• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.526-533
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• 1999

Two species of antimicrobial agent producing bacteria and one sensitive strain were isolated from soil. Those were identified as B. subtilis, B. licheniformis, and Curtobacterium sp. by morphological, biochemical, physiological and chemotaxonomic characteristics. These were designated as B. subtilis cx1, B. licheniformis cy2 and Curtobacterium sp. cf3, respectively. Antimicrobial agent produced by B. subtilis cx1 showed high antibacterial activity against gram positive bacteria including of B. subtilis, Curtobacterium sp., L. mesenteroids, Staphy. aureus, S. faecalis and even gram negative bacteria, P. aeruginosa. Antimicrobial agent from B. licheniformis cy2 showed slightly lower antimi crobial activity than that from B. subtilis cx1. These two strains showed maximum production of antimicrobial agents at 30oC for 9~21hr cultivation. Curtobacterium sp. cf3 showed more sensitive activity than a sensitive strain of B. subtilis ATCC 6633 which was same genus or species with the B. subtilis cx1 and B. subtilis cy2, when the antimicrobial agent producing strains, B. subtilis cx1 and B. subtilis cy2, were directly applied onto these sensitive lawns.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.8
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• pp.1416-1421
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• 2008

A 10 dB branch line hybrid coupler included with defected ground structure (DGS) is proposed. In this contribution, a contact between the grounded metal housing and DGS is avoided, which has been a serious problem in applying DGS to high frequency circuits. An isolation between the metal housing and the DGS pattern is provided by inserting additional substrate between DGS and the metal package. Therefore, it is possible to design branch line hybrid couplers having highly asymmetric power dividing ratio using these DGS structure, which is demonstrated in this paper. The designed and fabricated branch line hybrid coupler using DGS is well packaged in a metal housing without touching the ground metal directly. The measurement is performed under realistic practical operating situations because it is packaged in a metal housing. The measured performances of the fabricated 10dB coupler shows a 1:9 asymmetric power dividing ratio at output ports, as predicted. In addition, the measured performances in terms of matching, isolation, and phase difference are in excellent agreement with the simulated characteristics.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.4
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• pp.807-811
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• 2001

In this paper we proposed a dual-frequency circular sector microstrip antenna with orthogonal polarized modes and high isolation between the two feeding ports. And then we designed a transceiver operating at 5.6 GHz for transmitting and at 5.5 GHz for receiving. The good isolation provided by the proposed antenna is used as the basis for the transmit-receive filtering of transceiver. The operating frequencies and polarization characteristics of the proposed antenna is calculated by using a cavity model. The 5-parameters and radiation patterns of the antenna are measured. A power amplifier and a low noise amplifier are designed and integrated with antenna to make a transceiver, which has about 13dB transmitting gain and about 8㏈ receiving gain.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.1
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• pp.17-24
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• 2002

In this paper, we propose a new watermarking method using isolation of invalid blocks for image authentication. We embed messages into the high frequency band in the DCT domain because of its imperceptibility and fragility. And we were able to inspect the identity of valid blocks between error corrected original images and watermarked images through experiments. As a result, we found that the watermarked image is enough to extract binary messages. Therefore, the extra information such as the original image or watermark was not necessary in our extracting process. Experiment results show that the proposed method can be used successfully for image authentication.

• Journal of KIISE:Databases
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• v.32 no.1
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• pp.86-99
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• 2005

In this paper, we suggest a system which automatically verifies and tunes transaction processing database applications based on program analysis technology. This system automatically verifies two kinds of transaction processing errors. The first case is the un-closed transaction. In this case, data is not updated as expected or performance of overall system can decrease seriously by locking some database tables until the process terminates. The second case is the miss-use of transaction isolation(inking) level. This causes runtime exception or abnormal termination of the program depending on runtime environment. This system automatically tunes two kinds of inefficient definition of transaction processing which decrease the performance of overall system. The first case happens when opened transaction is closed too late. And the second case happens when transaction isolation level is set too high.

