• 항공우주기술
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• 제9권2호
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• pp.14-21
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• 2010

이온추력기는 전기추력기의 일종으로 높은 추력을 내기가 힘든 단점이 있으나 상대적으로 매우 높은 비추력을 낼 수 있는 장점이 있기 때문에 장거리 혹은 장시간의 우주비행이 요구되는 미션을 위해 활용되는 우주추진기관이다. 최근에 들어 우주탐사에 대한 세계 각국의 관심이 높아져 가고 있고 기존의 미국, 러시아, 유럽 이외에도 일본, 중국, 인도 등이 우주탐사에 나서고 있다. 소행성탐사나 외행성탐사와 같은 장거리 임무의 경우에는 화학식 추력기만을 사용하는 경우 과도한 추진제 적재로 인해 발사 중량이 증가하는 단점이 있어 최근에 들어서는 화학식 추력기와 이온추력기를 조합하여 사용하는 것이 세계적인 추세이다. 본 논문에서는 이온추력기 개발을 위해 수행된 이온화 방식 및 제작 기술과 관련된 연구의 수행 내역과 이온추력기 기본 모델의 제작 결과 및 방전 시험 결과를 소개하였다.

• 대한영양사협회학술지
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• 제10권4호
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• pp.428-441
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• 2004

This study focused on developing and assessing the effectiveness of maternal and child nutrition education materials that can be used conveniently at health centers. Focus group interviews with pregnant women, research of websites for pregnant women, and questionnaire-based surveys on community residents' needs for maternal and child nutrition services were conducted as preliminary study. The focus group interviews were conducted ten times, with five or six women, and the needs assessment was carried out on 884 pregnant or lactating women. The contents of the education materials developed based on the preliminary study were made up of the pregnant women section and the lactating women section. The entire material was composed of lecture materials, guidelines for educators, and handout materials for mothers, in the form of CD and booklets. The lecture materials were made using MS Power Point and the guidelines were wrote specifically, including basic information, main points to the lectures, and lesson plans, so that even non-professionals can easily use them. The effectiveness of the education materials was assessed based on a pretest and posttest method. The reliability of the test instrument was measured by Cronbach alpha, which was 0.75. The results were that the participants' nutrition knowledge scores showed a significant increase(p<0.05) from 3.79$\pm$0.33 to 3.96$\pm$0.34, and their attitudes changed positively after the education (p<0.05).

• 가정과삶의질연구
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• 제34권5호
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• pp.53-68
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• 2016

Financial preparation for retirement means making financial plans by predicting expected incomes and expenditures needed for maintaining success in later life. Because this preparation needs long-term planning, preparing as early as possible is recommended. This study, therefore, uses theory of planned behavior for examining the intention of financial preparation for retirement of consumers in their 20s and 30s. By using financial education and its understanding as additional variables, this study also intends to examine the ultimate effects on the intention. The following is a summary of the main results and suggestions. First, the level of consumer financial education is lower than the average. The level of understanding finance is lower than the average, and particularly, the level of understanding retirement related finance is much lower. Second, the more the attitude of financial preparation for retirement is positive, and the higher the level of subjective norm or perceived behavioral control is, the level of the intention of financial preparation for retirement tends to be more higher. Therefore, relevant efforts to encourage this preparation are needed. Third, the level of the intention of financial preparation for retirement is higher than the average, whereas financial education has no effects on the intention. This means that despite the importance of the financial education, its current implementation has many problems. The suggestions of this study are as follows. First of all, this study can provide preliminary data for developing retirement planning programs. In addition, in terms of the policy, given that this study targets relatively young consumers in their 20s and 30s, it can provide preliminary data for making policies for their future retirements.

