• 한국공간정보시스템학회:학술대회논문집
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• 2004.12a
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• pp.91-97
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• 2004

GPS 및 무선 통신 기술의 발달과 무선기기의 소형화, 고속 네트워크 구축 등에 힘입어 휴대전화 사용 고객이나 차량의 위치 추적이 용이해지고 있다. 이로 인해 차량 및 고객이 변화하는 위치에 따라 적절한 서비스를 제공하는 위치 기반 서비스가 활발히 연구되고 있으며, 원활한 교통 소통 및 물류 수송을 위해 차량의 위치 정보를 적절히 활용, 관리하는 차량 추적 및 관리 시스템이 개발되고 있다. 그러나 개발된 차량 관리 시스템들은 각 시스템마다 서로 다른 차량 위치 데이터 저장 구조 및 질의 처리 방식과 색인 기법 등을 활용하기 때문에, 시스템간의 호환 및 정보 교환 등에 어려움을 갖고 있다. 따라서 이 논문에서는 차량 관리 시스템간의 정보 교환 및 차량의 위치 및 궤적 데이터의 효과적인 질의를 지원하기 위한 이동 객체질의어를 설계하고, 이를 지원하는 차량 관리 시스템을 구현한다. 제시된 이동 객체 질의어는 SQL를 기반으로 물류 관리 시스템에서 특정 구간 사이의 궤적, 특정 지점에서의 출발 렌 도착 시간 및 불확실한 위치 추정 등과 같은 차량의 이동에 대한 정보를 얻기 위해 지원된다. 그리고, 물류 차량 관리를 포함한 다양한 이동 객체 관리 시스템에서 이러한 이동 객체 질의어와 같은 어떤 표준화된 질의어를 지원할 경우, 서로 간의 정보 활용에 많은 도움을 줄 수 있다.

• 한국공간정보시스템학회:학술대회논문집
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• 2003.11a
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• pp.123-128
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• 2003

최근 프로세서와 메인 메모리간의 속도 차이가 커지면서 캐시 실패가 메인 메모리에서 동작하는 R-Tree의 성능 저하에 미치는 영향이 커짐에 따라 캐시 실패를 줄여 캐시 성능을 개선하려는 연구가 많이 진행되고 있다. 일반적인 캐시 성능 개선 방법은 엔트리 정보를 줄설 노드에 더 않은 엔트리를 저장함으로써 펜-아웃(fanout)을 증가시키고 캐시 실패를 최소화한다. 그러나 이러한 방법은 엔트리 정보를 줄이는 추가 연산으로 인해 갱신 성능이 떨어지고, 노드간 이동시 발생하는 캐시 실패는 여전히 해결하지 못하고 있다. 본 논문은 이를 해결하기 위해 선반입(prefetching)을 적용한 확장된 R-Tree인 PR-tree(Prefetching R-Tree)를 제안하고 평가하였다 PR-Tree는 펜-아웃을 증가시키고 트리의 높이를 낮추기 위해 실제 캐시 라인의 정수 배인 노드를 생성하고, 선반입을 적용하여 노드 캐시로 인한 메모리 지연을 최소화하였다. 또한 접근할 노드를 선반입하여 노드간 이동시 발생하는 캐시 실패도 최소화하였다. PR-Tree는 실험에서 R-Tree보다 검색 연산에서 최대 38%의 성능 향상을 보였으며, 갱신 연산에서도 최대 30%의 성능 향상을 보였다.

• Journal of Korea Spatial Information System Society
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• v.10 no.1
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• pp.29-40
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• 2008

With the spread of mobile devices and advances in communication techknowledges, the needs of application which uses the movement patterns of moving objects in history trajectory data of moving objects gets Increasing. Especially, to design public transportation route or road network of the new city, we can use the similar patterns in the trajectories of moving objects that move on the spatial network such as road and railway. In this paper, we propose a spatio-temporal similar trajectory search algorithm for moving objects on road network. For this, we define a spatio-temporal similarity measure based on the real road network distance and propose a grid-based index structure for similar trajectory search. Finally, we analyze the performance of the proposed similar trajectory search algorithm in order to show its efficiency.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.868-876
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• 1999

