• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.11a
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• pp.252-253
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• 2014

최근 채널 효율을 향상시키기 위하여 다중안테나(MIMO, multi-input multi-output) 기술이 연구되고 있다. 다중안테나 기술은 송 수신 안테나 개수를 증가시켜 수신 성능을 향상시키고 대역 효율을 향상시키지만 송신 안테나 개수를 늘려야만 대역 효율을 증가시킬 수 있으므로 기존 방송 시스템에 적용하기에는 비용이 많이 드는 단점이 있다. 이에 본 논문은 방송 시스템에 적합한 SIMO(single-input multi-output) 시스템에 FTN(faster than Nyquist)을 적용하여 대역 효율을 증가시키고 수신 성능을 향상시키고자 한다. 또한 MRC(maximum ratio combining) 및 경판정(hard decision)을 적용하여 수신 안테나 개수에 따른 수신 성능을 컴퓨터 실험을 통하여 알아본다.

• The KIPS Transactions:PartC
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• v.10C no.1
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• pp.27-32
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• 2003

An efficient soft-decision decoding algorithm for binary block codes it proposed. The proposed soft-decision decoding algorithm is implemented by a series of hard-decision decoding process. By the hard-decision decoding result, the candidate codewords are efficiently searched for A new decoding method, which prevents the missing of the candidate codeword, is proposed. Also, the method fir reducing complexity is developed. This method removes the practical complexity increase caused by the improved algorithm. There facts are confirmed by the simulation results for binary (63, 36) BCH code.

• Journal of Information Management
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• v.20 no.1
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• pp.139-157
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• 1989

일본(日本) 과학기술청(科學技術廳)에서는 장래의 과학기술정보(科學技術情報) 유통(流通)시스템에 정보기술(情報技術)을 활용하기 위한 조사를 실시하였으므로 그 개요를 소개한다. 조사는 전문가(專門家)로 부터의 청취 그리고 연구개발(硏究開發) 담당자(擔當者)와 각 기관정보관리부문(機關情報管理部門)에 대한 설문조사 및 문헌조사 등의 결과를 중심(中心)으로 정보유통기술(情報流通技術), 과학기술정보(科學技術情報)의 이용형태(利用形態)의 장래전망(將來展望) 등을 근거(根據)로 새로운 유통(流通)시스템의 검토(檢討)를 함과 동시에 경판신(京阪神) (경도(京都), 대판(大阪), 신호(神戶)의 약칭) 지역(地域)에 있어서의 과학기술정보(科學技術情報)에 대해 그 활용(活用)의 요구파악(要求把握)과 유통(流通)시스템의 동향(動向)을 분석(分析)하고 지역(地域)에 있어서의 정보유통촉진(情報流通促進)을 위한 과제정리(課題整理)를 하여 종합적(綜合的)으로 분석(分析)하였다.

• Journal of the Korean Wood Science and Technology
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• v.24 no.3
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• pp.80-89
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• 1996

Tripitaka Koreana was made during Koryo Dynasty from 1236 to 1251 A.D. Buddhist scriptures were engraved on 81.340 wooden plates. This study was made to identify species in these archaeological wooden plates using light and scanning electron microscopes. The results were as follows more than 62% of whole specimens investigated was Prunus sp., which was used in wooden plate 64% and wooden plate edge 56%, Pyrus sp. was used 13% of whole specimens and 31% of wooden plates. Therefore, 75% of whole Tripitaka Koreana was made by these two species. Acer sp., Betula sp., Machilus sp., Cornus sp., Daphnilhyllum sp., Prunus sp. were also identified but extreamly rare. Especially Machilus sp. and Daphnilhyllum sp. originally distributed in subtropical zone of west and south coast in Korea were identified, suggested strongly another engraving place of Tripitaka Koreana, Namhae bunsadogam.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.07a
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• pp.337-338
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• 2012

