• 대한치과교정학회지
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• 제19권3호
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• pp.67-78
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• 1989

This study was designed to investigate the difference of teeth and craniofacial complex between normal occlusion and Angle's Class II, div. 1 malocclusion in Korean children. The sample was divided into 2 groups, the 66 subjects with normal occlusion and 96 subjects with Angle's Class II, div. 1 malocclusion in both sexes. The results obtained were as follows: 1. No significant differences were observed in ant. cranial base length & cranial flexure (saddle) angle) between normal occlusion & Angle's Class II, div. 1 malocclusion group, but posterior cranial base length of Class II, div. 1 malocclusion group was larger than that of normal occlusion group. 2. No significant difference was observed in the anteroposterior position of Maxilla to cranial base between two groups, but mandibular position in Class II, Div. 1 malocclusion was posterior and interior to that of normal occlusion. 3. The length of maxilla (ANS-PSN) was larger in Class II, div. 1 malocclusion than normal occlusion. The length of mandibular body (Go-Me) was nor different between Class II, div. 1 malocclusion and normal occlusion. 4. Maxillary incisor position of Class II, div. 1 malocclusion to cranial base was more protrusive than that of normal occlusion, but there was no difference in mandibular incisor position between two groups.

• 대한치과교정학회지
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• 제21권2호
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• pp.419-432
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• 1991

The purpose of this study is to observe how the Class III intermaxillary elastics act upon the craniofacial structures of mixed dentition with anterior crossbites. The cephalometric headplafes of 16 childrens treated only with Class III elastics (C III elastics group) and 23 childrens treated with Class III elastics and Reverse pull headgear simultaneously (C III elastics + RPHG group) were traced, digitized and statistically analyzed. The results were as follows. 1 . Anterior displacement of maxilla was observed in both groups. 2. Simultaneous Class III elastics and reverse pull headgear group showed the counterclockwise rotation of maxilla, however Class III elastics group manifested no rotational change of maxilla. 3. Simultaneous Class III elastics and reverse pull headgear group showed the downward and backward rotation of mandible, however Class III elastics group manifested no rotational change of mandible. 4. Counterclockwise canting of occlusal plane, labial tipping of upper incisor and lingual tipping of lower incisor and mesial displacement of upper molar to pterygoid root vertical were observed in both groups.

• 농촌지도와개발
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• 제17권1호
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• pp.75-101
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• 2010

This study tried to analyze the learning effectiveness of multi-media based class by comparing with traditional classroom method. The "Basic Agricultural Technology" course that is one of the required courses of agricultural high school was selected and its contents were digitalized on MS Powerpoint for multi-media based class. The thirty students were sampled for each experimental and control groups. The homogeneity and learning achievement of sample groups were tested for experiment. Same teacher took the classes of two groups and delivered same contents of course. Only difference between two groups was the delivery method, one is traditional classroom teaching method and the other was the multi-media based class. The learning achievements and satisfaction of sample were post-tested in order to analyze the learning effectiveness by comparing two teaching methods. The results showed that there was a significant difference between experimental and control group in learning achievement after ANCOVA controlled pre-test as covariance(F=5.08, p<.05). It means that the learning achievement of multi-media based class was higher than that of traditional classroom group. The results also showed that a significant difference in students’ satisfaction between two groups (t=5.57, p<.001). This study concluded that using multi-media in class could produce more learning achievements and satisfaction of students than traditional classroom method.

• 대한지구과학교육학회지
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• 제3권3호
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• pp.184-190
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• 2010

This study is to verify the effects of classes at a finishing stage using cartoons depicting certain science textbook units on scientific attitudes and academic achievements of students, compared to those of classes using experiment and observation oriented textbooks. Participants of this study were 56 fifth graders at B Elementary School in Busan, and cartoon textbooks were developed based on 'Unit 1. Mirror & Lens' and 'Unit 3. Temperature & Wind' from a science textbook for the 1st semester, the year 5 to conduct cartoon led lessons just before ending a class till the 10th lesson, for the period of 4 weeks. The result of this study can be summarized as follows: Firstly, scientific attitudes improved better from the cartoon based lesson of a final stage than from the experiment and observation method, and especially more effective in lower groups among all other academic achievement levels as well as in male students. Secondly, academic achievements scored higher when cartoons were used in lessons than when the experiment and observation type was used, with higher groups of academic achievement levels working better, despite no significant gap existing between two genders. Thirdly, the memory transfer and sustenance of lessons were more effective in finishing class stage with cartoon studies than with experiment and observation one, and among all levels and both sexes, higher academic groups and male pupils exceeded. Fourthly, when questioned about their opinions on a cartoon led lesson for a final stage, 65% of those participants responded positively, while higher groups preferred more than lower groups. responded positively, while higher groups preferred more than lower groups.

