• Proceedings of the Korea Information Processing Society Conference
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• 2004.11a
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• pp.31-34
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• 2004

서브시퀀스 매칭은 시계열 데이터베이스에서 질의 시퀀스와 유사한 서브시퀀스틀 찾아내는 연산이다. 기존의 서브시퀀스 매칭 알고리즘들은 하나의 인덱스만을 사용하여 검색을 수행하기 때문에, 인덱스를 생성하기 위하여 데이터 시퀀스로부터 추출한 윈도우의 크기와 질의 시퀀스의 길이 간의 차이가 커질수록 검색 성능이 급격히 저하되는 문제점을 갖고 있다. 본 논문에서는 이러한 기존 알고리즘의 문제점을 해결하기 위하여 인덱스 보간법에 기반한 새로운 서브시퀀스 매칭 기법을 제안한다. 인덱스 보간법이란 하나 이상의 인덱스를 구축하고 주어진 질의 시퀀스의 길이에 따라 적절한 인덱스를 선택하여 검색을 수행하는 기법이다. 본 논문에서는 서브시퀀스 매칭 비용 공식을 산출하고, 이 비용 공식에 기반하여 제안된 기법의 성능을 최적화 하도록 다수의 인덱스를 구성하는 알고리즘을 제시한다. 마지막으로, 실제 데이터를 이용한 여러 가지 실험을 통하여 제안된 기법의 우수성을 정량적으로 검증한다.

• Spatial Information Research
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• v.19 no.4
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• pp.81-89
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• 2011

This paper presents a multivariate kriging algorithm that integrates categorical data as secondary data for spatial interpolation of sparsely sampled ground survey data. Instead of using constant mean values in each attribute of categorical data, disaggregated local mean values at target grid points are first estimated by area-to-point kriging and then are used as local mean values in simple kriging with local means. This algorithm is illustrated through a case study of spatial interpolation of a geochemical copper element with geological map data. Cross validation results indicates that the presented algorithm leads to significant respective improvement of 15% and 25% in prediction capability, compared with univariate ordinary kriging and conventional simple kriging with constant mean values. It is expected that the multivariate kriging algorithm applied in this study would be effectively applied for spatial interpolation with categorical data.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.15 no.2
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• pp.207-213
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• 1997

The purpose of this study is to aim at presenting efficient technique of 3-D Terrain Modelling through multilateral approach methods and to compare with raw data, using low-densed randomly located point data. The subject religion of this study are selected two sites and take into consideration for degree of freedom about low-densed randomly located point data. The result of this study by precision analysis of digital cartographic map-ping using low-densed randomly located point data bave shown that . First, making digital cartographic map, the technique of making it using low-desned randomly located point data by TIN-based results to good and fast run-time in A and B sites all together. Second, the visualization analysis results of digital cartographic map using TIN and GRID-based terrain modeling techniqus similar exacts A and B sites, but the terrain modeling techniqus by TIN-based are small data size than GRID-based with the data with the data size of saving with DXF files. Third, making digital catographic map using terrain modeling techniques by Grid-based, the standard errors of low-densed randomly located point data and interpolated data using gridding method have more good results by radial basis function interpolation techniques at A and B sites all together.

• Journal of the Korea Society of Computer and Information
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• v.18 no.11
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• pp.59-68
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• 2013

In this paper, an effective scheme was proposed to estimate simple convex surface and simple concave surface which exist in image. This scheme is applied to input image to estimate simple convex surface or simple concave surface. When simple convex surface or simple concave surface exists, another proposed efficient interpolation scheme is used for the interpolated pixel to have the characteristics of simple convex surface or simple concave surface. The magnified image using the proposed schemes is more similar to the real image than the magnified image using the previous schemes. The PSNR values of the magnified images using the proposed schemes are greater than those of the magnified images using the previous interpolation schemes.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.1
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• pp.95-101
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• 2017

