• Journal of electromagnetic engineering and science
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• v.4 no.1
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• pp.23-29
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• 2004

In this paper we analyze convergence constraints and time constant of IT-LMS algorithm and derive a method of making it's time constant independent of signal power by using input variance estimation. The method for estimating the input variance is to use a single-pole low-pass filter(LPF) with common smoothing parameter value, θ. The estimator is with narrow bandwidth for large θ but with wide bandwidth for small θ. This small θ gives long term average estimation(low frequency) of the fluctuating input variance well as short term variations (high frequency) of the input power. In our simulations of multipath communication channel equalization environments, the method with large θ has shown not as much improved convergence speed as the speed of the original IT-LMS algorithm. The proposed method with small θ=0.01 reach its minimum MSE in 100 samples whereas the IT-LMS converges in 200 samples. This shows the proposed, tap-power normalized IT-LMS algorithm can be applied more effectively to digital wireless communication systems.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.4
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• pp.155-164
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• 2015

In this paper, we propose a new color interpolation method based on trilateral filter approach, which not only preserve the high-frequency components(image edge) while interpolating the missing raw data of color image(bayer data pattern), but also immune to the image noise components and better preserve the detail of the low-frequency components. The method is the trilateral filter approach applying a gradient to the low frequency components of the image signal in order to preserve the high-frequency components and the detail of the low-frequency components through the measure of the freedom of similarity among adjacent pixels. And also we perform Gaussian smoothing to the interpolated image data in order to robust to the noise. In this paper, we compare the conventional demosaicing algorithm and the proposed algorithm using 10 test images in terms of hue MAD, saturation MAD and CPSNR for the objective evaluation, and verify the performance of the proposed algorithm.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.6
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• pp.259-266
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• 2005

Short-term load forecasting algorithm using neural networks and the sensitivity of temperatures in the summer season is proposed. In recent 10 years, many researchers have focused on artificial neural network approach for the load forecasting. In order to improve the accuracy of the load forecasting, input parameters of neural networks are investigated for three training cases of previous 7-days, 14-days, and 30-days. As the result of the investigation, the training case of previous 7-days is selected in the proposed algorithm. Test results show that the proposed algorithm improves the accuracy of the load forecasting.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2732-2734
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• 2000

This paper proposes a path planning algorithm for mobile robots. To generate a minimum-distance path for mobile robots, we use the Genetic Algorithm(GA) and Visibility Graph. After finding a minimum-distance path between a start and a goal point, the path is revised to find the smooth subminimum-distance path by a path-smoothing algorithm. Simulation results show that the proposed algorithms are effective.

• Journal of Navigation and Port Research
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• v.26 no.2
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• pp.209-213
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• 2002

MRA(Multi-resolution analysis) algorithm by Wavelet and morphology with $3{\times}3$ SQ(square) SE(structure element) is efficient to remove ship's radar clutter progressively and enhances detecting performance. Smoothing efficiency of RMM (Recursive mathematical Morphology) is better than that of Morphology. So, to get a better result than that of old algorithms, this paper proposes a new MRA algorithm which uses Wavelet and Recursive mathematical Morphology with $3{\times}3$ RHR(rhombus) SE. Simulation result of the proposed algorithm shows that PSNR is 0.65~1.50db better than that of old method.

• Proceedings of the Korean Statistical Society Conference
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• 2003.10a
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• pp.295-300
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• 2003

공간적으로 영향을 받는 위치에서의 상호 연관성을 고려한 예측모형 중에서 크리깅 (kriging) 방법은 관측된 데이터를 보간(interpolation)하고, 부드럽게 연결(smoothing)하며, 새로운 데이터를 예측(prediction)하는 통계적 모형으로서 많이 활용되고 있다. 크리깅 모형을 적용하기 위해서는 먼저 주어진 두 위치에서의 비연관성을 나타내는 세미베리오그램 (semivariogram)의 3가지 모수(nugget, sill, range)를 추정해야 한다. 본 연구에서는 전역 적 최적화 방법인 유전자 알고리즘(genetic algorithm)을 도입하여 세미베리오그램 모수들을 추정하였고, 이를 통해 강우량(rainfall)에 대한 크리깅 추정량을 산출하고 효과성을 판단하였다.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1189-1191
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• 2005

This paper introduces the least-squares order-recursive lattice (LSORL) Laguerre smoother that has order-recursive smoothing structure based on the Laguerre signal representation. The LSORL Laguerre smoother gives excellent performance for a channel equalization problem with smaller order of tap-weights than its counterpart algorithm based on the transversal filter structure. Simulation results show that the LSORL Laguerre smoother gives better performance than the LSORL transversal smoother.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.3B
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• pp.259-265
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• 2001

도래각 추정을 위한 대표적인 알고리즘으로 고유치 분해방식을 이용한 ESPRIT 알고리즘이 있다. 이 알고리즘은 다중 신호의 도래각을 추정할 수 있을 뿐만 아니라, 낮은 SNR에서 뛰어난 분해능을 가지고 있다. 이러한 뛰어난 추정 능력에도 불구하고, ESPRIT 알고리즘은 서로 주파수와 위상이 같은 coherent 한 신호를 분해하지 못하는 커다란 결점을 가지고 있다. 본 논문에서는 이러한 보완한 개선된 ESPRIT (Modified ESPRIT )알고리즘을 제안한다. 개선된 ESPRIT 알고리즘 기존의 ESPRIT 에 spatial smoothing 방법을 도입하여 구성되어진다. 모의실험결과 개선된 ESPRIT 알고리즘은 coherent 하게 입사하는 신호의 도래각을 분해하는 능력에 있어서 매우 우수한 성능을 갖고 있음을 확인할 수 있다.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.527-529
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• 1986

Measurement and control system of weld pool is comprised of optical devices, image processor, personal computer and welding machine. Combinations of ND and Infrared filters were used to block the intense arc light and to get the clearer image of weld pool. Smoothing operation and conversion to binary data were performed to eliminate the noises and to decrease the processing time. A simple algorithm for feedback control was developed and weld pool size is controlled by welding current which is adjusted automatically with personal computer.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.484-486
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• 2002

주문형 비디오 서비스(VoD: Video on Demand)의 경우 네트워크의 자원 이용도와QoS (Quality of Service)가 보장되도록 구축되어야 한다. 대역폭 스무딩 알고리즘은 주문형 비디오 시스템에서 비디오 데이터를 보낼 경우 비디오의 데이터의 급격한 대역폭의 증가 또는 감소를 최소한 줄이는 기법이다. 본 논문에서는 기존의 대역폭 스무딩 기법과 비디오 압축 기법의 특성을 이용하여 새로운 모델과 스무딩 알고리즘을 제안한다. 제안된 알고리즘의 성능평가를 위해 기존 스무딩 알고리즘의 결과와 비교 분석한다.