• 방송공학회논문지
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• 제1권1호
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• pp.29-34
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• 1996

차등적 오류 방지는 전송되는 정보에 따라 채널에서 오류가 발생했을 때 미치는 영향이 다른 것을 이용하여 채널 오류에 민감한 정보를 다른 정보보다 강력하게 채널 오류로부터 보호하는 방법이다. 그러나 채널에서 오류가 없다는 가정하에 LBG 알고리듬으로 설계한 벡터 양자화 신호에 차등적 오류 방지를 그대로 적용할 수 없다. 따라서 본 논문에서는 이러한 벡터 양자화 신호의 전송에서 차등적 오류 방지를 적용할 수 있도록 부호 벡터에 체계적으로 이진 인덱스를 할당하는 기법을 제안하였다. 또한 제안한 기법을 벡터 양자화 한 1차 Gauss-Marcov 신호의 전송에 중요한 정보의 비율을 50%로 하여 적용하였다.

• 한국통신학회논문지
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• 제33권11C호
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• pp.874-879
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• 2008

[1]에서 LCZ 수열군의 2배 확장을 제안하였다. 본 논문에서는 [1]에서의 2배 확장방법을 일반화하는 새로운 확장방법을 제안한다. 이 생성방법을 사용하면 인수가 (N,M,L,${\epsilon}$)인 q진 LCZ 수열군은 인수가 (pN,pM,p[(L+1)/p]-1,p${\epsilon}$)인 q진 LCZ 수열군이 된다. 이 때, p는 소수이고 p는 q의 약수다. 특히 L${\equiv}$p-1modp일 때, 확장된 q진 LCZ 수열군의 인수는 (pN,pM,L,p${\epsilon}$)이 된다.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1991년도 학술발표회 논문집
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• pp.151-156
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• 1991

In this paper, we propose a new algorithm for designing the R-G filter that has optimum performance in terms of mean square sidelobe level(MSSL) for the Barker code. The advantage of the conventional R-G filter lies in its simple structure so that it can be easily implemented. However, the conventional R-G filter dose not have optimum performances in terms of peak sidelobe level(PSL), mean sidelobe level(MSL), and MSSL. Recently, a(R-G)LP filter of which filter coefficients are obtained by the linear programming algorithm was proposed and known to have optimum performance in PSL. The proposed (R-G)LS filter keeps the simple structure of the conventional R-G filter and has the filter coefficients that minimizes the sidelobe in the least square sense. The analytic results show that the proposed (R-G)LS filter has better performances than the conventional R-G filter in terms of PSL, MSL, and MSSL. Compared with (R-G)LP filter, the proposed (R-G)LS filter has better performances in terms of MSL and MSSL. The proposed filter design algorithm can be applied to the other binary codes such as truncated pseudonoise(PN) codes and concatenated codes.

• 복식문화연구
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• 제18권5호
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• pp.942-959
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• 2010

The Realization of Ubiquitous is achieved by magic mirror and it is required more concrete study to realize it's functionality. Especially its function of professional fashion co-ordinator for managing the appearance could be of further use. The Objective of this Study is to establish RFID chip data base to put into a computer for making use of the functionality of the magic mirror aiming at suggesting the available information on the total fashion co-ordination. I sought firstly the code with binary system determining the criteria of accessories to be input in a RFID chip. Secondly, as the image with cloth is an important element for the total fashion co-ordination, desired co-ordination among the emphasis, harmony, character, season and accent can be made selectable classifying into a limit element and a common element to extract the codes. Thirdly, necessary conditions were given to the generated codes using Visual C++ program of Microsoft and the extracted codes as per groups were compared and analyzed.

• Journal of Communications and Networks
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• 제15권3호
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• pp.276-282
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• 2013

Self-encoded spread spectrum (SESS) is a novel modulation technique that acquires its spreading code from a random information source, rather than using the traditional pseudo-random noise (PN) codes. In this paper, we present our study of the SESS system performance under pulsed-noise jamming and show that iterative detection can significantly improve the bit error rate (BER) performance. The jamming performance of the SESS with correlation detection is verified to be similar to that of the conventional direct sequence spread spectrum (DSSS) system. On the other hand, the time diversity detection of the SESS can completely mitigate the effect of jamming by exploiting the inherent temporal diversity of the SESS system. Furthermore, iterative detection with multiple iterations can not only eliminate the jamming completely but also achieve a gain of approximately 1 dB at $10^{-3}$ BER as compared with the binary phase shift keying (BPSK) system under additive white gaussian noise (AWGN) by effectively combining the correlation and time diversity detections.

