• 제목/요약/키워드: Preliminary analysis

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Identification and Analysis of External Event Combinations for Hanhikivi 1 PRA

  • Helander, Juho
    • Nuclear Engineering and Technology
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    • 제49권2호
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    • pp.380-386
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    • 2017
  • Fennovoima's nuclear power plant, Hanhikivi 1, $Pyh{\ddot{a}}joki$, Finland, is currently in design phase, and its construction is scheduled to begin in 2018 and electricity production in 2024. The objective of this paper is to produce a preliminary list of safety-significant external event combinations including preliminary probability estimates, to be used in the probabilistic risk assessment of Hanhikivi 1 plant. Starting from the list of relevant single events, the relevant event combinations are identified based on seasonal variation, preconditions related to different events, and dependencies (fundamental and cascade type) between events. Using this method yields 30 relevant event combinations of two events for the Hanhikivi site. The preliminary probability of each combination is evaluated, and event combinations with extremely low probability are excluded from further analysis. Event combinations of three or more events are identified by adding possible events to the remaining combinations of two events. Finally, 10 relevant combinations of two events and three relevant combinations of three events remain. The results shall be considered preliminary and will be updated after evaluating more detailed effects of different events on plant safety.

A Study on the Humanities-based Preliminary University Model : Focused on the P University (인문학 기반 예비대학 모델 연구: P 대학 사례를 중심으로)

  • Baik, Sangmi;Jeong, Seonho
    • Journal of the Korea Convergence Society
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    • 제13권1호
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    • pp.357-364
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    • 2022
  • This study aims to design a humanities model for preliminary universities using an online platform to develop and expand humanities thinking of preliminary university students. P University Expert Focus Group Interview and student surveys are conducted, and based on the analysis results, a preliminary university model suitable for the humanities field is proposed. Expert FGI suggested the necessity of human resources education to build an online platform-based preliminary university model and improve humanities capabilities. As a result of the student survey, it was found that a majority of the respondents had high interest in humanities and recognized the need for a humanities preliminary university. This study proposes a humanities-based preliminary university model that enables interactive communication in virtual space using the cross-platform Photo Server. The implication of this study is that it contributes to strengthening the humanities capabilities of preliminary university students by presenting an online platform preliminary university model that can respond to changes in the external environment. Since this study has a limitation in that it does not present examples of preliminary universities, it is necessary to verify the educational effect of platform-based ppreliminary university management in the future.

Analysis and Design of 750kW Nacelle Cover (750kW 나셀커버 구조해석 및 설계)

  • Park, Jae-Hyun;Bang, Jo-Hyug;Park, Jin-Il;Ryu, Ji-Yune
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2008년도 추계학술대회 논문집
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    • pp.295-298
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    • 2008
  • The major function of the nacelle cover is protecting the inside equipments. Therefore, it is required not only sufficient strength and stability but also light weight. In this paper, design loads are calculated according to the GL Wind guideline Ed. 2003. To ensure the structural safety, a composite structure is selected. The structural design is processed by two steps which are preliminary design and detail design. In the preliminary design step, a structural analysis is performed with initial thickness, 5mm. As reviewing above analysis results, weak regions of the nacelle cover reinforced using the spar cap structure which is same as the blade structure. In the analysis model, the support structure is connected with the nacelle cover and analyzed its structural safety at the same time.

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Trick or Treat? Equity Concerns in the Preliminary Feasibility Study of the Republic of Korea

  • LEE, JONGYEARN
    • KDI Journal of Economic Policy
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    • 제42권4호
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    • pp.91-116
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    • 2020
  • As a project appraisal tool, the preliminary feasibility study (PFS) has contributed to enhancing the efficiency of public investment decision-making in the Republic of Korea over the last two decades. To overcome the limitations of the efficiency-oriented cost-benefit analysis, the PFS accommodates equity concerns among regions, namely balanced regional development (BRD) analysis. This study attempts to gauge the contributions of BRD analysis to PFS results. Specifically, it addresses how effectively policy efforts to promote decision-making have been implemented in the PFS stage while also considering the balance between equity and efficiency in terms of the trade-off between them, the degree to which they influence the results, and whether the consideration of equity is in fact actually reflected in seriously underdeveloped regions as intended. The study finds that the PFS results over the last two decades have been largely in line with the background and policy objectives. Based on the findings of the study, needs for institutional improvement are suggested, including enhancements in the analysis of regional economic ripple effects and taking into account the psychological factors pertaining to the evaluators in the overall judgment.

Preliminary Economic Analysis based on Optimization of Green Ammonia Plant Configuration in the Middle East for Import into Korea

  • Hyun-Chang Shin;Hak-Soo Mok;Woo-Hyun Son
    • Journal of the Korean Society of Industry Convergence
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    • 제27권2_1호
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    • pp.277-285
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    • 2024
  • Hydrogen is considered a key energy source to achieve carbon neutrality through the global goal of 'net zero'. Due to limitations in producing green hydrogen domestically, Korean companies are interested in importing green hydrogen produced overseas. The Middle East has high-quality solar energy resources and is attracting attention as a region producing green hydrogen using renewable energy. To build a green ammonia plant, optimization of the production facility configuration and economic feasibility analysis are required. It is expected that it will contribute to reviewing the economic feasibility of constructing overseas hydrogen production plants through preliminary economic feasibility analysis.

