• 대한의용생체공학회:의공학회지
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• 제34권4호
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• pp.218-225
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• 2013

In this paper hair bundle feature model and integration method for hair cell models were proposed. The proposed hair bundle feature model was based on spring-damper-mass model. Input of integrated vestibular hair cell model was frequency and output was interspike interval of hair cell that was reflected the feature of hair bundles. Irregular afferents that had a great gain variation showed reduction of negative stiffness section. Regular afferents that had a small gain variation, however, showed same feature with base negative stiffness feature. As a result, integrated vestibular hair cell model showed almost the same modeling data with experimental data in the modeled eleven frequency bands. It is verified that the proposed model is a good model for hair bundle feature modeling.

• 토지주택연구
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• 제11권4호
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• pp.105-113
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• 2020

In this research, the automated system for 3D modeling and stability evaluation of caisson was developed. It is possible to build a BIM model while examining the stability of the structures to improve the practical use of BIM technology. This study analyzed industry cases and guidelines for caisson stability evaluation and BIM-based modeling. As a result, the data for calculating the stability evaluation of caisson as well as the modeling parameters were derived. In particular, the automated system for 3D modeling, which reflects more than 30 parameters, allows for BIM models for various types of the caisson, such as open-cell caisson, open-cell caisson with uneven, slit caisson, slit caisson with uneven, and curved caisson. The study tested the proposed system using case studies and found that it helps not only to automate the BIM model with various caisson types as parameters but also to make partial shape changes accessible. The study also confirmed that the stability evaluation can be quickly carried out with shapes changed. Finally, the study results suggest that the proposed method should complete the task seven times as fast as the conventional work method.

• Journal of Mechanical Science and Technology
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• 제20권3호
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• pp.391-398
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• 2006

This work involves a method for modeling the flow distribution in the stack of a solid oxide fuel cell. Towards this end, a three dimensional modeling of the flow through a Solid Oxide Fuel Cell (SOFC) stack was carried out using the CFD analysis. This paper examines the efficacy of using cold flow analysis to describe the flow through a SOFC stack. It brings out the relative importance of temperature effect and the mass transfer effect on the SOFC manifold design. Another feature of this study is to utilize statistical tools to ascertain the extent of uniform flow through a stack. The results showed that the cold flow analysis of flow through SOFC might not lead to correct manifold designs. The results of the numerical calculations also indicated that the mass transfer across membrane was essential to correctly describe the cathode flow, while only temperature effects were sufficient to describe the anode flow in a SOFC.

• ETRI Journal
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• 제17권3호
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• pp.45-63
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• 1995

This paper proposes an algorithm to improve the correlation between giga-hertz transverse electromagnetic (GTEM) cell and open area test site (OATS). It is based on the dipole modeling process of an unknown source object in a GTEM cell and on the evaluation of the approximate far field equations correlated with measured GTEM powers at output port of the GTEM cell. In this algorithm, the relative phase differences between dipole moments play an important part in modeling the test object as a set of dipoles and offer stable calculation of emission values. The radiated emission test using this algorithm requires fifteen orientations of equipment under test, but the increased orientations as compared with the previous method have little effect on the time needed for testing. Radiation from a notebook computer has been tested for statistical analysis of the correlation between GTEM data and OATS data. The emission test results of the notebook computer show that the mean, the standard deviation, and the correlation coefficient are -0.62, 1.99, and +0.85, respectively. These figures indicate that this algorithm provides improved accuracy in the measurement of electromagnetic emissions over the previous method.

• 한국수소및신에너지학회논문집
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• 제22권4호
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• pp.481-487
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• 2011

A fuel cell vehicle using a polymer electrolyte membrane fuel cell (PEM FC) as power source produces electric power by consuming the fuel, hydrogen. The unconsumed hydrogen is recirculated and reused to gain higer stack efficiency and to maintain the humidity in the anode side of the stack. So it is needed considering fuel efficiency to recirculated hydrogen. In this study, the indirect hydrogen recirculation flow rate measurement method for fuel cell vehicle is presented. By modeling of a convergent nozzle ejector and a hydrogen recirculation blower for the hydrogen recirculation of a PEM FC, the hydrogen recirculation flow rate was calculated by means of the mass balance and heat balance at Anode In/Outlet.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1495-1497
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• 2004

This paper presents an effective modeling scheme of SPE cell system for hydrogen production. As oxygen and hydrogen produced by water electrolysis using SPE are high purity, we can use oxygen in biomedical and hydrogen could be used in many ways. Recently, it is under the eye as a surplus power storage system. PSCAD/EMTDC model of SPE cell system for hydrogen production to efficiently utilize Solar cell energy which produces effectively hydrogen energy is showed in this paper. The simulated results are then verified by comparing them with the actual values obtained from the data acquisition system. Authors are sure that it is a useful method to the researchers who study SPE cell system for hydrogen production.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.1096-1100
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• 2003

A fast Q-tensor method, which can model the defect dynamics in a liquid crystal director field is presented. The method is used to model the defect dynamics occurring during the "warm-up" of a ${\pi}-cell$ device.

• Journal of Electrical Engineering and Technology
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• 제2권2호
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• pp.231-240
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• 2007

This paper presents an advanced modeling and simulation technique applied to DC/DC power electronic converters fed through renewable energy power sources. The distributed generation (DG) system at the Illinois Institute of Technology, which employs a phase-l system consisting of a photovoltaic-based power system and a phase-2 system consisting of a fuel cell based primary power source, is studied. The modeling and simulation of the DG system is done using the generalized state space averaging (GSSA) method. Furthermore, the paper compares the results achieved upon simulation of the specific GSSA models with those of popular computer aided design software simulations performed on the same system. Finally, the GSSA and CAD software simulation results are accompanied with test results achieved via experimentation on both, the PV-based phase-l system and the fuel cell based phase-2 power system.

• 비파괴검사학회지
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• 제25권3호
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• pp.157-162
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• 2005

In order to evaluate the corrosion of reinforcing steel-bars (rebar) in concrete, a nondestructive evaluation by the half-cell potential method is currently applied. In this study, potentials measured on a concrete surface are compensated into those on the concrete-rebar interface by the inverse boundary element method (IBEM). Because these potentials are obtained three-dimensionally (3-D), 3-D visualization is desirable. To this end, a visualization system has been developed by using VRML (Virtual Reality Modeling Language). As an application, results of a reinforced concrete (RC) slab with corroded rebars are visualized and discussed.

• Journal of Electrical Engineering and Technology
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• 제13권3호
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• pp.1147-1155
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• 2018

This paper presents an improved method to determine the internal parameters for improving accuracy of a lithium ion battery equivalent circuit model. Conventional methods for the parameter estimation directly using the curve fitting results generate the phenomenon to be incorrect due to the influence of the internal capacitive impedance. To solve this phenomenon, simple correction procedure with transient state analysis is proposed and added to the parameter estimation method. Furthermore, conventional dynamic equation for correction is enhanced with advanced RC impedance dynamic equation so that the proposed modeling results describe the battery dynamic characteristics more exactly. The improved accuracy of the battery model by the proposed modeling method is verified by single cell experiments compared to the other type of models.