• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.71-71
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• 2003

Hot embossing has been widely accepted as an alternative to photolithography in generating patterns on polymeric substrates. The optimization of embossing process should be accomplished based on polymer substrate materials. In this paper, the effect of polymer substrates on nano scale hot embossing process was studied. Silicon molds with nano size patterns were fabricated by e-beam direct writing. Molds were coated with self-assembled monolayer (SAM) of (1, 1, 2.2H -perfluorooctyl)-trichlorosilane to reduce the stiction between mold and substrates. For an embossing, pressure of 55, 75 bur, embossing time of 5 min and temperature of above transition temperature were peformed. Polymethylmethacrylates (PMMA) with different molecular weights of 450,000 and 950,000, MR-I 8010 polymer (Micro Resist Technology) and polyaliphatic imide copolymer were applied for hot embossing process development in nano size. These polymers were spun coated on the Si wafer with the thickness between 150 and 200 nm. The nano size patterns obtained after hot embossing were observed and compared based on the polymer properties by scanning electron microscopy (SEM). The imprinting uniformity dependent on the Pattern density and size was investigated. Four polymers have been evaluated for the nanoimprint By optimizing the process parameters, the four polymers lead to uniform imprint and good pattern profiles. A reduction in the friction for smooth surfaces during demoulding is possible by polymer selection.

• Genomics & Informatics
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• v.5 no.4
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• pp.152-160
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• 2007

Most common diseases are caused by multiple genetic and environmental factors. Among the genetic factors, single nucleotide polymorphisms (SNPs) are common DNA sequence variations in individuals and can serve as important genetic markers. Recently, investigations of gene-based and whole genome-based SNPs have been applied to association studies for marker discovery. However, SNPs are so population-specific that the association needs to be verified. Fifty-five genes and 384 SNPs were selected based on association with disease. Genotypes of 337 SNPs in candidate genes were determined using Illumina Sentrix Array Matrix (SAM) chips by an allele-specific extension method in 364 unrelated Korean individuals. Allelic frequencies of SNPs were compared with those of other populations obtained from the International HapMap database. Minor allele frequencies, linkage disequilibrium blocks, tagSNPs, and haplotypes of functional candidate SNPs in 55 genetic disease-associated genes were provided. Our data may provide useful information for the selection of genetic markers for gene-based genetic disease-association studies of the Korean population.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.6
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• pp.468-474
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• 1990

Eight species, 6 Dinophyceae and 2 Raphidophyceae, caused a bloom in the southeastern coastal waters mainly in Chinhae Bay in Korea from March to September since 1982. Scrippsiella trochoidea and Heterocapsa triquetra bloomed in March then ensued a vernal species Heterosigma akashiwo. And Cochlodinium sp. and Alexandrium affine were occurred as causative organism in fall next to the estival dinoflagellates Gyrodinium instriatum and Pheopolykrikos hartmannii. Among them, spatio-temporal similarity of outbreak was significant in Heterosigma akashiwo since 1983, and a bit apparent for Cochlodinium sp.. The density was in the level from $10^3\;to\;10^5\;cells/ml$ and was dependent on the cell size rather than environmental characteristics.

• Tunnel and Underground Space
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• v.15 no.4 s.57
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• pp.305-315
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• 2005

DDA (Discontinuous Deformation Anlaysis) is one of the latest numerical analysis which has merits of both FEM and DEM. In this research a new edge-to-edge contact algorithm was applied on DDA. With adoption of new edge-to-edge contact state definition, sub-algorithm was improved about open-close iteration, contact state judge, contact detecting, and friction forces acting on joints. Newly applied DDA was verified based on two different cases. The DDA results show good agreement with numerically predicted one.

• Nuclear Engineering and Technology
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• v.37 no.5
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• pp.503-510
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• 2005

An instrumental neutron activation analysis was used to measure the concentrations of about 24 elements associated with airborne particulates (PM10) that were collected in the most polluted urban region of Daejeon city, Korea from 2000 to 2002. Using the measurement data for various elements, both the extent of elemental pollution in the study area and the seasonality in their distribution characteristics were examined. Examinations of their distribution patterns indicated that most elements with crustal origin tend to exhibit seasonal peaks during spring, while most elements with anthropogenic origin tend to exhibit seasonal peaks during fall or winter. In order to explain the factors regulating their mobilization properties, the data were processed by a factor analysis. Results of the factor analysis suggested competing roles of both industrial and natural source processes, despite that the study site is located at a downwind position of the industrial complex. Based on the overall results of this study, it is concluded that the site may be strongly impacted by man-made sources but the general patterns of elemental distributions in the study area inspected over a seasonal scale are quite consistent with those typically observed from natural environment.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.244-244
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• 1994

