• The korean journal of orthodontics
• /
• v.43 no.3
• /
• pp.134-140
• /
• 2013

Objective: To evaluate lower incisor position and bony support between patients with Class II average- and high-angle malocclusions and compare with the patients presenting Class I malocclusions. Methods: CBCT records of 79 patients were divided into 2 groups according to sagittal jaw relationships: Class I and II. Each group was further divided into average- and high-angle subgroups. Six angular and 6 linear measurements were performed. Independent samples t-test, Kruskal-Wallis, and Dunn post-hoc tests were performed for statistical comparisons. Results: Labial alveolar bone thickness was significantly higher in Class I group compared to Class II group (p = 0.003). Lingual alveolar bone angle (p = 0.004), lower incisor protrusion (p = 0.007) and proclination (p = 0.046) were greatest in Class II average-angle patients. Spongious bone was thinner (p = 0.016) and root apex was closer to the labial cortex in high-angle subgroups when compared to the Class II average-angle subgroup (p = 0.004). Conclusions: Mandibular anterior bony support and lower incisor position were different between average- and high-angle Class II patients. Clinicians should be aware that the range of lower incisor movement in high-angle Class II patients is limited compared to average- angle Class II patients.

• The korean journal of orthodontics
• /
• v.41 no.2
• /
• pp.127-137
• /
• 2011

Objective: The aim of the study was to compare the opening and protrusive mandibular movements between Class I and Class II malocclusions in healthy adolescents by clinical and axiographic evaluations. Methods: Mechanical axiography was performed on non-orthodontically treated, temporomandibular disorder (TMD)-free adolescents (12 - 16 years) with Class I (n = 38, 16 boys, 22 girls) or Class II (n = 40, 19 boys, 21 girls) malocclusion. Opening and protrusive movements were measured clinically and axiographically. Intergroup comparisons were evaluated by t-tests. Results: In opening movement, the maximum clinical opening capacity was significantly different (p ${\leq}$ 0.05) between the groups. In protrusive movement, the Class II group had significantly greater maximum clinical protrusion (p < 0.001) and maximum axiographic protrusive length (p < 0.01) than the Class I group. No significant difference in the other opening and protrusive axiographic measurements was observed. Conclusions: TMD-free adolescents with Class II malocclusion have increased protrusive capacity compared with TMD-free adolescents with Class I malocclusion; however, the detected differences could be normal variations during adolescence.

• Journal of the Korean Society of Food Culture
• /
• v.26 no.3
• /
• pp.249-260
• /
• 2011

The current research aims to verify whether distance learning can be adopted in practical cooking class for Korean foods in a two-year college. The distance learning education can be a supplementary method to the traditional cooking class. The face-to-face teaching method and the distance learning method were compared in order to determine which of the one is more effective teaching method in the practical cooking class. The results of the present experimental study were analyzed based on the participant's learning expectation and satisfaction, the evaluation of the experimental process, and the academic performance. The results of this study showed that the participants in the face-to-face class evaluated their class experience higher than those in the distance learning class with respect to the participant's learning expectation and satisfaction, and the evaluation of the experimental process. On the contrary, regarding the academic performance, the participants in the distance learning class showed higher scores than those in the face-to-face class. The end result supports the claim that the distance learning method is more effective in the participants for gaining cooking knowledge.

• Imaging Science in Dentistry
• /
• v.46 no.2
• /
• pp.117-125
• /
• 2016

Purpose: This study evaluated and compared interradicular distances and cortical bone thickness in Thai patients with Class I and Class II skeletal patterns, using cone-beam computed tomography (CBCT). Materials and Methods: Pretreatment CBCT images of 24 Thai orthodontic patients with Class I and Class II skeletal patterns were included in the study. Three measurements were chosen for investigation: the mesiodistal distance between the roots, the width of the buccolingual alveolar process, and buccal cortical bone thickness. All distances were recorded at five different levels from the cementoenamel junction (CEJ). Descriptive statistical analysis and t-tests were performed, with the significance level for all tests set at p<0.05. Results: Patients with a Class II skeletal pattern showed significantly greater maxillary mesiodistal distances (between the first and second premolars) and widths of the buccolingual alveolar process (between the first and second molars) than Class I skeletal pattern patients at 10 mm above the CEJ. The maxillary buccal cortical bone thicknesses between the second premolar and first molar at 8 mm above the CEJ in Class II patients were likewise significantly greater than in Class I patients. Patients with a Class I skeletal pattern showed significantly wider mandibular buccolingual alveolar processes than did Class II patients (between the first and second molars) at 4, 6, and 8 mm below the CEJ. Conclusion: In both the maxilla and mandible, the mesiodistal distances, the width of the buccolingual alveolar process, and buccal cortical bone thickness tended to increase from the CEJ to the apex in both Class I and Class II skeletal patterns.

