• 한국자동차공학회논문집
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• 제22권1호
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• pp.157-164
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• 2014

Dual fuel combustion strategy with di-methl ether (DME) and gasoline was tested in a compression ignition engine. Characteristics of combustion and emissions were analyzed with the variation of engine operating parameters such as fuel proportion, DME injection timing, intake oxygen concentration, DME injection pressure and so forth. Gasoline was injected into the intake manifold to form the homogeneous mixture with intake charge and DME was injected directly into the cylinder at the late compression stroke to ignite the homogeneous gasoline-air mixture. Dual fuel combustion strategy was advantageous in achievement of higher thermal efficiency and low NOx emission compared with DME single fuel combustion. Higher thermal efficiency was attributed to the lower heat tranfer loss from the decreased combustion temperature since the amount of lean premixed combustion was increased with the larger amount of gasoline proportion. Lower NOx emissions were also possible by lowering the combustion temperature.

• 농촌지도와개발
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• 제18권1호
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• pp.35-72
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• 2011

Study on children from international marriage so far has been conducted focusing on the school-aged children, and it uniformly presents those children as a mere being with problem, overlooking regional variables of rural area. Hence, this study aims to seek various means of adaptation of children from international marriage by considering both variables rural area and adolescence. For this study, six children from international marriage living in the rural area of H county in Jeonlanamdo were chosen, in-dept interview were conducted, and Giorgi(1985) was used to analyze qualitative data. The results shows that these adolescences appear to have extensive experiences in the areas of learning, personal relationship, home and identity. Level of academic achievement was influenced by what school they attend to, and personal relationship aspect was affected by prejudice and discriminative perception from people around them. In addition, in home environment, hatred toward father, sympathy for mother, comparison with mothers who have great cultural adaptation skills, and pressure as the firstborn appear to be on the increase. Adolescent children tend to be addicted to internet games in order to escape from anxiety, experiencing identity crisis. They tend to be negative about international marriage of their parents, and exhibit behaviors refusing values and religious view of their parents. At the conclusion, limitation of the study and suggestion for further study are presented.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1998년도 춘계학술대회논문집
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• pp.144-147
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• 1998

VCR is a back-up roll with a special contour which leads to the length of the contact line between back-up roll and work becones self adjustable in accordance with the width of the strip. The simulation of a finite element model and the on-line test at production mill demonstrate that the VCR roll may keep the crown of the roll gap relatively stable, and at same time, permit the rolling pressure to be adjusted over a wider range, and increase the effect of work roll bending on the roll gap. The VCR rolls have been successfully used at the first stands of two largest cold rolling mills in China, and on-line test has been done at a wide hot strip finishing train. The use of VCR roll has created favorable conditions for subsequent rolling passes and the achievement of better flatness quality.

• 가정과삶의질연구
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• 제28권1호
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• pp.87-98
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• 2010

The purpose of the present study was to examine the desire of married women to be re-employed and the factors related to this desire. The study gathered information from 240 women who gave up their jobs and careers after marriage. Information included their career history, current psycho-social condition, and family situation. Multiple regression and covariation structure analyses indicated that the desire of married women to go back to paid work was influenced by family economic condition, psycho-social condition, and child care situation. Specifically, the study found that family's monthly income and the age of the last child were negatively related to the women's desire for re-employment. On the other hand, economic pressure and achievement motivation were positively related to the women's desire. Finally, the study found that socio-economic background and external social support were not significantly related to the women’s wish to go back to the workforce.

• 한국의류산업학회지
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• 제10권6호
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• pp.1045-1050
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• 2008

Developing of high technology, productivity of the fiber product has being rapidly increased and also various kinds of advanced treatment process lead consumer's needs to more high functional, clean and healthy goods. Moreover, increasing in the concern of eco-friendly material and processing, it has been getting popular that the dyeing method like as using natural dyes is more eco-friendly and natural-friendly treatment process. The method, used in this study, adhesion by binding with micro-capsulized natural material to fabric has low change in quality by external influence and high ability in spray effect by broken capsule which comes to pressure and friction when it dressed. Also it has wide application from natural fiber to synthetic fiber. The purpose of this study is development of multi-functional synthetic material with micro-capsulized Scutellaria baicalensis on PET. Moreover, it was driven by comparison of colormetric properties and fastness between regular dip-dyeing method and binding with micro-capsulized material method. Dye ability was arranged mostly low exhaustion but the PET treated by micro-capsule was more or less better than the dip-dyeing PET. Through the SEM(Scanning Electron Microscope) of PET treated by micro-capsule, it has good residence of capsules even after 5 or 10 times washing. Wash and light fastness was arranged some different grade by each condition but mostly high achievement and the micro-capsulized PET was more improved than regular dip-dyed PET.

