• Microbiology and Biotechnology Letters
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• v.46 no.1
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• pp.1-8
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• 2018

Gul (oyster) jeotgals (GJs) were prepared using different types of salt (23%, w/v): purified salt, solar salt aged for 3 years, and bamboo salt crystalized 3 times. One set of GJs was fermented with Bacillus subtilis JS2 ($10^6CFU/g$), while the other GJ set was fermented without starter. During fermentation for 24 weeks at $15^{\circ}C$, the starter GJs showed 10-fold higher bacilli counts than the no-starter GJs, where the maximum bacilli count was $8{\times}10^3CFU/g$. All 28 bacilli strains isolated from the 6-week GJs were identified as B. subtilis by using a RAPD-PCR, indicating that some of the B. subtilis JS2 cells remained viable. Lactic acid bacteria (LAB) and yeasts were present at low levels, $10^1-10^2CFU/g$. LAB with protease activities isolated from 10-week samples were identified as Enterococcus species. The isolates obtained at 16 weeks were all Staphylococcus species. The GJs with bamboo salt showed higher pH and lower titratable acidity (TA) values than the other GJs due to the strong alkalinity of bamboo salt. The amino-type nitrogen in the GJs increased slowly during the fermentation. At 24 weeks, the GJs with purified salt showed the highest amino-type nitrogen (412-430 mg%), followed by the GJs with solar salt (397-406 mg%) and GJs with bamboo salt (264-276 mg%). Meanwhile, the GJs with bamboo salt showed the highest ammonia-type N (63.67 mg%), followed by the GJs with purified salt (49 mg%) and solar salt (48 mg%).

• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.166-171
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• 2002

The genus Leuconostoc is generally recognized as a favorable microorganism associated with a good taste of Kimchi and Lactobacillus plantarum is responsible for the overripening and acidification of Kimchi. A rapid and reliable PCR-based method to monitor the change of these lactic acid bacterial populations during Kimchi fermentation was attempted. A Leuconostoc-specific primer set was chosen from the conserved sequences of 16S rRNA genes among Leuconostoc species. The Lb. plantarum-specific primer set was the internal segments of a Lb. plantarum-specific probe which was isolated after randomly amplified polymorphic DNA (RAPD) analysis and tested for identification. The specificity of this protocol was examined in DNA samples isolated from a single strain. In agarose gel, as little as 10 pg of template DNA could be used to visualize the PCR products, and quantitative determination was possible at the levels of 10 pg to 100 ng template DNA. For the semi-quantitative determination of microbial changes during Kimchi fermentation, total DNAs from the 2 h-cultured microflora of Kimchi were extracted for 16 days and equal amounts of DNA templates were used for PCR. The intensities of DNA bands obtained from PCR using Leuconostoc-specific and Lb. plantarum-specific primer sets marked a dramatic contrast at the 1 ng and 100 ng template DNA levels during Kimchi fermentation, respectively. As the fermentation proceeded, the intensity of the band for Leuconostoc species increased sharply until the 5th day and the levels was maintained until the 11 th day. The sharp increase for Lb. plantarum occurred after 11 days with the decrease of Leuconostoc species. The results of this study indicate that Leuconostoc species were the major microorganisms at the beginning of Kimchi fermentation and reach their highest population during the optimum ripening period of Kimchi.

• Journal of Communications and Networks
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• v.1 no.2
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• pp.89-98
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• 1999

