• 제목/요약/키워드: Gram-Schmidt

검색결과 71건 처리시간 0.033초

선형 제한 조건을 갖는 적응 Escalator 빔 형성기 (An Adaptive Escalator Beamformer with Linear Constraints)

  • 김희창;김기만;박상택;차일환;윤대희
    • 전자공학회논문지B
    • /
    • 제30B권8호
    • /
    • pp.16-22
    • /
    • 1993
  • As a method of separating the signal arriving from a desired direction in the presence of noise and interfering signals, a linearly constrained adaptive beamformer based on the escalator (Gram-Schmidt) structure is presented. The weights are chosen to minimize local output power subject to the response constraint. The performances of the proposed escalator adaptive beamformer are compared with those of cascade adaptive beamformer via computer simulations.

  • PDF

On the Fitting ANOVA Models to Unbalanced Data

  • Jong-Tae Park;Jae-Heon Lee;Byung-Chun Kim
    • Communications for Statistical Applications and Methods
    • /
    • 제2권1호
    • /
    • pp.48-54
    • /
    • 1995
  • A direct method for fitting analysis-of-variance models to unbalanced data is presented. This method exploits sparsity and rank deficiency of the matrix and is based on Gram-Schmidt orthogonalization of a set of sparse columns of the model matrix. The computational algorithm of the sum of squares for testing estmable hyphotheses is given.

  • PDF

적응 Whitening 필터를 이용한 최적 레이다 신호처리기의 구현 (Implementation of Optimum Radar Signal Processor Using Adaptive Whitening Filter)

  • 김기만
    • 한국음향학회:학술대회논문집
    • /
    • 한국음향학회 1991년도 학술발표회 논문집
    • /
    • pp.157-162
    • /
    • 1991
  • 본 연구에서는 적응 whitening 필터를 이용하여 최적 레이다 신호처리기를 구현하였다. 사용된 필터는 Gram-Schmidt와 lattice 구조를 가지며, 이들을 이용하여 레이다 clutter를 제거하고, 프로세서 특성을 원하는 표적신호에 일치시킨다. 또한 필터 계수들을 변화하는 레이다 환경에 따라 조정하기 위하여 여러 가지 적응 알고리듬을 적용하였다. 실험결과 구현된 시스템은 빠른 수렴 특성을 갖고 있으며, 역행렬 연산이 필요없기 때문에 향상 안정된 특성을 보임을 알 수 있다.

  • PDF

입사각 추정을 위한 고유 부공간 적응 추정 알고리듬 (Adaptive Eigensubspace Estimation Algorithm for Direction Finding Problem)

  • 성하종;박영철;이충용;윤대희
    • 한국음향학회지
    • /
    • 제17권4호
    • /
    • pp.42-50
    • /
    • 1998
  • 본 논문에서는 Gram-Schmidt 구조와 Inverse Power Method를 이용한 고유 부공간 추정 방법을 제안하고 입사각을 추정하는 문제에 적용하여 성능을 평가하였다. 그리고, 어레 이 센서들이 가운데를 중심으로 대칭으로 배열되어 있을 때, 전후방 GS 필터를 이용한 향 상된 고유 부공간 방법을 제안하였다. 그리고, 제안한 방법들을 제한조건을 갖는 gradient search 방법과 비교하였다.

  • PDF

A Least Squares Approach to Escalator Algorithms for Adaptive Filtering

  • Kim, Nam-Yong
    • ETRI Journal
    • /
    • 제28권2호
    • /
    • pp.155-161
    • /
    • 2006
  • In this paper, we introduce an escalator (ESC) algorithm based on the least squares (LS) criterion. The proposed algorithm is relatively insensitive to the eigenvalue spread ratio (ESR) of an input signal and has a faster convergence speed than the conventional ESC algorithms. This algorithm exploits the fast adaptation ability of least squares methods and the orthogonalization property of the ESC structure. From the simulation results, the proposed algorithm shows superior convergence performance.

  • PDF

적응 쌍선형 격자필터(I) - 쌍선형 격자구조 (Adaptive Bilinear Lattice Filter(I)-Bilinear Lattice Structure)

  • Heung Ki Baik
    • 전자공학회논문지B
    • /
    • 제29B권1호
    • /
    • pp.26-33
    • /
    • 1992
  • This paper presents lattice structure of bilinear filter and the conversion equations from lattice parameters to direct-form parameters. Billnear models are attractive for adaptive filtering applications because they can approximate a large class of nonlinear systems adequately, and usually with considerable parsimony in the number of coefficients required. The lattice filter formulation transforms the nonlinear filtering problem into an equivalent multichannel linear filtering problem and then uses multichannel lattice filtering algorithms to solve the nonlinear filtering problem. The lattice filters perform a Gram-Schmidt orthogonalization of the input data and have very good easily extended to more general nonlinear output feedback structures.

