• Title/Summary/Keyword: Linear Structure Model

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Bayesian forecasting approach for structure response prediction and load effect separation of a revolving auditorium

  • Ma, Zhi;Yun, Chung-Bang;Shen, Yan-Bin;Yu, Feng;Wan, Hua-Ping;Luo, Yao-Zhi
    • Smart Structures and Systems
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    • v.24 no.4
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    • pp.507-524
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    • 2019
  • A Bayesian dynamic linear model (BDLM) is presented for a data-driven analysis for response prediction and load effect separation of a revolving auditorium structure, where the main loads are self-weight and dead loads, temperature load, and audience load. Analyses are carried out based on the long-term monitoring data for static strains on several key members of the structure. Three improvements are introduced to the ordinary regression BDLM, which are a classificatory regression term to address the temporary audience load effect, improved inference for the variance of observation noise to be updated continuously, and component discount factors for effective load effect separation. The effects of those improvements are evaluated regarding the root mean square errors, standard deviations, and 95% confidence intervals of the predictions. Bayes factors are used for evaluating the probability distributions of the predictions, which are essential to structural condition assessments, such as outlier identification and reliability analysis. The performance of the present BDLM has been successfully verified based on the simulated data and the real data obtained from the structural health monitoring system installed on the revolving structure.

Development of Runoff Hydrograph Model for the Derivation of Optimal Design Flood of Agricultural Hydraulic Structures(1) (농업수리구조물의 적정설계홍수량 유도를 위한 유출수문곡선모형의 개발(I))

  • 이순혁;박명근;맹승진
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.37 no.3_4
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    • pp.34-47
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    • 1995
  • It is experienced fact as a regular annual event that the structure to he designed on unreasonable flood for the agricultural structures including reservoirs have been brought not only loss of lives, but also enormous property damage. For the solution of this problem at issue, this study was conducted to develop an optimal runoff hydrograph model by comparison of the peak flows and time to peak between observed and simulated flows derived by linear time-invariant and linear time-variant models under the condition of having a short duration of heavy rainfall with uniform rainfall intensity at nine small watersheds which are within the range of 55.9 to 140.7 square kilometers in area in Han, Geum, Nagdong and Yeongsan Rivers. The results obtained through this study can be summarized as follows. 1. Storage constants and Gamma function arguments were calculated within the range of 1.2 to 6.42 and of 1.28 to 8.05 respectively by the moment method as the parameters for the analysis of runoff hydrograph based on linear time-invariant model. 2. Parameters for both linear time-invariant and linear time-variant models were calibrated with nine gaged watershed data, using a trial and error method. The resulting parameters including Gamma function argument, N and storage constant, K for linear time-invariant model were related statistically to watershed characteristic variables such as area, slope, length of main stream and the centroid length of the basin. 3. Average relative errors of the simulated peak discharge of calibrated runoff hydrographs by using linear time-variant and linear time-invariant models were shown to be 0.75 and 5.42 percent respectively to the peak of observed runoff hydrographs. Correlation coefficients for the statistical analysis in the same condition were shown to be 0.999 and 0.978 with a high significance respectively. Therefore, it can be concluded that the accuracy of a linear time-variant model is approaching more closely to the observed runoff hydrograph than that of a linear time-invariant model in the applied watersheds. 4. Average relative errors of the time to peak of calibrated runoff hydrographs by using linear time-variant and linear time-invariant models were shown to be 16.44 and 19.89 percent respectively to the time to peak of observed runoff hydrographs. Correlation coefficients in the same condition were also shown to be 0.999 and 0.886 with a high significance respectively. 5. It can be seen that the shape of simulated hydrograph based on a linear time- variant model is getting closer to the observed runoff hydrograph than that of a linear time-invariant model in the applied watersheds. 6. Two different models were verified with different rainfall-runoff events from data for the calibration by relative error and correlation analysis. Consequently, it can be generally concluded that verification results for the peak discharge and time to peak of simulated runoff hydrographs were in good agreement with those of calibrated runoff hydrographs.

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Feature Selection and Classification of Protein CDS Using n-Block substring weighted Linear Model (N-Block substring 가중 선형모형을 이용한 단백질 CDS의 특징 추출 및 분류)

  • Choi, Seong-Yong;Kim, Jin-Su;Han, Seung-Jin;Choi, Jun-Hyeog;Rim, Kee-Wook;Lee, Jung-Hyun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.5
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    • pp.730-736
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    • 2009
  • It is more important to analysis of huge gemonics data in Bioinformatics. Here we present a novel datamining approach to predict structure and function using protein's primnary structure only. We propose not also to develope n-Block substring search algorithm in reducing enormous search space effectively in relation to feature selection, but to formulate weighted linear algorithm in a prediction of structure and function of a protein using primary structure. And we show efficient in protein domain characterization and classification by calculation weight value in determining domain association in each selected substring, and also reveal that more efficient results are acquired through claculated model score result in an inference about degree of association with each CDS(coding sequence) in domain.

