• 음성과학
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• 제12권3호
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• pp.79-89
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• 2005

Acoustic feedback between microphone and receiver can be effectively cancelled adaptive feedback cancellation algorithm. Although many speech sounds have non-Gaussian distribution, most algorithms were tested with speech like sounds whose distribution were Guassian type. In this paper, we proposed an adaptive feedback cancellation algorithm based on independent component analysis (ICA) for digital hearing aid. The algorithm was tested with not only Gaussian distribution but also Laplacian distribution. We verified that the proposed algorithm has better acoustic feedback cancelling performance than conventional normalized root mean square (NLMS) algorithm, especially speech like sounds with Laplacian distribution.

• 반도체디스플레이기술학회지
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• 제8권4호
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• pp.95-100
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• 2009

This paper presents an efficient disparity matching, using sum of absolute difference (SAD) and dynamic programming (DP) algorithm. This algorithm makes use of one of area-based algorithm which is the absolute sum of the pixel difference corresponding to the window size. We use the information of the right eye brightness (B) and the left eye brightness to get an best matching results and apply the results to the left eye image using the window go by the brightness of the right eye image. This is that we can control the brightness. The major feature of this algorithm called SAD+DP+B is that although Root Mean Square (RMS) performance is slightly less than SAD+DP, due to comparing original image, its visual performance is increased drastically for matching the disparity map on account of its matching compared to SAD+DP. The simulation results demonstrate that the visual performance can be increased and the RMS is competitive with or slightly higher than SAD+DP.

• 한국정보전자통신기술학회논문지
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• 제13권6호
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• pp.568-574
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• 2020

본 논문에서는 영상처리에 사용되는 Canny edge 검출 알고리즘 중 가장 높은 연산 복잡도를 가진 제곱근 연산 횟수를 감소시키는 방법을 제안한다. 제안하는 방법은 기울기 벡터 연산 과정에 사용되는 제곱근 연산을 이용할 때 일부 픽셀에 특정한 규칙을 사용해 홀을 만들어 제곱근 연산을 직접 하지 않고 주변 픽셀들의 연속성을 이용하여 기울기 벡터를 계산하여 연산 횟수를 감소시킨다. 다양한 테스트 이미지를 이용해 실험한 결과 홀이 1개인 경우 약 97%, 홀을 증가시키면 각각 약 94%, 90%, 88%의 일치율을 보였고, 홀이 1개인 경우에는 0.2ms의 연산시간이 감소되었고, 홀을 증가시키면 각각 약 0.398ms 0.6ms, 0.8ms의 연산시간이 감소되었다. 이를 바탕으로 hole이 2개인 경우 높은 정확도와 연산 수 절감을 통해 저전력 임베디드 비전 시스템을 구현할 수 있을 것으로 기대한다.

• 한국전자파학회논문지
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• 제25권7호
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• pp.782-790
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• 2014

본 논문에서는 바이스태틱 MIMO(Multi-Input Multi-Output) 레이더 시스템에서 다중 신호의 DOA(Direction of Arrival)의 추정을 위한 2차원 Matrix Pencil Method(MPM) 기반 알고리즘을 제안하였다. 2차원 MPM은 낮은 SNR 환경에서도 기존 알고리즘에 비해 적은 연산량으로 다수의 DOA 추정이 가능하고, 송신기에서의 표적 각도인 DOD(Direction of Departure)도 동시 추정이 가능하다. 본 알고리즘의 성능을 확인하기 위해 등간격 선형 배열구조의 MIMO 레이더 시스템에서 SNR에 따른 DOA 및 DOD의 RMSE(Root Mean Square Error)를 확인하였고, 2차원 Capon 기법과 비교하였다.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제11권12호
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• pp.525-530
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• 2022

두 개의 점군(point cloud)을 정렬(alignment)하기 위해 현재까지 ICP(iterative closest point) 알고리즘이 널리 사용되고 있지만, ICP는 두 점군의 초기 방향이 크게 다를 경우 정렬에 실패하는 경우가 많다. 본 논문에서는 두 개의 삼각형 메쉬 A, B가 서로 크게 다른 초기 방향을 가질 때, 이들을 정렬하는 알고리즘을 제안한다. 메쉬 A, B에 대해 각각 가중치 무게중심(weighted centroid)을 구한 뒤, 무게중심으로부터 정점까지의 거리를 이용하여 메쉬 간에 서로 대응될 가능성이 있는 정점들을 특징점으로 설정한다. 설정된 특징점들이 대응될 수 있도록 메쉬 B를 회전한 뒤, A와 B의 정점들에 대해 RMSD(root mean square deviation)를 측정한다. RMSD가 기준치보다 작은 값을 가질 때까지 특징점을 변경하며 같은 과정을 되풀이하여 정렬된 결과를 얻는다. 실험을 통해 ICP 및 Go-ICP 알고리즘으로 정렬이 실패할 경우에도 제안된 알고리즘으로 정렬이 가능함을 보인다.

