• Title/Summary/Keyword: Theory-based Assessment

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Assessment of Concrete Lining Using Fuzzy Theory (퍼지 이론을 이용한 터널 콘크리트 라이닝의 상태평가)

  • 이광호;배규진;이석원;이성원;조만섭
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.153-160
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    • 1999
  • It has been recognized that the assessment of concrete lining is very uncertain and subjective depending on the engineers who are in charge. T-FLAS which was based on fuzzy theory was developed in this study for the quantitative and objective assessment of the concrete lining in tunnels. Based on the application of T-FLAS on the evaluated field data, it was shown that the assessment system using fuzzy theory(T-FLAS) can be the effective and objective method for the assessment of concrete lining.

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Development of Integrity Assessment Model for Reinforced Concrete Highway Bridges Using Fuzzy Concept (Fuzzy 개념을 이용한 RC도로교의 건전성평가 모델 개발)

  • Na, Ki-Hyun;Park, Ju-Won;Lee, Cheung-Bin;Jung, Chul-Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.2 no.2
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    • pp.151-161
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    • 1998
  • In this study, an attempt is made to apply the concept of fuzzy-bayesian theory to the integrity assessment of RC highway bridge, and uncertainty states are represented in terms of fuzzy sets which define several linguistic variables such as "very good", "good", "average", "poor", "very poor", etc. Especially, the concept of fuzzy conditional probability aids to derive a new reliability analysis which includes the subjective assessment of engineers without introducing any additional correction factors. The fuzzy concept are also used as reliability indexes for the condition assessment based on the proposed models, the proposed fuzzy theory-based approach with the results of visual inspection and extensive field load tests are applied to the integrity assessment of a new RC highway bridge, namely, Jichok bridge.

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A Study on Fuzzy Logic Method for the Assessment of Tunnel Concrete Lining (터널 콘크리트 라이닝의 상태평가를 위한 퍼지추론기법 연구)

  • 이성원;조만섭;이광호;이석원;배규진;안영기
    • Tunnel and Underground Space
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    • v.9 no.4
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    • pp.337-349
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    • 1999
  • There are many difficulties to the engineers in the assessment of tunnel safety. Consequently, objective assessment of concrete lining is hard even by the experts of tunnel assessment. Of several difficulties in the assessment of tunnel safety, in this study, tunnel concrete lining was focussed iud evaluated quantitatively and objectively using the Fuzzy theory which it generally considered to be appropriate for the assessment, control and judgment. T-FLAS based on fuzzy theory was developed in this study for the quantitative and objective assessment of the concrete lining in tunnels. Based on the application of T-FLAS on the evaluated field data, it was shown that the assessment system using fuzzy theory(T-FLAS) can be the effective and objective method for the assessment of concrete lining.

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Performance-based remaining life assessment of reinforced concrete bridge girders

  • Anoop, M.B.;Rao, K. Balaji;Raghuprasad, B.K.
    • Computers and Concrete
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    • v.18 no.1
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    • pp.69-97
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    • 2016
  • Performance-based remaining life assessment of reinforced concrete bridge girders, subject to chloride-induced corrosion of reinforcement, is addressed in this paper. Towards this, a methodology that takes into consideration the human judgmental aspects in expert decision making regarding condition state assessment is proposed. The condition of the bridge girder is specified by the assignment of a condition state from a set of predefined condition states, considering both serviceability- and ultimate- limit states, and, the performance of the bridge girder is described using performability measure. A non-homogeneous Markov chain is used for modelling the stochastic evolution of condition state of the bridge girder with time. The thinking process of the expert in condition state assessment is modelled within a probabilistic framework using Brunswikian theory and probabilistic mental models. The remaining life is determined as the time over which the performance of the girder is above the required performance level. The usefulness of the methodology is illustrated through the remaining life assessment of a reinforced concrete T-beam bridge girder.

Assessment by Parents and Teachers of Young Children's Potential Abilities Based on Multiple Intelligences Theory (다중지능에 의한 부모-교사의 유아 잠재능력 평가간의 인식비교 연구)

  • Kim, Myoung Hee;Shin, Hwa Sik
    • Korean Journal of Child Studies
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    • v.22 no.4
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    • pp.33-50
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    • 2001
  • This research analyzed differences between parents and teachers in assessment of young children's potential abilities based on multiple intelligences theory. Subjects were 10 boys and 10 girls, 4 and 5 years of age and their parents and teachers. Children's potential abilities were measured by the Korean Project Spectrum(KPS) and by the assessments of parents and teachers. Data were analyzed by SPSS. Statistical methods were Cronbach's ${\alpha}$, t-test, and Pearson's and Spearman's correlations. Results revealed differences between the assessments of parents and of teachers. While teacher assessments were very similar to the results of the KPS on logical mathematical and linguistic intelligence, the results of parents' assessments were different from the results of the KPS on musical, interpersonal-intrapersonal, and naturalistic intelligence.

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Network Security Situation Assessment Method Based on Markov Game Model

  • Li, Xi;Lu, Yu;Liu, Sen;Nie, Wei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.5
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    • pp.2414-2428
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    • 2018
  • In order to solve the problem that the current network security situation assessment methods just focus on the attack behaviors, this paper proposes a kind of network security situation assessment method based on Markov Decision Process and Game theory. The method takes the Markov Game model as the core, and uses the 4 levels data fusion to realize the evaluation of the network security situation. In this process, the Nash equilibrium point of the game is used to determine the impact on the network security. Experiments show that the results of this method are basically consistent with the expert evaluation data. As the method takes full account of the interaction between the attackers and defenders, it is closer to reality, and can accurately assess network security situation.

