• Title/Summary/Keyword: Fitting Model

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Bayesian Modeling of Mortality Rates for Colon Cancer

  • Kim Hyun-Joong
    • Communications for Statistical Applications and Methods
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    • v.13 no.1
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    • pp.177-190
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    • 2006
  • The aim of this study is to propose a Bayesian model for fitting mortality rate of colon cancer. For the analysis of mortality rate of a disease, factors such as age classes of population and spatial characteristics of the location are very important. The model proposed in this study allows the age class to be a random effect in addition to its conventional role as the covariate of a linear regression, while the spatial factor being a random effect. The model is fitted using Metropolis-Hastings algorithm. Posterior expected predictive deviances, standardized residuals, and residual plots are used for comparison of models. It is found that the proposed model has smaller residuals and better predictive accuracy. Lastly, we described patterns in disease maps for colon cancer.

Analysis of Stratified Lake using an Eddy Diffusion and a Mixed-layer Models

  • Kim, Kyung-sub
    • Korean Journal of Hydrosciences
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    • v.8
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    • pp.111-123
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    • 1997
  • A one-dimensional eddy diffusion model and a mixed-layer model are developed and applied to simulate the vertical temperature profiles in lakes. Also the running result of each method are compared and analyzed. In an eddy diffusion model, molecular diffusivity is neglected and eddy diffusivity which does not need lake-specific fitting parameter and constant lake's level are applied. The heat exchanges at the water surface and the bottom are formulated by the energy balance and zero energy gradient, respectively. In a mixed-layer model, two layers approach which has a constant thickness is adopted. The application of these models which use explicit finite difference and Runge-Kutta methods respectively demonstrates that the models simulate water temperatures efficiently.

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Effect on characteristics of thrust forte using arc type tester in linear induction motor (선형 유도 전동기의 회전형 시험기가 추력 특성에 미치는 영향)

  • Ham, Sang-Hwan;Lee, Sung-Gu;Lee, Hyung-Woo;Lee, Ju
    • Proceedings of the KSR Conference
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    • 2009.05a
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    • pp.1661-1666
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    • 2009
  • This paper is analyzed the effect on characteristics of thrust force of linear induction motor(LIM) by arc type tester. Many kinds of tester have a rotational shape because of a finite length of railroad. Whereas effects by using rotational type tester are generally unknown. For reason of that, this paper is analyzed the effect on characteristics by rotational type tester using 2D finite element method(FEM), and then is compared a thrust force between linear type tester and rotational type tester. Analysis model is decided by numerical modeling for fitting the LIM for propulsion system of light rail, and it is changed to proper arc model. And then we analyzed the arc and the linear model. Consequently, arc type tester is not only useful experiment but also efficient simulation method, and small error is occurred between linear and arc model.

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Indirect Detection of Rotor Position of Switched Reluctance Motor Based on Flux Linkage Analytic Model

  • Zhou, Yongqin;Hu, Bo;Wang, Hang;Jin, Ningzhi;Zhou, Meilan
    • Journal of Electrical Engineering and Technology
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    • v.13 no.2
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    • pp.829-837
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    • 2018
  • In this paper, a flux linkage model based on four magnetization curves fitting is proposed for three-phase 12/8 switched reluctance motor (SRM), with the analysis of the basic principle of flux detection method and function analysis method. In the model, the single value function mapping relationship between position angle and flux is established, which can achieve a direct estimation of rotor position. The realization scheme of SRM indirect position detection system is presented. It is proved by simulation and experiment that the proposed scheme is suitable for rotor position detection of SRM, and has high accuracy of position estimation.

Modified SPICE BSIM3v3 Model for RF MOSFET IC Design (RF MOSFET IC 설계를 위한 수정된 SPICE BISM3v3 모델)

  • Kim, Jong-Hyuck;Lee, Seong-Hearn;Kim, Young-Wug
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.545-546
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    • 2006
  • The improved model that external capacitances are connected to a conventional BSIM3v3 RF Macro model with Rg and Rsub is developed in this paper. The extracted external capacitances and resistances are modeled by scalable fitting equations. The modeled S-parameters of $0.13{\mu}m$ NMOSFET agree well with measured ones from 10MHz to 10GHz, verifying the accuracy of the improved model.

