• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.109-112
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• 2003

Web documents specified with HTML and CSS is displayed with high quality on the web browser. However, basically, any printed pages don't have the same quality of softcopy. The reason is HTML and CSS is not suit for printing. The XSL-FO(XSL-Formatting Object) is Formatting Language for imaging of web document and The PostScript is one of the most famous PDL(Page Description Language). To get high-quality pages, we propose the design of converter which translate XML-FO into PostScript format. Using the designed converter, we can get hardcopies with high quality.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.527-539
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• 2018

The subway used by many passengers is required to maintain a safe and comfortable environment and PSD (Platform Screen Door) must be installed in the platform after reinforcing the standard in 2003. In the previous research, in case of subway fire to control it, it is necessary to design the optimal ventilation and smoke exhaust system according to equipment capacity of the smoke exhaust system. Therefore, in this study, based on the results of previous research, three-dimensional numerical analysis was performed for the CO gas and smoke flow by the subway ventilation system in case of platform fire. As a result of this study, it was found that in case of emergency, if only the upper-level smoke exhaust system is activated, the risk of evacuation is high due to CO gas (653.8 ppm) and smoke concentration ($768.4mg/m^3$). And when all the smoke exhaust systems are activated and only the fire side PSD is opened, CO gas (36.0 ppm) and smoke concentration ($26.2mg/m^3$) are detected and the propagation range of smoke flow was reduced. When all the smoke exhaust systems are activated and only the fire side PSD is closed, it was analyzed as the most effective ventilation mode in the evacuation environment due to the absence of smoke-recirculation.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.2
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• pp.59-64
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• 2022

Effects of film stack structure and peeling rate on the peel strength of screen-printed (SP) Ag/polyimide (PI) systems were investigated by a 90° peel test. When PI film was peeled at PI/SP-Ag and PI/SP-Ag/electroplated (EP) Cu structures, the peel strength was nearly constant regardless of the peeling rate. When EP Cu was peeled at EP Cu/SP-Ag/PI structure, the peel strength continuously increased as peeling rate increased. Considering uniaxial tensile test results of EP Cu/SP-Ag film with respect to loading rate, the increase of 90° plastic bending energy and peel strength was attributed to increased flow stress and toughness. On the other hand, viscoelastic PI film showed little variation of flow stress and toughness with respect to loading rate, which was assumed to result in nearly constant 90° plastic bending energy and peel strength.

• Journal of the Microelectronics and Packaging Society
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• v.17 no.1
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• pp.47-53
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• 2010

In this study, analyses on the stencil printing using solder paste were carried out. The key design parameters in the stencil printing process are printing conditions, stencil design, and solder paste properties. Among these parameters, the effects of physical properties of solder paste such as viscosity, surface tension, and contact angle on the stencil printing process were investigated. The analyses were performed for simple geometry and boundary conditions. In the analysis, solder paste was pushed into a stencil hole by pressure instead of printer pad. Considering the geometry and computational efficiency, axisymmetric analyses were adopted. A commercial software (COMSOL), which is well known in the area of micro-fluids analysis, was used. From the results, it was shown that viscosity of solder paste had an effect on the filling speed, while surface tension and contact angle had an effect on the filling shape.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.666-671
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• 2014

Using positive temperature coefficient (PTC) heater as supplementary heating for diesel engine vehicles with low heat source is a good method to enhance the heating performance during cold start. In this study, the PTC elements were made by using screen printing process for forming ohmic contact layer, and prototype of PTC heater was designed and made for a diesel engine vehicle. In process of designing the PTC heater, the thermal flow analysis of PTC element modules was conducted for verifying the effect of the shapes of contact surface between each of the components (cooling fin, insulator, ceramic element). We also investigated the performance characteristic (heating capacity, energy efficiency, pressure drop) of the PTC heater through the experiments. Therefore, the experimental results indicated that prototype of PTC heater had satisfactory performance. This study will be basis for improving the manufacturing process and increasing the performance of the PTC element and heater.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.2
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• pp.223-232
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• 2018

Bird screen meshes are installed at the air inlet and outlet ducts of spent fuel storage casks to inhibit the intrusion of debris from the external environment. The presence of these screens introduces an additional resistance to air flow through the ducts. In this study, a porous media model was developed to simplify the bird screen meshes. CFD analyses were used to derive and verify the flow resistance factors for the porous media model. Thermal analyses were carried out for concrete storage cask using the porous media model. Thermal tests were performed for concrete casks with bird screen meshes. The measured temperatures were compared with the analysis results for the porous model. The analysis results agreed well with the test results. The analysis temperatures were slightly higher than the test temperatures. Therefore, the reliability and conservatism of the analysis results for the porous model have been verified.

