• Korean Journal of Metals and Materials
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• v.50 no.8
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• pp.549-556
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• 2012

The tribological behavior of CrMoN films with respect to surface chemistry was investigated by using X-ray photoelectron spectroscopy (XPS). All of the films were prepared from a hybrid PVD system consisting of DC unbalanced magnetron (UBM) sputtering and arc ion plating (AIP) sources. The tribological property of the films was evaluated by a friction coefficient using a Ball-on-disk type tribometer. The chemistry of wear track was analyzed by energy dispersive spectroscopy (EDS) and XPS. The friction coefficient was measured to be 0.4 for the CrMoN film, which is lower than that of a monolithic CrN film. EDS and XPS results imply the formation of an oxide layer on the coating surface, which was identified as molybdenum oxide phases, known to be a solid lubricant during the wear test.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.295-299
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• 2022

In this paper, paint-free metallic plastic material, polypropylene (PP) and acrylonitrile styrene acrylate (ASA) materials were investigated on the applications for bumper skid plate and outside mirror housing parts. In order to maximize metallic effect, type, size and content of aluminum pigment were optimized based on flop index. Hybrid aluminum pigments with different aspect ratios were used to conceal weld lines. By controlling the fluidity of the material, the flow mark problem, generated on the surface of the part, was resolved. We also investigated the surface defects of flow and weld lines by using the developed modeling and simulation.

• 한국항공운항학회:학술대회논문집
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• 2015.11a
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• pp.277-281
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• 2015

시스템 엔지니어링은 현대사회에서 성공적인 프로젝트의 실현을 가능케 하는 하나의 개발 방법론으로 선진국에서는 정부, 공공기관, 방위산업체, 민수산업체 등에서 도입하여 시스템 개발 프로젝트를 전수명주기에 걸쳐 효율적이고 체계적으로 관리하고 있다. 시스템 검증 및 확인 프로세스는 시스템 엔지니어링의 핵심 요소 중의 하나로서 고객이 요구하는 시스템 요구사항들이 프로젝트 전수명주기에 걸쳐 올바르게 충족이 되었는가를 입증하고 확인하는 일련의 활동으로 구성된다. 본 논문에서는 국외의 연구 사례들을 조사하여 이러한 검증 및 확인 활동의 독립성이 시스템 개발 사업에 어떠한 긍정적인 효과를 발생시키는지를 분석하였다.

• Journal of the Korean Society of Systems Engineering
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• v.16 no.2
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• pp.141-147
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• 2020

Due to the nature of the long-term project of a Railway business, Many problems have been arisen in the process of delivering products or systems verified by suppliers to the customer's operation site. Unexpectedly, it is often necessary for the verified products to store intermediately at the supplier's site for a variety of reasons, such as delays in business and delays in civil engineering, at the time of sending them to the customer's operation site. In this study, the intermediate storage process for finding and solving problems related to intermediate storage was presented focusing on the Rolling Stock of Railway System by reference to ISO/IEC/IEEE 15288:2015. A suitable intermediate storage process based on the developed product or system's characteristics will allow the verified products or systems to be placed on the customer's operation site and to meet the customer's product or system requirements.

• Journal of the Korean Society of Systems Engineering
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• v.17 no.2
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• pp.106-113
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• 2021

Today, the market and customer requirements for safety-related products in the Railway industry are continuously increasing, and companies that supply these products continue to make related efforts. However, the international standard requirements for making safety-related products are high, so small and medium-sized business companies are having difficulty developing them due to problems in time and cost to achieve them. This study examined government-centered international certificate policies and cases and suggested improvement measures based on the research results. In addition to supporting international certification costs, the government needs to expand technical consulting and expert training for them to solve problems in obtaining an international certificate.