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AN ANALYTICAL DC MODEL FOR HEMTS (헴트 소자의 해석적 직류 모델)

  • Kim, Yeong-Min
    • ETRI Journal
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    • v.11 no.2
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    • pp.109-119
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    • 1989
  • Based on the 2-dimensional charge-control simulation[4], a purely analytical model for MODFET's is proposed. In this model, proper treatment of the diffusion effect in the 2-DEG transport due to the gradual channel opening along the 2-DEG channel was made to explain the enhanced mobility and increased thershold voltage. The channel thickness and gate capacitance are experssed as functions of gate vlotage including subthreshold characteristics of the MODFET's analytically. By introducing the finite channel opening and an effective channel-length modulation, the slope of the saturation region of the I-V curves was modeled. The smooth transition of the I-V curves from linear-to-saturation region of the I-V curves was possible using the continuous Troffimenkoff-type of field-dependent mobility. Furthermore, a correction factor f was introduced to account for the finite transtition section forming between the GCA and the saturated section. This factor removes the large discrepanicies in the saturation region fo the I-V curves presicted by existing 1-dimensional models. The fitting parameters chosen in our model were found to be predictable and vary over relatively small range of values.

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Parameter Calibration of Laser Scan Camera for Measuring the Impact Point of Arrow (화살 탄착점 측정을 위한 레이저 스캔 카메라 파라미터 보정)

  • Baek, Gyeong-Dong;Cheon, Seong-Pyo;Lee, In-Seong;Kim, Sung-Shin
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.1
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    • pp.76-84
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    • 2012
  • This paper presents the measurement system of arrow's point of impact using laser scan camera and describes the image calibration method. The calibration process of distorted image is primarily divided into explicit and implicit method. Explicit method focuses on direct optical property using physical camera and its parameter adjustment functionality, while implicit method relies on a calibration plate which assumed relations between image pixels and target positions. To find the relations of image and target position in implicit method, we proposed the performance criteria based polynomial theorem model that overcome some limitations of conventional image calibration model such as over-fitting problem. The proposed method can be verified with 2D position of arrow that were taken by SICK Ranger-D50 laser scan camera.

Bayesian Curve-Fitting in Semiparametric Small Area Models with Measurement Errors

  • Hwang, Jinseub;Kim, Dal Ho
    • Communications for Statistical Applications and Methods
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    • v.22 no.4
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    • pp.349-359
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    • 2015
  • We study a semiparametric Bayesian approach to small area estimation under a nested error linear regression model with area level covariate subject to measurement error. Consideration is given to radial basis functions for the regression spline and knots on a grid of equally spaced sample quantiles of covariate with measurement errors in the nested error linear regression model setup. We conduct a hierarchical Bayesian structural measurement error model for small areas and prove the propriety of the joint posterior based on a given hierarchical Bayesian framework since some priors are defined non-informative improper priors that uses Markov Chain Monte Carlo methods to fit it. Our methodology is illustrated using numerical examples to compare possible models based on model adequacy criteria; in addition, analysis is conducted based on real data.

Rationally modeling collapse due to bending and external pressure in pipelines

  • Nogueira, Andre C.
    • Earthquakes and Structures
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    • v.3 no.3_4
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    • pp.473-494
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    • 2012
  • The capacity of pipelines to resist collapse under external pressure and bending moment is a major aspect of deepwater pipeline design. Existing design codes present interaction equations that quantify pipeline capacities under such loadings, although reasonably accurate, are based on empirical data fitting of the bending strain, and assumed simplistic interaction with external pressure collapse. The rational model for collapse of deepwater pipelines, which are relatively thick with a diameter-to-thickness ratio less than 40, provides a unique theoretical basis since it is derived from first principles such as force equilibrium and compatibility equations. This paper presents the rational model methodology and compares predicted results and recently published full scale experimental data on the subject. Predictive capabilities of the rational model are shown to be excellent. The methodology is extended for the problem of pipeline collapse under point load, longitudinal bending and external pressure. Due to its rational derivation and excellent prediction capabilities, it is recommended that design codes adopt the rational model methodology.

Mobile Palmprint Segmentation Based on Improved Active Shape Model

  • Gao, Fumeng;Cao, Kuishun;Leng, Lu;Yuan, Yue
    • Journal of Multimedia Information System
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    • v.5 no.4
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    • pp.221-228
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    • 2018
  • Skin-color information is not sufficient for palmprint segmentation in complex scenes, including mobile environments. Traditional active shape model (ASM) combines gray information and shape information, but its performance is not good in complex scenes. An improved ASM method is developed for palmprint segmentation, in which Perux method normalizes the shape of the palm. Then the shape model of the palm is calculated with principal component analysis. Finally, the color likelihood degree is used to replace the gray information for target fitting. The improved ASM method reduces the complexity, while improves the accuracy and robustness.