• Journal of Electrical Engineering and Technology
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• 제10권5호
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• pp.2197-2204
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• 2015

In recent years, medical image diagnosis has growing significant momentous in the medicinal field. Brain and lung image of patient are distorted with salt and pepper noise is caused by moving the head and chest during scanning process of patients. Reconstruction of these images is a most significant field of diagnostic evaluation and is produced clearly through techniques such as linear or non-linear filtering. However, restored images are produced with smaller amount of noise reduction in the presence of huge magnitude of salt and pepper noises. To eliminate the high density of salt and pepper noises from the reproduction of images, a new efficient fuzzy based median filtering algorithm with a moderate elapsed time is proposed in this paper. Reproduction image results show enhanced performance for the proposed algorithm over other available noise reduction filtering techniques in terms of peak signal -to -noise ratio (PSNR), mean square error (MSE), root mean square error (RMSE), mean absolute error (MAE), image enhancement factor (IMF) and structural similarity (SSIM) value when tested on different medical images like magnetic resonance imaging (MRI) and computer tomography (CT) scan brain image and CT scan lung image. The introduced algorithm is switching filter that recognize the noise pixels and then corrects them by using median filter with fuzzy two-sided π- membership function for extracting the local information.

• Journal of Positioning, Navigation, and Timing
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• 제4권3호
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• pp.131-140
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• 2015

Antennas at permanent GPS stations operated by the former Ministry of Government Administration and Home Affairs (MOGAHA) in Korea were replaced in years 2008 and 2009, and these changes caused abrupt discontinuities in precise coordinate time series. In this study, an algorithm that eliminates those breaks was developed based on 15-year-long coordinate time series for the purpose of creating clean and continuous coordinate time series. The newly developed algorithm to correct for sudden jumps and dips in the GPS time series due to the antenna change was designed to consider all the linear and annual signals observed before and after the event. The accuracy of the new algorithm was confirmed to be at the Root Mean Square Error (RMSE) level of 2.3-2.6 mm. The new algorithm was also found to be capable of reflect site-specific characteristics at each station.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(1)
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• pp.292-297
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• 1997

An alternating conditional expectation (ACE) algorithm, a kind of non-parametric regression method, is proposed to generate empirical correlations automatically. The ACE algorithm yields an optimal relationship between a dependent variable and multiple independent variables without any preprocessing and initial assumption on the functional forms. This algorithm is applied to a collection of 12,879 CHF data points for forced convective boiling hi vertical tubes to develop a new critical heat flux (CHF) correlation. The meat root mean square, and maximum errors of our new correlation are -0.558%, 12.5%, and 122.6%, respectively. Our CHF correlation represents the entire set of CHF data with an overall accuracy equivalent to or better than that of three existing correlations.

• 대기
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• 제15권4호
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• pp.203-211
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• 2005

One algorithm has been developed for retrieving aerosol optical thickness from GMS-5 visible channel measurements, and then the algorithm was applied for obtaining the geographical distribution of aerosol optical thickness over East Asia during April 2002. Algorithm employs a look-up table based upon radiative transfer calculations with solar geometry, aerosol optical thickness, and surface albedo as inputs. Validation was conducted by comparing retrieved aerosol optical thickness with measured values from ground-based sky radiation measurements at Anmyon Do, Korea. It was found that the correlation coefficient is 0.71 with -0.03 of bias and 0.34 of root mean square error, suggesting that the algorithm developed in this study can be used for estimating aerosol optical thickness in a quantitative sense.

• 대한기계학회논문집
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• 제17권7호
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• pp.1783-1793
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• 1993

Pattern recognition technique using fuzzy c-means algorithm and multilayer perceptron was applied to classify tool wear states in turning. The tool wear states were categorized into the three regions 'Initial', 'Normal', 'Severe' wear. The root mean square(RMS) value of acoustic emission(AE) and current signal was used for the classification of tool wear states. The simulation results showed that a fuzzy c-means algorithm was better than the conventional pattern recognition techniques for classifying ambiguous informations. And normalized RMS signal can provide good results for classifying tool wear. In addition, a fuzzy c-means algorithm(success rate for tool wear classification : 87%) is more efficient than the multilayer perceptron(success rate for tool wear classification : 70%).