• 한국산업융합학회 논문집
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• 제24권5호
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• pp.581-587
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• 2021

In recent years, contamination of drinking water sources has emerged as a serious social problem, such as a large number of impurities in tap water or groundwater or the supply of suitable water due to rust of pipes. Although the government and public institutions are implementing various measures to protect water sources, they cannot improve water quality in a short period of time because of the enormous cost involved. Therefore, in recent years, preference has been given to a device that converts tap water, which is hard water, into soft water by installing a separate water softener at the faucet from which tap water is discharged. However, the existing filtration device has a problem that filtration performance is gradually lowered when impurities accumulate in the filter, requiring continuous filter replacement. In this study, the optimal design of the filter housing was performed to develop a water softener that can be washed when impurities accumulate on the filter inside the water softener connected to the faucet. For optimal design of the filter housing, fluid and fluid-structural interaction analysis were performed on the design pressure to determine the shape and thickness of the housing, and design review was performed through prototype.

• 대한전자공학회논문지SP
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• 제39권3호
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• pp.11-22
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• 2002

다중 텍스쳐 영상으로부터 최적의 텍스쳐 특징을 생성하는 최적 필터 설계는 표면, 물체, 모양, 깊이 인식 등을 위한 텍스쳐 분석에 있어서 가장 성능이 뛰어난 기술 중의 하나이다. 그러나 대부분의 최적 필터설계는 많은 복잡한 계산량과 교사적 특성에 의해서 효율적인 텍스쳐 영역의 분할을 수행하지 못하는 실정이다. 따라서 본 논문에서는 다중 텍스쳐 영상에 내재하는 각 텍스쳐들의 공간 주파수 분석에 의한 효율적인 최적 가버필터 설계 방법을 제시한다. 설계된 최적 필터는 "Brodaz texture book"서 발췌한 다양한 형태의 다중 텍스쳐 영상을 생성하여 실험한 후 성공적인 결과를 보인다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.909-913
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• 1998

Transient and static characteristics of HVDC inverter can be analyzed with various simulation tools. For the optimal filter design, various performance criteria are proposed. In this paper, performance index is calculated based on proposed per phase equivalent circuit. Voltage and harmonic and filter power loss are selected as criteria. Optimization procedure is performed to find optimal passive filter parameters. Dynamic characteristics is also analyzed with proposed equivalent circuit.

• 정보처리학회논문지B
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• 제10B권3호
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• pp.311-320
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• 2003

고유의 텍스쳐 성분에만 최적 반응을 하는 최적 필터(optimal filter)는 다중 텍스쳐 영상으로부터 원하는 텍스쳐 성분을 추출하기 위한 가장 뛰어난 기술이다. 그러나 기존의 최적필터 설계 방법들은 영상에 내재된 텍스쳐 정보가 사전에 주어지는 교사적 방법이 대부분이며, 내재된 텍스쳐 인식을 기반으로 하는 완전 비교사적인 방법에 관한 연구는 거의 이루어지고 있지 않은 실정이다. 따라서 본 논문에서는 효율적인 텍스쳐 분석을 위한 비교사 학습 방법과 가버필터의 주파수 대역 통과형 특징을 이용한 새로운 최적 필터 설계 방법을 제안한다. 제안한 방법은 자기조직형 신경회로망에 의해서 영상에 내재된 텍스쳐 영역을 블록 단위로 군화(clustering)하며, 가버필터의 최적 주파수는 인식된 텍스쳐 오브젝트(texture objects)의 공간 주파수를 분석한 최적 주파수에 동조(turning)한다. 그리고 설계된 최적 가버필터의 성능 평가를 위해서는 다양한 형태의 다중 텍스쳐 영상을 생성하여 내재된 텍스쳐 오브젝트를 추출함으로써 성공적인 결과를 보인다.

• 한국전기전자재료학회논문지
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• 제27권5호
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• pp.328-341
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• 2014

The object of this paper is to develop optimal optical filter, which can be used to identify the financial account and read the information. The five factors which affect the performance of the optical filter are identified as optical glass type, existence of Fe, Photo pic coating type, and coating form. In this study we seek to determine the optimal combination for the best design of the optical filter. For each combination, the performances of optical filter are investigated using the proper experimental equipments and methods. White-state voltage, black-state voltage, and black-state error rate are used for the performance measures. Through the statistical analysis of the performance data collected, we have determined the optimal design of the optical filter.

