• 제목/요약/키워드: Assessment Criterion

검색결과 442건 처리시간 0.024초

조명용센서모듈의 신뢰성평가기준 (Reliability Assessment Criteria of Sensor Module for Lighting Fixtures)

  • 정희석;박창규;정해성;백재욱
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제10권1호
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    • pp.11-24
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    • 2010
  • Lighting industry is rapidly being developed as the ubiquitous society based on sensor network emerges. This kind of paradigm shift brings the society convergence of technologies which leads to smart lighting system as well as the integration of interior and sensibility control. However, standards for sensors have not been firmly established, and problems related to quality and malfunction have been brought up, thereby calling for careful approach to the enhancement and assessment of reliability of the item. In this article reliability assessment criteria for sensor module for lighting fixtures is established in terms of performance assessment criterion and reliability assessment criterion.

새로운 파라메타인 부분방전 변화지수에 의한 발전기 고정자 권선의 절연상태 평가 (The Assessment on the Insulation Condition of Generator Stator Windings by a Novel Parameter PDI(Partial Discharge Index))

  • 황돈하;박도영;김용주;김진봉;주영호
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제48권11호
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    • pp.735-741
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    • 1999
  • The monitoring and assessment on the insulation condition of generator stator windings have been an important task of utility companies. The interest for the assessment of insulation condition has been increasing due to the need to keep old generating equipment reliable in order to extend the equipment life and to increase the generating capacity. Even though many developments and research activities for the condition assessment of generator insulation have been performed for decades, the assessment criterion in order to consistently predict the actual insulation condition is still in question. In this paper, the correlation between the parameters and the insulation condition is analyzed through the various non-destructive diagnostic tests in order to establish the assessment criterion on insulation deterioration of generator stator windings. By analyzing the correlation, PDI(Partial Discharge Index) as a novel parameter for the assessment criterion on insulation diagnosis of stator winding is proposed and verified.

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과학 수행 평가 문항의 선정 및 제작을 위한 평가 준거의 개발 (Developing of a Criterion for Selecting and Producing of Performance)

  • 김은진;박현주;강호감;노석구
    • 한국과학교육학회지
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    • 제23권1호
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    • pp.75-85
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    • 2003
  • 본 연구에서는 과학교육에서 수행평가의 올바를 사용과 정착을 위하여 과학 수행평가문항의 선정과 제작을 위한 평가준거를 개발하였다. 이를 위하여 과학과 평가목표 및 수행평가에 대한 이론적 논의를 통해 평가준거의 대범주로 평가 목표의 충실도(Fidelity), 수행평가의 특징과 구성 요소에 대한 만족도(Satisfaction), 문학의 내용 타당도 (Content Validity), 학습자에 대한 내용의 적합도 및 공정성(Suitability & Fairness), 문항의 신뢰도와 객관도(Reliability & Objectivity), 사용상의 편의성 및 실용성(Usability)의 6가지 범주를 개발하였고, 각 대범주별 하위항목을 선정하여, 총 25개의 하위 항목을 가진 평가준거표를 개발하였다. 그리고 개발된 평가준거표의 타당도는 과학교육 연구자 5명의 안면타당도로 보았고, 신뢰도 3가지 종류의 과학 수행평가문항을 과학교육 전문가 2명가 초등예비교사 6명이 평가하고, 그 결과를 Kendall계수를 통한 평가자간 합치도로 검증하였다. 그 결과 합치도는 통계적으로 유의한 수준으로 나타났다. 이상의 과정을 통하여 최종적인 평가준거표를 완성하여 제시하였다.

Decision-making of alternative pylon shapes of a benchmark cable-stayed bridge using seismic risk assessment

