• Journal of the Korean Society of Safety
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• v.31 no.4
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• pp.143-149
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• 2016

In this study, a series of numerical simulation of dam break flow was conducted using EFDC model, and input conditions including cell size, time step, and turbulent eddy viscosity were considered to analyze parameter sensitivity. In case of coarse mesh layout, the propagated length of the shock wave front was ${\Delta}_x$ longer than that of other mesh layouts, and the velocity results showed jagged edge, which can be cured by applying fine grid mesh. Turbulent eddy viscosity influenced magnitude of the maximum velocity passing through gate up to 20% and the cell Peclet number less than 2.0 ensured no numerical oscillations.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.91-91
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• 2001

This paper is on 3D virtual reality simulator for terminal in connection with terminal operation system in real terminal in order to reflex complicated terminal operation and environment. This simulator has been developed based on knowledge of terminal planning and operation analysis and advanced software technologies that TSB has accumulated over 10 years. In this study, the simulator generates terminal layout and component of terminal in the same environments as the real terminal in Ohi, Japan and uses real operation system using real planning data in the past in order to describe 3D VR simulation that integrates container handling equipment and real time communication of job ordering. In addition, it is suggested various statistics and analysis report can be used to derive decision supporting factors that optimize design of terminal and improve operation, which will eventually increase terminal productivity.

• Journal of the Korean housing association
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• v.13 no.4
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• pp.53-60
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• 2002

The purpose of this study is to provide the guidelines for the planning and design of officetels, meeting the requirements of life in one-person household which is a new type in housing market. Literature survey is used as a research method. We analyzed the needs of officetel residents, by reviewing researches and by examining internet homepages and catalogs of 20 officetels sold since 2000. Case study analysis method is used as a qualitative analysis. The major findings of this study are as follows; 1) In dwelling unit space, it lacks the independence of working space and the privacy of living space. Therefore, the provision of various unit plans, such as 2-bay plan, unit with mezzanine floor or movable walls, layout of kitchen and dining area in window side, is proposed. 2) In communal space, it lacks the consideration of natural environments and the systematic maintenance. Therefore, the introduction of communal workshop and conference rooms and of various types of garden space, is proposed.

• Structural Monitoring and Maintenance
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• v.3 no.2
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• pp.145-155
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• 2016

The Pulse-Pre Pump Brillouin Optical Time Domain Analysis (PPP-BOTDA) technique is introduced to implement the multi-direction strain measurement. The monitoring principle is stated. The layout scheme of optical fibers is proposed. The temperature compensation formula and its realizing method are given. The experiments, under tensile load, combined bending and tensile load, are implemented to validate the feasibility of the proposed method. It is shown that the PPP-BOTDA technique can be used to discriminate the multi-direction strains with high spatial resolution and precision.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1481-1498
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• 2007

As railroad industry face the new Renaissance era, effective and efficient maintenance methods for rolling stock operation are required with advanced railroad technology. All kinds of railroad systems such as high speed long distance train, metropolitan mass transit and light rail require systematic maintenance technology in order to maintain the safe railroad operation. Simulation models for detailed operations of the sample maintenance center are developed. In this study, standard maintenance procedures, layout, equipments and number of workers of Siheung Metropolitan Railroad Maintenance Rolling Stock Depot are considered. The proposed simulation models are developed using simulation package ARENA. Three simulation analysis using the developed simulation model are done. First, the bottleneck operation is identified. Second, the relationship between maintenance center size, number of workers and cycle time is analyzed. Lastly, the scheduling performances between PERT/CPM and Critical Chain Project Management(CCPM) are compared.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.251-252
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• 2015

The designed hybrid generation system (HGS) not only consider the voltage condition of grid connection point but also do reactive power support according to the transmission system operator's directions. The PCS operation plan in HGS should be supported by precise transferred quantity expectation about reactive power because the system has large physical areas and also be interconnected with grid through long transmission system. Therefore, the realistic measuring process about transferred reactive power quantity by utilizing HGS is required to consider additional compensation plan. In this paper, an reactive power transferred capability of HGS with expected parameter is analyzed, and imposed to the simulation process that is performed on EMTDC environment. Basically, grid information and system characteristics were utilized with Jeju island in Korea, and the performance analysis is carried out based on the composed layout in ongoing project.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.592-595
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• 2011

A numerical investigation on a suction vortices, free vortices and subsurface vortices behavior in the model sump system with multi-intakes is performed A test model sump and piping system were designed based on Froude similitude for the prototype of the recommended structure layout by HI-9.B Standard for Pump Intake Design of the Hydraulic Institute. A numerical analysis of three dimensional multiphase flows through the model sump is performed by using the finite volume method of the CFX code with multi-block structured grid systems. A ${\kappa}-{\omega]$ ShearStressTransportturbulencemodelandthe Rayleigh-Plesset cavitation model are used for solving turbulence cavitating flow. From the numerical analysis, several types of vortices are reproduced and their formation, growing shedding and detailed vortex structures are investigated. To reduce abnormal vortices, an anti-vortex device is considered and its effect is investigated and discussed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.3 s.246
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• pp.302-309
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• 2006

Effective mixing plays a crucial role in microfluidics for biochemical applications. Owing to the small device scale and its entailing the low Reynolds number, the mixing in microchannels proceeds very slowly. In this work, we optimize the configuration of obstacles in the Y-channel mixer in order to attain maximum mixing efficiency. Before the optimum design, mixing characteristics are investigated using unstructured grid CFD method. Then, the analysis method is employed to construct the approximate analysis model to be used in the optimization procedure. The main optimization tool in the present work is sequential quadratic programming method. Using this approximate optimization procedure, we may obtain the optimum layout of obstacles in the Y-channel mixer in an efficient manner, which gives the maximum mixing efficiency.

• Journal of Korean Society for Quality Management
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• v.19 no.1
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• pp.163-169
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• 1991

This paper studies computer programming for Two-Way Layout with Multiple Observations - Fixed Model using the subroutines of the former paper. The following items are considered in the PC computer programming: * significant digits in the computation of Sum of Squares * containing the necessary F-distribution values in the program * including the necessary estimation after the Analysis of Variance * following the rules of KS A 0021 in rounding off digits etc. The running results of Analysis of Variation Table and Estimations of a fictitious example is added with the parts of PC program. It should be mentioned that the main purpose of this paper is in the arousing of the discussion about significant digits concept in the PC computer programming for various kinds of Statistical Methods.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.1
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• pp.94-102
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• 2012

The aim of this paper is to research the change in the turbulent flow and the AOA occurred by $60^{\circ}$ crosswind to the direction of runway through the three-dimensional numerical analysis and to predict the take-off and landing flight stability. As a result, the maximum amplitude of AOA variation on runway reached $4.88^{\circ}$ within 7 second because of the wake formed by the constructions in the vicinity of the airport, and the overall effects appeared as an irregular aperiodic forms. Additionally, it was observed that the layout and shape of the buildings effected on the strength of turbulence directly, and the rapid flow generated between the buildings changed into stronger wake and eventually expected that the flow raises serious take-off and landing flight instability.