• 전기의세계
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• v.26 no.2
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• pp.84-88
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• 1977

In this paper we apply the maximum principle to design of time optimal nonlinear sampled-data control systems. We introduce the general design procedures and the mathematical formalas for time optimal processes and trajectories. Then we show the application of the technique to determine the optimal control signal, control sequence, switching time and sampling period to the given 4th order process.

• Journal of Microbiology and Biotechnology
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• v.30 no.1
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• pp.109-117
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• 2020

Cre recombinase is widely used to manipulate DNA sequences for both in vitro and in vivo research. Attachment of a trans-activator of transcription (TAT) sequence to Cre allows TAT-Cre to penetrate the cell membrane, and the addition of a nuclear localization signal (NLS) helps the enzyme to translocate into the nucleus. Since the yield of recombinant TAT-Cre is limited by formation of inclusion bodies, we hypothesized that the positively charged arginine-rich TAT sequence causes the inclusion body formation, whereas its neutralization by the addition of a negatively charged sequence improves solubility of the protein. To prove this, we neutralized the positively charged TAT sequence by proximally attaching a negatively charged poly-glutamate (E12) sequence. We found that the E12 tag improved the solubility and yield of E12-TAT-NLS-Cre (E12-TAT-Cre) compared with those of TAT-NLS-Cre (TAT-Cre) when expressed in E. coli. Furthermore, the growth of cells expressing E12-TAT-Cre was increased compared with that of the cells expressing TAT-Cre. Efficacy of the purified TAT-Cre was confirmed by a recombination test on a floxed plasmid in a cell-free system and 293 FT cells. Taken together, our results suggest that attachment of the E12 sequence to TAT-Cre improves its solubility during expression in E. coli (possibly by neutralizing the ionic-charge effects of the TAT sequence) and consequently increases the yield. This method can be applied to the production of transducible proteins for research and therapeutic purposes.

• The Journal of Korean Society of Virology
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• v.26 no.1
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• pp.131-137
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• 1996

The sequences of p10 gene its promoter of Hyphantria cunea NPV were determined. According to the sequence analysis, the putative p10 gene ORF has 285 bp. The 5'-non-coding leader sequence of the p10 gene promoter contained the TATA box and the putative transcription initiation site TAAG motif. Poly (A) tail signals, AATAAA sequence was at site 65 base upstream from the 3' terminus. The deduced amino acid sequence of p10 protein was 95 with a predicted molecular weight of 10.26 kDa. In the p10 protein sequence, a hydrophobic region was present at the N-terminus of the protein, whereas the C-terminus was highly hydrophilic. The p10 protein of H. cunea NPV did not contain cysteine, histidine, trytophan, tryptophane, tyrosine, glutamine and asparagine residues.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.1
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• pp.56-60
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• 2005

In the power-line communication(PLC) systems, the power line is a wired medium. However, the power line channel has the multi-path fading characteristics like the wireless channel in the wireless communication systems because it has the signal reflection and divergence by the impedance mismatching between many branch lines and loads. So the analysis of the multi-path characteristics is very important, and it has been doing by the several measurement methods for the impulse response between the transmitter and the receiver. PN sequence method has originally been used as a wideband impulse response measurement mettled for wireless channel, but it is recently being applied to not only the wireless channel but also the wired channel like the power line channel. This method is more useful and effective for the long distance communication channel like the medium voltage power distribution line with the multi-paths[1]. In this thesis, we have measured impulse response for the medium voltage power distribution line channel by the wideband measurement method using PN sequence, analytically studied the measured data and presented the results.

• Korean Journal Plant Pathology
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• v.11 no.3
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• pp.271-277
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• 1995

The RNA nucleotide sequences of the 3/-noncoding regions (3'-NCRs) of two Korean strains of turnip mosaic virus (TuMV), Ca and cqs, have been determined from their cDNA clones that encompassed the 3'-terminal regions of the viral genomic RNAs. The 3'-NCRs of both strains were 209 nucleotides long, terminated with GAC residues and poly (A) tails. The potential polyadenylational signal motif, UAUGU, was located 140 nucleotides upstream from the poly (A) tail in each of the virus. A highly conserved hexanucleotide sequence [A G U G A/U G/C], which was common in the 3'-NCRs of the potyvirus RNAs, was also found at the regions of 119 bases upstream from the 3'-end. Comparison of the 3'-NCRs of the two Korean isolates with those of four strains from Canada, China and Japan showed significantly identical genotypes (94.3∼99.5%). The secondary structure of three loops with long stems was found within the 3'-NCRs by sequence analysis. The substituted bases in the region among the six TuMV strains did not alter their secondary structures. Length of the 3'-NCRs of the know 11 potyviral RNAs and TuMV RNAs was different from one another and their nucleotide sequences showed 55.7% to 24.0% of homology. The 3'-NCR, therefore, is considered to be useful for phylogenetic studies in potyviruses.

