• Spatial Information Research
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• v.14 no.1 s.36
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• pp.163-176
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• 2006

The concept of 'spatial association' explains spatial distribution pattern of geographical phenomenon based on similarity with neighborhoods, as in the Tobler's Law of Geography: 'Everything is related to everything else, but near things are more related than distant things.' In this study, we develop a time-series exploratory analysis tool for discovering temporal patterns of spatial association by combining spatial statistics and geo-visualization, and thus present a possibility to support spatial decision-making process. As for the spatial proximity weight matrix indispensable to measuring global and local spatial association, we employ a variety of flexible weighting schemes using geometric characteristics of areal unit. In addition, we renovate the existing visualization methods for more effective understanding of the procedures and results of time-series analysis on spatial association: for instance, temporal parallel coordinate plot with box plot, animated map for spatial association, and 3D Moran scatterplot. The feasibility of our system is verified by time-series analysis experiments on the spatial association of land price fluctuation rate for all administrative units in Korea, $1995{\sim}2004$.

• Composites Research
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• v.12 no.1
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• pp.47-58
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• 1999

This paper describes the results of experiments to analyze the free vibration of the laminated composite and hybrid composite plates with various shapes and boundary conditions. The materials of specimens were the carbon fiber reinforced plastic (CFRP), the glass fiber reinforced plastic (GFRP), the GFRP-Aluminum hybrid composite and the CFRP-CFRP hybrid composite. The natural frequencies and nodal patterns of plates with various shapes were experimentally obtained by impact exciting test using an impact hammer and an accelerometer. The experimental results were presented with normalized frequency parameters. The effects of composite material properties, fiber orientation angles, various geometrical shapes and boundary conditions on the vibration characteristics of composite plates were evaluated. To compare and verify these experimental results, the finite element analysis was carried out, and was well agreed with experimental results.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.2
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• pp.285-290
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• 2009

An association rule mining has been studied to find hidden data pattern in data mining. A realization of fast processing method have became a big issue because it treated a great number of transaction data. The time which is derived by association rule finding method geometrically increase according to a number of item included data. Accordingly, the process to reduce the number of rules is necessarily needed. We propose the T-algorithm that is efficient rule reduction algorithm. The T-algorithm can reduce effectively the number of association rules. Because that the T-algorithm compares transaction data item with binary format. And improves a support and a confidence between items. The performance of the proposed T-algorithm is evaluated from a simulation.

• Journal of the Korea Computer Graphics Society
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• v.30 no.2
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• pp.1-9
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• 2024

In this paper, we propose a new method to visualize different vector field patterns from density data. We use moving least squares (MLS), which is used in physics-based simulations and geometric processing. However, typical MLS does not take into account the nature of density, as it is interpolated to a higher order through vector-based constraints. In this paper, we design an algorithm that incorporates Monte Carlo-based weights into the MLS to efficiently account for the density characteristics implicit in the input data, allowing the algorithm to represent different forms of white noise. As a result, we experimentally demonstrate detailed vector fields that are difficult to represent using existing techniques such as naive MLS and divergence-constrained MLS.

• Journal of Korea Multimedia Society
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• v.4 no.3
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• pp.247-256
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• 2001

Digital watermarking is a copyright protection technique for digital images which embed a code into the digital data so the data is marked. Watermarking techniques previously deal with on-line digital data and have been developed to withstand digital attacks such image processing, compression and geometric transformation. In this paper we propose a novel method of embedding watermarks in printed images. In the proposed algorithm, watermark is embedded in a dithered binary image by comparing the $2\times{2}$ blocks of the counting array is the number of 1 (WHITE) in the $16\times{16}$ blocks of the dithered binary image with predefined reference block pattern, which is generated by watermark values. The proposed algorithm is able to provide more information at a watermark because the proposed algorithm use both '1'and '0' as watermark values. The watermark information is detected by comparing the watermark which is reconstructed from the image which is embedded watermark with the original watermark which is embedded in a binary image. The performance of the proposed algorithm is compared with that of the conventional watermark embedding algorithm for printed images by detecting watermark for scan images.

