• Title/Summary/Keyword: SVD

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An Implementation of Inverse Filter Using SVD for Multi-channel Sound Reproduction (SVD를 이용한 다중 채널상에서의 음재생을 위한 역변환 필터의 구현)

  • 이상권;노경래
    • The Journal of the Acoustical Society of Korea
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    • v.20 no.8
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    • pp.3-11
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    • 2001
  • This paper describes an implementation of inverse filter using SVD in order to recover the input in multi-channel system. The matrix formulation in SISO system is extended to MIMO system. In time and frequency domain we investigates the inversion of minimum phase system and non-minimum phase system. To execute an effective inversion of non-minimum phase system, SVD is introduced. First of all we computes singular values of system matrix and then investigates the phase property of system. In case of overall system is non-minimum phase, system matrix has one (or more) very small singular value (s). The very small singular value (s) carries information about phase properties of system. Using this property, approximate inverse filter of overall system is founded. The numerical simulation shows potentials in use of the inverse filter.

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Analysis of a Blogosphere using SVD (SVD를 이용한 블로그 공간 분석)

  • Kim, Ki-Nam;Kim, Sang-Wook
    • Proceedings of the Korea Information Processing Society Conference
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    • 2010.04a
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    • pp.868-869
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    • 2010
  • 본 논문은 행렬 분해 기법인 SVD를 이용하여 블로그 공간을 분석한다. 분석 결과 블로그 공간에서 커뮤니티들을 발견했고, 각 커뮤니티에 속한 영향력 있는 블로그와 포스트를 발견했다.

Noise Suppression of NMR Signal by Piecewise Polynomial Truncated Singular Value Decomposition

  • Kim, Daesung;Youngdo Won;Hoshik Won
    • Journal of the Korean Magnetic Resonance Society
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    • v.4 no.2
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    • pp.116-124
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    • 2000
  • Singular value decomposition (SVD) has been used during past few decades in the advanced NMR data processing and in many applicable areas. A new modified SVD, piecewise polynomial truncated SVD (PPTSVD) was developed far the large solvent peak suppression and noise elimination in U signal processing. PPTSVD consists of two algorithms of truncated SVD (TSVD) and L$_1$ problems. In TSVD, some unwanted large solvent peaks and noises are suppressed with a certain son threshold value while signal and noise in raw data are resolved and eliminated out in L$_1$ problem routine. The advantage of the current PPTSVD method compared to many SVD methods is to give the better S/N ratio in spectrum, and less time consuming job that can be applicable to multidimensional NMR data processing.

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A Study on the Application of SVD to an Inverse Problem in a Cantilever Beam with a Non-minimum Phase (비최소 위상을 갖는 외팔보에서 SVD를 이용한 역변환 문제에 관한 연구)

  • 이상권;노경래;박진호
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.11 no.9
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    • pp.431-438
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    • 2001
  • This paper present experimental results of source identification for non-minimum phase system. Generally, a causal linear system may be described by matrix form. The inverse problem is considered as a matrix inversion. Direct inverse method can\`t be applied for a non-minimum phase system, the reason is that the system has ill-conditioning. Therefore, in this study to execute an effective inversion, SVD inverse technique is introduced. In a Non-minimum phase system, its system matrix may be singular or near-singular and has one more very small singular values. These very small singular values have information about a phase of the system and ill-conditioning. Using this property we could solve the ill-conditioned problem of the system and then verified it for the practical system(cantilever beam). The experimental results show that SVD inverse technique works well for non-minimum phase system.

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Large Solvent and Noise Peak Suppression by Combined SVD-Harr Wavelet Transform

  • Kim, Dae-Sung;Kim, Dai-Gyoung;Lee, Yong-Woo;Won, Ho-Shik
    • Bulletin of the Korean Chemical Society
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    • v.24 no.7
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    • pp.971-974
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    • 2003
  • By utilizing singular value decomposition (SVD) and shift averaged Harr wavelet transform (WT) with a set of Daubechies wavelet coefficients (1/2, -1/2), a method that can simultaneously eliminate an unwanted large solvent peak and noise peaks from NMR data has been developed. Noise elimination was accomplished by shift-averaging the time domain NMR data after a large solvent peak was suppressed by SVD. The algorithms took advantage of the WT, giving excellent results for the noise elimination in the Gaussian type NMR spectral lines of NMR data pretreated with SVD, providing superb results in the adjustment of phase and magnitude of the spectrum. SVD and shift averaged Haar wavelet methods were quantitatively evaluated in terms of threshold values and signal to noise (S/N) ratio values.

