• 제목/요약/키워드: state evaluation

검색결과 3,102건 처리시간 0.03초

A comprehensive evaluation method study for dam safety

  • Jia, Fan;Yang, Meng;Liu, Bingrui;Wang, Jianlei;Gao, Jiaorong;Su, Huaizhi;Zhao, Erfeng
    • Structural Engineering and Mechanics
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    • 제63권5호
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    • pp.639-646
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    • 2017
  • According to the multi-index system of dam safety assessment and the standard of safety, a comprehensive evaluation model for dam safety based on a cloud model is established to determine the basic probability assignment of the Dempster-Shafer theory. The Dempster-Shafer theory is improved to solve the high conflict problems via fusion calculation. Compared with the traditional Dempster-Shafer theory, the application is more extensive and the result is more reasonable. The uncertainty model of dam safety multi-index comprehensive evaluation is applied according to the two theories above. The rationality and feasibility of the model are verified through application to the safety evaluation of a practical arch dam.

Assessment of speckle image through particle size and image sharpness

  • Qian, Boxing;Liang, Jin;Gong, Chunyuan
    • Smart Structures and Systems
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    • 제24권5호
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    • pp.659-668
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    • 2019
  • In digital image correlation, speckle image is closely related to the measurement accuracy. A practical global evaluation criterion for speckle image is presented. Firstly, based on the essential factors of the texture image, both the average particle size and image sharpness are used for the assessment of speckle image. The former is calculated by a simplified auto-covariance function and Gaussian fitting, and the latter by focusing function. Secondly, the computation of the average particle size and image sharpness is verified by numerical simulation. The influence of these two evaluation parameters on mean deviation and standard deviation is discussed. Then, a physical model from speckle projection to image acquisition is established. The two evaluation parameters can be mapped to the physical devices, which demonstrate that the proposed evaluation method is reasonable. Finally, the engineering application of the evaluation method is pointed out.

Comprehensive Evaluation of Impacts of Connecting Distributed Generation to the Distribution Network

  • Jin, Wei;Shi, Xuemei;Ge, Fei;Zhang, Wei;Wu, Hongbin;Zhong, Chengyuan
    • Journal of Electrical Engineering and Technology
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    • 제12권2호
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    • pp.621-631
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    • 2017
  • In this paper, we study the various impacts of connecting distributed generation (DG) to the distribution network. The comprehensive evaluation index system (CEIS) of four hierarchies is established, considering economy, reliability and voltage quality, and the calculation methods of different indexes are presented. This paper puts forward an improved triangular fuzzy number analytic hierarchy process (ITFNAHP) to weight the second level indexes (SLI) and the third level indexes (TLI), and calculates the variation coefficient to weight the fourth level indexes (FLI). We calculate the comprehensive weight coefficients based on the weight coefficients of the SLI, TLI and FLI, and then calculate the comprehensive evaluation of satisfaction (CES) of different access schemes. On the basis of the IEEE 33-bus example system, simulations of the calculation methods and the comprehensive evaluation method are carried out under different DG access schemes according to the same total investment cost and the same permeability, respectively, and the simulation results are analyzed and discussed.

Middle School Students' Knowledge State Analysis about Light

  • Lee, Hyong-Jae;Ha, Ji-Seon;Park, Sang-Tae
    • 한국과학교육학회지
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    • 제32권8호
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    • pp.1345-1355
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    • 2012
  • In this study, 15 evaluation questions about light were developed and presented to 30 middle school students, and then the theory of knowledge space was used to analyze the status of the middle school students' knowledge about light. Not only was the state of the students' knowledge about light intended to be measured by schematizing the knowledge hierarchy obtained; the data obtained were also intended to be used as basic materials to improve the teaching methods used. To achieve the purpose of this study, the evaluation results, the individual knowledge state, and the hierarchy of questions were analyzed. As a result, different knowledge structures were found in the individuals and groups, and it was determined that individuals and groups should be diagnosed differently. In addition, the implication that there is a connection between each question and the individual knowledge state was drawn.

Identification of Superior Polyvoltine Hybrids (polyvoltine${\times}$bivoltine) of Silkworm, Bombyx mori L.

  • Rao, C.G.P.;Chandrashekharaiah;Basha, K.Ibrahim;Seshagiri, S.V.;Ramesh, C.;Nagaraju, H.
    • International Journal of Industrial Entomology and Biomaterials
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    • 제8권1호
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    • pp.43-49
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    • 2004
  • Ten promising polyvoltine mulberry silkworm strains(SDMGl, SDMG2, SDMG3, SDMG4, SDMWl, SDMW2, RMWl, RMW2, RMW3 and RMW4) that are superior in quantitative and qualitative traits have been synthesized in the polyvoltine breeding laboratory of Andhra Pradesh State Sericulture Research & Development Institute, Hindupur through systematic hybridization and appropriate selection methods. After the genotypes were found homozygous for the desired traits, they have been crossed with 3 bivoltine testers $(APS8, APS4 and {NB_2}{D_4})$ and thirty new hybrid combinations were developed for the assessment of their hybrid performance. Phenotypic expressions of economically important quantitative and qualitative traits of fist filial generation were measured and subjected for statistical analysis. Evaluation Index and Subordinate Function methods were employed for the assessment of hybrid performance since they are widely used in silkworm hybrid evaluation. Total of seven poly${\times}$bivoltine combinations, which ranked high in both the methods, were selected as potential combinations for further field test. These combinations also ranked significantly higher than the control hybrid (APMl${\times}$APS8).

