• 제목/요약/키워드: trend analyses

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FLUENT 5.4 코드를 이용한 양방향 유동 튜브에 대한 유동해석 (Flow Analyses using FLUENT 5.4 Code for the Bi-directional Flow Tube)

  • 강경호;윤병조;백원필
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 추계학술대회
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    • pp.934-938
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    • 2003
  • Flow analyses using FLUENT 5.4 code were performed to validate the application of the local bidirectional flow tube in case of water and air flow. In this study, sensitivity studies have been performed to optimize the design features of the bi-directional flow tube which can be applied for the various experimental conditions. 2-dimensional axisymmetric steady state flow analyses have been performed. By calculating the differential pressure at both the front and the rear hole of the flow tube, K values were evaluated. The K values show good linearity regardless of the tube sizes and the Re numbers in both water and air flow. And system pressure and water subcooling didn’'t affect the K values. Under the elevated pressure of 80bar with 80K water subcooling, the K value indicates a similar trend with the case of 2bar with 80K water subcooling.

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VARIABILITY OF THE LATENT HEAT FLUX DURING 1988-2005

  • Iwasaki, Shinsuke;Kubota, Masahisa
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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    • pp.289-292
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    • 2008
  • Recently, several satellite data analyses projects and numerical weather prediction (NWP) reanalysis projects have produced the ocean surface Latent Heat Flux (LHF) data sets in the global coverage. Comparisons of these LHF data sets showed substantial discrepancies in the LHF values. Recently, the increase of LHF in during 1970s-1990s over the global ocean is shown by the LHF data that have been developed at the Objective Analyzed Air-Sea Fluxes (OAFlux) project. It is interesting to investigate the existence of the increase of LHF over a global ocean in the other LHF products. It is interesting to investigate the existence of the increase of LHF over a global ocean in the other LHF products. In this study, we assessed the consistencies and discrepancies of the inter-annual variability and decadal trend for the period 1988-2005 among six LHF products ((J-OFURO2, HOAPS3, IFREMER, NCEP1,2 and OAFlux) over the global ocean. As results, all LHF products showed a positive trend. In particular, the positive trend in satellite-based data analyses (J-OFURO2, HOAPS3, IFREMER) is larger than that in reanalysis products (NCEP1/2). Also, the consistencies and discrepancies are shown on the spatial patterns of the LHF trends across the six data sets. The positive trend of LHF is remarkable in the regions of western boundary currents such as the Kuroshio and the Gulf Stream in all LHF data sets. But, the discrepancies are shown on the spatial patterns of the LHF trends in tropics and subtropics. These discrepancies are primarily caused by the differences of the input meteorological state variables, particularly for the air specific humidity, used to calculate LHF.

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Technical note: Estimation of Korean industry-average initiating event frequencies for use in probabilistic safety assessment

  • Kim, Dong-San;Park, Jin Hee;Lim, Ho-Gon
    • Nuclear Engineering and Technology
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    • 제52권1호
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    • pp.211-221
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    • 2020
  • One fundamental element of probabilistic safety assessment (PSA) is the initiating event (IE) analysis. Since IE frequencies can change over time, time-trend analysis is required to obtain optimized IE frequencies. Accordingly, such time-trend analyses have been employed to estimate industry-average IE frequencies for use in the PSAs of U.S. nuclear power plants (NPPs); existing PSAs of Korean NPPs, however, neglect such analysis in the estimation of IE frequencies. This article therefore provides the method for and results of estimating Korean industry-average IE frequencies using time-trend analysis. It also examines the effects of the IE frequencies obtained from this study on risk insights by applying them to recently updated internal events Level 1 PSA models (at-power and shutdown) for an OPR-1000 plant. As a result, at-power core damage frequency decreased while shutdown core damage frequency increased, with the related contributions from each IE category changing accordingly. These results imply that the incorporation of time-trend analysis leads to different IE frequencies and resulting risk insights. The IE frequency distributions presented in this study can be used in future PSA updates for Korean NPPs, and should be further updated themselves by adding more recent data.

Effect of Importance of Selection Attributes on Satisfaction and Repurchase of Nostalgic Desserts among 20's

  • Choo Yeon KIM;Seunghyeon LEE;Seong Soo CHA
    • 산경연구논집
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    • 제15권3호
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    • pp.1-9
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    • 2024
  • Purpose: This research aimed at understanding the dynamics of consumer behavior in the context of nostalgic desserts. The primary objective is to scrutinize how different attributes like quality, health, convenience, and trend influence customer satisfaction and their subsequent decision to repurchase nostalgic desserts. Research Method: The study leverages structural equation modeling, incorporating statistical tools such as SPSS and AMOS for a thorough analysis. It involves collecting data over a specified period, followed by correlation and trend analyses to deduce patterns and relationships. Results: The findings reveal that attributes such as quality, health, convenience, and trend significantly impact customer satisfaction and repurchase intentions. Interestingly, economic factors appeared to have a negligible effect on these decisions. The study offers a comprehensive understanding of the factors that influence consumer decisions in the context of nostalgic desserts, providing valuable implications for both academic research and practical marketing strategies. Conclusions: The insights garnered from this research are pivotal for formulating marketing strategies for nostalgic dessert brands. It underscores the importance of accentuating quality, health, and trend in product offerings to boost customer satisfaction and encourage repurchases. The study also sheds light on the evolving nature of consumer preferences and the integral role of nostalgia in shaping purchasing behaviors.

