• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.2
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• pp.305-312
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• 2011

Bacillus anthracis(Ba) is a Gram-positive spore-forming bacterium that causes the disease anthrax. The feature of Ba is the presence of two large virulence plasmids, pXO1 and pXO2. Molecular genotyping of Ba has been difficult to the lack of polymorphic DNA marker. Ba isolated from Korea has been genotyped using various nucleotide analysis methods, such as 16s rDNA sequencing and multiple-locus variable-number tandem repeat (MLVA) analysis. We identified genotypes that represent a genetic lineage in the B1 cluster. This study emphasized the need to perform molecular genotyping when attempting to verify a strain-specific Ba.

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.255-261
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• 1987

Five independent Actinomycetes harboring plasmids were isolated from soil. Molecular weight of these plasmids was 55kb, 6.2kb, 4.4kb, 55kb and 7.0kb, respectively. Among them small and apprent high copy number plasmids, pJY501 of 4.4kb and pHY711 of 7.0kb, were selected. The plasmids purified by CsCl-EtBr density gradient centrifugation preserved the conformation of supercoiled covalently closed circular molecule, and an apparent copy number was estivated about 150 and about 35 per chromosome. The isolates carrying plasmids were assigned to the genus Streptomyces. For the purpose of introducing selection markers into the isolated plasmids, the tsr fragmemt of pIJ702 was inserted into the BclI site of pJY 501 and pJY711. And the recombinant plasmids constructed designated as pJY502 and pJY712 respectively.

• Journal of Environmental Health Sciences
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• v.50 no.1
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• pp.66-72
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• 2024

Background: Vibrio vulnificus is a serious opportunistic human pathogen that has a worldwide distribution in a variety of marine and estuarine environments. Objectives: For this reason, we investigated the distribution of Vibrio vulnificus in coastal areas of Gyeonggido Province from 2018 to 2022. Also, we analyzed the correlation between V. vulnificus leading to infection and two marine environmental factors (water temperature and salinity). Methods: We collected a total of 266 samples from six coastal area points (i.e., seawater, mudflats). Specimens were isolated using selective plating media and isolated strains were identified by a VITEK 2 system. To find the relevance of the isolation rates of V. vulnificus and number of cases of V. vulnificus infection, we summarized the data on 48 cases of V. vulnificus infection from the open data of the Korea Disease Control and Prevention Agency. Results: Among the 266 samples taken during the investigation period, 47 strains were isolated, and the separation rates of V. vulnificus were 17.7%. The monthly isolation rates of V. vulnificus were ranked in the order of August (53.8%), September (33.3%), June (28.6%), and July (21.1%). There was a positive correlation with the temperature of seawater, but salinity was not significant. The number of cases of V. vulnificus infection reported in Gyeonggi-do Province were 18 (37.5%) in September, 14 (29.2%) in August, and eight (16.7%) in October. The proportion was 83.3%. It was relevant to the isolation rates of V. vulnificus in the marine environmental sources. Conclusions: Our data showed that the number of V. vulnificus infection cases could be affected by changes in the distribution of V. vulnificus due to rise the temperature of seawater in the marine environment.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.116.5-116
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• 2001

When inertial navigation system(INS) employ more sensors that mutually orthogonal sets to three, the redundant sensor system can have improved reliability and accuracy. For the redundant system the placement of redundant sensors is related to the system performance and also the number and proper orientation of sensors are important. We consider INS sensor configurations using two IMUs comprised mutually orthogonal sets of three. We suggest several configurations using two IMUs and analyze the system performance and the FDI(fault detection and isolation) properties from suggested configurations.

• Structural Engineering and Mechanics
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• v.34 no.5
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• pp.663-666
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• 2010

The spectral content of ground displacement of the 10 largest last California earthquakes is studied. Specifically, the power spectral density function of the critical horizontal-component record of the closest-to-epicenter station is analyzed in each case. The results permit to state that horizontal ground displacement is a narrow-band process. This fact was previously noticed while trying to solve the large-base-displacement problem in isolated structures and it was fundamental in the solution of this issue; however, these preliminary results were limited in number to enable a statement like the foregoing one. Thus, the broader results presented herein were necessary.

• Journal of KSNVE
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• v.4 no.4
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• pp.487-496
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• 1994

Recently, the application of viscoelastic material in the field of vibration isolation has gradually increased due to its achievement in structural damping capacity, and many of the theoretical and experimental study has been carried out. In this study, the dynamic characteristics of the visoelastically supported cantilever beam, of which govering equation is based on the Bernoulli- Euler equation, is analyzed theoretically and experimentally. Expression for stiffness of multi-layered viscoelastic materal has been developed using variables such as frequency and number of layers, and further, based on this expression, damping characteristic of the beam is investigated with experimental verification.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.322-328
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• 2003

