• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.9
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• pp.1293-1298
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• 2013

This paper proposes a noise reduction algorithm using Wiener filter to remove the noise components from the noisy speech in order to improve the speech signal. The proposed algorithm first removes the noise spectrums of white noise from the noisy signal based on the noise reshaping and reduction method at each frame. And this algorithm enhances the speech signal using Wiener filter based on linear predictive coding analysis. In this experiment, experimental results of the proposed algorithm demonstrate using the speech and noise data by Japanese male speaker. Based on measuring the spectral distortion (SD) measure, experiments confirm that the proposed algorithm is effective for the speech by contaminated white noise. From the experiments, the maximum improvement in the output SD values was 4.94 dB better for white noise compared with former Wiener filter.

• The Journal of the Acoustical Society of Korea
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• v.20 no.4
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• pp.29-34
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• 2001

In this paper, we designed an LSF coefficient quantizer of the wideband speech codec that can produce high quality speech service. For the efficient LSF coefficient quantizer, the interframe correlation was used. Also we separately quantized the LSF coefficients with high and low interframe correlation. Predictive pyramid vector quantizer (PVQ) was used for quantizing the LSF coefficients with high interframe correlation, and PVQ was used for quantizing the LSF coefficients with low interframe correlation. Experiments show that the proposed UF quantizer can quantize LSF information in 40 bits/frame, with an average spectral distortion (SD) of 1 dB and less than 3.87% frames having SD greater than 2 dB.

• Journal of Microbiology and Biotechnology
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• v.9 no.5
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• pp.582-588
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• 1999

A Brevibacterium lactofermentum gene coding for a glucose-specific permease of the phosphoenolpyruvate-dependent phosphotransferase system (PTS) was cloned, by complementing an Escherichia coli mutation affecting a ptsG gene with the B. lactofermentum genomic library, and completely sequenced. The gene was identified as a ptsG, which enables an E. coli transformant to transport non-metabolizable glucose analogue 2-deoxyglucose (2DG). The ptsG gene of B. lactofermentum consists of an open reading frame of 2,025 nucleotides encoding a polypeptide of 674 amino acid residues and a TAA stop codon. The 3' flanking region contains two stem-loop structures which may be involved in transcriptional termination. The deduced amino acid sequence of the B. lactofermentum enzyme $II^{GIe}$ specific to glucose ($EII^{GIe}$) has a high homology with the Corynebacterium glutamicum enzyme $II^{Man}$ specific to glucose and mannose ($EII^{Man}$), and the Brevibacterium ammoniagenes enzyme $II^{GIc}$ specific to glucose ($EII^{GIc}$). The 171-amino-acid C-terminal sequence of the $EII^{Glc}$ is also similar to the Escherichia coli enzyme $IIA^{GIc}$ specific to glucose ($IIA^{GIc}$). It is interesting that the arrangement of the structural domains, IIBCA, of the B. lactofermentum $EII^{GIc}$ protein is identical to that of EIIs specific to sucrose or $\beta$-glucoside. Several in vivo complementation studies indicated that the B. lactofermentum $EII^{Glc}$ protein could replace both $EII^{ Glc}$ and $EIIA^{Glc}$ in an E. coli ptsG mutant or crr mutant, respectively.

• Journal of Broadcast Engineering
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• v.15 no.1
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• pp.52-62
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• 2010

Recently, DVC (Distributed Video Coding) is attracting a lot of research works since this enables us to implement a light-weight video encoder by distributing the high complex tasks such as motion estimation into the decoder side. In order to improve the coding efficiency of the DVC, the existing works have been focused on the efficient generation of side information (SI) or the virtual channel modeling which can describe the statistical channel noise well. But, in order to improve the overall performance, this paper proposes a new scheme that can be implemented with simple bit operations without introducing complex operation. That is, the performance of the proposed scheme is enhanced by using the fact that the Wyner-Ziv (WZ) frame and side information are highly correlated, and by reducing the effect of virtual channel noise which tends to be clustered in some regions. For this aim, this paper proposes an efficient pixel-domain WZ (PDWZ) CODEC which effectively exploits the statistical redundancy by using the code conversion and Gray code, and then reduces the channel noise by using the bit interleaver. Through computer simulations, it is shown that the proposed scheme can improve the performance up to 0.5 dB in objective visual quality.

• Journal of Microbiology and Biotechnology
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• v.8 no.3
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• pp.214-221
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• 1998

A Brevibacterium ammoniagenes gene coding for glucose/mannose-specific enzyme II ($EII^{Glc}$) of the phosphoenolpyruvate-dependent phosphotransferase system (PTS) was cloned by complementing an Escherichia coli mutation affecting a ptsG gene, and the complete DNA nucleotide sequence was determined. The cloned gene was identified to be a ptsG, which enables the E. coli transportment to use glucose more efficiently than mannose as the sole carbon source in an M9 minimal medium. The ptsG gene of B. ammoniagenes consists of an open reading frame of 1,983 nucleotides putatively encoding a polypeptide of 661 amino acid residues and a TAA stop codon. The deduced amino acid sequence of the B. ammoniagenes $EII^{Glc}$ shows, at $46\%$, the highest degree of sequence similarity with the Corynebacterium glutamicum EII specific for both glucose and mannose. In addition, the $EII^{Glc}$ shares approximately $30\%$ sequence similarities with sucrose-specific and ${\beta}$-glucoside-specific EIIs of the several bacteria belonging to the glucose-PTS class. The 161-amino-acid C-terminal sequence of $EII^{Glc}$ is also similar to that of E. coli enzyme $IIA^{Glc}$, specific for glucose ($EIIA^{Glc}$). The B. ammoniagenes $EII^{Glc}$ consists of three domains; a hydrophobic region (EIIC) and two hydrophilic regions (EIIA, EIIB). The arrangement of structural domains, IIBCA, of the $EII^{Glc}$ is identical to those of EIIs specific for sucrose or ${\beta}$-glucoside. While the domain IIA was removed from the B. ammoniagenes $EII^{Glc}$ the remaining domains IIBC were found to restore the glucose and mannose-utilizing capacity of E. coli mutant lacking $EII^{Glc}$ activity with $EIIA^{Glc}$ of the E. coli mutant. $EII^{Glc}$ contains a histidine residue and a cysteine residue which are putative phosphorylation sites for the protein.

