• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.6C
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• pp.465-474
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• 2005

In this paper, a directional reconstruction of lost block in image over noisy channel is presented. DCT coefficients or pixel values in the lost blocks are recovered by using the linear interpolation with available neighboring blocks that are adaptively selected by the directional measure that are composed of the DDC (Difference of DC opposite blocks)and SAC(Similarity of AC opposite blocks) between opposite blocks around lost blocks. The proposed directional recovery method is effective for the strong edge and texture regions because we do not make use of the fixed 4-neighboring blocks but exploit the varying neighboring blocks adaptively by the directional information in the local image. In this paper, we describe the novel directional measure(CDS: Combination of DDC and SAC) composed of the DDC and the SAC and select the usable block to recover the lost block with the directional measure. The proposed method shows about 0.6dB PSNR improvement in average compared to the conventional methods.

• BMB Reports
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• v.38 no.1
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• pp.49-57
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• 2005

Major Royal Jelly Protein cDNAs of Apis cerana (AcMRJP) were cloned and characterized. The open reading frames (ORFs) of the AcMRJP1 and AcMRJP2 genes were 1302 and 1392 nucleotides, encoding 433 and 463 amino acid residues, respectively. The sequence divergences between AcMRJP1 and AcMRJP2 and their corresponding protein families in A. mellifera were 0.0618 and 0.0934 at the nucleotide level and 0.0912 and 0.1438 at the protein level, respectively. Phylogenetic analysis supports the orthologous similarity between these proteins. The deduced amino acids indicated high essential amino acid contents of AcMRJP1 and AcMRJP2 (47.5 and 44.8%, respectively). The genomic organization of both AcMRJP1 and AcMRJP2 was determined. Both the AcMRJP1 (3663 bp) and AcMRJP2 (3963 bp) genes contained six exons and five introns, where all boundaries conformed to the GT/AG rule. AcMRJP1 and AcMRJP2 cDNAs were cloned into pET17b, and both the recombinant (r) AcMRJP1 (47.9 kDa) and rAcMRJP2 (51.7 kDa) were expressed in the insoluble form. Western blot analysis and N-terminal sequencing of the solubilized proteins revealed successful expression of rAcMRJP1 and rAcMRJP2 in vitro. The yields of the purified rAcMRJP1 and rAcMRJP2 were approximately 20 and 8mg protein per liter of the flask culture, respectively.

• The Plant Pathology Journal
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• v.37 no.1
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• pp.36-46
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• 2021

Acidovorax citrulli (Ac) is the causal agent of bacterial fruit blotch (BFB) in watermelon, a disease that poses a serious threat to watermelon production. Because of the lack of resistant cultivars against BFB, virulence factors or mechanisms need to be elucidated to control the disease. Glycerol-3-phosphate dehydrogenase is the enzyme involved in glycerol production from glucose during glycolysis. In this study, we report the functions of a putative glycerol-3-phosphate dehydrogenase in Ac (GlpdAc) using comparative proteomic analysis and phenotypic observation. A glpdAc knockout mutant, AcΔglpdAc(EV), lost virulence against watermelon in two pathogenicity tests. The putative 3D structure and amino acid sequence of GlpdAc showed high similarity with glycerol-3-phosphate dehydrogenases from other bacteria. Comparative proteomic analysis revealed that many proteins related to various metabolic pathways, including carbohydrate metabolism, were affected by GlpdAc. Although AcΔglpdAc(EV) could not use glucose as a sole carbon source, it showed growth in the presence of glycerol, indicating that GlpdAc is involved in glycolysis. AcΔglpdAc(EV) also displayed higher cell-to-cell aggregation than the wild-type bacteria, and tolerance to osmotic stress and ciprofloxacin was reduced and enhanced in the mutant, respectively. These results indicate that GlpdAc is involved in glycerol metabolism and other mechanisms, including virulence, demonstrating that the protein has pleiotropic effects. Our study expands the understanding of the functions of proteins associated with virulence in Ac.

• Advances in nano research
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• v.1 no.3
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• pp.171-182
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• 2013

The alternating current (AC) conductivity in semiconductor crystals with an open-core screw dislocation is studied in the current work. The screw dislocation in crystalline media results in an effective potential field which affects the electronic transport properties of the system. Therefore, from a technological view point, it is interesting to investigate properties of AC conductivity at frequencies of a few terahertz. To quantify the screw-induced potential effect, we calculated the AC conductivity of dislocated crystals using the Kubo formula. The conductivity showed peaks within the terahertz frequency region, where the amplitude of the AC conductivity was large enough to be measured in experiments. The measurable conductivity peaks did not arise in dislocation-free crystals threaded by a magnetic flux tube. These results imply different conductivity mechanisms in crystals with a screw dislocation than those threaded by a magnetic flux tube, despite the apparent similarity in their electronic eigenstates.

