• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.415-415
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• 2012

ZnO nanostructures were synthesized by a vapor phase transport process in a single-zone furnace within a horizontal quartz tube with an inner diameter of 38 mm and a length of 485 mm. The ZnO nanostructures were grown on Au-catalyzed Si(100) substrates by using a mixture of zinc oxide and graphite powders. The growth of ZnO nanostructures was conducted at $800^{\circ}C$ for 30 min. High-purity Ar and $O_2$ gases were pushed through the quartz tube during the process at a flow rate of 100 and 10 sccm, respectively. The sequence of ON/OFF cycles of the Ar gas flow was repeated, while the $O_2$ flow is kept constant during the growth time. The Ar gas flow was ON for 1 min/cycle and that was OFF for 2 min/cycle. The structure and optical properties of the ZnO nanostructures were investigated by field-emission scanning electron microscope, X-ray diffraction, temperature-dependent photoluminescence. The preferred orientation of the ZnO nanostructures was along c-axis with hexagonal wurtzite structure.

• Journal of Life Science
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• v.11 no.5
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• pp.400-404
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• 2001

A new human endogenous retroviral family (HERV-S) has recently been identified from human X chromosome. It is 6.7 kb in length and has a typical retroviral structure with LTR-gag-pol-env-LTR. Using the PCR and sequencing approach, we investigated LTR elements of the HERV-S family from a human genomic DNA. Four LTR elements (HSL-1, HSL-5, HSL-10, HSL-11) were identified and have a high degree of sequence similarity(96-99%) with that of the HERV-S. Phylogenetic analysis from the HERV-S family indicated that the LTR elements were mainly divided into 2- groups through evolutionary divergence in the primate evolution. Further investigation of the HERV-S LTR elements in primates may cast light on the integration timing into the primate genome and understanding of human evolution.

• Korean Journal of Microbiology
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• v.36 no.4
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• pp.249-253
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• 2000

The genetic diversity among Korean cyanobacteria was assessed by restriction fragment length polymorphism(RFLP) analysis of PCR products from the phycocyanin locus. Strains of all the genera tested were successfully amplified, and the size of amplified fragments was approximately 700bp. The restriction patterns generated by AluI, MspI, and HaeIII were conserved for strains within each of genera studied and were specific to the genus level. Intrageneric delineation of strains was revealed by the enzyme, CfoI for members of genera Anabeana and Synechocystis. Phenogram derived from the different RFLP patterns revealed a coherent cluster among Anabeana, Chlorogloea, and Synechocystis strains. PC-RFLP methods provided useful tools for classification of cyanobacteria.

• Journal of Microbiology and Biotechnology
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• v.9 no.4
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• pp.393-397
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• 1999

The gene (galE) encoding UDP-galactose-4-epimerase, operative in the galactose metabolic pathway, was cloned together with the $\beta$-galactosidase gene (lacZ) from Lactococcus lactis ssp. lactis ATCC7962 (L. lactis 7962). galE was found to have a length of 981 bps and encoded a protein with a molecular mass of 36,209 Da. The deduced amino acid sequence showed a homology with GalE proteins from several other microorganisms. A Northern analysis demonstrated that galE was constitutively expressed by its own promoter. When galactose or lactose was added into medium, the galE transcription was induced by several upstream promoters. The structure of the gal/lac operon of L. lactis 7962 was partially characterized and the gene order around galE was galT-lacA-lacZ-galE-orfX.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.793-799
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• 2012

A gene related to high pristinamycin yield in Streptomyces pristinaespiralis was selected by amplified fragment length polymorphism (AFLP) and its functions were investigated by gene disruption. First, a 561 bp polymorphic sequence was acquired by AFLP from high-yield recombinants compared with the S. pristinaespiralis ancestor ATCC25486, indicating that this approach is an effective means of screening for valuable genes responsible for antibiotic yield. Then, a 2,127 bp open reading frame of a gene designated spy1 that overlaps with the above fragment was identified and its structure and biological functions were investigated. In silico analysis of spy1 encoding a deduced 708-amino-acid-long serine/threonine protein kinase showed that it only contains a catalytic domain in the N-terminal region, which is different from some known homologs. Gene inactivation of chromosomal spy1 indicated that it plays a pleiotropic regulatory function in pristinamycin production, with a positive correlation to pristinamycin I biosynthesis and a negative correlation to pristinamycin II biosynthesis.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.37-37
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• 2018

