• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.413-416
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• 2007

Motion-estimation/motion-compensation (ME/MC) provides superior motion picture quality but its huge computation load results in high cost. Impulsive driving is a cost-effective solution but it suffers from large flicker and brightness loss. Motion compensated impulsive driving technology has been developed to achieve high motion picture quality in a cost-effective implementation by combining ME/MC and impulsive driving. The key idea is to apply ME/MC or impulsive driving selectively according to the motion vector distribution of the incoming image sequence. In this paper, the description of the algorithm and the experimental results are provided.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1049-1052
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• 2004

In general, contrary to the CRTs with impulsive emission, liquid crystal displays have motion artifacts such as blurring. ghost image, decrease of dynamic CR(contrast ratio), and stroboscopic motion due to hold type driving method. In this paper, to improve motion picture quality of LCDs. impulsive driving method of black data insertion was applied to the OCB mode which is well known for its fast LC response time and wide viewing angle properties. Subject evaluation was carried out with CRT, TN, SIPS(Super IPS). and impulsive driving OCB. Moving picture image quality near CRT was obtained in impulsive OCB driving mode

• Journal of Information Display
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• v.9 no.1
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• pp.1-5
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• 2008

Two new impulsive driving technologies for 120Hz liquid crystal display (LCD) panels are proposed to improve moving picture quality. One technology generates the dark frame using an adder and a shifter simply without using any look up tables (LUTs). It results in a cost effective impulsive scheme with motion picture quality comparable to that of high speed driving. The other is a backlight flashing method designed to avoid ghost images. The issue of ghost images caused by the slow response time of liquid crystal (LC) is solved by means of 120Hz overdriving and 120Hz backlight flashing. Using the perceived blur edge time (PBET) metric, measured moving picture response time (MPRT) values were 10.8ms and 4.4ms, respectively, while that of 120Hz high speed driving was 10.1ms.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.818-821
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• 2007

Two new impulsive driving technologies for use in 120Hz LCD panels are proposed to improve moving picture quality. One technology generates the dark frame using an adder and a shifter simply without using any LUTs. The other is a backlight flashing method designed to avoid ghost images. Using the PBET metric, measured MPRT values were 10.8ms and 4.4ms, respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.571-574
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• 2002

We propose modified concept that enables LCDs quasi-impulsive operations, and demonstrated a prototype AM-LCD that is suitable for displaying moving pictures combined with '2-Domain Half-V shaped switching mode' FLCD.

• Journal of the korean Society of Automotive Engineers
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• v.15 no.2
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• pp.84-91
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• 1993

The dynamic behaviors of a launcher under impulsive forces are analyzed. All the components of the system, ie ; chassis, turret, cage and suspension parts, are modeled as rigid. The dynamic analysis code, which is developed with the formulae describing the system equations of motion in terms of relative quantities, is used to carry out the analysis. The results show the dynamic responses of chassis and cage when the driving constraints are imposed on turret and cage.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.95-97
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• 2007

Large area flicker is one of the most annoying image defects, and it is an inherent characteristic of impulsively driven displays such as CRTs. Recently, LCDs have also adopted impulsive driving methods for improved motion picture quality, therefore LCDs can also show large area flicker. Existing metrics do not account for the non-linearity of human brightness perception. This paper presents an improved large area flicker metric to more accurately quantify large area display flicker performance.

• Journal of Electrical Engineering and Technology
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• v.1 no.3
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• pp.332-337
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• 2006

In this paper, an electronic ballast was developed to control a 250W metal halide lamp. To avoid acoustic resonance phenomenon, we calculated the acoustic resonance band and determined the driving frequency from 70kHz to 100kHz. Due to the switching loss of MOSFET, many problems are caused in the inverter circuit during lamp lighting, so we reduced the loss by connecting the capacitor that minimizes the magnitude of the impulsive voltage. In this paper, the main point of research is to find the methods to operate the lamp on the rated output power. After detecting the current and the voltage of the lamp, we changed the driving frequency by adjusting the DC voltage level of the VCO input.

• The Journal of the Acoustical Society of Korea
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• v.2 no.1
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• pp.48-58
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• 1983

The transient sound radiation from the impact between a steel ball and a thick plate is analyzed theoretically and compared with experiment results. The derivation process itself is difficult to analyze sound radiation characteristics theoretically for a thick plate with some resonances but may be investigated from measured data. During mechanical impacts, arbitrary driving point importance for an elastic system enables to predict by using mechanical importance method. In order to obtain approximate solution for an impact model testing, the surface Helmholtz integral formulation based on the integral expression for pressure in the field in terms of surface pressure and normal velocity is used as a basis. A simple expression is developed for an impulsive response function, which is time dependent velocity potential and pressure for an impact may then be computed by a convolution of exciting force. In estimating of elastic-acoustical correlation problems, mechanical inertance, overall transfer function and radiation resistance obtained by signal processing techniques are used. The usefulness is confirmed by applying these methods prediction of arbitray driving pint inertance, radiated sound pressure and exciting force.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1995.10a
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• pp.62-67
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• 1995

A method for determining impulsive responses and acoustic radiation for submerged shells of finite length has been presented. The method is a modal-based method, and uses a surface variational principle to obtain data in the frequency domain. The fast Fourier transform technique is used to convert the data to the time domain. The surface pressure responses of a cylindrical shell with endcaps wer compared with those of an infinite shell. It was shown that the surface pressures coincide exactly before any significant reflections from the endcaps occur. Traces of different types of waves were identified from the dispersion relations of the infinite shell. The contributions of flexural and longitudinal waves and these due to the direct radiation from the driving force to the fluid pressure were demonstrated using near-field plots. The exchange of energy between the shell and fluid was examined for shells with and without bulkheads. It was shown that a significant amount of the energy which enters the fluid returns to the shell and most of the energy is dissipated in the shell. It was also shown that the shell with bulkheads radiate significantly more energy into the far-field than the empty shell.