  • PDF

독립성분해석 기법과 그람-슈미트 방법을 이용한 영상분리방법 (Image classification method using Independent Component Analysis and Gram-Schmidt method)

  • 홍준식;유정웅
    • 한국정보과학회:학술대회논문집
    • /
    • 한국정보과학회 2001년도 봄 학술발표논문집 Vol.28 No.1 (A)
    • /
    • pp.505-507
    • /
    • 2001
  • 본 논문에서는 그람-슈미트 방법 및 독립 성분 해석(Independent Component Analysis, ICA)기법을 이용한 영상분리방법을 제안한다. 이 제안된 방법은 전처리 없이 ICA나 주성분 해석(Principal Component Analysis, PCA)을 이용한 것에 비해 개선된 영상을 보여준다. 이는 원래의 ICA 모델에 대하여 동일한 조건으로 일반화하여 그람-슈미트의 독립된 성분들이 ICA 모델에 충분히 동일하다는 것을 보여준다.

FFT와 그람-슈미트 정규직교화를 이용한 워터마킹 (Watermarking using Fast Fourier Transform and Gram-Schmidt Orthogonalization)

  • 차선희;윤희주;차의영
    • 한국정보과학회:학술대회논문집
    • /
    • 한국정보과학회 2005년도 한국컴퓨터종합학술대회 논문집 Vol.32 No.1 (B)
    • /
    • pp.808-810
    • /
    • 2005
  • 분 논문에서는 워터마크가 삽입된 영상의 비가시성과 강인성을 보장하기 위하여 주파수 영역 기반인 FFT(Fast Fourier Transform)을 이용하였다. 그리고 영상에 삽입된 워터마크를 정확하게 추출하기 위하여 워터마크에 삽입하는 키 사이의 직교성을 유지할 수 있는 그람-슈미트 정규직교화를 이용하였다. 실험을 통해 살펴본 결과 영상의 특징에 관계없이 랜덤계열에 민감한 워터마크를 추출할 수 있는 정확성 및 신뢰성을 가짐을 알 수 있었다.

  • PDF

Synthesis and Antimicrobial Activity of Novel Tetrahydrobenzothienopyrimidines

  • Amal Abdel Haleem Mohamed Eissa;Ashraf Ahmed Moneer
    • Archives of Pharmacal Research
    • /
    • 제27권9호
    • /
    • pp.885-892
    • /
    • 2004
  • Due to the rapidly growing number of resistant strains of bacteria, the search for antibacterial agents with new modes of action will always remain an important and challenging task. Thus, the reaction of 2-substituted or. unsubstituted-4-(4-acetylanilino)-5,6,7,8-terahydrobenzo[b] thieno[2,3-d]pyrimidine derivatives 1-3 with the hydrazine derivatives, semi and / or thiosemi-carbazides, provided the corresponding hydrazones 4-6 and semi and/or thiosemicarbazones 7-9. Claisen-Schmidt condensation of compounds 1 or 2 with the appropriate aldehyde yielded the chalcones 10, 11 which, when treated with hydroxylamine hydrochloride gave rise to the isoxazoline-containing compounds 12, 13. Furthermore, reacting the respective chalcones 10, 11 with different hydrazines, urea and/or thiourea, furnished compounds 14, 15, 16, and 17 respectively. Representative compounds were tested for their antimicrobial activity against Candida Albicans and certain gram-positive and gram-negative bacteria. Their MICs were then determined. Compound 15e, showed a broad spectrum of activity while most of the other com-pounds showed varying antimicrobial activity.

'세신불가전(細辛不過錢)'에 관한 연구 (A study of 'Asari Herba should not exceed Jeon(錢, Qian, 3.0 gram)')

  • 박필상;강옥화;이고훈;박신영;성만준;권동렬
    • 대한본초학회지
    • /
    • 제22권1호
    • /
    • pp.49-52
    • /
    • 2007
  • Objectives: Asari Herba comes from the dried perennial herbaceous plant, Asarum sieboldii $M_{IQ}$., A. heterotropides $F_R$. SCHMIDT var. mandshuricum($M_{AXIM}$) $K_{ITAG}$. and A sieboldii $M_{IQ}$ var. seoulense $N_{AKAI}$., family Aristolochiaceae. This medicine is pungent in flavor(味辛), warm in nature(性溫), mildly toxic and affects the lung, kidney, and heart meridians. It is able to repel wind dispel cold(祛風散寒), remove the obstruction of the nose(宣通鼻竅), relieve pain(止痛) and warm the lungs to remove the retention of fluids(溫肺化飮). In a clinic it is prescribed for exterior syndrome of wine-cold type(風寒表證) manifested as headache and general pain. It is indicated for headaches, toothaches, bisyndrome of wind-cold-dampness type(風寒濕痺), etc. For many generations medical books have warned doctors that the dosage of Asari Herba should not be excessive because the pungent flavor has the effect of dispersing exopathogens from superficies of the body. The principle, 'Asari Herba should not exceed Jeon(錢, Qian, 3.0 gram)' is still considered to be relevant. Methods : Extensive research of several ancient medical texts has lead to the following conclusion. Results : The statement 'Asari Herba should not exceed Jeon' is a dosage which is used to prepare single recipe and powder. Conclusion : The definition of Jeon is not 1 Jeon(3.0 gram), but 1 Jeonbi(錢匕, Qianbi, 1.0 gram), moreover, the usage, collection. and refinement process are not in accordance with the contents of the ancient medical texts. A deeper study of Asari Herba's dosage in the future is expected to have interesting results.

  • PDF