• 제목/요약/키워드: Subspace

검색결과 741건 처리시간 0.031초

물체 추적을 위한 강화된 부분공간 표현 (Enhanced Representation for Object Tracking)

  • 윤석민;유한주;최진영
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
    • /
    • pp.408-410
    • /
    • 2009
  • We present an efficient and robust measurement model for visual tracking. This approach builds on and extends work on subspace representations of measurement model. Subspace-based tracking algorithms have been introduced to visual tracking literature for a decade and show considerable tracking performance due to its robustness in matching. However the measures used in their measurement models are often restricted to few approaches. We propose a novel measure of object matching using Angle In Feature Space, which aims to improve the discriminability of matching in subspace. Therefore, our tracking algorithm can distinguish target from similar background clutters which often cause erroneous drift by conventional Distance From Feature Space measure. Experiments demonstrate the effectiveness of the proposed tracking algorithm under severe cluttered background.

  • PDF

DS/CDMA DMB 하향 링크에서 복잡도가 감소된 블라인드 부분 공간 채널 추정 (Complexity Reduced Blind Subspace Channel Estimation for DS/CDMA DMB Downlink)

  • 양완철;이병섭
    • 한국전자파학회논문지
    • /
    • 제15권9호
    • /
    • pp.863-871
    • /
    • 2004
  • 본 논문에서는 정합 필터 출력을 이용하여 연산 복잡도가 감소된 DS/CDMA DMB 하향 링크 시스템에서의 부분 공간 채널 추정 기법을 제안한다. 연산 복잡도 감소 효과는 채널 벡터의 길이가 짧고 시스템의 부하가 적절할 때 매우 크게 나타난다. 이전에 제안된 부분 공간 채널 추정 알고리즘은 화산 이득이 큰 시스템에서 막대한 연산 복잡도 문제를 겪게 된다. 제안된 알고리즘에 약간의 성능 손실이 발생하지만 데이터 행렬의 길이가 길어지게 되면 그 영향은 미미해진다. 시뮬레이션과 분석적인 MSE 성능의 유도를 통해 성능을 평가한다.

Recursive State Space Model Identification Algorithms Using Subspace Extraction via Schur Complement

  • Takei, Yoshinori;Imai, Jun;Wada, Kiyoshi
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
    • /
    • pp.525-525
    • /
    • 2000
  • In this paper, we present recursive algorithms for state space model identification using subspace extraction via Schur complement. It is shown that an estimate of the extended observability matrix can be obtained by subspace extraction via Schur complement. A relationship between the least squares residual and the Schur complement matrix obtained from input-output data is shown, and the recursive algorithms for the subspace-based state-space model identification (4SID) methods are developed. We also proposed the above algorithm for an instrumental variable (IV) based 4SID method. Finally, a numerical example of the application of the algorithms is illustrated.

  • PDF

정류된 부공간 해석을 이용한 PET 영상 분석 (Rectified Subspace Analysis of Dynamic Positron Emission Tomography)

  • Kim, Sangki;Park, Seungjin;Lee, Jaesung;Lee, Dongsoo
    • 한국정보과학회:학술대회논문집
    • /
    • 한국정보과학회 2002년도 가을 학술발표논문집 Vol.29 No.2 (2)
    • /
    • pp.301-303
    • /
    • 2002
  • Subspace analysis is a popular method for multivariate data analysis and is closely related to factor analysis and principal component analysis (PCA). In the context of image processing (especially positron emission tomography), all data points are nonnegative and it is expected that both basis images and factors are nonnegative in order to obtain reasonable result. In this paper We present a sequential EM algorithm for rectified subspace analysis (subspace in nonnegativity constraint) and apply it to dynamic PET image analysis. Experimental results show that our proposed method is useful in dynamic PET image analysis.

  • PDF

수치적으로 안정한 부분공간 반복법 (Numerically Stable Subspace Iteration Method)

  • 정형조;김만철;박선규;이인원
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 1998년도 가을 학술발표회 논문집
    • /
    • pp.84-91
    • /
    • 1998
  • A numerically stable technique to remove tile limitation in choosing a shift in the subspace iteration method with shift is presented. A major difficulty of the subspace iteration method with shift is that because of singularity problem, a shift close to an eigenvalue can not be used, resulting in slower convergence. This study selves the above singularity problem using side conditions without sacrifice of convergence. The method is always nonsingular even if a shiht is an eigenvalue itself. This is one of tile significant characteristics of the proposed method. The nonsingularity is proved analytically. The convergence of the proposed method is at least equal to that of the subspace iteration method with shift, and the operation counts of above two methods are almost the same when a large number of eigenpairs are required. To show the effectiveness of the proposed method, two numerical examples are considered

  • PDF

자동미분을 이용한 분리시스템동시최적화기법의 개선 (Improved Concurrent Subspace Optimization Using Automatic Differentiation)