  • Akhoondzade-Noghabi, Vahid;Bargi, Khosrow
    • Earthquakes and Structures
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    • 제11권4호
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    • pp.583-607
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    • 2016
  • One of the main applications of seismic risk assessment is that an specific design could be selected for a bridge from different alternatives by considering damage losses alongside primary construction costs. Therefore, in this paper, the focus is on selecting the shape of pylon, which is a changeable component in the design of a cable-stayed bridge, as a double criterion decision-making problem. Different shapes of pylons include H, A, Y, and diamond shape, and the two criterion are construction costs and probable earthquake losses. In this research, decision-making is performed by using developed seismic risk assessment process as a powerful method. Considering the existing uncertainties in seismic risk assessment process, the combined incremental dynamic analysis (IDA) and uniform design (UD) based fragility assessment method is proposed, in which the UD method is utilized to provide the logical capacity models of the structure, and the IDA method is employed to give the probabilistic seismic demand model of structure. Using the aforementioned models and by defining damage states, the fragility curves of the bridge system are obtained for the different pylon shapes usage. Finally, by combining the fragility curves with damage losses and implementing the proposed cost-loss-benefit (CLB) method, the seismic risk assessment process is developed with financial-comparative approach. Thus, the optimal shape of the pylon can be determined using double criterion decision-making. The final results of decision-making study indicate that the optimal pylon shapes for the studied span of cable-stayed bridge are, respectively, H shape, diamond shape, Y shape, and A shape.

쉴드 TBM 터널의 구조물 성능 평가 기준 개발 (Development of performance assessment criterion for structures of shield TBM tunnel)

  • 성주현;이유석;홍은수;변요셉
    • 한국터널지하공간학회 논문집
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    • 제17권5호
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    • pp.553-561
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    • 2015
  • 본 연구에서는 국내에 활발히 적용되기 시작한 쉴드 TBM 터널의 합리적인 유지관리를 위한 성능평가 기준을 제시하였다. 이를 위해 국내 외 성능평가 기준을 분석하였고, 국내 시공된 쉴드 TBM 터널에 대한 현장조사 및 정밀안전진단 보고서 분석을 통한 변상사례를 조사하여 성능평가 항목을 균열, 누수, 파손, 박리, 층분리 및 박락, 백태, 품질상태, 철근노출, 탄산화, 단차, 볼트상태, 배수상태, 지반상태, 접속부상태, 공동구 상태로 선정하였다. 또한 다중의사결정기법인 AHP 기법을 활용하여 선정된 성능평가에 대한 합리적인 가중치를 산정하였다.

소규모 바다목장의 해양 환경 분석 및 평가 - 군산주변해역 (Analysis and Assessment of Environmental Factors in the Small Scale Marine Ranch around the Gunsan Coastal Areas)

  • 김종화
    • 수산해양교육연구
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    • 제20권3호
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    • pp.487-499
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    • 2008
  • This study was analyzed and assessed the environmental factors on small marine ranching sites around Gunsan Coast, West Sea of Korea. Standards of assessment are followed in the reports on the choice of marine ranching sites and regulation factors of proper site on marine artificial reefs of MOMAF. Max. current speed around Gunsan were ranged between 25.52 ~ 57.49cm/sec. These values were satisfied by comparing assessment factor such as current speed.. Factors of temperature, salinity, transparency and pH were evaluated as the proper extent. DO was not distributed as the proper extent due to different criterion. between the same assessment factor. COD, SS and nutrients were partly suited to the criteria. Especially, SS was almost higher than that of criterion. So, we are proposed to be reflected in environment characteristics of West Coast such as SS. Moreover, the extent of pollution load factors have to be specified clearly in the regulations of assessment criteria.

가정과 수행평가의 타당성과 신뢰성 연구 - 경남 농촌지역의 소인수 학급을 대상으로 - (A Study on the Validity and Reliability of Performance Assessment in Home Economics)

  • 윤성희;유태명
    • 대한가정학회지
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    • 제39권10호
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    • pp.169-186
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    • 2001
  • The purpose of the study was to verify validity and reliability of performance assessment in home economics by applying performance assessment tools developed by Korean Curriculum Assessment Institute and by the researcher to a class of 17 high school female students in a rural area. For the purpose of this study, the research question was formulated and addressed:“How are the validity and reliability of performance assessment in home economics\ulcorner” The results of the study were as follows. 1. The results of testing validity a. Thirteen high school home economics teachers, whose average teaching years is ten years verified high validity in the contents of performance assessment. b. In the validity of the items that is verified being based on the scores of high school entrance examination of 2000 school year, the essay type showed its characteristics as performance assessment. c. The generalizability among assessment methods was not high. 2. The results of testing reliability Both Cronbach's $\alpha$, inter-item reliability of the assessment tools used in the research, and reliability among the raters were high. But reliability among the tasks was relatively low. This study proposed that the diverse performance methods, the increasing number of assessment, the explicit assessment criterion, and scoring criterion are needed to satisfying validity and reliability of performance assessment.

