• The korean journal of orthodontics
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• v.28 no.5 s.70
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• pp.717-729
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• 1998

This study was done to estimate arch forms and dimensions at the bracket level where archwire was placed in Angle's Class I first premolars extraction cases. 60 post-treatment dental casts which had attained good orthodontic treatment results were used in this study Many landmarks and linear measurement items to describe arch forms and dimensions were determined and measured. With a computer system and digitizer, arch forms were described and linear measurement items were statistically analysed. The following results were obtained. 1. The average labial and lingual arch forms at the bracket level were obtained. 2. Arch forms were expressed by parabolic equations and coefficients of determination. 3. Arch widths were larger in male than in female. 4. There were statistical significances in upper intercanine width, upper interfirst molar width, upper intersecond molar height, lower intercanine width and lower interfirst molar width between both sexes (p<0.05, p<0.01). 5. Interfirst molar width differences between maxilla and mandible were 6.43mm in male and 6.05mm in female.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.298-307
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• 2022

This study, through the potential research variables constituting smartphine shopping utilization, affects to some extent the social relevance and rapid adaptability of technology according to the cognitive age level perceived by customers. Research hypotheses and research models were established and tested to verify the research results on how they affect brand loyalty within the segmented market to which they belong. The purpose of this study is as follows. First, it was verified through the degree of casual relationship between smartphone shopping usage and potential research variables of innovation, convenience, usefulness, and hedonism that compose it, on the cognitive age level. Second, according to the cognitive age level perceived by customers themselves, it was verified through the degree of casual relationship between the mediators of social relevance and technology quick adaptability. Third, the casual relationship between social relevance, technology quick adaptability, and brand loyalty was verified according to the cognitive age level. Fourth, a theoretical study was conducted on the conceptual and operational definitions of the research variables of the research model of this study.

• Journal of Chest Surgery
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• v.31 no.9
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• pp.837-844
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• 1998

Background: Adenosine is secreted by myocardial cells during myocardial ischemia or hypoxia. It has many beneficial effects on arrhythmias, myocardial ischemia, and reperfusion ischemia. Although many investigators have demonstrated that cardioplegia that includes adenosine shows protective effects in myocardial ischemia or reperfusion injury, reports of the optimal dose of adenosine in cardioplegic solutions vary. We reported the results of beneficial effects of single dosage(0.75 mg/Kg/min) adenosine by use of self-made Langendorff system. But it is uncertain that dosage was optimal. The objective of this study is to determine the optimal dose of adenosine in cardioplegic solutions. Material and Method: We used a self-made Langendorff system to evaluate the myocardial protective effect. Isolated rat hearts were subjected to 90 minutes of deep hypothermic arrest(15$^{\circ}C$) with modified St. Thomas' Hospital cardioplegia including adenosine. Myocardial adenosine levels were augmented during ischemia by providing exogenous adenosine in the cardioplegia. Three groups of hearts were studied: (1) group 1 (n=10) : adenosine - 0.5 mg/Kg/min, (2) group 2(n=10): adenosine -0.75 mg/Kg/min, (3) group 3 (n=10) : adenosine -1 mg/Kg/min. Result: Group 3 resulted in a significantly rapid arrest time of the heart beat(p<0.05) but significantly slow recovery time of the heart beat after reperfusion(p<0.05) compared to groups 1 and 2. Group 2 showed a better percentage of recovery(p<0.05) in systolic aortic pressure, aortic overflow volume, coronary flow volume, and cardiac output compared to groups 1 and 3. Group 1 showed a a better percentage of recovery(p<0.05) in the heart rate compared to the others. In biochemical study of drained reperfusates, CPK and lactic acid levels did not show significant differences in all of the groups. Conclusion: We concluded that group 2 [adenosine(0.75 mg/Kg/min) added to cardioplegia] has better recovery effects after reperfusion in myocardial ischemia and is the most appropriate dosage compared to group 1 and 3.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.3
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• pp.234-238
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• 2016

