• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.1
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• pp.78-84
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• 2012

In this paper, we introduced the design technique about a Ka band receive module for millimeter wave seekers. The receiver module consists of a waveguide, circulator and transition for antenna connection, and a limiter and gain control amplifier for receiver protection. This module is comprised of a sum, azimuth and elevation channel for receiving monopules signal, and a SLB channel for the acquisition of jamming signal. In this paper, receiver gain and range of gain control dependent on ADC nonlinear characteristic was analyzed and designed for wide dynamic range receive. In the test result of the fabricated Ka-band receive, the frequency band is 1 GHz, the noise figure is as low as 8.2 dB, the gain is $56{\pm}2dB$, the dynamic range is 135 dB, the gain congtrol is more than 86 dB, the channel isolation is more than 35 dB.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.5
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• pp.36-41
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• 2007

We report the 94 GHz CPW branch-line bandpass filter for planar integrated millimeter-wave circuits. The branch-line coupler operates as a transversal filtering section by connecting the coupling ports to the open load stubs and taking the isolation port as the output node. For design of the 94 GHz branch-line bandpass filter, we built the CPW library and optimized the characteristic impedances and the lengths of the branch-line coupler and the open load stubs. The fabricated 94 GHz bandpass filter exhibits an insertion loss of 2.5 dB with an 11.7 % 3 dB relative bandwidth and the return loss is -18.5 dB at a center frequency of 94 GHz.

• Journal of the Korea Organic Resources Recycling Association
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• v.3 no.1
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• pp.21-34
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• 1995

For development of microbial additives applicable to in-vessel composting system of food waste, thermophilic bacteria which showed amylase, protease, lipase and cellulase activity were isolated from soil, compost and food waste. Among 81 isolates, the growth characteristic of 20 strains with high enzyme activity were examined. All strains are Gram positive rod with catalase activity and 17 strains are spore formers. At $50^{\circ}C$, most of the strains were able to grow from pH 5 to pH 10 and in presence of 8% of NaCl. In trypticase soy broth, the growth of these strains was greatly increased by aeration, but decreased at elevated temperature above $50^{\circ}C$.

• Journal of Life Science
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• v.14 no.1
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• pp.174-179
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• 2004

To develop high effiency biofertilizer, a bacterium having ability to solubilize inorganic phosphate was isolated from cultivated soils, using a sucrose minimal agar-hydroxyapatite medium. The strain was identified as Klebsiella sp. DA7l-1, based on the physiological and biochemical properties. The activity of solubilizing inorganic phosphate of Klebsiella sp. DA7l-1 against three types of insoluble phosphate such as tri-calcium phosphate, aluminium phosphate, hydroxyapatite were quantitatively determined. The results indicated that the strain solubilized hydroxyapatite. The MPS (mineral phosphate solubilizing) conditions of Klebsiella sp. DA7l-1, were measured to determine the optimal conditions. The optimal temperature and initial pH to solubilize insoluble phosphate in sucrose minimal medium were $30^{\circ}C$ and pH 6.0, respectively.

• The Journal of the Korean Society for Microbiology
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• v.13 no.1
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• pp.25-30
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• 1978

Among clincal isolates, most strains of Serratia marcescens were belonged to nonpigmented form, and several attempts were undertaken for the rapid and simple identification of these strains. Prodigiosin production of non-pigmented strains was uniformly negative in many kinds of solid media as well as in nutrient agar added with various amino acids and thiamine. On blood agar, colonies of S. marcescens turned gradually to grey or dark color by the lapse of incubation period and this characteristic seems to be able to utilize as an indicator for a primary isolation, and also generally paralleled with the results of dehydration of Tween 80 and lipase activity in soy bean oil medium although these reactions were by no means specific to S. marcescens. In order to rule out these non-specific reactions, other tests such as oxidase and sucrose fermentation are required for the final confirmation of this species.

• Korean Journal of Veterinary Research
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• v.36 no.1
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• pp.181-186
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• 1996

The present study was conducted to investigate the biochemical and serologic characteristic of Actinobacillus pleuropneumoniae isolated from pneumonic lungs of pigs during the period from January 1992 to April 1993. A pleuropneumoniae was isolated from 17(27.0%) of 63 growing pigs with respiratory signs and 21(6.4%) of 330 pneumonic lungs of slaughtered pigs. The seasonal isolation frequency of A pleuropneumoniae was higher in winter and spring than that in summer or fall. The biochemical and cultural properties of A pleluropneumoniae isolated from the pneumonic lungs of pigs were identical to those of the reference strains used. The isolates were highly susceptible to ampicillin, cephalothin, ceftiofur, ciprofloxacin(MIC : ${\leq}0.39{\mu}g/ml$) and moderately susceptible to amikacin, chloramphenicol, erythromycin, kanamycin, methicillin, penicillin-G, streptomycin(MIC : 0.78~25IU or ${\mu}g/ml$), respectively. Sulfadimethoxine, sulfamerazine, tylosine showed no response to the isolates(MIC : ${\geq}100{\mu}g/ml$). Among the 38 isolates, 21(55.3%) and 13(34.2%) were resistant to oxytetracycline aid lincomydn, respectively(MIC : ${\geq}50IU$ or ${\mu}g/ml$). The majority of 38 A pleuropneumoniae isolates were turned out as serotype 2(47.4%) or serotype 5(54.7%) and the remaining 3 isolates were evenly classified to serotype 7, 10 or 12. It was noted A pleuropneumonine serotype 5 isolates were more resistant to oxytetracycline than serotype 2 isolates.

