• 한국정보통신학회논문지
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• 제20권3호
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• pp.519-526
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• 2016

해양사고가 빈번히 발생함에 따라 해상교통관제를 통해 항해의 안전성과 효율성을 개선하기 위한 해상 트래픽 모니터링 시스템을 구축할 필요성이 대두되고 있다. 이와 같은 목적을 위해, 최근에 X-대역 해양 레이더는 해수면 정보를 수집하는데 사용하고 있는데, 파랑 정보를 정확하게 측정하여 해상교통관제 영역 내에서 선박의 안전하고 효율적인 움직임을 제공하는 것이 요구된다. 본 논문에서는 세 가지의 다른 해류 속도를 산출하는 방법 즉, 최소자승법을 이용한 방법, 해류 속도를 반복 최소자승 갱신 방법, 가변적인 해류 속도의 정규화된 스칼라 곱을 극대화하여 해류 속도 추정치를 제공하는 방법 등에 대해 부이 데이터와 비교하고, 그런 후에 반복 갱신 방법을 수정하여 초기의 해류 속도를 개선하여 효과적으로 파랑 정보를 예측하도록 설계된다. 다수의 실험을 통하여 제안한 방법은 기존 방식에 비해 파랑 정보를 효과적으로 추출할 수 있음을 보인다.

• 한국측량학회지
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• 제23권4호
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• pp.385-392
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• 2005

본 논문에서는 중력데이터를 사용하여 중력지오이드모델을 개발하고, GPS/Leveling데이터를 사용하여 개선한 KGEOID05모델을 계산하였으며, 그 정밀도를 분석하였다. KGEOID05는 중력지오이드모델에 보정항을 더하여 계산하였으며, 보정항은 GPS/Levelling에 의하여 구한 지오이드고와 중력지오이드고의 차이를 사용하여 모델링 하였다. 모델링을 위한 통계학적 함수는 Markov 2차공분산 함수에 기초한 least squares collocation방법을 사용하였다. 총 373점의 GPS관측점을 보정항 모델링에 사용하였으며, 정밀도분석결과 KGEOID05의 정밀도는 11cm로 계산되었다. $2{\sim}3$점의 수준점에 대한 GPS관측데이터를 사용하여 지역적으로 KGEOID05모델에 대한 fitting을 실시할 경우에 GPS관측에 의한 $2{\sim}3cm$ 정밀도의 표고측정이 가능하다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1601-1606
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• 1991

We present an algorithm to approximate the Voronoi diagrams of 2D objects bounded by algebraic curves. Since the bisector curve for two algebraic curves of degree d can have a very high algebraic degree of 2 * d$^{4}$, it is very difficult to compute the exact algebraic curve equation of Voronoi edge. Thus, we suggest a simple polygonal approximation method. We first approximate each object by a simple polygon and compute a simplified polygonal Voronoi diagram for the approximating polygons. Finally, we approximate each monotone polygonal chain of Voronoi edges with Bezier cubic curve segments using least-square curve fitting.

• Journal of Astronomy and Space Sciences
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• 제8권1호
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• pp.25-51
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• 1991

The spectra of 31 Cygni were taken at the Asiage Observatory in Italy. Reduction was made using the 2nd and 4th order non-linear least square method. Spectral lines which were relatively sharp or strong were identified within the wavelength regions from 3800 to 5100$AA$. Radial velocities and equivalent widths were calculated from the Gaussian Fitting Method for this star. The measured mean radial velocity of 31 Cygni is + 0.5km/sec.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.1390-1393
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• 1987

This paper describes the image data compression based on the image decomposition. We reduced the processing time using the segmentation based on the distribution of grey level, and obtained high compression rate using the Huffman run-length coding for the segmented image, and the 2-Dimensional least square curve fitting and the shift coder for each region.

• Journal of the Korean Data and Information Science Society
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• 제7권2호
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• pp.203-210
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• 1996

A linear neural unit with a modified anti-Hebbian learning rule has been shown to be able to optimally fit curves, surfaces, and hypersurfaces by adaptively extracting the minor component of the input data set. In this paper, we study how to use the robust version of this neural fitting method for linear regression analysis. Furthermore, we compare this method with other methods when data set is contaminated by outliers.

• Journal of information and communication convergence engineering
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• 제7권4호
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• pp.545-550
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• 2009

A method fully utilizing multiscale line filter responses is presented to estimate the point spread function(PSF) of a CT scanner and diameters of small tubular structures based on the PSF. The estimation problem is formulated as a least square fitting of a sequence of multiscale responses obtained at each medical axis point to the precomputed multiscale response curve for the ideal line model. The method was validated through phantom experiments and demonstrated through phantom experiments and demonstrated to accurately measure small-diameter structures which are significantly overestimated by conventional methods based on the full width half maximum(FWHM) and zero-crossing edge detection.

• Structural Engineering and Mechanics
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• 제9권2호
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• pp.141-152
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• 2000

Based on the discussion about some empirical coherency models resulted from earthquake-induced ground motion recordings at the SMART-1 array in Taiwan, and a heuristic model of the coherency function from elementary notions of stationary random process theory and a few simplifying assumptions regarding the propagation of seismic waves, a practical coherency model for spatially varying ground motions, which can be applied in aseismic analysis and design, is proposed, and the regressive coefficients are obtained using least-square fitting technique from the above recordings.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.679-682
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• 1988

From the viewpoint of general recognition system, B-spline is introduced for the approximation and recognition of human profile contours. Profile contour is approximated to the cublic B-spline curve by least square fitting so that B-Spline nodes nearly correspond with the curvature extrema of the contour. This method is designed for the spline to be good features in recognition, and also showed good approximation compared with the variants of B-spline appraximation.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.447-450
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• 1997

Temperature distribution measurements in the mockup apparatus of reactor vessel were performed to determine the effective thermal conductivity of Al powder porous media where stainless steel tubes were installed with different geometry. The temperature distributions at four separated sections with different arrangements of porous media have different slopes according to the geometrical configuration. From the measured temperature distribution, effective thermal conductivity have been derived using the least square fitting method.