  • 이종수;박창규
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 1999년도 가을 학술발표회 논문집
    • /
    • pp.359-369
    • /
    • 1999
  • The paper describes the study of concurrent subspace optimization(CSSO) for coupled multidisciplinary design optimization (MDO) techniques in mechanical systems. This method is a solution to large scale coupled multidisciplinary system, wherein the original problem is decomposed into a set of smaller, more tractable subproblems. Key elements in CSSO are consisted of global sensitivity equation(GSE), subspace optimization (SSO), optimum sensitivity analysis(OSA), and coordination optimization problem(COP) so as to inquiry valanced design solutions finally, Automatic differentiation has an ability to provide a robust sensitivity solution, and have shown the numerical numerical effectiveness over finite difference schemes wherein the perturbed step size in design variable is required. The present paper will develop the automatic differentiation based concurrent subspace optimization(AD-CSSO) in MDO. An automatic differentiation tool in FORTRAN(ADIFOR) will be employed to evaluate sensitivities. The use of exact function derivatives in GSE, OSA and COP makes Possible to enhance the numerical accuracy during the iterative design process. The paper discusses how much influence on final optimal design compared with traditional all-in-one approach, finite difference based CSSO and AD-CSSO applying coupled design variables.

  • PDF

A Novel Subspace Tracking Algorithm and Its Application to Blind Multiuser Detection in Cellular CDMA Systems

  • Ali, Imran;Kim, Doug-Nyun;Song, Yun-Jeong;Azeemi, Naeem Zafar
    • Journal of Communications and Networks
    • /
    • 제12권3호
    • /
    • pp.216-221
    • /
    • 2010
  • In this paper, we propose and develop a new algorithm for the principle subspace tracking by orthonormalizing the eigenvectors using an approximation of Gram-Schmidt procedure. We carry out a novel mathematical derivation to show that when this approximated version of Gram-Schmidt procedure is added to a modified form of projection approximation subspace tracking deflation (PASTd) algorithm, the eigenvectors can be orthonormalized within a linear computational complexity. While the PASTd algorithm tries to extracts orthonormalized eigenvectors, the new scheme orthonormalizes the eigenvectors after their extraction, yielding much more tacking efficiency. We apply the new tracking scheme for blind adaptive multiuser detection for non-stationary cellular CDMA environment and use extensive simulation results to demonstrate the performance improvement of the proposed scheme.

비압축성 Navier-Stokes 방정식의 수렴 가속을 위한 예조건화 Krylov 부공간법과 다중 격자법의 결합 (Combination of Preconditioned Krylov Subspace Methods and Multi-grid Method for Convergence Acceleration of the incompressible Navier-Stokes Equations)

  • 맹주성;최일곤;임연우
    • 한국전산유체공학회:학술대회논문집
    • /
    • 한국전산유체공학회 1999년도 춘계 학술대회논문집
    • /
    • pp.106-112
    • /
    • 1999
  • In this article, combination of the FAS-FMG multi-grid method and the Krylov subspace method was presented in solving two dimensional driven-cavity flows. Three algorithms of the Krylov subspace method, CG, CGSTAB(Bi-CG Stabilized) and GMRES method were tested with MILU preconditioner. As a smoother of the pressure correction equation, the MILU-CG is recommended rather than MILU-GMRES(k) or MILU-CGSTAB, since the MILU-GMRES(k) preconditioner has too much computation on the coarse grid compared to the MILU-CG one. As for the momentum equation, relatively cheap smoother like SIP solver may be sufficient.

  • PDF

Parameters On-line Identification of Dual Three Phase Induction Motor by Voltage Vector Injection in Harmonic Subspace

  • Sheng, Shuang;Lu, Haifeng;Qu, Wenlong;Guo, Ruijie;Yang, Jinlei
    • Journal of international Conference on Electrical Machines and Systems
    • /
    • 제2권3호
    • /
    • pp.288-294
    • /
    • 2013
  • This paper introduces a novel method of on-line identifying the stator resistance and leakage inductance of dual three phase induction motor (DTPIM). According to the machine mathematical model, the stator resistance and leakage inductance can be estimated using the voltage and current values in harmonic subspace. Thus a method of voltage vector injection in harmonic subspace (VVIHS) is proposed, which causes currents in harmonic space. Then the errors between command and actual harmonic currents are utilized to regulate the machine parameters, including stator resistance and leakage inductance. The principle is presented and analyzed in detail. Experimental results prove the feasibility and validity of proposed method.

비압축성 Navier-Stokes 방정식에 대한 Krylov 부공간법의 적용 (Application of the Krylov Subspace Method to the Incompressible Navier-Stokes Equations)

  • 맹주성;최일곤;임연우
    • 대한기계학회논문집B
    • /
    • 제24권7호
    • /
    • pp.907-915
    • /
    • 2000
  • The preconditioned Krylov subspace methods were applied to the incompressible Navier-Stoke's equations for convergence acceleration. Three of the Krylov subspace methods combined with the five of the preconditioners were tested to solve the lid-driven cavity flow problem. The MILU preconditioned CG method showed very fast and stable convergency. The combination of GMRES/MILU-CG solver for momentum and pressure correction equations was found less dependency on the number of the grid points among them. A guide line for stopping inner iterations for each equation is offered.