• Journal of Microbiology and Biotechnology
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• v.27 no.9
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• pp.1701-1710
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• 2017

Classical swine fever virus (CSFV) is the etiologic agent of classical swine fever, a highly contagious disease that causes significant economic losses to the swine industry. The lapinized C-strain, a widely used vaccine strain against CSFV, has low growth efficiency in cell culture, which limits the productivity in the vaccine industry. In this study, a recombinant virus derived from C-strain was constructed and subjected to continuous passaging in PK-15 cells with the goal of acquiring a high progeny virus yield. A cell-adapted virus variant, RecCpp80, had nearly 1,000-fold higher titer than its parent C-strain but lost the ability to induce fever in rabbits. Sequence analysis of cell-adapted RecC variants indicated that at least six nucleotide changes were fixed in RecCpp80. Further adaption of RecCpp80 variant in swine testicle cells led to a higher virus yield without additional mutations. Introduction of each of these residues into the wild-type RecC backbone showed that one mutation, M979R (T3310G), located in the C-terminal region of E2 might be closely related to the cell-adapted phenotype. Rabbit inoculation revealed that $RecCpp40_{+10}$ failed to induce fever in rabbits, whereas $RecCpp80_{+10}$ caused a fever response similar to the commercial C-strain vaccine. In conclusion, the C-strain can be adapted to cell culture by introducing specific mutations in its E2 protein. The mutations in RecCpp80 that led to the loss of fever response in rabbits require further investigation. Continuous passaging of the C-strain-based recombinant viruses in PK-15 cells could enhance its in vitro adaption. The non-synonymous mutations at 3310 and 3531 might play major roles in the enhanced capacity of general virus reproduction. Such findings may help design a modified C-strain for improved productivity of commercial vaccines at reduced production cost.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.11
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• pp.2075-2082
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• 2006

This paper presents modeling and optimization techniques for hish efficiency solar cell process on single-crystalline float zone (FZ) wafers. Among a sequence of multiple steps of fabrication, the followings are the most sensitive steps for the contact formation: 1) Emitter formation by diffusion; 2) Anti-reflection-coating (ARC) with silicon nitride using plasma-enhanced chemical vapor deposition (PECVD); 3) Screen-printing for front and back metalization; and 4) Contact formation by firing. In order to increase the performance of solar cells in terms of efficiency, the contact formation process is modeled and optimized using neural networks and genetic algorithms, respectively. This paper utilizes the design of experiments (DOE) in contact formation to reduce process time and fabrication costs. The experiments were designed by using central composite design which consists of 24 factorial design augmented by 8 axial points with three center points. After contact formation process, the efficiency of the fabricated solar cell is modeled using neural networks. Established efficiency model is then used for the analysis of the process characteristics and process optimization for more efficient solar cell fabrication.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.7
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• pp.1393-1398
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• 2009

Conventionally, etching is first considered for microelectronics fabrication process and is specially important in process of a-Si:H thin film transistor for LCD. In this paper, we stabilize properties of device by development of wet and dry etching process. The a-Si:H TFTs of this paper is inverted staggered type. The gate electrode is lower part. The gate electrode is formed by patterning with length of 8 ${\mu}$m${\sim}$16 ${\mu}$m and width of 80${\sim}$200 ${\mu}$m after depositing with gate electrode (Cr) 1500 ${\AA}$under coming 7059 glass substrate. We have fabricated a-SiN:H, conductor, etch-stopper and photo resistor on gate electrode in sequence, respectively. The thickness of these thin films is formed with a-SiN:H (2000 ${\mu}$m), a-Si:H(2000 ${\mu}$m) and n+a-Si:H (500 ${\mu}$m), We have deposited n-a-Si:H, NPR(Negative Photo Resister) layer after forming pattern of Cr gate electrode by etch-stopper pattern. The NPR layer by inverting pattern of upper gate electrode is patterned and the n+a-Si:H layer is etched by the NPR pattern. The NPR layer is removed. After Cr layer is deposited and patterned, the source-drain electrode is formed. In the fabricated TFT, the most frequent problems are over and under etching in etching process. We were able to improve properties of device by strict criterion on wet, dry etching and cleaning process.

