• 한국멀티미디어학회논문지
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• 제7권6호
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• pp.791-797
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• 2004

We proposed a novel digital video watermarking that embeds dual watermarks in the block DCT domain to solve the deadlock problem. Daul watermarks are composed of private watermarks and robust blind watermarks. Firstly, private watermarks are embedded into the lowest AC coefficients of the P or B-frames in accordance with the motion direction gained from a previous frame. Secondly, blind watermarks that have the robustness are inserted into the DC coefficients of the I-frames using a private key made from temporal I-frame motion information. Thus, when a deadlock situation occurs, the proposed algorithm can efficiently solve the problem. Experimental results confirmed that the proposed algorithm can produce good subjective and objective results for MPEG coding with a variety of bit rates. Furthermore, the proposed watermarking algorithm can potentially be applied to broadcasting monitoring systems due to its simplicity and high robustness.

• Journal of Electrical Engineering and Technology
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• 제11권2호
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• pp.519-528
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• 2016

In order to achieve fast computational speed with good visual quality of output video, we propose a frequency domain based new fractal video compression scheme. Normalized cross correlation is used to find the structural self similar domain block for the input range block. To increase the searching speed, cross correlation is implemented in the frequency domain using FFT with one computational operation for all the domain blocks instead of individual block wise calculations. The encoding time is further minimized by applying rotation and reflection DFT properties to the IFFT of zero padded range blocks. The energy of overlap small size domain blocks is pre-computed for the entire reference frame and retaining the energies of the overlapped search window portion of previous adjacent block. Quadtree decompositions are obtained by using domain block motion compensated prediction error as a threshold to control the further partitions of the block. It provides a better level of adaption to the scene contents than fixed block size approach. The result shows that, on average, the proposed method can raise the encoding speed by 48.8 % and 90 % higher than NHEXS and CPM/NCIM algorithms respectively. The compression ratio and PSNR of the proposed method is increased by 15.41 and 0.89 dB higher than that of NHEXS on average. For low bit rate videos, the proposed algorithm achieve the high compression ratio above 120 with more than 31 dB PSNR.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1996년도 식물학심포지움 식물호르몬과 신호전달
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• pp.68-78
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• 1996

Two types of immunoloigcal probes, anti-ABBP Abs, have been developed. The purified ABBP from ABA-C1-BSA-sepharose 4B column was identified by PAGE and appeared in one band of about 56KD, as well as showed a specific binding ability and a high affinity for ABA (Kd2.0$\times$10-9 mol/L). Unexpectedly, the existence of rRNA with a length of around 300 nucleotides could be found, when the ABBP was digested with proteinase K and identified by eletrophorsis on an agarose gel (1%). As a result, about 120 cDNA clones coding maize 17s RNA and only one cDNA clone coding ABBP (24cDNA) were obtained from 200,000 seperated phage plaques by the anti-ABBP pAbs. 24cDNA had 1075bp and contained an open reading frame coding 254 amino acids. The anti-idiotypic Ab raised against an ABA MAb showed the ability of either mimicking ABA or competing with ABA. The localization of ABBPs in plant cell was investigated.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.887-890
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• 1998

We present a novel multi-resolution block matching algorithm (BMA) for fast motion estimation. At the coarsest level, a full search BMA (FSBMA) is performed for searching complex or random motion. Concurrently, spatial correlation of motion vector (MV) field is used for searching continuous motion. Here we present an efficient method for searching full resolution MVs without MV decimation even at the coarsest leve. After the coarsest level search, two or three initial MV candidates are chosen for the next level. At the further levels, the MV candidates are refined within much smaller search areas. Simulation results show that in comparison with FSBMA, the proposed BMA achieves a speed-up factor over 710 with minor PSNR degradation of 0.2dB at most, under a normal MPEG2 coding environment. Furthermore, our scheme is also suitable for hardware implementation due to regular data-flow.

• 한국약용작물학회지
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• 제10권4호
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• pp.294-297
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• 2002

A gene coding for the GST of cotton (Gh-5) was cloned into Escherichia coli and experssed. The enzyme remained within the cytoplasm of E. coli. An 696 bp open reading frame was in the 988 base pair fragment of the recombinant plasmid pET-30b(+). The deduced protein sequence consists of 232 amino acids and has a molecular mass of 30235.58 Da. The cloned enzyme conjugated reduced glutathione and 1-chloro-2,4-dinitrobenzene (CDNB). Plant GST cDNA was expressed in microbe and produced polypeptide had function as an enzyme.

