• Title/Summary/Keyword: Subspace

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Subspace-Based Adaptive Beamforming with Off-Diagonal Elements (비 대각요소를 이용한 부공간에서의 적응 빔 형성 기법)

  • Choi Yang-Ho;Eom Jae-Hyuck
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.1A
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    • pp.84-92
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    • 2004
  • Eigenstructure-based adaptive beamfoming has advantages of fast convergence and the insentivity to errors in the arrival angle of the desired signal. Eigen-decomposing the sample matrix to extract a basis for the Sl (signal plus interference) subspace, however, is very computationally expensive. In this paper, we present a simple subspace based beamforming which utilizes off-diagonal elements of the sample matrix to estimate the Sl subspace. The outputs of overlapped subarrays are combined to produce the final adaptive output, which improves SINR (signal-to-interference-plus-noise ratio) comapred to exploiting a single subarray. The proposed adaptive beamformer, which employs an efficient angle estimation is very roubust to errors in both the arrival angles and the number of the incident signals, while the eigenstructure-based beamforer suffers from severe performance degradation.

ON INTUITIONISTIC FUZZY SUBSPACES

  • Ramadan, Ahmed Abd El-Kader;El-Latif, Ahmed Aref Abd
    • Communications of the Korean Mathematical Society
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    • v.24 no.3
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    • pp.433-450
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    • 2009
  • We introduce a new concept of intuitionistic fuzzy topological subspace, which coincides with the usual concept of intuitionistic fuzzy topological subspace due to Samanta and Mondal [18] in the case that $\mu=X_A$ for A $\subseteq$ X. Also, we introduce and study some concepts such as continuity, separation axioms, compactness and connectedness in this sense.

Investigating SIR, DOC and SAVE for the Polychotomous Response

  • Lee, Hak-Bae;Lee, Hee-Min
    • Communications for Statistical Applications and Methods
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    • v.19 no.3
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    • pp.501-506
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    • 2012
  • This paper investigates the central subspace related with SIR, DOC and SAVE when the response has more than two values. The subspaces constructed by SIR, DOC and SAVE are investigated and compared. The SAVE paradigm is the most comprehensive. In addition, the SAVE coincides with the central subspace when the conditional distribution of predictors given the response is normally distributed.

Extended PASTd (Projection Approximation Subspace Tracking with Deflation) Algorithm for time-varying DOA estimation (시변 방위 추정을 위한 Extended PASTd (Projection Approximation Subspace Tracking with Deflation) 알고리즘)

  • Lim Jun-Seok;Lee Jong-Myong
    • Proceedings of the Acoustical Society of Korea Conference
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    • spring
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    • pp.189-192
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    • 2000
  • 본 논문은 Nonstationary 환경에서 동작하는 소나의 DOA추정의 정확도를 높이기 위하여 가변 망각인자를 도입한 새로운 Extended PASTd (Extended Projection Approximation of Subspace Tracking with deflation) 을 제안하고 기존 알고리즘과 비교함으로써 새로운 알고리즘의 향상된 성능을 보인다.

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Implementation of Improved Functional Router Using Embedded Linux System (Subspace projection과 SCORE algorithm을 이용한 두 가지 전파방해 대응기술의 성능비교)

  • Han, Sang-Yoon;Shin, Jung-Hwan;Heo, Jun
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.79-80
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    • 2006
  • In this paper, we compare two different anti-jamming schemes, Subspace projection and SCORE algorithm. For multipath cancelation, nulling technique is applied to both anti-jamming schemes. It is noted that SCORE algorithm is more robust to the multipath interference. It is also noted that Subspace projection scheme requires nulling technique for multipath mitigation.

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Accelerated Subspace Iteration Method for Computing Natural Frequencies and Mode Shapes of Structures (구조물의 고유진동수 및 모드형상의 계산을 위한 가속화된 부분공간반복법)

  • Kim, Byoung-Wan;Kim, Chun-Ho;Lee, In-Won
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.503-508
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    • 2003
  • This paper proposes modified subspace iteration method for efficient frequency analysis of structures. Proposed method uses accelerated Lanczos vectors as starting vectors in order to reduce the number of iterations in the subspace iteration method. Proposed method has better computing efficiency than the conventional method when the number of desired frequencies is relatively small. The efficiency of proposed method is verified through numerical examples.

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A MIXED METHOD OF SUBSPACE ITERATION FOR DIRICHLET EIGENVALUE PROBLEMS

  • Lee, Gyou-Bong;Ha, Sung-Nam;Hong, Bum-Il
    • Journal of applied mathematics & informatics
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    • v.4 no.1
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    • pp.243-248
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    • 1997
  • A full multigrid scheme was used in computing some eigenvalues of the Laplace eigenvalues problem with the Dirichlet bound-ary condition. We get a system of algebraic equations with an aid of finite difference method and apply subspace iteration method to the system to compute first some eigenvalues. The result shows that this is very effective in calculating some eigenvalues of this problem.

The Image of Derivations on Banach Algebras of Differential Functions

  • Park, Dal-Won
    • Journal of the Chungcheong Mathematical Society
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    • v.2 no.1
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    • pp.81-90
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    • 1989
  • Let $D:C^n(I){\longrightarrow}M$ be a derivation from the Banach algebra of n times continuously differentiable functions on an interval I into a Banach $C^n(I)$-module M. If D is continuous and D(z) is contained in the k-differential subspace, the image of D is contained in the k-differential subspace. The question of when the image of a derivation is contained in the k-differential subspace is discussed.

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Accelerated Starting Vectors for Analysis of Natural Modes of Structures (구조물의 고유모드 해석을 위한 가속화된 초기벡터 구성기법)

  • 김병완;정형조;이인원
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.784-787
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    • 2004
  • Modified version of subspace iteration method using accelerated starting vectors is proposed to efficiently calculate free vibration modes of structures. Proposed method employs accelerated Lanczos starting vectors that can reduce the number of iterations in the subspace iteration method. Proposed method is more efficient than the conventional method when the number of required modes is relatively small. To verify the efficiency of proposed method, two numerical examples are presented.

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A Study on the System Identification of Cold Tandem Mills using the Subspace Method (부분 공간법을 이용한 연속 냉간 압연기의 시스템 규명에 관한 연구)

  • 장유신;김인수;이만형
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.299-303
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    • 1995
  • This paper charcterizes dynamics of cold tandem minns, and constructs it state-space model of which are linear time invariant, using subspace method. Step responses particularly show the influence on mass transfer delay. Input-output data set are obtained form nonlinear differential equations including mass transfer delay and nonlinearity. It is shown that the identified state-apace model well approximates the original systems dynamics.

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