• Journal of Korean Association for Spatial Structures
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• v.10 no.3
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• pp.49-56
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• 2010

In this study, the control performance of a smart top-story isolation system for tall buildings subjected to wind excitation was investigated. To this end, a 77-story tall building structure was employed and wind loads obtained from wind tunnel test were used for numerical simulations. The top-story of an example structure is separated from the main structure by a smart base isolation system composed of friction pendulum systems (FPS) and MR dampers. The primary purpose of the smart top-story isolation system is to mitigate the dynamic responses of the main structure, but the excessive movement of the isolated top story may cause the unstableness of the building structure. Therefore, the skyhook control algorithm was used to effectively reduce both responses of the isolated top story and the main structure. The control performance of the proposed smart top-story isolation system was investigated in comparison with that of the passive top-story isolation system. It has been shown from numerical simulation results that the smart top-story isolation system can effectively reduce wind-induced responses of the example building structure compared to the passive top-story isolation system with reduction of the top-story movement.

• Korean Journal of Veterinary Research
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• v.39 no.6
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• pp.1151-1160
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• 1999

This study was conducted to detect the toxoplasma-specific DNA in peripheral blood collected from cats experimentally infected with Toxoplasma gondii (RH strain) and from domiciled cats by B1 gene-base polymerise chain reaction(PCR). The sensitivity of oligonucleotide primer, T-1 & T-2, designed from toxoplasma B1 gene amplification method was compared with parasite detection by mouse inoculation(MI). And also, latex agglutination test(LAT) and indirect fluorescent antibody test(IFAT) were conducted to detect the fluctuation of serum antibodies compared with the detection of toxoplasma by PCR and MI. Toxoplasma B1 gene PCR was shown consistently high sensitivity and the results obtained by PCR agreed completely with those from MI. All blood samples collected before infection with T gondii gave negative results by PCR and MI. Also, toxoplasma Bl gene PCR was not cross reaction with Neospora caninum DNA and normal cat leucocyte as controls. The toxoplasma-specific DNA was detected by PCR in blood of 5 cats experimentally infected with T gondii 6 days after infection and the detection of this specific-DNA was long lasted in blood for 64 days after infection. The detection of toxoplasma-specific DNA by PCR could be identified as few as 10 tachyzoites and the isolation of T gondii by MI could be isolated as few as 1 tachyzoite from tenfold serial dilution of T gondii with normal cat blood, respectively. In healthy domiciled cats, the toxoplasma-specific DNA and the parasite were detected and isolated in blood from 3 of 56(5.3%) cats by both PCR and MI, respectively. In the results of antibody test from the total 56 heads of healthy domiciled cats, the positive rates are 15(26.7%) by LAT and 19(33.9%) by IFAT. These results suggest that PCR detection of toxoplasma can be applied as a sensitive and specific diagnostic and research tool.

• Journal of Dairy Science and Biotechnology
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• v.23 no.1
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• pp.65-71
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• 2005

Powered infant formula and baby food contaminated with Enterobacter sakazakii were reported to cause infection among infants and to be associated with sporadic cases and outbreaks of sepsis, menigitis, cerebritis, and necrotizing enterocolitis. Salmonella contamination of infant formula has also been responsible for multiple outbreaks. Other species of Enterobacteriaceae in powdered infant formula may be causative agents, about which there has been no report. Other pathogenic bacteria have been isolated from powdered infant formula but they were not associated with outbreaks among infant. While Enterobacter sakazakii caused disease in all age groups, premature infants under 28 days old and with birth weight are most sensitive to its infection. Even if low contamination level of the bacteria in powdered infant formula and baby food may not cause infection, the possibility to multiplicate during preparation and storage of reconstituted formula may increase. The etiological factors and pathogenecity of S. sakazakii have not been elucidated. There were wide variability in phenotype and genotype between its strains. S. sakazakii has been isolated from factory facility and surroundings more frequently than Salmonella and thus factory environment should be the source for post-processing contamination of the formula with S. sakazakii. Considering current technology to manufacture power infant formula and baby food it is impossible to sterilize powdered formula but the frequency of outbreak hazard by S. sakazakii can be reduced by pasteurizing the formula base before drying and shortening storage time of the reconstituted formula.

• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.7_spc
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• pp.435-441
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• 2016

The Korean peninsula has known as a minor-to-moderate seismic region. However, some recent studies had shown that the maximum possible earthquake magnitude in the region is approximately 6.3-6.5. Therefore, a seismic vulnerability assessment of the existing infrastructures considering ground motions in Korea is necessary. In this study, we developed seismic fragility curves for a continuous steel box girder bridge and two typical transmission towers, in which a set of seven artificial and natural ground motions recorded in South Korea is used. A finite element simulation framework, OpenSees, is utilized to perform nonlinear time history analyses of the bridge and a commercial software, SAP2000, is used to perform time history analyses of the transmission towers. The fragility curves based on Korean ground motions were then compared with the fragility curves generated using worldwide ground motions to evaluate the effect of the two ground motion groups on the seismic fragility curves of the structures. The results show that both non-isolated and base-isolated bridges are less vulnerable to the Korean ground motions than to worldwide earthquakes. Similarly to the bridge case, the transmission towers are safer during Korean motions than that under worldwide earthquakes in terms of fragility functions.

