• Spatial Information Research
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• v.8 no.2
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• pp.243-255
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• 2000

The spatial distribution characteristics and patterns of geographic features in space can be understood through a variety of analysis techniques. The scale is one of most important factors in spatial analysis techniques. This study is aimed at identifying the characteristics of spatial data with a coarser spatial resolution and finding procedures for spatial resolution in operational scale. To achieve these objectives, this study selected LANSAT TM imagery for Sunchon Bay, a coastal wetland for a study site, applied the indices for representing scale characteristics with resolution, and compared those indices. Local variance and fractal dimension developed by previous studies were applied to measure the textual characteristics. In this study, Moran s I was applied to measure spatial pattern change of variance data which were generated from the process of coarser resolution. Drawing upon the Moran s I of variancedata was optimum technique for analysing spatial structure than those of previous studies (local variance and fractal dimension). When the variance data represents maximum Moran´s I at certainly resolution, spatial data reveals maximum change at that resolution. The optimum resolution for spatial data can be explored by applying these results.

• Proceedings of the Korea Multimedia Society Conference
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• 1998.04a
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• pp.128-132
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• 1998

유방암의 조기진단을 위한 수단으로 Mammography의 x-선 film-screen이 많이 사용된다. 그러나, Mammogram에서 정상조직과 암조직 간의 대조도 차이가 크지 않으므로 판독은 그다지 쉽지가 않다. 이러한 문제들의 해결을 위하여 mammogram의 디지털 화상처리 및 분석 연구가 활발히 진행 중이다. 본 연구에서는 진단방사선의들이 필름을 판독할 때 시각적인 인지도를 높여주고, 보다나은 의료지원 서비스의 제공을 위한 목적으로, 유방암의 조기진단의 중요한 요소인 미세석회의 검출을 위한 방법으로서 fractal dimension을 구하여 종괴와 미세석회, 미세석회에 대한 차이를 분석하고자 하였다. 각각의 실험군에 대하여 30명씩 60명의 데이터를 0.1mm resolution의 12bit gray scale로 획득하여 사용하였는데, 일차로 화상의 대조도 개선을 위하여 처리를 하였고 화상의 분석으로 강조된 화상의 불규칙정도 및 거친 정도를 나타내기 위하여 fractal dimension을 계산하였다. 원화상에서 가시적으로 분간하기 힘들었던 병변을 화상처리를 통해 강조된 화상에서는 쉽게 그 특징을 볼 수 있었다. 실제로 mammogram을 진단할 때, 강조화상으로 미세석회와 같은 조기진단의 가시적인 판단을 도모할 수 있으며, 미세석회의 진단에서 fractal dimension값을 이용하여 병변 특성의 하나로서 사용할 수 있을 것으로 판단된다.

• The Journal of the Korea Contents Association
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• v.10 no.3
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• pp.215-221
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• 2010

To assess the clinical value of time resolved imaging of contrast kinetics(TRICKS) MRA by comparison with conventional time of flight(TOF) MR angiography. Both TOF-MRA and TRICKS-MRA were performed in 17 patients with cerebrovascular disease and in 6 patients with brain tumor. Among 17 cerebraovascular patients, digital subtraction angiography(DSA) data were also obtained in 11 patients. TOF-MRA showed good spatial resolution but short in temporal resolution. Although TRICKS-MRA showed somewhat low spatial resolution, it showed superior temporal resolution by distinguishing vessel and tumor in all patients. Also, from the analysis of vessel-tumor relationship, TRICKS-MRA showed better performance than TOF-MRA. TRICKS-MRA makes it possible to image arterial, capillary and venous phase sequentially with very speedy manner and therefore, the clinical use of this method is highly suggestive for future use.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.315-318
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• 1988

THE STUDY ABOUT CHARACTERISTICS OF PHOTO RESIST ITSELF (MINIMUM RESOLUTION, DEPTH OF FOCUS MARGIN AND CRITICAL DIMENSION CONTROL LATITUDE) WAS DONE AND REPORTED. THREE TYPES OF PHOTO RESISTS WERE TESTED. THE FIRST IS THE LOW MOLECULAR WEIGHT PHOTO-RESIST SHOWING THE NARROW DISTRIBUTION OF MOLECULAR WEIGHT (LOW MOLECULAR WEIGHT CONTROL TYPE), THE SECOND IS A PHOTO-RESIST CONTAINING THE INNER CONTRAST ENCHANCEMENT MATERIAL (INNER CEM TYPE) AND THE THIRD IS A NORMAL PHOTO-RESIST (HIGH MOLECULAR WEIGHT TYPE). THE INNER CEM TYPE AND THE LOW MOLECULAR WEIGHT CONTROL TYPE PHOTO-RESIST ARE MORE IMPROVED PHOTO-RESISTS. IT PROVED THAT THE MINIMUM RESOLUTION WAS IMPROVED BY 0.2 - 0.3 um, THE DEPTH OF FOCUS MARGIN WAS IMPROVED BY 0.8 - 1.2 um AND THE C.D. CONTROL LATITUIDE WAS IMPROVED.