• Nuclear Engineering and Technology
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• 제51권4호
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• pp.1098-1108
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• 2019

Korea's first commercial nuclear power plant at Kori site was permanently shut down in 2017 and is currently in transition stage. Preparatory activities for decommissioning such as historical site assessment, characterization, and dismantling design are being actively carried out for successful D&D (Dismantling and Decontamination) at Kori site. The ultimate goal of decommissioning will be to ensure the safety of workers and residents that may arise during the decommissioning of nuclear facilities and, thereby finally returning the site to its original status in accordance with the release criteria. Upon completion of decommissioning, the resident's safety at a site released will be assessed from the evaluation of dose caused by radionuclides expected to be present or detected at the site. Although the U.S. commercial nuclear power plants with decommissioning experience use different site release criteria, most of them are 0.25 mSv/y. In Korea, both the unrestricted and restricted release criteria have been set to 0.1 mSv/y by the Nuclear Safety and Security Commission. However, since the dose is difficult to measure, measurable concentration guideline levels for residual radionuclides that result in dose equivalent to the site release criteria should be derived. For this derivation, site reuse scenario, selection of potential radionuclides, and systematic methodology should be developed in planning stage of Kori site decommissioning. In this paper, for calculation of a preliminary site-specific Derived Concentration Guideline Levels (DCGLs) for the Nuclear Power Plant site, a novel approach has been developed which can fully reflect practical reuse plans of the Kori site by taking into account multiple site reuse scenarios sequentially, thereby striking a remarkable distinction with conventional approaches which considers only a single site scenario.

• 문화기술의 융합
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• 제9권2호
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• pp.127-132
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• 2023

정보통신기술의 급속한 발달과 진보는 교육 분야의 변화를 가져오고 있으며 코로나-19 팬데믹을 기점으로 교수-학습에 있어 혁신적인 방법들이 소개되고 실제로 현장에서 많이 적용되기 시작하였다. 이러한 경향을 반영하여 본 연구는 코로나-19 이후 교육현장에서 널리 활용되는 에듀테크 활용에 대한 예비초등교사들의 인식을 살펴보는 그 목적이 있다. 이를 위하여 K교육대학교에서 실시한 에듀테크 활용 경진대회에서 선정된 주요 아이디어 7편과 2인의 예비교사를 대상으로 실시한 포커스그룹 인터뷰의 결과를 분석해 보았다. 분석결과 예비초등교사들은 에듀테크 기반 수업에 대한 필요성과 중요성에 대하여 공감하며, 아울러 에듀테크 기반 수업에 대한 교육적 효과에 대해서도 긍정적으로 인식하고 있음을 확인할 수 있었다. 결과를 종합해 보면 에듀테크 활용 수업은 교육부의 정책 및 계획과도 연계성을 갖추며 있으며 교육과정이 정한 목표를 달성함과 동시에 미래 학습자들을 효과적으로 지도하는데 중요한 기여를 할 것으로 예측할 수 있었다.

• Radiation Oncology Journal
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• 제34권1호
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• pp.26-33
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• 2016

Purpose: To compare the dose distribution between carotid sparing intensity modulated radiotherapy (IMRT) and opposed lateral field technique (LAFT), and to determine the effects of carotid sparing IMRT in early glottic cancer patients who have risk factors for atherosclerosis. Materials and Methods: Ten early glottic cancer patients were treated with carotid sparing IMRT. For each patient, the conventional LAFT plan was developed for comparison. IMRT and LAFT plans were compared in terms of planning target volume (PTV) coverage, conformity index, homogeneity index, and the doses to planning organ at risk volume (PRV) for carotid arteries, spinal cord and pharyngeal constrictor muscle. Results: Recurrence was not observed in any patients during the follow-up period. $V_{95%}$ for PTV showed no significant difference between IMRT and LAFT plans, while $V_{100%}$ was significantly higher in the IMRT plan (95.5% vs. 94.6%, p = 0.005). The homogeneity index (11.6%) and conformity index (1.4) in the IMRT plan were significantly better than those in the LAFT plans (8.5% and 5.1, respectively) (p = 0.005). The median $V_{5Gy}$ (90.0%), $V_{25Gy}$ (13.5%), and $V_{50Gy}$ (0%) for carotid artery PRV in the IMRT plan were significantly lower than those in the LAFT plan (99.1%, 89.0%, and 77.3%, respectively) (p = 0.005). Conclusion: Our study suggests that carotid sparing IMRT can significantly decrease the dose to carotid arteries compared to LAFT, and it would be considered for early glottic cancer patient with high risk of atherosclerosis.

