• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.2
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• pp.372-379
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• 2015

The latest video compression standard (such as H.264/AVC and HEVC) utilizes quarter-pel accuracy motion estimation in order to retain detailed motion information. Many sub-pixel motion estimation algorithms used in the spatial domain usually encounters increment of computational complexity due to embedded interpolation algorithm. In this paper, an approach to measure sub-pixel accuracy motion estimation in frequency domain using shifting matrix is proposed. Complexity can be reduced utilizing shifting matrix algorithm in frequency domain and simulation results demonstrate not only higher PSNR but lower bit rates than spatial domain algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.11C
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• pp.917-924
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• 2008

Motion estimation and compensation in the spatial domain check the searching area of specified size in the previous frame and search block to minimize the difference with current block. When we check the searching area, it consumes the most encoding times due to increasing the complexity. We can solve this fault by means of motion estimation using shifting matrix in the transform domain instead of the spatial domain. We derive so the existed shifting matrix to a new recursion equation that we decrease more computations. We modify simply vertical shifting matrix and horizontal shifting matrix in the transform domain for motion estimation of half-pixel accuracy. So, we solve increasing computation due to bilinear interpolation in the spatial domain. Simulation results prove that motion estimation by the proposed algorithm in DCT-based transform domain provides higher PSNR using fewer bits than results in the spatial domain.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.854-859
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• 2001

An eigenvalue analysis of a tunable micro-mechanical actuator is presented. The actuator is modeled as a continuum structure. The eigenvalue modified by the tuning voltage is computed through the linearization of the relation between the electrostatic force and the displacement at the equilibrium. A staggered algorithm is employed to perform the coupled analysis of the electrostatic and elastic fields. The stiffness matrix of the actuator is modified at this equilibrium state. The displacement field is perturbed using an eigenmode profile of the actuator. The configuration change of the actuator due to perturbation modifies the electrostatic field and thus the electrostatic force. The equivalent stiffness matrix corresponding to the perturbation and the change in the electrostatic force is then added to stiffness matrix in order to explain natural frequency shifting. The numerical examples are presented and compared with the experiments in the literatures.

• Advances in Energy Research
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• v.1 no.2
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• pp.117-126
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• 2013

In this paper, core-shell semiconductor quantum dots (QDs) CdSeS/ZnS with emission at 490 nm and 450 nm were investigated for their use in luminescent down-shifting (LDS) layers. Luminescent quantum yield (LQY) of the QDs measurements in solution proposed that they were suitable candidates for inclusion in LDS layers. QDs were encapsulated in poly(methyl,methacrylate) (PMMA) polymer matrix and films were fabricated of $134{\pm}0.05$ microns. Selections of organic dyes from BASF Lumogen F range were also investigated for their use as LDS layers; Violet 570 and Yellow 083. The addition of LDS layers containing Violet 570 dye demonstrated a unity LQY when encapsulated within a PMMA matrix. A PV device of an LDS layer of Lumogen Violet 570 deposited on top of a crystalline silicon cell was fabricated where it was demonstrated to increase the efficiency of the cell by 34.5% relative.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.36 no.3
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• pp.221-227
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• 1987

Other problems associated with pole placement have been discussed. A simple algorithm for output feedback pole shifting has been developed. The algorithm is based on minimising an objective function which is the sum of the exponential of the real part of the system colsed loop eigenvalues. It is demonstrated that the algorithm is simple and effective in arriving at a suitable feedback matrix for the control of boiler using only two measurement.

• Journal of Electrical Engineering and Technology
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• v.11 no.4
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• pp.1020-1026
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• 2016

Motion estimation (ME) algorithms supporting quarter-pixel accuracy have been recently introduced to retain detailed motion information for high quality of video in the state-of-the-art video compression standard of H.264/AVC. Conventional sub-pixel ME algorithms in the spatial domain are faced with a common problem of computational complexity because of embedded interpolation schemes. This paper proposes a low-complexity sub-pixel motion estimation algorithm in the transform domain utilizing shifting matrix. Simulations are performed to compare the performances of spatial-domain ME algorithms and transform-domain ME algorithms in terms of peak signal-to-noise ratio (PSNR) and the number of bits per frame. Simulation results confirm that the transform-domain approach not only improves the video quality and the compression efficiency, but also remarkably alleviates the computational complexity, compared to the spatial-domain approach.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.39 no.6
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• pp.24-35
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• 2002

The wavelet transform is combined with the boundary element method (BEM), to solve efficiently the Maxwell's equation and the proposed method is applied to the electromagnetic problem for the analysis of topological effects of phase-shifting masks. The accuracy of the module developed was verified by comparison with both analytic solutions and published results. In addition, it was found that the boundary element method in combination with the wavelet matrix transform would be more efficient than the conventional methods based on the BEM in views of the calculation speed and the usage of computer memory.

• ETRI Journal
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• v.34 no.5
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• pp.727-733
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• 2012

This paper demonstrates a new driving scheme that allows reducing the supply voltage of data drivers for low-power active matrix organic light-emitting diode (AMOLED) displays. The proposed technique drives down the data voltage range by 50%, which subsequently diminishes in the peak power consumption of data drivers at the full white pattern by 75%. Because the gate voltage of a driving thin film transistor covers the same range as a conventional driving scheme by means of a level-shifting scheme, the low-data supply scheme achieves the equivalent dynamic range of OLED currents. The average power consumption of data drivers is reduced by 60% over 24 test images, and power consumption is kept below 25%.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.6
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• pp.8-13
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• 2004

We presented the method to obtain four speckle interferograms with relative phase shift of $\pi$/2 by passive devices such as waveplate and polarizer, calculate the phase at each point of the speckle interferogram in shearography using Wollaston prism, and theoretically demonstrated the feasibility of the unposed method by Jones matrix.

• Journal of the Korean Society for Nondestructive Testing
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• v.25 no.2
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• pp.67-73
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• 2005

The thickness of a Si3N4 thin film with a 100m nominal thickness was measured by use of a Mach-Zehnder interferometer. The map of the phase-delay through the thin film was obtained by an interframe intensity-correlation-matrix method that could elliminate phase-shifting errors. After the spatial phase-shifting errors were treated with a least-squares method, the reference to surface of the phase map was estimated. The overall accuracy of the method was found to be 5nm.