• International Journal of Naval Architecture and Ocean Engineering
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• v.3 no.4
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• pp.225-232
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• 2011

In the present study, a new hull panel generation algorithm, namely panel cutting method, was developed to predict flow phenomena around a ship using the Rankine source potential based panel method, where the iterative method was used to satisfy the nonlinear free surface condition and the trim and sinkage of the ship was taken into account. Numerical computations were performed to investigate the validity of the proposed hull panel generation algorithm for Series 60 ($C_B$=0.60) hull and KRISO container ship (KCS), a container ship designed by Maritime and Ocean Engineering Research Institute (MOERI). The computational results were validated by comparing with the existing experimental data.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.1
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• pp.70-81
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• 2019

An improved three dimensional Rankine source method is developed to solve numerically water wave problems in time domain. The free surface and body surface are both represented by continuous panels rather than a discretization by isolated points. The integral of Rankine source 1/r on free surface panel is calculated analytically instead of numerical approximation. Due to the exact algorithm of Rankine source integral applied on the free surface and body surface, a space increment free surface source distribution method is developed and much smaller amount of source panels are required to cover the fluid domain surface than other numerical approximation methods. The proposed method shows a higher accuracy and efficiency compared to other numerical methods for various water wave problems.

• International Journal of Aeronautical and Space Sciences
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• v.8 no.1
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• pp.1-9
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• 2007

As a first step toward a complete CFD-CSD coupling for helicopter rotor load analysis, the present study attempts to loosely couple a CFD code with a source-double panel method. The far-field wake effects were calculated by a time-marching free vortex wake method and were implemented into the CFD module via field velocity approach. Unlike the lifting line method, the air loads correction process is not trivial for the source-doublet panel method. The air loads correction process between the source-doublet method and CFD is newly suggested in this work and the computation results are validated against available data for well-known hovering flight conditions.

• KIEE International Transactions on Electrophysics and Applications
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• v.2C no.6
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• pp.292-296
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• 2002

A new sustain driving method for the AC PDP is presented. In this driving method, the voltage source is connected to a storage capacitor, this storage capacitor charges an intermediate capacitor through LC resonance, and the panel is charged from the intermediate capacitor indirectly. In this way, the current flowing into the AC PDP when the sustain discharge occurs is reduced because the current is indirectly supplied from a capacitor, a limited source of charge. Thus, the input power to the output luminance efficiency is improved. Since the voltage supplied to the storage capacitor is doubled through LC resonance, this method call drive an AC PDP with a voltage source of about half of the voltage necessary in the conventional driving methods. The experiments showed that this charge-controlled driving method could drive ail AC PDP with a voltage source of as low as 107V. Using a panel of the conventional structure, luminous efficiency of 1.28 lm/W was achieved.

• KIEE International Transactions on Electrophysics and Applications
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• v.2C no.5
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• pp.253-257
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• 2002

A new Current-Controlled Driving Method that can drive AC PDPs with low voltage and high luminous efficiency for the sustaining period is presented. In this driving method, the voltage source is connected to a storage capacitor and the stored voltage is delivered to the panel through LC resonance. Thus, this driving method can drive the panel with a voltage source as low as about half of the voltage necessary in the conventional driving methods. The discharge current flowing into the AC PDP is limited in this method. Thus, the power consumption for the discharge is reduced and the discharge input power to output luminance efficiency is improved. Experimental results using this driving method showed that we could drive an AC PDP with a voltage source as low as 146V and that high luminous efficiency of 1.33 1m／W can be achieved.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.11
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• pp.1066-1072
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• 2009

A panel method based on potential flow theory is developed for the steady/unsteady aerodynamic analysis of arbitrary three-dimensional Blended Wing Body aircraft. The panel method uses the piecewise constant source and doublet singularities as a solution. This potential based panel method is founded on the Dirichlet boundary condition and coupled with the time-stepping method. The present method uses the time-stepping loop to simulate the unsteady motion of the aircraft. The present method can solve the three-dimensional flow over the complex bodies with less computing time and provide various aerodynamic derivatives to secure the stability of Blended Wing Body aircraft. That will do much for practical applications such as aerodynamic designs and analysis of aircraft configurations and flight simulation.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.4
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• pp.58-65
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• 1992

In this paper, wave resistance for a submerged body is calculated by a higher order panel method. The Neumann-Kelvin problem is solved by the source or normal dipole distribution method. The body surface is represented by a bicubic B-spline and the singularity strengths are approximated by a bilinear form. The results calculated by the higher order panel method are compared with those by the lowest order panel method developed by Hess & Smith. The convergence rate of the higher order panel method is much better than the lowest order panel method. But the wave resistance calculated by the higher order panel method still shows discrepancy with an analytic solution at low Froude number like that by the lowest order panel method.

• 한국전산유체공학회:학술대회논문집
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• 2006.10a
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• pp.131-135
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• 2006

The aerodynamic characteristics of a T-50 aircraft configuration are investigated by a subsonic panel method. Panel methods are best applicable to the lifting surfaces such as wings and airfoils. Source and doublets are used in the present code as a basic singularities of the panel technique. The panel method is first assessed by applying it to several benchmark problems for which other solutions and experimental data are available, such as a swept wing and wing body configuration. The prediction results are compared with experimental data and show good agreement in all cases considered. Finally, the method is applied to a T-50 aircraft configuration and excellent agreement with flight test data in lift coefficients is found.

• Journal of Korea Multimedia Society
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• v.2 no.1
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• pp.89-98
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• 1999

In this paper, we propose the delta-shaped interpolation method for displaying multi-source video signals on a-Si TFT LCD Panel. The proposed method can be implemented by using less circuits than the conventional methods. Thus it can be applied to the FPD(Flat Panel Display) system without any cost increase such as field memory cost. In order to compare the picture quality of the proposed method with that of the conventional methods, the computer simulation has been executed by checking PSNR, which is especially focused on the edge characteristics. The simulation results show that the proposed method is better than others from the point of view on the edge and local characteristics of the image. Finally, the characteristics and trade-off of the proposed method are discussed.

• Journal of computational fluids engineering
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• v.4 no.1
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• pp.1-7
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• 1999

The numerical methodology for computing tile impact forces and water entry behaviors of high speed water entry bodies was been developed. Since the present method assumed the impact occurs within a very short time interval. the viscous effects do not have enough time to play a significant role in the impact forces, that is, the flow around a water-entry object was assumed as an incompressible potential flow and is solved by the source panel method. The elements fully submerged into the water are routinely treated, but the elements intersected by the effective planar free surface are redefined and reorganized to be amenable to the source panel method. To validate the present code, it was applied to disk, cone and ogive model and compared with experimental data. Good agreement was obtained. The water entry behavior such as the bouncing phenomena from the free surface was also simulated using the impact forces and two degree of freedom dynamic equation. Physically acceptable results were obtained.