• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2013년도 춘계학술대회 논문집
• /
• pp.1295-1296
• /
• 2013

• 한국에너지공학회:학술대회논문집
• /
• 한국에너지공학회 2007년도 추계학술 발표회
• /
• pp.90-95
• /
• 2007

• 천문학회보
• /
• 제35권1호
• /
• pp.50.2-50.2
• /
• 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.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제12권3호
• /
• pp.331-340
• /
• 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.

• 한국ITS학회 논문지
• /
• 제8권6호
• /
• pp.187-195
• /
• 2009

최근 유비쿼터스 컴퓨팅의 발전과 함께 유비쿼터스 환경에 적용할 수 있는 상황인식 모델에 대한 연구 개발이 요구되고 있다. 본 논문은 자동차 공간을 위한 매트릭스 기반 상황인식 모델을 설계하고 구현하였으며, 상황인식 모델링을 위해 5W1H와 CAM 수식을 이용한 매트릭스 구성 방법을 제안하였다. 개인 식별과 위치 확인을 위한 Zigbee 모듈과 GPS의 현재의 공간과 시간 정보를 위한 네비게이터를 이용하여 제안된 모델을 이용한 시스템을 구현하였다. 시험 결과 제안된 모델이 유용 가능함을 보였다.

• Journal of Communications and Networks
• /
• 제15권4호
• /
• pp.370-382
• /
• 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.

• 한국재료학회지
• /
• 제18권1호
• /
• pp.51-56
• /
• 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 $(0001)_H//(111)_{TiAl}\;and\;_H//_{TiAl}$.

• 한국지능시스템학회논문지
• /
• 제14권5호
• /
• pp.571-576
• /
• 2004

본 논문은 시간지연을 갖는 비선형 시스템에 대한 지연 종속 $H_{\infty}$ 제어기 설계 방법을 제안한다. 지연 종속 Lyapunov 함수를 이용하여 지수 함수적 안정화와 $H_{\infty}$ 성능 문제를 고려한다. 제어기의 존재성에 대한 충분조건을 유도하고 선형행렬부등식(LMI: linear matrix inequality)으로 나타낸다. 제어기 설계는 병렬 분산 보상의 개념을 이용하고, 필터는 LMI 해를 구함으로써 바로 구할 수 있다. 제안한 방법의 설계과정 및 타당성을 시뮬레이션 예제를 통하여 나타낸다. 지연종속 제어기는 제어기 존재 조건을 나타내는 선형 행렬 부등식에 시간지연항의 크기를 포함하고 있으므로 시간지연항의 크기에 상관없이 시스템을 안정화시키는 기존의 지연 독립적인 제어기보다 더 효과적인 설계 방법이다.

• ETRI Journal
• /
• 제27권5호
• /
• pp.557-562
• /
• 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.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
• /
• pp.403-408
• /
• 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.