Cortex Mori, the root bark of mulbery tree has been used as an antiphlogistic, diuretic, and expectorant in herbal medicine. The purpose of this study is to evaluate chicken gamma globulin (CGG)-specific IgE-induced morphologic and functional changes in rat peritoneal mast cells (RPMC), and to determine whether Cortex Mori could inhibit the CGG-specific IgE-depeildent mast cell degranulation and histamine release from RPMC. Results are 1) the degranuration and histamine release from RPMC were not induced within 1 hour after addition of Cortex Mori alone, 2) the CGG and CGG-specific IgE-Induced degranulation from RPMC was observed within 10 minutes, 3) the histamine release from RPMC sensitised with CGG-specific IgE was induced by tile addition of CGG, 4) CGG-specific IgE-dependent degranulation rate in RPMC pretreated with Cortex Mori was significantly Inhibited, compared to that of control group without Cortex Mori pretreatment, and 5) the CGG-specific IgE-dependent histamine release from RPMC was significantly inhibited by pretreatment with Cortex Mori. These data suggest that Cortex Mori contains some substances with capabilities to inhibit CGG-specific IgE-dependent degranulation and histamine release from RPMC.

• Journal of Ocean Engineering and Technology
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• v.23 no.6
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• pp.99-104
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• 2009

PTFE has good mechanical and chemical stability at a wide range of temperatures and demonstrates a low friction coefficient value. PTFE is being used for self-lubricating parts in industry. But it shows a high wear rate. Thus, PTFE and nano-diamond powder were mixed into a composite and the wear properties of a PTFE coating layer on Al6061 was investigated. A ball-on-disk type of wear tester was used under a dry condition and different temperatures of oil. After the wear test, the wear track wasexamined by optical microscope. The PTFE-diamond showed the lowest friction coefficient (0.02) of all the lubricants in the experiments. The friction coefficient was shown to be directly related to the diamond powder in the PTFE coating. Adhesion estimations were performed by a scratch test, which is mainly used for coatings. The critical load between the coating and substrate was defined through analyses of the friction load, normal load curve, and acoustic emissions, along with optical microscope observations. The scratch test results showed that an import item (SWISS) gave the highest critical load values.

• Journal of Environmental Science International
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• v.15 no.7
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• pp.695-699
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• 2006

This study is to investigate the relationship between pore structures of activated carbons and adsorption characteristics of toluene vapor using dynamic adsorption method. The surface areas of below $10{\AA}$ in the pore diameter of activated carbons used in this experiment were in the range of 72 -93 % of total cumulative surface area and the toluene vapor equilibrium adsorption capacities were in the range of 350 - 390mg/g. Activated carbons having larger toluene adsorption capacity than the compared activated carbons had relatively pores in the pore diameter range of $7-10{\AA}$. Linear relationship between equilibrium adsorption capacity and cumulative sur- face area was in the diameter range of over $7{\AA}$. It was thought that toluene vapor was relatively well adsorbed on surfaces of pores of over $7{\AA}$.

• Journal of Korean Institute of Industrial Engineers
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• v.2 no.1
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• pp.37-44
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• 1976

It is necessary for developing countries to increase their consolidation of domestic technology in order to improve their economy. In order to raise their techniques, they have to try to induce the advanced know-how from other countries in spite of heavy cost. The object of this study is to establish the model on which we base our choice of the proper techniques or plants and give priority to them by using quantified selection criteria. The method in this study has two stages, and the writer has selected 12 factors affecting the decision making for the importation of technology from the industrially advanced countries. First, the lists of valuable know-how for the better development of national industry should be determined, and for the formulation and arrangement of the lists, a council of specialists which uses questionnaires in terms of the Semantic Differential Method, should be organized. Second, for the assignments of priority to the prospective items for importation, the writer has imployed both the Leontief Model and the Disman Model as objective methods and Mottley-Newton method, one of the R&D Project Selection Methods, as a general model. The writer has applied the methods described above to the fields of petrochemical industry in Korea.

• Journal of Korea Multimedia Society
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• v.7 no.10
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• pp.1412-1420
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• 2004

This thesis is dealing with conveyer remote monitoring and control system for shoes process formed by client/server, which is based on Web. Modules for watching and controlling images in a remote by client is manufactured under JAVA, and conveyer server for real-time controlling is founded on RTLinux. And device driver and APIs are developed based on it. Through both manufacturing these software and LEGO-based prototyping, it would present the real-time conveyer controlling system founded on Web and 3-dimensional stereo camera to be applied to industrial spots.