• Journal of computational fluids engineering
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• v.3 no.2
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• pp.52-64
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• 1998

Numerical simulations on the flowfield of lifting chamber for Wing-In-Ground vehicle were performed using Fluent/UNS 4.2 software. The trend of lifting force in lifting chamber and parametric study of geometric and fluid variables were primarily investigated. Selected parameters for investigation are inlet velocity, height between chamber and water level, depth of the skirt, location of inlet, variaton of height at bow and stern. Also, air capturing capabilities from downstream of the propeller were evaluated at the air inlet. The lifting force was increased linearly with the increased of inlet velocity and nonlinearly with the decrease of height force was increased with increased depth. It turned out to have very minor effect on lifting force to change the location of air inlet for lifting chamber, installed on top surface. Tilting the vehicle when it was lifted, the lifting forces, generated in each case, showed no appreciable changes.

• Journal of Broadcast Engineering
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• v.23 no.6
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• pp.876-885
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• 2018

Although e-sports broadcasting market based on VR(Virtual Reality) is growing in these days, technology development for securing market competitiveness is quite inadequate in Korea. Global companies such as SLIVER and Facebook already developed and are trying to commercialize 360 VR broadcasting technology which is able to broadcast e-sports in 4K 30FPS VR video. However, 2D video is too poor to use for 360 VR video in that it brings less immersive experience and dizziness and has low resolution in the scene. this paper, we not only proposed and implemented virtual camera technology which is able to capture in-game space as 360 video with 4K 3D by 60FPS for e-sports VR broadcasting but also verified feasibleness of obtaining stereo 360 video up to 4K/60FPS by conducting experiment after setting up virtual camera in sample games from game engine and commercial games.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.3
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• pp.189-194
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• 2014

In this paper, PV modules using a low-temperature conductive film(LT-CF) as a bonding material between a cell and a solder free ribbon were produced and chracterized, which is more environmental-friendly, cost effective and high efficient. Mainly, filed electrical performance of PV modules using three different types of bonding material; a convetional solder ribbon(SR), a LT-CF and a light-capturing Ribbon(LCR) were compared to comfirm the feasibility of LT-CF as a bonding material. The filed test were conducted for 3 months and results were discussed in terms of amount of output energy production and efficiency.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.10
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• pp.150-161
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• 2013

This paper presents a new system which produces high resolution 3D contents by capturing multiview images of an object using multiple cameras, and estimating geometric and texture information of the object from the captured images. Even though a variety of multiview image-based 3D reconstruction systems have been proposed, it was difficult to generate high resolution 3D contents because multiview image-based 3D reconstruction requires a large amount of memory and computation. In order to reduce computational complexity and memory size for 3D reconstruction, the proposed system predetermines the regions in input images where an object can exist to extract object boundaries fast. And for fast computation of a visual hull, the system represents silhouettes and 3D-2D projection/back-projection relations by chain codes and 1D homographies, respectively. The geometric data of the reconstructed object is compactly represented by a 3D segment-based data format which is called DoCube, and the 3D object is finally reconstructed after 3D mesh generation and texture mapping are performed. Experimental results show that the proposed system produces 3D object contents of $800{\times}800{\times}800$ resolution with a rate of 2.2 seconds per frame.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.404-411
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• 2010

The present paper deals with the continuous work of extending multi-dimensional limiting process (MLP), which has been quite successfully proposed on two- and three-dimensional structured grids, onto the unstructured grids. The basic idea of the present limiting strategy is to control the distribution of both cell-centered and cell-vertex physical properties to mimic a multi-dimensional nature of flow physics, which can be formulated as so called the MLP condition. The MLP condition can guarantee a high-order spatial accuracy without yielding spurious oscillations. Recently, MLP slope limiter was proposed based on the MUSCL-type reconstruction in two-dimensional case and it can be readily extended to three-dimensional case. Through various numerical analyses and extensive computations, it is observed that the proposed limiters are quite effective in controlling numerical oscillations and very accurate in capturing both discontinuous and continuous multi-dimensional flow features on 3-D tetrahedral grids.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.593-601
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• 2014