• Korean Journal of Breeding Science
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• v.43 no.5
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• pp.448-456
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• 2011

We used suppression subtractive hybridization (SSH) combined with mirror orientation selection (MOS) method to screen differentially expressed genes from red-fleshed kiwifruit 'Hongyang'. As a result, the 288 clones were obtained by subcloning PCR product and 192 clones that showed positive clones on colony PCR analysis were selected. All the positive clones were sequenced. After comparisons with the NCBI/Genbank database using the BLAST search revealed that 30 clones showed sequence similarity to genes from other organisms; 10 clones showed significant sequence similarity to known genes. Among these clones, 3 clones (AcF21, AcF42 and AcF106) had sequence homology to 1-aminicyclopropane-carboxylic acid (ACC)-oxidase (ACO) that known to be related to fruit ripening. The expression patterns of differentially expressed genes were further investigated to validate the SSH data by reverse transcription PCR (RT-PCR) and quantitative real-time PCR (qReal-time PCR) analysis. All the data from qReal-time PCR analysis coincide with the results obtained from RT-PCR analysis. Three clones were expressed at higher levels in 'Hongyang' than 'Hayward'. AcF21 was highly expressed in the other genes at 120 days after full bloom (DAFB) and 160 DAFB of 'Hongyang'.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.1
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• pp.13-21
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• 2019

The content based on image retrieval makes use of features of information within image such as color, texture and share for Retrieval data. we present a novel approach for improving retrieval accuracy based on DCT Filter-Bank. First, we perform DCT on a given image, and generate a Filter-Bank using the DCT coefficients for each color channel. In this step, DC and the limited number of AC coefficients are used. Next, a feature vector is obtained from the histogram of the quantized DC coefficients. Then, AC coefficients in the Filter-Bank are separated into three main groups indicating horizontal, vertical, and diagonal edge directions, respectively, according to their spatial-frequency properties. Each directional group creates its histogram after employing Otsu binarization technique. Finally, we project each histogram on the horizontal and vertical axes, and generate a feature vector for each group. The computed DC and AC feature vectors bins are concatenated, and it is used in the similarity checking procedure. We experimented using 1,000 databases, and as a result, this approach outperformed the old retrieval method which used color information.

• Parasites, Hosts and Diseases
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• v.49 no.2
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• pp.103-108
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• 2011

Autophagy is a catabolic process involved in the degradation of a cell's own components for cell growth, development, homeostasis, and the recycling of cellular products. Autophagosome is an essential component in the protozoan parasite during differentiation and encystation. The present study identified and characterized autophagy-related protein (Atg) 3, a member of Atg8 conjugation system, in Acanthamoeba castellanii (AcAtg3). AcAtg3 encoding a 304 amino acid protein showed high similarity with the catalytic cysteine site of other E2 like enzymes of ubiquitin system. Predicted 3D structure of AcAtg3 revealed a hammer-like shape, which is the characteristic structure of E2-like enzymes. The expression level of AcAtg3 did not increase during encystation. However, the formation of mature cysts was significantly reduced in Atg3-siRNA transfected cells in which the production of Atg8-phosphatidylethanolamine conjugate was inhibited. Fluorescent microscopic analysis revealed that dispersed AcAtg3-EGFP fusion protein gathered around autophagosomal membranes during encystation. These results provide important information for understanding autophagic machinery through the lipidation reaction mediated by Atg3 in Acanthamoeba.

• The Transactions of the Korea Information Processing Society
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• v.4 no.1
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• pp.11-22
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• 1997

The fractal image compression partitions an original image into blocks of equal size and searches a do-main block having self-similarity. This method of compression achieves high compression ratio because it is unnecessary to transmit the additional codebook to receiver and it provides good quality of reconstructed images. In spite of these advantages, this method has a drawback in which encoding time increase due to a complicated linear transformation for determining a similar-domain block. In this paper, a fast fractal image compression method is proposed by decreasing the number of transformation usings AC(alternating current) coefficients of block. The proposed method also has a good quality as compared with the well-known fractal codings. Furthermore, method also has a good quality as apply the video steganography that can conceal an important secret data.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2017.06a
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• pp.81-82
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• 2017

본 논문에서는 PSNR 을 높이도록 최적화된 HEVC 의 율-왜곡 최적화(RDO)를 MS-SSIM 를 높이도록 하여 RDO 를 수행 하도록 한다. 구현 방법으로는 MS-SSIM 도출 방법과 비슷하도록 원본과 4 단계의 저역 통과 필터(LPF)를 통과한 결과에 대한 DCT(Discrete Cosine Transform) 를 수행하고 그 AC 계수의 비율로 lagrange multiplier(${\lambda}$)를 수정하는 방식이다. AC 계수 비율과 MS-SSIM 에서 도출 된 가중치, LPF 특성 등에 따라 새롭게 각 스케일의 가중치를 결정하여 최종적으로 ${\lambda}$ 가중치를 결정하여 그 결과를 바탕으로 RDO 를 수행한다. 시뮬레이션을 통해 제안의 방법과 HEVC reference software 의 BD-rate 계산 결과 7%의 PNSR, -13.2%의 MS-SSIM 를 얻을 수 있었고 이에 따라 주관적 화질을 개선했다고 할 수 있다.

• Korean Journal of Veterinary Research
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• v.46 no.3
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• pp.235-248
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• 2006

The VP2 full gene of Korean infectious bursal disease virus(IBDV) strain, SH/92, three attenuated vaccine strains, Bur706, Bursine-2 and CEV/AC strains, were amplified by reverse transcriptase-polymerase chain reaction and sequenced and compared with published VP2 gene sequences of IBDVs. The VP2 nucleotide sequence similarity between SH/92 and three vaccine stains was 95.6~96.5% whereas the nucleic acid similarity among three vaccine strains was 97.5~98.5%. The amino acid sequence similarity of VP2 of SH/92 compared with three vaccine strains was between 94.4 and 97.6% while the amino acid similarity among three vaccine strains was between 97.4 and 98.4%. The amino acid similarity between SH/92 and classical virulent strain, 52/70 and STC strain was 96.4 and 96.5%, respectively. The serine-rich heptapeptide was conserved in CEVAC and Bursine-2 as well as SH/92 but not in Bur706. The phylogenetic tree developed from amino acid sequences showed that SH/92 was categorized with vv IBDVs(HK46, OKYM, KKI, UPM94/273, SH95) in one branch while three vaccine strains were catagorized with STC strain in the other branch.