• Title/Summary/Keyword: Assessment Criterion

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

  • Jeong, Hee-Suk;Park, Chang-Kyu;Jeong, Hai-Sung;Baik, Jai-Wook
    • Journal of Applied Reliability
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    • v.10 no.1
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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.

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

  • Hwang, Don-Ha;Park, Do-Yeong;Kim, Yong-Ju;Kim, Jin-Bong;Ju, Yeong-Ho
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.11
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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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Developing of a Criterion for Selecting and Producing of Performance (과학 수행 평가 문항의 선정 및 제작을 위한 평가 준거의 개발)

  • Kim, Eun-Jin;Park, Hyun-Ju;Kang, Ho-Kam;Noh, Suk-Gu
    • Journal of The Korean Association For Science Education
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    • v.23 no.1
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    • pp.75-85
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    • 2003
  • We have developed of a criterion that would help to select and develop performance assessments in science education. There are six categories of a criterion: Fidelity, satisfaction, content validity, fairness & suitability, reliability & objectivity, and usability. There are the total of 25 sub-categories under the six categories. Five science educators evaluated the validity of the criterion. For reliability of the criterion, Kendall's tau-b was used. Eight science educators and elementary teachers evaluated three performance assessment tasks for the correspondence of the criterion. This study also discuss the implications of this criterion as well.

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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    • v.11 no.4
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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.

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

  • Seong, Joo-Hyun;Lee, Yu-Seok;Hong, Eun-Soo;Byun, Yo-Seph
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.17 no.5
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    • pp.553-561
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    • 2015
  • In this study, the performance assessment criterion for reasonable maintenance of shield TBM tunnel was presented. The performance assessment items such as crack, leakage, breakage, spalling, exfoliation/detachment, efflorescence, quality condition, exposure of steel, carbonation, faulting step, bolts condition, drainage condition, ground condition, contact section condition and conduit condition were selected by analyzing domestic and foreign performance assessment criterions and investigating segment lining deterioration cases through the site investigation and in-depth inspection analysis result on the shield TBM tunnel. In addition, the reasonable weight using AHP (Analytic Hierarchy Process) were estimated.

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

  • Kim, Jong-Hwa
    • Journal of Fisheries and Marine Sciences Education
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    • v.20 no.3
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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.

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

  • 윤성희;유태명
    • Journal of the Korean Home Economics Association
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    • v.39 no.10
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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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International Case Study and Strategy Proposal for IUCN Red List of Ecosystem(RLE) Assessment in South Korea (국내 IUCN Red List of Ecosystem(생태계 적색목록) 평가를 위한 국제 사례 연구와 전략 제시)

  • Sang-Hak Han;Sung-Ryong Kang
    • Journal of Wetlands Research
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    • v.25 no.4
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    • pp.408-416
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    • 2023
  • The IUCN Red List of Ecosystems serves as a global standard for assessing and identifying ecosystems at high risk of biodiversity loss, providing scientific evidence necessary for effective ecosystem management and conservation policy formulation. The IUCN Red List of Ecosystems has been designated as a key indicator (A.1) for Goal A of the Kunming-Montreal Global Biodiversity Framework. The assessment of the Red List of Ecosystems discerns signs of ecosystem collapse through specific criteria: reduction in distribution (Criterion A), restricted distribution (Criterion B), environmental degradation (Criterion C), changes in biological interaction (Criterion D), and quantitative estimation of the risk of ecosystem collapse (Criterion E). Since 2014, the IUCN Red List of Ecosystems has been evaluated in over 110 countries, with more than 80% of the assessments conducted in terrestrial and inland water ecosystems, among which tropical and subtropical forests are distributed ecosystems under threat. The assessment criteria are concentrated on spatial signs (Criteria A and B), accounting for 68.8%. There are three main considerations for applying the Red List of Ecosystems assessment domestically: First, it is necessary to compile applicable terrestrial ecosystem types within the country. Second, it must be determined whether the spatial sign assessment among the Red List of Ecosystems categories can be applied to the various small-scale ecosystems found domestically. Lastly, the collection of usable time series data (50 years) for assessment must be considered. Based on these considerations, applying the IUCN Red List of Ecosystems assessment domestically would enable an accurate understanding of the current state of the country's unique ecosystem types, contributing to global efforts in ecosystem conservation and restoration.

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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    • v.39 no.2
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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.

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

  • Oh C.K.;Kim Y.J.;Park J.M.;Baek J.H.;Kim Y.P.;Kim W.S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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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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