• Journal of the Korean Society of Systems Engineering
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• v.17 no.2
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• pp.114-121
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• 2021

Today, it is a time when self-help efforts are being made to increase the demand for international certification by domestic and foreign railway orderers and develop excellent railway systems for railway system and railway construction projects. Since 2011, cases of obtaining international certification related to the domestic railway system/products have been collected and analyzed through literature and Internet data and based on the analysis results, evaluation results on the acquisition of international certification in Korea are presented. Through these results, the government, research institutes, and industries will be practical reference materials for international certification-related work.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1998.10a
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• pp.377-380
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• 1998

방사능 핵폐기물 처분장 부지선정을 위해서는 암반의 특성화 작업이 선행되어야 한다. 특성화 작업이 선행되어야 한다. 특성화 작업은 암반은 열적, 역학적 및 수리적 거동 특성을 분석할 수 있는 수치모델을 개발하여, 국내 환경에 적합한 설계안을 조기에 설립할 수 있는 Program을 포함해야 한다. 이러한 목적을 달성하기 위한 초기단계로서, 현대엔지니어링 주식회사는 이 분야에 40년 이상의 경험과 기술을 축적하고 있는 세계적인 핵관련 연구소인 미국 샌디아 국립연구소 (Sandia National Laboratories)와 공동연구 등을 통해 서로간의 기술간의 기술을 공유하자는 "상호 기술협정(MOU)"을 '98년 5월 21일 맺었다. 본 연구는 이러한 취지하에 진행하고 있는 전체 Program의 일부로서 기본계획을 발포하여 향후 기술개발에 참여할 수 있는 산학연 협동체 구성 및 역할 분담을 통한 기초연구를 수행하고, 2000년 초반기에 한국에서 대구될 수 있는 처분장 처리문제를 미리 수행하려는데 일차적인 목적이 있다.적인 목적이 있다.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.616-620
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• 2015

본 연구의 목적은 홍수피해 잠재능 산정을 위하여 항목별 가중치 산정을 통한 계층화분석기법의 적용성을 평가하고자 한다. 홍수피해 잠재능 산정의 경우 유역의 특성에 따른 다양한 항목과 가중치를 적절하게 고려하여야 한다. 그러나 도시화 지역의 경우 외수력과 우수관 미설치에 대한 고려 없이 미리 정해진 절차에 의해 이루어지므로 실제 현장 조건을 정확하게 모사하지 못하고 있다. 따라서 위에서 언급한 것과 같이 두 가지 주요 항목을 홍수피해 잠재능 산정 절차에 반영하여 실제 상황을 보다 잘 모사하고 다양한 전문가 집단의 설문 결과를 반영하여 보다 정확한 판단을 하는 것이 필요하다. 연구결과 항목별 가중치 산정은 주요 항목의 가중치를 산정하는데 효과적인 것으로 나타났다. 또한 외수력과 우수관 설치를 고려한 수정 방법은 홍수피해 잠재능 산정에서 보다 좋은 결과를 제시하였다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.192-193
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• 2021

Recently, the need to strengthen the Air Environment Conservation Act and secure alternative heat sources during the winter by carbon neutrality policies has been raised. Accordingly, winter construction, which has safety and quality measures, is emerging as an essential factor. It is believed that eco-friendly tropical type electric hot air heaters will be able to solve most of the problems of winter construction at construction sites, especially prevention of suffocation and fire accidents. In addition, as a result of on-site performance verification, it has secured more than the same performance as the existing curing method, and the curing technology can create an eco-friendly and pleasant working environment while considering safety and construction.

• Journal of Space Technology and Applications
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• v.4 no.2
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• pp.105-120
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• 2024

The abilities of system engineering and project management (PM) are essential in the development of large instrumentations in modern astronomy. We propose a novel undergraduate educational program that allows students to gain experience in system engineering and PM by making a practical small spectrograph along with its test observation. A pilot program titled "Creative Astronomical Instrument Development and Observation" was conducted in Chungnam National University, as a part of the Space Expert Training Program of Ministry of Science and ICT during the Fall semester of 2023. After five teams were organized from 24 participating students, each team manufactured a spectrograph and observed spectra of the Sun, Moon, or planets with it. The development process was guided by several reviews, and students were evaluated based on the outcomes of their development processes and documentation. Through this program, students acquired fundamental principles of systems engineering and PM, as well as optical and mechanical engineering skills.