• 한국광학회지
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• 제2권1호
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• pp.31-35
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• 1991

The third-order nonlinear optical susceptibilities of $\beta$-carotene, retinal and retinol have been measured using self-induced ellipse rotation and dc-Kerr effects. The strengths of $\chi$1221(-$\omega$, $\omega$, -$\omega$, $\omega$) and $\chi$1221(-$\omega$, $\omega$, 0, 0) measured by the two different methods are not different each other significantly. And it is observed that the strength of the third order nonlinear optical susceptibility is relatively insensitive to the conformational difference between retinal and retinol. It is also demonstrated that the third order nonlinear optical susceptibility of long-chained organic molecules is dependent upon the number of the double-bonds.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권6호
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• pp.420-425
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• 2009

Purpose: The aim of this study is to analyze the correlation between incidence of mandibular angle fracture and eruption state of mandibular third molar using clinical and radiographic findings. Materials and Methods: The data were obtained from the clinical and radiographic records of 205 patients who visited the Department of Oral and Maxillofacial Surgery, Chonbuk National University Hospital for treatment of the mandibular fracture. Panoramic radiographies were taken for radiographic examination and the mandibular third molars were classified according to age, gender, position and eruption state. Data were analyzed by a chi-square statistics. Results: In this study, the incidence of mandibular angle fracture had a tendency to be greater when a mandibular third molar was present(p>0.05), but there was not a statistically significant difference. Of the 255 cases with a mandibular third molar, 67 had an angle fractures. Of the 155 cases without a mandibular third molar, 138 had not angle fracture. And the incidence of mandibular angle fracture was high at class BII(by Pell & Gregory system)(p<0.05). Conclusion: Although there was not a statistically significant difference, mandibular third molar was more susceptible to mandibular angle fracture. When the reduction of mandibular angle fracture, it was recommended that mandibular third molar should be extracted especially in case of pericoronitis, periodontitis and other infections.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 A
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• pp.64-66
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• 2000

This paper presents an algorithm for detecting current transformer (CT). At the instants of beginning and end of saturation, the increment of the secondary current is reduced significantly, depending on the residual flux and saturation time. Thus, the third difference of the current is used to detect saturation in this paper. If the third difference is less than threshold the CT is at the beginning/end of saturation. The proposed detection method is unaffected by the amount of residual flux. The results of various tests with residual flux from -80% to +80% indicate satisfactory performance of the method.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권2호
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• pp.119-124
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• 2010

Introduction: Surgical extraction of third molar is one of the most frequently performed procedures in oral and maxillofacial surgery unit as the impacted wisdom teeth could cause various complications. Even though, however, extraction of the impacted wisdom teeth is an obligation for the reason of possible complication even for general practitioners, it has been avoided. Various factors concerning surgical extraction of impacted third molar are considered: general condition of patients, relationship with relative anatomies, aspects of impaction, surgeon's skill. Materials and Methods: The consideration and crossing analysis of these factors with 2,463 patients who visit Dankook University dental hospital to extract those impacted third molar. Results: 1. Gender doesn't affect. 2. Medical problems have more complications. 3. There are more complications in high difficulty index (DI) impacted teeth. 4. When inferior alveolar canal overlap mandibular third molar, complication rate is 26.92%. 5. The most common complication was swelling and pain. 6. There is no statistical difference between the incidence of complication and surgeon's experience. Conclusion: In regard to these results, it seems that clinical or radiological examination can predict potential complications of wisdom teeth, and it is helpful to bear in mind the fact.

• 한국임상수의학회지
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• 제17권1호
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• pp.121-128
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• 2000

The effects of cryosurgery on tear production and histological changes of the third eyelid were studied in dogs. Clinically normal 12 mixed breeds weighing 2∼6 kg were divided into three groups and treated as follows; 45 seconds double freeze-thaw treated group, 60 seconds double freeze-thaw treated group and 90 seconds double freeze-thaw treated group. The significant decrease of the tear production after cryosurgery was shown in all groups throughout the observed periods(p<0.05). However, there was no difference among groups. The main complications after cryosurgery were chemosis and conjunctival injection. Other complications such as eyelid edema, eyelid depigmentation and keratitis were more preominent in group III compared to those of groups I and II. On histopathological examination, chronic inflammatory changes and regeneration of the third eyelid glands were noted in group I and predominated loss of the third eyelid glands and necrosis of hyaline cartilage were observed in group III However, such changes were less appeared in group II. The results of this study suggested that double freeze-thaw cryosurgery for 60 seconds on the third eyelid glands would be the most effective method for treating tear staining syndrome.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권6호
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• pp.565-569
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• 2006

The purpose of this study was to assess the influence of the presence and impacted state of the mandibular third molars on the incidence of mandibular condyle fracture. A retrospective study was designed for patients presenting to the Department of Oral and Maxillofacial Surgery, Kyungpook National University Hospital and Tae-gu Fatima Hospital for treatment of mandibular fractures from January 2003 to January 2006. The independent variables in this study were the presence, degree of impaction of third molars, and the outcome variables were the incidence of mandibular condyle fractures. Hospital charts and panoramic radiographs were used to determine and classify these variables. The demographic data included age, sex, mechanisms of injuries and number of mandibular condyle fractures. The study sample comprised 136 mandibular condyle fractures in 105 patients. Result of this study demonstrated a statistically significant difference in ipsilateral condyle fractures and mandibular third molar absence(P=0.032) and bilateral condyle fractures without another fracture and mandibular third molar absence(P=0.028).