• Imaging Science in Dentistry
• /
• v.48 no.3
• /
• pp.185-190
• /
• 2018

Purpose: The aim of this study was to compare the location and the shape of the mandibular lingula in skeletal class I and III patients using panoramic radiography and cone-beam computed tomography. Materials and Methods: The sample group included 190 skeletal class I patients and 157 class III patients. The location of the lingula in relation to the deepest point of the coronoid notch was classified into 3 types using panoramic radiographs. The shapes of the lingulae were classified into nodular, triangular, truncated, or assimilated types using cone-beam computed tomographic images. The data were analyzed using the chi-square test. Results: The tips of the lingulae were at the same level as the coronoid notch in 75.3% of skeletal class I patients and above the coronoid notch in 66.6% of class III patients. The positions of the lingulae in relation to the deepest point of the coronoid notch showed statistically significant differences between class I and class III patients. The most common shape was nodular, and the least common was the assimilated shape. Although this trend was not statistically significant, the triangular shape was more frequently observed in class III patients than in class I patients. Conclusion: The locations and the shapes of the mandibular lingulae were variable. Most of the lingulae were at the same level as the coronoid notch in skeletal class I patients and above the coronoid notch in skeletal class III patients. The nodular and assimilated-shaped lingulae were the most and the least prevalent, respectively.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.8 no.3
• /
• pp.357-365
• /
• 2001

Purpose: The purpose of this study was to identify the death orientation of college student nurses and to evaluate the effectiveness in death orientation of a class on 'hospice care'. this was done by investigating the difference between the death orientation before and after the class. Method: The instrument used in this Investigation was the death orientation scale developed by Thorson and Powell (1988). The subjects of the study were the 47 college student nurses in a 'hospice care' class. The research was carried out between March 2, 2001, when the class began, and June 21, 2001 when the class ended The collected data were examined using arithmetic mean, percentage, t-test, ANOVA. Result: The results of the study are as follows : 1. The average death orientation score of the subjects before the class was 2.80. 2. There were a significant difference in the death orientation scores before and after the class (p<0.001). Before the class, 'hospice care', the students had an average score of 2,80. Their average score decreased to 2.55 after the class. Of 25 death orientation items on the scale, 14 items decreased significantly after the class as compared to before the class. 3. According to personal attributes (religion. the existence of religion, the experience of a death in recently) of subjects, there were no significant statistical differences in death orientation (p>0.05). Conclusion: This study showed that a class on hospice care was effective in changing the death orientation of student nurses.

• 대한공업교육학회지
• /
• v.30 no.1
• /
• pp.106-119
• /
• 2005

Many problems with the offline class, which is the traditional education type in corporations or universities, were indicated and people hoped that e-learning, which is web-based instruction, would solve these problems. However, e-learning also has weak points in that it should be self-paced and media-based in many ways. Therefore, when considering the good and weak points of offline classes and e-learning, blended learning seems to be necessary. Until now, blended learning has usually been used in corporations, and there have been almost no studies on the effectiveness or management of blended learning in universities. Thus, in this study, I would like to design blended classes, manage them at the level of university classes, and verify the effectiveness of blended classes, by comparing academic achievement, student participation, and student satisfaction. The subject students who signed up for Computer & Technology at C University in 2005 were divided into three study groups: offline class, online class, and blended class. The offline class was taught using the traditional class teaching method. For the online class and the blended class, multimedia contents were developed and a different LMS was used. The results of 13 weeks of teaching are as follows. For the academic achievement in the offline, online and blended classes, there was no statistically significant difference (f=2.387, p=.096). But when comparing the average achievement, the average of the blended class was higher than that of the other classes, so that it can be said that the blended class has positive effects on academic achievement. Second, when comparing the learners' participation in the online class and the blended class, the total posts were 85 and 138 respectively, which shows a considerable difference. The hit counts for each post in the online class and the blended class are 10 and 20, respectively. Moreover, the login counts for subjects are 3 in the online class and 4 in the blended class. In the questionnaire for the students' academic satisfaction in the online class and the blended class, all of the 15 items showed higher satisfaction in the blended class. Considering all these results, if adequate media are properly combined, the blended class is better than either the pure online class or the pure offline class.

