• 대한기계학회논문집B
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• 제37권8호
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• pp.781-788
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• 2013

엔진 설계시 실린더 주요 부품의 온도 분포 계산은 엔진 전체 구조안정성 평가시 열응력에 의한 변형을 고려하기 위해 필수적으로 수행된다. 최근 박용 및 발전용 중속엔진은 압축비 및 출력이 증대 되어 설계되고 있는 추세여서 증가된 연소실 열부하에 의한 영향을 고려하기 위해 열전달 해석의 높은 정확도가 요구되고 있다. 본 연구에서는 엔진 설계시 실린더 주요 부품의 온도 분포를 계산하고 계산된 온도 수준이 설계기준에 만족하는지를 정확히 평가 하기 위한 열전달 해석 프로세스를 정립하였다. 각 주요 열부하 영역의 경계조건 설정 과정을 1 차원 엔진 성능해석 및 3 차원 열유동 해석을 통하여 산출하여 적용하였으며 해석 결과는 해당엔진 모델의 프로토 타입엔진 주요 부품 온도를 계측하여 검증하였다.

• 대한치과기공학회지
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• 제25권1호
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• pp.173-185
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• 2003

This study mainly intends to determine the factors for which dental technicians are satisfied with their jobs and how much the resulting job transfer rate is and thus to identify the correlation between them. For these purpose, 200 subjects were sampled out of dental technicians in Seoul and Incheon, and the survey was performed from July 19, 2002 to August 15 (for 25 days) with self-administered questionnaire. Out of all collected questionnaires, 131 pieces(65.5%) were addressed for this study. As for the tools for this study, the structured questionnaire was used with its proven reliability and feasibility, and the contents of questionnaire consisted of 32 questions on the basis of related references. The contents of questionnaire were categorized into 3 sections: General attribute of subjects; Factors for which dental technicians are satisfied with their jobs; and their intention of job transfer. The questionnaire consisted of total 32 questions which included general attribute of subjects(10 questions), factors of their satisfaction with jobs(17 questions) and intention of job transfer(5 questions). The data analysis was processed by computerized system with SPSS(Statistical Package for Social Sciences). Statistical analysis techniques included frequency, percentage, T-test, F-test analysis and regression analysis. As a result of those analyses, the conclusion can be summarized as follows: 1. As a result of analyzing the factors for which the subjects were satisfied with their jobs, it was found that there were significant differences in career and job title out of question items(P<0.001). It was also shown that the factors of subjects' satisfaction averaged 3.43, which was considerably higher value than I expected. It was found that job and management factors were major job satisfaction factors. 2. As a result of analyzing the intention of subjects to decide their job transfer, it was found that there were significant differences in job title and marital status out of question items(P<0.001). It was shown that the total average of the intention of their job transfer amounted to 3.06. It was shown that dental technicians have relatively higher intention of job transfer from their current work place. 3. It was found that there was inverse correlation between the factors of subjects' satisfaction with their jobs and their intention of job transfer(r=-0.490, P<0.05). Likewise, it was also found that there was inverse correlation mostly between the evaluation value for each independent variable region in term of each factor of job satisfaction and the value for the intention of job transfer. In view of these correlations, it was concluded that higher job satisfaction likely led to lower job transfer. 4. As a result of regression analysis so as to determine the influences of job satisfaction factors on the intention of job transfer, it was found that the highest influential factor was management factor. And it was shown that the test values of model were statistically significant and its explanatory power amounted to 54.6%.