• The Journal of the Korea Contents Association
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• v.18 no.5
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• pp.376-385
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• 2018

The purpose of this study was to investigate the effect of mobile task information presentation using 3D multimedia on tooth carving knowledge, performance and class satisfaction for dentistry. To accomplish this purpose, we divided 66 dental students into the two groups: The experimental group was presented with mobile task information using 3D modeling. and the control group was presented task information using textbook. As a result for the study, First, Mobile task information presentation using 3D multimedia in class has significant effect on the tooth carving performance and class satisfaction. Second, tooth morphology knowledge in control group presenting task information using the text book showed relatively higher than in experimental group which presenting mobile task information using the 3D modeling. The conclusion of this study is that the class presenting mobile task information using 3D modeling can be enhances class satisfaction and, teaching and learning strategy to improve tooth carving performance.

• The korean journal of orthodontics
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• v.43 no.1
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• pp.15-22
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• 2013

Objective: The purpose of this study was to investigate the relationship between the mandibular dental and basal arch forms in subjects with normal occlusion and compare them with those of Class III malocclusion using cone-beam computed tomography (CBCT). Methods: CBCT images of 32 normal occlusion (19 males, 13 females; 24.3 years) and 33 Class III malocclusion subjects (20 males, 13 females, 22.2 years) were selected. Facial axis and root center points were identified from the left to right mandibular first molars. Distances between the facial axis and root center points for each tooth were calculated, and 4 linear and 2 ratio variables were measured and calculated for each arch form. The variables were compared between groups by independent t-test. Pearson correlation coefficient was applied to assess the relationships between dental and basal variables within each group. Results: The mandibular dental and basal intercanine widths were significantly greater in the Class III group than in normal occlusion subjects (p < 0.05). The dental and basal intercanine widths as well as the dental and basal intermolar widths were strongly correlated in normal occlusion and moderately correlated in Class III malocclusion. Conclusions: The dental arch form demon strated a strong positive correlation with the basal arch form in the normal occlusion group and moderate correlation in the Class III malocclusion group. These results might be helpful for clinicians to have a better understanding of the importance of basal arch form in the alveolar bone.

• The korean journal of orthodontics
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• v.47 no.3
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• pp.167-175
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• 2017

Objective: To evaluate the differences in maxillomandibular transverse measurements at either the crown or the estimated center of resistance (CR), and to compare values between normal occlusion and Class III malocclusion groups. Methods: Dental casts and computed tomography (CT) data from 30 individuals with normal occlusion and 30 with skeletal Class III malocclusions were evaluated. Using the casts, dental arch widths (DAWs) were measured from the cusp tips, and basal arch widths (BAWs-cast) were measured as the distance between the points at the mucogingival junction adjacent to the respective cusp tips. The BAWs determined from CT (BAWs-CT) images were measured from the estimated CRs of the teeth. Results: None of the DAW measurements or maxillomandibular DAW differences showed statistically significant intergroup differences. In contrast, the maxillary BAWs-CT and BAWs-cast were lesser in the Class III malocclusion group than in the normal occlusion group. The mandibular BAWs-CT were significantly greater in the Class III malocclusion group than in the normal occlusion group. Moreover, the maxillomandibular BAW differences on both CT and cast showed significant intergroup differences in all transverse measurements. Conclusions: The maxillomandibular DAW differences showed no significant intergroup differences. In contrast, the maxillomandibular BAW differences on both CT and cast showed significant intergroup differences in all transverse measurements. The maxillomandibular BAW differences at the estimated CRs, measured using CT or casts, can reveal underlying transverse maxillary basal arch deficiencies in patients with skeletal Class III malocclusions.

• The korean journal of orthodontics
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• v.28 no.5 s.70
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• pp.751-761
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• 1998

The purpose of this study was to find the characteristics of lateral crphalogram of skeletal class III malocclusion patients to whom orthognathic surgery was essential. For this study 37 patients with skeletal class III and going to treat or be treated orthognathic surgery(age 7-17) were selected to experimental group and 56 people with normal occlusion (age 8-13) were selected to normal group and the two groups were evaluated and statistically analyzed and the results were as follows 1. In comparison of experimental group and normal group in prepubertal group, there were significant differences in ANS-U1/Me-L1, Mx. Length/Mn. Length, S-N/Go-Me, Wits, ANB, SN-Pog, IMPA, Facial Convexity, APDI (p<0.05) 2. In comparison of experimental group and normal group in pubertal group, there were significant differences in ANS-U1/Me-L1, S-Go/N-Me, Mx.Length/Mn.Length, S-N/Go-Me, Wits, Saddle Angle, SNB, ANB, SN-Pog, IMPA, Interincisal Angle, Facial Convexity, APDI (p<0.05) 3. Among items showing characteristics of skeletal class III malocclusion, there were no significant differences between prepubertal group and pubertal group in other items except Mx. Length/Mn. Length,APDI (p<0.05) 4. The significant correlationship was the highest between Saddle Angle and SNB, SN-Pog and SNB, ANB and Facial Convexity in experimental group

