• 제목/요약/키워드: Inverse Analysis

검색결과 1,670건 처리시간 0.036초

디지털 흉부 방사선 영상에서 Hybrid Filter와 Inverse Filter를 적용한 종양의 검출능 평가 (Evaluation of Cancer Detection Efficiency by Means of Hybrid and Inverse Filter in Chest Radiography)

  • 김윤영;김태영;김현지;박민석;김정민
    • 대한방사선기술학회지:방사선기술과학
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    • 제36권4호
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    • pp.319-326
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    • 2013
  • 본 연구에서는, 흉부단순사진에 있어서 종양그림자의 검출에 대한 흑백 Inverse image과 Hybrid image의 유용성을 ROC해석으로 검토하였다. 증례의 선택은 일본방사선기술학회가 발행한 표준 Digital 영상 Date Base로부터 30장을 선택 하여 original image로 하였다. c언어를 통해 Inverse image는 60장, Hybrid image는 30장 제작하였다. 실험방법으로 연속 판독실험을 하였고, ROC실험 display program은 Matlap을 통하여 작성하였다. 관찰자의 수는 Inverse image의 경우 방사선사 5명과 방사선의 2명, 합계 7명으로 실험하였다. Hybrid 영상의 경우, 방사선 전공자 3명과 숙련된 방사선사 2명, 합계 5명으로 실험하였다. ROC곡선은 Metz가 작성한 ROCKIT Program을 이용하여 구하였다. Inverse image의 경우 관찰자 7명 전원, 방사선과의 2명, 방사선사 5명의 평균 ROC곡선의 Az는 각각 original image의 0.742, 0.793, 0.721에서, Inverse image의 0.775, 0.821, 0.753까지로, 통계적 유의차로 증가하였다. Hybrid image의 경우 관찰자 5명 전원, 숙련된 방사선사 2명, 방사선학 전공자 3명의 평균 ROC곡선의 Az는 각각 original image의 0.525, 0.491, 0.5478에서, Hybrid 영상의 0.4868, 0.539, 0.450로 변화 하였다. 결론적으로, 흉부단순사진에서 종양의 검출에 관하여, Inverse image은 유의하지만, Hybrid 영상의 경우 유의한 차이가 나타나지 않았다.

Variable Selection in Sliced Inverse Regression Using Generalized Eigenvalue Problem with Penalties

  • Park, Chong-Sun
    • Communications for Statistical Applications and Methods
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    • 제14권1호
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    • pp.215-227
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    • 2007
  • Variable selection algorithm for Sliced Inverse Regression using penalty function is proposed. We noted SIR models can be expressed as generalized eigenvalue decompositions and incorporated penalty functions on them. We found from small simulation that the HARD penalty function seems to be the best in preserving original directions compared with other well-known penalty functions. Also it turned out to be effective in forcing coefficient estimates zero for irrelevant predictors in regression analysis. Results from illustrative examples of simulated and real data sets will be provided.

Bayesian Testing for the Equality of Two Inverse Gaussian Populations with the Fractional Bayes Factor

  • Ko, Jeong-Hwan
    • Journal of the Korean Data and Information Science Society
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    • 제16권3호
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    • pp.539-547
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    • 2005
  • We propose the Bayesian testing for the equality of two independent Inverse Gaussian population means using the fractional Bayesian factors suggested by O' Hagan(1995). As prior distribution for the parameters, we assumed the noninformative priors. In order to investigate the usefulness of the proposed Bayesian testing procedures, the behaviors of the proposed results are examined via real data analysis.

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Weak Strictly Persistence Homeomorphisms and Weak Inverse Shadowing Property and Genericity

  • Honary, Bahman;Bahabadi, Alireza Zamani
    • Kyungpook Mathematical Journal
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    • 제49권3호
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    • pp.411-418
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    • 2009
  • In this paper we introduce the notions of strict persistence and weakly strict persistence which are stronger than those of persistence and weak persistence, respectively, and study their relations with shadowing property. In particular, we show that the weakly strict persistence and the weak inverse shadowing property are locally generic in Z(M).

