• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.298-301
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• 2000

We discuss the iterative methods for linear systems on a single processing node of the HITACHI SR8000. Each processing node of the SR8000 is a shared memory parallel computer which is composed of eight RISC processors with a pseudo-vector facility. We implement highly optimized codes for basic linear operations including a matrix-vector product and apply them to the conjugate gradient (CG) and the conjugate residual (CR) methods for linear systems. Our tuned codes for both method score nearly 50% of the theoretical peak performance, which is the best in the sense that it corresponds to an asymptotic performance of the inner product.

• 전기전자학회논문지
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• 제26권3호
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• pp.506-509
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• 2022

비밀 공유 기법에서는 비밀 정보가 사용자들에게 분산되어 저장되고, 특정 허가된 사용자의 부분 집합으로부터만 비밀이 재합성될 수 있어야 한다. 이를 위해서는 서로 다른 부호어들 사이의 정보가 종속되지 않아야 한다. 극소 부호는 선형 블록 부호의 일종으로서 이러한 비밀 정보들이 상호 종속되지 않게 분산하는 역할을 한다. 본 논문에서는 극소 부호의 새로운 확장 기법을 제시한다. 임의의 벡터와 극소 부호의 곱을 통해 새로운 길이와 해밍 무게를 가지는 새로운 극소 부호가 생성된다. 이를 통해 기존에 알려지지 않은 파라미터를 가지는 극소 부호들을 제공할 수 있다.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1985년도 춘계학술발표회논문집
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• pp.6-8
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• 1985

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.999-1000
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• 2006

The LDPC Code is focusing a powerful FEC(Forward Error Correction) codes for 4G Mobile Communication system. LDPC codes are used minimizing channel errors by modeling AWGN Channel as VDSL system. The performance of LDPC code is better than that of turbo code in long code word on iterative decoding algorithm. LDPC code are encoded by sparse parity check matrix. there are decoding algorithms for a LDPC code, Bit Flipping, Message passing, Sum-Product. Because LDPC Codes use low density parity bit, mathematical complexity is low and relating processing time becomes shorten.

• 전자공학회논문지S
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• 제34S권2호
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• pp.1-10
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• 1997

In this paper, an improved lower bound on the burst-error correcting capability of th ecyclic product code is presented and through the analysis of this new bound clustered cyclic product (CCP abbr.)code is proposed. The CCP code, to improve the burst-error correcting capability, combines the idea of clustering and the transmission method of cyclic product code. That is, a cluster which is defined in this paper as a group of consecutive code symbols is employed as a new transmission unit to the code array transmission of cyclic product code. the burst-error correcting capability of the CCP code is improved without a loss in the random-error correcting capability and performance comparison in the digital video camera records (DVCR) system shows the superiority of the proposed CCP code over conventional product codes.

• Journal of Communications and Networks
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• 제6권3호
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• pp.258-268
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• 2004

We demonstrate rotationally invariant space-time (ST) trellis codes with a 4-D rectangular signal constellation for data transmission over fading channels using two transmit antennas. The rotational invariance is a good property to have that may alleviate the task of the carrier phase tracking circuit in the receiver. The transmitted data stream is segmented into eight bit blocks and quadrature amplitude modulated using a 256 point 4-D signal constellation whose 2-D constituent constellation is a 16 point square constellation doubly partitioned. The 4-D signal constellation is simply the Cartesian product of the 2-D signal constellation with it-self and has 32 subsets. The partition is performed on one side into four subsets A, B, C, and D with increased minimum-squared Euclidian distance, and on the other side into four rings, where each ring includes four points of equal energy. We propose both linear and nonlinear ST trellis codes and perform simulations using an appropriate multiple-input multiple-output (MIMO) channel model. The 4-D ST codes constructed here demonstrate about the same frame error rate (FER) performance as their 2-D counterparts, having however the added value of rotational invariance.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1984년도 추계학술발표회논문집
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• pp.11-14
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• 1984

When the received sequence is not identical to the transmitted code word due to the channel nose effect, it is necessary to detect and correct errors. In this paper, it is shown how to construct the encoder and the decoder using cyclic product codes. this system combines random and burst error correction and is easily decodable. Performance has been obtained as expected.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 가을 학술발표회 논문집
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• pp.211-218
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• 2002

An entity-based integrated design product and process model uses product and process entities to describe design information and design activities, respectively. The concepts and notation for product and process entities in the entity-based integrated design model are similar to the concepts of object-oriented programming languages such as C++ and Smalltalk. This paper uses C++ to program an entity-based integrated design model for building frames structures. The design information and activities involved in the three dimensional building space, the locations of frames, and the grouping of frames represented as entities in the entity-based integrated design model are transformed to C++ codes. Each product or process entity can be basically transformed to an class. The attributes of an entity can be defined as variables and member functions of a class.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.43-44
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• 2009

이 논문에서는 3차원 교량정보모델을 콘크리트 박스교량에 대해서 구축하고 그 활용의 대표적인 예로 3차원 모델에 연동되는 견적시스템을 개발한 결과를 정리하였다. 콘크리트 박스 교량에 대해 물량을 산출할 시에는 2D 도면을 활용하여 PBS(Product Breakdown Structure)에 따른 표준분류체계를 활용한 3D 형상모델 객체를 형성하였으며, 분류에 따른 객체의 물량 정보 데이터를 활용하여 견적까지 활용할 수 있도록 하였다. 콘크리트 물량 및 철근 물량을 산출하는 프로세서를 개발하고 이를 검증하는 시범체계를 구축하여 적용하였다. 철근의 최적화 등이 부가적인 기능으로 물량 절감 및 제작 상세 표준화 방안이 제시되었다.

• Smart Structures and Systems
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• 제17권4호
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• pp.577-591
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• 2016

In this study, the transfer length of 2400 MPa, seven-wire high-strength steel strands with a 15.2 mm diameter in pretensioned prestressed concrete (PSC) beams utilizing high strength concrete over 58 MPa at prestress release was evaluated experimentally. 32 specimens, which have the variables of concrete compressive strength, concrete cover depth, and the number of PS strands, were fabricated and corresponding transfer lengths were measured. The strands were released gradually by slowly reducing the pressure in the hydraulic stressing rams. The measured results of transfer length showed that the transfer length decreased as the concrete compressive strength and concrete cover depth increased. The number of strands had a very small effect, and the effect varied with both the concrete cover depth and concrete strength. The results were compared to current design codes and transfer lengths predicted by other researchers. The comparison results showed that the current transfer length prediction models in design codes may be conservatively used for 2400 MPa high-strength strands in high-strength concrete beams exceeding 58 MPa at prestress release.