• Journal of KIISE:Software and Applications
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• v.29 no.1_2
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• pp.42-52
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• 2002

Information extraction(IE) is a process of recognizing and fetching particular information fragments from a document. In previous work, most IE systems generate the extraction rules called the wrappers manually, and although this manual wrapper generation may achieve more correct extraction, it reveals some problems in flexibility, extensibility, and efficiency. Some other researches that employ automatic ways of generating wrappers are also experiencing difficulties in acquiring and representing useful domain knowledge and in coping with the structural heterogeneity among different information sources, and as a result, the real-world information sources with complex document structures could not be correctly analyzed. In order to resolve these problems, this paper presents an agent-based information extraction system named XTROS that exploits the domain knowledge to learn from documents in a semi-structured information source. This system generates a wrapper for each information source automatically and performs information extraction and information integration by applying this wrapper to the corresponding source. In XTROS, both the domain knowledge and the wrapper are represented as XML-type documents. The wrapper generation algorithm first recognizes the meaning of each logical line of a sample document by using the domain knowledge, and then finds the most frequent pattern from the sequence of semantic representations of the logical lines. Eventually, the location and the structure of this pattern represented by an XML document becomes the wrapper. By testing XTROS on several real-estate information sites, we claim that it creates the correct wrappers for most Web sources and consequently facilitates effective information extraction and integration for heterogeneous and complex information sources.

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.191-197
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• 2013

Two medium-leaf ecotypes (CY6069, CY6097) belonging to one species (Zoysia japonica) of Korean lawngrasses were selected in sod production fields in Jang Seong, Korea. They were reported to have distinct morphological and growth rate characteristics different from the preferred medium-leaf type zoysiagrass in Korea. This study was conducted to define further the genotypic difference at the molecular level and to develop DNA marker based on the specific DNA fragment. Polymorphic DNA fragments were first explored by using randomly amplified polymorphic DNA (RAPD) primers, which were then converted into PCR-based sequence characterized amplified region (SCAR) markers. The CY6069-specific primer set amplified about 550 bp successfully, while the CY6097 marker produced the expected 690 bp band, by which those markers were nominated by CY6069_550 and CY6069_690 SCARs, respectively. Together with the reported morphological and other phenotypic features, the SCAR markers confirmed in this study will be useful to identify those medium-leaf zoysiagrass genotypes when they are cultivated with other vegetatively propagated warm-season turfgrasses in sod farms.

• Korean Journal of Materials Research
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• v.22 no.7
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• pp.379-383
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• 2012

$TiO_2$ thin films consisting of positively charged poly(diallyldimethylammonium chloride)(PDDA) and negatively charged titanium(IV) bis(ammonium lactato) dihydroxide(TALH) were successfully fabricated on glass beads by a layer-by-layer(LBL) self-assembly method. The glass beads used here showed a positive charge in an acid range and negative charge in an alkaline range. The glass beads coated with the coating sequence of(PDDA/TALH)n showed a change in the surface morphology as a function of the number of bilayers. When the number of bilayers(n) of the(PDDA/TALH) thin film was 20, Ti element was observed on the surface of the coated glass beads. The thin films coated onto the glass beads had a main peak of the (101) crystal face and were highly crystallized with XRD diffraction peaks of anatase-type $TiO_2$ according to an XRD analysis. In addition, the $TiO_2$ thin films showed photocatalytic properties such that they could decompose a methyl orange solution under illumination with UV light. As the number of bilayers of the(PDDA/TALH) thin film increased, the photocatalytic property of the $TiO_2$-coated glass beads increased with the increase in the thin film thickness. The surface morphologies and optical properties of glass beads coated with $TiO_2$ thin films with different coating numbers were measured by field emission scanning electron microscopy(FE-SEM), X-ray diffraction(XRD) and by UV-Vis spectrophotometry(UV-vis).

• Journal of Internet Computing and Services
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• v.10 no.2
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• pp.1-13
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• 2009

Intrusion detection is a process that identifies the attacks and responds to the malicious intrusion actions for the protection of the computer and the network resources. Due to the fast development of the Internet, the types of intrusions become more complex recently and need immediate and correct responses because the frequent occurrences of a new intrusion type rise rapidly. Therefore, to solve these problems of the intrusion detection systems, we propose a sequential pattern miner for analysis of the alert data in order to support intelligent and automatic detection of the intrusion. Sequential pattern mining is one of the methods to find the patterns among the extracted items that are frequent in the fixed sequences. We apply the prefixSpan algorithm to find out the alert sequences. This method can be used to predict the actions of the sequential patterns and to create the rules of the intrusions. In this paper, we propose an extended prefixSpan algorithm which is designed to consider the specific characteristics of the alert data. The extended sequential pattern miner will be used as a part of alert data analyzer of intrusion detection systems. By using the created rules from the sequential pattern miner, the HA(high-level alert analyzer) of PEP(policy enforcement point), usually called IDS, performs the prediction of the sequence behaviors and changing patterns that were not visibly checked.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.6
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• pp.1099-1103
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• 2007

