• The Transactions of the Korea Information Processing Society
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• v.5 no.7
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• pp.1933-1942
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• 1998

분류 벡터 양자화(classified vector quantization: CVQ)〔2의 부코드북을 설계함에 있어서, 경쟁 학습 네트워크〔5〕-〔7〕 는 소속도의 이분법적 표현으로 상당한 소속도를 가지는 벡터들이 학습 과정에 무시되는 경향을 가진다. 이를 개선하기 위해 제안된 퍼지 경쟁 학습 네트워크〔8〕는 각 클러스터가 연속적인 소속도를 가진다는 개념을 도입하여 이와 같은 문제들을 해결했다. 그러나 퍼지 경쟁 학습 네트워크를 CVQ에 적용할 경우, 각 부코드북의 크기를 시행착오로 결정해야 하는 문제점을 여전히 가지고 있으며, 이러한 문제점들의 개선을 위하여 본 논문에서는 수정 퍼지 경쟁 학습 네트워크(modified fuzzy competitive learning network)를 제안한다. 수정 퍼지 경쟁 학습 네트워크는 퍼지 학습 네트워크가 가지는 이 분법적 소속도를 연속적인 소속도로 확장하여, 학습 과정중에 나타날 수 있는 지역 최소점 도달을 억제하였다.

• The Journal of the Acoustical Society of Korea
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• v.11 no.1
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• pp.22-34
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• 1992

There exists a transform trellis code that is optimal for stationary Gaussian sources and the squared-error distortion measure at all rates. In this paper, we train an asymptotically optimal version of such a code to obtain one which is matched better to the statistics of real world data. The training algorithm uses the M algorithm to search the trellis codebook and the LBG algorithm to update the trellis codebook. We investigate the trained transform trellis coding scheme for the first-order AR(autoregressive) Gaussian source whose correlation coefficient is 0.9 and actual speech sentences. For the first-order AR source, the achieved SNR for the test sequence is from 0.6 to 1.4 dB less than the maximum achievable SNR as given by Shannon's rate-distortion function for this source, depending on the rate and surpasses all previous known results for this source. For actual speech data, to achieve improved performance, we use window functions and gain adaptation at rate 1.0 bits/sample.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.3
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• pp.14-26
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• 2012

In this paper, a fast diagonal-weighted Jacket matrices (DWJMs) is proposed to have the orthogonal architecture. We develop the successive DWJM to reduce the computational load while factorizing the large-order DWJMs into the low-order sparse matrices with the fast algorithms. The proposed DWJM is then applied to the precoding multiple-input and multiple output (MIMO) wireless communications because of its diagonal-weighted framework with element-wise inverse characteristics. Based on the properties of the DWJM, the DWJM can be used as alternative open loop cyclic delay diversity (CDD) precoding, which has recently become part of the cellular communications systems. Performance of the DWJM-based precoding system is verified for orthogonal space-time block code (OSTBC) MIMO LTE systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.5C
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• pp.276-285
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• 2011

In this paper, we propose new cooperative precoder selection technique for interference limited MIMO networks. Our proposed method gives weighting to precoders in the codebook according to each precoder's performance priority. By applying our proposed method to precoder selection sequence, performance of entire system can be improved in terms of sumrate, stability, and feedback rate.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.07a
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• pp.219-222
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• 2019

4차 산업혁명이 언급되면서 3D 프린터, 로봇, 인공지능, 빅데이터 등 신기술이 발전하고 이는 사회 구조를 변화시킬 것으로 예상된다. 이에 새로운 디지털 기기, 기술들을 이해하는 디지털 리터러시가 중요해지고 있다. 2015 OECD PISA에서 ICT 배경조사 중 한국은 접근성, 활용성 부분과 2018 국가수준 디지털 리터러시 수준 측정연구, 학생들의 디지털 기기의 인식 여부 및 활용 여부 실태조사를 바탕으로 디지털 기기 활용 공간 구성 및 디지털 기기 활용 콘텐츠를 다음과 같이 제안하였다. 먼저 구체적 조작기인 초등학생임을 고려하여 디지털 기기 위주 프로그램으로 선정하였다. 디지털 기기 활용 공간은 기반 기기로 컴퓨터(노트북), 유 무선 인터넷, 디지털 기기로 3D 프린터 및 3D 프린팅 펜, 스마트폰 기반 VR기기, AR마커, 블록코딩 기반 피지컬 컴퓨팅 교구 등을 이용해서 구성하였다. 활용하는 콘텐츠는 학생들의 인식 여부 및 수준에 맞춰 체험 위주의 프로그램과 학습, 콘텐츠 제작, 문제해결 프로그램으로 제시하였다.