In natural images, there is generally locality, and the values of adjacent pixels are similar. It is possible to estimate the curved surface characteristics of the original image using adjacent pixels having similar pixel values. In this paper, after precisely estimating the characteristics of the curved surface existing in the image, interpolation values are obtained so as to faithfully reflect the estimated characteristics of the curved surface, We propose an effective image enlarging method that generates an enlarged image using the obtained interpolation values. The image enlarged by the proposed method maintains the curved surface characteristics of the original image, and thus the image quality of the enlarged image is improved. Experimental results show that the image quality of the proposed method is superior to that of the conventional techniques.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.7C
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• pp.687-696
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• 2009

The motion compensated interpolation method is widely used to increase video frame rates. Especially, the bilateral motion estimation technique provides the improved results, since it doesn't make the overlapping and missing blocks in the interpolated frame. However, the motion vectors, which are obtained by the bilateral motion estimation, sometimes require further correction. In this paper, we propose the efficient motion vector.correction method for the bilateral motion estimation technique. By comparing the motion vectors of neighboring blocks and searching the new motion vector after merging the neighboring blocks, the erroneous motion vectors are efficiently corrected. It is shown that the proposed method provides better results, compared with the conventional methods.

• The Journal of the Acoustical Society of Korea
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• v.20 no.4
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• pp.12-16
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• 2001

To analyze the performance of array shape estimation techniques using auxiliary sensors, the appropriate number and the positions of auxiliary sensors are investigated. Also, a post-processing technique based on spline interpolation is proposed to improve the performance of array shape estimation. The simulation results showed that when auxiliary sensors are arranged uniformly, the performance of shape estimation is better than other arrangements of auxiliary sensors. Also, the proposed post-processing technique improved the performance of the existing shape estimation method, such as Kalman filter method.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.569-572
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• 2001

본 논문에서는 비월주사 방식의 영상을 순차주사 방식의 영상으로 변환하기 위한 deinterlacing 기법에 관하여 고찰한다. 먼저, 공간 영역 상에서 수행되는 기존의 deinterlacing 기법 중에서 우수한 성능을 보이는 것으로 알려진 ELA방법의 단점을 보완하기 위하여 적응적 ELA 알고리즘을 제안하였다. 기존의 ELA방법은 수평 edge를 검출할 수 없어 수평 edge 성분을 포함하는 화소 값은 원치 않는 값으로 보간 되는 결과를 가져왔다. 이를 개선시키기 위해 수평 edge를 효과적으로 검출하는 방법을 제안하고, 수평 에지 부분을 적절히 보간할 수 있는 적응적인 필터를 제안한다. 그 결과 수평 edge 부분에서의 개선으로 기존의 ELA 방법보다 더 나은 성능을 얻었다.

• Journal of Korea Multimedia Society
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• v.16 no.2
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• pp.147-159
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• 2013

In medical visualization, volume visualization is widely used. Applying 3D images to diagnose requires high resolution and accurately implement visualization techniques are being researched accordingly. However, when a three-dimensional image volume visualization is implemented using volume data, aliasing will occur since using discrete data. Supersampling method, getting lots of samples, is used to reduce artifacts. One of the supersampling methods is Catmull-rom spline. This method calculates accurate interpolation value because it is easy to compute and pass through control points. But, Catmull-rom spline method occurs overshoot or undershoot in large gradient of pixel values. So, interpolated values are different from original signal. In this paper, we propose an adaptive adjusting weights interpolation method using Gaussian function. Proposed method shows that overshoot is reduced on the point has a large gradient and PSNR is higher than other interpolated image results.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.6
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• pp.123-131
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• 2009

The emerging display technology has been replaced the previous position of the CRT with the LCD. The nature of hold type display such as LCD, however, causes many problems such as motion blur and motion judder. To resolve the problems, we used frame interpolation technique which improves the image quality by inserting new interpolated frames between existing frames. In this paper, we propose a novel frame interpolation technique that uses dominant MV and variance different value in each block. At first, the proposed algorithm performs unidirectional motion estimation using blocking matching algorithm. The new frame is generated by pixel average using compared block variance or by pixel motion compensation using dominant motion vector, whether the motion estimation find the target area or not. Several experiments with the proposed algorithm shows that the proposed algorithm has better image quality than the existing bidirectional frame interpolation algorithm at the rate of about 3dB PSNR and has low complexity comparing to the unidirectional frame interpolation technique.