• 멤브레인
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• 제21권4호
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• pp.307-320
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• 2011

고분자 기체분리막은 막분리 공정에서도 가장 빠르게 발전하고 있는 분야이다. 고분자 기체 분리막 공정은 심냉법, 가압 기체 흡착법과 견주어 볼 때 경쟁력을 지니고 있다. 기체분리용 고분자 소재로는 폴리술폰, 폴리페닐렌옥사이드, 폴리카보네이트, 폴리이미드 등의 방향족 고분자들이 주로 사용되었다. 현재 이 중에서도 유리상 고분자인 폴리이미드의 경우 높은 투과도와 선택도를 달성하기 위해 많은 연구가 이루어지고 있다. 고분자 소재는 기체분리 성능에 많은 영향을 미치는 요인이기 때문에 기체분리용 고분자 소재와 구조에 대한 올바른 이해가 중요시되고 있다. 본 논문에서는 폴리이미드 제조 및 기체투과 특성에 대한 동향 및 개발 방향에 대해 확인하였다.

• 대한조선학회논문집
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• 제46권6호
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• pp.578-586
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• 2009

Recently, horn-type rudders are generally being used at high speed container ships and are frequently suffering from the cavitation occurs on the rudder surface in the vicinity of the gap between the horn and rudder plate. In the present study, a fluid supplying device is employed as to decrease the gap cavitation of the horn-type rudder. The device is devised to inject the water against the pressure side through the nozzle installed inside of the gap to control the gap flow. Numerical calculations are performed to investigate the effectiveness of the device and the results show that the device can noticeably reduce the gap cavitation. The rates of water injection for achievement of the maximum retardations of gap flow are also sought.

• 영재교육연구
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• 제14권2호
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• pp.1-18
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• 2004

본 연구는 1986년도에 한국과학기술대학 조기진학을 위해 1학년 과학영재들에게 초고속 속진학습을 동년 4월 1일부터 9월 26일까지 약 170여 일 동안 791 시간의 특별 프로그램을 투여하고 9월 입학시험에 응시한 8명의 대상자 중 설문에 응답한 6명의 학생들을 대상으로 하였다. 본 연구에서는 조기진학 특별 프로그램을 받은 과학영재들이 지난 17년 동안 어떤 과정을 거쳐 현재에 와 있는지를 알아보고, 17년 후 현재의 성취 정도를 파악하며, 자신이 받은 속진학습에 대해서 어떻게 평가하고 있는지에 대해 알아보고자 한다. 또한 그들은 자신의 성취의 요인을 무엇으로 보는지에 대해 알아보고, 이를 통하여 고교 과학영재의 초고속 속진학습의 가능성을 확인해보고 앞으로의 과학영재교육의 방향을 모색하고자 한다. 연구 결과 3명은 박사학위를 받고 연구소의 연구원, 교수로 성취하였고 나머지 3명은 석사학위를 받은 후 연구소의 연구원으로 근무하고 있었다. 이들의 연구업적은 분야에 따라 편차가 크나 연구업적이 큰 3명의 경우에는 25-28세에 SCI급 국제 저널에 논문을 낼 정도로 성취하였다. 특히 두 사람의 경우는 삼성그룹 기술논문경진대회 기게 화학분야 최우수상 수상, 국내 최초 IMT2000 상용 모뎀 칩 개발 등 두드러진 성과를 거두기도 하였다. 또한 한 명은 하버드 대학으로 대학을 옮겨 물리학을 전공하고, UCLA에서 법학을 전공하여 법대교수로 재직하고 있다. 자신이 받은 초고속 속진학습에 대한 평가에서 김덕영은 선행연구에서 고교과정 2년을 단축하는 특별 프로그램 운영은 필요한 것이고, 학습 성취는 물론 정서적 적응상태의 확인을 통해서 초고속 속진학습이 성공적이라고 주장하였다. 그러나 17년이 지난 지금 연구 대상자들의 반응은 긍정적인 면 보다는 부정적 시각이 많았다. 특히 조기진학을 위한 특별프로그램 참여자 중에서 첫 해에 합격한 학생들은 프로그램 참여가 자신감을 비롯한 인생에 긍정적인 영향을 미쳤다고 생각하나 불 합격생은 부정적인 영향을 미쳤다고 여기고 그 중에 한 명은 지금까지도 많이 후회하고 있다고 언급했다. 따라서 세심한 판별과정을 거쳐 능력 있는 과학영재를 조기에 발굴하여 체계적으로 속진교육을 한다면 과학영재들의 성취를 위해서 초고속 속진학습이 아닌 한속진학습은 반드시 필요하다. 앞으로 17년이 지난 후에 이들 과학영재들에 관한 종단연구는 다시 진행될 것이다.

