• The KIPS Transactions:PartD
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• v.12D no.4 s.100
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• pp.543-552
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• 2005

As random access memory chip gets cheaper, it becomes affordable to realize main memory-based database systems. The disk-based spatial indexing techniques, however, cannot direct apply to main memory databases, because the main purpose of disk-based techniques is to reduce the number of disk accesses. In main memory-based indexing techniques, the node access time is much faster than that in disk-based indexing techniques, because all index nodes reside in a main memory. Unlike disk-based index techniques, main memory-based spatial indexing techniques must reduce key comparing time as well as node access time. In this paper, we propose an efficient spatial index structure for main memory-based databases, called Tmr-tree. Tmr-tree integrates the characteristics of R-tree and T-tree. Therefore, Nodes of Tmr-tree consist of several entries for data objects, main memory pointers to left and right child, and three additional fields. First is a MBR of a self node, which tightly encloses all data MBRs (Minimum Bounding Rectangles) in a current node, and second and third are MBRs of left and right sub-tree, respectively. Because Tmr-tree needs not to visit all leaf nodes, in terms of search time, proposed Tmr-tree outperforms R-tree in our experiments. As node size is increased, search time is drastically decreased followed by a gradual increase. However, in terms of insertion time, the performance of Tmr-tree was slightly lower than R-tree.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.6
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• pp.9-18
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• 2005

This paper proposes the color decomposition method for multi-primary display (MPD) using a 3-dimensional look-up-table (3D-LUT) in a linearized LAB space. The proposed method decomposes conventional three-primary colors into the multi-primary control values of a display device under constraints of tristimulus match. To reproduce images on the MPD, the color signals should be estimated from a device-independent color space, such as CIEXYZ and CIELAB. In this paper, the linearized LAB space is used due to its linearity and additivity in color conversion. The proposed method constructs the 3-D LUT, which contain gamut boundary information to calculate color signals of the MPD. For the image reproduction, standard RGB or CIEXYZ is transformed to the linearized LAB and then hue and chroma are computed to refer to the 3D-LUT. In the linearlized LAB space, the color signals of a gamut boundary point with the same lightness and hue of an input point are calculated. Also, color signals of a point on gray axis are calculated with the same lightness of an input. With gamut boundary points and input point, color signals of the input points are obtained with the chroma ratio divided by the chroma of the gamut boundary point. Specially, for the hue change, neighboring boundary points are employed. As a result the proposed method guarantees the continuity of color signals and computational efficiency, and requires less amount of memory.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.1
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• pp.43-50
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• 2003

Today, the demand of image acquisition systems grows as the multimedia applications go on increasing greatly. Among the systems, film scanner is one of the systems, which can acquire high quality and high resolution images. However due to the nonlinear characteristic of the light source and sensor, colors of the original film image do not correspond to the colors of the scanned image. Therefore color correction mr the scanned digital image is essential in the film scanner. In this paper, polynomial regression method is applied for the color correction to CIE $L^{*}$ $a^{*}$ $b^{*}$ color model data converted from RGB color model data. A1so a film scanner hardware with 12 bit color resolution for each R, G, B and 2400 dpi was implemented by using TMS320C32 DSP chip and high resolution line sensor. An experimental result shows that the average color difference ($\Delta$ $E^{*}$$_{ab}$ ) is reduced from13.48 to 8.46.6.6.6.6.

• The KIPS Transactions:PartD
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• v.13D no.4 s.107
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• pp.477-490
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• 2006

Existing index structures need very much update cost because they repeat delete and insert operations in order to update continuously moving objects. In this paper, we propose a new index structure which reduces the update cost of continuously moving objects. The proposed index structure consists of a space partitioning index structure that stores the location of the moving objects and an auxiliary index structure that directly accesses to their current positions. In order to increase the fanout of the node, it stores not the real partitioning area but kd-tree as the information about the child node of the node. In addition, we don't traverse a whole index structure, but access the leaf nodes directly and accomplish a bottom-up update strategy for efficiently updating the positions of moving objects. We show through the various experiments that our index structure outperforms the existing index structures in terms of insertion, update and retrieval.

• Journal of KIISE
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• v.43 no.5
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• pp.590-595
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• 2016

In this study, we propose an efficient method for monitoring continuous top-k queries. In contrast to the conventional top-k queries, the presented top-k query considers both spatial and non-spatial attributes. We proposed a novel main-memory based grid access method, called Bit-Vector Grid Index (BVGI). The proposed method quickly identifies whether the moving objects are included in some of the grid cell by encoding a non-spatial attribute value of the moving object to bit-vector. Experimental simulations demonstrate that the proposed method is several times faster than the previous method and uses considerably less memory.