• Journal of Broadcast Engineering
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• v.9 no.3
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• pp.196-206
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• 2004

This paper presents an efficient joint disparity-motion estimation algorithm for stereo sequence CODEC. Disparity vectors are estimated by the left and right motion vectors and previous disparity vectors for every frame. In order to obtain more accurate disparity vectors. we include a spatial prediction Process after the feint estimation. From joint estimation and spatial prediction, we can obtain accurate disparity vectors and then Increase coding efficiency. Finally, we proposed the backward quadtree decomposition. which helps the encoder to have a more detailed disparity vector map without transmitting additional coding bits for quadtree information. We confirmed superior performance of the proposed method through computer simulation.

• Journal of Broadcast Engineering
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• v.22 no.2
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• pp.193-206
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• 2017

In this paper, we propose a rate control method based on the $R-{\lambda}$ model that supports a parallel encoding structure in GOP levels or IDR period levels for 4K UHD input video in real-time. For this, a slice-level bit allocation method is proposed for parallel encoding instead of sequential encoding. When a rate control algorithm is applied in the GOP level or IDR period level parallelism, the information of how many bits are consumed cannot be shared among the frames belonging to a same frame level except the lowest frame level of the hierarchical B structure. Therefore, it is impossible to manage the bit budget with the existing bit allocation method. In order to solve this problem, we improve the bit allocation procedure of the conventional ones that allocate target bits sequentially according to the encoding order. That is, the proposed bit allocation strategy is to assign the target bits in GOPs first, then to distribute the assigned target bits from the lowest depth level to the highest depth level of the HEVC hierarchical B structure within each GOP. In addition, we proposed a processing method that is used to improve subjective image qualities by allocating the bits according to the coding complexities of the frames. Experimental results show that the proposed bit allocation method works well for frame-level parallel HEVC software encoders and it is confirmed that the performance of our rate controller can be improved with a more elaborate bit allocation strategy by using the preprocessing results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.9C
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• pp.849-860
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• 2007

Because the H.264/AVC standard adopts the variable length coding algorithm, the rate of encoded video bitstream fluctuates a lot as time flows, though its compression efficiency is superior to that of existing standards. When a video is transmitted in real-time over networks with fixed low-bandwidth, it is necessary to control the bit rate which is generated from encoder. Many existing rate control algorithms have been adopting the quadratic rate-distortion model which determines the target bits for each frame. We propose a new rate control algorithm for H.264/AVC video transmission over networks with fixed bandwidth. The proposed algorithm predicts quantization parameter adaptively to reduce video distortion using the quadratic rate-distortion model, which uses the target bit rate and the mean absolute difference for current frame considering pixel difference between macroblocks in the previous and the current frame. On video samples with high motion and scene change cases, experimental results show that (1) the proposed algorithm adapts the encoded bitstream to limited channel capacity, while existing algorithms abruptly excess the limit bit rate; (2) the proposed algorithm improves picture quality with $0.4{\sim}0.9dB$ in average.

• Microbiology and Biotechnology Letters
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• v.28 no.3
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• pp.147-151
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• 2000

School of Food Biotechnology, W0050ng University, San 7-6, Jayang~dong. Dong-ku1 Taejon 300-100, Korea - The nucleotide sequence of approximately 2.4 kb immediately adjacent to ptsG gene coding for the glucose permease of Brevibacterium ammoniagenes was detennined. A putative open reading frame (ORP) of 1.467 nucleotides encoding a polypeptide of 489 amino acid residues and a TAA stop codon was identified. The deduced amino acid sequence of the ORF product has a high homology with the 30S ribosomal protein S 1 of Mycohacteriwn tuberculosis (83 % ). M leprae (74%), Streptomyces coelicola (77%), and Escherichia coli (40%). suggesting that the predicted product of ORF is a ribosomal protein S 1. The ORF is located at a distance of 266 nucleotides upstream from ptsC gene with a same translational direction.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.3B
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• pp.264-273
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• 2009

For IEEE 802.15.3 HR-WPAN, we propose the DABL algorithm that PNC can allocate the channel times to the DEV in super frame in order that system frame throughput is increased and the delay is decreased. In detail, the DABL algorithm allows to dynamically allocate channel time as well as to adaptively apply the modulation and coding scheme based on the link quality of the DEV. In addition, due to the facts that QoS is quite different depending on service types, we provide the DABL algorithm taking into account RT(Real Time) traffic and Non-RT traffic respectively. Finally, we show simulation results of the DABL algorithm compared to the conventional algorithm that the PNC equally allocates channel times to the DEV regardless of the link quality of the DEV.