• Nuclear Engineering and Technology
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• v.42 no.1
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• pp.9-16
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• 2010

Experimental examinations for evaluating fracutres were conducted by using transparent replicas of a single fracture in order to obtain the fracture data to contribute to the methodlogy on how to improve the definitaion of representative parameter values used for a parallel plate fracture model. Quantitative aperture distribution and quantitative tracer concentration data at each point in time were obtained by measuring the attenuation of transmitted light through the fracture in high spatial resolution. the representative aperture values evaluated from the multiple different measurement methods, such as arithmetic mean of aperture distribution measured by the optical method, transport aperture evaluated from the tracer test, and average aperture evaluated from the fracture void volume measurement converged to a unique value that indicates the accuracy of this experimental study. The aperture data was employed for verifying the numerical simulation under the assuption of Local Cubic Law and showed that the calculated flow rate through the fracture is 10%-100% larger than hydraulic test results. The quantitative tracer concentration data is also very valuable for validating existing numerical code for advection dispersion transport in-plane heterogeneous fractures.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.10
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• pp.1890-1896
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• 2008

In this paper, the Si vertical Hall devices ale fabricated by using standard bipolar process and investigated in terms of the opeating and noise properties. The sensitivity of device with P+ isolation dam(type B) has been increased up to about 1.2 times compared to that device without the dam also noise has been increased. With the condition of f=I[KHz], band-width 1[Hz], the resolution of magnetic-field detection were about $0.97[{\mu}T]$/ type B and $1.25[{\mu}T]$/ type A, respectively, thus we must consider correlation the low noise or good resolution and high sensitivity in the situation for device geometry design or even for the materials.

• Earthquakes and Structures
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• v.13 no.2
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• pp.119-130
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• 2017

This paper presents a numerical investigation on the seismic behavior of isolated bridges with supplemental viscous damping. Usually very large displacements make seismic isolation an unfeasible solution due to boundary conditions, especially in case of existing bridges or high risk seismic regions. First, a suggested optimal design procedure is introduced, then seismic performance of three real bridges with different isolation systems and damping levels is investigated. Each bridge is studied in four different configurations: simply supported (SSB), isolated with 10% damping (IB), isolated with 30% damping (LRB) and isolated with optimal supplemental damping ratio (IDB). Two of the case studies are investigated under spectrum compatible far-field ground motions, while the third one is subjected to near-fault strong motions. With respect to different design strategies proposed by other authors, results of the analysis demonstrated that an isolated bridge equipped with HDLRBs and a total equivalent damping ratio of 70% represents a very effective design solution. Thanks to confirmed effective performance in terms of base shear mitigation and displacement reduction under both far field and near fault ground motions, as well as for both simply supported and continuous bridges, the suggested control system provides robustness and reliability in terms of seismic performance also resulting cost effective.

• Quantitative Bio-Science
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• v.37 no.2
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• pp.125-132
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• 2018

In this study, noble strains of lactic acid bacteria were isolated and identified by genetic analysis of 16s rRNA. Also, pH-dependent growth curve, cholesterol assimilation ability and sugar production efficiency were measured. Lactic acid bacteria were identified to inhabit in the milks from various animals. Results of sequence analysis showed that there were differences in 16S rRNA sequence among strains and part of gene deletion was also recognized. Growth rates were varied, too, depending on the pH of the medium. Lactobacillus rhamnosus LOCK908 isolated from cow milk showed the highest growth rate and high cholesterol assimilation ability. Results of sugar fermentation tests were relatively consistent with the sequencing results. So, we propose newly isolated Lactobacillus rhamnosus LOCK908 as useful candidate for a starter of fermented beverage and probiotics. Results of this study will contribute to the isolation and identification of noble Lactic acid bacteria and to the public health.

• Fisheries and Aquatic Sciences
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• v.24 no.4
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• pp.163-170
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• 2021

Peptides are naturally occurring biological molecules that are found in all living organisms. These biologically active peptides play a key role in various biological processes. The aim of this study is the extraction and the purification of bioactive materials that induce relaxation of an apical muscle from the pyloric caeca of Patiria pectinifera. The acidified pyloric caeca extract was partially separated by the solid phase extraction using a stepwise gradient on Sep-Pak C18 cartridge. Among the fractions, materials eluted with 60% methanol/0.1% trifluoroacetic acid was put a thorough of a series of high performance liquid chromatography (HPLC) steps to isolate a neuropeptide with relaxation activity. The purified compound was eluted at 28% acetonitrile in 0.1% trifluoroacetic acid with retention time of 25.8 min on the CAPCELL-PAK C18 reversed-phase column. To determine the molecular weight and the amino acid sequence of the purified peptide, LC-MS and Edman degradation method were used, respectively. The primary structure of the peptide was determined to be FGMGGAYDPLSAGFTD which corresponded to the amino acid sequence of a starfish myorelaxant peptide (SMP) isotype (SMPb) found in the cDNA sequence encoding SMPa and its isotypes. In this study, a muscle relaxant neuropeptide (SMPb) has been isolated from pyloric caeca of starfish P. pectinifera. This is the first report of SMPb isolation on the protein level from P. pectinifera.