• Communications of the Korean Mathematical Society
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• v.12 no.4
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• pp.829-839
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• 1997

We study the Betti numbers, the Bass numbers and the resolution of modules under the change of rings. For modules of finite homological dimension, we study the Euler characteristic of them.

• The Journal of the Acoustical Society of Korea
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• v.22 no.1
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• pp.35-41
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• 2003

Feature vectors for conventional speech recognition are usually extracted in full frequency band. Therefore, each sub-band contributes equally to final speech recognition results. In this paper, feature Teeters are extracted indepedently in each sub-band. The cepstral resolution of each sub-band feature is controlled for the optimal speech recognition. For this purpose, different dimension of each sub-band ceptral vectors are extracted based on the multi-band approach, which extracts feature vector independently for each sub-band. Speech recognition rates and clustering quality are suggested as the criteria for finding the optimal combination of sub-band Teeter dimension. In the connected digit recognition experiments using TIDIGITS database, the proposed method gave string accuracy of 99.125%, 99.775% percent correct, and 99.705% percent accuracy, which is 38%, 32% and 37% error rate reduction relative to baseline full-band feature vector, respectively.

• Smart Structures and Systems
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• v.13 no.6
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• pp.975-991
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• 2014

The objective of this study is to develop a reliable method for locating cracks in a beam using data fusion of fractal dimension features of operating deflection shapes. The Katz's fractal dimension curve of an operating deflection shape is used as a basic feature of damage. Like most available damage features, the Katz's fractal dimension curve has a notable limitation in characterizing damage: it is unresponsive to damage near the nodes of structural deformation responses, e.g., operating deflection shapes. To address this limitation, data fusion of Katz's fractal dimension curves of various operating deflection shapes is used to create a sophisticated fractal damage feature, the 'overall Katz's fractal dimension curve'. This overall Katz's fractal dimension curve has the distinctive capability of overcoming the nodal effect of operating deflection shapes so that it maximizes responsiveness to damage and reliability of damage localization. The method is applied to the detection of damage in numerical and experimental cases of cantilever beams with single/multiple cracks, with high-resolution operating deflection shapes acquired by a scanning laser vibrometer. Results show that the overall Katz's fractal dimension curve can locate single/multiple cracks in beams with significantly improved accuracy and reliability in comparison to the existing method. Data fusion of fractal dimension features of operating deflection shapes provides a viable strategy for identifying damage in beam-type structures, with robustness against node effects.

• Journal of the Korean Mathematical Society
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• v.39 no.4
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• pp.611-620
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• 2002

The aim of the Paper is to Obtain information about the flat covers and minimal flat resolutions of Artinian modules over a Noetherian ring. Let R be a commutative Noetherian ring and let A be an Artinian R-module. We prove that the flat cover of a is of the form $\prod_{p\epsilonAtt_R(A)}T-p$, where $Tp$ is the completion of a free R$_{p}$-module. Also, we construct a minimal flat resolution for R/xR-module 0: $_AX$ from a given minimal flat resolution of A, when n is a non-unit and non-zero divisor of R such that A = $\chiA$. This result leads to a description of the structure of a minimal flat resolution for ${H^n}_{\underline{m}}(R)$, nth local cohomology module of R with respect to the ideal $\underline{m}$, over a local Cohen-Macaulay ring (R, $\underline{m}$) of dimension n.

• Journal of the Semiconductor & Display Technology
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• v.15 no.3
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• pp.1-5
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• 2016

In order to apply sub-resolution assist feature (SRAF) in extreme ultraviolet lithography, the maximum non-printing SRAF width and lithography process margin needs to be improved. Through simulation, we confirmed that the maximum SRAF width of 6% attenuated phase shift mask (PSM) is large compared to conventional binary intensity mask. The increase in SRAF width is due to dark region's reflectivity of PSM which consequently improves the process window. Furthermore, the critical dimension error caused by variation of SRAF width and center position is reduced by lower change in diffraction amplitude. Therefore, we speculate that the margin of SRAF application will be improved by using PSM.

• Journal of Korea Multimedia Society
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• v.6 no.5
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• pp.769-777
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• 2003

We present a striping technique that MPEG-1 video streams ell a disk array can be efficiently played back at different resolution levels. For the MPEG-1 compression algorithm, the proposed multi-level encoding technique first partitions the parent video stream in the temporal dimension. Each frame in the sub-stream is then Partitioned in the chroma dimension yielding a low resolution and a residual component. The multimedia server stores blocks of different components on consecutive disks in a round robin manner. As a result, the lower the resolution level being maintained, the smaller is the number of disks accessed by each client. To effectively utilize a disk array and to maximize the number of clients that can be serviced simultaneously, the proposed technique interleaves the storage of the component of sub-streams among the disks in the array We empirically validate and evaluate this striping technique through simulation in order to show the improvement of its performance on the server.