• International journal of advanced smart convergence
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• 제5권4호
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• pp.66-70
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• 2016

When tooth grinding occurs, electrical stimulation is given at the same time, and tooth grinding stops on such stimulation. Electromyography signals are used as control signals of electrical stimulation to disturb tooth grinding. However because of the electrical stimulation, the M-waves are generated and mixed with spontaneous electromyogram. In this study, we designed an optimal filter to remove M-wave and conserve spontaneous electromyogram simultaneously. The inverse power method (IPM) showed that the optimal filter coefficient is the eigenvector corresponding to the minimum eigenvalue of the input covariance matrix. In order to evaluate the performance of the optimal filter, we compared using a conventional band pass filter and adaptive filter using least mean square algorithm. The experimental results show that the optimal filter can effectively remove the M-wave compared to the previously studied prediction error filter.

• 전자공학회논문지B
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• 제30B권5호
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• pp.18-26
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• 1993

This paper presents the design method for two-dimensional FIR digital filter using optimization scheme. The proposed design method is to extend the optimal one-dimensional filter design algorithm proposed by Parks and McClellan to two-dimensional case. When extending one-dimensional design scheme to two-dimensional one, some problems occur. In this paper we solved the problems by using the least square error model, the two-dimensional Lagrange interpolation, and the modified alternation theory. As a result, the equi-ripple FIR filter is obtained that is more optimal and more specific than the conventional methods.

• 한국음향학회지
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• 제18권1호
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• pp.16-24
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• 1999

사다리형 SAW 필터의 개발을 위해서 종래에는 설계변수 하나하나를 변화시켜 시행착오식으로 사양을 만족시키는 값을 찾아야만 하였다. 본 연구에서는 주어진 사양을 만족시킬 수 있는 사다리형 SAW 필터의 패턴을 자동으로 설계하는 최적 설계법을 개발하였다. 우선 Smith 등가회로 해석법을 이용하여 사다리형 SAW 필터용 해석 프로그램을 제작하였으며, 그 프로그램에 의한 시뮬레이션 결과를 실제 제작된 시작품의 성능과 비교해 봄으로써 타당성을 검증하였다. 이 해석 프로그램을 바탕으로 설계변수의 조정에 따른 성능변수의 변화 경향을 분석함으로써 최적 설계 알고리즘을 개발하였으며. 그 타당성 및 효용성을 기 상용화된 제품들에 대해 시험 설계해 봄으로써 증명하였다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.7-12
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• 2009

In JPEG2000, the Cohen-Daubechies-Feauveau (CDF) 9/7-tap wavelet filter adopted in lossy compression is implemented by the lifting scheme or by the convolution scheme while the LeGall 5/3-tap wavelet filter adopted in lossless compression is implemented just by the lifting scheme. However, these filters are not optimal in terms of Peak Signal-to-Noise Ratio (PSNR) values, and irrational coefficients of wavelet filters are complicated. In this paper, we proposed a method to optimize image quality based on wavelet filter design and on wavelet decomposition. First, we propose a design of wavelet filters by selecting the most appropriate rational coefficients of wavelet filters. These filters are shown to have better performance than previous wavelet ones. Then, we choose the most appropriate wavelet decomposition to get the optimal PSNR values of images.

• 대한의용생체공학회:의공학회지
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• 제18권2호
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• pp.113-120
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• 1997

This paper presents an optimal design for the SPECT reconstruction filter, based on a physical limit of SPECT lesion detection capability. To increase the performance of the filter on lesion detectability, the filter design was focused on increasing the local SyW ratio of a threshold lesion, that was determined by minimum detectable lesion size (MDU) from SPECT lesion detectabllity contrast-detail curve. The proposed filter showed flexible window characteristics of resolution recovery and noise smoothing for MDLSs in the resolution-limited and photon-limited regions, respectively, compennting for the relative impact of the main limitation factors on threshold detectability. The simulated results showed good adaptability of the proposed filter to the changes in physical parameters of photon counts, object contrast, and detector system resolution.