In this study, we investigated the methods of improving the capturing ability of acid fume by assessing the performance of slot-type external hood installed on both sides of an open surface tank for acid washing process. A field survey and the results of computational fluid dynamics revealed that capturing performance of existing hoods is very poor. To solve such problem, 'push-pull hood' that pushes from one side of an open surface tank and pulls on the other side was suggested. The initial prediction was that if a push-pull hood is used, the acid fume of an acid-washing tank surface could be moved towards the hood through the push flow. However, this study has confirmed that if the push flow velocity becomes too high, it could spread to other areas due to flooding from the hood. Therefore, if the push air supply is maintained at around 25 $m^3/min$(push 10 m/s), proper control flow is formed on the surface of a tank and acid fume that stayed at the upper part of the tank is smoothly captured toward the hood, significantly enhancing the capturing performance.

• Journal of Korean Society for Quality Management
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• v.46 no.3
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• pp.551-568
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• 2018

Purpose: This study addressed the relationship between technological innovation activity and management efficiency of Korean automobile firms. We tested the hypothesis of non-liner relationship of innovation activity in relation to management efficiency. Methods: We discussed prior literature in the firm innovation strategy and management efficiency studies to provide better understanding of relationships between technological innovation activity and management efficiency. As a result, we developed develop and tested a model (Inverted-U shaped) capturing the non-linear impact of technological innovation activity. While we used R&D expenditure and patent registration data for measuring firms' innovation activity, management efficiency was evaluated by using DEA(Data Envelopment Analysis). Results: Main findings of our empirical analysis indicated that the relationships between technological innovation activity and management efficiency was inverted U shaped. This implied that the relationship between technological innovation and management efficiency is inverted U-shaped non-linear, with management efficiency increasing up to a point, beyond which higher levels of R&D and patent registration activities led to a decrease in management efficiency. Conclusion: This study empirically assessed the inconclusive findings of previous research in the area of effects of innovation activities in relation to firm performance. The paper also provided theoretical and practical implications for firms who explore efficient strategy to promote the management performance through technological innovation activities. Future research directions with the limitation of the study was discussed.

• The Journal of the Korea Contents Association
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• v.7 no.4
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• pp.160-169
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• 2007

Main problem in the domestic motion capture type production is that motion data are used even in the case when the human sensibility is needed. In other words it fails to give human images to the work, and production method only use motion capture data unconditionally and impetuously. Even though motion capture is effective and are various and applicable to various areas, it would cause enormous lose of capital and manual labor if these problems are not solved. In the present study, we compare motion capture with key animation production and analyze the merits and short comings of them. Also, we analyze them through the actual production and present the efficient method of key animation production when the expensive motion capturing devices are not available.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.1
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• pp.181-187
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• 2012

Various computer-based simulation tools such as 3D-CAD and CAE systems are widely used to design automotive body structure at the early phase of design. Designers must search the optimal solution that satisfies a number of performance requirements by using their tools and a trial-and-error approach. In the previous three reports, a set-based design approach has been proposed for achieving design flexibility and robustness while capturing designer's preference, and its effectiveness has been illustrated with a simple side-door impact beam design problem and real vehicle side-door structure design. This report presents the development of integrated 3D-CAD and CAE system, and the applicability of our proposal for obtaining the multi-objective satisfactory design solutions by applying to an automotive front-side frame.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.67.3-68
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• 2016

We present evidence of the bar driven secular evolution on disks from z~0.8 to z~0.01. Using $3.6{\mu}m$ images of nearby galaxies from the Spitzer Survey of Stellar Structure in Galaxies (S4G) and images from the Cosmological Evolution Survey (COSMOS), we find that barred galaxies show a light deficit in the disk surrounding the bar within the bar radius. We quantify this light deficit and find that galaxies with a stronger bar (longer, higher Bar/T) show a more pronounced light deficit. We examine snapshots from N-body simulations and confirm that as a barred galaxy evolves, the bar becomes longer and the light deficit becomes more pronounced. Theoretical studies have predicted that bars evolve by capturing nearby disk stars and employing them to make the bar more elongated and stronger. Therefore the light deficit in the disk is likely produced by bars, and thus bars play a major role in shaping their host galaxies, redistributing not only the gaseous but also the stellar mass within galaxies, with important consequences to their subsequent evolution.