• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1698-1711
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• 2022

A combined safety approach, which uses a best-estimate computer code and adopts conservative assumptions for safety systems availability, is developed and applied to the safety margin evaluation for the Loss of Condenser Vacuum (LOCV) of the 1000 MWe Korean Nuclear Power Plant. The Multi-dimensional Analysis of Reactor Safety-KINS standard (MARS-KS) code is selected as a best-estimate code and the PAPIRUS program is used to obtain different initial operational conditions through random sampling of control variables. During an LOCV event, fuel integrity is not threatened by the increase in Departure from Nuclear Boiling Ratio (DNBR). However, the high pressure in the primary coolant system and the secondary system might affect the system integrity. Thus, the peak pressure becomes a major safety concern. Transient analyses are performed for 124 cases of different initial conditions and the most conservative case, which results in the highest system pressure is selected. It is found the suggested methodology gives similar peak pressures when compared to those predicted from existing methodologies. The proposed approach is expected to minimize the time and efforts required to identify the conservative plant conditions in the existing conservative safety methodologies.

• 한국압력기기공학회 논문집
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• 제20권1호
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• pp.75-83
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• 2024

In this study, high temperature design and integrity evaluation methodology have been developed for Type 316L stainless steel air-to-sodium heat exchanger which uses 700℃ sodium as coolant. Currently the only design rules that take creep effects into consideration explicitly for the 316L stainless steel subjected to high temperature in the creep range are French RCC-MRx, where elevated temperature designs are possible around 550℃. Absent design coefficients at high temperature were determined based on the material properties newly determined in previous studies, and high-temperature design evaluation methodologies were developed based on 3D finite element analyses on the 700℃ class heat exchanger. In addition, works were conducted on the web-based design evaluation program of HITEP_RCC-MRx including incorporation of material properties and design coefficients up to 700℃. Methodologies on high temperature design evaluations on Type 316L stainless steel high-temperature heat exchanger were suggested.

• Journal of Electrochemical Science and Technology
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• 제15권2호
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• pp.207-219
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• 2024

Metal-N-C (MNC) catalysts have been anticipated as promising candidates for oxygen reduction reaction (ORR) to achieve low-cost polymer electrolyte membrane fuel cells. The structure of the M-N_x moiety enabled a high catalytic activity that was not observed in previously reported transition metal nanoparticle-based catalysts. Despite progress in non-precious metal catalysts, the low density of active sites of MNCs, which resulted in lower single-cell performance than Pt/C, needs to be resolved for practical application. This review focused on the recent studies and methodologies aimed to overcome these limitations and develop an inexpensive catalyst with excellent activity and durability in an alkaline environment. It included the possibility of non-precious metals as active materials for ORR catalysts, starting from Co phthalocyanine as ORR catalyst and the development of methodologies (e.g., metal-coordinated N-containing polymers, metal-organic frameworks) to form active sites, M-N_x moieties. Thereafter, the motivation, procedures, and progress of the latest research on the design of catalyst morphology for improved mass transport ability and active site engineering that allowed the promoted ORR kinetics were discussed.

• Bulletin of the Korean Chemical Society
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• 제33권5호
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• pp.1577-1580
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• 2012

The orientational and dynamic behavior of liquid crystal molecules on the alignment layer surfaces of liquid crystal display (LCD) devices is crucial to their performance, but there are only a few methods of experimentally elucidating the interactions between the liquid crystals and the alignment layers. Inspired by the natural and technical similarities between membrane proteins in lipid bilayers and liquid crystals in LCDs, we employed solid-state NMR methodologies originally developed for the study of membrane proteins in lipid bilayers for the in-situ analysis of liquid crystal display panels. In this article, we present a home-built 500 MHz narrowbore (NB) The orientational and dynamic behavior of liquid crystal molecules on the alignment layer surfaces of liquid crystal display (LCD) devices is crucial to their performance, but there are only a few methods of experimentally elucidating the interactions between the liquid crystals and the alignment layers. Inspired by the natural and technical similarities between membrane proteins in lipid bilayers and liquid crystals in LCDs, we employed solid-state NMR methodologies originally developed for the study of membrane proteins in lipid bilayers for the in-situ analysis of liquid crystal display panels. In this article, we present a home-built 500 MHz narrowbore (NB) $^{19}F-^{13}C$ double resonance solid-state NMR probe with a flat-square coil and the first application of this probe for the in-situ analysis of LCD panel samples. double resonance solid-state NMR probe with a flat-square coil and the first application of this probe for the in-situ analysis of LCD panel samples.