In a synchronization (sync) $network^1$containing N nodes, it is shown (Theorem 1c) that an arbitrarily connected sync network & is the union of a countable set of isolated connecting sync networks${&_i,i= 1,2,.., L}, I.E., & = \bigcup_{I=1}^L&_i$ It is shown(Theorem 2e) that aconnecting sync network is the union of a set of disjoint irreducible subnetworks having one or more nodes. It is further shown(Theorem 3a) that there exists at least one closed irreducible subnetwork in $&_i$. It is further demonstrated that a con-necting sync network is the union of both a master group and a slave group of nodes. The master group is the union of closed irreducible subnetworks in $&_i$. The slave group is the union of non-colsed irre-ducible subnetworks in $&_i$. The relationships between master-slave(MS), mutual synchronous (MUS) and hierarchical MS/MUS ent-works are clearly manifested [1]. Additionally, Theorem 5 shows that each node in the slave group is accessible by at least on node in the master group. This allows one to conclude that the synchro-nization information avilable in the master group can be reliably transported to each node in the slave group. Counting and combinatorial arguments are used to develop a recursive algorithm which counts the number $A_N$ of arbitrarily connected sync network architectures in an N-nodal sync network and the number $C_N$ of isolated connecting sync network in &. EXamples for N=2,3,4,5 and 6 are provided. Finally, network examples are presented which illustrate the results offered by the theorems. The notation used and symbol definitions are listed in Appendix A.

• Smart Structures and Systems
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• v.29 no.1
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• pp.29-39
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• 2022

Crack detection plays an important role in the maintenance and protection of steel box girder of bridges. However, since the cracks only occupy an extremely small region of the high-resolution images captured from actual conditions, the existing methods cannot deal with this kind of image effectively. To solve this problem, this paper proposed a novel three-stage method based on deep learning technology and morphology operations. The training set and test set used in this paper are composed of 360 images (4928 × 3264 pixels) in steel girder box. The first stage of the proposed model converted high-resolution images into sub-images by using patch-based method and located the region of cracks by CBAM ResNet-50 model. The Recall reaches 0.95 on the test set. The second stage of our method uses the Attention U-Net model to get the accurate geometric edges of cracks based on results in the first stage. The IoU of the segmentation model implemented in this stage attains 0.48. In the third stage of the model, we remove the wrong-predicted isolated points in the predicted results through dilate operation and outlier elimination algorithm. The IoU of test set ascends to 0.70 after this stage. Ablation experiments are conducted to optimize the parameters and further promote the accuracy of the proposed method. The result shows that: (1) the best patch size of sub-images is 1024 × 1024. (2) the CBAM ResNet-50 and the Attention U-Net achieved the best results in the first and the second stage, respectively. (3) Pre-training the model of the first two stages can improve the IoU by 2.9%. In general, our method is of great significance for crack detection.

• The Journal of the Acoustical Society of Korea
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• v.14 no.4
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• pp.74-81
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• 1995

This paper describes the development of speech databases for the Korean language which were constructed at Communications Research Laboratory in KAIST. The procedure and environment to construct the speech database are presented in detail, and the phonetic and linguistic properties of the databases are presented. the databases were intended for use in designing and evaluating speech recognition algorithms. The databases consist of five different sets of speech contents : trade-related continuous speech with 3,000 words, variable-length connected digits, phoneme-balanced 75 isolated words, 500 isolated Korean provincial names, and Korean A-set words.

• Earthquakes and Structures
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• v.10 no.2
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• pp.293-311
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• 2016

A parametric study on the nonlinear seismic response of isolated reinforced concrete structural frame is presented. Three prototype frames designed according to the 1954 Hellenic seismic code, with number of floor ranging from 1 to 3 were considered. These low rise frames are representative of many existing reinforced concrete buildings in Greece. The efficacy of the implementation of both lead rubber bearings (LRB) and friction pendulum isolators (FPI) base isolation systems were examined. The selection of the isolation devices was made according to the ratio $T_{is}/T_{fb}$, where Tis is the period of the base isolation system and $T_{bf}$ is the period of the fixed-base building. The main purpose of this comprehensive study is to investigate the effect of the isolation system period on the seismic response of inadequately designed low rise buildings. Thus, the implementation of isolation systems which correspond to the ratio $T_{is}/T_{fb}$ that values from 3 to 5 is studied. Nonlinear time history analyses were performed to investigate the response of the isolated structures using a set of three natural seismic ground motions. The evaluation of each retrofitting case was made in terms of storey drift and storey shear force while in view of serviceability it was made in terms of storey acceleration. Finally, the maximum developed displacements and the residual displacements of the isolation systems are presented.

