• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.174-180
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• 2010

Conductive and radiative thermal model configurations of an imager of a geostationary satellite are presented. A two-plane method is introduced for three dimensional conductive coupling which is not able to be treated by thin shell plate thermal modeling technique. Especially the two-plane method is applied to massive matters and PIP(Payload Interface Plate) in the imager model. Some massive matters in the thermal model are modified by adequate correction factors or equivalent thickness in order to obtain the numerical results of thermal modeling to be consistent with the analytic model. More detailed nodal breakdown is specially employed to the object which has the rapid temperature gradient expected by a rule of thumb. This detailed thermal model of the imager is supposed to be used for detailed analyses and test predictions, and be correlated with the thermal vacuum test results before final in-flight predictions.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.16 no.4
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• pp.225-234
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• 2012

We present two high-order potential flow models for the evolution of the interface in the Rayleigh-Taylor instability in two dimensions. One is the source-flow model and the other is the Layzer-type model which is based on an analytic potential. The late-time asymptotic solution of the source-flow model for arbitrary density jump is obtained. The asymptotic bubble curvature is found to be independent to the density jump of the fluids. We also give the time-evolution solutions of the two models by integrating equations numerically. We show that the two high-order models give more accurate solutions for the bubble evolution than their low-order models, but the solution of the source-flow model agrees much better with the numerical solution than the Layzer model.

• Journal of Korea Foundry Society
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• v.20 no.2
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• pp.129-140
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• 2000

This study aims at the phase-field modeling of the phase transformation in graphitization of the cast iron. As the first step, we constructed a phase-field model including the phases with negligible solubility. Under the dilute regular solution approximation, a simplified version of the phase-field model was obtained, which can be used for the phase transformation related with the stoichiometric phases. The results from the numerical calculation of the phase-field model was in good agreement with the exact analytic solution. The compositional shift due to Gibbs-Thomson effect can be reproduced within 0.5% error in the numerical calculation. The interface velocity, whereas, in numerical calculation of phase-field model appeared to be 15% larger than that from the analytic solution. This error is due to the shift of the interface position in phase-field model from the position with ${\phi}=0.5$.

• Journal of the Ergonomics Society of Korea
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• v.30 no.1
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• pp.179-186
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• 2011

Objective: This study is to review three representative psychological perspectives that explain scientific construct of emotion, that are the discrete emotion model, appraisal model, and dimensional model. Background: To develop emotion sensitive interface is the fusion area of emotion and scientific technology, it is necessary to have a balanced mixture of both the scientific theory of emotion and practical engineering technology. Extensional theories of the emotional structure can provide engineers with relevant knowledge in functional application of the systems. Method: To achieve this purpose, firstly, literature review on the basic emotion model and the circuit model of discrete emotion model as well as representative theories was done. Secondly, review on the classical and modern theories of the appraisal model emphasizing cognitive appraisal in emotion provoking events was conducted. Lastly, a review on dimensional theories describing emotion by dimensions and representative theories was conducted. Results: The paper compared the three models based on the prime points of the each model. In addition, this paper also made a comment on a need for a comprehensive model an alternative to each model, which is componential model by Scherer(2001) describing numerous emotional aspects. Conclusion: However, this review suggests a need for an evolved comprehensive model taking consideration of social context effect and discrete neural circuit while pinpointing the limitation of componential model. Application: Insight obtained by extensive scientific research in human emotion can be valuable in development of emotion sensitive interface and emotion recognition technology.

• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.128-131
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• 2000

In this paper, the animated simulation system (Anisim) is proposed in order to develope an efficient functional system verification tool. It displays the simulation results of the designed system using graphic animation with various models lot the target system. With simple interface definitions given by the user, Anisim generates interface codes automatically. Users can describe and model the target system with the generated interface codes. Since the simulation engine is implemented in C-language, modeling is very simple and simulation can be performed in real time.

• Proceedings of the ESK Conference
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• 1996.04a
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• pp.253-258
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• 1996

Virtual reality environment system is expected to be used as a new user interface tool oweing to its high immersiveness and high interactivity. To use VR interface effectively, we should identify the characteristics of the three-dimensional control tasks as if we did in two-dimensional graphic user interface environments. As a first step, we validated Fitts'law for the three-dimensional pointing tasks with the two input devices, Spaceball and Spacemouse. Different from the two-dimensional control tasks, VR pointing tasks needed inclusion of a new variable, size of the moving object, to Fitts'law. The modified

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.3
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• pp.61-66
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• 1993

The interface properties of Fluoride/GaAs structures were investigated. It was foung that rapid thermal annealing(RTA) typically 800-850$^{\circ}C$for 1 min, was useful for improving the interface properties of that structures. The analysis by means of SIMS indicated that interdiffusion of each constitutional atom through the interface was negligible. The interfacial atom bonding model for RTA treatment was proposed. Bases on these results, inversion-type GaAs MISFET was fabricated using standard planar technologies.

• Journal of the Korean Society of Safety
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• v.10 no.3
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• pp.21-29
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• 1995

The automotive transmission is the principal component of the power transmission system which converts the engine power into the adjustable power for the vehicle driving system. To the unskilled driver the automization of transmission is required for the safety and fuel economy. In this study, the dynamic model of the automotive power transmission system was presented and simulation program and interface board which interface IBM-PC with ECU was devloped. Through the traveling simulation by interfacing ECU with simulation program, the shifting transients are investigated. For verification of simulation experiment was carried out, the results of simulation was agreed well with those of simulation.

• Structural Engineering and Mechanics
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• v.62 no.1
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• pp.43-54
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• 2017

In this study, the failure behavior of composite material in the biaxial and off-axis loading is studied based on a computational micromechanical model. The model is developed so that the combination of mechanical and thermal loading conditions can be considered in the analysis. The modified generalized plane strain assumption of the theory of elasticity is used for formulation of the micromechanical modeling of the problem. A truly meshless method is employed to solve the governing equation and predict the distribution of micro-stresses in the selected RVE of composite. The fiber matrix interface is assumed to be perfect until the interface failure occurs. The biaxial and off-axis loading of the SiC/Ti and Kevlar/Epoxy composite is studied. The failure envelopes of SiC/Ti and Kevlar/Epoxy composite in off-axis loading, biaxial transverse-transverse and axial-transverse loading are predicted based on the micromechanical approach. Various failure criteria are considered for fiber, matrix and fiber-matrix interface. Comparison of results with the available results in the litreture shows excellent agreement with experimental studies.

• Advances in aircraft and spacecraft science
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• v.4 no.6
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• pp.639-650
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• 2017

The objective of this paper is to obtain three-dimensional (3D) effective properties for layered composites with imperfect interfaces using mechanics of structure genome. The imperfect interface is modeled using linear traction-displacement model that allows small infinitesimal displacement jump across the interface. The predictions obtained from the current analysis are compared with the 3D finite element analysis (FEA). In this study, it is found that the present model shows excellent agreement with the results obtained using 3D FEA by employing periodic boundary conditions. The prediction also reveals that in-plane longitudinal and shear moduli, and all Poisson's ratios are observed to be not affected by the interfacial stiffness while the predictions of transverse longitudinal and shear moduli are significantly influenced by interfacial stiffness.