• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.460-464
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• 2003

The objects which continuously change their locations in the real world are called moving objects. The works on the existing spatial indices have been proposed the retrieval methods. However, keeping track of the terminal location of moving objects is more important than the efficiency of the query processing in the moving object database. Therefore, many pure spatial indices are not applicable to the moving objects database which should maintain the object's current location as precise as possible. This parer proposes a method for reducing the construction time of indexing moving objects. We analyze the characteristics of the method to re-index all the objects after each time period and the method to update immediately the locations on reporting their locations. We also newly propose a selective immediate update method using the properties of moving objects in order to minimize the number of database updates.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.6
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• pp.1276-1282
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• 2003

The works on the existing spatial indices have been proposed the retrieval methods. However, keeping track of the terminal location of moving objects is more important than the efficiency of the query processing in the moving object database. Therefore, many pure spatial indices are not applicable to the moving objects database which should maintain the object's current location as precise as possible. This paper proposes a method for reducing the construction time of indexing moving objects. We analyze the characteristics of the method to re-index all the objects after each time period and the method to update immediately the locations on reporting their locations. We also newly propose a selective immediate update method using the properties of moving objects in order to minimize the number of database updates.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.345-349
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• 2004

In order to index exactly moving objects(vehicle, mobile phone, PDA, etc.) in the mobile database, continuous updates of their locations are inevitable as well as time-consuming. The studies of pure spatial indices have focused on the efficient retrievals. However, the acquisition and management of the terminal Location of moving objects are more important than the efficiency of the query processing in the moving object databases. Therefore, it will be need to adopt parallel processing system for the moving object databases which should maintain the object's current location as precise as possible. This paper proposes a architecture of spatial indexing mobile objects using multiple processors. More precisely, we newly propose a method of splitting buckets using the properties of moving objects in order to minimize the number of database updates. We also propose a acquisition method for gathering the location information of moving objects and passing the information of the bucket extents in order to reduce the amount of passed messages between processors.

• 한국공간정보시스템학회:학술대회논문집
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• 2003.11a
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• pp.135-140
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• 2003

차량과 같이 시간의 흐름에 따라 위치를 변경하는 객체를 이동체라 한다. 이동체의 과거 궤적은 시간이 지남에 따라 누적되므로 대용량 정보가 된다. 대용량 궤적 정보를 저장하는 이동체 데이터베이스에서 효율적으로 궤적을 검색하기 위해서는 색인이 필요하다. 특히 궤적을 선택하는 과정과 선택된 궤적의 일부분을 추출하는 과정으로 이루어진 복합 질의를 처리하기 위해서는 궤적 보존을 지원하는 TB-tree와 같은 색인 구조가 적합하다. 그러나 TB-tree와 같이 시간적으로 잘 구성된 색인은 공간적인 겹침이 괴지는 문제가 있고, 반대로 공간적으로 잘 구성된 색인은 시간 도메인의 겹침을 심화시키는 문제점이 있다. 이 논문에서는 시간 도메인 중심의 분할 정책과 공간 도메인 중심의 분할 정책을 분석하여 서로 다른 두 도메인 사이의 관계를 밝힐 수 있는 파라미터를 제안하고, 이를 TB-tree에 적용하여 78-tree의 장점을 유지하면서 영역 질의껜 효과적인 분할 정책을 설계 및 구현한다. 또한 성능평가를 통하여 제안된 분할 정책이 기존의 TB-tree 보다 영역 질의에서 우수함을 보인다.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2006.05a
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• pp.78-83
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• 2006

선택율 추정은 질의 최적화를 위한 기법중의 하나이다. 이동객체에 대한 기존 선택율 추정 기법은 시간에 따른 빈번한 이동객체의 위치 변화를 요약 정보에 반영하지 못함으로써 선택 율 추정시 많은 에러를 발생시키고 있다. 따라서 이 논문에서는 이동객체의 질의에 대한 선택율 추정을 위한 색인 기반의 히스토그램 기법을 제안하였다. 또한 제안된 기법의 구현과 평가를 통 해 제안된 기법의 성능을 분석하였다. 이 논문에서 제안된 기법은 차량 추적 시스템, 위치 기반 서비스, 응급 구조 서비스, 그리고 텔레매틱스 서비스 통과 같은 연속적으로 위치를 변경하는 이동객체의 정보를 실시간으로 관리하고 검색하는 응용분야에 활용 가능할 것이다.

