• Journal of computational fluids engineering
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• v.8 no.2
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• pp.42-48
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• 2003

The issues associated with the application of CFD for ship design are addressed. Doubtlessly at the moment, CFD tools are very useful in evaluating hull forms prior to traditional towing tank tests. However, time-consuming pre-processing is an obstacle in the daily application of CFD tools to improve hull forms. The accuracy of computational modeling without sacrificing the usability of CFD system is also to be assessed. The wave generation is still predicted by using potential panel methods, while velocity profiles entering into propeller plane is solved using turbulent flow solvers. The choice of turbulence model is a key to predict nominal wake distribution within acceptable accuracy. The experimental data for CFD validation are invaluable to improve physical and numerical modeling. Other applications of CFD for ship design than hull form improvement are also given. It is certain that CFD can be a cost-effective tool for the design of new and better ships.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.5-8
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• 2002

The issues associated with the application of CFD for ship design are addressed. It is quite certain that the CFD tools are very useful in evaluating hull forms a prior to traditional towing tank tests. However, the time-consuming pre-processing is an obstacle in the daily application of CFD tools to improve hull forms. The accuracy of computational modeling without sacrificing the usability of CFD system is also to be assessed. The wave generation is still predicted by using potential panel methods, while velocity profiles entering into propeller plane is solved using turbulent flow solvers. The choice of turbulence model is a key to predict nominal wake distribution within acceptable accuracy. The experimental data for CFD validation are invaluable to improve physical and numerical modeling. Other applications of CFD for ship design than hull form improvement are also given. It is certain that CFD can be a cost-effective tool for the design of new and better ships.

• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.283-286
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• 2012

The analytical model determining the unknown parameters of reaction rate equation which is necessary to simulate the combustion phenomena of energetic materials is proposed. The relationship between detonation velocity and size effect of energetic materials is derived from simplified JWL++ model. Theoretical model is used to investigate the combustion characteristics of certain energetic materials before running Hydrocode by pre-determination of unknown parameter, b. When b=0.8, the behavior of HANFO gunpowder is in the form of concave-up and ANFO explosives has the concave-down form in case of b=1.5. The analytical model provides efficient and highly accurate results rather than previous method which simulated the unconfined-rate-stick via the numerical means.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.359-362
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• 2000

In this paper, we propose a test pattern generation algorithm on the basis of the identification of undetectable faults for Speed-Independent(SI) asynchronous control circuits. The proposed methodology generates tests from the specification of a target circuit, which describes the behavior of the circuit in the form of Signal Transition Graph (STG). The proposed identification method uses only topological information of a target circuit and reachability information of a fault-free circuit, which is generated in the form of Binary Decision Diagram(BDD) during pre-processing. Experimental results show that high fault coverage over single input stuck-at fault model is obtained for several synthesized SI circuits and the use of the identification process as a preprocessing decreases execution time of the proposed test generation with negligible costs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.1
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• pp.9-14
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• 1990

In this paper, I derived a two-dimensional analytical closed-form expression of the threshold voltage for small size MOSFET. The invalid assumptions of constant surface portential or uniform depletion depth were corrected. A comparison between the results of pre-models analyses and the present's proved that this paper's model is quite accurate. Therefore, this model will become a useful design tool for short channel MOSFET.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.135-138
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• 2003

In this paper, we provide a reliable few controller design method for descriptor systems satisfying asymptotic stability with $H_\infty$ norm bound and all actuator failures occurred within the pre-specified subset. The proper condition for the existence of a reliable $H_\infty$ controller and the controller design method are proposed by linear matrix inequality(LMI), Schur complements, and singular value decomposition. All solutions can be obtained simultaneously because the presented sufficient condition can be expressed as an LMI form.

• East Asian Economic Review
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• v.20 no.2
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• pp.169-190
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• 2016

This paper tests the weak-form efficient market hypothesis for Korean industry-sorted portfolios. Based on a panel variance ratio approach, we find significant mean reversion of stock returns over long horizons in the pre Asian currency crisis period but little evidence in the post-crisis period. Our empirical findings are consistent with the fact that Korea accelerated its integration with international financial market by implementing extensive capital liberalization since the crisis.

• IE interfaces
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• v.12 no.4
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• pp.506-513
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• 1999

We use a path analysis to identify influential latent variables on employees' anticipated commitment to a merged bank. Survey samples are taken from Hanvit bank which is a merged form of Hanil and Sangup. Latent variables used in the path analysis are perceptions of organizational support, contact conditions, organizational unity, employee threat and organizational commitment. We find an interesting pre-merger group membership effect as well as merger pattern perceived by employees on the path for the anticipated commitment to the merged bank.

• Journal of Periodontal and Implant Science
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• v.20 no.1
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• pp.147.2-147.2
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• 1990

• Journal of the Korean housing association
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• v.11 no.2
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• pp.97-106
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• 2000

In this study, we analyze space alternation, which is shown pre-development and post-development in the reconstruction apartment. We point out problems in terms of the city and dwelling environment, and in looking for drawing up a plan for improvement as well. As a result of our research, we offer some important observations and conclusions. Ourdoor space of the site after the reconstruction caused inconvenience to the residents due to the plan for high-storeys, high-density, And the building shape and arrangement provide changeable conditions form line figures to variable figures due to courtyard patterns. The courtyard space changes into a parking area ; therefore the outdoor site gives worse circumstances.