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국내 IUCN Red List of Ecosystem(생태계 적색목록) 평가를 위한 국제 사례 연구와 전략 제시 (International Case Study and Strategy Proposal for IUCN Red List of Ecosystem(RLE) Assessment in South Korea)

  • 한상학;강성룡
    • 한국습지학회지
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    • 제25권4호
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    • pp.408-416
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    • 2023
  • IUCN 생태계 적색목록은 생물다양성의 감소 위험이 높은 생태계를 평가하고 식별하기 위한 글로벌 표준으로, 효과적인 생태계 관리 및 보전 정책 수립에 필요한 과학적 근거를 제공한다. IUCN 생태계 적색목록은 쿤밍-몬트리올 글로벌 생물다양성 프레임워크 목표 A의 핵심지표(A.1)로 지정하였다. 생태계 적색목록 평가는 특정 생태계 유형을 분포의 감소(기준 A), 제한된 분포(기준 B), 환경 황폐화(기준 C), 생물학적 상호작용의 변화(기준 D), 생태계 붕괴 위험의 정량적 추정(기준 E)으로 생태계 붕괴 징후를 판별한다. IUCN 생태계 적색목록은 2014년부터 110개 이상의 국가에서 평가를 진행하였다. 80% 이상이 육상 및 육상-담수 생태계에서 평가를 진행하였으며, 이중 열대림과 아열대림에 위협 받는 생태계가 집중 분포하고 있다. 평가 기준은 공간적 징후(기준 A 및 B)에서 68.8%로 집중되어 있다. 국내에서 생태계 적색목록을 평가를 적용하기 위한 고려사항은 크게 세가지로 나뉜다. 첫째, 국내 적용가 능한 지구 생태계 유형(GET)을 적립해야 한다. 둘째, 생태계 적색목록 범주·기준 중 공간적 징후 평가에서 국내의 소규모로 이루어진 다양한 생태계 유형에 적용 가능한지를 판단해야 한다. 마지막으로 평가를 위한 활용 가능한 시계열(50년) 데이터 수집을 고려해야 한다. 이러한 고려사항을 바탕으로 국내에 IUCN 생태계 적색목록 평가를 적용하면, 우리나라의 독특한 생태계 유형의 현재 상태를 정확하게 파악할 수 있을 것이며, 이는 세계적인 생태계 보전 및 복원 노력에 기여할 것이다.

Pressure impulse diagrams for simply-supported steel columns based on residual load-carrying capacities

  • Park, Jong Yil;Krauthammer, Theodor
    • Structural Engineering and Mechanics
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    • 제39권2호
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    • pp.287-301
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    • 2011
  • This paper is focused on the residual capacity of steel columns, as a damage criterion. Load-Impulse (P-I) diagrams are frequently used for analysis, design, or assessment of blast resistant structures. The residual load carrying capacity of a simply supported steel column was derived as a damage criterion based on a SDOF computational approach. Dimensionless P-I diagrams were generated numerically with this quantitative damage criterion. These numerical P-I diagrams were used to show that traditional constant ductility ratios adopted as damage criteria are not appropriate for either the design or damage assessment of blast resistant steel columns, and that the current approach could be a much more appropriate alternative.

삼축응력 기반의 파괴변형률 기준을 적용한 가우지 손상배관의 건전성 평가 (Structural Integrity Assessments of Pressurized Pipes with Gouge using Stress-Modified Fracture Strain Criterion)

  • 오창균;김윤재;박진무;백종현;김영표;김우식
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 추계학술대회 논문집
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    • pp.808-813
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    • 2005
  • Structural integrity assessment of defected pipe is important in fitness for service evaluation and proper engineering assessment is needed to determine whether pipelines are still fit for service. This paper present a failure prediction of gas pipes made of APIl X65 steel with gouge using stress-modified true fracture strain, which is regarded as a criterion of ductile fracture. For this purpose, API X65 pipes with gouge are simulated using elastic-plastic FE analyses with the proposed ductile failure criterion and the resulting burst pressures are compared with experimental data. Agreements are quite good, which gives confidence in the use of the proposed criteria to defect assessment fer gas pipelines. Then, further extensive finite element analyses are performed to obtain the burst pressure solution of pipes with gouge as a function of defect depth, length and pipeline geometry.

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