• Proceedings of the Membrane Society of Korea Conference
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• 2005.05a
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• pp.131-135
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• 2005

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.50-51
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• 2018

Although the introduction of new materials and new construction methods and overseas materials has become more active due to the diversification of the construction market, the quality standards of waterproofing methods in Korea are insufficient. In particular, the quality control standard is applied to the KS F 2622:08 (Membrane Waterproofing layer performance test method), which is the existing standard, to prepare standards for quality control of waterproof materials, which is increased in Korea.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.113-116
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• 2004

Water demand and wastewater production is steeply increasing and the gap between water supply and demand is getting wider. Wastewater is considered a major water resource in many countries. Therefore, wastewater reuse has been considered as a promising solution to the shortage of water resources (Madwar and Tarazi, 2002; Fane, 1996; Bodalo-Santoyo et al., 2003; Mohsen and Jaber, 2002; Nicolaisen, 2002; Lawrence2002).(omitted)

• Proceedings of the Membrane Society of Korea Conference
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• 2005.11a
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• pp.105-109
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• 2005

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.2
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• pp.118-123
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• 2008

For the hydrogen recirculation system of the PEMFC (polymer electrolyte membrane fuel cell), the ejector is useful to improve the efficiency of the fuel cell system. However, conventional ejector does not keep its entrainment ratio good when the various power duties is required by the fuel cell system. In this study, the variable multi-ejector acceptable in the whole duty range required from the fuel cell hybrid mini-bus is developed. Consequently, the performance of the developed ejector is verified by the experiments based on the real operating conditions.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2255-2260
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• 2007

This Paper focuses on modeling and simulation to analyze the characteristic of hybrid vehicle. The system includes proton exchange membrane fuel cell(PEMFC), photovoltaic generator(PV), lead-acid battery, motor, vehicle and controller. Main electricity is produced by the PEMFC and battery to meet the requirements of a user load. When vehicle is parked in a sunny place, extra power is generated by the photovotaics and is charged in a battery for next drive. Further we evaluate usefulness of this hybrid vehicle by using ADVISOR - the advanced vehicle simulator written in the Matlab/Simulink environment. According to simulation results, the extra power obtained by photovoltaics which have been explored in nature conditions can help to reduce the electrical load of PEMFC and increase the efficiency (over 30%).

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.459-461
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• 2002

A new class of materials based on organic and inorganic species combined at a molecule level has obtained more attention recently[1]. HPA(heteropolyacid) shows unmatched applied perspective in terms of synthesis chemistry, analysis chemistry, biology, medicine and materials science[2]. As a potential photochemical material, the hybrid system of HPA and polymer has been investigated. However, the design and synthesis of heteropolyacid-based hybrids, which are at the forefront of the materials chemistry research, is still in its infancy. (omitted)

• International Journal of Automotive Technology
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• v.6 no.4
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• pp.429-436
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• 2005

In this paper, operation algorithms are evaluated for a fuel cell hybrid electric vehicle (FCHEV). Power assist, load leveling and equivalent fuel algorithm are proposed and implemented in the FCHEV performance simulator. It is found from the simulation results that the load leveling algorithm shows poor fuel economy due to the system charge and discharge efficiency. In the power assist and equivalent fuel algorithm, the fuel cell stack is operated in a relatively better efficiency region owing to the battery power assist, which provides the improved fuel economy.

• International Journal of Automotive Technology
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• v.5 no.4
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• pp.287-295
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• 2004

A performance simulator for the fuel cell hybrid electric vehicle (FCHEV) is developed to evaluate the potentials of hybridization for fuel cell electric vehicle. Dynamic models of FCHEV's electric powertrain components such as fuel cell stack, battery, traction motor, DC/DC converter, etc. are obtained by modular approach using MATLAB SIMULINK. In addition, a thermodynamic model of the fuel cell is introduced using bondgraph to investigate the temperature effect on the vehicle performance. It is found from the simulation results that the hybridization of fuel cell electric vehicle (FCEV) provides better hydrogen fuel economy especially in the city driving owing to the braking energy recuperation and relatively high efficiency operation of the fuel cell. It is also found from the thermodynamic simulation of the FCEV that the fuel economy and acceleration performance are affected by the temperature due to the relatively low efficiency and reduced output power of the fuel cell stack at low temperature.

• Structural Engineering and Mechanics
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• v.29 no.6
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• pp.643-658
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• 2008

In this paper, we present a quadratic element model based on non-conforming displacement modes and modified shape functions. This new and refined 8-node hybrid stress plane element consists of two additional non-conforming modes that are added to the translational degree of freedom to improve the behavior of a membrane component. Further, the modification of the shape functions through quadratic polynomials in x-y coordinates enables retaining reasonable accuracy even when the element becomes considerably distorted. To establish its accuracy and efficiency, the element is compared with existing elements and - over a wide range of mesh distortions - it is demonstrated to be exceptionally accurate in predicting displacements and stresses.