• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.126-130
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• 2005

In this paper, a low-complexity maximum-likelihood (ML) decoder based on QR decomposition, called real-valued LCMLDec decoder or RVLCMLDec for short, is proposed for the Vertical Bell Labs Layered Space-Time (V-BLAST) architecture, a promising candidate for providing high data rates in future fixed wireless communication systems [1]. Computer simulations, in comparison with other detection techniques, show that the proposed decoder is capable of providingthe V-BLAST schemes with ML performance at low detection complexity.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.12-16
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• 2008

In this paper, we study precoding techniques for co-channel interference suppression in multiuser MIMO systems. DPC is optimal techniques to achieve the system capacity of multiuser MIMO downlink channels. DPC is not proper in practical wireless systems because complexity is very high. So block diagonal precoding for multiuser MIMO downlink channel is studied. The block diagonal precoding is used to suppress co-channel interference between multiuser. Block diagonal precoding method, whose complexity is reduced by modified null space operation, change multiuser MIMO channel to multiple single-user MIMO channel. We also use V-BLAST decoder in receiver. V-BLAST decoder can achieve increased system capacity in proportion to the number of users. We show improved system performance by using computer simulation.

• Journal of information and communication convergence engineering
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• 제3권2호
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• pp.76-79
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• 2005

In this paper, a low-complexity maximum-likelihood (ML) decoder based on QR decomposition, called real-valued LCMLDec decoder or RVLCMLDec for short, is proposed for the Vertical Bell Labs Layered Space-Time (V-BLAST) architecture, a promising candidate for providing high data rates in future fixed wireless communication systems [1]. Computer simulations, in comparison with other detection techniques, show that the proposed decoder is capable of providing the V­BLAST schemes with ML performance at low detection complexity

• 한국통신학회:학술대회논문집
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• 한국통신학회 2006년도 하계종합학술발표회 논문 초록집
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• pp.242-242
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• 2006

• 한국통신학회:학술대회논문집
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• 한국통신학회 2004년도 추계종합학술대회 논문 초록집
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• pp.73-73
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• 2004

• 화약ㆍ발파
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• 제28권1호
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• pp.19-26
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• 2010

이 논문은 필리핀 석회석 광산에 적용한 연구 결과로서 이 광산에서는 파쇄석 입도분포가 좋지 않고 벽면의 유지나 파쇄석 더미의 분산이 불량하였다. 기폭패턴을 대각선 방식에서 V 타입으로 바꾸고 전색장을 조정하여 저항과 가스압의 유지기간을 향상시켰다. 이를 통하여 발파결과가 향상되었다. 특히 공당발파영역이 넓어진 것으로써 그 성과를 확인할 수 있다. 공당발파영역은 기존의 $8.96m^2$에서 $12m^2$로 넓어졌다. 화약계수는 증가하였고 대괴의 수는 감소하였으며, 전방적재기의 행정시간이 감소하였다. 또 공전 시간이 줄었으며 적재높이가 향상되었다.

• 한국정보통신학회논문지
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• 제13권11호
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• pp.2405-2411
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• 2009

V-BLAST의 신호 복원을 위한 기법으로는 MMSE, ZF, ML 등이 있으며, 이중 ML 기법이 최적의 성능을 나타낸다. 그러나 ML 기법은 송신안테나 수와 변조차수에 따라 연산복잡도가 지수적으로 증가하는 문제점이 있다. 본 논문에서는 V-BLAST의 신호 복원을 위해 보다 낮은 복잡도를 갖는 저 복잡도 선형 ML검출 기법을 제안하고 이 시스템을 기존의 검출 기 법들과 BER과 연산량 측면에서 비교, 분석하였다. 분석결과 제안한 검출기법의 BER 성능은 ZF과 MMSE 검출기법보다 우수하였고 ML 검출기법과는 유사하였다. 그러나 연산량 측면에서는 제안한 시스템의 연산량이 ML 검출기법의 연산량보다 약 50%정도 적었다. 이 결과들을 통해 본 논문에서 제안한 저 복잡도 선형 ML 검출기법이 기존의 검출기법 보다 우수함을 알 수 있다.

• 산업기술연구
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• 제20권A호
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• pp.257-267
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• 2000

It was difficult to apply conventional excavation methods in some sections from Seoul to Pusan high speed rail road construction of 1 lot 2, due to highway concrete road, gas pipe, water pipe and nearby factories with automatic control system machine. To excavate safely and efficiently in these sections new blast patterns were employed within allowable blast vibration level, by test blast and controlled vibration by sequential blast. Behaviors of the rock mass including convergence and displacement around tunnel were measured with construction works and the crack width in concrete wall was also monitored for controlling allowable limits. The results can be summarized as follow : 1. The allowable blast vibration level in structure site is less 1.0cm/sec for highway concrete, 0.5 cm/sec for gas pipe, water pipe and building housing and 0.3 cm/sec for automatic control system machine. 2. The convergence displacement, single rod extensometer and multi rod extensometer around tunnel and cracks in concrete wall were measured, it was confirmed that the measured values were converged within allowable level. 3. The empirical formular of ground vibrations with 90% confidence lines for PD-3 was given as follow. $$V_{90%}=45.549({\frac{D}{\sqrt{W}}})^{-1.353}$$

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2005년도 추계 학술발표회
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• pp.15-20
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• 2005

Locations of silicon accumulation in rice leaves and its possible association with resistance to rice blast were investigated by analytical electron microscopy and atomic force microscopy. A blast-susceptible cultivar, Jinmi, and partially resistant cultivars, Hwaseong and Suwon345, were grown under a hydroponic culture system with modified Yoshida's nutrient solution. Electron-dense silicon layers were frequently found beneath the cuticle in epidermal cell walls of silicon-treated plants. Increasing levels of silicon were detected in the outer regions of epidermal cell walls. Silicon was present mainly in epidermal cell walls, middle lamella, and Intercellular spaces within subepidermal tissues. Furthermore, silicon was prevalent throughout the leaf surface with relatively small deposition on stomatal guard cells in silicon-treated plants. Force-distance curve measurements revealed relative hardness and smaller adhesion force in silicon-treated plants (18.65 uN) than control plants (28.39 uN). Moreover, force modulation microscopy showed higher mean height values of elastic Images In silicon-treated plants(1.26 V) than in control plants (0.44 V), implying the increased leaf hardness by silicon treatment. These results strongly suggest that silicon-induced cell wall fortification of rice leaves may be closely associated with enhanced host resistance to blast.

• 한국정보통신학회논문지
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• 제9권7호
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• pp.1452-1457
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• 2005

QR Decomposition-based (QRD) decoding class에서는, 시스템 성능이 에러 전송에 민감하다. 그러므로 이전의 layer들을 정확하게 디코딩하는 것이 중요하다. 에러 전송에 민감하지 않도록 하는 접근 방법 중의 하나가 layer들의 최적 디코딩 order를 제안하는 것이다. 본 논문에서는 새로운 extended-list Sorted QRD-based (SQRD) 디코딩 접근 방법을 제안한다. 제안되는 디코딩 방법에는 약간의 첫째 layer들의 solution이 상당히 가능성 있는 solution들의 list로 확장된다. 이렇게 함으로 가장 낮은 layer의 diversity가 증가된다. 결과적으로 시스템 성능이 다른 것들의 에러 전송보다 덜 민감하게 된다. 제안되는 방법은 컴퓨터 시뮬레이션 결과로 증명된다.