• Journal of Environmental Health Sciences
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• v.30 no.3
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• pp.191-206
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• 2004

The present study investigated the hypothesis that a extremely low frequency magnetic field partially suppresses the synthesis of melatonin in a group of 28 primary schoolchildren living nearby and 60 primary schoolchildren aged 12 years living far away from overhead transmission power lines from December 2003 to April 2004 in Seoul, Korea. The mean personal exposure levels of the primary schoolchildren living nearby overhead transmission power line were 0.37 ${\mu}$T, whereas the value for the primary schoolchildren living away from overhead transmission power line 0.05 mT. From simple analyses, the mean melatonin levels in the primary schoolchildren living nearby were lower than away from overhead transmission power line, but not statistically significant differences in the levels of the melatonin (p=0.2421), whereas the statistically significant differences in the levels of the melatonin related to the distance from residence to power line less and more than 100 m by cut-off point (p=0.0139). In multiple linear regression analyses, distance from residence to power line (p=0.0146) and dietary habit about burned meat (p=0.0170) proved to be significant risk factors in the mean nocturnal melatonin levels in the primary schoolchildren. In conclusion, these results demonstrate that urinary levels of nocturnal melatonin are not altered in primary schoolchildren exposed to extremely low frequency magnetic field(ELF-MF) at overhead transmission power line.

• The korean journal of orthodontics
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• v.50 no.3
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• pp.170-180
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• 2020

Objective: To compare short- and long-term dentoalveolar, skeletal, and rotational changes evaluated by Björk's structural method of superimposition between children with Class II malocclusion treated by functional appliances and untreated matched controls. Methods: Seventy-nine prepubertal or pubertal children (mean age, 11.57 ± 1.40 years) with Class II malocclusion were included. Thirty-four children were treated using an activator with a high-pull headgear (Z-activator), while 28 were treated using an activator without a headgear (E-activator). Seventeen untreated children were included as controls. Lateral cephalograms were obtained before treatment (T1), after functional appliance treatment (T2), and after retention in the postpubertal phase (T3). Changes from T1 to T2 and T1 to T3 were compared between the treated groups and control group using multiple linear regression analysis. Results: Relative to the findings in the control group at T2, the sagittal jaw relationship (subspinale-nasion-pogonion, p < 0.001), maxillary prognathism (sella-nasion-subspinale, p < 0.05), and condylar growth (p < 0.001) exhibited significant improvements in the Z- and E-activator groups, which also showed a significantly increased maxillary incisor retraction (p < 0.001) and decreased overjet (p < 0.001). Only the E-activator group exhibited significant backward rotation of the maxilla at T2 (p < 0.01). The improvements in the sagittal jaw relationship (p < 0.01) and dental relationship (p < 0.001) remained significant at T3. Condylar growth and jaw rotations were not significant at T3. Conclusions: Functional appliance treatment in children with Class II malocclusion can significantly improve the sagittal jaw relationship and dental relationships in the long term.

• Imaging Science in Dentistry
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• v.43 no.1
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• pp.1-6
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• 2013

Purpose: This study investigated the possible correlation between the mineralization of the second molars and the chronological age of a sample population of the state of Paraiba, Brazil. Materials and Methods: One thousand eight hundred fifty-four digitized panoramic images using a scanner of a private dental radiology service were obtained in six months. Of these, 457 were selected from patients aged 4.6 to 16 years who met certain criteria. The images were assessed twice by a radiologist with 5 years experience. A minimum interval of 30 days between the evaluations of the same patient was established. To analyze the relationship between chronological age, calcification level proposed by Demirjian et al in 1973, gender, and tooth, a multiple linear regression model was adjusted, taking age as the response variable (p<0.05). Results: The gender and calcification level were significantly correlated with the age of the patients (p<0.05). There was a significant difference between the average age of the patients' upper teeth compared to the lower ones in both genders (p<0.05). The dental development occurred earlier in female individuals than in male ones, and there was no significant difference between the right and left second permanent molars. Conclusion: It was observed that ethnic variables are related to certain parameters of age and sex identification in the Brazilian population, providing important information for forensic evaluations.

• Journal of the HCI Society of Korea
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• v.7 no.2
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• pp.17-24
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• 2012

In this study, we aim to understand how social computing features affect open source project's outcome based on the representative social coding platform, Github (http://github.com). Though there is growing interest regarding the application and effect of employing social computing features, yet empirical evidences related to the subject are still short. To bridge the gap, we conducted our research based on the following research questions: 1) How the system features of social coding platform are classified? 2) How are the use of system features and project performance related to each other? Qualitative and quantitative analysis are performed: The system features of Github are clustered according to their usage in qualitative analysis, and th relation between the feature uses and project outcome is identified by multiple linear regression test. In conclusion, we found that the use of results is also discussed.

• Korea Journal of Hospital Management
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• v.25 no.1
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• pp.46-57
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• 2020

Objectives: The purpose of this study is to evaluate the factors affecting patient satisfaction for the nursing service of comprehensive nursing care service unit in Tertiary hospital Methods: This study employed a descriptive survey to investigate the nursing satisfaction and the study data was collected from 74 patients among 83 patient who were admitted to the nursing care integration service ward of an tertiary hospital for 10 days from May 9, 2018 to May 19, 2018. Data was analyzed by descriptive statistics, t-test, ANOVA, and multiple linear regression using SPSS 21 program. Results: The average with nursing satisfaction was significantly different according to marriage type and KPCS level. It was found that physical factor and educational factor have statistically significant effect on nursing satisfaction. As physical care increase by one unit, patient satisfaction increase by 0.226(95% CI; 0.061-0.390) and also satisfaction increase by 0.443(95% CI; 0.070-0.816) as education care increase by one unit. Conclusions: As a result of study, it was found that it is necessary to provide patients with more careful nursing service in physical and educational perspective, in order to improve the service quality of comprehensive nursing care service unit.

