• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.446-446
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• 2009

표면 패시베이션 기술로 이용되는 수소화된 실리콘 질화막은 제조원가의 절감을 위한 실리콘 기판재료의 두께 감소에 따른 특성상의 문제점을 해결하기 위해 중요한 영향을 미치는 요소이다. 실리콘 질화막은 강한 기계적 강도, 우수한 유전적 특성, 수문에 의한 부식과 유동적 이온에 대한 우수한 저항력 때문에, 반도체 소자 산업에서 널리 사용되고 있다. 수소화된 실리콘 질화막은 반사방지 특성과 함께 표면 패시베이션의 질을 향상시킬 수 있다. 굴절률 1.9 ~ 2.3 범위에서 쉽게 변화 가능한 수소화된 실리콘 질화막은 굴절률 1.4 ~ 1.5 사이의 열적 산화막 보다 효과적인 반사방지막이다. 수소화된 실리콘 질화막을 사용한 태양전지에서는 효율을 높이기 위해서 기판 표면에서의 케리어 재결합이 억제되어져야한다. 또한, 수소화된 실리콘 질화막은 최적화된 두께와 굴절률을 가져야한다. 본 연구에서는 고효율 태양전지에 적용하기 위해 반송자 수명이 향상된 수소화된 실리콘 질화막을 플라즈마 화학 기상 증착법을 이용하여 증착하였다. 박막은 $250^{\circ}C\;{\sim}\;450^{\circ}C$에서 증착되었으며 증착된 박막은 1.94 to 2.05 굴절률 값을 가지고 있다. 반송자 수명을 증가시키기 위해 $650^{\circ}C\;{\sim}\;950^{\circ}C$에서 어닐링 하였고 반송자 수명을 측정하여 패시베이션 특성을 분석하였다. 수소화된 실리콘 질화막은 $850^{\circ}C$의 어닐링 온도와 굴절률 2.0 조건에서 가장 좋은 반송자 수명을 나타냈다.

• Journal of Engineering Education Research
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• v.7 no.4
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• pp.32-37
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• 2004

Well organized design based education is the one of the best way to develop the abilities needed for the engineer such as the recognizing and formulating a problem and then solving it creatively and systematically. In order for this, we prepared a course named 'Introduction to the Engineering Design' for the first-year students, which aims at developing creativity and ability to promote a project. Experiment-design mixed courses and theory-design mixed courses, where students have to solve various design problems, are provided for the higher grade students. In this paper, we are focused on the experiment-design mixed course for the second-year students which has been operating from two years ago. Here we show how the teamwork ability is improved. We also present how to operate the course in detail so that anyone can easily get the way to reach the outcomes needed for the engineers.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.11
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• pp.1201-1206
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• 2014

This paper presents the development of an event-based operator model of a wheel loader for virtual V-pattern working. The objective of this study is to analyze the performance and dynamic behavior of the wheel loader for a typical V-pattern. The proposed typical V-pattern working is divided into four stages. The developed operator model is based on eight events, and the operator's inputs are occurred sequentially by event. A 3D dynamic simulation model of the wheel loader is developed and used to analyze the dynamic behavior during working, and the simulation results are compared with the experimental data of V-pattern working. The proposed 3D dynamic simulation model and operator model are constructed using MATLAB/Simulink. The proposed operator model for V-pattern working is expected to enable evaluation of the working performance and dynamic behavior of the wheel loader.

• Korean Journal of Acupuncture
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• v.29 no.2
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• pp.224-238
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• 2012

Objectives : From mechanism studies using animal models to high-level evidence based research such as randomized controlled trials or systematic reviews, various acupuncture studies have been performed. Nevertheless, the current research appears insufficient to satisfy clinicians' needs. We aimed at investigating clinicians' perception on the translational research and suggesting ways of symbiosis between basic research and clinical practice. Methods : Data were collected using a web-based questionnaire made available to Korean medicine doctors who were informed through social networking service or e-mail. The survey participants indicated their awareness of acupuncture research and their thoughts on the applicability of research in practice. Results : Forty-seven clinicians completed the survey. While most respondents agreed that acupuncture research is very important, only 40% of them answered that the results of acupuncture research are useful to their own practice. In more than half of those who responded to the survey, the current acupuncture research is not viewed as reflecting clinical practice very much. Respondents agreed that acupuncture research should be based on clinical practice, and they recognized the need to collect valid clinical data from real-world practice. Also, as many as 77% of clinicians had no scruple to participate in research programs. Conclusions : There is no doubt among practitioners that acupuncture research is necessary. More importantly, practice-based research remains essential in order to feed-back research outcomes to clinical practice. Communications and academic exchanges between clinicians and researchers can mutually benefit research and practice with better information, resulting in symbiosis.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.5
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• pp.428-437
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• 2008

e-AIRS, an abbreviation of ‘e-Aerospace Integrated Research System’, is a virtual organization designed to support the aerospace engineering processes in the e-Science environment. As the first step toward a virtual aerospace engineering organization, the e-AIRS intends to give a full support to aerodynamic research processes. Currently, the e-AIRS can handle both the computational and experimental aerodynamic researches on the e-Science infrastructure. In detail, users can conduct the full CFD(Computational Fluid Dynamics) research processes, request wind tunnel experiments, perform the comparative analysis between computational and experimental resultants and finally collaborate with other researchers using the web portal. The current paper will describe those functions and the internal architecture of the e-AIRS system.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.16 no.2
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• pp.89-94
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• 2013