• Journal of the Korea Convergence Society
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• v.8 no.8
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• pp.71-75
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• 2017

Due to the spread of SNS, web-based consumer-generated data is increasing exponentially. It is important in many fields to accurately extract what is appropriate for the user's interest in a large amount of data. It is especially important for business mangers to establish marketing policies to find the right customers for them in many users. In this paper, we try to obtain important information centering on customers who are interested in each account through Twitter follow - following relationship. Because Twitter's current follower relationships do not reflect the user's interests, we try to figure out the details of interest using keyword extraction methods for tweets of followers. To do this, we select two domestic commercial Twitter accounts and apply the sequential pattern evaluation index to the mining key phrase of the text data collected from the follower.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1194-1199
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• 2007

본 연구에서는 도시배수관망의 간략화 모의 시 지선을 단순 생략하는 것이 아니라 2차원 관망을 1차원으로 전환시키는 방법인 등가하천 개념을 도입하여 도시유역의 유출량 산정에 있어서 여러 지선들을 개별적으로 모의하지 않으면서도 실제 존재하는 지선들의 효과를 고려할 수 있는 방법을 개발하고자 하였다. 자연하천에 대해 개발된 등가하천 개념은 최근의 수문모형의 경향인 물리적 분포형 모형의 복잡성을 피하면서 전통적인 개념적 집중형 모형이 가지는 간편성을 살리고 그 것이 가지고 있는 선형가정의 한계를 극복하기 위한 방안으로서 제안된 방법이다. 등가하천 개념을 도입하여 개발된 모형은 종국적으로 강우-유출관계에 있어서 강우의 크기, 선형 및 비선형성, 유역면적 등이 미치는 영향을 분석하기위한 도구로 개발되었으며, 본 연구에서는 출구로부터 동일 거리 s에 위치한 지점에서의 배수관망의 공간적인 분포 및 집중패턴을 파악하는 폭함수(width function, n(s))와 면적함수(area function, M(s))를 이용하여 관망을 간략화 하였다. 등가관의 수리기하조건 결정은 유역이 정상상태에 도달했을 경우에 대해서 이루어지게 되며 정상상태 모의를 통해 개별 관망단면들에 대해 얻어진 유량(Q), 면적(A), 수심(y) 자료간의 상관관계를 유추하여 Q(A), A(y) 함수를 유도하게 되면 종국적으로 관로홍수추적에 이용되는 지배방정식의 매개변수인 파속계수(c) 및 확산계수(D)를 계산할 수 있게 된다. 본 연구에서는 대상 유역으로 군자 배수구역을 선정하여 유역의 특성과 관망 자료를 수집하고 간략화 기법을 적용한 결과를 분석 하였다.다. 21세기 문화산업에서 우리가 판단하게 될 디자인의 가치는 계몽의 원리에 대한 '역사성'과 '현재성'의 변증법에 달려있는 것이며, 새로운 철학, 새로운 문명, 새로운 세계를 열어가는 것이다.r$ (地理志)에는 추현리와 이미 외리를 언급하면서 상주의 자기제작의 위상을 짐작하는 기록이 언급되면서 전국의 상품의 절반을 담당하고 있었음을 알 수 있었다. $\ulcorner$경상도지리지$\lrcorner$(慶尙道地理志)에는 상주가 8곳으로 1/3의 자기 생산을 담당하고 있었다. $\ulcorner$경상도지리지$\lrcorner$(慶尙道地理志)에는 $\ulcorner$세종실록$\lrcorner$(世宗實錄) $\ulcorner$지리지$\lrcorner$(地理志)와 동년대에 동일한 목적으로 찬술되었음을 알 수 있다. $\ulcorner$경상도실록지리지$\lrcorner$(慶尙道實錄地理志)에는 $\ulcorner$세종실록$\lrcorner$(世宗實錄) $\ulcorner$지리지$\lrcorner$(地理志)와의 비교를 해보면 상 중 하품의 통합 9개소가 삭제되어 있고, $\ulcorner$동국여지승람$\lrcorner$(東國與地勝覽) 에서는 자기소와 도기소의 위치가 완전히 삭제되어 있다. 이러한 현상은 첫째, 15세기