콘크리트 블록을 이용한 실교량의 구조성능평가기법 (Structural Evaluation of Prototype Bridge using Concrete Weight Blocks)

  • 심종성;오홍섭;유재명
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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    • pp.429-432
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    • 2000
  • Test methods by hydraulic oil or vehicular live load have been used for structural evaluation of prototype bridge. However it has been reported that the use of hydraulic jack has some disadvantages for the view of safety and economy, and the complete structural evaluation through each loading state can not be accomplished blocks is presented to overcome those demerits. To verify the application and safely of the use of concrete weight blocks during each loading state, it is applied to prototype deteriorated bridge. As a result, it could be evaluated the structural behavior completely using the concrete weight blocks

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태양광발전원(太陽光發電原)을 고려한 전력계통(電力系統)의 확률논적(確率論的)인 신뢰도(信賴度) 평가(評價)에 관한 연구(硏究) (A Study on Probabilistic Reliability Evaluation of Power System Considering Solar Cell Generators)

  • 박정제;오량;최재석;차준민
    • 전기학회논문지
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    • 제58권3호
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    • pp.486-495
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    • 2009
  • This paper proposes a new methodology on reliability evaluation of a power system including solar cell generators (SCG). The SCGs using renewable energy resource such as solar radiation(SR) should be modeled as multi-state operational model because the uncertainty of the resource supply may occur an effect as same as the forced outage of generator in viewpoint of adequacy reliability of system. While a two-state model is well suited for modeling conventional generators, a multi-state model is needed to model the SCGs due to the random variation of solar radiation. This makes the method of calculating reliability evaluation indices of the SCG different from the conventional generator. After identifying the typical pattern of the SR probability distribution function(pdf) from SR actual data, this paper describes modelling, methodology and details process for reliability evaluation of the solar cell generators integrated with power system. Two test results indicate the viability of the proposed method.

뇌파를 이용한 허리 압박감 평가 기술 (Evaluation of Waist Pressure Using Electroencephalogram(EEG) Signal)

  • 김동준;우승진
    • 전기학회논문지
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    • 제60권6호
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    • pp.1190-1195
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    • 2011
  • This paper presents a waist pressure evaluation method in human sensibility using a electroencephalogram(EEG) signal. For this objective, a size-controllable waist-belt is used. First of all, EEG signals for relaxed state are acquired. Then, the waist-belt of the subject is tightened about 90% of normal state. After a few minutes, the belt of the subject is released. Some necessary preprocessing is performed on the acquired signals, Linear Prediction (LP) coefficients are utilized as the feature parameters extracting the characteristics of EEG signal, and a multi-layer neural network is used for indicating the state of body pressure. The results of the method showed 77.2% of coincidence with body pressure states. This may be compromising results for ssubject-independent sensibility evaluation using EEG signal.

방수재료의 거동대응성능 시험시 비 구속조건에서의 구조물 거동 대응성능 평가의 한계와 향후 개선 방안 제안 (Limitations of Structural Behavior Response Performance Evaluation for Waterproofing Materials Under Non-Constrained Conditions and Suggestions for Future Improvement Measures)

  • 안기원;오규환;김수연;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2021년도 가을 학술논문 발표대회
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    • pp.212-213
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    • 2021
  • As structure and the waterproofing material are compressed through the backfilling process after the waterproofing material is installed on the underground structure at the actual site, there is a difference between the behavioral response force of the waterproofing material in the compressed state and the behavioral response force in the non-constrained state. In this regard, we will analyze the limitations of the current structural behavioral response evaluation and suggest an improvement plan so that the future test and evaluation environment can be evaluated under conditions similar to the field.

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On-line integration of structural identification/damage detection and structural reliability evaluation of stochastic building structures

  • Lei, Ying;Wang, Longfei;Lu, Lanxin;Xia, Dandan
    • Structural Engineering and Mechanics
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    • 제63권6호
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    • pp.789-797
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    • 2017
  • Recently, some integrated structural identification/damage detection and reliability evaluation of structures with uncertainties have been proposed. However, these techniques are applicable for off-line synthesis of structural identification and reliability evaluation. In this paper, based on the recursive formulation of the extended Kalman filter, an on-line integration of structural identification/damage detection and reliability evaluation of stochastic building structures is investigated. Structural limit state is expanded by the Taylor series in terms of uncertain variables to obtain the probability density function (PDF). Both structural component reliability with only one limit state function and system reliability with multi-limit state functions are studied. Then, it is extended to adopt the recent extended Kalman filter with unknown input (EKF-UI) proposed by the authors for on-line integration of structural identification/damage detection and structural reliability evaluation of stochastic building structures subject to unknown excitations. Numerical examples are used to demonstrate the proposed method. The evaluated results of structural component reliability and structural system reliability are compared with those by the Monte Carlo simulation to validate the performances of the proposed method.