-0.73). The physical exercise was done significantly less in the group without close friends than in the group with many close friends (OR=0.21, 95% CI=0.05-0.94) and the depression was significantly more in the group without community participation than in the group with community participation (OR=4.79, 95% CI=1.62-14.15). Conclusions: Through this study, we could conclude that the social support factors are associated with health status and health behavior. Therefore, to improve the health status of rural elderly, we need to approach to develop social support.

• Sleep Medicine and Psychophysiology
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• v.10 no.1
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• pp.32-38
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• 2003

Objectives: The purpose of this study is to investigate the effects of stress and personality on sleep patterns, and further, to identify potential correlations between stress and personality characteristics. Methods: A total of 174 healthy college students were subjects for this study. Participants filled out the Daily Stress Inventory before sleep and the Modified Pittsburgh Sleep Quality Index after sleep on three consecutive days. They also filled out the 16 Personality Factor Questionnaire (16-PF), BDI (Beck Depression Inventory) and STAI (State-Trait Anxiety Inventory). Results: Minor stresses highly correlated with subjective sleep quality and symptoms of non-restorative sleep. However, total sleep time, sleep latency, awakening frequency, and frequency of dreams were not explained by stress scores. The O (guilty feeling), C (low ego strength) and Q4 (high anxiety) factors of the 16-PF also highly correlated with symptoms of non-restorative sleep and significantly affected sleep patterns. BDI and STAI scores also correlated with the above personality factors and minor stresses. Conclusion: This study showed that minor stresses impaired the restorative effects of sleep. Personality characteristics such as low ego strength, high levels of anxiety, and feelings of guilt were vulnerable to minor stresses. Minor stress, various personality characteristics, different coping patterns, and emotional response are highly correlated with each other and affect sleep patterns.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.3
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• pp.156-161
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• 2012

Purpose: This study was conducted to obtain difference in fracture strength according to the diameter of one-body O-ring-type of mini implant fixture, to determine the resistance of mini implant to masticatory pressure, and to examine whether overdenture using O-ring type mini implant is clinically usable to maxillary and mandibular edentulous patients. Materials and methods: For this study, 13 mm long one body O-ring-type mini implants of different diameters (2.0 mm, 2.5 mm and 3.0 mm) (Dentis, Daegu, Korea) were prepared, 5 for each diameter. The sample was placed at $30^{\circ}$ from the horizontal surface on the universal testing machine, and off-axis loading was applied until permanent deformation occurred and the load was taken as maximum compressive strength. The mean value of the 5 samples was calculated, and the compressive strength of implant fixture was compared according to diameter. In addition, we prepared 3 samples for each diameter, and applied loading equal to 80%, 60% and 40% of the compressive strength until fracture occurred. Then, we measured the cycle number on fracture and analyzed fatigue fracture for each diameter. Additionally, we measured the cycle number on fracture that occurred when a load of 43 N, which is the average masticatory force of complete denture, was applied. The difference on compressive strength between each group was tested statistically using one-way ANOVA test. Results: Compressive strength according to the diameter of mini implant was $101.5{\pm}14.6N$, $149{\pm}6.1N$ and $276.0{\pm}13.4N$, respectively, for diameters 2.0 mm, 2.5 mm and 3.0 mm. In the results of fatigue fracture test at 43 N, fracture did not occur until $2{\times}10^6$ cycles at diameter 2.0 mm, and until $5{\times}10^6$ cycles at 2.5 mm and 3.0 mm. Conclusion: Compressive strength increased significantly with increasing diameter of mini implant. In the results of fatigue fracture test conducted under the average masticatory force of complete denture, fracture did not occur at any of the three diameters. All of the three diameters are usable for supporting overdenture in maxillary and mandibular edentulous patients, but considering that the highest masticatory force of complete denture is 157 N, caution should be used in case diameter 2.0 mm or 2.5 mm is used.