• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.576-582
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• 2002

Probiotics are live microbial feed supplements which beneficially affect the host animal by improving its intestinal microflora. To select the best Lactobacillus spp. as a chicken probiotic, probiotic characteristics of 10 selected Lactobacillus strains isolated from chicken cecum or obtained from KCTC were investigated. The strains were examined for resistance to pH 2.0 and 0.3% oxgall, and adhesion to cecal mucus and cecal epithelial cells. All strains grew in MRS containing 0.3% oxgall. However, Lb. plantarum AYM-10, Lb. fermentum YL-3, AYM-3, and Lb. paracasei YL-6 showed relatively high resistance to 0.3% oxgall. Lb. fermentum YL-3, YM-5, AYM-3, and Lb. paracasei YL-6 survived 4 hours of incubation at pH 2.0. Lb. fermentum YL-3, KCTC 3112, and Lb. plantarum AYL-5 were strongly adhesive to cecal mucus, while the rest showed moderate or low adhesion. Lb. plantarum AYM-10, AYL-1, and AYL-5 had good adhering properties to cecal epithelial cells (30.7$\pm$10.82, 40.2$\pm$20.90, and 14.5$\pm$4.22, respectively). Lb. fermentum YL-3, AYM-3, and KCTC 3547 showed Intermediate adhesion ability, and Lb. plantarum showed better adhesion ability to cecal epithelial cells than Lb. fermentum. Attached Lb. fermentum YL-3 to cecum after 60 min incubation was confirmed using CLSM. Lb. fermentum YL-3 attached to a matrix which was composed of a mucus layer adjacent to intracrypts and pericryptal region. Some Lb. fermentum YL-3 bound to mucosal epithelial cells. From these results, Lb. fermentum YL-3 was selected as a chicken probiotic. In vivo trials of chicks inoculated with Lb. fermentum YL-3 had decreased Salmonella population in cecal contents and livers (p<0.5).

• Bioinformatics and Biosystems
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• v.1 no.1
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• pp.67-72
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• 2006

The aim of this paper is to discuss the effect of missing values in detecting differentially expressed genes in a cDNA microarray experiment in the context of a one sample problem. We conducted a cDNA micro array experiment to detect differentially expressed genes for the metastasis of colorectal cancer based on twenty patients who underwent liver resection due to liver metastasis from colorectal cancer. Total RNAs from metastatic liver tumor and adjacent normal liver tissue from a single patient were labeled with cy5 and cy3, respectively, and competitively hybridized to a cDNA microarray with 7775 human genes. We used $M=log_2(R/G)$ for the signal evaluation, where Rand G denoted the fluorescent intensities of Cy5 and Cy3 dyes, respectively. The statistical problem comprises a one sample test of testing E(M)=0 for each gene and involves multiple tests. The twenty cDNA microarray data would comprise a matrix of dimension 7775 by 20, if there were no missing values. However, missing values occur for various reasons. For each gene, the no missing proportion (NMP) was defined to be the proportion of non-missing values out of twenty. In detecting differentially expressed (DE) genes, we used the genes whose NMP is greater than or equal to 0.4 and then sequentially increased NMP by 0.1 for investigating its effect on the detection of DE genes. For each fixed NMP, we imputed the missing values with K-nearest neighbor method (K=10) and applied the nonparametric t-test of Dudoit et al. (2002), SAM by Tusher et al. (2001) and empirical Bayes procedure by $L\ddot{o}nnstedt$ and Speed (2002) to find out the effect of missing values in the final outcome. These three procedures yielded substantially agreeable result in detecting DE genes. Of these three procedures we used SAM for exploring the acceptable NMP level. The result showed that the optimum no missing proportion (NMP) found in this data set turned out to be 80%. It is more desirable to find the optimum level of NMP for each data set by applying the method described in this note, when the plot of (NMP, Number of overlapping genes) shows a turning point.

