• 한국정밀공학회지
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• 제19권8호
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• pp.71-76
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• 2002

In this study low cycle fatigue (LCF) behavior of 12Cr steel at high temperature are described. Secondly, comparisons between predicted lives and experimental lives are made for the several sample life prediction models. Two minute hold period in either tension or compression reduce the number of cycles to failure by about a factor of two. Twenty minute hold periods in compression lead to shorter lives than 2 minute hold periods in compression. Experiments showed that life predictions from classical phenomenological models have limitations. More LCF experiments should be pursued to gain understanding of the physical damage mechanisms and to allow the development of physically-based models which can enhance the accuracy of the predictions of components. From a design point-of-view, life prediction has been judged acceptable for these particular loading conditions but extrapolations to thermo-mechanical fatigue loading, for example, require more sophisticated models including physical damage mechanisms.

• Membrane and Water Treatment
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• 제11권3호
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• pp.173-177
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• 2020

Wastewater treatment plants (WWTPs) have been recognized as one of the significant greenhouse gas (GHG) generators, due to the complex biochemical reaction and huge consumption of energy and materials. Recently, WWTPs have been built underground and they will be confronted with the challenges of mitigating GHG emissions and improving the quality of treated wastewater. Here, we focus on estimating GHG emissions to set up effective management plans for a WWTP built underground. First, we apply the process-based life cycle assessment (LCA) with an inventory database of the underground WWTP for a case study. Then, we identify significant factors affecting GHG emissions during service life using sensitivity analysis and suggest the proper tactics that could properly reduce GHG emissions from the WWTP.

• 한국CDE학회논문집
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• 제12권3호
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• pp.191-199
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• 2007

In order to construct a data warehouse of process plant equipment, a classification structure should be defined first, identifying not only the equipment categories but also attributes of an each equipment to represent the specifications of equipment. ISO 15926 Process Plants is an international standard dealing with the life-cycle data of process plant facilities. From the viewpoints of defining classification structure, Part 2 data model and Reference Data Library (RDL) of ISO 15926 are seen to respectively provide standard syntactic structure and semantic vocabulary, facilitating the exchange and sharing of plant equipment's life-cycle data. Therefore, the equipment data warehouse with an ISO 15926-based classification structure has the advantage of easy integration among different engineering systems. This paper introduces ISO 15926 and then discusses how to define a classification structure with ISO 15926 Part 2 data model and RDL. Finally, we describe the development result of an ISO 15926-based classification structure for a variety of equipment consisting in the reactor coolant system (RCS) of APR 1400 nuclear plant.

• The Plant Pathology Journal
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• 제30권2호
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• pp.136-150
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• 2014

Although multiple transcription factors (TFs) have been characterized via mutagenesis to understand their roles in controlling pathogenicity and infection-related development in Magnaporthe oryzae, the causal agent of rice blast, if and how forkhead-box (FOX) TFs contribute to these processes remain to be characterized. Four putative FOX TF genes were identified in the genome of M. oryzae, and phylogenetic analysis suggested that two of them (MoFKH1 and MoHCM1) correspond to Ascomycota-specific members of the FOX TF family while the others (MoFOX1 and MoFOX2) are Pezizomycotina-specific members. Deletion of MoFKH1 (${\Delta}Mofkh1$) resulted in reduced mycelial growth and conidial germination, abnormal septation and stress response, and reduced virulence. Similarly, ${\Delta}Mohcm1$ exhibited reduced mycelial growth and conidial germination. Conidia of ${\Delta}Mofkh1$ and ${\Delta}Mohcm1$ were more sensitive to one or both of the cell cycle inhibitors hydroxyurea and benomyl, suggesting their role in cell cycle control. On the other hand, loss of MoFOX1 (${\Delta}Mofox1$) did not show any noticeable changes in development, pathogenicity, and stress response. Deletion of MoFOX2 was not successful even after repeated attempts. Taken together, these results suggested that MoFKH1 and MoHCM1 are important in fungal development and that MoFKH1 is further implicated in pathogenicity and stress response in M. oryzae.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2004년도 추계학술발표회 발표논문집
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• pp.1461-1462
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• 2004

• Nuclear Engineering and Technology
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• 제49권3호
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• pp.621-631
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• 2017

Many developing countries considering the introduction of nuclear power find that large-scale reactor plants in the range of 1,000 MWe to 1,600 MWe are not grid appropriate for their current circumstance. By contrast, small modular reactors are generally too small to make significant contributions toward rapidly growing electricity demand and to date have not been demonstrated. This paper proposes a radically simplified re-design for the nuclear steam cycle for a medium-sized reactor plant in the range of 600 MWe. Historically, balance of plant designs for units of this size have emphasized reliability and efficiency. It will be demonstrated here that advances over the past 50 years in component design, materials, and fabrication techniques allow both of these goals to be met with a less complex design. A disciplined approach to reduce component count will result in substantial benefits in the life cycle cost of the units. Specifically, fabrication, transportation, construction, operations, and maintenance costs and expenses can all see significant reductions. In addition, the design described here can also be expected to significantly reduce both construction duration and operational requirements for maintenance and inspections.