Development of an Advanced Rotorcraft Preliminary Design Framework

  • Lim, Jae-Hoon;Shin, Sang-Joon;Kim, June-Mo
    • International Journal of Aeronautical and Space Sciences
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    • 제10권2호
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    • pp.134-139
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    • 2009
  • Various modules are generally combined with one another in order to perform rotorcraft preliminary design and its optimization. At the stage of the preliminary design, analysis fidelity is less important than the rapid assessment of a design is. Most of the previous researchers attempted to implement sophisticated applications in order to increase the fidelity of analysis, but the present paper focuses on a rapid assessment while keeping the similar level of fidelity. Each small-sized module will be controlled by an externally-operated global optimization module. Results from each module are automatically handled from one discipline to another which reduces the amount of computational effort and time greatly when compared with manual execution. Automatically handled process decreases computational cycle and time by factor of approximately two. Previous researchers and the rotorcraft industries developed their own integrated analysis for rotorcraft design task, such as HESCOMP, VASCOMP, and RWSIZE. When a specific mission profile is given to these programs, those will estimate the aircraft size, performance, rotor performance, component weight, and other aspects. Such results can become good sources for the supplemental analysis in terms of stability, handling qualities, and cost. If the results do not satisfy the stability criteria or other constraints, additional sizing processes may be used to re-evaluate rotorcraft size based on the result from stability analysis. Trade-off study can be conducted by connecting disciplines, and it is an important advantage in a preliminary design study. In this paper among the existing rotorcraft design programs, an adequate program is selected for a baseline of the design framework, and modularization strategy will be applied and further improvements for each module be pursued.

Digital Investigation First Responder and Preliminary Analyst Requirements (디지털 수사 초동조치 대응인력 및 예비분석관들이 갖추어야 할 요건)

  • James, Joshua Issac;Jang, Yunsik
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • 제16권5호
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    • pp.49-54
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    • 2016
  • As investigations dealing with digital evidence increase, so to does the need for skilled first responders and improved investigation process models. Recently the concept of digital forensic triage and preliminary analysis has been gaining popularity in investigation laboratories. At the same time, however, there has been little focus on specific training needs of first response and preliminary analysts. Instead, many organizations consider these responders to need the same skills as full digital forensic analysts. In this work we describe the 'ideal' digital investigation first responder and preliminary analyst, hardware and software requirements and most importantly, required training.

A study on the influence of the preparative education on the Elderly's attitude for death (노인의 죽음 준비교육이 죽음의 불안도에 미치는 요인분석 연구)

  • 고승덕;김은주;김영규
    • Korean Journal of Health Education and Promotion
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    • 제16권2호
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    • pp.81-92
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    • 1999
  • This study attempt to analyze the influence of the preliminary education on the Elderly's attitude for death and to present basic data for the death-preliminary education. The data were collected by administerial the Questionnaire interview with 169 the elderly who was 200 the elderly over 60 year old in silver colleges. The Questions was consists the awareness recognition of death, character, attitudes toward for death. The statistical methods used for the analysis were t-test, factor analysis. The results were the follows. There was no statistically significant relations between the fear of death and the general characteristics the elderly, but the old women felt more anxiety than old men. Especially, more aged, unhealthy the elderly felt it more and the lower educated or the single felt it more severely. The change in the attitude for death: They attitude for death was considerably changed after the preliminary education. Fears and anxiety about death were more reduced and the inevitability of death was accepted positively. This result showed the influence of the preliminary death education had positive affliction of the elderly's attitude for death. Accordingly, with the practice of the preliminary education we can release the elderly from the fear for death and guide them to live meaningly.

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Preliminary Design Analysis of an Axial-Flow Turbine (축류터어빈의 기초설계 해석)

  • Gu, Sam-Ok;Choe, Dong-Hwan
    • 한국기계연구소 소보
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    • 통권14호
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    • pp.111-119
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    • 1985
  • A review on the design analysis of an axial-flow turbine is presented. Followed by a brief introduction to the fundamentals on an axial-flow turbine, a design procedure is described with a sample design of one for a small turbo-jet engine. Design procedure is composed of two parts: one-dimensional analysis of three-dimensional effects based on radial equilibrium theory. The method described herein is so simple and rapid that it can be applied to the preliminary design analysis of turbo-machinery equipped with axial-flow turbines.

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The Optimum Design Conditions of Stirling Engines Using The Ideal Adiabatic Model (이상적인 단열모델에 의한 스터링기관의 최적설계조건)

  • 유호선
    • Transactions of the Korean Society of Mechanical Engineers
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    • 제14권3호
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    • pp.656-663
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    • 1990
  • To investigate the optimum design conditions of Stirling Engines at the preliminary design stage, comparative study between adoabatoc analysis based on an approximate analytical solution to the Ideal Adiabatic Model and the existing isothermal analysis has been carried out. The optimum phase angle obtained from adiabatic analysis to achieve the maximum work with given combination of design parameters is greater than that from isothermal analysis, while the optimum swept volume ratio is smaller. Effect of variation in the temperature ratio on the work parameter is proved to be stronger in adiabatic analysis. On the contrary, the work parameter by adiabatic analysis is less sensitive to a change in the dead volume ratio. Especially in adiabatic analysis there exists the optimum dead volume ratio maximizing the work parameter, which may provide a lower limit of it. Considering that the adiabatic model is more reasonable, signifiant differences between two methods lead to the conclusion that adiabatic analysis is preferable to isothermal one for the preliminary design of Stirling Engines.