• Proceedings of the Korean Society of Broadcast Engineers Conference
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• fall
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• pp.45-48
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• 2021

본 논문은 RGB 컬러 3 채널에 대해 공유되는 홀로그램 픽셀 피치를 사용하여 3 차원 장면의 라이트 필드 데이터에서 비호겔 기반 컴퓨터 생성 홀로그램(CGH)을 합성하는 방법을 제안한다. 비호겔 기반 CGH 기술은 라이트 필드의 광선 각도를 평면 파면의 공간 주파수로 해석하여 주어진 라이트 필드 데이터에서 임의의 반송파로 연속 파면을 생성한다. 그러나 광선 각도와 공간 주파수 관계는 파장에 따라 달라지므로 라이트 필드 데이터에서 공간 주파수 샘플링 그리드가 달라져서 홀로그램 재구성에서 색 수차가 발생한다. 제안하는 방법은 가장 작은 청색 회절각이 라이트 필드의 시야를 커버하도록 모든 색상 채널에 공통적인 홀로그램 픽셀 피치를 설정한다. 그런 다음 라이트 필드를 파란색 파장의 공간 주파수 범위와 빨간색 파장의 샘플링 간격으로 보간하여 모든 색상 채널에 공통적인 공간 주파수 샘플링 그리드를 설정한다. 공통 홀로그램 픽셀 피치 및 라이트 필드 공간 주파수 샘플링 그리드는 홀로그램 재구성에서 색상 수차 또는 라이트 필드에 포함된 정보 손실 없이 컬러 홀로그램 합성을 보장한다. 제안된 방법은 다양한 테스트와 리얼 3D 장면의 컬러 라이트 필드 데이터를 사용하여 검증되었다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• fall
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• pp.235-237
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• 2021

코로나 19로 대학교 강의들이 비대면 방식으로 전환되고 있는데, 기존의 교수학습 지원센터는 웹 환경만을 제공한다. 따라서 본 논문에서는 모바일 애플리케이션을 통해 수강생들이 교수학습 지원센터에 쉽게 접근할 수 있도록 도와주는 시스템을 개발하였다. 애플리케이션에서 학생들의 강의 시간 및 시험, 과제 등의 일정을 관리해주고, 푸시 알림을 제공해주는 학습 도우미의 역할을 수행한다. 뿐만 아니라 직관적인 인터페이스, 다크 모드, scroll-to-top 버튼 등을 고려한 디자인으로 사용자의 편리함을 도모한다. 학습 도우미 애플리케이션의 가장 핵심기능 중 하나는 머신러닝 기법 중 비선형 회귀(Non-Linear Regression)을 이용해 성적 데이터를 분석해주는 차별화된 기능이다. 이를 위해 최종적인 성적을 종속변수, 일정 기간까지의 성적을 독립변수로 설정하여 기존의 성적 데이터를 바탕으로 종속변수인 최종성적을 랜덤 포레스트 비선형 회귀분석으로 예측하는 알고리즘을 제시하고자 한다.

• KSBB Journal
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• v.19 no.5
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• pp.363-367
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• 2004

Leuconostoc mesenteroides NRRL B-1149 produces various glucoseyltransferases for the synthesis of dextran, levan and glucose-1-phosphate using sucrose as a substrate. A sucrose phosphorylase (1149SPase) was purified from L. mesenteroides NRRL B-1149 culture by using hollow fiber filtration (30 kDa cut off), Toyopearl DEAE 650 M column chromatography and following two times of DEAE-Sepharose column chromatographies. The specific activity of the purified 1149SPase was 25.7 (U/mg) with $16\%$ yield. The 1149SPase showed a molecular size of 56 kDa on denatured $10\%$ SDS-PAGE. The N-terminal amino acid sequence of the enzyme was MEIQNKAM. The optimum pH and temperature of this enzyme were 6.2~6.5 and 37^{circ}C, respectively. It had an apparent K_{m} of 6.0 mM and K_{cat} of 1.62/s for sucrose. 1149SPase crystal was formed by hanging drop diffusion technique using 20 mM calcium chloride dihydrate, 100 mM sodium acetate trihydrate pH 4.6 and $30\%$ 2-methyl-2,4-pentanediol as vaporizing and reservation solution. The 1149SPase catalyzes transferring of glucose from isomaltose or sucrose to salicin and salicyl alcohol by disproportionation reaction or acceptor reaction and synthesized two acceptor products, respectively.