• 시스템엔지니어링학술지
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• 제14권1호
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• pp.13-18
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• 2018

Plant Engineering is a series of activities going through following life cycle phases: planning, basic design, detailed design, procurement and construction, commissioning, operation and maintenance, to produce a target product. From among these phases of plant engineering life cycle, a detailed design phase is an important phase producing final design deliveries. Luckily, through technical co-operation and experiences of constructing plants, large Korean engineering companies have accumulated know-hows of efficient detailed designs. However, smaller engineering companies have less experience of performing detailed designs so there is always a risk of causing design errors in the detailed design phase. To mitigate the risk of design errors in the detailed design phase, it is necessary to systematize a concrete activity model of a detailed design phase. In this paper, we have developed a prototype of a detailed design activity model through a widely used function modeling methodology called IDEF0.

• 한국응용곤충학회지
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• 제54권3호
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• pp.247-255
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• 2015

목화진딧물(Aphis gossypii Glover) (Hemiptera: Aphididae)은 감귤에서 그을음병을 유발하여 감귤 과실에 경제적으로 피해를 주는 해충이다. 본 연구는 무가온 하우스 감귤에서 계절초기 목화진딧물이 어떠한 경로를 거쳐서 감귤나무에 정착하는지 구명하기 위하여 수행하였다. 감귤나무에서 진딧물 월동알 조사결과 가을순이 난 여름순에서 많이 발견되었는데 월동알은 대부분 조팝나무진딧물이었으며, 목화진딧물 월동알은 발견되지 않았다. 봄순에 정착하는 목화진딧물 유시형 성충은 크게 4월 하순(조기비산)과 5월 하순(지연비산)에 두 차례 관측되었다. 지연비산은 완전생활형 간모세대에서 유시형이 출현하는 시기와 일치하였다. 조기비산 시기에 황색수반트랩에서도 목화진딧물 유시형 성충이 유살되었는데 확실하지는 않으나 월동잡초에서 잔존하고 있던 불완전세대 개체군으로 추정되었다. 결과적으로 무가온 하우스 감귤에서 목화진딧물의 정착은 불완전생활형의 조기비산과 완전생활형의 지연비산으로 일어난다는 것이 확인되었다.

• 한국건축시공학회지
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• 제9권6호
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• pp.151-159
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• 2009

최근 LNG 수요 증가로 인한 해외 LNG 플랜트 프로젝트의 지속적인 발주 증가로 국내 건설업체의 해외 진출이 크게 증가하고 있다. 또한 시공 및 사업관리 기술의 발전으로 예전에 비해 고부가가치를 창출할 수 있는 기회가 많아지고 있다. 그러나 일부 선도기업을 제외한 대부분의 중견 건설업체는 고급 인력과 실무 경험의 부족으로 인한 어려움을 겪고 있는 실정이다. 선진기업의 경우 체계화된 업무 프로세스 구축을 통해 이러한 어려움을 해결하였다. 이에 본 연구에서는 플랜트 사업의 생애주기 업무 프로세스 중 시공 전 단계를 대상으로 업무를 규명하고 지식관리 항목을 포함한 상세 프로세스를 분석하였다. 이는 전체 생애주기 업무 프로세스를 분석하고 표준화하는 연구의 사전 단계로 향후 지식관리 시스템을 개발하여 통합관리를 하는데 활용 할 수 있을 것으로 기대한다.

• 한국초등과학교육학회지:초등과학교육
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• 제41권2호
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• pp.432-442
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• 2022

본 연구는 초등과학 '식물의 한살이' 단원 온라인수업에 적용할 메이커교육프로그램을 개발하고 그 효과로 과학에 대한 흥미도와 창의적 문제해결력에 미치는 영향을 알아보는 것이다. 개발된 메이커교육프로그램의 주제는 '식물의 한살이를 주제로 동화 오디오북 만들기'이다. 프로그램은 TMI 메이커교육 모형 단계에 따라 학습한 개념을 활용하여 창의적 오디오북을 제작하는 활동으로 구성하였다. 연구결과, 초등과학 '식물의 한살이' 단원 온라인수업에 메이커교육프로그램은 초등학생의 과학에 대한 흥미도와 창의적 문제해결력에 긍정적인 영향을 미쳤다. 따라서 초등과학 온라인수업에 메이커교육의 적용은 학생들의 과학에 대한 흥미도와 창의적 문제해결력 향상에 효과적이다. 그리고 초등과학 온라인 수업에 메이커교육을 활발하게 적용할 수 있는 추가적인 연구가 필요하다.