• Title, Summary, Keyword: H-matrix

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A Design Method of Multi-Rate Low Density Parity Check Code (다수의 코드율이 가능한 저밀도 패러티 체크 코드의 설계 방법)

  • Hwang, Sung-Hee;Kim, Jin-Han;Park, Hyun-Soo
    • Transactions of the Society of Information Storage Systems
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    • v.3 no.3
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    • pp.126-128
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    • 2007
  • 일반적으로 주어진 하나의 H matrix 로 다수의 코드율을 가지는 코드화가 가능하다. 하지만 Low Density Parity Check(LDPC) 코드의 H matrix는 H matrix 내의 1의 개수와 위치에 따라 그 성능이 달라짐으로 해서 하나의 H matrix로 다수의 코드율을 대응하기 위한 설계 방법이 요구된다. H matrix 의 성능은 일반적으로 girth나 minimum distance에 의해 좌우되고 H matrix의 1의 위치에 따라 달라진다. 본 논문에서는 H matrix의 girth 와 minimum distance에 입각한 다수 개의 코드율이 대응 가능한 LDPC code의 H matrix 설계 방법을 제시하고자 한다. 이렇게 함으로써 하나의 H matrix로 다수의 코드율에 따른 각각의 성능을 일정 수준 이상 유지하는 multi-rate LDPC code가 가능하다.

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Fixed-Order $H_{\infty}$ Controller Design for Descriptor Systems

  • Zhai, Guisheng;Yoshida, Masaharu;Koyama, Naoki
    • 제어로봇시스템학회:학술대회논문집
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    • pp.898-902
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    • 2003
  • For linear descriptor systems, we consider the $H_{INFTY}$ controller design problem via output feedback. Both static output feedback and dynamic one are discussed. First, in the case of static output feedback, we reduce our control problem to solving a bilinear matrix inequality (BMI) with respect to the controller coefficient matrix, a Lyapunov matrix and a matrix related to the descriptor matrix. Under a matching condition between the descriptor matrix and the measured output matrix (or the control input matrix), we propose setting the Lyapunov matrix in the BMI as being block diagonal appropriately so that the BMI is reduced to LMIs. For fixed-order dynamic $H_{INFTY}$ output feedback, we formulate the control problem equivalently as the one of static output feedback design, and thus the same approach can be applied.

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SEVERAL NEW PRACTICAL CRITERIA FOR NONSINGULAR H-MATRICES

  • Mo, Hongmin
    • Journal of applied mathematics & informatics
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    • v.28 no.3_4
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    • pp.987-992
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    • 2010
  • H-matrix is a special class of matrices with wide applications in engineering and scientific computation, how to judge if a given matrix is an H-matrix is very important, especially for large scale matrices. In this paper, we obtain several new practical criteria for judging nonsingular H-matrices by using the partitioning technique and Schur complement of matrices. Their effectiveness is illustrated by numerical examples.

New Robust $H_{\infty}$ Performance Condition for Uncertain Discrete-Time Systems

  • Zhai, Guisheng;Lin, Hai;Kim, Young-Bok
    • 제어로봇시스템학회:학술대회논문집
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    • pp.322-326
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    • 2003
  • In this paper, we establish a new robust $H_{\infty}$ performance condition for uncertain discrete-time systems with convex polytopic uncertainties. We express the condition as a set of linear matrix inequalities (LMIs), which are used to check stability and $H_{\infty}$ disturbance attenuation level by a parameter-dependent Lyapunov matrix. We show that the new condition provides less conservative result than the existing ones which use single Lyapunov matrix. We also show that the robust $H_{\infty}$ state feedback design problem for such uncertain discrete-time systems can be easily dealt with using the approach. The key point in this paper is to propose a kind of decoupling between the Lyapunov matrix and the system matrices in the parameter-dependent matrix inequality by introducing one new matrix variable.

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Yield enhancement of matrix precursor in short carbon fiber reinforced randomly oriented carbon/carbon composite

  • Raunija, Thakur Sudesh Kumar;Sharma, Sharad Chandra;Verma, Anil
    • Carbon letters
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    • v.19
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    • pp.57-65
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    • 2016
  • Isroaniso matrix precursor synthesized from commercially available petroleum pitch was stabilized in air. The influence of oxygen mass gain during stabilization on the yield of matrix precursor was studied. Additionally, the influence of pressure on the yield of the stabilized matrix precursor in a real system was studied. The fourier transform infrared spectrometry (FTIR), thermogravimetric analysis (TGA), yield, yield rate, and yield impact were used to check the effect of stabilization and pressure on the yield of the matrix precursor and the end properties of the composite thereafter. The results showed that the yield increased with stabilization duration up to 20 h whereas it decreased for stabilization duration beyond 20 h. Further results showed that the stabilized matrix precursor for a duration of 5 h could withstand almost two-fold greater hot-pressing pressure without resulting in exudation as compared to that of a 1 h stabilized matrix precursor. The enhanced hot-pressing pressure significantly improved the yield of the matrix precursor. As a consequence, the densification and mechanical properties were increased significantly. Further, the matrix precursor stabilized for a duration of 20 h or more failed to provide proper and uniform binding of the reinforcement.

