• 대한치과보철학회지
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• 제54권1호
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• pp.21-27
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• 2016

국소의치 수복에서는 의치 장착에 의한 잔존 조직의 위해를 최소한으로 억제하는 것이 중요하다. 잔존 구강조직에 위해를 가하는 첫 번째 요인은 잔존치 및 치조제의 기능력 부담이며 두 번째는 구강 위생관리 부족에 의한 영향이다. 이중관을 활용한 국소의치는 rigid support를 통해 치조제에 미치는 부담을 경감시킬 수 있으며, 외관과 의치부에 부착되는 치태 및 침착물을 구강 외에서 쉽고 확실하게 관리할 수 있다. 또한 내관인 지대치 역시 모든 방향에서 청소가 용이해 변연 치은의 건강에 유리하다. 본 증례에서는 심한 치조골 흡수 및 불량한 구강 위생관리를 보이는 부분 무치악 환자에서 이중관을 이용한 국소의치로 상, 하악을 수복하여 기능과 심미, 구강 위생 관리 측면에서 만족할 만한 결과를 얻을 수 있었다.

• 대한골관절종양학회지
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• 제4권1호
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• pp.22-29
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• 1998

A limb-sparing operation has a definitive role in the treatment of osteosarcoma in the lower extremity of skeletally-immature patients. After a limb-sparing operation, leg length discrepancy remains as a major disability that should be corrected. This study was designed to suggest methods of tumor resection and proper timing of leg length equalization in skeletally immature osteosarcoma patients. From September 1990 to January 1998, we reviewed eight osteosarcoma patients in an immature skeletal age. There were 4 males and 4 females, and their mean duration of follow-up was 50.37 months (range : 25 to 88 months). Mean skeletal age was 8 years (range : 8 months to 11 years). The patients were classified according to the methods of tumor resection ; intercalary resection in 1 case, transepiphyseal resection in 1, intra-articular resection in 5, and extra-articular resection in 1. The results were as follows ; 1. The leg lengthening was begun when a patient's leg length discrepancy reached 4-5cm. 2. The age of final lengthening with permanent reconstruction was 14 years in males and 12 years in females (about 2 years before skeletal maturity). 3. When reconstruction was performed with a temporary spacer, the site of lengthening Was in the soft tissue, not in bone, and then a permanant reconstruction was done. 4. Reconstruction with a biologic spacer to preserve the joint function was a reasonable method for equalization of leg length. In conclusion, the appropriate choice of reconstructive method and the age at which to correct the leg length discrepancy in a skeletally-immature osteosarcoma patients are important factors for maintaining leg length at full maturity.

• 한국융합학회논문지
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• 제8권4호
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• pp.101-109
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• 2017

본 연구는 대학생들의 감사성향과 주관적 안녕감이 스트레스 대처에 미치는 영향을 파악하기 위하여 시도하였다. 간호학과와 비간호과 학생 336명으로, 통계자료는 t-test, Pearson Correlation, Multiple regression으로 분석하였다. 간호학과 학생들이 비간호과 학생에 비하여 감사성향, 생활만족도, 적극적 스트레스 대처에 유의한 높은 점수를 나타내었다. 2학년이 1학년보다 감사성향, 주관적 행복감, 스트레스 대처에 높은 점수를 나타내었다. 감사성향은 주관적 안녕감, 스트레스 대처와 강한 상관관계를 나타내었다. 스트레스 대처에 주 영향 요인은 정적 정서와 감사성향으로 나타났다. 따라서 대학생들의 스트레스 대처능력을 향상시키기 위해서 교육과정이나 교과 외 활동 등 다양한 방법을 통하여 주관적 안녕감과 감사성향을 높여줄 수 있는 방안의 강화가 필요하다.

• 대한가정학회지
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• 제48권1호
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• pp.137-161
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• 2010

The aim of this study was to identify the most effective methods with which to revitalize Korean high school culinary education. To achieve this aim, a culinary recognition questionnaire survey of 616 students from 9 culinary high schools was carried out. The 9 surveyed schools represented the following of 7 regions: Chungnam, Busan, Incheon, Daegue, Jeonbuk, Gyeongbuk, and Gwangju. Collected data were subjected to descriptive analysis, $x^2$-test, t-test, and one-way ANOVA using SPSS(version 14.0). The results of this study are as follows. Culinary practice interest and learning demand of most students were high. 6.8% of students indicated that initial theory learning, followed by video education, and finally live demonstration is an effective teaching methodology. They preferred practicing on actual ingredients as the primary teaching and learning method, nominating technician cooking as the most favorite. As for areas needing improvement in culinary practice education, difficulties with material preparation and insufficient learning hours were identified as prominent factors by 66.8% of respondents. There was unanimous agreement that culinary practice education can be enhanced by highly skilled teachers, while interest for the discipline itself can be fostered by initiating and encouraging cooking participation in the home. Freshmen and special high school students suggested that a cooking related website is necessary to expand the current information interface, which is currently limited to colleagues and employers. In relation to culinary education revitalization, consistent promotion of departments, or high schools that have proven student satisfaction rates and effective culinary curriculum are required. Furthermore, teachers can also aid this process by more effective student pastoral care in order to improve school life satisfaction. However, teacher job satisfaction is an important component of this process, and better employment conditions and remuneration packages reflecting extra work must be considered as part of an attractive teacher-incentive employment policy.