• The KIPS Transactions:PartD
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• v.9D no.5
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• pp.779-788
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• 2002

There are many technically difficult issues in searching multimedia data such as image, video and audio because they are massive and more complex than simple text-based data. As a method of searching multimedia data, a similarity retrieval has been studied to retrieve automatically basic features of multimedia data and to make a search among data with retrieved features because exact match is not adaptable to a matrix of features of multimedia. In this paper, data clustering and its indexing are proposed as a speedy similarity-retrieval method of multimedia data. This approach clusters similar images on adjacent disk cylinders and then builds Indexes to access the clusters. To minimize the search cost, the hashing is adapted to index cluster. In addition, to reduce I/O time, the proposed searching takes just one I/O to look up the location of the cluster containing similar object and one sequential file I/O to read in this cluster. The proposed schema solves the problem of multi-dimension by using clustering and its indexing and has higher search efficiency than the content-based image retrieval that uses only clustering or indexing structure.

• KIEAE Journal
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• v.16 no.1
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• pp.89-94
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• 2016

This study is part of three-dimensional(3D) heat transfer analysis program developmental process. The program is being developed without it's own built in 3D-modeller. So 3D-model must be created from another 3D-modeller such as generic CAD programs and imported to the developed program. After that, according to the 3D-geometric data form imported model, 3D-mesh created for numerical calculation. But the 3D-model created from another 3D-modeller is likely to have errors in it's geometric data such as mismatch of position between vertexes or surfaces. these errors make it difficult to create 3D-mesh for calculation. These errors are must be detected and cured in the pre-process before creating 3D-mesh. So, in this study four kinds of filters and functions are developed and tested. Firstly, 'vertex error filter' is developed for detecting and curing for position data errors between vertexes. Secondly, 'normal vector error filter' is developed for errors of surface's normal vector in 3D-model. Thirdly, 'intersection filter' is developed for extracting and creating intersection surface between adjacent objects. fourthly, 'polygon-line filter' is developed for indicating outlines of object in 3D-model. the developed filters and functions were tested on several shapes of 3D-models. and confirmed applicability. these developed filters and functions will be applied to the developed program and tested and modified continuously for less errors and more accuracy.

• Journal of the Korean Geotechnical Society
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• v.29 no.8
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• pp.65-73
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• 2013

Ground-coupled heat pump system has attracted attention as a promising renewable energy technology due to its improving energy efficiency and eco-friendly mechanism for space cooling and heating. Pipes buried in the ground play a role of direct thermal interaction between circulating fluid inside the pipe and surrounding soils in the geothermal exchange system. However, both complexities of turbulent flow coupling thermal-hydraulic phenomena and very long aspect ratio of the pipe make it difficult to model the heat exchange system directly. Energy balance for fluid flow inside the pipe was derived to model thermal-hydraulic phenomena, and one-dimensional pipe element was proposed through Galerkin formation and time integration of the equation. Developed element is combined to pre-developed FEM code for THM phenomena in porous media. Numerical results of Thermal Response Test showed that line-source model overestimates equivalent thermal conductivity of surrounding soils due to thermal interaction between adjacent pipes and finite length of the pipe. Thus, inverse analysis for the TRT simulation was conducted to present optimal transformation matrix with utmost convergence.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.180-185
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• 2001

In the life assessment for plant structural component, the research on deterioration of toughness and material properties occurred in weldments has been considered as very important problems. In general, the microstructures composed in weldments are hugely classified with weld metal(W.M), fusion line(F.L), heat affected zone(HAZ), and base metal(B.M). It has been reported that the creep characteristics on weldments having variable microstructures could be unpredictably changed. Furthermore, it is also known that HAZ adjacent to F.L exhibits the decreased creep strength compared to those in base or weld metals, and promotes the occurrence of Type III and Type IV cracking due to the growth of grains and the coarsening carbides precipitated in ferritic matrix by welding and PWHT processes. However, the lots of works reported up to date on creep damage in power plant components have been mostly conducted on B.M and the creep properties on a localized microstructures in weldments have not as yet been throughly investigated. In this paper, for various microstructures such as coarse grain HAZ(CGHAZ), W.M and B.M in X20CrMoV121 steel weldment, the small punch-creep(SP-Creep) test using miniaturized specimen(t=0.5mm, 0.25mm) is performed to investigate a possibility for creep characteristics evaluation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.6
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• pp.629-633
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• 2011