• 한국건설관리학회논문집
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• 제13권4호
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• pp.33-47
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• 2012

서울시내 공동주택 가운데 사용연수가 15년을 초과하여 리모델링이 가능한 공동주택은 약 54.8만 세대로 서울시 공동주택의 42%에 달하고 있으며, 2015년까지 리모델링이 가능한 공동주택은 약 80만 세대에 달할 것으로 예상된다. 공동주택의 노후화를 개선하고 거주환경을 향상시키기 위한 유지보수 사업은 재건축 사업과 리모델링 사업으로 분류할 수 있다. 현재 정부의 재건축 규제로 인해 증축 리모델링이 공동주택의 유지 보수 사업의 대안으로써 주목받고 있으나 증축 리모델링을 추진하는 공동주택의 75%가 사업 초기단계에 머물러 있으며, 증축 리모델링 사업은 활성화되지 못하고 있는 실정이다. 따라서 본 연구에서는 증축 리모델링 전문가들을 대상으로 한 델파이 분석을 통해 증축 리모델링의 활성화를 저해하는 주요 요인과 영향도를 분석하고, 각각의 저해 요인을 해결하기 위한 방안을 제시하고자 한다.

• 한국생활과학회지
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• 제21권5호
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• pp.875-888
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• 2012

This study seeks to determine children's poem composition through an activity-based nature experiencing program and how it affects their language expression and peer interaction. This research also seeks to provide preliminary data for producing more effective lecturing and learning plans. The forty participants in the study included twenty 5-year-old children from E kindergarten and 20 5-year-old children from G kindergarten in N city. The results of the study demonstrated that children in the experimental group who experienced the poem composing activity with the nature experiencing program demonstrated a positive effect in terms of the quality of language expression as well as peer interaction. These results indicate that children's poem composing activity done with nature experiencing program could be used as a new lecture and learning method for the development of language expression and peer interaction in early childhood education.

• 천문학회보
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• 제39권2호
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• pp.113.2-113.2
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• 2014

Methanol masers are divided into two classes, I and II. Class II methanol masers trace the disk-outflow systems of massive young stellar objects (YSOs), while class I methanol masers appear to trace the interaction regions of outflows with the ambient molecular gas. Class II masers have been extensively studied by single dishes, connected arrays, and VLBIs. Meanwhile, class I masers have been much less studied. They have not been detected by any VLBI facility. Thus they have been believed to have more extended structures than class II masers. We made fringe surveys of 44GHz class I methanol maser emission towards more than 150 massive YSOs with flux densities >10 Jy using the Korean VLBI Network (KVN), and detected fringes in ~10% of the sources. We performed follow-up imaging observations of the detected maser sources with KVN and KVN+VERA (KaVA). The observations aim to investigate the distribution and kinematics of 44GHz methanol maser features in each source at milli-arcsecond resolutions, and to understand what they trace. In this talk we will present the fringe survey and imaging results and our plans for further studies. Additionally, we will also introduce the preliminary results of single-dish polarization observations of water and class I methanol masers.

• 한국디지털건축인테리어학회논문집
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• 제13권4호
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• pp.69-76
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• 2013

As the energy consumed in building area has occupied a lot when looking into energy usage weights in area over the world, energy reduction building, eco-friendly architecture comes to the fore in the modern architecture. Discussions on the eco-friendly architecture have various concept definitions and targets to be achieved.The architectural works of Norman Foster are expressed as high-tech buildings using iron, glass, etc. in appearance, but they appear as those buildings with low energy load by analyzing environmental conditions from initial design stage that each building has, utilizing natural energy with design of outer shell and applying proper technical system. Thus, this study aims at providing basic data of outer shell planning through eco-friendly element technologies by considering pattern and outer shell design of buildings, principles of eco-friendly building plan as an eco-friendly building planning technique of Norman Foster as an example of plans to utilize building pattern, outer shell design and natural environments, in order to utilize passive measures as much as possible to increase energy saving methods and increase comfort by analyzing element technologies in the eco-friendly architecture in line with the modern flow.