TFT's have been intensively researched for possible electronic and display applications. Through tremendous engineering and scientific efforts, a-Si:H TFT fabrication process was greatly improved. In this paper, the reason on defects occurring at a-Si:H TFT fabrication process is analyzed and solved, so a-Si:H TFT's yield is increased and reliability is improved. The a-Si:H TFT of this paper is inverted staggered type TFT. The gate electrode is formed by patterning with length of $8{\mu}m{\sim}16{\mu}m$ and width of $80{\sim}200{\mu}m$ after depositing with gate electrode (Cr). We have fabricated a-SiN:H, conductor, etch-stopper and photo-resistor on gate electrode in sequence, respectively. We have deposited n+a-Si:H, NPR(Negative Photo Resister) layer after forming pattern of Cr gate electrode by etch-slower pattern. The NPR layer by inverting pattern of upper Sate electrode is patterned and the n+a-Si:H layer is etched by the NPR pattern. The NPR layer is removed. After Cr layer is deposited and patterned, the source-drain electrode is formed. The a-Si:H TFT made like this has problems at photo-lithography process caused by remains of PR. When sample is cleaned, this remains of PR makes thin chemical film on surface and damages device. Therefor, in order to improve this problem we added ashing process and cleaning process was enforced strictly. We can estimate that this method stabilizes fabrication process and makes to increase a-Si:H TFT's yield.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.369-376
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• 2009

Cowpea might have been introduced from China to Korea and cultivated for several hundred years but it has never been a staple food crop in Korea. In this study, genetic diversity of 492 Korean cowpea landrace accessions that have passport information was estimated using six SSR markers. The mean of Weir's gene diversity was 0.665 from all accessions investigated in the study. Cowpea gene diversity of six local provinces in Korea was ranged from 0.370 in accessions of Gangwon to 0.680 in Jeonra provinces. Low gene diversity of the cowpea genepool of Gangwon province was probably derived from relatively few introductions. Especially SSR markers VM36 and VM39 seem to be good markers to distinguish the Gangwon accessions from others by occurring at a specific locus with higher than 78% of allele frequency. Except for the Gangwon province with the low genetic diversity, gene diversity of cowpea accessions from other provinces was ranged from 0.600 to 0.680 indicating no big differences among provinces. Distribution pattern of the allele frequencies was similar among the other provinces. This may reveal that Korean farmers might exchange cowpea seeds easily with even their neighbors with geographical barriers. A core collection, 100 landraces, ca. 20% of base collection, was developed at the 70% of a similarity coefficient level using random sampling approaches after stratification of the entire landrace collection based on the phenetic dendrogram. The variability of SSR in the base and core collections of Korean cowpea landrace was compared by calculating Weir's gene diversity. The mean of Weir's gene diversity of the core was 0.707 while that of the base collection was 0.665. The higher diversity index in the core collection indicates that it maintains the initial variability and well represents the base collection. The core collection included one of determinate accession (IT 216155) and two of no branching type accessions (IT 103959 and IT 161024). The core collection could be used to guide more efficient management and utilization of the entire collection. This core collection should be revised periodically as additional accessions are collected and further characterization is conducted.

• Korean Journal of Plant Taxonomy
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• v.39 no.2
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• pp.63-73
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• 2009

$Iso{\ddot{e}}tes$ L. ($Iso{\ddot{e}}taceae$) is difficult to identify among the infrageneric taxa because of morphological simplicity. Since two species (I. japonica and I. coreana) had been reported, I. jejuensis and I. hallasanensis were described as two new species from Jeju Island, South Korea. The habitats of all species were confirmed by current studies except for I. japonica. We compared the morphological and anatomical characters of seven species, three domestic species and four species in adjacent regions (I. taiwanensis, I. sinensis, I. japonica, and I. asiatica). I. asiatica differs from other species in the lobe number of corm, spreading sporophylls, lack of stomata and degree of velum development. All of the seven species were identified by the characteristics of their mega- and microspores. Especially, it was possible to identify the four species in South Korea by the types of ornamentation on their megaspores. Each species has a specific type of megaspore ornamentation: I. coreana - cristate, I. jejuensis - rugulate, I. hallasanensis - echinate, and I. japonica - reticulate. We also discussed the phylogeny of the genus in East Asia in relation to recent studies based on the second intron of LEAFY sequence and amplified fragment length polymorphism (AFLP) analysis. We suggest strategies for the conservation of the endangered $Iso{\ddot{e}}tes$ species in South Korea.