ON A FAST ITERATIVE METHOD FOR APPROXIMATE INVERSE OF MATRICES

  • Soleymani, Fazlollah
    • 대한수학회논문집
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    • 제28권2호
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    • pp.407-418
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    • 2013
  • This paper studies a computational iterative method to find accurate approximations for the inverse of real or complex matrices. The analysis of convergence reveals that the method reaches seventh-order convergence. Numerical results including the comparison with different existing methods in the literature will also be considered to manifest its superiority in different types of problems.

산업용 FANUC robot의 빠른 역기구학에 관한 연구 (A fast inverse kinematic analysis of industrial FANUC robot)

  • 박형준;전종욱;이쾌희
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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    • pp.953-958
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    • 1992
  • This paper deals with the solution of inverse kinematics of the industrial FANUC robot with IBM PC386. The inverse kinematics of FANUC robot cannot be solved by the algebraical method, because arm matirix T$_{6}$ is very complex and 6-joint angles are associated with the position and the approach of end-effector. Instead we fuund otehr 5-joint angle by and algebraical method after finding .THETA.$_{1}$ value by a numerical method.d.

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열전도의 역문제 방법을 이용한 대형 LPG 엔진 피스톤의 열부하 해석 (Analysis of Thermal Loading of a Large LPG Engine Piston Using the Inverse Heat Conduction Method)

  • 박철우;이부윤
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2006년도 정기 학술대회 논문집
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    • pp.820-827
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    • 2006
  • The convection heat transfer coefficients on the top surface of a large liquid petroleum liquid injection(LPLi) engine piston are analyzed by solving an inverse thermal conduction problem. The heat transfer coefficients are numerically found so that the difference between analyzed temperatures from the finite element method and measured temperatures is minimized. Using the resulting heat transfer coefficients as the boundary condition, temperature of a large LPLi engine piston is analyzed.

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구속된 시스템 운동방정식의 수치해석에 관한 연구 (A Study on Numerical Analysis of Equation of Motion for Constrained Systems)

  • 은희창;정헌수
    • 소음진동
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    • 제7권5호
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    • pp.773-780
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    • 1997
  • Using Generalized Inverse Method presented by Udwadia and Kalaba in 1992, we can obtain equations to exactly describe the motion of constrained systems. When the differential equations are numerically integrated by any numerical integration scheme, the numerical results are generally found to veer away from satisfying constraint equations. Thus, this paper deals with the numerical integration of the differential equations describing constrained systems. Based on Baumgarte method, we propose numerical methods for reducing the errors in the satisfaction of the constraints.

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절연형 Inverse-SEPIC의 동적모델 및 제어특성 (Control Characteristics of Isolated Inverse-SEPIC)

  • 박한얼;김은석;김수석;송중호
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2007년도 하계학술대회 논문집
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    • pp.26-28
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    • 2007
  • Design equations of II-SEPIC (Isolated Inverse-SEPIC) are derived and its dynamic model is also made using state-space averaging method in this paper. II-SEPIC is comprehensively investigated through the frequency response analysis, compared with those of I-SEPIC (Isolated SEPIC).

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INVERSE PROBLEM FOR STOCHASTIC DIFFERENTIAL EQUATIONS ON HILBERT SPACES DRIVEN BY LEVY PROCESSES

  • N. U., Ahmed
    • Nonlinear Functional Analysis and Applications
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    • 제27권4호
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    • pp.813-837
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    • 2022
  • In this paper we consider inverse problem for a general class of nonlinear stochastic differential equations on Hilbert spaces whose generating operators (drift, diffusion and jump kernels) are unknown. We introduce a class of function spaces and put a suitable topology on such spaces and prove existence of optimal generating operators from these spaces. We present also necessary conditions of optimality including an algorithm and its convergence whereby one can construct the optimal generators (drift, diffusion and jump kernel).