Improved Reliable SVD-Based Watermark Scheme For Ownership Verification (소유권 확인을 위한 향상된 고신뢰성 SVD 기반 워터마킹기법)

  • Luong, Ngoc Thuy Dung;Sohn, Won
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2016.11a
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    • pp.82-84
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    • 2016
  • We propose a new reliable SVD-based watermarking scheme having high fidelity and strong robustness with no false-positive problem. Each column of the principal component of a watermark image is embedded into singular values of LL, LH, HL and HH sub-bands of cover image with different scale factors. Each scale factor is optimized by trading-off fidelity and robustness using Differential Evolution (DE) algorithm. The proposed scheme improves fidelity and robustness of existing reliable SVD based watermarking schemes without any false-positive problem. Index Terms - watermarking, reliable SVD, DWT, principal component, Differential Evolution.

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A Reliable SVD Based Watermarking Scheme Resistant to Geometric Attacks (기하학적 공격에 강한 고신뢰성 SVD 기반 워터마킹방안)

  • Dung, Luong Ngoc Thuy;Sohn, Won
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2018.11a
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    • pp.87-89
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    • 2018
  • We proposed an improved reliable SVD-based watermarking scheme resistant to geometric attacks while having high fidelity with no false-positive problem. Principal components of a watermark image are embedded into singular values of LL, LH, HL, and HH sub-bands of a transformed cover image by RDWT(redundant discrete wavelet transform) with optimal scale factors. Each scale factor is generated by trading-off fidelity and robustness using Differential Evolution (DE) algorithm. Zernike Moment (ZM) is used to estimate the geometric distortion and to correct the watermarked image before extracting watermark. The proposed scheme improves fidelity and robustness of existing reliable SVD based watermarking schemes while resisting to geometric attacks.

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An Efficient Selection Method for Document Classification Based On Singular Value Decompostion (문서분류에서 SVD(Singular Value Decompotion)기법에 기초한 효율적인 특징 선택방법 연구)

  • Li, Cheng-hua;Byun, Dong Ryul;Park, Soon Cheol
    • Proceedings of the Korea Information Processing Society Conference
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    • 2009.11a
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    • pp.321-322
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    • 2009
  • 본 논문에서는 문서분류를 위하여 SVD(Singular Value Decomposition)을 이용한 효율적인 특징 선택 방법을 제안한다. 분류기 알고리즘은 문서를 효과적으로 분류할 수 있지만 분류기에 입력되는 특징공간이 너무 크다는 단점이 있다. SVD를 이용하면 입력 데이터의 차원을 줄여줄 수 있으며 문서와 문서 사이의 관계성을 내포하는 벡터공간을 만들 수 있다. 따라서 SVD를 이용하면 문서분류의 시간과 효율을 동시에 증가시킬 수 있다. 본 논문에서는 실험을 통하여 SVD을 이용한 문서분류 시스템이 입력데이터에 대한 차원을 감소시키면서 훌륭한 분류 결과를 얻을 수 있음을 보여준다.

A study on the global optimization in the design of a camera lens-system (사진 렌즈계 설계에서 전역 최적화에 관한 연구)

  • Jung, Jung-Bok;Jang, Jun-Kyu;Choi, Woon-Sang;Jung, Su-Ja
    • Journal of Korean Ophthalmic Optics Society
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    • v.6 no.2
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    • pp.121-127
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    • 2001
  • While SVD and Gaussian elimination method were applied to the additive damped least squares(DLS), the convergence and the stability of the optimization process were examined in a triplet-type camera lens-system where the condition number is well conditioned. DLS with SVD method generated a suitable merit function but this merit function may be trapped in a local minimum by the nonlinearity of error function. Therefore, the least camera lens-system was further designed by the global optimization method is grid method, and this method is adopted to get merit function that convergent to global minimum without local minimum trapping.

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Pseudo Jacket Matrix and Its MIMO SVD Channel (Pseudo Jacket 행렬을 이용한 MIMO SVD Channel)

  • Yang, Jae-Seung;Kim, Jeong-Su;Lee, Moon-Ho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.5
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    • pp.39-49
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    • 2015
  • Some characters and construction theorems of Pseudo Jacket Matrix which is generalized from Jacket Matrix introduced by Jacket Matrices: Construction and Its Application for Fast Cooperative Wireless signal Processing[27] was announced. In this paper, we proposed some examples of Pseudo inverse Jacket matrix, such as $2{\times}4$, $3{\times}6$ non-square matrix for the MIMO channel. Furthermore we derived MIMO singular value decomposition (SVD) pseudo inverse channel and developed application to utilize SVD based on channel estimation of partitioned antenna arrays. This can be also used in MIMO channel and eigen value decomposition (EVD).