• 미생물학회지
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• 제34권4호
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• pp.194-199
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• 1998

한강의 본류와 만나는 탄천과 중랑천에서 16S rDAN를 증폭하고 부분적인 염기서열 분석을 통하여 한강의 세균 다양성을 결정하였다. 총 27개의 클론을 분리하였으며 RFLP를 이용하여 7개의 group으로 나누었다. 탄천의 15개 클론은 4개의 group으로 나뉘어졌으며 가장 많은 클론을 포함하는 group(HT-1 클론)은 class Proteobacteria의 ${\delta}$-subdivision에 속하는 Acrobacter cryaerophilius와 높은 유사도를 보였으며, 다른 두 group(HT-6과 HT-9 클론)은 모두 clas Cytophagales에 속하였다. 중랑천의 12개의 클론은 3개의 group으로 나뉘어졌으며 가장 많은 클론을 보이는 group(HJ-1 클론)은 class Proteobacteria의 ${\alpha}$-subdivision에 속하는 Sphingomonas sp. 와 높은 유사도를 나타내었다. 전체적으로는 Proteobateria(alpha, beta and delta subdivision), Cytophagales와 Actinomycetales가 검출되었다.

• Journal of Nutrition and Health
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• 제37권4호
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• pp.316-328
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• 2004

The objective of this study was to investigate the differences in food intake patterns by the economic status. Data from the 1998 Korean National Health and Nutrition Survey were used. Using the poverty line based on the 1998 Korean minimum cost of living, the subjects (n = 10400) were classified into high class (36.1%), middle class (40.7%) and low class (23.1%). Mean intakes for other food groups except grains, potatoes and vegetables became higher as the eco-nomic levels were going up. By the family size, it was found that intakes of grains and fishes were different (p<0.05). By the economic status, intakes of fruits (p<0.05), meats (p<0.05) and fishes (p<0.01) were different. There were no significant differences in consumed types of food by the economic status. Rice was the most prevalent food in all clas-ses and its intakes increased as the economic status was going down. In the dietary patterns of main food group (GMDVF: Grain, Meats, Dairy, Vegetable and Fruit), the pattern except dairy (11011) revealed the highest proportion in high-middle class while the patterns without dairy and fruit food groups (11010) had the highest proportion in low class. The propor-tions of subjects with the low dietary diversity score (DDS) increased as economic status was going down (p<0.01). The food groups that most people do not consume were the dairy and fruit group. Proportions of people who missed one or more group increased as economic status was going down. The high dietary variety score (DVS) also was linked to a high score on the DDS and high class (p＜0.01). Thus the intakes of the dairy and fruits product should be increased in all classes. The low class especially had worse quality of food intakes pattern than that of the high or middle class. The nutrition policy and education programs need to be established according to the economic status.

• 대한수학회지
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• 제40권2호
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• pp.273-286
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• 2003

Let $F^{\alpha}$G be a twisted group algebra. A subalgebra of $F^{\alpha}$G generated by all class sums of partition P of G is called a projective class algebra in $F^{alpha}$G associated with partition P. In this paper we study various partitions of G determined by actions of certain operator groups on G and construct projective class algebras depending on the actions. With regard to projective class algebras, we investigate structures of associated skew group algebras and fixed group algebras.

• 대한치과교정학회지
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• 제28권5호
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• pp.865-875
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• 1998

교정이나 악교정 수술 환자에서 치료계획 수립과 치료결과의 평가를 위해서 지금까지 많은 수평기준선이 사용되고 있으나 정확성과 재현성 등의 문제가 존재하고 있으며, 더욱 객관적인 수평기준선이 설정 될 수 있다면 교정학 분야에서 많은 발전이 기대될 수 있을 것이다. 이에 본 연구에서는 한국 성인의 부정교합군과 성별에 따른 Sella-Nasion(SN) 평면과 Frankfort-Horizontal(FH) 평면이 이루는 각도 및 FH평면과 다른 수평면 간의 상관 관계를 조사하기 위하여 먼저 임상검사를 시행하여 총 600 여명을 대상으로 측모두부규격 방사선사진을 촬영하였다. 계측결과를 바탕으로 연구대상을 골격성 I급 부정교합군 또는 정상교합군(남 50, 여 50), 골격성 II급 부정교합군(남 50, 여 65), 골격성 III급 부정교합군(남 50, 여50)으로 분류한 후 10개의 항목을 평가하여 다음과 같은 결론을 얻었다. 1. SN평면과 FH평면이 이루는 각도는 부정교합에 따른 차이는 없었으나 성별 간에는 세 부정교합군 모두에서 차이를 보여 남자는 $7.47{\pm}2.40^{\circ}$, 여자는 $8.93{\pm}2.72^{\circ}$ 였다. 2. SN 평면 또는 FH 평면과 Mandibular Plane이 이루는 각은 모든 부정교합군에서 여자가 남자보다 컸으며, 골격성 II급 부정교합군과 III급 부정교합군이 I급 부정교합군보다 큰 각도를 나타내었다. 3. FH평면과 Palatal Plane이 이루는 각은 부정교합군 및 성별에 따른 차이를 보이지 않고 비교적 일정하였다. 4. Gonial angle은 남녀 모두 III급 부정교합군이 다른 두 부정교합군보다 큰 각도를 보였다.