• Journal of Broadcast Engineering
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• v.15 no.2
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• pp.157-162
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• 2010

In this paper, We propose that the adaptive cooperative relay transmission technique using closed-loop MIMO scheme for duplex communication system. As the mobility between relay and base station is little, closed-loop MIMO is better diversity gain than open-loop MIMO. At this time, more than one relaying terminals are included in one cooperative group to share their transmission and take precoding weight feedback. For minimization of throughput reduction caused by increasing feedback bits, we use codebook-based MRT that limit the number of feedback bits. Among the cooperative relay group, the best relays are selected from the base stataion and get the feedback. A protocol senarios are also proposed for this relay system.

• Journal of the Korea Society of Computer and Information
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• v.14 no.10
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• pp.63-71
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• 2009

In this study, we propose a revised dynamic ROI (Region-of-Interest) coding method in which the focused ROI is automatically extracted without help from users during the recovery process of low DOF (Depth-of-Field) JPEG2000 image. The proposed method creates edge mask information using high frequency sub-band data on a specific level in DWT (Discrete Wavelet Transform), and then identifies the edge code block for a high-speed ROI extraction. The algorithm scans the edge mask data in four directions by the unit of code block and identifies the edge code block simply and fastly using a edge threshold. As the results of experimentation applying for Implicit method, the proposed method showed the superiority in the side of speed and quality comparing to the existing methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.3C
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• pp.234-240
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• 2007

In this paper, low complexity block constrained trellis coded quantization (BC-TCQ) structures are introduced, and a predictive BC TCQ encoding method is developed for quantization of line spectrum frequencies (LSF) parameters for narrowband speech coding applications. Trellis-coded quantization(TCQ) is a form of VQ that builds the VQ codebook from interleaved constituent scalar quantization codebooks. The performance is compared to the other VQ, demonstrating reduction in spectral distortion and significant reduction in encoding complexity. The predictive BC-TCQ is about 0.47107 dB superior to the IS-641 split-VQ, 26bits/frame, in spectral distortion sense. The BC-TCQ is 64.54%, 76.93%, 2.35% of the IS-641 split-VQ, respectively, in the complexity of the additions, multiplies, comparisons.

• Korean Journal of Microbiology
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• v.55 no.1
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• pp.80-82
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• 2019

Pseudomonas syringae pv. syringae strain WSPS007 was isolated from infected twigs (Malus pumila) in 2013 in Yeongju, Gyeongbuk Province, Republic of Korea. Here, we report the draft genome sequence of WSPS007 with a chromosome size of 6,238,498 bp (59.04% G+C content). The genome comprises 5,379 CDS, 16 rRNA genes, and 65 tRNA genes. The P. syringae pv. syringae strain WSPS007 genome possesses an ice-nucleating activation (INA) gene and an antifreeze operon that may be related to frost damage by this pathogen. Thus, the genome sequence determined in this study will be useful in understanding the relationship between the outbreak of bacterial shoot blight disease and frost damage in northern Gyeongbuk Province.

• The Journal of the Acoustical Society of Korea
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• v.19 no.1
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• pp.97-102
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• 2000

Subband coding is to divide the signal frequency band into a set of uncorrelated frequency bands by filtering and then to encode each of these subbands using a bit allocation rationale matched to the signal energy in that subband. The actual coding of the subband signal can be done using waveform encoding techniques such as PCM, DPCM and vector quantizer(VQ) in order to obtain higher data compression. Most researchers have focused on the error in the quantizer, but not on the overall reconstruction error and its dependence on the filter bank. This paper provides a thorough analysis of subband codecs and further development of optimum filter bank design using vector quantizer. We compute the mean squared reconstruction error(MSE) which depends on N the number of entries in each code book, k the length of each code word, and on the filter bank coefficients. We form this MSE measure in terms of the equivalent quantization model and find the optimum FIR filter coefficients for each channel in the M-band structure for a given bit rate, given filter length, and given input signal correlation model. Specific design examples are worked out for 4-tap filter in 2-band paraunitary filter bank structure. These optimum paraunitary filter coefficients are obtained by using Monte Carlo simulation. We expect that the results of this work could be contributed to study on the optimum design of subband codecs using vector quantizer.