• The korean journal of orthodontics
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• v.41 no.3
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• pp.174-183
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• 2011

Objective: Orthodontically induced root resorption (OIRR) involves partial loss of cementum and dentin of teeth caused by routine orthodontic treatment. It decreases root length and influences the function of affected teeth. In this study, the treatment and patient factors causing apical root resorption in Koreans were determined. The observed factors were extraction, gender, age, displacement of root apex, total treatment period, total teeth length, and shape of the root. Methods: The records of 137 patients treated with full, fixed edgewise appliances were obtained from the Department of Orthodontics, Dankook University Dental Hospital, from November 2007 to December 2008. Periapical radiographs of the maxillary central incisors and cephalometric radiographs of each patient were used to assess apical root resorption and type of tooth movement. Results: The mean amount of resorption was $1.62{\pm}1.58mm$. The amount of resorption in the extraction and non-extraction groups was $2.10{\pm}1.64mm$ and $1.18{\pm}1.39mm$, respectively. The amount of root resorption increased with the total tooth length. Severe root resorption (> 4 mm) was related to abnormal root shape (blunt, pointed, or eroded). Conclusions: The variables significantly related to OIRR were extraction, initial tooth length, and root shape.

• The korean journal of orthodontics
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• v.41 no.3
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• pp.154-163
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• 2011

Objective: The purpose of this study was to quantitatively evaluate relapse tendency after orthodontic treatment and determine the contributing factors by using the American Board of Orthodontics objective grading system (ABO-OGS). Methods: The subjects were 80 patients with more than 2 years of retention period after completing orthodontic treatment at the dental hospitals of Busan University, Kyunghee University, and Dankook University. The posttreatment (T2) and post-retention (T3) ABO-OGS measurements were analyzed in relation to age, gender, Angle's classification, extraction, retention period, and pretreatment condition (initial peer assessment rating (PAR) index, T1) by multiple regression analysis. Results: Among the 7 ABO-OGS criteria, alignment worsened but occlusal contact and interproximal contact improved in T3, but not in T2 ($p$ < 0.01). The 4 other criteria showed no significant differences. Multiple regression analysis showed that alignment, occlusal relationship, overjet, and interproximal contact were significant linear models, but with a low explanation power. Age, gender, Angle's classification, extraction, retention period, and pretreatment condition (initial PAR index, T1) had little influence on the ABO-OGS changes between T3 and T2. Conclusions: An orthodontist's understanding of posttreatment relapse tendency can be useful in diagnosis and during patient consultation.

• Journal of Korean Foot and Ankle Society
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• v.19 no.3
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• pp.102-106
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• 2015

Purpose: We wanted to compare the results between cadaveric and radiological measurements of calcaneus. Materials and Methods: Sixty three calcaneus of 33 cadavers donated between December 2012 and December 2014 were actually measured. Computed tomography (CT) images of 244 calcaneus in 122 patients of the same age group with cadavers were radiologically measured. Maximum length, maximum width, maximum height, $B{\ddot{o}}hler$ angle, Gissane angle, Fowler-Phillip angle, and tala-articular angle were measured. Results: In cadaveric measurement, the mean maximal height, length, and width were $41.8{\pm}3.3mm$, $73.3{\pm}3.4mm$, and $40.7{\pm}2.2mm$, respectively. In radiological measurement, the mean maximal height, length, and width were $38.5{\pm}4.3mm$, $74.0{\pm}5.7mm$, and $44.7{\pm}1.4mm$, respectively. In cadaveric measurement, the mean $B\ddot{o}hler$ angle, Gissane angle, Fowler-Phillip angle, and tala-articular angle were $32.1^{\circ}{\pm}6.2^{\circ}$, $110.8^{\circ}{\pm}8.1^{\circ}$, $55.8^{\circ}{\pm}6.8^{\circ}$, and $59.7^{\circ}{\pm}4.6^{\circ}$, respectively. In radiological measurement the mean $B{\ddot{o}}hler$ angle, Gissane angle, Fowler-Phillip angle, and tala-articular angle were $32.6^{\circ}{\pm}3.8^{\circ}$, $113.7^{\circ}{\pm}5.7^{\circ}$, $62.2^{\circ}{\pm}3.9^{\circ}$, and $61.6^{\circ}{\pm}6.3^{\circ}$, respectively. The mean maximal height was significantly higher in the cadaveric measurement group (p<0.001) and the mean maximal length and width were significantly higher in the radiologic measurement group (p<0.001, p<0.001). The mean Gissane angle, Fowler-Philip angle, and $B{\ddot{o}}hler$ angle were significantly higher in the CT group (p=0.001, p<0.001, p=0.016, respectively). There was no significant difference in the mean tala-articular angle (p=0.352). Conclusion: Significant differences in length parameters were observed between the cadaveric measurement group and the radiologic measurement group. However, no significant differences in angular measurements were observed between the two groups. The authors carefully conclude that radiological measurement values may be different from actual values in the calcaneus.