The genus Crepidiastrum (Asteraceae), containing ca. 20 species, is mainly distributed in Asia. Crepidiastrum denticulatum, an edible plant that commonly call "e-go-deulppae-gi" in Korean, distributes in Korea, Japan, and China. The complete chloroplast (cp) genome sequences of C. denticulatum was characterized from MiSeq2000 (Illumina Co.) pair-end sequencing data. The cp genome of C. denticulatum has a total sequence length of 152,689 bp and show a typical quadripartite structure. It consists of the large single copy (LSC: 84,022 bp), small single copy (SSC: 18,519 bp), separated by a pair of inverted repeats (IRs: 25,074 bp) and contains 110 unique genes and 18 genes duplicated in the IR regions. Our comparative analysis identified three cpDNA regions (matK, rbcL, and psbA-trnH) from three Crepidiastrum species, which may be useful for molecular identification of each species, and providing a guideline for its clear confirming about dried medical herb.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.5-5
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• 2018

Ginseng (Panax ginseng C.A. Meyer), one of the most widely used medicinal plants in traditional oriental medicine, is used for the treatment of various diseases. It has been classified according to its cultivation environment, such as field cultivated ginseng (FCG) and mountain cultivated ginseng (MCG). However, little is known about differences in gene expression in ginseng roots between field cultivated and mountain cultivated ginseng. In order to investigate the whole transcriptome landscape of ginseng, we employed High-Throughput sequencing technologies using the Illumina HiSeqTM2500 system, and generated a large amount of sequenced transcriptome from ginseng roots. Approximately 77 million and 87 million high-quality reads were produced in the FCG and MCG roots transcriptome analyses, respectively, and we obtained 256,032 assembled unigenes with an average length of 1,171 bp by de novo assembly methods. Functional annotations of the unigenes were performed using sequence similarity comparisons against the following databases: the non-redundant nucleotide database, the InterPro domains database, the Gene Ontology Consortium database, and the Kyoto Encyclopedia of Genes and Genomes pathway database. A total of 4,207 unigenes were assigned to specific metabolic pathways, and all of the known enzymes involved in starch and sucrose metabolism pathways were also identified in the KEGG library. This study indicated that alpha-glucan phosphorylase 1, putative pectinesterase/pectinesterase inhibitor 17, beta-amylase, and alpha-glucan phosphorylase isozyme H might be important factors involved in starch and sucrose metabolism between FCG and MCG in different environments.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.8
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• pp.11-19
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• 1994

The matching probability P(ο/$\lambda$), of the signal sequence(ο) observed for a finite time interval with a HMM (Hidden Markov Model $\lambda$) indicates the probability that signal comes from the given model. By utilizing the fact that the probability represents matching score of the observed signal with the model we can recognize an unknown signal pattern by comparing the magnitudes of the matching probabilities with respect to the known models. Because the algorithm however uses floating point variables during the computing process hardware implementation of the algorithm requires floating point units. This paper proposes an integer algorithm which uses positive integer numbers rather than float point ones to compute the matching probability so that we can economically realize the algorithm into hardware. The algorithm makes the model parameters integer numbers by multiplying positive constants and prevents from divergence of data through the normalization of variables at each step. The final equation of matching probability is composed of constant terms and a variable term which contains logarithm operations. A scheme to make the log conversion table smaller is also presented. To analyze the qualitive characteristics of the proposed algorithm we attatch simulation result performed on two groups of 10 hypothetic models respectively and inspect the statistical properties with repect to the model order the magnitude of scaling constants and the effect of the observation length.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.4
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• pp.37-46
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• 1996

In this paper, we analyzed the performance improvement of the DS-CDMA/dPSK cellular mobile communication system with CCI canceller and RAKE receiver techniques in mobile radio channel which is characterized by AWGN, Multi-user interference (mUI) and frequency-selective rayleigh fading. System capacity i.e., number of user per cell has been derived and the evaluated results are shown in figuraes as a function of PN code sequence length, number of RAKE receiver tap, BER and E$_{b}$/N$_{o}$. The voice activity factor is assumed to be 3/8 the number of sectors in a cell 3 and MUI is modeled as gaussian process. From the results, the capacity of the DS-CDMA/DPSK cellular mobile communication system is improved by adopting CCI canceller. When we adopt the RAKE receiver to mitigate the multipath fading, the error performance is improved and the amount of improvement is proportional ot the number of taps L in the case that each tap contains a signal component and the better of improvement can be obtained, the smaller of the SNR difference in each tap. The system capacity is more increased when the CCI canceller and the RAKE receiver is used in cascade.

• Composites Research
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• v.33 no.3
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• pp.133-139
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• 2020

In this research, the vibration characteristics of composite quadcopter are analyzed, and avoidance design and analysis are performed to avoid resonance. The full platform of a commercial quadcopter with composite rotor arm is analyzed to see the vibration characteristics using FEM program. The manufactured stacking sequences of rotor arm is used for analysis, and the natural frequencies are compared with experimental results and simple analytic model results. It is also confirmed that the natural frequency of the particular mode is included within the operation range of the motor. The resonance avoidance design is carried out by selecting three variables from the existing model: stacking sequence, rotor-arm pipe length, and pipe thickness.