• Journal of the Korea Fashion and Costume Design Association
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• v.11 no.3
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• pp.101-110
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• 2009

Danchung(丹靑) is the traditional Korean patterns that are decorated with various colorful patterned paintings upon each sections of wooden architecture. Although Danchung consists of variety patterns with the meaningful signs and symbols, as an accomplishment of Korean traditional images, there is a few fashion merchandise by Danchung patterns. Therefore, the purpose of this study is about to design Jacquard fabrics, and to develop bags of Jacquard fabric by Danchung patterns, as a differentiated cultural Fashion Merchandise. The theoretical background was researched for the geometric image of Danchung patterns on the basis of the basic elements, compositions and symbolic meanings of Danchung. The geometric image of Danchung patterns, which had the shape of circle, triangle, square and hexagon, was designed to the surface design by Jacquard CAD system(i.e., EAT Designscope by Germany) and woven into Jacquard fabrics by Stabuli electronic Jacquard system. Danchung patterns for fabric design in this study was mainly focused on 'ChipJaGum', 'SamJiChangGum', 'ShouSulGum', Moro patterns of lotus flower(蓮花), Rok-Wha(綠花) and so on. To development bags of jacquard fabric, those woven jacquard fabrics were manufactured to bags by applying the selected of twelve bag-designs among the current bag styles. These manufactured bags of jacquard fabrics in geometric Danchung patterns were appeared a contemporary yet ethnic feeling so that they can be used for the unique korean cultural products to further commercialization.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1997.04a
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• pp.49-61
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• 1997

본 연구에서는 한국에서 구삼각강(1910-1915)과 정밀1차측지망(1975-1994)을 사용하여 지각변동량을 계산하고, 지체구조의 일반적인 변형패턴을 기하학적으로 조사하였다. 본 연구에서는 변형량을 계산하기 위하여 2차원의 무한소 변형모델을 설정하였으며, 수평변형량은 구좌표와 정밀1차측지망의 정밀동시강조정을 자유강조정법에 의하여 최초로 실시하여 일괄성있는 신좌표를 사용하여 계산된 측지선의 변화량으로 추정하였다. 변형설계결과로부터 1910년부터 1994년까지 누적된 변형량은 평균(1.07$\pm$0.5)$\times$10-5이고, 이로부터 년변형속도는 (0.13$\pm$0.063)$\mu$/yr 임을 알 수 있었으며, 변형의 경향을 보면 변형량이 10$\mu$ 보다 큰 값이 한반도의 동해안 지역에 분포하고 있으며, 서부쪽에는 10$\mu$이하의 값이 분포하고 있는 것으로 나타나 한반도의 동해안에서 지진의 발생빈도가 높은 것을 고려한다면 본 연구로부터 계산된 결과는 장래의 연구를 위해 중요한 데이터가 될 것이다. 본 연구에서 얻은 주변형축의 방향은 전국적으로 $77.6^{\circ}$$\pm$$13.5^{\circ}$방향임을 보여주고 있어 한반도의 지각은 ENE~WSW방향으로 압축상태에 있음을 알 수 있었으며, 이 결과는 지질학자나 지진학자들의 연구로부터 얻은 결과와 P-축의 방향이 일치하고 있고, 최대전단변형 이론과 일치하고 있는 것으로 나타났다.

• Computational Structural Engineering
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• v.8 no.3
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• pp.51-57
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• 1995

A simplified stress analysis of perforated plates was carried out using homogenization technique. Homogenization technique, which introduced miroscale expansion in the standard finite element method, reconstructed the plate with regularly placed holes into a set of macroscale and microscale models. The microscale model helped compute homogenized material constants of the unit cell, which were used to compute macroscale displacements in the macroscale model. Also it was possible to compute the stress field of the plate using the microscale model. It was found that reasonable equivalent material constants were computed and that the required degrees of freedom was drastically reduced when homogenization technique was employed in the stress analyses. The microscale modeling in the homogenization technique provided a useful concept of pre- and post-processing in the stress analysis of perforated plates.