Recently, systems such as aircraft, trains and ships have become larger more complex. Therefore, the reliability calculation of these systems is more difficult. This paper presents a reliability calculation algorithm for a complex system with a solution that is difficult to analyze. When the system has a very complex structure, it is very difficult to find an analytical solution. In this case, we can assess system reliability using the failure enumeration method of the reliability path. In this research, we represent the reliability block diagram by an adjacent matrix and define the reliability path. We can find any system status by the failure enumeration of the reliability path, and thus we can calculate any kind of system reliability through this process. This result can be applied to RCM (Reliability-Centered Maintenance) and reliability information-management systems, in which the system reliability is composed of the reliabilities of individual parts.

• Journal of IKEEE
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• v.11 no.4
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• pp.187-192
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• 2007

Since wireless sensor networks (WSN) have relatively narrow bandwidth and have limited memory space. Mosaic by inlaying images transmitted by adjacent sensors can provide wider field of view and smaller storage memory. Most WSN are used for surveillance purpose, image acquisition period should be sufficiently short, so that mosaic algorithm has to be run in real time. Proposed algorithm is derived by using the fact that position of sensor nodes are fixed and known. Transformation matrix can be calculated by using distance between sensor nodes and distance between sensor nodes and predefined object. Simulation result shows that proposed algorithm provides very short processing time whereas it preserves image quality.

• Journal of the Korea Society of Computer and Information
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• v.20 no.4
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• pp.111-117
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• 2015

The exam scheduling problem has been classified as nondeterministic polynomial time-complete (NP-complete) problem because of the polynomial time algorithm to obtain the exact solution has been unknown yet. Gu${\acute{e}}$ret et al. tries to obtain the solution using linear programming with $O(m^4)$ time complexity for this problem. On the other hand, this paper suggests chromatic number algorithm with O(m) time complexity. The proposed algorithm converts the original data to incompatibility matrix for modules and graph firstly. Then, this algorithm packs the minimum degree vertex (module) and not adjacent vertex to this vertex into the bin $B_i$ with color $C_i$ in order to exam within minimum time period and meet the incompatibility constraints. As a result of experiments, this algorithm reduces the $O(m^4)$ of linear programming to O(m) time complexity for exam scheduling problem, and gets the same solution with linear programming.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.1
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• pp.131-145
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• 2013

The purposes of this research are : to analyze biotop type and carry out conservation value assessment in study areas, Daegu Science Park national industrial complex; to supply basic data for the landscape ecological planning; and to improve the application of assessment model with the development of Biotop Value Assessment Tool (B-VAT). The result is as follows. First of all, the field survey showed 434 species of flora and 220 species of insecta. According to the result of biotop type analysis in the biotop classification system with field survey, 13 biotope groups and 63 biotope types were classified. In the map of biotop type classification, readjusted farmland biotop(FA) was prevalent and forest biotop(E) was shown to the southeast side of the site. Next, according to the first assessment with B-VAT, total 19 biotop types including natural river(BA) with abundant plants had I grade and total 16 biotop types such as vegetable garden adjacent to river(BC) had V grade. In terms of the second assessment, we analyzed total 30 areas, total 82 areas, respectively, which had special meaning for the conservation of species and biotop(1a, 1b) and which had meaning for the conservation of species and biotop(2a, 2b, 2c). This research will be a basic data, which can solve the damage problem systematically and control it landscape-friendly with biotop classification and assessment which we developed. In particular, we expect that biotop value assessment tool(B-VAT) with GIS will be a great contribution to popularity compared with the value model by complicated algorism such as adding-matrix, weight and equal distribution. In addition, this will save the time and improve the accuracy for hand-counting.