• Journal of the Korea Computer Graphics Society
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• v.18 no.4
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• pp.9-15
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• 2012

Color harmony is affected by order of colors or orderly arrangement as well as harmonious colors themselves. In this paper, we show people perceive the degree of harmony differently according to the orderly arrangement of colors. Especially, we use the order of colors in color themes, or color schemes which have been largely used for color selection. We first present the method for harmony calculation of Ou's researches[1][2] and then suggest a method considering minimum color distance of component colors. For a design consisting of multiple colors, we show overall harmony of colors is more important than each harmony of adjacent component colors. By user study, we conclude that the suggested method can enhance the harmony of color theme.

• Journal of Korea Spatial Information System Society
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• v.7 no.1 s.13
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• pp.13-24
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• 2005

Objects, which change their positions over time such as cars, are called moving objects. Trajectories of a moving object have large volumes because trajectories are accumulated. Efficient indexing techniques for searching these large volumes of trajectories are needed in the moving object databases. Especially the TB-tree which supports bundling trajectories is suitable for processing combined queries which have 2 steps: first step is selecting trajectories (range search), next is selecting the parts of each trajectory (trajectory search). But the TB-tree has unnecessary disk accesses cause of lack of spatial discrimination in range queries. In this paper, we propose and implement the splitting polity which can reduce dead spaces of non-leaf node in order to process range queries efficiently. The policy has better performance about range queries than the TB-tree as well as the advantages of the TB-tree, such as highly space utilization and efficient trajectory extraction. This paper shows that the newly proposed split policy has better performance in processing the range queries than that of the TB-tree by experimental evaluation.

• Korean Journal of Optics and Photonics
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• v.29 no.1
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• pp.13-18
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• 2018

In this study, we present a symmetry graphical method to design an achromatic optical system composed of many lenses on an achromatic glass map. To take into account the lens spacing and the number of lenses, we use the relative ratio of paraxial ray height at each lens and the concept of an equivalent single lens. Converting an arbitrary optical system into various doublet systems, the most effective doublet is then selected to correct the color aberration, through material selection and the redistribution of the optical power. By designing a fisheye lens using this approach, an achromatic optical system is effectively obtained over the visible waveband.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.100-105
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• 2008

EPCglobal은 기업 간의 물류 활동 촉진과 글로벌 유통물류 시스템 구축을 위하여 EPCglobal Architecture Framework을 제시 하였다. EPCglobal Architecture Framework의 한 구성 요소인 EPCIS(Electronic Product Code Information Services)는 EPC, 시간, 위치와 같은 물류 관련 정보에 대해 저장 및 검색 서비스를 제공한다. EPCIS는 단발성 질의(poll)와 연속 질의(subscribe) 검색 서비스를 제공한다. EPCIS의 연속 질의는 시스템 자동화 및 재고 관리, 공급망 관리를 위해 다양한 응용에서 활용이 가능하다. 일반적으로 연속 질의 처리를 위해서는 등록된 연속 질의와 입력된 데이터를 순차적으로 비교하는 Sequential Matching 기법을 사용한다. Sequential Matching기법은 등록된 연속 질의 수가 증가 할 경우 많은 부하를 발생 시키고, 이로 인해 시스템 처리 지연이 발생한다. 본 논문에서는 EPCIS의 시공간 EPC 데이터의 연속질의 처리 성능 향상을 위해 선택률 기반 효율적인 연속질의 처리 기법을 제안한다. 13차원의 도메인을 여러 개의 질의 색인으로 구성하고, 등록된 질의 정보를 기반으로 선택률을 계산한다. 선택률에 의해 변경되는 동적 질의 실행 계획을 제안함으로써, EPCIS에서 시공간 EPC 데이터의 연속질의 처리에 대해 평균 60%의 성능이 향상이 가능하도록 하였다.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.5
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• pp.213-222
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• 2008

This paper is related to color image segmentation and textile texture mapping for the 2D virtual wearing system. The proposed system is characterized as virtually wearing a new textile pattern selected by user to the clothing shape section, based on its intensity difference map, segmented from a 2D clothes model image using color image segmentation technique. Regardless of color or intensity of model clothes, the proposed system is possible to virtually change the textile pattern or color with holding the illumination and shading properties of the selected clothing shape section, and also to quickly and easily simulate, compare, and select multiple textile pattern combinations for individual styles or entire outfits. The proposed system can provide higher practicality and easy-to-use interface, as it makes real-time processing possible in various digital environment, and creates comparatively natural and realistic virtual wearing styles, and also makes semi-automatic processing possible to reduce the manual works to a minimum. According to the proposed system, it can motivate the creative activity of the designers with simulation results on the effect of textile pattern design on the appearance of clothes without manufacturing physical clothes and, as it can help the purchasers for decision-making with them, promote B2B or B2C e-commerce.