• Resources Recycling
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• v.12 no.1
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• pp.55-64
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• 2003

Presently, the reuse of waste FCC catalysts, which generated from the refining process of crack oil, after the removal of con-taminated metallic impurities have not been attempted domestically yet because the separation technology f3r the impurities from waste catalysts has not been established. As a basic study far the reusable portion from the waste FCC catalysts and treatment of metallic impurities are assured, there will be invoked an significant contribution not only in the recycling of abandoned wastes up to date but also in the treatment efficiency of wastes and extraction of economical benefits from them. The magnetic separation of impurities such as Fe, Ni, and V, from waste FCC catalyst has been attempted with or without its pre-oxidation at high temperature for the purpose of its reuse. The results showed that the separability of impurities by magnetic force was high far non-preoxidized catalysts compared with preoxidized ones, and employment of screen-type matrix showed a higher separation efficiency than ball-type matrix. The separability increased with the strength of magnetic field, and the method of ball matrix has separation efficiency of maximum 51.10%. The amount of metallic impurities was in the decreasing order of V, Ni, and Fe depending upon ICP analysis.

• The Journal of Engineering Geology
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• v.28 no.1
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• pp.69-79
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• 2018

The Korean government attempts to reduce $CO_2$ emissions by 37% to 314.7 Mt $CO_2$, down from the estimated 850.6 Mt $CO_2$ until 2030 in order to confront green house effect. In this context, in 2014, Korean government launched $CO_2$ Storage Environmental Management Research (K-COSEM) Center for carrying out pilot-scale research on $CO_2$ leakage from underground $CO_2$ storage facilities. For the detection of $CO_2$ leakage, it is necessary to identify hydrologeological and geophysical characteristics of the subject area. In the study site of Naesan-ri, Daeso-myeon, Eumseong-gun, Chungbuk Province, two times injection tests (June 28-July 24, 2017 and August 07-September 11, 2017) of $CO_2$ and $SF_6$ dissolved waters, respectively, was conducted to understand the leakage behavior of $CO_2$ from underground. The injection well was drilled to a depth of 24 m with a 21-m casing and screen interval of 21~24 m depth. Two times resistivity surveys on August 18, 2017 and September 1, 2017, were conducted for revealing the flow of the injected water as well as the electrical properties of the study site. The study results have shown that the high-resistivity zone and the low-resistivity zone are clearly contrasted with each other and the flow direction of the injected water is similar to natural groundwater flow. Besides, the low resistivity zone is widely formed from the depth of injection to the shallow topsoil, indicating that the weathered zone of high permeability has high $CO_2$ leakage potential.

• Korean Journal of Agricultural Science
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• v.36 no.1
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• pp.73-85
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• 2009

An investigation was conducted to get the basic data for establishing structural safety and environmental management of tomato greenhouses in Chungnam region. The contents of the investigation consisted of actual state of greenhouse structures and environmental control facilities. Most of greenhouses were arch type single-span plastic houses and they had too low height for growing tomatoes. Frameworks of multi-span greenhouses were suitable, but those of single-span were mostly insufficient. Every greenhouse had thermal curtain movable or covering fixed inside the greenhouse for energy saving, and heating facilities were mostly warm air heater. Irrigation facilities were mostly drip tube and controlled by manual operation or timer. Almost all of the greenhouses didn't install high level of environmental control facilities such as ventilator, air circulation fan, $CO_2$ fertilizer, insect screen, supplemental light, and cooling device.

• Journal of the Korean Institute of Gas
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• v.8 no.2 s.23
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• pp.15-27
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• 2004

The purpose of this paper is to improve the performance of Polymer electrolyte fuel cell(PEMFC) by studying the channel dimension of bipolar plates using commercial CFD program 'Fluent'. Simulations are done ranging from 0.5 to 3.0mm for different size in order to find the channel size which shoves the highst hydrogen consumption. The results showed that the smaller channel width, land width, channel depth, the higher hydrogen consumption in anode. When channel width is increased, the pressure drop in channel is decreased because total channel length Is decreased, and when land width is increased, the net hydrogen consumption is decreased because hydrogen is diffused under the land width. It is also found that the influence of hydrogen consumption is larger at different channel width than it at different land width. The change of hydrogen consumption with different channel depth isn't as large as it with different channel width, but channel depth has to be small as can as it does because it has influence on the volume of bipolar plates. however the hydrogen utilization among the channel sizes more than 1.0mm which can be machined in reality is the most at channel width 1.0, land width 1.0, channel depth 0.5mm and considered as optimum channel size. The fuel cell combined with 2cm${\times}$2cm diagonal or serpentine type flow field and MEA(Membrane Electrode Assembly) is tested using 100W PEMFC test station to confirm that the channel size studied in simulation. The results showed that diagonal and serpentine flow field have similarly high OCV and current density of diagonal (low field is higher($2-40mA/m^2$) than that of serpentine flow field under 0.6 voltage, but the current density of serpentine type has higher performance($5-10mA/m^2$) than that of diagonal flow field under 0.7-0.8 voltage.