• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.53-56
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• 2006

This paper describes performance design of a solid rocket motor on which thrust cut-off system is installed, and evaluates performance of a rocket motor according to a size of TCO ports. TCO system installed on motors was made to carry out firing tests, and the trend of thrust due to various sizes of TCO port was analyzed to find the existence of the port size for maximum reversal thrust. Conservation equations were used to design performance of motors and to analyze test results. This technique for performance design will be usefully applied to the design of similar TCO systems.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.5
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• pp.101-106
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• 2006

This paper describes performance design of a solid rocket motor on which thrust cut-off system is installed, and evaluates performance of a rocket motor according to a size of TCO ports. TCO system installed on motors was made to carry out firing tests, and the trend of thrust due to various sizes of TCO port was analyzed to find the existence of the port size for maximum reversal thrust. Conservation equations were used to design performance of motors and to analyze test results. This technique for performance design will be usefully applied to the design of similar TCO systems.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.11
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• pp.961-968
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• 2009

In this work, transparent conductive oxide(TCO) films such as $In_2O_3-SnO_2$(ITO) and $In_2O_3-ZnO$(IZO) were prepared on polyethylene naphthalene(PEN) and glass substrates by using rf-magnetron sputtering system. The TCO films deposited on PEN substrate show very poor conductivity as compared to that of the TCO films deposited on glass substrates. From the results of the residual gas analysis(RGA) test, this poor stability of plastic substrate is presumed to be caused by the deteriorated adhesion between the TCO films and the plastic substrate due to outgassing from the plastic substrate during deposition of TCO films. From our experiment, it is found that the vaporization of some defects in the plastic substrates deteriorate the adhesion of the TCO films to the plastic substrate, because the most plastic substrates containing the water vapor and/or other adsorbed particles such as organic solvents. Mixing of these gases vaporized in the sputtering process will also affect the electrical property of the deposited TCO films. Inorganic thin composite $(SiO_2)_{40}(ZnO)_{60}$ film as a gas barrier layer is coated on the PEN substrate to protecting the diffusion of vapors from the substrate, so that the TCO films with an improved quality can be obtained.

• Journal of Digital Convergence
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• v.8 no.4
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• pp.185-204
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• 2010

This case study quantifies the savings that can be realized through integration in National Computing & Information Agency (NCIA) of the Korea Government. It is based on the process of the NCIA development project that consolidating and integrating distributed 24 agencies. And it used the widely accepted Gartner TCO (Total Cost of Ownership) Solution and applies that methodology consistently before and after integration. Specific measurement items for examining the information system integration saving cost are developed pilot test for 2 agencies through compare TCO before integration and TCO after integration. The results of measuring on information system integration in NCIA are showed lots of economic cost reduction in TCO by integrating and consolidating each computing environment in agency. Especially in detail, NCIA realized the most savings in IT Capital Cost including development of hardware, software and recovery system. Also IT Support Cost and IT Administration Cost examined more savings than before IT integration.

• 한국균학회소식:학술대회논문집
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• 2015.05a
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• pp.60-60
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• 2015

Hybrid histidine kinase is a part of two-component system that is required for various stress responses and pathogenesis of pathogenic fungi. In the present study, Tco1, a homologue of human pathogen Cryptococcus neoformans Tco1 encoding a hybrid histidine kinase, was identified in corn smut pathogen Ustilago maydis by bioinformatic analysis. To explore the role of Tco1 in the virulence of U. maydis, mutants in which the tco1 gene was partially deleted were constructed by allelic exchange. The U. maydis tco1 mutants did show unaltered growth rate on axenic medium but were unable to produce conjugation tubes and develop fuzzy filaments, resulting in impaired mating of compatible strains. The expression levels of prf1, pra1, and mfa1 which are involved in the pheromone pathway significantly decreased in the tco1 mutants. In inoculation tests to host, the tco1 mutants showed significantly reduced ability in the production of anthocyanin pigments and tumor development on maize leaves. Overall, the combined results indicated that Tco1 plays important roles in sexual development and virulence of U. maydis by regulating the expression of the genes involved in the pheromone pathway.

• Atmosphere
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• v.29 no.5
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• pp.659-669
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• 2019

This study assesses the quality of the total column ozone (TCO) data from five reanalysis datasets against nine independent observation in East Asia. The assessed datasets are the ECMWF Interim reanalysis (ERAI), Monitoring Atmosphere Composition and Climate reanalysis (MACC), Copernicus Atmosphere Monitoring Service reanalysis (CAMS), the NASA Modern-Era Retrospective analysis for Research and Applications, Version2 (MERRA2), and NCEP Climate Forecast System Reanalysis (CFSR). All datasets reasonably well capture the spatial distribution, annual cycle and interannual variability of TCO in East Asia. In particular, characteristics of TCO according to the latitude difference were similar at all points with a maximum bias of less than about 4%. Among them, CAMS and CFSR show the smallest mean bias and root-mean square error across all nine ground-based observations. This result indicates that while TCO data in modern reanalyses are reasonably good, CAMS and CFSR TCO data are the best for analysing the spatio-temporal variability and change of TCO in East Asia.

• Journal of the Korean Society of Propulsion Engineers
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• v.8 no.3
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• pp.61-67
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• 2004

The extinction characteristics of the solid propellant were studied experimentally in this paper. These characteristics are required for designing TCO (thrust cut off) system of the solid rocket motor Parameters to characterize solid propellant extinction were defined by physical observation. A device was designed (or acquiring these parameters and the firing tests were implemented to get the preliminary data for the extinction characteristics of HTBP propellant.

• Solar Energy
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• v.8 no.1
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• pp.68-73
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• 1988

In the glass/TCO/p-i-n a-Si/Al type of amorphous silicon solar cell, the effects on solar cell efficiency and metastability for the various kinds of TCO analyzed by SAM and ESCA, which was used to measure the diffusion profiles of In and Sn and the Fermi energy shifts in the TCO/p interface respectively. Indium which diffused into a-Si p-layer did not have any significant effects on the Fermi level shift of p-layer when the content of $B_2H_6/SiH_4$ in p-layer was at 1 gas%. The cell fabricated on $SnO_2$ turned out to have the best cell photovoltaic characteristics. ITO fabricated by electron beam deposition system, which was shown to have the greatest rate of diffusion of Indium in ITO/p interface produced the worst metastability among the cells tested.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.5
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• pp.342-348
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• 2011

This study analyzes the current and after retrofit energy consumption of lighting and cooling system of a superstore in Seoul. Energy consumption data were measured and collected with a measurement system. Annual energy consumption was calculated using TRNSYS program. After replacing lighting and chiller with higher efficiencies, annual TOE consumption decreased from 1,066 before retrofit to 832 after retrofit, saving 234 TOE (22%) in total. Similarly, total annual $TCO_2$ consumption decreased from 2,214 to 1,721, reducing 493 $TCO_2$ (22%) during this pilot study.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.4
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• pp.89-95
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• 2005

Thrust cut off(TCO) system is installed at the port of a rocket motor case forward dome. The snap ring and the closure are escaped sequentially by pulling out a wedge under internal pressure. The hydraulic structural tests of TCO and numerical simulations were performed, and both results were compared to understand the deformation behavior of TCO. By increasing splines symmetrically, the sealing capacity of TCO can be improved significantly. The escape pressure of TCO increases according to the increase of friction coefficient and there is a critical friction coefficient beyond which the snap ring can not be nearly escaped even after forced escape of wedge. Under low friction coefficient the snap ring is contracted to radial direction and easily escaped. But, under high friction coefficient, the snap ring can not be escaped from the port even after severe plastic deformation.