In this paper, an efficient automatic video parsing technique on MPEG-compressed video that is fundamental for content-based indexing is described. The proposed method detects scene changes, regardless of IPB picture composition. To detect abrupt changes, the difference measure based on the dc coefficient in I picture and the macroblock reference feature in P and B pictures are utilized. For gradual scene changes, we use the macroblock reference information in P and B pictures. the process of scene change detection can be efficiently handled by extracting necessary data without full decoding of MPEG sequence. The performance of the proposed algorithm is analyzed based on precision and recall. the experimental results verified the effectiveness of the method for detecting scene changes of various MPEG sequences.

• The Transactions of the Korea Information Processing Society
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• v.7 no.11
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• pp.3333-3340
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• 2000

Recently, Requnremeni for video data have been increased rapidly by high progress of both hardware and cornpression technique. Because digital video data are unformed and mass capacity, it needs various retrieval techniquesjust as contednt-based rehieval Superimposed-caption ina digital video can help us to analyze the video story easier and be used as indexing information for many retrieval techniques In this research we propose a new method that segments the caption as analyzing texture eature of caption regions in each video frame, and that extracts the accurate scope of superimposed-caption frame and its key regions and color by measunng cominuity of caption regions between frames

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.38 no.1
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• pp.46-57
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• 2001

To access the multimedia data, such as video data with temporal properties, the content-based image retrieval technique is required. Moreover, one of the basic techniques for content-based image retrieval is an extraction of representative key-frames. Not only did we implement this method, but also by analyzing the video data, we have proven the proposed method to be both effective and accurate. In addition, this method is expected to solve the real world problem of building video databases, as it is very useful in building an index.

• Spatial Information Research
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• v.1 no.1
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• pp.7-16
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• 1993

Current computer technologies developing. our requirements are changing from simple alpha-numeric processing to graphic and image. spatial data processing which are easy for user to understand and use. Geographic information system is a kind of spatial database system that can not only print out the data in the form of maps but also manipulate. store. retrieve. and analyze the geographic data. It is efficient system that can process the spatial data which has a geographical feature and its relative attribute data. Conventional relational database management systems are not suitable for spatial data processing, so we need to design the spatial database mana-gement system which is suitable for efficient spatial data processing. In this paper we design the extended storage management system that supports the spatial index technique that allows user to access fast and store and manage the enormous spatial data efficiently like geographic information system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.8B
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• pp.929-938
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• 2011

The setting algorithm of cloaking region using dummy which is proposed in this paper solves the problem which counts the building with duplication that exists in several cells of Privacy Grid by adding the building grouping item to the index structure of the existing Privacy Grid, and by increasing K value after searching the contiguous cells in the comer of each building, the exposure problem of private location information due to the minimum cloaking region setting of the existing GBC is solved. In addition, this paper reduces the searching time of K value by setting smaller cloaking region than Privacy Grid and GBC with dummy K before expanding cloaking region and strengthens the location information protection of users using dummy K.

• The KIPS Transactions:PartB
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• v.12B no.7 s.103
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• pp.761-766
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• 2005

This paper proposes a video model for the implementation of the cultural video database system. We have utilized an efficient scene change detection method that segments cultural video into semantic units for efficient indexing and retrieval of video. Since video has a large volume and needs to be played for a longer time, it implies difficulty of viewing the entire video. To solve this Problem. the cultural video abstraction was made to save the time and widen the choices of video the video abstract is the summarization of scenes, which includes important events produced by setting up the abstraction rule.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.9
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• pp.1584-1590
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• 2008

The combined query which consists of the region and trajectory query finds trajectories of moving objects which locate in a certain region. The trajectory query is very informant factor to determine query performance because it processes a point query continuously to find predecessors. This results in bad performance due to revisiting nodes in an index. This paper suggests an efficient method for the combined query based on the 3-dimensional R-tree which has good performance of the region query. The basic idea is that we define the least common search line which enables to search single path and a filtering method based on prediction without revisiting nodes.