• 제목/요약/키워드: Rule of Mixture

검색결과 259건 처리시간 0.025초

혼합모델 및 다중 가설 검정을 이용한 신호와 잡음의 분류 (Separating Signals and Noises Using Mixture Model and Multiple Testing)

  • 박해상;유시원;전치혁
    • 응용통계연구
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    • 제22권4호
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    • pp.759-770
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    • 2009
  • 본 논문은 신호와 잡음이 혼합된 관측치로부터 신호 관측치를 분류하는 문제를 다룬다. 잡음은 가우시안 분포를 따르고 신호는 감마 분포를 따른다고 가정할 때 관측치의 분포는 가우시안과 감마의 혼합 분포를 따르게 된다. EM 알고리즘을 통해 혼합 모델의 모수를 추정하고 신호 및 잡음을 분류하는 것을 다중 가설 검정으로 간주하여 베이즈 오류를 바탕으로 분류를 위한 경계치를 설정한다. 제안하는 방법을 분광 데이터에 근거하여 철강 제품에서 개재물 유무를 검출하는 문제에 적용하였고 별도의 시뮬레이션 데이터를 통해 성능의 우수성을 보였다.

Lindley Type Estimators When the Norm is Restricted to an Interval

  • Baek, Hoh-Yoo;Lee, Jeong-Mi
    • Journal of the Korean Data and Information Science Society
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    • 제16권4호
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    • pp.1027-1039
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    • 2005
  • Consider the problem of estimating a $p{\times}1$ mean vector $\theta(p\geq4)$ under the quadratic loss, based on a sample $X_1$, $X_2$, $\cdots$, $X_n$. We find a Lindley type decision rule which shrinks the usual one toward the mean of observations when the underlying distribution is that of a variance mixture of normals and when the norm $\parallel\;{\theta}-\bar{{\theta}}1\;{\parallel}$ is restricted to a known interval, where $bar{{\theta}}=\frac{1}{p}\;\sum\limits_{i=1}^{p}{\theta}_i$ and 1 is the column vector of ones. In this case, we characterize a minimal complete class within the class of Lindley type decision rules. We also characterize the subclass of Lindley type decision rules that dominate the sample mean.

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Phase Equilibrium of Binary Mixture for the (propylene oxide + 1-pentanol) System at Several Temperatures

  • Kim, Jeong-lae;Kim, Hakmin;Park, Su In;An, Gyu Min;Kim, Min Gi;Shin, Moon Sam
    • Korean Chemical Engineering Research
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    • 제57권1호
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    • pp.73-77
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    • 2019
  • Isothermal (vapor + liquid) equilibrium data measurements were undertaken for the binary mixtures of (propylene oxide + 1-pentanol) system at three different temperatures (303.15, 318.15, and 333.15) K. The Peng-Robinson-Stryjek-Vera equation of state (PRSV EOS) was used to correlate the experimental data. The van der Waals one-fluid mixing rule was used for the vapor phase and the Wong-Sandler mixing rule, which incorporates the non-random two liquid (NRTL) model, the universal quasi-chemical (UNIQUAC) model and the Wilson model, was used for the liquid phase. The experimental data were in good agreement with the correlation results.

James-Stein Type Estimators Shrinking towards Projection Vector When the Norm is Restricted to an Interval

  • Baek, Hoh Yoo;Park, Su Hyang
    • 통합자연과학논문집
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    • 제10권1호
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    • pp.33-39
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    • 2017
  • Consider the problem of estimating a $p{\times}1$ mean vector ${\theta}(p-q{\geq}3)$, $q=rank(P_V)$ with a projection matrix $P_v$ under the quadratic loss, based on a sample $X_1$, $X_2$, ${\cdots}$, $X_n$. We find a James-Stein type decision rule which shrinks towards projection vector when the underlying distribution is that of a variance mixture of normals and when the norm ${\parallel}{\theta}-P_V{\theta}{\parallel}$ is restricted to a known interval, where $P_V$ is an idempotent and projection matrix and rank $(P_V)=q$. In this case, we characterize a minimal complete class within the class of James-Stein type decision rules. We also characterize the subclass of James-Stein type decision rules that dominate the sample mean.

2.5D Cf/SiCm 복합재의 기계적 물성 시험과 탄소성 모델링을 통한 유한요소해석 (Finite Element Analysis Through Mechanical Property Test and Elasto-plastic Modeling of 2.5D Cf/SiCm Composite Analysis)

  • 이민정;김연태;이연관
    • 한국항공우주학회지
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    • 제48권9호
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    • pp.663-670
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    • 2020
  • 2.5D C/SiC를 적용한 구조물의 거동 특성을 유한요소해석으로 근사하기 위해 기계적 물성 특성화와 모델링 기법에 관한 연구를 수행하였다. 2.5D C/SiC 소재의 거동 특성을 분석하기 위해 인장시험을 수행하였고 수학적 균질화 기법과 수정된 혼합 법칙을 적용하여 2.5D C/SiC를 구성하는 섬유와 기지의 탄성 물성을 정의하였다. 탄소성 거동을 나타내는 기지는 소성 영역의 거동을 bilinear 함수로 근사하고 시험과 해석의 오차를 최소화하여 등가 항복 강도와 등가 소성 강성을 계산하였다. 그리고 2.5D C/SiC의 RVE를 정의하고 수정된 혼합 법칙을 적용하여 유효강성행렬을 계산하는 과정을 ABAQUS의 User-defined subroutine을 통해 구성하였다. 제안된 과정을 바탕으로 정의된 섬유와 기지의 기계적 물성을 적용하여 유한요소해석을 수행한 결과는 시험의 거동을 잘 근사하고 있음을 확인하였다.

