• Title/Summary/Keyword: H-matrix

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Explicit matrix elements for Raman scattering blueward of H gamma

  • Lee, Hee-Won
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.50.2-50.2
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    • 2010
  • We present the explicit expressions for the matrix elements associated with the interaction of photons with atomic hydrogen. These expressions are applied to compute the scattering cross section for the Raman scattering operating blueward of Lyman epsilon and H gamma. A brief discussion that re relevant to some symbiotic stars and young planetary nebulae is also presented.

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Efficient Use of Unused Spare Columns for Reducing Memory Miscorrections

  • Jung, Ji-Hun;Ishaq, Umair;Song, Jae-Hoon;Park, Sung-Ju
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.12 no.3
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    • pp.331-340
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    • 2012
  • In the deep sub-micron ICs, growing amounts of on-die memory and scaling effects make embedded memories increasingly vulnerable to reliability and yield problems. Spare columns are often included in memories to repair defective cells or bit lines during production test. In many cases, the repair process will not use all spare columns. Schemes have been proposed to exploit these unused spare columns to store additional check bits which can be used to reduce the miscorrection probability for triple errors in single error correction-double error detection (SEC-DED). These additional check bits increase the dimensions of the parity check matrix (H-matrix) requiring extra area overhead. A method is proposed in this paper to efficiently fill the extra rows of the H-matrix on the basis of similarity of logic between the other rows. Optimization of the whole H-matrix is accomplished through logic sharing within a feasible operating time resulting in reduced area overhead. A detailed implementation using fuse technology is also proposed in this paper.

Development of a Matrix-based Context Awareness Model for Vehicle Environment (자동차 공간을 위한 Matrix기반의 상황인식 모델 개발)

  • Ko, Jae-Jin;Choi, Ki-Ho
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.8 no.6
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    • pp.187-195
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    • 2009
  • Recently, with the development of ubiquitous computing, the study and development about context awareness models is required for the application of ubiquitous environment. This paper presents the design and implementation of a matrix based context awareness model for vehicle environment. The matrix construction method using 5W1H and CAM (Context Awareness Model) expression is proposed for context awareness modeling. The system with the proposed model is implemented by Zigbee modules for the recognition of individual identification and position and a navigator for current spatial and temporal information of GPS. The result of experiments shows that the proposed model is available.

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Low Complexity Zero-Forcing Beamforming for Distributed Massive MIMO Systems in Large Public Venues

  • Li, Haoming;Leung, Victor C.M.
    • Journal of Communications and Networks
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    • v.15 no.4
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    • pp.370-382
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    • 2013
  • Distributed massive MIMO systems, which have high bandwidth efficiency and can accommodate a tremendous amount of traffic using algorithms such as zero-forcing beam forming (ZFBF), may be deployed in large public venues with the antennas mounted under-floor. In this case the channel gain matrix H can be modeled as a multi-banded matrix, in which off-diagonal entries decay both exponentially due to heavy human penetration loss and polynomially due to free space propagation loss. To enable practical implementation of such systems, we present a multi-banded matrix inversion algorithm that substantially reduces the complexity of ZFBF by keeping the most significant entries in H and the precoding matrix W. We introduce a parameter p to control the sparsity of H and W and thus achieve the tradeoff between the computational complexity and the system throughput. The proposed algorithm includes dense and sparse precoding versions, providing quadratic and linear complexity, respectively, relative to the number of antennas. We present analysis and numerical evaluations to show that the signal-to-interference ratio (SIR) increases linearly with p in dense precoding. In sparse precoding, we demonstrate the necessity of using directional antennas by both analysis and simulations. When the directional antenna gain increases, the resulting SIR increment in sparse precoding increases linearly with p, while the SIR of dense precoding is much less sensitive to changes in p.

Crystal Structure and Morphology of Nitride Precipitates in TiAl (TiAl에 석출한 질화물의 결정구조와 형태)

  • Han, Chang-Suk;Koo, Kyung-Wan
    • Korean Journal of Materials Research
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    • v.18 no.1
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    • pp.51-56
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    • 2008
  • The crystal structures and morphologies of precipitates in $L1_0$-ordered TiAl intermetallics containing nitrogen were investigated by transmission electron microscopy (TEM). Under aging at an approximate temperature of 1073 K after quenching from 1423 K, TiAl hardens appreciably due to the nitride precipitation. TEM observations revealed that needle-like precipitates, which lie only in one direction parallel to the [001] axis of the $L1_0$-TiAl matrix, appear in the matrix preferentially at the dislocations. Selected area electron diffraction (SAED) pattern analyses showed that the needle-shaped precipitate is perovskite-type $Ti_3AlN$ (P-phase). The orientation relationship between the P-phase and the $L1_0$-TiAl matrix was found to be $(001)_P//(001)_{TiAl}\;and\;[010]_P//[010]_{TiAl}$. By aging at higher temperatures or for longer periods at 1073 K, plate-like precipitates of $Ti_2AlN$ (H-phase) with a hexagonal structure formed on the {111} planes of the $L1_0$-TiAl matrix. The orientation relationship between the $Ti_2AlN$ and the $L1_0$-TiAl matrix is $(0001)_H//(111)_{TiAl}\;and\;_H//_{TiAl}$.

Delay-dependent Fuzzy H Controller Design for Delayed Fuzzy Dynamic Systems (시간지연 퍼지 시스템의 지연 종속 퍼지 H제어기 설계)

  • Lee, Kap-Rai
    • Journal of the Korean Institute of Intelligent Systems
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    • v.14 no.5
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    • pp.571-576
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    • 2004
  • This paper presents a delay dependent fuzzy $H_{\infty}$ controller design method for delayed fuzzy dynamic systems. Using delay-dependent Lyapunov function, the global exponential stability and $H_{\infty}$ performance problem arc discussed. A sufficient conditions for the existence of fuzzy controller is presented in terms of linear matrix inequalities(LMIs). A simulation example is given to illustrate the design procedures and performances of the proposed methods.

Design of Encoder and Decoder for LDPC Codes Using Hybrid H-Matrix

  • Lee, Chan-Ho
    • ETRI Journal
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    • v.27 no.5
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    • pp.557-562
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    • 2005
  • Low-density parity-check (LDPC) codes have recently emerged due to their excellent performance. However, the parity check (H) matrices of the previous works are not adequate for hardware implementation of encoders or decoders. This paper proposes a hybrid parity check matrix which is efficient in hardware implementation of both decoders and encoders. The hybrid H-matrices are constructed so that both the semi-random technique and the partly parallel structure can be applied to design encoders and decoders. Using the proposed methods, the implementation of encoders can become practical while keeping the hardware complexity of the partly parallel decoder structures. An encoder and a decoder are designed using Verilog-HDL and are synthesized using a $0.35 {\mu}m$ CMOS standard cell library.

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A p-channel LTPS active matrix process for OLED displays using a compensation circuit with three TFTs

  • Persidis, Efstathios;Baur, Holger;Pieralisi, Fabio;Fruehauf, Norbert;Marx, Thilo;Weitbruch, Sebastien;Schemmann, Heinrich;Roy, Philippe Le;Birnstock, Jan;Stubinger, Thomas;Vehse, Martin;Hofmann, Michael
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.403-408
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    • 2006
  • We have developed a four mask LTPS TFT p-channel process and fabricated active matrix backplanes based on a pixel circuit with three TFTs and one storage capacitor. Top emitting AMOLED displays have been produced to prove the working principle of the active matrix.

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