• The Plant Pathology Journal
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• v.18 no.2
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• pp.63-67
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• 2002

To understand plant-pathogen interactions, a complete set of hot pepper genes differentially expressed against pathogen attack was isolated. As an initial step, hundreds of differentially expressed cDNAS were isolated from hot pepper leaves showing non-host resistance against bacterial plant pathogens (Xanthomonas campestris pv. glycines and Pseudomonas syringae pv. syringae) using differential display reverse transcription polymerase chain reaction (DDDRT-PCR) technique. Reverse Northern and Northern blot analyses revealed that 50% of those genes were differentially expressed in pepper loaves during non-host resistance response. Among them, independent genes without redundancy were micro-arrayed for further analysis. Random EST sequence database were also generated from various CDNA libraries including pepper tissue specific libraries and leaves showing non-host hypersensitive response against X. campestris pv. glycines. As a primary stage, thousands of cDNA clones were sequenced and EST data were analyzed. These clones are being spotted on glass slide to study the expression profiling. Results of this study may further broaden knowledge on plant-pathogen interactions.

• Structural Engineering and Mechanics
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• v.29 no.6
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• pp.689-707
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• 2008

This study presents a method to evaluate the seismic risk of an extradosed bridge with seismic isolators of lead rubber bearings (LRBs), and also to show the effectiveness of the LRB isolators on the extradosed bridge, which is one of the relatively flexible and lightly damped structures in terms of seismic risk. Initially, the seismic vulnerability of a structure is evaluated, and then the seismic hazard of a specific site is rated using an earthquake data set and seismic hazard maps in Korea. Then, the seismic risk of the structure is assessed. The nonlinear seismic analyses are carried out to consider plastic deformation of bridge columns and the nonlinear characteristics of soil foundation. To describe the nonlinear behaviour of a column, the ductility demand is adopted, and the moment-curvature relation of a column is assumed to be bilinear hysteretic. The fragility curves are represented as a log-normal distribution function for column damage, movement of superstructure, and cable yielding. And the seismic hazard at a specific site is estimated using the available seismic hazard maps. The results show that in seismically-isolated extradosed bridges under earthquakes, the effectiveness of the isolators is much more noticeable in the columns than the cables and girders.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.3
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• pp.359-366
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• 2016

The health of Alaska pollock Theragra chalcogramma seedlings was monitored during February and April 2015. After microscopic examination for parasites, 20 samples sets were made by pooling 50 individuals for each sample set. Then, they were homogenized and examined for viral and bacterial pathogens. No parasites or viruses were detected using either microscopy or PCR. Colonies suspected of belonging to the genus Vibrio were isolated from Tryptic Soya Agar and Thiosulfate Citrate Bile Salts Sucrose Agar plate incubations, and identified as Vibrio anguillarum based on biochemical and physiological examinations and PCR amplification of the 16S rDNA, recA, and pyrH genes. Although there was no mortality during the sampling period, 65.0% (13/20) of the pooled samples were PCR-positive for V. anguillarum. To prevent possible outbreaks, the pathogenic potential of V. anguillarum should be investigated in the future.

• The Journal of the Acoustical Society of Korea
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• v.14 no.6
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• pp.54-61
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• 1995

In this paper, we implemented distributed neural network that recognizes phonemes by frame unit for the 30 Korean proverbs sentences consist of 106 isolated words. The features of speech were chosen as PLP cepstrums, energy and zero crossings, where we get those being used as inputs to the distributed neural networks in wide area for a frame to get the good temperal characteristics. A young man of twenties has produced 30 proverbs 5 times. The learning of neural network uses 4 sets of them. 1 set being unused remains for test. There exists silence between words for the easy discrimination. The ratio of frame recognition in large grouping neural network is $95.3\%$ when 4 sets were used for the learning.