• 제목/요약/키워드: subspace method

검색결과 333건 처리시간 0.027초

직교 투사를 이용한 최적 레이다 신호 검출기 (An Optimum Radar Signal Detector using Orthogonal Projection)

  • 김영훈;김기만;이종길;박영찬;곽영길;윤대희
    • 한국통신학회논문지
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    • 제19권7호
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    • pp.1407-1413
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    • 1994
  • 레이다에서 정확한 표적 정보를 얻기 위해서는 우선 클러터나 간섭 신호를 효율적으로 제거하고 표적을 검출하여야 한다. 본 논문에서는 신호를 제한 조건에 의해 구별되는 직교 부공간으로 투사함으로써 최분산 기분을 갖는 최적 검출기를 제한 조건을 갖지 않는 검출기로 변형하였다. 제안된 방법은 기존의 최적검출 알고리듬과 등가이며, 역행렬을 구하지 않고서도 빠른 수렴속도를 얻기위한 Gram-Schmidt 적교화가 가능한 구조를 가지게 된다. 모의 실험을 통해 제안된 검출기가 공간과 주파수 영역에서 적응적으로 잘 동작하고 있음을 보였다.

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텐서의 비음수 Tucker 분해 (Nonnegative Tucker Decomposition)

  • 김용덕;최승진
    • 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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    • 제14권3호
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    • pp.296-300
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    • 2008
  • 최근에 개발된 Nonnegative tensor factorization(NTF)는 비음수 행렬 분해(NMF)의 multiway(multilinear) 확장형이다. NTF는 CANDECOMP/PARAFAC 모델에 비음수 제약을 가한 모델이다. 본 논문에서는 Tucker 모델에 비음수 제약을 가한 nonnegative Tucker decomposition(NTD)라는 새로운 텐서 분해 모델을 제안한다. 제안된 NTD 모델을 least squares, I-divergence, $\alpha$-divergence를 이용한 여러 목적함수에 대하여 fitting하는 multiplicative update rule을 유도하였다.

HDD 용 구동 및 현가 장치의 축소 진동 모델의 생성 및 해석 (Generation and Analysis of Reduced Vibration Models for a HDD Actuator and Suspension System)

  • 한정삼
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2006년도 춘계학술대회 논문집
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    • pp.121-122
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    • 2006
  • In the case of mechanical control systems, it is highly useful to be able to provide a compact model of the mechanical system to control engineers using the smallest number of variables, while still providing an accurate model. The reduced mechanical model can then be inserted into the complete mechanical control system models and used for system-level dynamic simulation. In this paper, a moment-matching based model order reduction (MOR) which reduces the number of degrees of freedom of an original finite element model via the Arnoldi process is considered to study the dynamic responses of a HDD actuator and suspension system.

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축소된 유한요소모델을 이용한 하드디스크 구동부의 고유치 및 주파수응답 해석 (Eigenvalue and Frequency Response Analyses of a Hard Disk Drive Actuator Using Reduced Finite Element Models)

  • 한정삼
    • 대한기계학회논문집A
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    • 제31권5호
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    • pp.541-549
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    • 2007
  • In the case of control for mechanical systems, it is highly useful to be able to provide a compact model of the mechanical system to control engineers using the smallest number of state variables, while still providing an accurate model. The reduced mechanical model can then be inserted into the complete system models and used for extended system-level dynamic simulation. In this paper, moment-matching based model order reductions (MOR) using Krylov subspaces, which reduce the number of degrees of freedom of an original finite element model via the Arnoldi process, are presented to study the eigenvalue and frequency response problems of a HDD actuator and suspension system.

A New Compressive Feedback Scheme Based on Distributed Compressed Sensing for Time-Correlated MIMO Channel

  • Li, Yongjie;Song, Rongfang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제6권2호
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    • pp.580-592
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    • 2012
  • In this paper, a new compressive feedback (CF) scheme based on distributed compressed sensing (DCS) for time-corrected MIMO channel is proposed. First, the channel state information (CSI) is approximated by using a subspace matrix, then, the approximated CSI is compressed using a compressive matrix. At the base station, the approximated CSI can be robust recovered with simultaneous orthogonal matching pursuit (SOMP) algorithm by using forgone CSIs. Simulation results show our proposed DCS-CF method can improve the reliability of system without creating a large performance loss.