Periodontal tissue engineering by hPDLF seeding on scaffold (Scaffold상에 식립한 사람치주인대섬유모세포를 통한 치주조직공학)

  • Kim, Seong Sin;Kim, Byung-Ock;Park, Joo-Cheol;Jang, Hyun-Seon
    • Journal of Periodontal and Implant Science
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    • v.36 no.3
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    • pp.757-765
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    • 2006
  • Human periodontal ligament fibroblasts (hPDLF) are very important for curing the periodontal tissue because they can be differentiated into various cells. A tissue engineering approach using a cell-scaffold is essential for comprehending today's periodontal tissue regeneration procedure. This study examined the possibility of using an acellular dermal matrix as a scaffold for human periodontalligament fibroblast (hPDLF). The hPDLF was isolated from the middle third of the root of periodontally healthy teeth extracted for orthodontic reasons. The cells were cultured in a medium containing Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum at $37^{\circ}C$ in humidified air with 5% $CO_2$. The acellular dermal matrix(ADM) was provided by the US tissue banks(USA). Second passage cells were used in this study. The hPDLF cells were cultured with the acellular dermal matrix for 2 days, and the dermal matrix cultured by the hPDLF was transferred to a new petri dish and used as the experimental group. The control group was cultured without the acellular dermal matrix, The control and experimental cells were cultured for six weeks. The hPDLF cultured on the acellular dermal matrix was observed by Transmission Electron microscopy (TEM). Electron micrography shows that the hPDLF was proliferated on the acellular dermal matrix. This study suggests that the acellular dermal matrix can be used as a scaffold for hPDLF.

A method for intra-prediction in the Integer DCT domain of H.264 (H.264의 integer DCT 영역에서의 Intra-prediction 기법)

  • Ahn, Hyeong-Jin;Oh, Hyung-Suk;Kim, Won-Ha
    • Proceedings of the KIEE Conference
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    • pp.91-92
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    • 2008
  • 본 논문에서는 기존의 H.264/AVC의 spatial 영역에서 Intra prediction 기법과 달리 H.264/AVC에서 사용하는 Integer DCT 영역에서 Intra prediction 기법을 제안한다. 이를 위하여 Integer DCT 영역에서 Intra prediction을 수행하는 모든 과정을 matrix multiplication으로 표현하여 Intra prediction을 수행하는 matrix를 유도한다. Intra prediction을 수행하는 matrix를 각 모드에 알맞게 설계하고, 이 matrix를 Integer DCT 영역에서 사용할 수 있도록 orthogonal한 Integer matrix를 설계한다. 실험을 통하여 제안한 Integer DCT 영역에서 Intra prediction 기법이 기존의 H.264/AVC의 spatial 영역에서 intra prediction 기법과 성능이 동일하면서 어떻게 matrix multiplication에 연산들을 포함시켜서 단순화 할 수 있는지를 보여주겠다. 또한 H.264/AVC에서 제공하는 intra prediction 각 모드에 대해 계산상 복잡도를 분석하였다.

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CONVERGENCE OF THE GENERALIZED MULTISPLITTING AND TWO-STAGE MULTISPLITTING METHODS

  • Oh, Se-Young;Yun, Jae-Heon;Han, Yu-Du
    • Journal of applied mathematics & informatics
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    • v.26 no.3_4
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    • pp.501-510
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    • 2008
  • In this paper, we first provide a convergence result of the generalized two-stage splitting method for solving a linear system whose coefficient matrix is an H-matrix, and then we provide convergence results of the generalized multisplitting and two-stage multisplitting methods for both a monotone matrix and an H-matrix.

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BLOCK INCOMPLETE FACTORIZATION PRECONDITIONERS FOR A SYMMETRIC H-MATRIX

  • Yun, Jae-Heon;Kim, Sang-Wook
    • Bulletin of the Korean Mathematical Society
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    • v.37 no.3
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    • pp.551-568
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    • 2000
  • We propose new parallelizable block incomplete factorization preconditioners for a symmetric block-tridiagonal H-matrix. Theoretical properties of these block preconditioners are compared with those of block incomplete factorization preconditioners for the corresponding comparison matrix. Numerical results of the preconditioned CG(PCG) method using these block preconditioners are compared with those of PCG method using a standard incomplete factorization preconditioner to see the effectiveness of the block incomplete factorization preconditioners.

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Matrix Development in Cast Iron by Addition of Mischmetal Hydrides (주철(鑄鐵)의 기지조직(基地組織)에 미치는 Mischmetal Hydride의 첨가효과(添加效果))

  • Choi, Dap-Chun;Jin, Young-Chul
    • Journal of Korea Foundry Society
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    • v.8 no.4
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    • pp.422-428
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    • 1988
  • In this study we have investigated the effects of Mm, MmH and $MmH_2$ on the matrix development in cast iron, The conclusive summary is as follows: The spheroidal graphite was observed when 0.5wt.% or more of mischmetal was added and the matrix was of ledeburite structure, but bull's eye structure was not observed. On the other hand, the bull's eye structure was observed when 0.25wt.% of MmH, or 0.25wt.% to 0.5wt.% of $MmH_2$ was added. Above limit of the additives, the matrix changed into ledeburite structure. As the hydrogen content of mischmetal compound increased from MmH, the range of additives to obtain bull's eye structure expanded. This reveals the significant effect of mischmetal hydride on matrix development in cast iron and the possibility of practical use of the additives.

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