Purpose: Increasing use of computer aided design-computer aided manufacturing (CAD-CAM) system and number of design software made design of restoration easy and quick. Outcome of restoration has been dependent on dental technician's wax up proficiency, dentists can design restoration for themselves now. This study aims to investigate the outcome of restoration designs, according to handling skill of CAD-CAM design tool. Materials and methods: A patient's mandibular right 1st molar was prepared. After taking impression, stone model was made, scanned the stone model with 3 shape intra-oral scanner, stereolithography (STL) file was extracted. With 3shape dental designer, one dental technician with more than 5 years work experience (designer 0) and three dental technicians with less than 2years work experience (designer 1, 2, 3-group DT) and 4 1st year residents (designer 4, 5, 6, 7-group RT) designed gold crown on the same STL file. Designed crown's MD (mesio-distal) and BL (bucco-lingual) diameter, height of crown, inter-cuspal distance, number of occlusal contact points were compared. Statistical analysis was carried out, test of normality within each group, using independent t-test. Number of contact points were compared, using Wilcoxon signed-rank test. Results: There was no significant difference between group DT and group RT. Number of contact points also resulted in no significant difference. Conclusion: The outcome of each designed crowns showed no statistical differences, in values which can be expressed as numbers. Subjective factors were different. With increasing proficiency in handling designing software, fabrication of restorations according to each designer's occlusal concept can be made easy.

• Journal of Distribution Research
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• v.12 no.4
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• pp.27-47
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• 2007

Using survey data and the Heckit model that adequately controls the sample selection bias, we analyze shoppers expenditure through two major emerging shopping channels: Internet shopping and TV home shopping channels. Age, Internet experience, daily Internet usage, the number of computers are factors that affect the ratio of consumers' expenditure through Internet shopping relative to the expenditure through TV home shopping. Shopping frequency which represents the shoppers' incentives to reduce transaction costs also has a positive effect on the proportion of shoppers' expenditure through the Internet shopping. Shoppers' perceptions of convenience, reliability, speed, and diversity are also shown to affect shoppers' relative expenditure ratio through Internet shopping. In contrast, shoppers' perception of prices does not seem to affect their purchasing behavior.

• The Journal of the Korea Contents Association
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• v.16 no.3
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• pp.760-770
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• 2016

This study analyzed the relationship between stress and academic attitude multicultural youth, and cope with stress social support, and to understand the relationship between the parameters of psychological Hi feeling, and for more efficient guidance Set the structural equation model for verifying the relationship between the factors that provide the basic data to verify the relationship between fit and Henin models through systematic analysis. The results of this study are as follows. First, we examined the difference between the factors of stress due to the demographic Henin multicultural youth. The difference between the stress corresponding to the average income of the grade and families was observed. However, differences in the stress in accordance with the residence period is significantly different from stress for participation in relationships between classes was observed. Second, the stress of multi cultural youth, psychological Hello feeling to cope with stress is sound had the effect of (-). However, social support, stress coping, that there is an effect of the parameters of the positive (+) revealed the relationship between the both of psychological Hello feeling of stress and academic attitude.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.233-233
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• 2011