Development and Evaluation of Criterion-Referenced Performance Assessment Items Based on the 7th National Science Curriculum -Subject Unit of Reproduction and Biological Accumulation- (제7차 교육과정에 근거한 준거지향적 수행평가 문항의 개발과 평가 -고등학교 과학 "생식"과 "생물 농축" 단원을 중심으로-)

  • Chung, Young-Lan;Park, Jin-Joo
    • Journal of The Korean Association For Science Education
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    • v.24 no.3
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    • pp.519-531
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    • 2004
  • In recent years, there has been an increased emphasis on performance assessment to evaluate students' abilities. Our nation has introduced a change in testing and assessment. Additional work on the efficacy, reliability, and comparability in order to develop the performance assessment item has been needed in the enforcement of the 7th National Science Curriculum. Also, criteria for professional and technical standards has been needed to be developed. The purpose of this study was to draw out various key concepts and to develop achievement standards, assessment standards and performance assessment items based on the 7th National Science Curriculum on the subject matter of reproduction(chapter 13) and biological accumulation(chapter 17). And also, this study examined the validity of completed performance assessment items based on classical test theory and polytomous item response theory. Twelve key concepts in chapter 13(reproduction) and four from chapter 17(biological accumulation) were abstracted. Twenty-six achievement standards in chapter 13(reproduction), and nine in chapter 17(biological accumulation) were developed. The achievement standards were determined in terms of knowledge(K), process skill(P) and attitude(A). Twenty-five assessment standards in chapter 13(reproduction) and nine in chapter 17(biological accumulation) were developed. Based on the developed achievement standards and assessment standards, twenty-two performance assessment items(seventeen open-ended questions, three essays, and two portfolios) with concrete grading criteria were developed. Eight open-ended items were applied to 240 10th graders to evaluate reliabilities of the test which consisted of four items per each chapter. The results would be suggested that the applied items were valid for performance assessment because item difficulties and item discriminations were proper. There was not much differences in item discrimination between interpretation from classical test theory and that from polytomous item response theory. However, there were some differences in item difficulties between the interpretations of two theories because the characteristics of examinees were reflected in classical test theory.

A Multi-attribute Index for Assessing Environmental Impacts of Regional Development Projects: A Case Study of Korea (다속성 효용이론을 이용한 다속성 지수의 개발 - 지역개발에 대한 의사결정을 중심으로 -)

  • Kwak, Seung-Jun;Yoo, Seung-Hoon;Shin, Chul-Oh
    • Environmental and Resource Economics Review
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    • v.10 no.3
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    • pp.345-366
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    • 2001
  • Evaluating environmental impacts of regional development projects has critical importance in environmental management aspect. This paper uses multi-attribute utility theory as a basis for obtaining a value index to assess the environmental impacts and applies the theory to a specific Korean case study. To structure and quantify basic values for the assessment, we elicited important attributes, then refined and structured them into a hierarchy. An environmental multi-attribute index is constructed as a multi-attribute utility function, based on value judgments provided by a group of technical experts, policy makers, and a decision-maker at Korean Ministry of Environment. The implications of the results are also discussed. We found that the work and results can provide valuable insights for assessment of environmental consequences.

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Mullti-factor fusion Process for Pedestrian Risk Assesment (보행자의 위험도 산출을 위한 다중요인 융합 처리)

  • Ryu, Chang-Keun
    • The Journal of the Korea institute of electronic communication sciences
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    • v.11 no.8
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    • pp.817-826
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    • 2016
  • The importance of common life safety is getting growth with modern society progress. This paper shows the extended way of assessment of danger that outcomes better result than the previous assessment based on crime frequency assessment. The assessment of this paper involves time, illusion degree, floating population and the personal condition. The evidence theory is not beneficial when the number of component increases, the assessment is more complex than before. This research solves the problem through the fuzzy theory adoption. This paper shows more advanced result that can express better danger awareness and get the adjective expression.

Creep damage and life assessment of thick cylindrical pressure vessels with variable thickness made of 304L austenitic stainless steel

  • Kashkoli, Mosayeb Davoudi;Tahan, Khosro Naderan;Nejad, Mohammad Zamani
    • Steel and Composite Structures
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    • v.32 no.6
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    • pp.701-715
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    • 2019
  • Using first-order shear deformation theory (FSDT), a semi-analytical solution is employed to analyze creep damage and remaining life assessment of 304L austenitic stainless steel thick (304L ASS) cylindrical pressure vessels with variable thickness subjected to the temperature gradient and internal non-uniform pressure. Damages are obtained in thick cylinder using Robinson's linear life fraction damage rule, and time to rupture and remaining life assessment is determined by Larson-Miller Parameter (LMP). The thermo-elastic creep response of the material is described by Norton's law. The novelty of the present work is that it seeks to investigate creep damage and life assessment of the vessels with variable thickness made of 304L ASS using LMP based on first-order shear deformation theory. A numerical solution using finite element method (FEM) is also presented and good agreement is found. It is shown that temperature gradient and non-uniform pressure have significant influences on the creep damages and remaining life of the vessel.