• Journal of Korean Association for Spatial Structures
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• v.8 no.5
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• pp.75-82
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• 2008

In this study, the possibility of vibration control of high-rise building structures by applying top-story isolation has been investigated. To this end, El Centro NS (1940) earthquake load is applied to 20- and 50-story building structures for numerical analysis. Artificial wind loads are used to evaluate the serviceability of example structures against wind vibration. As the number of isolated stories of example buildings is changed, structural responses has been evaluated to investigate optimal isolated building mass. And the natural period of isolation systems for top-story isolation is varied to investigate the improvement of control performance compared with the fixed base structure. Based on the analytical results, the top-story isolation system can be used as a hued mass damper and effectively reduce the structural responses of high-rise buildings against wind and seismic loads.

• Korean Journal of Veterinary Service
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• v.28 no.4
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• pp.375-385
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• 2005

The present study was conducted to investigate the genetic profile of two prevalent avian pathogens in Korea namely, Newcastle disease virus (NDV) and infectious bursal disease virus (IBDV). Two farms located in Yeongi-gun, Chungnam were selected for this study. The two viruses were isolated from various organs (spleen, trachea, bursa of Fabricius) of deceased chickens that showed clinical symptoms of Newcastle Disease or Infectious bursal disease like swelling and congestion of the F bursa, facial edema, lacrimation, greenish yellow diarrhea as well as pathological signs like airsacculitis, haemorrhages in the intestines and so on. For analysis of NDV and IBDV, a 466 and 435 base pair fragments corresponding to the HN and VP2 regions which are highly conserved among related strains of NDV and IBDV, respectively, were amplified by RT-PCR and analyzed by sequencing. Comparison of the VP2 region showed a $99.3\%$ homology between the Korean IBDV isolate and the BJ836-attenuated vaccine strain. In contrast, the HN region of the Korean NDV isolate only has an 83 to $84\%$ homology with the vaccine strains LaSota, B1 and VGGA. Our findings reveal that the prevalent NDV strain in Korea is genetically different from the vaccine strains and may explain the recent outbreaks of Newcastle disease in the region.

• Korean Journal of Microbiology
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• v.53 no.2
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• pp.137-140
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• 2017

Caballeronia sordidicola strain PAMC 26510 was isolated from Psoroma sp., a lichen material, collected from Barton Peninsula of King George Island in Antarctica. The draft genome sequence of PAMC 26510 consisted of 224 contigs and they was 7,872,143 base pairs with 59.7% G+C content. The genome included 7,580 protein coding sequences and 6 ribosomal RNA genes and 46 tRNA genes. The strain PAMC 26510 is also a metabolic generalist as we have observed in previous genomic studies in the arctic strain of Caballeronia sordidicola. The draft genomic sequences of PAMC 26510 had six CRISPR arrays on six contigs, and there were two clusters of CRISPR-associated genes that were linked with respective CRISPR arrays.

• Korean Journal of Microbiology
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• v.53 no.2
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• pp.141-143
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• 2017

Caballeronia sordidicola strain PAMC 26577 was isolated from Cladonia sp., a lichen collected from Svalbard Archipelago in the Arctic Ocean. Draft genomic sequences of PAMC 26577 were determined using Illumina and 182 contigs were submitted to GenBank and N50 value was 159,226. The genome of PAMC 26577 was comprised of 8,334,211 base pairs and %G+C content was 59.4. The genome included 8 ribosomal RNA genes and 51 tRNA genes as non-coding sequences. Protein-coding genes were 8,065 in number and they included central metabolism genes as well as butanol/butyrate biosynthesis, polyhydroxybutyrate metabolism, serine cycle methylotrophy genes, and glycogen metabolism. Membrane transporters were more than two-hundreds in number, but sugar phosphotransferase system and TRAP transporters were lacking. PAMC 26577 lacked CRISPR-associated sequences and proteins. No transposable elements were observed and there were only limited number of phage remnant regions with 11 phage-related genes.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.342-343
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• 2017

Bacillus velezensis T20E-257 was isolated from the root tissue of a tomato plant and exhibited plant growth-promoting activity. Here we present the complete genome of strain T20E-257. The genome contains 3,900,066 base pairs with a G + C content of 46.7% in 2 contigs. The genome includes 3,708 coding sequences, 27 rRNAs, and 86 tRNAs. We found gene clusters encoding secondary metabolites with an antimicrobial activity and genes related to the production of indole-3-acetic acid and 2,3-butanediol, which play a role in plant growth and health.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.351-353
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• 2017

Chryseobacterium sp. strain T16E-39, isolated from roots of a tomato plant, promotes plant growth and suppresses phytophthora blight and bacterial wilt diseases. The complete genome of strain T16E-39 consists of a circular chromosome with 4,872,888 base pairs with a G + C content of 35.22%. The genome includes 4,289 coding sequences, 15 rRNAs, and 71 tRNAs. We detected genes involved in phosphate solubilization, phytohormone regulation, antioxidant activity, chitin degradation, and the type IX secretion system (T9SS) that may be related to growth promotion and disease suppression in plants.