• Korean Journal of Psychosomatic Medicine
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• v.14 no.1
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• pp.39-46
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• 2006

Objectives: The study was intended to explore the relationships between temperament and premenstrual dysphoric disorder, to understand symptomatology of premenstrual dysphoric disorder and associated personality trait and to suggest therapeutic availability. Method : Twenty eight women, diagnosed as premenstrual dysphoric disorder by DSM-IV, were asked to complete the Korean version of Tridimensional Personality Questionnaire, and Shortened Premenstrual Assessment Form. The correlations between the severity of premenstrual symptoms and the scores of Tridimensional Personality Questionnaire were calculated. Results : The severity of symptoms of premenstrual dysphoric disorder was best explained by the harm-avoidance factor of the four dimensions of temperament. Conclusion : The symptoms of premenstrual dysphoric disorder are well explained by the harmavoidance factor and the reward-dependence factor of four dimensions of the temperament.

• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.487-498
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• 1998

This study was conducted to investigate changes of airway size, tongue and hyoid position following orthognathic surgery in mandibular prognathism, and how they are adapted to new environment in time dependent manner. 37 patients, who had recieved orthognathic surgery, were selected for this study. lateral cephalogram of each patient was taken at preoperation, immediate postoperation, and over 6 month after operation, and were traced and analyzed The findings of this study were as follows : 1. The size of airway was not changed at PNS and Epiglottis level after operation, but it was changed slightly at 2nd cervical vertebra level. 2. The hyoid was moved inferoposteriorly at immediate postoperation, and then it shifted toward preoperative position, but it remained slightly inferoposterior position. The distance from hyoid to genial tubercle decreased continuously. 3. The position of tongue was moved inferoposteriorly at immediate postoperatioa and then it shifted toward preoperation position, but the root of the tongue remained inferoposteriorly. 4. The distance between tongue and hyoid was increased at immediate postoperation and slightly decreased during follow-up period. 5. The change of the mandibular position was not significantly correlated with changes of airway size, hyoid position, tongue morphology and tongue position.

• Journal of agricultural medicine and community health
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• v.24 no.1
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• pp.115-129
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• 1999

To find the influence of family support degree on the depression of the elderly in a rural area, a questionnaire survey was made toward 163 persons who were more than 65 years old and living in a township at Chollanamdo province from January 1st to February 20th, 1998. The major findings are as follows : 1. By simple analysis significantly associated variables with depression score were residence, adequacy of pocket money, health consciousness, drinking alcohol, smoking, score of activity of daily living(ADL), score of instrumental activities of daily living(IADL), and degree of family support among female respondents(p<0.05). 2. To find the influence of family support on the depression score excluding other associated variables, multiple regression analysis was made and it was found that family support was associated significantly with affective, somatic, psychomotor and psychological domain of depression score among male, and somatic, psychomotor and psychological domain among female(p<0.05). The above finding suggest that family support degree is an important factor to be associated with the depression of the elderly in the rural area. So to deal with the depression of rural elderly, how to make close relation among family members must be considered.