• Journal of Information Processing Systems
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• 제8권3호
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• pp.495-520
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• 2012

A secure Electronic Payment System (EPS) is essential for the booming online shopping market. A successful EPS supports the transfer of electronic money and sensitive information with security, accuracy, and integrity between the seller and buyer over the Internet. SET, CyberCash, Paypal, and iKP are the most popular Credit Card-Based EPSs (CCBEPSs). Some CCBEPSs only use SSL to provide a secure communication channel. Hence, they only prevent "Man in the Middle" fraud but do not protect the sensitive cardholder information such as the credit card number from being passed onto the merchant, who may be unscrupulous. Other CCBEPSs use complex mechanisms such as cryptography, certificate authorities, etc. to fulfill the security schemes. However, factors such as ease of use for the cardholder and the implementation costs for each party are frequently overlooked. In this paper, we propose a Web service based new payment system, based on ANSI X9.59-2006 with extra features added on top of this standard. X9.59 is an Account Based Digital Signature (ABDS) and consumer-oriented payment system. It utilizes the existing financial network and financial messages to complete the payment process. However, there are a number of limitations in this standard. This research provides a solution to solve the limitations of X9.59 by adding a merchant authentication feature during the payment cycle without any addenda records to be added in the existing financial messages. We have conducted performance testing on the proposed system via a comparison with SET and X9.59 using simulation to analyze their levels of performance and security.

• Journal of Animal Science and Technology
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• 제57권8호
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• pp.27.1-27.6
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• 2015

This study was designed to investigate the effects of ${\alpha}$-tocopherol and granulosa cells monolayer on nuclear maturation and cleavage rates of ovine cumulus-oocyte complexes (COCs). The COCs (n = 2814) were matured in maturation medium supplemented with various concentration of ${\alpha}$-tocopherol (0, 5, 10, $15{\mu}g/ml$), oocytes were incubated at $39^{\circ}C$ with 5 % $CO_2$ for 24 h in three culture systems: (a) maturation medium (MM; n = 884), (b) co-cultured with granulosa cells (CG; n = 982) and (c) co-cultured with granulosa cells and cells were further cultured in MM for 12 h (CG + 12hMM; n = 948). Our results showed that ${\alpha}$-tocopherol had no effect on GVBD and MII as compared to control group, but when ${\alpha}$-tocopherol added to maturation medium the rate of cleavage decreased. This indicates interaction of above mentioned factors in any of the treatments showed no significant differences on the rate of maturation and cleavage stages (MII, GVBD and cleavage) (p > 0.05). The oocytes co-cultured with granulosa cells for 24 h had beneficial effects on cleavage rate. The maximum MII and cleavage rates were achieved when oocytes had extra 12 h culture in the maturation medium without granulosa cells. Results also showed our modified co-culture system (CG + 12hMM), improved rates of MII and the cleavage in comparison with other studied maturation systems.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제23권4호
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• pp.1043-1058
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• 2009

대학수학을 수강하는 2007학년도 2학기 충주대학교 1학년 학생 100명에게 개인별로(부록2)에서 세 문항, 그룹별(2명)로 (부록3)에서 두 문항씩 학기 초에 프로젝트를 부여하고 결과를 알아보고 분석하여 다음 프로젝트 과제 수행에 활용 자료로 삼도록 하였다. 프로젝트 수행을 통해서 학생들은 수학에 대한 사고 능력과 글쓰기 능력이 향상되었고 그룹 활동을 통해 협동심과 상호 협조적인 관계의 유지의 중요성을 깨달았으며, 이런 기회를 갖게 된 것을 대학생활의 보람으로 느끼게 되었다. 특히, 효과적인 그룹 프로젝트를 통한 수업이 되려면 1) 수강 학생 수는 20인 이내가 좋고, 2) 그룹 프로젝트는 2명에게 부여하는 것이 바람직하고, 3) 교수는 학생의 수준에 맞는 문제를 교재 이외에서 선정하고, 4) 문제는 흥미 있고, 긍정적이며, 도전적이어야 하며, 5) 각 그룹에게 한 문제만 주어져야 하고, 6) 그룹들은 충분한 참고자료를 준비해야 하며, 7) 그룹의 각 구성원은 수학과 협력학습의 필요성과 중요성을 인식해야 하고, 8) 학생들은 수학을 즐거운 마음으로 다루어야 하며, 9) 실생활에서 수학이 중요함을 일깨워 주고, 10) 프로젝트 수행에 적절한 기간이 2달은 되어야 한다.

