• Title, Summary, Keyword: linear model

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A Linear Reservoir Model with Kslman Filter in River Basin (Kalman Filter 이론에 의한 하천유역의 선형저수지 모델)

  • 이영화
    • Journal of Environmental Science International
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    • v.3 no.4
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    • pp.349-356
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    • 1994
  • The purpose of this study is to develop a linear reservoir model with Kalman filter using Kalman filter theory which removes a physical uncertainty of :ainfall-runoff process. A linear reservoir model, which is the basic model of Kalman filter, is used to calculate runoff from rainfall in river basin. A linear reservoir model with Kalman filter is composed of a state-space model using a system model and a observation model. The state-vector of system model in linear. The average value of the ordinate of IUH for a linear reservoir model with Kalman filter is used as the initial value of state-vector. A .linear reservoir model with Kalman filter shows better results than those by linear reserevoir model, and decreases a physical uncertainty of rainfall-runoff process in river basin.

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A study on Parameters of Linear reservoir models (선형저수지 모형의 매개변수연구)

  • 고재웅;서영제
    • Water for future
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    • v.20 no.3
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    • pp.229-235
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    • 1987
  • The purpose of this study is to estimate the parameters of linear reservoir models in order to derive the Instantaneous unit hydrograph from a given small experimental watershed. The linear reservoir model is a conceptual model, consisting of cascade or parallel equal linear reservoirs, preceded by a linear channel which involved Nash, SLR(single linear reservoir) and 2-PLR(two-parallel linear Reservoir) model. the Nash model have two parameters N and K, single linear reseroir has one parameter $K_I$ and two-parallel linear reservoirs have two parameters $K_1,\;K_2$; where N denote the number of reservoirs and K is the storage coefficient of each reservoirs.

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Trajectory Following Control Using Cogging Force Model in Linear Positioning System

  • Chung, Myung-Jin;Gweon, Dae-Gab
    • International Journal of Precision Engineering and Manufacturing
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    • v.3 no.3
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    • pp.62-68
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    • 2002
  • To satisfy the requirement of the one axis linear positioning system, which is following control of the desired trajectory without following error and is the high positioning accuracy, feed-forward loop having cogging force model is proposed. In the one axis linear positioning system with linear PM motor, cogging force acting as disturbance is modeled analytically. Analytic model of cogging force is verified by result measured from positioning system constructed with linear PM motor. Measured result is very similar with proposed analytic model. Cogging force model is used as feet forward loop in control scheme of linear positioning system. Cogging force feed-forward'loop is obtained from analytic model of cogging farce. Trajectory following error is reduced from 300nm to 100nm by applying the proposed cogging farce feed-forward loop. By using analytic model of cogging force, the control scheme is simplified. Also this analytic model is applicable to calculation of characteristic value of positioning system in design process.

선형 저수지 유형의 parameter 연구

  • 서영재;고재웅
    • Proceedings of the Korea Water Resources Association Conference
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    • pp.151-158
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    • 1987
  • The purpose of thes study is to estimate the parameters of linear reservoir models in order to derive the instantaneous unit hydrograph from a given small experimental watershed. The linear reservoir model is a conceptual model, consisting of cascade or parallel equal linear reservoirs, preceded by a linear channel which involved NASH, SLR(single linear reservoir)and 2-PLR(two-parallel linear reservoir)model. The NASH model have two parameters N and K, single linear reservoir has one parameter K1 and two-parallel linear reservoirs have two parameters K1, K2;where N denote the number of reservoirs and K is the storage coefficient of each reservoirs.

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Large Robust Designs for Generalized Linear Model

  • Kim, Young-Il;Kahng, Myung-Wook
    • Journal of the Korean Data and Information Science Society
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    • v.10 no.2
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    • pp.289-298
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    • 1999
  • We consider a minimax approach to make a design robust to many types or uncertainty arising in reality when dealing with non-normal linear models. We try to build a design to protect against the worst case, i.e. to improve the "efficiency" of the worst situation that can happen. In this paper, we especially deal with the generalized linear model. It is a known fact that the generalized linear model is a universal approach, an extension of the normal linear regression model to cover other distributions. Therefore, the optimal design for the generalized linear model has very similar properties as the normal linear model except that it has some special characteristics. Uncertainties regarding the unknown parameters, link function, and the model structure are discussed. We show that the suggested approach is proven to be highly efficient and useful in practice. In the meantime, a computer algorithm is discussed and a conclusion follows.