Classical shell theory for instability analysis of concrete pipes conveying nanofluid

  • Keikha, Reza;Heidari, Ali;Hosseinabadi, Hamidreza;Haghighi, Mohammad Salkhordeh
    • Computers and Concrete
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    • 제22권2호
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    • pp.161-166
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    • 2018
  • This paper deals with the instability analysis of concrete pipes conveying viscous fluid-nanoparticle mixture. The fluid is mixed by $AL_2O_3$ nanoparticles where the effective material properties of fluid are obtained by mixture rule. The applied force by the internal fluid is calculated by Navier-Stokes equation. The structure is simulated by classical cylindrical shell theory and using energy method and Hamilton's principle, the motion equations are derived. Based on Navier method, the critical fluid velocity of the structure is calculated and the effects of different parameters such as fluid velocity, volume percent of nanoparticle in fluid and geometrical parameters of the pipe are considered. The results present that with increasing the volume percent of nanoparticle in fluid, the critical fluid velocity increase.

FEM에 의한 CRALL재의 노치강도 해석(I) (Notched Strength Analysis of CRALL Materials by FEM (I))

  • 윤한기
    • 한국해양공학회지
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    • 제13권2호통권32호
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    • pp.41-50
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    • 1999
  • As for the properties on both the aluminum and the CFRP which are used to make A17075/CFRP multi-layered hybrid composites, CRALL(carbon reinforced aluminum laminate). In the CRALL specimen for rule of mixture, we were analyzed notched strength by finite element method. The results obtained from FEM analysis are as follows; In the unnotch CRALL specimen, the stresses CFRP, epoxy, Al 7075 obtained by finite element method strength solution for A/C0001, when strain is 0.28%, are 1400MPa, 38MPa, 411MPa. respectively and for A/C9991, when strain 0.48%, are 392MPa, 26MPa and 321Mpa, respectively. the solpe of the stress-strain curve by FEM increases in keeping with the hole size and the yield strain decrease to 36% and 55% for A/C9993 and A/C9991 respectively.

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Improvement of the Modified James-Stein Estimator with Shrinkage Point and Constraints on the Norm

  • Kim, Jae Hyun;Baek, Hoh Yoo
    • 통합자연과학논문집
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    • 제6권4호
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    • pp.251-255
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    • 2013
  • For the mean vector of a p-variate normal distribution ($p{\geq}4$), the optimal estimation within the class of modified James-Stein type decision rules under the quadratic loss is given when the underlying distribution is that of a variance mixture of normals and when the norm ${\parallel}{\theta}-\bar{\theta}1{\parallel}$ it known.

하이브리드 복합재료 튜브의 Pultrusion 성형공정연구 (A Study on the Pultrusion of Hybrid Composite Tube)

  • 성대영;김태욱;이광주
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2001년도 춘계학술발표대회 논문집
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    • pp.180-183
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    • 2001
  • Glass fiber reinforced plastic(CFHP) tent pole fabricated by the pultrusion process with unidirectional glass fiber is two times as heavy as aluminum tent pole owing to the low specific modulus The first objective of this research is the design the high strength and light weight tent pole compete with. the second is the develope glass fiber carbon fiber hybrid tent pole pultrusion process. the third is the evaluate the mechanical properties of the hybrid tent pole compare to these of the duralumin tent pole.

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역확산을 고려한 이원합금의 비평형 수지상응고 해석 (Analysis on the non-equilibrium dendritic solidification of a binary alloy with back diffusion)

  • 정재동;유호선;이준식
    • 대한기계학회논문집B
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    • 제20권10호
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    • pp.3361-3370
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    • 1996
  • Micro-Macro approach is conducted for the mixture solidification to handle the closely linked phenomena of microscopic solute redistribution and macroscopic solidification behavior. For this purpose, present work combines the efficiency of mixture theory for macro part and the capability of microscopic analysis of two-phase model for micro part. The micro part of present study is verified by comparison with experiment of Al-4.9 mass% Cu alloy. The effect of back diffusion on the macroscopic variables such as temperature and liquid concentration, is appreciable. The effect, however, is considerable on the mixture concentration and eutectic fraction which are indices of macro and micro segregation, respectively. According to the diffusion time, the behavior near the cooling wall where relatively rapid solidification permits short solutal diffusion time, approaches Scheil equation limit and inner part approaches lever rule limit.