• 한국통신학회논문지
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• 제21권5호
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• pp.1096-1108
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• 1996

In this paper, we propose a temporal adaptive tranform 3D SBC coder with motion compensation, exploiting redundancy in the temporal domain. We propose a temporal adaptivity measure, by which the R-D optimal temporal transform can be chaosen. The base temporal subband frame is coded using H.261-like MC-DCT coder, while the higher temporal subband frames are coded using the 2D adaptive wavelet packet bases, considering the various energy distribution which results from the temporal variation. In encoding the subbands, we employ adaptive scanning methods, uniform step-size quantization with VLC, and coded/not-coded flag reduction technique using the quadtree structure. From the simulation results, the proposed adaptive 3D subband coder shows about 0.29~3.14 dB gain over the H.261 and the fixed 3D subband coder techniques.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.257-258
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• 2007

In real-time video communications, the large fluctuation of bits generated from contiguous frames may lead to the buffer oveflow and the delay of transmitting video data. This paper proposes a method that the bits generated from each frame may be in the range of specified fluctuation. The method uses a scene change detector and ignores the time information of detected frames. The experimental results indicate that our scheme achieves average PSNR gain of 2.0dB over TMN8.

• 한국통신학회논문지
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• 제31권5C호
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• pp.490-496
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• 2006

H.264는 현재 IP를 기반으로 하는 유무선 네트워크분야에서 많은 관심을 받고 있는 표준으로서 기존에 제정된 비디오 표준들보다 향상된 에러 복구 기술들을 포함하고 있다. 본 논문에서는 기존의 비디오 표준에서 사용되어 오던 raster scan 방식과 H.264의 에러 복구 기술들 중 하나인 FMO (flexible macroblock ordering) 방식에 에러 은닉 기술을 적용하여 에러 은닉의 성능이 정확히 온 인접한 매크로블락 수에 따라 좌우됨을 분석하고, 다양한 패킷 손실율에서의 성능을 보인다. 시뮬레이션 결과, FMO 방식이 raster scan 방식에 비해 손실없이 오는 인접한 매크로블락 수가 많아 에러 은닉에 의한 PSNR 성능이 $1{\sim}9dB$ 정도 향상되고, 특히 인트라 프레임 간격이 길고 패킷 손실율이 높은 경우에 FMO 방식에 의한 PSNR 성능 향상이 더 크다.

• 정보통신설비학회논문지
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• 제2권2호
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• pp.36-45
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• 2003

본 논문은 무선 멀티미디어용 OFDM 시스템에 적용 할 수 있는 송신다이버시티 기술로 전송 효율 및 수신성능을 최대로 하기 위한 방안을 제시한다. 제안된 방법은 MIMO 채널에 적합한 시공간 부호기법으로 STTC(Space-Time Trellis Code)의 성능 분석을 위해 두 가지의 rms 지연확산, 즉 50 nsec, 150 nsec를 고려한 채널 추정에서 시평균을 위한 파라미터 $\alpha$가 0.3, 1인 경우와 하나의 프레임내에서 긴 훈련열 구간으로부터 추정된 채널 값을 해당 프레임에 적용한 경우의 성능을 비교 분석하였다. 실험결과 $\alpha$가 0.3인 경우가 긴 훈련 열만을 이용한 경우보다 BER이 $10^{-3}$에서 1.0dB의 SNR 개선을 가져옴을 알 수 있었으며, 또한 시평균을 위한 것이 그렇지 않은 경우보다 전반적인 성능 개선이 향상된다는 것을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제8권1호
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• pp.28-33
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• 1998

A gene coding for ${\beta}$-xylosidase from thermophilic xylanolytic Bacillus sp. KK-1 was cloned into Escherichia coli using plasmid pBR322. Recombinant plasmid DNAs were isloated from E. coli clones which were capable of hydrolyzing 4-methylumbelliferyl-${\beta}$-D xylopyranoside. Restriction analysis showed the DNAs to share a common insert DNA. Xylo-oligosaccharides, including xylotriose, xylotetraose, xylopentaose, and xylobiose were hydrolyzed to form xylose as an end product by cell-free extracts of the E. coli clones, confirming that the cloned gene from strain KK-1 is ${\beta}$-xylosidase gene. The ${\beta}$-xylosidase gene of strain KK-1 designated as xylB was completely sequenced. The xylB gene consisted of an open reading frame of 1,602 nucleotides encoding a polypeptide of 533 amino acid residues, and a TGA stop codon. The 3' flanking region contained one stem-loop structure which may be involved in transcriptional termination. The deduced amino acid sequence of the KK-1 ${\beta}$-xylosidase was highly homologous to the ${\beta}$-xylosidases of Bacillus subtilis and Bacillus pumilus, but it showed no similarity to a thermostable ${\beta}$-xylosidase from Bacillus stearothermophilus.