Purpose: The aim of this study was to evaluate the prevalence of increased aminotransferase levels and to identify associated factors in children admitted to hospital with urinary tract infections (UTIs). Methods: The study included children with a diagnosis of UTI who were admitted to the Konyang University Hospital from January 2007 to May 2011. The total number of patients was 249 and the mean age was $15.88{\pm}28.21$ months. UTI was defined as a positive urine culture (> $10^5$/colony forming unit [CFU]) with pyrexia. Patients were treated by intravenous antibiotics, such as ampicillin/sulbactam, aminoglycoside, cephalosporins or vancomycin. Patients with neonatal jaundice or other liver disease were excluded. We investigated the relationship of aminotransferase levels with the type of antibiotic, degree of vesicoureteral reflux (VUR), and causative organisms. Results: Children with increased aminotransferase levels were younger than those with normal levels (p=0.001), but white blood cell count, platelet count, causative organisms, type of antibiotics and presence of VUR were not associated with aminotransferase levels. Aminotransferase levels became normal within 1 month after discharge without special measures, except in 1 case. Conclusion: We found that many children with UTI have abnormal aminotransferase levels. In most cases, this change is mild and self-limiting. We conclude that increased aminotransferase level increase during UTI do not require unnecessary tests and excessive treatment.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.1 s.190
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• pp.110-117
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• 2007

This study investigated changes of mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae of the ovariectomised (OVX) rat. In previous researches, there were many studies for morphology of osteoporotic bones based on Micro-Computed Tomography (Micro-CT). However, there were few studies for detecting and tracking changes of mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae of the OVX rat. For this study, the 4th lumbar of the OVX rat (female Sprague-Dawley) was utilized as a specimen. An OVX rat was scanned at week 0 (just before surgery), at week 4, and week 8 after surgery. Micro-finite element (${\mu}-FE$) analysis was used to investigate mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae for an OVX rat. When the OVX rat (at week 8) was compared with the OVX rat (at week 0), the structural modulus of cortical and trabecualr bone was decreased by 52% and 99%, respectively. This study showed the change of mechanical characteristics of cortical bone as well as trabecular bone of an OVX rat. Detecting and tracking changes of mechanical characteristics could greatly contribute to an experiment test for the trabecular and cortical bone in the lumbar vertebrae of an OVX rat by using In-vivo Micro-CT.

• Korean Journal of Medicinal Crop Science
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• v.26 no.1
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• pp.32-41
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• 2018

Background: To obtain useful safflower resources for breeding and research of functional materials, the present study was conducted to determine fatty acid compositions and antioxidant activities of 281 safflower accessions collected from East Asia including South Korea. Methods and Results: Lipid contents and fatty acids compositions were evaluated using soxhlet extraction and gas chromatography, respectively. A antioxidant activities were analyzed using a spectrophotometer. The evaluation range of safflower accessions showed very wide variation. In terms of lipid contents, the China accessions were higher than the collection from other regions, whereas antioxidant activities did not differ among regions. The result of the principal component analysis showed that the first and second principal component cumulatively explained 90.6% of the total variation. In clustering the safflower accessions, the tree showed four major clades. Group II (16 accessions) was high in lipid content, oleic acid and linoleic acid, whereas group III (50 accessions) exhibited higher antioxidant activities than other groups. Conclusions: It was recommended that the China collections be utilized as a useful resource for research on functional oil materials. These results provided valuable information for safflower breeders and researchers of functional food.

• Journal of the Korean School Mathematics Society
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• v.15 no.3
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• pp.487-509
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• 2012

This study, in order to contribute to improvement of the affective domain for mathematics which is one of the largest issues of mathematics education, examined the background variables influencing mathematics anxiety of middle/high school students. As the result, the middle school students showed a greater level of anxiety than the high school students did, and especially the anxiety level according to environment factor and learning strategy factor was high. Also, male students showed overall a greater mathematics anxiety than female students did, and both group of students showed a higher anxiety level according to environment factor and learning strategy factor. Besides, the greater the time spent on private education was, the higher the mathematics anxiety level, and in test/performance factor, the group with low self-initiated learning time showed a higher level of mathematics anxiety compared to other two groups. Among four subfactors of mathematics anxiety test, the students overall scored lowest in anxiety for test/performance factor, and highest in environment factor.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.2
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• pp.198-204
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• 1994

Many old books concerning agriculture in ancient Korea were published during Yi dynasty, giving information on the agriculture of old and recent times, Present work describes the introduction of tobacco to Korea by reviewing old domestic or foreign agricultural literatures dealing with names of tobacco. Historically, tobacco had been called as many names such as Namcho, Yeoncho, Au, Seocho, Oecho, Hocho, Dampa Ko, Namkyongcho and Dampacke, and known to be introduced to Korea during early part of Kwanghwekun rule (year of 1618) from Japan. However, tobacco introduction from Japan to Korea seemed not be true by 2 historical facts. One is that at old time Japan had imported Chinese and Korean culture, and many crops during Nara and Heyan dynasties. The other is that there is no evidence of Japanese introduction found in Japan nowadays. The most plausible theory on tobacco introduction is that soldiers under General Youjung of Myong dynasty had brought tobacco to Korea during ImJinWaeRan(1592-1598). The above statements can be verified by old stories about Korean local tobacco varieties, and by letters Kim Dae Hyun(1553-1602) and General Youjoung.