Nonlinear System Parameter Identification Using Finite Element Model (유한요소모델을 이용한 비선형 시스템의 매개변수 규명)

  • Kim, Won-Jin;Lee, Bu-Yun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.6 s.177
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    • pp.1593-1600
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    • 2000
  • A method based on frequency domain approaches is presented for the nonlinear parameters identification of structure having nonlinear joints. The finite element model of linear substructure is us ed to calculating its frequency response functions needed in parameter identification process. This method is easily applicable to a complex real structure having nonlinear elements since it uses the frequency response function of finite element model. Since this method is performed in frequency domain, the number of equations required to identify the unknown parameters can be easily increased as many as it needed, just by not only varying excitation amplitude but also selecting excitation frequencies. The validity of this method is tested numerically and experimentally with a cantilever beam having the nonlinear element. It was verified through examples that the method is useful to identify the nonlinear parameters of a structure having arbitary nonlinear boundaries.

Study on the FEA Model of the Linear Pulse Motor for Railway Application and Reduction of Thrust Ripple (철도차량 추진용 Linear Pulse Motor의 축소 모델 해석 및 추력 리플 저감 연구)

  • Seol, Hyun-Soo;Lee, Gang-Seok;Jeong, Geochul;Lee, Ju
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.6
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    • pp.981-987
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    • 2017
  • In this paper, we describe the LPM structure with a two-phase, which is not used previously, and explain its operation principle. In order to predict the accurate performance of LPM reduction model, finite element model was derived and the back EMF of LPM reduction model was measured and compared. In order to investigate the thrust and normal force of the LPM reduction model, a driving circuit capable of applying two-phase pulse currents was constructed and the performance was predicted in conjunction with the finite element analysis model. Finally, the design considering actual LPM size was performed. Since the size of the reduction model is small, the field could be made of a permanent magnet. However, it is almost impossible to manufacture a permanent magnet to match the size and capacity of a real LPM for a vehicle, in terms of cost and writing. Therefore, the actual vehicle LPM was replaced by wound type that generates a magnetic field by applying current to the field winding, and the final model was derived using the reaction surface method.

A Mean of Structural equation modeling on AMOS Software (AMOS 소프트웨어에서 구현되는 구조방정식 모형과 의미)

  • Kim, Kyung-Tae
    • Proceedings of the Korean Association for Survey Research Conference
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    • 2007.11a
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    • pp.55-65
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    • 2007
  • In this research, it will be examined on mathematical model of AMOS software program that ues for Covariance Structure Analysis. if we have not understood to mathematical model of Covariance Structure, we fail to understand Structural equation modeling. Similarly If We were not understand to mathematical model of AMOS Software, we do not use Software adequately. Therefore we examine two sorts of Software that be designed for Structural equation modeling or Covariance Structure Analysis. In this research, We will focus on 8 assumption of Structural equation modeling and compare AMOS(Analysis of MOment Structure) program with LISREL(Linear Structure RELation) program. We found that A Program of AMOS Software have materialized with RAM(Reticular Action Model).

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On the ridge estimations with the correlated error structure

  • Won, Byung-Chool
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1990.04a
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    • pp.263-271
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    • 1990
  • In this paper, we shall construct a ridge estimator in a multiple linear model with the correlated error structure. The existence of the biasing parameter satisfying the Mean Squared Error Criterion is also proved. Furthermore, we shall determine the value of shrinkage factors by the iteration method.

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On the Ridge Estimations with the Corrlated Error Structure

  • Won, Byung Chool;Kim, Hae Kyung
    • Honam Mathematical Journal
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    • v.9 no.1
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    • pp.99-111
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    • 1987
  • In this paper we shall construct a ridge estimator in a multiple linear model with the correlated error structure. The existence of the biasing parameter satisfying the Mean Squared Error Criterion is also proved. Furthermore, we shall determine the value of shrinkage factors by the iteration method.

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Design Rules of Hybrid Stepping Machine for Free Piston Engine

  • Jeong, Sung-In
    • Journal of Electrical Engineering and Technology
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    • v.12 no.3
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    • pp.1219-1226
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    • 2017
  • This paper presents the hybrid stepping machine for linear oscillating generators. The focus of the work is the suggestion of the improved model through the comparison of proposed models ; new flux concentrating PMs mover of the hybrid stepping generator is proposed based on the symmetrical and non-symmetrical stator cores of the surface mounted PMs mover, and non-slanted PMs and slanted PMs of the flux concentrating PMs mover. It is achieved using equivalent magnetic circuit considering leakage elements. Finally, this study suggests new hybrid stepping structure of linear oscillating generator.

CERES Plot in Generalized Linear Models

  • Kahng, Myung-Wook;Lee, Eun Jeong
    • Communications for Statistical Applications and Methods
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    • v.11 no.3
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    • pp.575-582
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    • 2004
  • We explore the structure and usefulness of CERES plot as a basic tool for dealing with curvature as a function of the new predictor in generalized linear models. If a predictor has a nonlinear effect and there are nonlinear relationships among the predictors, the partial residual plot and augmented partial residual plot are not able to display the correct functional form of the predictor. Unlike these plots, the CERES plot can show the correct form. This is illustrated by simulated data.