특허정보를 활용한 경북지역 ICT 개발동향 분석 및 유망기술 도출에 관한 연구 (A Study on the Extracting ICT Development Trend and Promising Technologies by Utilizing Patent Information in Gyeongbuk Province)

  • 한장협;김채복
    • 기술혁신학회지
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    • 제21권1호
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    • pp.236-264
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    • 2018
  • 본 논문에서는 ICT(Information and Communications Technology) 산업 관련 기술을 주제로 경상북도의 특허출원 동향과 특허맵 중 하나인 특허 포트폴리오 분석을 적용하여 ICT 기술의 향후 방향을 살펴본 연구이다. 이에 본 연구는 경북지역 ICT 산업의 기술 동향 및 기술개발 실태를 특허정보를 통해 살펴보고, 특허 포트폴리오 분석을 통한 지역 ICT 산업의 기술방향 정도를 가늠하여, 연구개발전략 수립에 활용되는 것을 그 목적으로 한다. 경상북도에서 출원된 특허를 대상으로 국제특허분류(IPC: International Patent Classification) 별 기술동향 파악을 하였고 향후 미래유망기술 도출에 대해 분석하였다. 동향파악을 위해서는 ICT 분류코드에 의거하여 각 부문별로 출원된 특허에 대해 분석하였다. 그 결과 경상북도의 특허 출원 동향과 기술별 점유율 및 구간별 특허활동 현황, ICT 중분류 기술별 특허 출원 동향, ICT 기술시장 성장단계현황, 연구주체별 특허 출원 동향, 연구주체 간 공동연구 현황, 주요 출원인 특허 출원 동향 분석 등의 분석결과를 제시하였다. 또한 유망기술 도출을 통해 경북 ICT산업의 기술적 방향을 살펴보았다. 연구결과를 바탕으로 경북 ICT 산업의 기술 경쟁력 확보에 기여하고자 하였고, 더불어 향후 ICT 산업기술의 지향 방향과 기술정책 전략 수립에 도움이 되고자 하였다.

지상무인전투차량 자율주행 기술 동향분석 및 발전방향 (The Development Trend Analysis of Autonomous Driving Technology for Unmanned Ground Combat Vehicles)

  • 이진호;김석;이천수
    • 한국군사과학기술학회지
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    • 제14권5호
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    • pp.760-767
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    • 2011
  • To strategically select the technology priority based on the understanding of technology development trends and prospects is very important. To provide such guidance for autonomous driving technology in unmanned ground combat vehicles, this report deals with followings; 1) The core technologies for autonomous driving are reviewed. 2) And domestic and foreign policies for relevant technology development are investigated. 3) Then, to estimate the technology development trend, the published patents and research papers are analyzed. 4) Based on those analyses, domestic technology level and development prospects are expected.

프로그램 및 자연어 표절 검출을 위한 국내.외 동향 및 감정 S/W 툴의 분석 (Analysis of Domestic.Foreign Trend and Assessment Tools for Programs and Natural Language Plagiarism)

  • 조동욱;신승수;윤미희
    • 한국컴퓨터산업학회논문지
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    • 제3권12호
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    • pp.1659-1668
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    • 2002
  • 컴퓨터 소프트웨어, 디지털 콘텐츠등 디지털 정보 재산권의 보호는 현재 뿐 아니라 향후 국가의 국력을 좌우할 수 있을 정도로 대단히 주요한 과제가 아닐 수 없다. 본 논문에서는 디지털 정보 재산권과 관련된 국내ㆍ외 연구 동향과 표절의 감정을 체계적으로 행하기 위한 소프트웨어 툴에 대해 비교ㆍ분석을 행하고자 한다. 주요 내용으로는 JISC을 중심으로 한 국외 감정 기관의 사업 동향과 분석 그리고 국내기관이나 단체의 움직임을 살펴보고자 한다. 또한 자연어 표절이나 프로그램 표절을 감정 할 수 있는 S/W툴에 대해 비교ㆍ분석을 행하고자 한다.

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안전항 판례동향과 시사점에 관한 연구 (A study on the precedent trend of safe port and its Implication)

  • 김태우;이원정
    • 대한안전경영과학회지
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    • 제12권3호
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    • pp.93-99
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    • 2010
  • As more than 90% of global trade is carried by sea there is little doubt that the safety of the ports at which the world's trading fleet call is of critical concern. The concept of 'safe port' continues to be an area of critical concern for charterers and ship-owners. In light of increased global security and health risks the recognised principles are under security. This paper examines the nature of safe port, and analyses the precedent trend of safe port and its Implication

A research trend of occupational ergonomics in Korea

  • Lee, S.D.
    • 대한인간공학회지
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    • 제9권2호
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    • pp.65-72
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    • 1990
  • The historical development process and the current research trends of ergonmics in Korea are reviewed and organized in this paper. The recommended research directions in the near future are also discussed based upon the analyses of the potential major key industries of Korea in 1990's. Keynords: Human Engineering Society of Korea; Research activities in Ergonomics; Ergonomics educations

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