• Journal of Power Electronics
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• v.18 no.4
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• pp.1245-1254
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• 2018

The stability of a grid-connected system (GCS) has become a critical issue with the increasing utilization of renewable energy sources. Under grid faults, however, a grid-connected inverter cannot work efficiently by using only the traditional droop control. In addition, the unbalance factor of voltage/current at the common coupling point (PCC) may increase significantly. To ensure the stable operation of a GCS under grid faults, the capability to compensate for grid imbalance should be integrated. To solve the aforementioned problem, an improved voltage-type grid-connected control strategy is proposed in this study. A negative sequence conductance compensation loop based on a positive sequence power droop control is added to maintain PCC voltage balance and reduce grid current imbalance, thereby meeting PCC power quality requirements. Moreover, a stable analysis is presented based on the small signal model. Simulation and experimental results verify the aforementioned expectations, and consequently, the effectiveness of the proposed control scheme.

• Journal of Microbiology and Biotechnology
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• v.3 no.3
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• pp.139-145
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• 1993

The nucleotide sequence of the xylanase gene (xynS) from alkali-tolerant Bacillus sp. YA.14 was determined and analyzed. A 639 base pairs open reading frame for xynS gene was observed and encoded for a protein of 213 amino acids with a molecular weight of 23, 339. S1 nuclease mapping showed that the transcription initiation site of the xynS gene did not exist in the cloned DNA. Ribosome binding site sequence with the free energy of -18.8 Kcal/mol was observed 8 base pairs upstream from the initiation codon, ATG. The proposed signal sequence consisted of 28 amino acids, of which 3 were basic amino acid residues and 21 were hydrophobic amino acid residues. When the amino acid sequences of xylanases were compared, Bacillus sp. YA-14 xylanase showed 48% homology with Bacillus sp. YC-335 xylanase and 96% homology with xylanases from B. subtilis and B. circulans.

• Journal of Microbiology and Biotechnology
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• v.12 no.5
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• pp.773-779
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• 2002

A gene (hap) encoding aminopeptidase from the chromosomal DNA of Bacillus licheniformis was cloned. The gene is 1,347 bp long and encodes a 449 amino acid preproprotein with a major mature region of 401 amino acids (calculated molecular mass 43,241 Da). N-Terminal sequence of the purified protein revealed a potential presence of N-terminal propeptide. The deduced primary amino acid sequence and the mass analysis of the purified protein suggested that a C-terminal peptide YSSVAQ was also cleaved off by a possible endogeneous protease. Tho amino acid sequence displayed 58% identity with that of the aminopeptidase from alkaliphilic Bacillus halodurans. This bacterial enzyme was overexpressed in recombinant Escherichia coli and Bacillus subtilis cells. Clones containing the intact hap gene, including its own promoter and signal sequence, gave rise to the synthesis of extracellular and thrmostable enzyme by B. subtilis transformants. The secreted protein exhibited the same biochemical properties and the similar apparent molecular mass as the B. lichenzyormis original enzyme.

• Journal of Microbiology and Biotechnology
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• v.3 no.4
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• pp.224-231
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• 1993

The nucleotide sequence of the xylanase gene (xynY) from alkalophilic Bacillus sp. YC-335 was determined and analyzed. An open reading frame of 1, 062 base pairs for xynY gene was observed and encoded for a protein of 354 amino acids with a molecular weight of 38, 915. S1 nuclease mapping showed that the transcription initiation sites of the xynY gene were different in Bacillus sp. YC-335 and Escherichia coli HB101 (pYS55). S1 mapping also showed that -10 region of the xynY gene recognized by RNA polymerases of E. coli and Bacillus sp. YC-335 were TACAGT and TATGAT , respectively. A ribosome binding site sequence with the free energy of -17.0 Kcal/mol was observed 9 base pairs upstream from the unusual initiation codon, TTG. The proposed signal sequence consisted of 27 amino acids, 2 of which were basic amino acid residues and 21 were hydrophobic amino acid residues. When the amino acid sequences of xylanases were compared, Bacillus sp. YC-335 xylanase showed more than 50% homology with xylanases from B. pumilus, B. subtilis, and B. circulans.

• Archives of Pharmacal Research
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• v.19 no.6
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• pp.497-501
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• 1996

A gene coding for triosephosphate isomerase (TPI) from a rat skeletal muscle cDNA library was cloned and its nucleotide sequence was determined. The 1, 348-bp cDNA clone contains 24 bp $5^I$ noncoding region, the entire 750 bp coding region corresponding to a protein of 249 amino acids, $547bp 3^I$ noncoding region and part of a poly(A) tail. It also contains a polyadenylation signal, AATAAA, starting from 17 bp upstream of the poly(A) tail. The calculated molecular weight of rat TPI is 27.8 kDa and the net charge is +4. The deduced amino acid sequence from rat TPI CDNA sequence has 93% and 94% homology with that of mouse and human clones, respectively. The amino acids at the residue of Asn12, Lys14, His96, Glu 166, His96, His101, Ala177, Tyr165, Glu13O, Tyr2O9, and Ser212 in catalytic site are completely identical, confirming that the functional residues in TPI proteins are highly conserved throughout evolution. The most profound characteristic of rat TPI enzyme, compared with other TPIs, is that there are five cysteine substitutions at the residue of 21, 27, 159, 195 and 204. A Glu123 instead of Gly was found in rabbit, rhesus, mouse and human sequences. Through the method of RT-PCR, the mRNA transcription level of TPI gene was found to be different among various tissues and was highest in muscle.