필요한 수자원을 추가확보하기 위한 댐 건설이 갈수록 어려워짐에 따라 이미 건설된 댐을 최대한 활용하는 과학적 저수지운영 방안이 필요하다. 또한 댐운영자가 쉽게 실무에 적용할 수 있는 방법이어야 한다. 본 연구의 목적은 댐관리자가 이해하기 쉽고 사용하기 쉬운 장기 저수지운영 방안을 개발하고자 하는 것이다. 수위구간별 저수지운영을 위한 운영률을 구성하고 이에 따른 순단위 저수지운영 모형을 구축하였다. 다변량 추계학적 모의발생기법을 사용하여 댐 유입량을 모의 발생하였다. 저수지운영의 수위구간을 결정하기 위한 최적화 방법으로 메타휴리스틱 방법으로 차원변화 탐색기법을 선정하였다. 안동댐의 단독운영을 위한 수위구간별 저수지운영률을 도출하여 저수지 모의운영을 수행하고 기존의 운영실적과 모의결과를 저수지운영 평가기준에 따라 비교하여 평가하였다. 안동댐의 단독운영 결과 모의된 저수위는 실적 저수위보다 전반적으로 높게 유지되었고, 모의 발전량이 실적 발전량보다 평균적으로 높음을 볼 수 있었다. 안동댐의 실적 발전량 평균값은 124.81 GWh이며, 모의결과의 발전량은 131.01 GWh이었다. 모의 발전량이 전반적으로 높은 이유는 방류량이 적은 상황에서 저수위를 높게 유지하여 발전효율을 높게 한 것이 주된 이유라고 사료된다. 안동댐의 실적과 모의 결과를 3 가지 저수지운영 평가기준으로 평가한 결과, 실패한 횟수는 실적이 554 회, 모의결과는 426 회이었다. 또한 2 순 연속하여 실패가 발생한 횟수는 각각 71회, 48 회이었고, 최대 연속 실패는 각각 52 순, 51 순이었다. 또한 총운영 기간에 대한 성공 횟수의 비율을 나타내는 신뢰도는 실적은 0.53, 모의된 결과는 0.64로 약 9 %의 차이를 보였다. 취약도는 실적이 $12.69\times10^6\;m^3$, 모의된 결과가 $5.14\times10^6\;m^3$로 $7.55\times10^6\;m^3$의 차이를 보였다. 회복도는 실적이 0.21, 모의 결과가 0.13으로 모의결과가 0.08 낮은 것으로 나타났다. 도출된 장기 저수지운영률을 안동댐의 단독운영에 적용한 결과 실적보다 본 연구에서 개발한 방법론에 의한 모의운영이 공급량, 발전량, 저수지 운영평가 통계량에서 나은 결과를 보였다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.1
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• pp.23-30
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• 2013

The fleet crew of Korea Coast Guard(KCG) have a wide range of roles to perform. It is already recognized that they carry dutie in inferior working conditions. Therefore, a research on leadership that concerns organizational effectiveness seemed necessary for them. This study examines whether transformational leadership style is appropriate in job satisfaction for the fleet crew of KCG. This study also proves the effect of a leadership style on job satisfaction by suggesting a hypothesis from preceding studies. In this study transformational leadership is fixed as independent variables and job satisfaction as dependent variables and six factors as demographic characteristics. It is found that Intellectual stimulation is the most influential factor, but individualized consideration is an uninfluential factor concerning job satisfaction.

• The Journal of the Korea Contents Association
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• v.19 no.12
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• pp.502-516
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• 2019

The objectives of this study were to understand the relationship between the self-leadership of clinical nurses, nursing organizational culture and nursing performance and identify factors influencing nursing performance. Data were collected from 242 nurses working at H hospital in A Metropolitan City. Data were gatherd collected from Oct 17 to Oct 23, 2016, and analyzed using SPSS 21.0 program. The analysis results showed that several demographic characteristics (i.e., age, marital status, educational level, position, clinical experience and clinical experience in the current department) significantly affected nursing performance. The results of hierarchical multiple regression analysis revealed that clinical experience in the current department and self-expectation are influencing factors in nursing performance and they explained 35.7% of the variance. In order to improve nursing performance, it is necessary to maintain the clinical experience in the current department and develop education programs for enhancing self-expectation of nurses.

• Journal of the Korean Data and Information Science Society
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• v.26 no.6
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• pp.1199-1206
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• 2015

into aging is the most rapidly increasing among the OECD countries. Consequently, this study aims at analyzing the forms of portfolio establishment by group, the factors affecting the old age preparation, and the presence of middle-aged households' preparation for the old ages in order to forestall social problems like the poverty ration of elderly that have been caused by the rapidly aging society. The result shows that the portfolio for the old age preparation can be expanded if a combination product of finance and real estate is developed as a means of old age preparation. Upon the results of the study above, it can be seen that the old age preparations differ according to not only the demographic elements, but also the extent to how much resources one holds. Especially, the various factors affecting the holding resources vary householder by household depending on whether they prepare for the old ages or not.