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Variable Selection Theorems in General Linear Model

  • Yoon, Sang-Hoo;Park, Jeong-Soo
    • Proceedings of the Korean Statistical Society Conference
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    • pp.187-192
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    • 2005
  • For the problem of variable selection in linear models, we consider the errors are correlated with V covariance matrix. Hocking's theorems on the effects of the overfitting and the undefitting in linear model are extended to the less than full rank and correlated error model, and to the ANCOVA model

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Normal Mixture Model with General Linear Regressive Restriction: Applied to Microarray Gene Clustering

  • Kim, Seung-Gu
    • Communications for Statistical Applications and Methods
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    • v.14 no.1
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    • pp.205-213
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    • 2007
  • In this paper, the normal mixture model subjected to general linear restriction for component-means based on linear regression is proposed, and its fitting method by EM algorithm and Lagrange multiplier is provided. This model is applied to gene clustering of microarray expression data, which demonstrates it has very good performances for real data set. This model also allows to obtain the clusters that an analyst wants to find out in the fashion that the hypothesis for component-means is represented by the design matrices and the linear restriction matrices.

Review of Spatial Linear Mixed Models for Non-Gaussian Outcomes (공간적 상관관계가 존재하는 이산형 자료를 위한 일반화된 공간선형 모형 개관)

  • Park, Jincheol
    • The Korean Journal of Applied Statistics
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    • v.28 no.2
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    • pp.353-360
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    • 2015
  • Various statistical models have been proposed over the last decade for spatially correlated Gaussian outcomes. The spatial linear mixed model (SLMM), which incorporates a spatial effect as a random component to the linear model, is the one of the most widely used approaches in various application contexts. Employing link functions, SLMM can be naturally extended to spatial generalized linear mixed model for non-Gaussian outcomes (SGLMM). We review popular SGLMMs on non-Gaussian spatial outcomes and demonstrate their applications with available public data.

Effects of the Non-linear Stress-Strain Behavior of RAP Concrete on Structural Responses for Rigid Pavement Application (RAP 콘크리트의 비선형 응력-변형률 특성이 강성포장 구조해석에 미치는 영향)

  • Kim, Kukjoo;Chun, Sanghyun;Park, Bongsuk;Tia, Mang
    • International Journal of Highway Engineering
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    • v.19 no.1
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    • pp.37-44
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    • 2017
  • PURPOSES : This study is primarily focused on evaluating the effects of the non-linear stress-strain behavior of RAP concrete on structural response characteristics as is applicable to concrete pavement. METHODS : A 3D FE model was developed by incorporating the actual stress-strain behavior of RAP concrete obtained via flexural strength testing as a material property model to evaluate the effects of the non-linear stress-strain behavior to failure on the maximum stresses in the concrete slab and potential performance prediction results. In addition, a typical linear elastic model was employed to analyze the structural responses for comparison purposes. The analytical results from the FE model incorporating the actual stress-strain behavior of RAP concrete were compared to the corresponding results from the linear elastic FE model. RESULTS : The results indicate that the linear elastic model tends to yield higher predicted maximum stresses in the concrete as compared to those obtained via the actual stress-strain model. Consequently, these higher predicted stresses lead to a difference in potential performance of the concrete pavement containing RAP. CONCLUSIONS : Analysis of the concrete pavement containing RAP demonstrated that an appropriate analytical model using the actual stress-strain characteristics should be employed to calculate the structural responses of RAP concrete pavement instead of simply assuming the concrete to be a linear elastic material.

Implementation and Verification of Linear Cohesive Viscoelastic Contact Model for Discrete Element Method (선형 부착성 점탄성 접촉모형의 DEM 적용 및 해석적 방법을 이용한 검증)

  • Yun, Tae Young;Yoo, Pyeong Jun
    • International Journal of Highway Engineering
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    • v.17 no.4
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    • pp.25-31
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    • 2015
  • PURPOSES: Implementation and verification of the simple linear cohesive viscoelastic contact model that can be used to simulate dynamic behavior of sticky aggregates. METHODS: The differential equations were derived and the initial conditions were determined to simulate a free falling ball with a sticky surface from a ground. To describe this behavior, a combination of linear contact model and a cohesive contact model was used. The general solution for the differential equation was used to verify the implemented linear cohesive viscoelastic API model in the DEM. Sensitivity analysis was also performed using the derived analytical solutions for several combinations of damping coefficients and cohesive coefficients. RESULTS : The numerical solution obtained using the DEM showed good agreement with the analytical solution for two extreme conditions. It was observed that the linear cohesive model can be successfully implemented with a linear spring in the DEM API for dynamic analysis of the aggregates. CONCLUSIONS: It can be concluded that the derived closed form solutions are applicable for the analysis of the rebounding behavior of sticky particles, and for verification of the implemented API model in the DEM. The assumption of underdamped condition for the viscous behavior of the particles seems to be reasonable. Several factors have to be additionally identified in order to develop an enhanced contact model for an asphalt mixture.