• 대한임상검사과학회지
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• 제51권2호
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• pp.191-197
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• 2019

폐쇄성 수면 무호흡 환자들의 양압기 사용을 위한 적정 양압측정은 편리함과 경제성뿐만 아니라 다양한 원인으로 CPAP 측정법보다는 APAP 측정법을 더 선호한다. 그러나 PSG 감시하에 진행하는 CPAP 측정법보다 정확성에 대한 의문이 아직까지 남아있다. 이에 본 연구에서는 동일한 대상자에 대한 CPAP과 APAP 측정법의 적정 압력과 무호흡-저호흡 지수를 변수로서 두 방법간의 효율성과 정확성을 비교하였다. 대상자는 분할 수면다원검사 중 CPAP 양압 측정과 7일 이상 APAP 양압 측정에 성공한 79명이 모집되었다. CPAP과 APAP 측정법의 적정 양압은 $7.0{\pm}1.8cmH_2O$, $7.6{\pm}1.6cmH_2O$ 무호흡-저호흡 지수는 $1.3{\pm}1.5/h$, $3.0{\pm}1.7/h$로 CPAP 측정법이 두 변수 모두 통계적으로 유의하게 낮게 나타났다(P<0.001). 그러나 미국수면학회 가이드라인 무호흡-저호흡 지수 5/h이하의 적정 양압 도달 비율은 CPAP 측정법이 96.2% (76명), APAP 측정법이 94.9% (75명)으로 유의미한 차이를 보이지 않았다(r=-0.045, P=0.688). 본 연구를 요약하면, CPAP은 APAP 측정법보다 좀 더 효율적인 측정법으로 나타났다. 그렇지만 적정 양압에 도달하는 비율은 두 방법 모두 통계적 차이를 나타내지 않아 정확성을 가진다. 따라서 CPAP과 APAP 측정법 중 요구되는 상황에 따라 적절한 방법을 선택하여 적정 양압을 측정할 수 있겠다.

• Journal of Preventive Medicine and Public Health
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• 제44권1호
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• pp.56-64
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• 2011

Objectives: The purpose of this study was to estimate the prevalence and correlated factors of high myopia in 19 year-old men in Southeast Korea. Methods: This retrospective study was based on the medical checkup data of conscription during 2005. The study subjects were 19 years old men in Busan, Ulsan and Gyeongsangnam-do. The health checkup data of the conscripts consisted of noncycloplegic autorefraction test, the biometric data and social factors. To analyze the social and biometric effects, we classified the biometric factors into 4 or 5 groups and the social factors into 3 groups. High myopia was defined as a spherical equivalent of under -6.0 diopter. Data analysis was performed using the chi square test for trends and multiple logistic regression analysis. The SAS(version 9.1) program was used for all the analyses. Results: The prevalence of high myopia was 12.39% (6256 / 50 508). The factors correlated with high myopia were the residence area (OR, 2.07; 95% CI, 1.77 to 2.4 for small city; OR, 2.01; 95% CI, 1.72 to 2.34 for metropolis; the reference group was rural area), academic achievement (OR, 1.43; 95% CI, 1.34 to 1.53 for students of 4-and 6-year-course university; the reference group was high school graduates & under) and blood pressure (OR, 1.54; 95% CI, 1.10 to 2.16 for hypertension; OR, 1.09; 95% CI, 1.02 to 1.17 for prehypertension; OR, 1.10; 95% CI, 1.01 to 1.20 for hypotension; the reference group was normal blood pressure). Conclusions: More than one tenth of the young men were high myopia as one of the risk factor for visual loss. Further studies on high myopia and its complications are needed to improve eye health in Southeast Korea.