• 한국전산유체공학회:학술대회논문집
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• 2000.05a
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• pp.91-98
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• 2000

The three-dimensional unsteady compressible Full Navier-Stokes equation solver with sliding multi-block method has been applied to analyze three dimensional characteristics of the flow field and compression wave around the high speed train which Is entering into a tunnel. The numerical scheme of AF + ADI was used to efficiently solve Navier-Stokes equations in the curvilinear coordinate system. The vortex formation around the nose region was found and the generation of compression wave due to the blockage effects was observed ahead of the train in the form of plane wave. The three dimensional characteristics of the flow field compared to the analytic results were discussed in detail. The variation of pressure of tunnel wall surface and velocity profile of the train are identified as the train enters into a tunnel. The changes in aerodynamic forces and streamlines of each specific sections are also discussed and presented.

• Journal of the Korean Society of Combustion
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• v.7 no.1
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• pp.52-57
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• 2002

A numerical investigation using a commercial CFD program of the Inter-Phase Slip Algorithm has been carried out for detail characteristics of particle motions and bubble behaviors in a two dimensional fluidized bed. The bed simulated has been operated with three different distributor geometries, such as bubble cap, nozzle, and perforated plate types. Experiments using a slit-type two-dimensional fluidized bed and a cylinder-type fluidized bed have been performed in order to confirm the simulation model. In addition, the numerical results are compared with the wellknown correlation of bubble sizes and bubble rising velocities by Mori and Wen [1]. The simulation model that we applied is shown to be useful to understand the relation between bubble behaviors and distributor geometries.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.7
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• pp.1-9
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• 2022

Peeling and dimensional deformation that occur during a manufacturing process are accompanied by an increase in the manufacturing cost and production time caused by manufacturing defects. In order to solve this problem, it is essential to predict risk factors at the design stage through computational analysis of the additive manufacturing process and to control shape distortion due to residual stress. In this study, the dimensional characteristics were improved by applying the distortion compensation design through computational analysis to minimize the distortion occurring in the DMLS(Direct Metal Laser Sintering) method of the metal additive manufacturing process.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.9
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• pp.56-62
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• 2022

This study analyzed the output precision of 3D printing methods. The inner impeller of the centrifugal compressor was printed in as a sheet with 100% packing density using two methods: field deposition modelling and stereolithography. Dimensional differences between the initial CAD and printed models were evaluated using a 3D scanner. To investigate the dimensional characteristics of the 3D printed impeller, 3D dimension analysis and point dimension analysis were performed. The point dimension analysis was divided into 3D and 2D for comparative analysis.

• 한국전산유체공학회:학술대회논문집
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• 2006.05a
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• pp.311-314
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• 2006

The supersonic flow around tandem cavities was investigated by three- dimensional numerical simulations using the Reynolds-Averaged Navier-Stokes(RANS) equation with the $\kappa-\omega$ thrbulence model. The flow around a cavity is characterized as unsteady flow because of the formation and dissipation of vortices due to the interaction between the freestream shear layer and cavity internal flow, the generation of shock and expansion waves, and the acoustic effect transmitted from wake flow to upstream. The upwind TVD scheme based on the flux vector split using van Leer's limiter was used as the numerical method. Numerical calculations were performed by the parallel processing with time discretizations carried out by the 4th-order Runge-Kutta method. The aspect ratio of cavities are 3 for the first cavity and 1 for the second cavity. The ratio of cavity interval to depth is 1. The ratio of cavity width to depth is 1 in the case of three dimensional flow. The Mach number and the Reynolds number were 1.5 and $4.5{\times}10^5$, respectively. The characteristics of the dominant frequency between two-dimensional and three-dimensional flows were compared, and the characteristics of the second cavity flow due to the fire cavity flow cavity flow was analyzed. Both two dimensional and three dimensional flow oscillations were in the 'shear layer mode', which is based on the feedback mechanism of Rossiter's formula. However, three dimensional flow was much less turbulent than two dimensional flow, depending on whether it could inflow and outflow laterally. The dominant frequencies of the two dimensional flow and three dimensional flows coincided with Rossiter's 2nd mode frequency. The another dominant frequency of the three dimensional flow corresponded to Rossiter's 1st mode frequency.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.1105-1108
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• 1999

In this paper, we propose a new addressing mode, which can be used for programmable image processor to perform image- processing algorithms effectively. Conventional addressing modes are suitable for one-dimensional data processing such as voice, but the proposed addressing mode consider two-dimensional characteristics of image data. The proposed instruction for two-dimensional addressing requires two operands to specify a pixel and doesn't require any change of memory architecture. Combining several instructions to load a pixel-data from an external memory to a register, the proposed instruction reduces code size so that satisfy hish performance and low power requirements of image processor. In addition, it uses inherent two-dimensional characteristics of image data and offers user-friendly instruction to assembler programmer.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.9
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• pp.661-667
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• 2002

With the increase of storage density, high rotational speed and high access technologies in optical disk drive, mechanical issues, mainly noise and vibration, become critical. Up to now the researches of rubber mount for anti-vibration focused on how to calculate the static and the dynamic stiffness of rubber mount and loaned out consideration of the dimensional tolerance of rubber mount for anti-vibration. This paper presents the effects of dimensional tolerance of rubber mount for anti-nitration on the dynamic characteristics of optical disk drive by finite element analysis and dynamic test. The relation between dimensional tolerance and dynamic characteristics of optical disk drive is observed and discussed.

• Proceedings of the Optical Society of Korea Conference
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• 2005.07a
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• pp.204-205
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• 2005

Studies on display has been requested some major changes due to the high growth of the handheld terminal market. Therefore, the self emitting OLED(Organic Light Emitting Diode) has been interested as a next generation flat plane display because of its preeminent characteristics such as quick response characteristics, higher performance viewing angle, low power consumption, and panel floating. However, a trend of the display market is moving to three dimensional image processing instead of two dimensional flat display and various researches on display using hologram makes up for the difficulty in three dimensional display using typical flat display. In this study the Lenticular Screen Printing method is presented so that it can be applicable to organic semiconductor display devices and makes possible three dimensional display using flat display for complement the drawback of inorganic semiconductor.

• Proceedings of the Korea Society of Design Studies Conference
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• 2005.05a
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• pp.220-221
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• 2005

• Korean Institute of Interior Design Journal
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• v.26 no.2
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• pp.55-63
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• 2017

Recent projects of Japanese architect, Ito Toyo have been evolved into innovative and experimental stages that are unique and different from other contemporary architects. Since Ito established his own office in 1971, there were several critical changes and developments in terms of architectural philosophy as well as design methods. Particularly, after Sendai Mediatheque, Ito has tended to focus on creating three-dimensional organic body in which architectural form, space, structure, facilities, images are merged all together. With this new type of three-dimensional structure, Ito aims to generate a new notion of architecture as 'living organism'. This paper tried to analyze Ito's new concept of architecture, design process of three-dimensional organic body and its ultimate characteristics and meanings. For the analysis, three projects were selected: Taichung Metropolitan Opera House(2005), Berkeley Art Museum and Pacific Film Archive(2007), The New Deichman Library in Oslo(2008). These projects clearly represent several types of three-dimensional organic body. After the comparative studies, it is found that, in Ito's design process and method, there are unique characters: ambivalent relationship between plan and three-dimensional form, aiming new/hyper reality through complicated collaboration of analogue and digital design tools, and contradictory relationship with surrounding urban context. Although there are some limitations and restrictions, ever-evolving Ito's design concept and methods are very much valid and meaningful in contemporary spatial design in various perspectives.