• BMB Reports
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• v.32 no.3
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• pp.299-305
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• 1999

Protein carboxyl O-methyltransferase (PCMT) catalyzes the transfer of a methyl group from Sadenosyl-L-methionine to free carboxyl groups of methyl-accepting substrate proteins. Two isozymes were separated by DEAE-Sephacel chromatography from porcine brain cytosol and designated PCMT I and II. Isozymes I and II were further purified by adenosyl homocysteine-Sepharose 4B and Superose HR 12 chromatography. The molecular weights of the purified PCMT I and II were determined by mass spectrometry to be 20,138 Da and 25,574 Da, respectively. The two enzymes displayed different isoelectric points; 7.9 for PCMT I and 5.3 for PCMT II. Isozymes I and II exhibited similar substrate specificities when tested with various methyl-accepting proteins. Myelin basic protein, a component of myelinated neurons, was found to be an excellent methyl-accepting substrate for both PCMT isozymes with different $K_m$ values, $21.1\;{\mu}M$ for PCMT I and $10.6\;{\mu}M$ for PCMT II. The PCMT activity and methyl-accepting capacity displayed similar distribution in the various brain regions with an exception of the lower values in the cerebellum. The overall distribution may relate to a general function of protein repair by PCMT in the brain.

• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.537-543
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• 2003

The mouse interferon gene (MuIFN-${\gamma}$) was cloned and then used to transform Saccharomyces cerevisiae. Expressed MuIFN-$\{gamma}$ protein (MuIFN-${\gamma}$) was successfully secreted into culture medium due to the presence oi the signal peptide of rice amylase 1A. Two different promoters fused to MuIFN-${\gamma}$ were tested: glyceraldehyde-3-phosphate dehydrogenase (GPD) promoter and a yeast hybrid ADH2-GPD (AG) promoter consisting of alcohol dehydrogenase II (ADH2) and GPD promoter. Using the hybrid promoter, the accumulation of MuIFN-${\gamma}$transcript was the highest after the 24 h cultivation, and then gradually decreased as the cultivation proceeded. However, both cell growth and recombinant MuIFN-${\gamma}$production reached their peaks after the 4-day cultivation. It was possible to produce 6.5 mg/l of MuIFN-${\gamma}$ without any changes in cell growth. Using GPD promoter, the MuIFN-${\gamma}$ transcript accumulation and the recombinant MuIFN-${\gamma}$ production followed the same pattern as the cell growth. However. compared to that of the hybrid promoter, the production of recombinant MuIFN-${\gamma}$ was 0.2 mg/l. The secreted MuIFN-${\gamma}$ had estimated molecular masses of 21 kDa and 23 kDa, which were larger than that of the encoded size due to glycosylation. The protection assay against the viral infection indicated that the recombinant MuIFN-${\gamma}$ was bioactive.

• Reproductive and Developmental Biology
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• v.33 no.2
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• pp.93-98
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• 2009

In this study, bovine Dnmt1 cDNA was sequenced and detected Dnmt1 mRNA level in bovine tissues by northern blot, methylation pattern of genome by southern blot, specific localization of Dnmt1 in mouse and bovine preimplantation embryos by immunocytostaining and Dnmt1 protein level in ovary and testis by western blot. Bovine Dnmt1 cDNA sequence showed more homology with that of human than mouse and rat. The RNA level of Dnmt1 was 10 times higher expression in placenta than other tissues. This indicates that placenta was hypermethylated compared to others organs. The genomic DNA could not be cut by a specific restriction enzyme (HpaII) in placenta, lung and liver of bovine. It suggests that Dnmt1 in some somatic cells was already methylated. Dnmt1, which has the antibody epitope 1316~1616, was distributed in nucleus and cytoplasm including the stage of pronuclear stage and maturation of oocyte and gradually weaken to blastocyst stage compare to negative. In addition, Dnmt1 was strongly expressed in tetraploid embryo and cloned 8-cell than IVF 8-cell. An aberrant pattern of DNA methylation in cloned embryo may be abnormal development of fetus, embryonic lethality and placenta dysfunction. The somatic specific band (190kDa) was appeared in ovary and testis, but oocyte specific band (175kDa) was not. Further investigations are necessary to understand the complex links between the methyltransferases and the transcriptional activity of genes in the cloned bovine tissues.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.921-926
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• 2006