• Communications of Mathematical Education
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• v.37 no.3
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• pp.393-417
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• 2023

The necessity of this study was to improve academic achievement and math attitudes through leveled reciprocal peer learning, and the specific purpose was as follows. First, each unit seeks to select learning methods and contents for each level of class for reciprocal peer learning, second, develop activity sites for each level through curriculum analysis, and third, improve academic achievement and math attitudes through classes that apply reciprocal peer learning activities. The study was conducted on 60 second graders of 00 High School in 00 Metropolitan City. Two classes were selected for the midterm exam results for the first semester of the second grade. Class 1 was divided into the experimental group and the other class 1 was divided into the comparative group, and 13 classes were conducted for about 2 months from May 1 to July 4, 2020. The experimental group (30 students) was a class that applied leveled reciprocal peer learning activities, and the comparative group (30 students) was a class that was taught based on traditional textbooks. As a result of this study, first, in this study, it was possible to improve academic achievement and math attitudes by setting learning contents for each unit and applying reciprocal peer learning activities for each level. Second, the experimental group taught by applying leveled reciprocal peer learning activities was effective in academic achievement and math attitudes compared to the comparative group taught based on traditional textbooks to students in the upper, middle, and lower groups. Third, in the class applying leveled reciprocal peer learning activities, low-level students who were neglected in math classes were also interested in the class and actively participated in it, showing improvement.

• The korean journal of orthodontics
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• v.40 no.3
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• pp.134-144
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• 2010

Objective: The aim of this study was to evaluate the volumes and areas of the upper airways in children with Class II malocclusion, using three dimensional cone-beam computed tomography (CBCT) and to compare the volumetric and cross-sectional measurements and cephalometric variables to investigate possible relationships between the upper airway and facial morphology. Methods: CBCT scans were obtained from 37 subjects (17 boys and 20 girls; average age, 11.02 years). The upper airway volumes and areas were measured, and compared with cephalometric variables. Results: The area of the PNS-posterior plane ($S_{PP}$) was significantly smaller in the Class II malocclusion group (p < 0.05). Also, the volumetric and cross-sectional measurements were lower in Class II than in Class I malocclusion groups, although the differences were not significant between the two groups (p > 0.05). The Class II malocclusion group showed significantly smaller values of PFH, mandibular body length, pog to N perp and showed larger values of FMA, ANB, and facial convexity than the Class I malocclusion group. The volume of the upper airway in front of PNS point (WN) showed negative correlation with ANB (p < 0.05). Conclusions: The Class II malocclusion group had a narrower upper airway associated with a decreased posterior facial height and a divergent growth pattern than the Class I malocclusion group.

• Journal of the Korean Society of Earth Science Education
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• v.10 no.2
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• pp.91-103
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• 2017

This study has developed the earth science class model based on flipped learning and analyzed the effects of that model at the elementary pre-teachers' science classes. The model of this study, the material which was consists of all contents and information about classes was offered to learners before science class as a substitute for preceding homework at general flipped learning. In science class, the knowledges which were recorded in materials were explained directly to learners by instructor for 20minutes. So the learners resolved some inquiry questions in materials through mutual debate collaboration with learners in small group. After inquiry questions' resolving, the learner among small group makes a presentation in front of the whole class. At the same time, the instructor evaluated learning action of all small groups' learners during the classes as process evaluation. The final evaluation results of semester were obtained scores of the small group in 14 classes and the achievements of individual portfolio as final exam. The learners were very positive perception to this science class model, why it is helped to concentrate on the class, extended debating and thinking ability. Consequently, the class model of this study is useful to applicate the earth science classes.

• The korean journal of orthodontics
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• v.19 no.3
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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.

• Journal of the Chungcheong Mathematical Society
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• v.23 no.3
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• pp.547-553
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• 2010

In this paper we prove that real quadratic function field F over ${\mathbb{F}}_q(T)$ has infinite 2-class field tower if the 4-rank of narrow ideal class group of F is equal to or greater than 4 when $q{\equiv}3$ mod 4.

• Journal of the Korean Society for Library and Information Science
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• v.41 no.4
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• pp.49-68
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• 2007

To promote information service and to encourage active participation from the group categorized as the alienated class(group of people) this study suggests the basic concepts and strategy for the information services to alienated class who does not have full public library services. The paper classifies three separate groups of alienated groups, handicapped. poor(economically unfortunate group) and elderly group. The service shall consider their needs from their own Point of concern and interests. There are three distinctive considerations, infra structure(facility building, space. place). administrative consideration, and equipments. Infra-structure includes the planning of the space to facilitate the equipments and reference materials which will be control)ed and moderated by a librarian. Administrative service includes the development for the educational system between the end users and external experts. It also includes the individualized education system for each group Material and equipment consideration should include the each group's specific needs such as the infra-structures which is provided for the handicapped person.