다중 안테나 전송 기술은 추가적인 대역폭의 필요 없이 다이버시티 이득을 얻을 수 있는 장점이 있다. 이러한 이유로 차세대 방송기술 및 이동 통신기술에서는 대용량 데이터 전송을 위하여 다중 안테나 전송기술을 채택하고 있다. 또 다른 차세대 무선 통신 시스템의 큰 특징은 무선 통신 환경에서 발생하는 다중 경로 및 무선 경로 페이딩에 의한 성능 저하를 극복하기 위하여 연판정 검출 값을 반복적으로 사용하는 오류정정부호의 사용에 있다. 이 경우에 수신단에서 MIMO 검출 후 수행되는 터보 부호에 대한 복호 과정에서 연판정 입력이 필요하고, 이 연판정 입력 값이 복호 성능에 큰 영향을 미치기 때문에 효율적인 연판정 검출 값이 필요로 한다. 본 논문에서는 MIMO 검출 후 M-ary QAM 복조시 경판정 경계를 이용한 연판정 검출방법을 이용하여 적은 연산을 요구하는 M-ary QAM 의 연판정 검출 방식을 제안한다.

• Conservation Science in Museum
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• v.4
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• pp.41-46
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• 2003

Remarkable features, such as neck guard and plate designed the shape of a duck, are identified in the process of conservation for the plate armour excavated from the No. 2 tomb, Daeseong-dong, Gimhae. We considered that should be careful for treating this kind of artifacts, especially when restoring to its original. For this purpose, we thoroughly studied the endurance of materials for restoration and applied the techniques in reference to the traditional method.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.97-100
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• 2005

The purpose of this study is to apply the partial-size die forming process to actual segment head farming process of semi-ellipsoidal heads and to verify the availability of the suggested forming method. The initial curvature for the preliminary forming process was determined through anticlastic behavior of plate bending and the partial-size die for final forming was designed based on the results of springback analysis using F.EA. From the results of actual forming, it was concluded that die design was appropriate and proposed forming process would be successfully applied to actual forming jobs.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.349-352
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• 2008

In this study, a design method of developed shape for double-curved pressure vessel segment heads was proposed in consideration of in-plane strain induced by forming works. In order to obtain the developed shape of double-curved plate, at first, the segments are subdivided into elements and then they are stacked into a series of strips producing the outline of the approximately developed shape. The developed shape was determined by imposing the in-plane displacement obtained from forming analysis and regression analysis on the outline of the approximately developed shape. The validation of the proposed design method was verified by applying it to the actual products.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.2
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• pp.268-277
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• 2001

In this paper, the system performance with the convolution code using a Viterbi decoding and the one tap LMS equalizer applied to the OFDM system, which is suitable for IEEE 802.1la wireless LAN in indoor wireless channel, is analyzed through computer simulation. Indoor wireless channel is modeled as Rician fading channel, and QPSK and 16QAM scheme are used for subchannel modulation. In Rician fading channel with the power ratio of the direct path signal to the scattered signals, K=5 dB, BER of $10^{-4}$ is satisfied if the SNRs of the QPSK/OFDM and the 16QAM/OFDM are 8.6 dB and 19.2 dB in hard decision and 5.3 dB and 9.8 dB in soft decision, respectively. Compared with convolution code scheme, it is observed that 16QAM/OFDM system with the one tap LMS equalizer has the performance improvement of 8.6 dB and 2 dB in hard decision and soft decision, respectively.

• Journal of the Korean Wood Science and Technology
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• v.35 no.1
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• pp.51-63
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• 2007

The biodeterioration behaviors of wooden parts in the Janggeongpanjeon built in 15 century were investigated according to the types of wood species, positions and parts of wooden column, and environmental conditions. It was found that a high differences of deterioration in the progressing levels of wood decay, according to the types of wood species, positions and parts of wooden column, and environmental conditions. The decay levels were high in the contacted areas with stone foundation which are about up to 8~40 cm above it, although it was shown the many of wooden parts of the round columns are still good condition. In the case of decay type, it was shown the brown-rot in many of the columns at outside of building which made of hardwoods. The decay in position of the columns was most serious in the directions of east-north, west-north and north. It was also indicated that the durability of Zelkova serrata was higher than other wood species of the round columns, while it was in inferior anti-insects.