The production and location of xylanolytic enzymes in alkaliphilic Bacillus sp. K-1, isolated from the wastewater treatment plant of the pulp and paper industry, was studied. When grown in alkaline xylan medium, the bacteria produced xylanolytic enzymes such as xylanase, $\beta$-xylosidase, arabinofuranosidase, and acetyl esterase. Two types of xylanases (23 and 45 kDa) were found to be extracellular, but another type of xylanase (35 and/or 40 kDa) was detected as pellet-bound that was eluted with 2% triethylamine from the residual xylan of the culture. The xylanases were different in their molecular weight and xylan-binding ability. Arabinofuranosidase and $\beta$-xylosidase were found to be intracellular and extracellular, respectively, and acetyl esterase was found to be extracellular. The extracellular xylanolytic enzymes effectively hydrolyzed insoluble xylan, lignocellulosic materials, and xylans in kraft pulps.

• Journal of the Korean Magnetic Resonance Society
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• v.15 no.2
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• pp.137-145
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• 2011

Hsp33, a prokaryotic molecular chaperone, exerts holdase activity in response to oxidative stress. In this study, the stepwise conformational change of Hsp33 upon oxidation was monitored by NMR. In order to overcome its high molecular weight (33 kDa as a monomer and 66 kDa as a dimer), spectra were simplified using a selectively [$^{15}N$]His-labeled protein. All of the eight histidines were observed in the TROSY spectrum of the reduced Hsp33. Among them, three peaks showed dramatic resonance shifts dependent on the stepwise oxidation, indicating a remarkable conformational change. The results suggest that unfolding of the linker domain is associated with dimerization, but not entire region of the linker domain is unfolded.

• Journal of Microbiology and Biotechnology
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• v.22 no.11
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• pp.1580-1587
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• 2012

Japanese encephalitis virus (JEV) envelope (E) protein holds great promise for use in the development of a recombinant vaccine. Purified recombinant E (rE) protein may be useful for numerous clinical applications; however, there are limitations in using the Escherichia coli expression system for producing high-quality rE protein. Therefore, in this study, the yeast expression system was used to generate the rE protein. For protein production using the yeast system, the full-length JEV E gene was cloned into Pichia pastoris. SDS-PAGE and immunoblotting analysis demonstrated that the rE protein had a molecular mass of 58 kDa and was glycosylated. The predicted size of the mature unmodified E protein is 53 kDa, suggesting that post-translational modifications resulted in the higher molecular mass. The rE protein was purified to greater than 95% purity using combined ammonium sulfate precipitation and a SP-Sepharose Fast Flow column. This purified rE protein was evaluated for immunogenicity and protective efficacy in mice. The survival rates of mice immunized with the rE protein were significantly increased over that of Hyphantria cunea nuclear polyhedrosis virus E protein (HcE). Our results indicate that the rE protein expressed in the P. pastoris expression system holds great promise for use in the development of a subunit vaccine against JEV.

• Journal of Crop Science and Biotechnology
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• v.10 no.3
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• pp.159-162
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• 2007

Soybean Kunitz trypsin inhibitor(SKTI) protein is a small, monomeric and non-glycosylated protein containing 181 amino acid residues and is responsible for the inferior nutritional quality of unheated or incompletely heated soybean meal. The objective of this research is to confirm SSR marker(Satt228) tightly linked to the Ti locus using several germplasm accessions with TiTi or titi genotypes for MAS in soybean breeding programs. TiTi genotypes('Jinpumkong2', 'Clark', and 'William') had allele1 and titi genotypes(PI196168, C242, W60, and PI157440) had allele2 in Satt228 marker analysis. 'Jinpumkong2', 'Clark', and 'William'(TiTi genotype) had a Kunitz trypsin inhibitor protein of 21.5 kDa size, and PI196168, C242, W60, and PI157440(titi genotype) did not have the band in protein gel electrophoresis from the mature seed. Cosegregation between the SKTI protein(21.5 kDa size) and allele of Satt228 marker was observed in seven germplasm accessions with different genetic backgrounds. Any recombination between the SKTI protein and allele of the Satt228 marker was not observed. This result indicates that Satt228 marker may effectively utilized to select the plants with the titi genotype.