• 한국통신학회논문지
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• 제37권6B호
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• pp.464-473
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• 2012

본 논문에서는 무선 네트워크에서 네트워크 코딩을 재전송에 사용했을 때 얻을 수 있는 이득을 계산했다. 먼저 무선 네트워크에서 네트워크 코딩을 재전송에 활용했을 때 얻을 수 있는 전송 실패 확률을 수학적으로 구했고 이에 따른 다이버시티 차수를 노드 숫자와 수신 확률에 따라 변함을 보였다. 전송 실패 확률을 이용하여 전송실패 확률 ${\epsilon}$을 만족시키는 ${\epsilon}$-용량 (${\epsilon}$-outage capacity) 을 구하였고, 네트워크 코딩을 사용했을 때와 안 했을 때의 ${\epsilon}$-용량의 비율을 네트워크 코딩 이득이라 정의하였다. 그리고 네트워크 코딩 이득이 다이버시티 차수의 함수로 표현됨을 보였다. 노드 숫자가 무한하게 많아지게 되면 네트워크 코딩 이득이 점근적으로 $0.25{\epsilon}^{-1}$을 달성할 수 있음을 보였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1446-1449
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• 2005

The purpose of this study is the real-time shape measurement of three-dimensional object by using color coded information. The paper relates to non-contact optical measurements of surface profiles or displacements, because of optical measurement systems are advantageous over using mechanical sensing, their relatively high speed and non-destructive capabilities. Therefore is particularly useful for three dimensional sensing which requires high horizontal and vertical resolution of measurements over a wide range thereof. Each a red, blue, green by using a inherence colors of hue value are good point.

• 제어로봇시스템학회논문지
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• 제15권4호
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• pp.445-450
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• 2009

This paper presents a new mobile robot localization method for indoor robot navigation. The method uses hexagon distributed color-coded patches on the ceiling and a camera is installed on the robot facing the ceiling to recognize these patches. The proposed "cell-coded map", with the use of only seven different kinds of color-coded landmarks distributed in hexagonal way, helps reduce the complexity of the landmark structure and the error of landmark recognition. This technique is applicable for navigation in an unlimited size of indoor space. The structure of the landmarks and the recognition method are introduced. And 2 rigid rules are also used to ensure the correctness of the recognition. Experimental results prove that the method is useful.

• Journal of Advanced Marine Engineering and Technology
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• 제32권5호
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• pp.785-790
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• 2008

A technique for determining the feedback gain of the states feedback controller using a real-coded genetic algorithm(RCGA) is presented. It is concerned with the states error to the performance index of a RCGA. As for assessing the performance of the controller three performance criteria (ISE. IAE and ITAE) are adopted. And designing the controller involves a constrained optimization problem. Therefore a real-coded genetic algorithm incorporating the penalty strategy is used. The performance of the proposed method is demonstrated through a set of simulation about an inverted pendulum system.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 통신소사이어티 추계학술대회논문집
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• pp.281-284
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• 2003

Multi-code CDMA is an appropriate scheme for transmitting high rate data. However, dynamic range of the signal is large, and power amplifier with good linearity is required. Code select CDMA (CS/CDMA) is a variation of multi-code CDMA scheme that ensures constant amplitude transmission. In CS/CDMA input data selects multiple orthogonal codes, and sum of these selected codes are MPSK modulated to convert multi-level symbol into different carrier phases. CS/CDMA system employs level clipping to limit the number of levels at the output symbol to avoid hish density of signal constellation. In our previous work we showed that by encoding input data of CS/CDMA amplitude of the output symbol can be made constant. With this coding scheme, level clipping is not necessary and the output signal can be BPSK modulated for transmission. In this paper we show that the constant amplitude coded(CA-) CS/CDMA transmitter can be implemented using only logic gates, and the hardware complexity is very low. In the proposed transmitter architecture there is no apparent redundant encoder block which plays a major role in the constant amplitude coded CS/CDMA.

• 한국전자파학회지:전자파기술
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• 제6권4호
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• pp.3-10
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• 1995

In this paper, application of PTCM to 2FSK / 4PSK signals is studied. The generator polynomial of punctured trellis coded 2FSK / 4PSK, metric computation techniques, decoding complexity considerations are provided. Simulation results shows that PTCM of 2FSK / 4PSK archieves equal coding gain in com- parison to Padovani and Wolf's system with less decoding complexity.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.425-428
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• 2000

In this paper, we propose a new method based on SA(simulated annealing) with a fast algorithm for 3D image reconstructrion from the coded apereture images. The reconstructed images can be significantly improved by SA and to large computation cost of SA can be significantly reduced by the fast algorithm.

• 전자공학회논문지A
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• 제30A권11호
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• pp.11-20
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• 1993

In this paper, the asymtotic performance of a multiple trellis coded differential MPSK modulation over a satellite land mobile communication channel characterized by additive white Gaussian noise (AWGN) and fading is presented. Simple formulas for the bit error probability are derived for systems using differential MTCM over Rician and Rayleigh fading channel. Also are given numerical results which are more indicative of the actual system performance. Finally, the comparisons with results previously obtained for the uncoded and conventional trellis coded modulation are provided.

• 한국정보통신학회논문지
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• 제6권4호
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• pp.544-551
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• 2002

본 논문에서는 레일리 페이딩 상태, 라이시안 페이딩 상태, 쉐도우 라이시안 페이딩 상태로 구성된 혼합페이딩 채널에서 DS/CDMA-BPSK 시스템의 오율 성능을 분석하였다. 결과로부터 본 논문에서 제시한 혼합 페이딩 채널 모델은 다양한 채널 상태을 표현하는데 적절함을 알 수 있었다. 그리고 혼합페이딩 채널에서는 무선 채널의 점유 확률과 쉐도우 심도가 시스템의 BER 성능에 많은 영향을 준다는 것을 알 수 있었다. 또한 Reed-Solomon 부호를 적용한 DS/CDMA-BPSK 시스템은 동시 사용자 간섭과 혼합 페이딩 채널에 매우 강인함을 알 수 있었다.

• 한국항행학회논문지
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• 제10권3호
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• pp.213-218
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• 2006

본 논문에서는 임펄스 간섭과 광대역 무선통신 채널에서 OFDM/FHMA 하이브리드 시스템을 분석하고 음성 및 데이터 전송 서비스를 만족하기 위한 성능 보상 방안으로 터보 부호를 적용하여 열화 된 시스템의 성능을 개선하였다. 또한, 다이버시티 기법과 터보 부호를 적용했을 때의 시스템 성능을 비교하였다. 얻어진 결과로부터 제안된 하이브리드 OFDM/FHMA 시스템은 일반적인 OFDM/FHMA 시스템과 비교하면 10배 이상의 성능이 향상되는 것으로 분석 되었다.