• Journal of Korea Spatial Information System Society
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• v.8 no.1 s.16
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• pp.59-75
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• 2006

One of the most challenging and encouraging applications of state-of-the-art technology is the field of traffic control systems. It combines techniques from the areas of telecommunications and computer science to establish traffic information and various assistance services. The support of the system requires a moving objects database system (MODB) that stores moving objects efficiently and performs spatial or temporal queries with time conditions. In this paper, we propose schemes to distribute an index nodes of trajectory based on spatio-temporal proximity and the characteristics of moving objects. The scheme predicts the extendible MBB of nodes of index through the prediction of moving object, and creates a parallel trajectory index. The experimental evaluation shows that the proposed schemes give us the performance improvement by 15%. This result makes an improvement of performance by 50% per one disk.

• Proceedings of the Korea Contents Association Conference
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• 2012.05a
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• pp.307-308
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• 2012

인간은 음에서도 색을 느낄 수 있다. 그리고 청각을 통하여 음의 높고(고음), 낮음(저음), 장(길고), 단(짧음), 맑고, 탁함에 따라 색을 다르게 느낄 수 있다. 이러한 현상을 색청(色聽)이라고 한다. 소리와 색의 연관성에 대하여 선행 연구를 고찰한 결과 색의 3속성 색상, 채도, 명도는 음악의 음계, 옥타브, 음색과 연관성이 있었다. 그리고 음악의 리듬은 조형의 공간, 형태의 조화와 반복이 유사하다는 것을 알 수 있었다. 본 연구는 에드워드 마이언(Edward D. Maryon)의 마르코톤의 음과 색의 이론을 바탕으로 뉴턴의 색채와 음계로 경상도 민요 밀양아리랑의 색채를 분석하였다. 분석 결과 밀양아리랑 음의 빈도에 의한 색채는 Blue Violet, Green Blue, Red, Yellow, Orange의 순으로 색채를 추출할 수 있었다. 추출된 색에서 연상되는 형용사 이미지는 힘, 정열, 인내, 열정, 진취적인, 우호적, 야망, 불꽃 등으로 경상도 지역 이미지로 연관 시킬 수 있다. 본 연구는 경상도민요 밀양아리랑의 음을 분석하여 색의 연상이미지와 지역 색을 찾는데 그 의의를 두었다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10b
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• pp.499-501
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• 2001

본 논문에서는 각 광원의 위치에 대해 미리 구한 라디안스 맵에 시간-색 공간에서의 반사요소 분리방법을 적용하여 난반사 라디안스 맵과 거울반사 라디안스 맵을 구한다. 필셀 BRDF를 얻기 위한 입력으로 반사요소가 분리된 라디안스 맵을 사용하였다. 따라서, 광원의 조작에 대해 난반사와 거울반사 이미지를 각각 제어할 수 있다. 시간-색 공간에서의 반사요소 분리방법을 사용함으로써, 이미지의 전역 정보가 아니라 지역 정보만을 이용한 반사요소 분리가 가능하다.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 1996.06a
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• pp.63-77
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• 1996

본 연구에서는 지리 정보 시스템(GIS: geographic information system)에서 주로 사용되는 공간 객체를 위한 색인 방법에 대해서 과거의 연구를 토대로 분류를 해보고 이로부터 새로이 제안하는 색인 방법인 MAX (Multi-Attribute indexing scheme)에 대해서 상세히 기술한다. 또한 MAX의 여러 연산을 위한 알고리즘을 제시하고, 알고리즘의 우수성을 제시한다. 이미 성능 평가를 통해 어느 정도의 성능을 기대할 수 있으며, 이를 실제 시스템에 구현한다면 상당한 성능을 가진 지리 정보 시스템을 구축할 수 있을 것이다. 특히 MAX는 이 기법이 가지는 B 트리의 확장성으로 쉽게 구현할 수 있는 구조를 가지게 된다.

• Spatial Information Research
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• v.6 no.2
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• pp.125-132
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• 1998

The I/O performance for spatial queries is extremely important since the handling of huge amount of multidimensional data is required in spatial databases for geographic information systems. Therefore, we describe representative spatial access methods handling complex spatial objects, z-transform B tree, KDB tree, R tree, MAX tree, to increase I/O performance. In addition, we measure the performance of spatial indexing schemes by testing against various realistic data and query sets. Results from the benchmark test indicates that MAX outperforms other indexing schemes on insertion, range query, spatial join. MAX tree is expected to use as index scheme organizing storage system of GIS in the future.