• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.372-373
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• 2013

본 논문에서는 전기자동차의 효율적인 구동을 위해 3상 전압 형인버터를 기존 삼각파비교방식의 PWAM 기법을 탈피하고 공간벡터 비교방식의 새로운 PWAM 기법을 제안한다. 공간벡터 변조방식의 장점인 자유도가 높은 특징을 살려 3상 전압형 인버터의 스위칭절환이 최소로 이루어지도록 벡터인가시간과 스위칭 룩업테이블을 설계하고, 시뮬레이션 및 실험 해석을 통해 유효성을 검증한다.

• Journal of Korea Multimedia Society
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• v.10 no.9
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• pp.1135-1142
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• 2007

Front-projection type displays make it difficult to apply traditional skin color detection for human hand because the projected beam not only reaches to the screen but also to the user's hand. This paper solves this problem by modeling the distortion between original image and its final camera input. Our approach improves hand detection rate by modeling of interference effect among color channels and of intra-frame intensity and also by introducing adaptive threshold for color difference in skin region.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.10
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• pp.928-936
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• 2013

3D crosstalk is one of the disturbing things to recognize 3D images. This is caused by the phenomenon that input image for left eye is transferred at the right eye and right eye is transferred at the left eye because of the imperfect isolation by the device characteristics. In this paper, we review the 3D PDP (Plasma Display Panel) operation using active shutter glasses and crosstalk measurement method and investigate the major cause of 3D crosstalk and extend conventional 3D crosstalk using full white and full black image input to Gray-to-Gray (GtoG) 3D crosstalk. We suggest a specific method to reduce Gray-to-Gray 3D crosstalk by using Look up Table (LUT) and sub-field mapping in PDP. And then, we verify the method by measuring GtoG 3D crosstalk rate through specific test images and numerical results.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.5
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• pp.127-135
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• 2010

In motion adaptive temporal noise reduction filtering used for reducing video noises, the strength of motion adaptive temporal filtering should be carefully controlled according to temporal movement. This paper presents a motion adaptive temporal filtering scheme based on least-square training. Each pixel is classified to a specific class code according to temporal movement, and then, an iterative least-square training method is applied for each class code to find optimal filtering coefficients. The iterative least-square training is an off-line procedure, and the trained filter coefficients are stored in a lookup table (LUT). In actual noise reduction filtering operation, after each pixel is classified by temporal movement, simple filtering operation is applied with the filter coefficients stored in the LUT according to the class code. Experiment results show that the proposed method efficiently reduces video noises without introducing blurring.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.5
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• pp.857-864
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• 2006

This paper describes a design of low-power/small-area arithmetic circuits which are vector processing unit powering nit, divider unit and square-root unit for mobile 3D graphic accelerator. To achieve area-efficient and low-power implementation that is an essential consideration for mobile environment, the fixed-point f[mat of 16.16 is adopted instead of conventional floating-point format. The vector processing unit is designed using redundant binary(RB) arithmetic. As a result, it can operate 30% faster and obtained gate count reduction of 10%, compared to the conventional methods which consist of four multipliers and three adders. The powering nit, divider unit and square-root nit are based on logarithm number system. The binary-to-logarithm converter is designed using combinational logic based on six-region approximation method. So, the powering mit, divider unit and square-root unit reduce gate count when compared with lookup table implementation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4C
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• pp.403-413
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• 2009

We compare three predistortion methods to prevent signal distortion and spectral re-growth due to the high PAPR (peak-to-average ratio) of OFDM signal and the non-linearity of high-power amplifiers. The three predistortion methods are pth order inverse, indirect learning architecture and look up table. The pth order inverse and indirect learning architecture methods requires less memory and has a fast convergence because these methods use a polynomial model that has a small number of coefficients. Nevertheless the convergence is fast due to the small number of coefficients and the simple computation that excludes manipulation of complex numbers by separate compensation for the magnitude and phase. The look up table method is easy to implement due to simple computation but has the disadvantage that large memory is required. Computer simulation result reveals that indirect learning architecture shows the best performance though the gain is less than 1 dB at $BER\;=\;10^{-4}$ for 64-QAM. The three predistorters are adaptive to the amplifier aging and environmental changes, and can be selected to the requirements for implementation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.10C
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• pp.1008-1014
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• 2002

This paper is concerned about multiplierless interpolation FIR filters. In this paper, we propose a filter that performs T tap 1:N interpolation FIR filter operation with B-bit inputs without using multipliers. This is done by applying a method which converts a 2s complement multi-bits input to multiple single-bit inputs and a lookup table minimization method which reduces the size of lookup tables by use of the symmetry of filter coefficients and the symmetry of each lookup table. Two FIR filters are implemented using the methods proposed in this paper. Each of the two filters respectively follows the two design parameters in the specification of IMT-2000. Those two FIR filters have an advantage that the number of required gates is reduced up to 70% comparing to that of a conventional transversal FIR filter.

• Journal of Broadcast Engineering
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• v.22 no.6
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• pp.808-816
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• 2017

360 VR video systems has become important to provide immersive effect for viewers. The system consists of stitching, projection, compression, inverse projection, viewport extraction. In this paper, an efficient luminance compensation technique for 360 VR video sequences, where feature extraction and histogram equalization algorithms are utilized. The proposed luminance compensation algorithm enhance the performance of stitching in 360 VR system. The simulation results showed that the proposed technique is useful to increase the quality of the displayed image.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.5
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• pp.105-111
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• 2010

In this paper the elasticity of fault-detection algorithm based on fuzzy logic is proposed through lots of experiments, justifying its validity. The four mathematical morpholgical operators was defined to detect the cracks. The cracks was detected via center of area method with ${\lambda}$-fuzzy measure of fuzzy sets. However generally favorable, the result owes to how adequate the lighting device is designed in case of the so far fine crack of pieces. In an attempt to improve the response of the system, It is designed to minimize the use of memory via LookUp table in software.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.99-104
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• 2011

In this paper the approach of neural network was proposed which detects a variety of defects in the molded parts. In an attempt to improve the response of the system, It is designed to minimize the use of memory via LookUp table in software. The goal of these methods was to extract the features of samples in learning of neural networks, overcoming the algorithms of defects detection and classification. Through the learning of 500 sample patterns of molded parts, defects of 3% molded parts was detected and classified as the incorrect diameter parts. We expect that proposed approach is an effective alternative to save test time and cost for defect detection of a fine pattern within the molded parts.