• 한국통신학회논문지
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• 제19권5호
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• pp.971-980
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• 1994

현존하는 셀룰라 이동통신의 가입자 수용 한계로 부호분할다원접속(CDMA) 방식을 사용하는 디지틀셀룰라 통신 방식이 거론되고 있다. EIA/TIA 잠정 표준안인 CDMA 시스팀에서는 동일한 확살부호를 전체 시스팀에 사용하지만 각 기지국에 확산부호의 위상옵셉(phase-offset)을 다르게 배분함으로써 이동국은 기지국으로 송신된 신호를 구변하도록 하고 있다. 그러나 확산부호의 위상옵셉이 기준이 되는 영옵셉(zero-offset) 부호를 임의로 설정하고 있다. 본 논문은 확산부호의 기준 부호를 정하는 방법을 제시하고, 기준 부호로부터 위상을 이전(shift) 시킨 부호 사이의 위상옵셉을 쉽게 계산하는 방법을 제시한다.

• ETRI Journal
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• 제37권3호
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• pp.595-605
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• 2015

This paper proposes a robust, imperceptible block-based digital video watermarking algorithm that makes use of the Speeded Up Robust Feature (SURF) technique. The SURF technique is used to extract the most important features of a video. A discrete multiwavelet transform (DMWT) domain in conjunction with a discrete cosine transform is used for embedding a watermark into feature blocks. The watermark used is a binary image. The proposed algorithm is further improved for robustness by an error-correction code to protect the watermark against bit errors. The same watermark is embedded temporally for every set of frames of an input video to improve the decoded watermark correlation. Extensive experimental results demonstrate that the proposed DMWT domain video watermarking using SURF features is robust against common image processing attacks, motion JPEG2000 compression, frame averaging, and frame swapping attacks. The quality of a watermarked video under the proposed algorithm is high, demonstrating the imperceptibility of an embedded watermark.

• ETRI Journal
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• 제32권4호
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• pp.493-502
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• 2010

The operation time of an encoder is one of the critical implementation issues for satisfying the timing requirements of Long Term Evolution (LTE) systems because the encoder is based on binary operations. In this paper, we propose a design and implementation of a latency efficient encoder for LTE systems. By virtue of 8-bit parallel processing of the cyclic redundancy checking attachment, code block (CB) segmentation, and a parallel processor, we are able to construct engines for turbo codings and rate matchings of each CB in a parallel fashion. Experimental results illustrate that although the total area and clock period of the proposed scheme are 19% and 6% larger than those of a conventional method based on a serial scheme, respectively, our parallel structure decreases the latency by about 32% to 65% compared with a serial structure. In particular, our approach is more latency efficient when the encoder processes a number of CBs. In addition, we apply the proposed scheme to a real system based on LTE, so that the timing requirement for ACK/NACK transmission is met by employing the encoder based on the parallel structure.

• 천문학논총
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• 제30권2호
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• pp.113-114
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• 2015

Recent high-resolution, high-sensitivity observations of protostellar jets have shown many to possess an underlying 'wiggle' structure. HH 211 is one such example where recent sub-mm observations revealed a clear reflection-symmetric wiggle. An explanation for this is that the HH211 jet source is moving as part of a protobinary system. Here we test this assumption by simulating HH211 through 3D hydrodynamic simulations using the pluto code with a molecular chemistry and cooling module, and initial conditions based on an analytical model derived from SMA observations. Molecular chemistry allows us to accurately plot synthetic molecular emission maps and position-velocity diagrams for direct comparison to observations, enabling us to test the observational assumptions and put constraints on the physical parameters of HH211. Our preliminary results show that the reflection-symmetric wiggle can be recreated through the assumption of a jet source being part of a binary system.

• 한국통신학회논문지
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• 제15권2호
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• pp.112-123
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• 1990

본 논문은 한글 문자인식을 위하여 중첩형상데이타에 의한 한글 패턴의 굴곡 특징점과 정점검출에 관하여 논한 것이다. 입력된 2진 문자패턴을 거리변환법에 의한 중첩데이타로 변환하고, 데이터의 특성분석에 의한 변환값의 새로운 파일로 구성하였다. 이 두 데이터 파일로 한글 인식에 유용한 정점들을 검출하는 알고리즘을 제안하였다. 이 알고리즘에서는 오인식의 원인이 되는 돌기부분의 제거, 자소 접촉 부분의 분리, 굴곡 특징 변환값에 따른 코드를 부여하도록 하였따. 여기서의 출력은 한글 문자인식에 활용될 수 있는 형태로 하였다.