• 한국초등과학교육학회지:초등과학교육
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• 제38권3호
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• pp.360-374
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• 2019

The purpose of this study is to investigate the self-perceptions of the elementary school students' on the affective, behavioral and cognitive domains in science class. To see if there are differences in students' perceptions according to grade levels, a self-perception questionnaire was applied to third and fifth grade students in Seoul, Korea. The major results of the study are as follows. First, the perception level of the affective domain was higher than that of the cognitive domain in third grade students. There was no significant difference in the self-perception level of the fifth grade students. Both third and fifth grade students perceived the greatest improvement in the cognitive domain through one year of science teaching. Second, in the life science class, the same tendency was also observed. The students in the third and fifth grade reported that cognitive domains were the most improved through the one-year life science class. Third, when the students' perceptions were compared by grades, the third grade students showed higher self-perception scores than fifth grade students. As the grade increased, the perception scores of the students' lowered. Based on these findings, implications for science education research and teaching and learning at school are discussed.

• 유통과학연구
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• 제13권1호
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• pp.105-118
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• 2015

Purpose - The objective of this study is to verify whether there are differences between Korean and Chinese consumers in the importance of the attributes such as shopping value and loyalty in social commerce. With the purpose of finding out these differences, the following questions are set up as research questions. First, will there be a difference between Korea and China in the importance of attributes of social commerce? Second, will there be a difference between Korean and Chinese consumers in shopping value? Third, will there be a difference between Korean and Chinese consumers in their loyalty? Research design, data, and methodology - The researchers collected data through self-administered questionnaires from Korean and Chinese consumers who had used social commerce within the past six months before answering the questionnaire. First, for social commerce users in Korea, comprising male and female university students in Chungcheong, a questionnaire was circulated. For social commerce users in China, university students within Beijing were surveyed. Responses to 336 questionnaires were used, excluding those with no answers or unreliable answers. Data coding and data cleaning were used. SPSS 18.0 was used. First, exploratory factor analysis is done to verify the validity of testing tools, and Cronbach's α coefficient is used to verify credibility. For factor analysis, the Varimax method is used. To verify the internal consistency reliability of each factor, the Cronbach's α coefficient is used to verify the credibility. Second, a T-test is done to verify differences between Korean and Chinese consumers for the importance of attributes. Third, ANOVA (Analysis of variance) is done to verify differences between Korean and Chinese consumers in shopping value and loyalty. Results - When Korean and Chinese consumers use social commerce, first, the importance of the attributes of social commerce is affected by four factors; playfulness and economic factors are more important to Korean consumers than Chinese consumers. As for informativeness factors, including product information and quality, and buyer comments, there was no confirmed difference between Korean and Chinese consumers. The convenience factor is more important to Chinese consumers than Korean consumers. Second, the factors affecting shopping value for Korean and Chinese consumers were hedonic shopping value and rational shopping value. To see the difference between Korean and Chinese consumers in shopping value factors, a t-test is conducted. As a result, in the rational shopping value factors of social commerce, Korean consumers scored higher than did Chinese consumers. These results were verified to be meaningful through statistics. In the hedonic shopping value factor of social commerce, Korean consumers scored higher than Chinese consumers. These results showed a significant difference. Third, loyalty in social commerce is higher for Chinese consumers than for Korean consumers. However, there is no difference in loyalty depending on sex. Conclusions - These results will hopefully be valuable and used in the future by Korean companies that wish to enter the Chinese social commerce market.

• 한국관광식음료학회지:관광식음료경영연구
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• 제16권2호
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• pp.201-216
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• 2005

This study investigated of the differences of the image between the domestic and china tourist of the visiting in busan metropolitan city and their image evaluation were different according to the nationality. The attribute for the destination image types were measured using 27 items. The factors involved in the destination image were analysis and 7 factors emerged. The result are as follows. First, Between the domestic and china tourist of living appeared to statistical different of the destination image. Second, Between destination image and revisiting preference appeared to statistical difference. Third, Between destination image and revisiting preference appeared to statistical difference according to the nationality. Forth, Between destination image and revisiting preference appeared to statistical partially difference according to the nationality. Finally it is also appeared to the statistical difference on the job. ANOVA, t-test was utilized for the above analysis which revealed that a statistic partially difference exited between domestic and china tourist.

• 한국생활과학회지
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• 제15권6호
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• pp.985-997
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• 2006

In this study, we grasped the life time structure according to working woman's income using '2004 life time research' of Korea National Statistical Office. Concrete results are shown as follows. First, inspecting the difference of individual characteristic according to income, young women who have higher education level and larger house area had acquired more income. Second, in case of the difference of life time according to income, there was no difference of individual support time, while there was statistically significant difference of working hours, household affairs, leisure time and moving hours. Third, inspecting the individual time of working, household affairs, bringing up and leisure according to income, there was statistically significant difference by age, education level, sense of time oppression, and fatigue cognition. This individual difference was revealed more strongly in medium to low-ranked group.