• 대한치과교정학회지
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• 제48권6호
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• pp.349-356
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• 2018

Objective: This study was performed to investigate the alveolar bone of lower incisors in skeletal Class III adults of different vertical facial patterns and to compare it with that of Class I adults using cone-beam computed tomography (CBCT) images. Methods: CBCT images of 90 skeletal Class III and 29 Class I patients were evaluated. Class III subjects were divided by mandibular plane angle: high (SN-MP > $38.0^{\circ}$), normal ($30.0^{\circ}$ < SN-MP < $37.0^{\circ}$), and low (SN-MP < $28.0^{\circ}$) groups. Buccolingual alveolar bone thickness was measured using CBCT images of mandibular incisors at alveolar crest and 3, 6, and 9 mm apical levels. Linear mixed model, Bonferroni post-hoc test, and Pearson correlation analysis were used for statistical significance. Results: Buccolingual alveolar bone in Class III high, normal and low angle subjects was not significantly different at alveolar crest and 3 mm apical level while lingual bone was thicker at 6 and 9 mm apical levels than on buccal side. Class III high angle group had thinner alveolar bone at all levels except at buccal alveolar crest and 9 mm apical level on lingual side compared to the Class I group. Class III high angle group showed thinner alveolar bone than the Class III normal or low angle groups in most regions. Mandibular plane angle showed negative correlations with mandibular anterior alveolar bone thickness. Conclusions: Skeletal Class III subjects with high mandibular plane angles showed thinner mandibular alveolar bone in most areas compared to normal or low angle subjects. Mandibular plane angle was negatively correlated with buccolingual alveolar bone thickness.

• 대한치과교정학회지
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• 제22권1호
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• pp.109-121
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• 1992

Temporomandibular joint is a major structure to play an important role in the function & stability of the occlusion as well as the stomatognathic system. Therefore, the TMJ is the structure that requires the complete analysis for diagnosing and planning treatment of pathologic changes by TMJ dysfunction and malocclusion. So, in this study, to evaluate TMJ situation in Korean malocclusion, based on the previous accomplishments, students of the dental college of Won-Kwang Univ. are surveyed and selected in terms of Angle's classification of malocclusion, whose TMJ radiographs were taken in the centric occlusion and centric relation. In each maiocclusion groups, the mean and standard deviation of anterior, posterior and superior joint space of the right, left and both side in CO & CR are evaluated and also those of the fossa height and the articular eminence angle of the right, left and both sides are evaluated. The obtained results were as follows: 1. In the correlation coefficient between the malocclusion groups, no other items except the posterior joint space of the right side in CR between in class I and class III are significant. 2. In the correlation coefficient between the right and left side, the each joint space in class I malocclusion group and class II malocclusion group are significant. 3. In the change of each joint space during the transmit from CO to CR, there is a tendency of increasing anterior joint space and decreasing posterior, superior joint spaces in class I, II malocclusion and increasing superior joint space and decreasing anterior, posterior joint space in class III malocclusion, which is significant in the correlation coefficient, but not significant in the T-test. 4. In each malocclusion group, the correlation coefficient between the posterior joint space and the superior joint space in C.R is highly significant. 5. The fossa height of class II malocclusion group is lesser than that of class I or class III, which is not significant in T-test. 6. In the correlation coefficient between Rt. and Lt. side in the fossa height, it is not significant in class I and class III group, but significant in class II malocclusion group. 7. The articular eminence angle of class II malocclusion group is larger then that of class I or class III groups, which is fairly significant. 8. In the correlation coefficient between Rt. and Lt. side in the articular eminence angle, it is significant in each malocclusion group.