• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.3
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• pp.67-72
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• 2019

This paper evaluates the performance of CCA (Compact Constellation Algorithm) adaptive equalization algorithm by varying the step size for minimization of the distortion effect in the communication channel. The CCA combines the conventional DDA and RCA algorithm, it uses the constant modulus of the transmission signal and the considering the output of decision device by the power of compact slice weighting value in order to improving the initial convergence characteristics and the equalization noise by misadjustment in the steady state. In this process, the compact slice weight values were fixed, and the performance of CCA adaptive equalization algorithm was evaluated by the varing the three values of step size for adaptation. As a result of computer simulation, it shows that the smaller step size gives slow convergence speed, but gives excellent performance after at steady state. Especially in SER performance, the small step size gives more robustness that large values.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.627-632
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• 2021

ITL (information-theoretic learning) has been applied successfully to adaptive signal processing and machine learning applications, but there are difficulties in deciding the kernel size, which has a great impact on the system performance. The correntropy algorithm, one of the ITL methods, has superior properties of impulsive-noise robustness and channel-distortion compensation. On the other hand, it is also sensitive to the kernel sizes that can lead to system instability. In this paper, considering the sensitivity of the kernel size cubed in the denominator of the cost function slope, a new adaptive kernel estimation method using the rate of change in error power in respect to the kernel size variation is proposed for the correntropy algorithm. In a distortion-compensation experiment for impulsive-noise and multipath-distorted channel, the performance of the proposed kernel-adjusted correntropy algorithm was examined. The proposed method shows a two times faster convergence speed than the conventional algorithm with a fixed kernel size. In addition, the proposed algorithm converged appropriately for kernel sizes ranging from 2.0 to 6.0. Hence, the proposed method has a wide acceptable margin of initial kernel sizes.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3236-3238
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• 1999

This paper proposes a new face recognition technique in the dynamic link architecture which shows robustness against size variation and distortion. The face recognition technique in the dynamic link architecture so far was not appropriate for the recognition of various size of faces because of the fixed size of the graph and the fixed value of a of the Gabor filter not considering the size of the face. The proposed face recognition algorithm can represent the input facial image by a suitable size of labeled graph, and it can also adjust the dilation width and the height of the vibrating amplitude of the Gabor filter, thus face recognition in the dynamic link architecture is even applicable regardless of the size of the face.

• Journal of the Korean Institute of Navigation
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• v.19 no.3
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• pp.21-28
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• 1995

Mathematical morphology skeleton image processing makes many partial skeleton image planes from an original binary image. And the original binary image can be reconstructed without any distortion by summing the first partial skeleton image plane and each dilated partial skeleton image planes using the same structuring element. Especially compression effects of Elias coding to the morphological globally minimal skeleton(GMS) image, is better than that of PCX and Huffman coding. And then this paper proposes mathematical morphological GMS image processing which can be applied to a binary image transmitting for facimile and big size(bigger than $64{\times}64$ size) bitmap fonts storing in a memory.

• Journal of Welding and Joining
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• v.17 no.1
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• pp.104-115
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• 1999

There have been many studies on the two dimensional thermo-elasto-plastic analysis in welding process, mostly from viewpoint of residual stresses. In this study, the temperature distribution, transient thermal stress, and angular distortion during bead-on-plate gas metal arc welding of rectangular plates were analyzed by using the finite element method. A nonlinear heat transfer analysis was first performed by taking account of the temperature-dependent material properties and convection heat losses on the surface. This was followed by a thermo-elasto-plastic stresses and distortion analysis that incorporates the constrained boundary condition of the two dimensional solution domain to get the three dimensional size effect of the plate. The constrained boundary conditions adopted in this study were the constant displacement condition over the whole two dimensional section for axial movement in the welding direction, and the force boundary condition for rotational movementof the domain around the axis of the welding direction. It could be revealed that the theoretical predictions of the angular distortion have an improved agreement with the experimentally obtained data presented in the previous study.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.3
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• pp.262-268
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• 2010

In this paper, this study restores the distorted image to its original image by compensating for the distortion of image from a fixed-focus camera lens. The various developments and applications of the imaging devices and the image sensors used in a wide range of industries and expanded use, but due to the needs of the small size and light weight of the camera, the distortion from acquiring images of the distorted curvature of the lens tends to affect many. In particular, the three-dimensional imaging camera, each different distortion of left and right lens cause the degradation of three-dimensional sensitivity and left-right image distortion ratio. we approached the way of generalizing the approximate equations to restore each part of left-right camera images to the coordinators of the original images. The adaptive Neuro-Fuzzy Inference System is configured for it. This system is divided from each membership function and is inferred by 1st order Sugeno Fuzzy model. The result is that the compensated images close to the left, right original images. Using low-cost and compact imaging lens by which also determine the exact three-dimensional image-sensing capabilities and will be able to expect from this study.

• The Journal of Korean Institute of Information Technology
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• v.15 no.12
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• pp.157-164
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• 2017

Mobile ECG signal measurement is a technique to measure small signals of several mV, and many studies have been conducted to remove noise including wandering scheme. Removal of the equipotential line noise caused by shaking or movement of the electrode cable is one of the core research contents for the electrocardiogram measurement. In this study, we proposed a modified step-size of combined NLMS(normalized least squares) and DLMS(delayed least squares) adaptive filter to eliminate baseline noise from ECG signals. The proposed method mainly adjusts initial filter step-size to reduce distortion of original ECG signals characteristic after eliminating baseline noise. The modified filter step-size is scaled by filter order size and distortion minimization factor. This method is suitable for portable ECG device with a small processor and less power consumption. This technique also decreases computation time which is essential for real-time filtering. The proposed filter also increase the signal to noise ratio (SNR) compared to conventional NLMS filter.

• Korean Management Science Review
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• v.11 no.3
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• pp.55-65
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• 1994

Given the flow matrix, plant size and department sizes, the algorithms in this paper provide the layout with rectilinear distance. To construct automated facility design, cut tree approach is employed. A branch and bound computer code developed by Tillinghast is modifided to find the feasible fits of departments without shape distortion in the plant rectangle.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.4
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• pp.318-330
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• 2013

This paper presents a high-linearity low-noise small-size programmable gain amplifier (PGA) based on a new low-noise low-distortion differential amplifier and a proposed reconfiguration technique. The proposed differential amplifier combines an inverter-based differential pair with an adaptive biasing circuit to reduce noise and distortion. The reconfiguration technique saves the chip size by half by utilizing the same differential pair for the input transconductance and load-stage, interchangeably. Fabricated in $0.18-{\mu}m$ CMOS, the proposed PGA shows a dB-linear control range of 21dB in 16 steps from -11 dB to 10 dB with a gain error of less than ${\pm}0.33$ dB, an IIP3 of 7.4~14.5 dBm, a P1dB of -7~1.2 dBm, a noise figure of 13dB, and a 3-dB bandwidth of 270MHz at the maximum gain, respectively. The PGA occupies a chip area of $0.04mm^2$ and consumes only 1.3 mA from the 1.8 V supply.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.6
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• pp.591-601
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• 2002

Motion compensation is a powerful method to compress an image sequence. Its main drawback is that once an error is occurred, the error propagates through the frames. Recently, the intra update method was proposed to stop the error propagation at the expense of reduction in compression efficiency. This paper proposes an intra update method based on a rate-distortion optimization in error prone environments. The rate and the distortion are estimated using the Lagrangian optimization to select the coding mode and the quantization step size. The proposed method is applied to MPEG-4 codec, and the experimental results show that it is robust to the error such as packet losses comparing with the conventional ones.