• Journal of the Korean Society of Safety
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• v.27 no.3
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• pp.131-140
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• 2012

Though there might exist not a few differences between cyclic works and atypical works, many researchers have applied the same assessment techniques that used for repetitive works, which may result introduce bias in their conclusions. This research aimed to verify whether there exist non-negligible work characteristics and/or dissimilarity among works with different work nature and whether one of the most prevalent assessment techniques for assessing ergonomic hazards of musculoskeletal disorders, REBA, can be applied to atypical works. For a general hospital, an automobile repair shop, and two auto-part assembly plants which manufactures quite different parts, a questionnaire survey and field investigation and ergonomic assessment were carried out and analyzed statistically with reference to the 3rd Quantification technique. The results showed that there exist remarkable difference between physical factors in cyclic works and atypical non-cyclic works. As for repetitive work, body posture was significant factors affecting on musculoskeletal disorders while atypical works seemed to have none which implied that the necessity of taking psychosocial factors into account for assessment of hazards. Complain rate in repetitive works was highest shoulder, back, and neck or wrist in sequence. However, there existed no consistent trend in complain rate in atypical works. And, though weight of manufacturing objects was a common factor that can partly explain musculoskeletal complain, time duration was significant in atypical work whereas repeatability and body posture were significant in repetitive works. As being the results, to summarize, it could be said that application of conventional ergonomic assessment techniques regardless of repetitiveness would be fruitless, and that the necessity of a unique methodology focused on atypical non-cyclic works should not be neglected.

• Anxiety and mood
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• v.8 no.2
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• pp.99-105
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• 2012

Objective : The aim of this study is to evaluate the five-factor model of personality in patients with obsessive-compulsive disorder (OCD) related to obsessive-compulsive symptom severity and the distinct symptom subgroups. Methods : We recruited 95 patients with OCD and 116 normal controls in the study. We used the short version of Revised NEO Personality Inventory and the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) for the assessment. Results : Patients with OCD showed significantly higher scores in neuroticism than normal controls. On multiple linear regression analysis, we found that agreeableness and conscientiousness were associated with the total Y-BOCS scores. On subscale analysis, agreeableness and neuroticism were associated with the obsession subscale scores and only conscientiousness was associated with the compulsion subscale scores. Furthermore, we found that patients who have contamination/cleaning or symmetry/ordering/counting/arranging as a main symptom presentation had significantly higher mean scores in conscientiousness than patients who have harm due to injury/violence/aggression as a main symptom presentation. Conclusion : In this study, we found that specific personality factors are associated with the obsessive-compulsive symptom severity. In addition, this is the first study to investigate the relationship between the personality factors in the five-factor model and the distinct symptom subgroups in OCD.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.6
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• pp.1614-1628
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• 2016

The purpose of this study was to examine the relationship between the safety awareness and safety practice of international marriage woman in Kimhae and Changwon city. We carried out a questionnaire survey that was targeted at 138 subjects. Data collected were analyzed with SPSS 21.0 statistical program. Analysis methods were t-test, one way ANOVA, Scheffe test, Perarsons correlation coefficient, and multiple linear regression. The results were as follows. First, safety awareness point was an average of 4.10 point which was higher level. Safety practice point was an over intermediate level of an average of 3.23 point. Second, safety awareness had statistically significant difference according to age, year of Korea residence, born Nation, whether or not Korean citizenshilp, monthly income, temper, satisfaction of marriage. Third, safety practice had statistically significant difference according to housing, monthly income, health state, satisfaction of marriage. Fourth, safety Practice had a positive correlation with home safety awareness, traffic safety awareness, fire safety awareness, and emergency care awareness. Therefore, a higher safety awareness results in having a very well safety practice. Fifth, International Marriage Women from Japan had the highest the level in the Safety Awareness and Safety Practice. From now on, two cities should have a major concern for safety education of fire and emergency care. And the safety education based on learning need analysis need to be done substantially.

• Journal of Digital Convergence
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• v.15 no.4
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• pp.377-386
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• 2017

This study was conducted to determine the relationship between the job stress levels of 669 subway operators in Seoul after the installation of screen doors and their mental health. Data were collected using a structured questionnaire and via web site. A multiple linear regression analysis was conducted using the SPSS 20.0 statistical program. The total score of job stress turned to be higher than the standard score, and physical environment, job demand, insufficient job autonomy, interpersonal conflict and occupational climate were within the top 50% and organizational system within the top 25%. A correlation analysis revealed that job stress was positively correlated with all sub-domains of mental health. In terms of effects of job stress on mental health, there were significant differences according to job demand, organizational system, lack of reward and occupational climate, with an explanatory power of 36.6%. It is expected that this study can provide foundation for the establishment of organizational measures accustomed to job characteristics to prevent job stress of subway operators and the development and implementation of intervention programs for mental health promotion.

• Journal of Digital Convergence
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• v.18 no.7
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• pp.47-56
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• 2020

The purpose of this study is to comprehensively analyze elementary school teachers' perceptions of the use of artificial intelligence in education. Recently, interest in the use of artificial intelligence has increased in the field of education. However, there is a lack of research on the perceptions of elementary school teachers using AI in education. Using descriptive statistics, multiple linear regression analysis, and semantic differential meaning scale, 69 elementary school teachers' perceptions of using AI in education were analyzed. As a results, artificial intelligence technology was perceived as most suitable method for assisting activities in class and for problem-based learning. Factors which influence the use of AI in education were learning contents, learning materials, and AI tools. AI in education had the features of personalized learning, promoting students' participation, and provoking students' interest. Further, instructional strategies or models that enable optimized educational operation should be developed.