• Management Science and Financial Engineering
• /
• v.17 no.2
• /
• pp.23-37
• /
• 2011

In this paper, we address a layout design problem for determining an optimal 4-class-based dedicated linear storage layout in a class of unit load storage systems. Assuming that space requirement for a class is the sum of the maximum inventory levels of products assigned to the class, and that one-way travel time is a linear function of storage index, we formulate a 4-class-based dedicated linear storage problem PTL[4] and provide an exact splitting algorithm with $O(n{\lceil}logn{\rceil})$. Our algorithms could be applied to more than a 4-class-based dedicated storage layout problem with slight modification in order to reduce computational execution time.

• Journal of Korean Elementary Science Education
• /
• v.39 no.1
• /
• pp.133-144
• /
• 2020

The purpose of this study is to identify the effect of Teacher Participation-oriented Education Program (TPEP) for Elementary School Teachers to Improve Class Expertise in Science Classes with a focus on visual attention. The participants were two elementary school teachers in Seoul and taught science subjects. The lesson topic applied to this study were 'Structure and Function of Our Body' in the second semester of fifth grade and 'Volcano and Earthquake' in the second semester of fourth grade. The mobile eye tracker SMI's ETG 2w, which is a binocular tracking system was used in this study. In this study, the actual practice time, participant's visual attention, visual intake time average, and visual intake time average were analyzed by class phase. The results of the study are as follows. First, as a result of analyzing the actual class execution time, the actual class execution time was almost in line with the lesson plan after the TPEP application. Second, visual attention in the areas related to teaching and learning activities was high after applying TPEP. Factors affecting the progress of the class and cognitive burdens were identified quantitatively and objectively through visual attention. Third, as a result of analyzing the visual intake time average of participants, there was a statistically significant difference in all classes. Fourth, as a result of analyzing the visual intake time average of participants, the results were statistically significant in the introduction(video), activity 1, activity 2, and activity 3 stages in the lecture type class. The Teacher Participation-oriented Education Program (TPEP) for Elementary School Teachers to Improve Class Expertise in Science Classes can extend elementary science class expertise such as self-class analysis, eye tracking, linguistic, gesture, and class design beyond traditional class analysis and consulting.

• Educational Technology International
• /
• v.21 no.2
• /
• pp.193-216
• /
• 2020

This study investigated university students' perspectives on good class and instructional practices through social network analysis. The subjects were 321 students in the third and fourth academic years in a Korean university. The subjects completed four open-ended questions, asking about experience of good class, good instructors' teaching practice, and their feelings and attitudes when participating in good class. As social network analysis, KrKwic (Korea Key Words in Context) was used to compute word frequencies and analyze semantic network structures and Ucinet Netdraw to assess centrality in the social network, consisting of degree centrality, closeness centrality, and between centrality. The results are as follows. First, students showed 5 keywords to depict what good class is, including 'understanding', 'example', 'video', 'interest', and 'communication'. Second, the characteristics of teaching methods by professors who practice good class indicate 'assignments', 'questions', 'understanding', 'example', and 'feedback'. Third, the top 5 keywords of students' attitudes as participating in good class are 'active', 'participation', 'focus', 'listening', and 'asking'. Last, keywords depicting desirable class that students most wanted to take next time are 'assignments', 'rewards', 'understanding', 'difficulty', and 'interest'. The findings from this study include the meanings of the semantic network structures of words in the text making up messages. Also this study can provide empirical evidence for educators and educational practitioners in higher education to create effective learning environments.