• The korean journal of orthodontics
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• v.26 no.3
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• pp.267-279
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• 1996

This study was investigated the changes during treatment and retention period in the Class III malocclusion patients and explored the correlationship between factors that showed relapse tendencies and pre-treatment skeletal pattern and the changes during treatment period. Numbers of total sample were 24 and their Hellman's dental age at the start of treatment was over III B and were retained at least over 1 year 6 months. The following conclusion were obtained by comparing the differences between treatment period and retention period, and after analysing the correlationship of factors that manifested relapse tendencies. 1. The angles formed by FH plane and occlusal plane, FH plane and mandibular plane, and mandibular incisor and mandibular plane changes showed rebound effect during retention period and among them occlusal plane angle and IMPA show reverse correlationship. 2. Upward displacement of the occlusal plane at the end of treatment has returning tendency, is proportional to the displacement during treatment period, but the angle between maxillary and mandibular 1st molar to its basal bone have been constantlsy maintained during the retention period. 3. Mandibular plane decrease during retention period and downward backward rotation during treatment period show correlationship.

• Journal of Broadcast Engineering
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• v.17 no.4
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• pp.551-564
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• 2012

The purpose of this study is to gain knowledge about the influence of running time of 3D stereoscopic video on audience perceptions. This study compares the influence of running time between 20 minutes and 40 minutes of 3D stereoscopic music shows on audience perceptions such as perceived characteristics, impression, presence, entertainment, fatigue and unnatural looking images. After experiment with 40 samples, the present research found that when people watched shorter 3D stereoscopic music video, they perceived more 3D functionality, such as depth, image conveyance and message conveyance. The results also suggest that people who watched shorter 3D stereoscopic video felt more impression such as definiteness and freshness from the 3D images. Moreover, the result confirm that when watching shorter 3D images, people felt more a sense of presence. Findings of this study have important practical implications how running time is important to 3DTV viewers. Since the nature of this study is exploratory, more research about segmented running time and genre, etc. of 3D stereoscopic videos will be needed.

• Journal of Energy Engineering
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• v.21 no.3
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• pp.281-291
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• 2012

Recently, global economy has recovered and aspects of the renewable energy industry in the global competition is more fierce, the new growth engines of the major countries, including the United States and China, industry promotion policy as being deployed. Major advanced countries and Korea also invested a lot of money to wind power development as a part of renewable energy development and promoting the construction of wind power generation. The global wind power generation market is expected to further increase the scale to about 70 billion US dollars, thus, Korea as well as the installation of domestic wind power overseas actively considering. This study uses input-output analysis to estimate the role of wind power generation sector exports national economy. More specifically, this study shows what national economy effect of production-inducing effect, value-added inducing effect, and employment-inducing effect are explored with demand-driven moel. After define wind power generation sector what small sized of Input-Output table 168 sectors among 11 sectors, this study pays particular and close attention to wind power generation sector by taking the sector as exogenous specification and then investigating economic impacts of it. The wind power generation exportation case of overseas 100 billion won, production-inducing effect, value-added inducing effect, and employment-inducing effect are 205 billion won, 68 billion won and 1,054 persons, respectively. These quantitative information can be usefully utilized in the policy-making for the industrialization of wind power generation exports.

• Journal of Internet Computing and Services
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• v.17 no.3
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• pp.75-85
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• 2016

Changes in the distribution and sharing information using the Internet is changing the most part in our daily life, Utilizing the Internet of our lives to the rapid development of IT technology, are living in the off-line (off-line) and online (on-line) a mix of life, We expect now online life specific gravity is further increased. However, do not systematically implement the education of Internet ethics awareness deficiencies of objective indicators to assess the current knowledge level of the Internet ethics is the actual situation. Therefore, in this paper, it provides a development process in order to establish a common standard for the evaluation of Internet ethics index. Development procedure of Internet ethics index in order to establish a common standard, "evaluation item (draft) derivation", "Creating a questionnaire", "the calculation of the analysis and item-by-item weight of the questionnaire", and a common reference determination of the stage having. Was also a questionnaire that target 46 people to calculate the weight of the common reference. Internet ethics index evaluation model through the establishment of the common standards developed in this paper, municipal road Office of Education, related organizations, high school, such as small, medium, can be utilized as an indicator to measure the Internet ethics education level.