• Journal of Life Science
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• v.14 no.2
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• pp.320-324
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• 2004

The objective of this study was investigate the characteristic of biosurfactant produced from the isolated strain. The strain was isolated from soil samples and identified as Bacillus sp. TBM 911-5 by physiological characteristics and the partial nucleotide sequence analysis of 16S rDNA. We measured the surface tension every 6 hours for 80 hours. The surface tension of the culture filtrate of Bacillus sp. TBM 911-5 was decreased to 29 mN/m. Biosurfactant concentration was determined by diluting the culture filtrate until the critical micelle concentration (CMC). The biosurfactant emulsified hydrocarbons, vegetable oil and crude oil. Using soybean oil as substrate, the maximum emulsification activity and stability was obtained from the biosurfactant. The biosurfactant produced from Bacillus sp. TBM 911-5 had strong properties as an emulsifying agent and an emulsion-stabilizing agent.

• Journal of Gifted/Talented Education
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• v.22 no.3
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• pp.729-755
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• 2012

As an effort to understand alienated gifted students, we investigated learning characteristics and learning tactics of a scientifically gifted student with economic difficulty and physical disadvantage. The student we studied is attending the Saturday Physics Class which is an after school science activity offered by our university. We adopted techniques of qualitative case study. Participant observation was carried out at the field and the interview was done with the participant, his mother, and his teacher of 5th grade. Field documents and self-reports were used to understand the student synthetically. As a result, learning characteristics of the participant could be summarized as a spontaneous learning which originated from the internal motivation and struggle for learning to overcome the sense of inferiority and isolation from the peers. The participant adopted a strategic method for learning to satisfy his learning desire given the circumstance of socioeconomic and physical disadvantage: the three tactics we found were various learning routes, meta-cognitive ability and fervent response.

• Fisheries and Aquatic Sciences
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• v.11 no.2
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• pp.88-97
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• 2008

Lipoproteins are complexes of lipids and specific apolipoproteins that are involved in lipid transport and redistribution among various tissues. In this study, we isolated full-length apolipoprotein cDNA sequences encoding apolipoprotein A-I (apoA-I), apoE, apoC-II, and apo-14 kDa in barred knifejaw, Oplegnathus fasciatus. In addition, we reconstructed phylogenetic trees and investigated mRNA tissue distributions. Alignment analyses of amino acid sequences revealed that secondary structures of the polypeptides apoA-I, apoE, and apoC-II in barred knifejaw are well conserved with their teleostean and mammalian counterparts in terms of characteristic tandem repetitive units forming amphipathic ${\alpha}$-helices. Both the sequence alignment data and cleavage sites of apo-14 kDa indicated a clear differentiation between Percomorpha and Cypriniformes. Meanwhile, the phylogenetic trees of apolipoprotein sub-families suggested that the common ancestor prior to the split of the Actinopterygii (ray-finned fishes) and Sarcopterygii (tetrapods) would have possessed the primordial protein-encoding genes. Tissue distribution of each apolipoprotein transcript determined by semi-quantitative RTPCR showed that barred knifejaw apoA-I transcripts were more or less ubiquitously expressed in the liver, intestines, brain, muscle, spleen, and kidney. The most striking difference from previous observations on barred knifejaw was the ubiquitous expression of apoE across all somatic tissues. Barred knifejaw apoC-II showed tissue-specific expression in the liver and intestines, while the liver and brain were the major sites of apo-14kDa mRNA synthesis.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.2
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• pp.191-200
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• 2009

Dental Pulp Stem Cells are superior to other types of adult stem cell. Because of teeth are easy to access and are extracted throughout life. A supernumerary tooth is an important clinical problem found in various populations of the world. The incidence of supernumerary teeth varies depending on the literature source. Pediatric dentists are routinely extracted them. However, no studies have been reported regarding Dental Pulp stem cells in a supernumerary tooth, and we failed to note that a valuable source of human stem cell. Herein, we tried to show that a supernumerary tooth contains cells that display the characteristic features of stem cells.