• Journal of Power Electronics
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• 제19권5호
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• pp.1108-1121
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• 2019

The non-inverting buck-boost converter (NIBB) is a step-up and step-down DC-DC converter suitable for wide-input-voltage-range applications. However, when the input voltage is close to the output voltage, the NIBB needs to operate in the buck-boost mode, causing a significant efficiency reduction since all four switches operates in the PWM mode. Considering both the current stress limitation and the efficiency optimization, a novel design methodology for the optimal phase-shift modulation of a NIBB in the buck-boost mode is proposed in this paper. Since the four switches in the NIBB form two bridges, the shifted phase between the two bridges can serve as an extra degree of freedom for performance optimization. With general phase-shift modulation, the analytic current expressions for every duty ratio, shifted phase and input voltage are derived. Then with the two key factors in the NIBB, the converter efficiency and the switch current stress, taken into account, an objective function with constraints is derived. By optimizing the derived objective function over the full input voltage range, an offline design methodology for the optimal modulation scheme is proposed for efficiency optimization on the premise of current stress limitation. Finally, the designed optimal modulation scheme is implemented on a DSPs and the design methodology is verified with experimental results on a 300V-1.5kW NIBB prototype.

• 대한방사선기술학회지:방사선기술과학
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• 제44권1호
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• pp.53-58
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• 2021

Kerma Area Product (KAP) is best indicator of radiation monitoring on radiographic examinations. KAP can be measured differently depending on the X-ray irradiation area, air kerma, souce-skin distance, type of equipment, etc. The major factors are exposure area and the air krema. The KAP currently used only considers the exposure area with X-rays and has a problem that KAP is always excessively overestimated from the dose received by an actual subject. Therefore, in this study, in order to measure the accurate KAP, a new area dose calculation that can be calculated by dividing the area where the actual X-ray is irradiated is presented, and the KAP is the real area. We compared and analyzed how much it was overestimated compared to the dose. The Skull AP projection and seven other projection were compared and analyzed, and the KAP was overestimated in each test by 52% to 60%. In this way, the effective KAP (EKAP) calculation developed through this study should be utilized to prevent extra calculation of the existing KAP, and only the accurate patient subject area should be calculated to derive the accurate area dose value. EKAP is helpful for control the patient's exposure dose more finely, and it is useful for the quality control of medical radiation exposure.

• Journal of Periodontal and Implant Science
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• 제38권4호
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• pp.709-716
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• 2008

Purpose: Autogenous transplantation of teeth can be defined as transplantation of teeth from one site to another in the same individual, involving transfer of impacted or erupted teeth into extraction sites or surgically prepared sockets". Successful autogenous transplantation of teeth depends upon a complex variety of factors. Such factors include damage to the periodontal ligament of the donor tooth, residual bone height of the recipient site, extra-oral time of tooth during surgery. Schwartz and Andreasen previously reported that autogenous transplantation of teeth with incomplete root formation demonstrated higher success rate than that of teeth with complete root formation. Gault and Mejare yielded similar rate of successful autogenous transplantation both in teeth with complete root formation and in teeth with incomplete root formation when appropriate cases were selected. This case report was aimed at the clinical and radiographic view in autogenous transplantation of teeth with complete root formation. Materials and Methods: Patients who presented to the department of periodontics, Chonnam National University Hospital underwent autogenous transplantation of teeth. One patient had vertical root fracture in a upper right second molar and upper left third molar was transplanted. And another patient who needed orthodontic treatment had residual root due to caries on upper right first premolar. Upper right premolar was extracted and lower right second premolar was transplanted. Six months later, orthodontic force was applied. Results: 7 months or 11/2 year later, each patient had clinically shallow pocket depth and normal tooth mobility. Root resorption and bone loss were not observed in radiograph and function was maintained successfully. Conclusion: Autogenous transplantation is considered as a predictive procedure when it is performed for the appropriate indication and when maintenance is achieved through regular radiographic taking and follow-up.