• 한국지반공학회논문집
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• 제33권9호
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• pp.35-47
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• 2017

최근 3차원 지하공간통합지도 구축 사업과 더불어 지반정보를 3차원으로 가시화하는 연구가 진행 중에 있다. 이러한 지반정보의 3차원 가시화를 위해서는 우선적으로 지반정보의 정밀도를 분석하여 검증 할 필요가 있다. 2013~2014년은 수집 DB에 대한 정밀도를 검증하는 연구가 진행되었으며, 최근 지반정보의 3차원 구축을 위한 기초자료 제시의 일환으로 지반정보의 정밀도를 분석하는 연구가 진행되었다. 이러한 연구들에서 더 나아가 본 연구에서는 시추정보의 정밀도 향상 방안 및 지층 모델링을 위한 지반정보의 활용 방안을 제시하여 신뢰성 있는 3차원 지반정보의 구축 방안을 제시하고자한다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1425-1432
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• 2011

The various risk assessment methodologies have been introduced in the railway industries. The risk assessment suggested by CENELEC are described with two ways; quantitative and qualitative methods. However, in the industry application level, the quantitative method is hard to apply for a project because of somehow complicated or few statistical figures which was driven from the on-site and the qualitative method is too subject to have the confidence of its results fully. In this paper, the state-of-the-art methods which were suggested in Europe recently are introduced and compared to existing quantitative and qualitative methods. Furthermore, the application measures of railway projects are investigated.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2003년도 학술대회지
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• pp.500-503
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• 2003

현재, 국내 건설업에서 공정과 공사비 정보를 통합관리할 수 있는 공정${\cdot}$공사비 통합관리시스템(EVMS)의 필요성이 제기되고 있으며, 일정규모 이상의 대형건설공사에 적용될 예정이다. 본 연구에서는 EVNS의 효율성 증진을 위한 공사분류체계(WBS)를 연계하는 방법론을 제안하고 있으며, 또한 실무활용성을 극대화하기 위해 방법론 기초한 웹기반 공정${\cdot}$공사비 통합관리시스템의 시안을 구축하였다.

• 품질경영학회지
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• 제33권3호
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• pp.105-113
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• 2005

Six sigma has been the most influential management innovation program in a number of leading companies and its application has extended beyond manufacturing processes. Most companies have taken company-wide six sigma initiatives to also improve transactional and R&D processes. However, due to the limitation of existing methodologies, numerous difficulties arise during the six sigma application to non-manufacturing processes. In this study, a modified six sigma framework is proposed to facilitate six sigma implementation to transactional processes. The newly developed framework is applied to a six sigma project of the new product launching process of a marketing area.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2003년도 추계종합학술대회 논문집
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• pp.157-160
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• 2003

웹 서비스는 WSDL 서비스 인터페이스와 서비스 구현 문서를 이용하여 정적으로 호출되거나 서비스타입 정의와 UDDI를 통한 서비스 구현을 검색함으로서 동적으로 호출될 수 있다. 지금까지는 동시에 두 가지를 수행 할 수 없었다. 본 논문에서는 Model View Controller(MVC) 프레임워크를 사용한 정적/동적 웹 서비스를 지원하는 효율적인 멀티미디어 CMS(Contents Management Systems)를 설계하고 구현하였다.

• 한국IT서비스학회지
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• 제5권2호
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• pp.199-210
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• 2006

Most of the known RFID applications are derived from RFID technology and its functionalities not business analysis or requirements, so that companies may not obtain real competitive edges by implementing RFID application systems. Developing successful RFID applications is one of the key elements for prevailing RFID use by industries. Research objective is to propose an effective methodology for developing RFID applications based on analyzing business processes. The approach is designed to figure out both technical and business requirements related to RFID applications based on BPR (Business process reengineering) and ISP (Information strategy planning) methodologies. To verify the effectiveness of our approach, we applied the proposed approach to real field cases. As RFID technologies get flourished, the proposed approach is expected to play a meaningful role as an effective tool for developing new RFID applications.