The Transformation-Associated Recombination (TAR) cloning technique allows selective isolation of chromosomal regions and genes from complex genomes. The procedure requires knowledge of relatively small genomic sequences that reside adjacent to the chromosomal region of interest. This technique involves homologous recombination during yeast spheroplast transformation between genomic DNA and a TAR vector that has 5'and 3' gene targeting sequences. In this study, we examined the minimum size of specific hooks required for a single-copy gene isolation and compared the utility of different TAR vectors, radial and unique vectors, by cloning the same single-copy gene. The efficiency of TAR cloning of the hHPRT gene was same using hooks varying from 750 to 63 bp. The number of transformants decreased approximately 20-fold when the TAR vector contained two unique hooks versus using a radial vector, but the percentage of positive recombinants increased over 2-fold when a unique TAR vector was used. Therefore, we suggest that the two-unique TAR vector is suitable for general TAR cloning given its high selectivity, and the radial TAR vector is more suitable when genomic DNA is in limited quantity, for example, DNA isolated from pathological specimens. Moreover, we confirm the minimal length of a unique sequence in a TAR vector is approximately 60 bp for a single-copy gene isolation.

• Land and Housing Review
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• v.2 no.3
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• pp.287-297
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• 2011

This paper presents the results of performance verification tests of the isolated flat plate apartment building with the laminated rubber bearings. The shaking table test is carried out in CABR(China Academy of Building Research) with two 1/10 scale isolation and non-isolation models under 4 excitation waves. The shaking table test is proceeding from x axis, y axis and x+y axis with different amplitude of acceleration values. The results show that, to non-isolated model, the natural vibration period is remarkably decreased and entered non-linear condition after moderate earthquake. Its accelerations become lager with increasing storey number and completely collapsed under large earthquake. The inter-storey shifts largely exceed the limit values of regulated displacement angles. But to isolated model, the natural vibration period of isolated modal is almost the same in all conditions and still in its elastic condition. The earthquake loading is greatly reduced and the accelerations of superstructure are greatly reduced. The inter-storey drifts are very small and can be neglected. The isolated model is in translational state and can be seen as a rigid whole. The displacements of isolation layer are in the allowable range. This experiment demonstrates that the seismic isolation is very effective to mitigate the influence of earthquake on structures and it is possible to increase the serviceability due to decrease the floor acceleration. facilities from their good states that is superior to non-isolated structure.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.11B no.3
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• pp.112-118
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• 2001

In the near future, the voltage of power system for passenger vehicle will be changed to 42V from existing 14V./ Because of increasing power and voltage ratings used in the vehicle the motor drive system has high switching dv/dt and it generates electromagnetic interference (EMI) To solve these problems multi-level inverter system may be used The feature of multi-level inverter is the output voltage to be synthesized from several levels of voltage Because of this feature high switching dv/dt and EMI can be reduced in the multi-level inverter system But as the number of level is increased manufacturing cost is getting expensive and system size is getting large. Because of these disadvantages the application of multi-level inverter has been restricted only to high power drives. The method to reduce manufacturing cost and system size is to integrate circuit of multi-level inverter into a few chips But isolated power supply and signal isolation circuit using transformer or opto-coupler for drive circuit are obstacles to implement the integrated circuit (IC) In this paper a drive circuit of 4-level inverter suitable for integration to hybrid or one chip is proposed In the proposed drive circuit DC link voltage is used directly as the power source of each gate drive circuit NPN transistors and PNP transistors are used to isolate to transfer the control signals. So the proposed drive circuit needs no transformers and opto-couplers for electrical isolation of drive circuit and is constructed only using components to be implemented on a silicon wafer With th e proposed drive circuit 4- level inverter system will be possible to be implemented through integrated circuit technology Using the proposed drive circuit 4- level inverter system is constructed and the validity and characteristics of the proposed drive circuit are proved through the experiments.

• Mycobiology
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• v.40 no.2
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• pp.100-106
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• 2012

Interest in commercial cultivation and product development of Cordyceps species has shown a recent increase. Due to its biochemical and pharmacological effects, Cordyceps militaris, commonly known as orange caterpillar fungus, is being investigated with great interest. Cultivation of C. militaris has been practiced on a large scale in order to fulfill a demand for scientific investigation and product development. Isolates of C. militaris can be easily established from both spores and tissue. For isolation of spores, ascospores released from mature stromata are trapped in sterile medium. Multi-ascospore isolates, as well as combinations of single ascospore strains, are used for production of fruiting bodies. Progeny ascospore strains can be isolated from artificial fruiting bodies, thus, the cycle of fruiting body production can be continued for a long period of time. In this study, we examined fruiting body production from multi-ascospore isolates and their progeny strains for three generations. $F_1$ progeny strains generally produced a larger number of fruiting bodies, compared with their mother multi-ascospore isolates; however, $F_2$ and $F_3$ progeny strains produced fewer fruiting bodies. Optimum preservation conditions could help to increase the vitality of the progeny strains. In order to retain the fruiting ability of the strains, further testing of various methods of preservation and different methods for isolation should be performed.