• Journal of computational fluids engineering
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• v.11 no.1 s.32
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• pp.52-56
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• 2006

In this paper a method for analysing aerodynamic characteristics of a rotating parachute in steady descending motion is presented Because of a complex geometric configuration of the parachute associated with side vents and discontinuous skirts, special procedure was adopted to handle the geometry in the analysis. A panel method was successfully applied to the present problem and yielded good results using above procedure. A CFD code using the full Navier-Stokes equations was also applied and produced good results. Parachute free drop and wind tunnel tests were performed to determine the fully developed canopy configuration and aerodynamic characteristics. The method can be used for optimizing the parachute size and side vent configurations.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1603-1605
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• 2002

TFT-LCD is widely used for flat panel display. The large-size TFT-LCD panel requires a high speed driving and various driving methods because of signal delay, which is responsible for the shading effects. In this work, the floating and double driving methods are applied to Pixel Design Array Simulation Tool(PDAST) and the pixel characteristics of TFT-LCD array is simulated. Also, we have implemented the semi-empirical TFT model to PDAST, which makes to obtain a more accurate pixel characteristics.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.2
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• pp.174-185
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• 2002

The automotive industry faces many competitive challenges including weight and cost reduction to meet need for higher fuel economy. Tailored blanks offer the opportunity to decrease door weight, reduce manufacturing costs, and improve door stiffness. Optimization technology is applied to the inner panel of a door which is made by tailored blanks. The design of tailored blanks door starts from an existing door. At first, the hinge reinforcement and inner reinforcement are removed to use tailored blanks technology. The number of parts and the welding lines are determined from intuitions and the structural analysis results of the existing door. Size optimization is carried out to find thickness while the stiffness constraints are satisfied. The door hinge system is optimized using design of experiment approach. A commercial optimization software MSC/NASTRAN is utilized for the structural analysis and the optimization processes.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.8
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• pp.272-281
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• 1999

Cylindrical panels are widely used as aircraft fuselages and rocket etc, and the cutouts for weight reduction or wiring at such structures tend to cause the stress concentration and the local radial displacement so that seriously effect the stability of structures. In this paper, for the cylindrical composite panel with coutout at the center, the buckling and postbuckling behaviour regarding the shape and size of cutout is analyzed by finite element method. Also the lamination mechanism , changing bending stiffness and fiber orientation angle variation are researched to be regarded in studying the laminated composite materials.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.165-166
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• 2000

Spatial independence and temporal stability of flat-panel LCD monitor, LG StudioWorks 500LC, were evaluated. The luminance and chromaticity of stimulus color were measured according to the variation of the size, background color, and location on the screen. The spatial independence at center location is very good and not a limiting factor in its colorimetric characterization, however the spatial non-uniformity is a little severe. The warmup time to stabilize after initial power is about 100 minutes and short-term variance of white stimulus is within 0.1 ${\Delta}E^*\;_{ab}$.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.452-454
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• 2000

In recent years, the Thin Film Transistor Liquid Crystal Display (TFT-LCD) is used in a variety of products as an interfacing device between human and them. Since TFT-LCDs have trend toward larger Panel sizes and higher spatial and/or gray-scale resolution, pixel charging characteristic is very important for the large panel size and high resolution TFT-LCD pixel characteristics. In this paper, both data line precharging method and line time extension (LiTEX) method is applied to Pixel Design Array Simulation Tool (PDAST) and the pixel charging characteristics of TFT-LCD array were simulated, which were compared with the results calculated by both PDAST In which the conventional device model of a-Si TFTs and gate step method is implemented.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.2
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• pp.109-114
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• 2015

We realize a color reflective display without any color filter and sub-pixelation concept, by which the full or single color realization is basically impossible. In this study, we use a 3-electrode on the lower substrate with indium tin oxide (ITO) glass. The width of a rib is $30{\mu}m$, a cell size is $150{\mu}m{\times}150{\mu}m$, and the space of lower electrodes is $10{\mu}m$. To get the single color, we drive this panel by a identical algorithm based on the movement of charged particle in color fluid within a cell with hermetic seal. According to the driving method, the lifetime of panel is different.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.387-392
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• 2003

This study is put a focus on the identification of sound characteristics according to the interior configuration of sound absorption material and air gap. Noise barrier is general consists of front perforated panel, air layer, sound absorption material, air gap and back plate. Noise barrier is required to the NRC value of 0.7. The absorbing performance of the noise barrier relies on the opening ratio of the perforated panel and the efficiency of the absorbing material. This study has observed the effect of opening ratio and hole size, the increase of sound absorbing performance by the configurations of sound absorption material and air gap. New designed noise barrier is achieved the acoustical performance of 0.87 the measurement in a reveration room.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.613-616
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• 1999

An active-matrix LCD using thin film transistors (TFTs)has been widely recognized as having potential for high-quality color flat-panel displays. Pixel-Design Array Simulation Tool (PDAST) was used to profoundly understand the gate signal distortion and pixel charging capability, which are the most critical limiting factors for high-quality TFT-LCDs. Since PDAST can simulate the gate data and pixel voltages of a certain pixel on TFT array at any time and at any location on an array, the effect of the new set of capacitance models on the pixel operations can be effectively analyzed, The set of models which is adopted from VLSI interconnections calculate more precise capacitance. The information obtained from this study could be utilized to design the larger area and finer image quality panel.

• Journal of Information Display
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• v.12 no.1
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• pp.29-35
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• 2011

In this study, plasma display panels with three different cell volumes were prepared by changing the spaces between the vertical barrier ribs into two and three times the reference structure. The discharge gap and area of the segmented ITO electrode were the same for the three cases, and Ne.20%Xe gas was used. The luminance and luminance efficiency were measured using applied voltage variations. The time evolution and intensity distribution of the infrared, which are related to the vacuum ultraviolet, were observed via intensified, charged, coupled device, and the visible-light intensity profiles were observed using PR-900 to analyze the discharge phenomena in the discharge cell.