A Systematic Design of Automatic Fuzzy Rule Generation for Dynamic System

  • Kang, Hoon;Kim, Young-Ho;Jeon, Hong-Tae
    • 한국지능시스템학회논문지
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    • 제2권3호
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    • pp.29-39
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    • 1992
  • We investigate a systematic design procedure of automatic rule generation of fuzzy logic based controllers for highly nonlinear dynamic systems such as an engine dynamic modle. By "automatic rule generation" we mean autonomous clustering or collection of such meaningful transitional relations from one conditional subspace to another. During the design procedure, we also consider optimaly control strategies such as minimum squared error, near minimum time, minimum energy or combined performance critiera. Fuzzy feedback control systems designed by our method have the properties of closed-loop stability, robustness under parameter variabitions, and a certain degree of optimality. Most of all, the main advantage of the proposed approach is that reliability can be potentially increased even if a large grain of uncertainty is involved within the control system under consideration. A numerical example is shown in which we apply our strategic fuzzy controller dwsign to a highly nonlinear model of engine idling speed control.d control.

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Appearance-based Robot Visual Servo via a Wavelet Neural Network

  • Zhao, Qingjie;Sun, Zengqi;Sun, Fuchun;Zhu, Jihong
    • International Journal of Control, Automation, and Systems
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    • 제6권4호
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    • pp.607-612
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    • 2008
  • This paper proposes a robot visual servo approach based on image appearance and a wavelet function neural network. The inputs of the wavelet neural network are changes of image features or the elements of image appearance vector, and the outputs are changes of robot joint angles. Image appearance vector is calculated by using eigen subspace transform algorithm. The proposed approach does not need a priori knowledge of the robot kinematics, hand-eye geometry and camera models. The experiment results on a real robot system show that the proposed method is practical and simple.

Multi-Label Classification Approach to Location Prediction

  • Lee, Min Sung
    • 한국컴퓨터정보학회논문지
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    • 제22권10호
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    • pp.121-128
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    • 2017
  • In this paper, we propose a multi-label classification method in which multi-label classification estimation techniques are applied to resolving location prediction problem. Most of previous studies related to location prediction have focused on the use of single-label classification by using contextual information such as user's movement paths, demographic information, etc. However, in this paper, we focused on the case where users are free to visit multiple locations, forcing decision-makers to use multi-labeled dataset. By using 2373 contextual dataset which was compiled from college students, we have obtained the best results with classifiers such as bagging, random subspace, and decision tree with the multi-label classification estimation methods like binary relevance(BR), binary pairwise classification (PW).

선형 다변수 입출력 시스템에서 좌 고유벡터의 방향 지정 (Direction Assignment of Left Eigenvector in Linear MIMO System)

  • 김성현;양현석
    • 제어로봇시스템학회논문지
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    • 제14권3호
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    • pp.226-231
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    • 2008
  • In this paper, we propose novel eigenstructure assignment method in full-state feedback for linear time-invariant MIMO system such that directions of some left eigenvectors are exactly assigned to the desired directions. It is required to consider the direction of left eigenvector in designing eigenstructure of closed-loop system, because the direction of left eigenvector has influence over excitation by associated input variables in time-domain response. Exact direction of a left eigenvector can be achieved by assigning proper right eigenvector set satisfying the conditions of the presented theorem based on Moore's theorem and the orthogonality of left and right eigenvector. The right eigenvector should reside in the subspace given by the desired eigenvalue, which restrict a number of designable left eigenvector. For the two cases in which desired eigenvalues are all real and contain complex number, design freedom of designable left eigenvector are given.

Identification of the Relationship between Operating Conditions and Polymer Qualities in a Continuous Polymerization Reactor

  • Jeong, Boong-Goon;Yoo, Kee-Youn;Rhee, Hyun-Ku
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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    • pp.501-506
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    • 1998
  • A mathematical model is developed to describe the relationship between the manipulated variables (e.g. jacket inlet temperature and feed flow rate) and the important qualities (e.g conversion and weight average molecular weight (Mw)) in a continuous polymerization reactor. The subspace-based identification method for Wiener model is used to retrieve from the discrete sample data the accurate information about both the structure and initial parameter estimates for iterative parameter optimization methods. The comparison of the output of the identified Wiener model with the outputs of a non-linear plant model shows a fairly satisfactory degree of accordance.

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