• Journal of KIISE:Databases
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• v.33 no.4
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• pp.396-408
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• 2006

Moving object databases manage a large amount of past location data which are accumulated as the time goes. To retrieve fast the past location of moving objects, we need index structures which consider features of moving objects. The KDB-tree has a good performance in processing range queries. Although we use the KDB-tree as an index structure for moving object databases, there has an over-split problem in the spatial domain since the feature of moving object databases is to increase the time domain. Because the over-split problem reduces spatial regions in the MBR of nodes inverse proportion to the number of splits, there has a problem that the cost for processing spatial-temporal range queries is increased. In this paper, we propose the dynamic split strategy of the KDB-tree to process efficiently the spatial-temporal range queries. The dynamic split strategy uses the space priority splitting method for choosing the split domain, the recent time splitting policy for splitting a point page to maximize the space utilization, and the last division policy for splitting a region page. We compare the performance of proposed dynamic split strategy with the 3DR-tree, the MV3R-tree, and the KDB-tree. In our performance study for range queries, the number of node access in the MKDB-tree is average 30% less than compared index structures.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.09a
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• pp.271-272
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• 2010

본 연구의 목적은 상황 인식 위치 기반 서비스를 위해 정성적인 개인 공간 행동을 포착하는 새로운 방법을 제안하는 것이다. 단순한 추적이내 사람의 위치 변화에 대해 색인 생성을 넘어서서, 사람과 환경 사이의 관계 변화가 본 연구의 공식 모텔에 대한 기본 소스로 간주된다. 특히 이 연구는 특정 지역의 경계 근처에서의 사람의 움직이는 행위에 중점을 둔다. 그 행위를 포착하기 위해 그 개체의 영향력 범위를 적용하는 새로운 접근 방법이 제안된다. 이러한 개체 시공간적으로 확장된 점는 그 영향력 범위를 그 개체의 위치와 함께 잠재적 사건이내 상호작용 구역으로 간주한다. 이렇게 포착된 정성적 공간 행위는 알려진 지역 근처의 개체 관계의 더 정제된 설명을 제공하여 단순한 공간정보 제공을 넘어선 실시간 공간 의사 결정 지원 시스템 강화에 도움을 줄 수 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.75-78
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• 2006

이 논문은 이동 차량의 궤적 정보 관리를 통한 물류 관리 시스템을 제안한다. 물류 시스템은 물류 센터에서 차량과 배송 물품의 위치를 지속적으로 모니터링하고, 이와 연관된 서비스를 제공하는 시스템이다. 따라서 물류 차량의 실시간 위치 정보관리가 필수적이다. 제안된 시스템은 기존의 지리 정보와 더불어 실세계 모바일 환경에서 물류 배송 정보의 효율적 관리 기능을 지원한다. 또한 효과적인 물류 이동 경로 관리 및 검색을 위하여 시공간 색인 기법을 적용하였다. 제안된 시스템은 물류 관리 뿐만 아니라 이와 유사한 서비스를 제공하는 차량 추적 시스템, 위치 기반 서비스 등과 같이 모바일 환경에서 실시간으로 변화하는 관리 대상 객체의 위치 정보를 관리하는 분야에 적용 가능하다.

• Journal of KIISE:Databases
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• v.32 no.1
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• pp.71-85
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• 2005

Various researches on moving object modeling, uncertainty processing, and moving object indexing have been tarried out in the field of moving object databases. However. previous location tracking systems cannot efficiently retrieve location data of vehicles, because they manage all location information of vehicles using the conventional database. In this paper, we design the vehicle location management systen that is able to manage and retrieve vehicle locations efficiently in mobile environment. The proposed system consists of a server for managing vehicle locations and mobile clients. The system is able to not only process spatiotemporal queries related to locations of moving vehicles but also Provide moving vehicles' locations which are not stored in the system. The system is also able to manage vehicle location data effectively using a moving object index.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.3
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• pp.13-21
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• 2011

In mobile environment supporting mobility technologies, user requirements have been increased with respect to utilization of location information. In particular, moving object DBMS has consistently posed in order to efficiently maintain traffic information related to location of vehicle which tents to tremendously change over time. Despite the fact that these sorts of researches must be taken into consideration, empirical studies on moving object in terms of map database for lbs service, spatial attribute of which is continuously changed over time, have rarely performed. Therefore, aim of this paper is to suggest efficient spatial index scheme, which is capable of supporting query processing algorithm and location of moving object over time, by developing new empirical model. As a result, we can come to the conclusion that moving object model based on multi-fixed grid index makes it possible to cut down on the number of entity for retrieving. What's more, this model enables hierarchical data to be accessed through efficient spatial filtering on large-scale lbs data and constraints in accordance with level in order to display map.

• The KIPS Transactions:PartD
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• v.14D no.5
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• pp.459-470
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• 2007

A data stream is a massive unbounded sequence of data elements continuously generated at a rapid rate. Query processing for such a data stream should also be continuous and rapid, which requires strict time and space constraints. In most DSMS(Data Stream Management System), the selection predicates of continuous queries are grouped or indexed to guarantee these constraints. This paper proposes a new scheme tailed an ASC(Attribute Selection Construct) that collectively evaluates selection predicates containing the same attribute in multiple continuous queries. An ASC contains valuable information, such as attribute usage status, partially pre calculated matching results and selectivity statistics for its multiple selection predicates. The processing order of those ASC's that are corresponding to the attributes of a base data stream can significantly influence the overall performance of multiple query evaluation. Consequently, a method of establishing an efficient evaluation order of multiple ASC's is also proposed. Finally, the performance of the proposed method is analyzed by a series of experiments to identify its various characteristics.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.469-478
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• 2010

This paper proposes the effective shape descriptor for 3D foot pose estimation. To reduce processing time, silhouette-based foot image database is built and meta information which involves the 3D pose of the foot is appended to the database. And we proposed a modified Centroid Contour Distance whose size of the feature space is small and performance of pose estimation is better than the others. In order to analyze performance of the descriptor, we evaluate time and spatial complexity with retrieval accuracy, and then compare with the previous methods. Experimental results show that the proposed descriptor is more effective than the previous methods on feature extraction time and pose estimation accuracy.

• Journal of the Korean Society for information Management
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• v.33 no.3
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• pp.155-176
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• 2016

This study aims to develope a scholarly metadata information system based on conceptual elements of text structure of Korean studies research articles and to identify the applicability of text structure based metadata as compared with the existing similar system. For the study, we constructed a database(Korean Studies Metadata Database, KMD) with text structure based on metadata of Korean Studies journal articles selected from the Korea Citation Index(KCI). Then we verified differences between KCI system and KMD system through search results using same keywords. As a result, KMD system shows the search results which meet the users' intention of searching more efficiently in comparison with the KCI system. In other words, even if keyword combinations and conditional expressions of searching execution are same, KMD system can directly present the content of research purposes, research data, and spatial-temporal contexts of research et cetera as search results through the search procedure.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.2
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• pp.30-41
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• 2006

This paper proposes an e-logistics system supporting efficient vehicle moving trajectory management. Recent advances in wireless communications have given rise to a number of location-based services including logistics vehicle tracking, cellular phone user's location finding, and location-based commerce. Logistics systems typically entail tracking vehicles for purposes of the logistics center knowing the whereabouts of the vehicles and/or consignments. Moreover, storing and managing location trajectory of continuously moving vehicles and consignments is necessary for supporting efficient logistics plan and consignment. The proposed system is able to manage spatial objects in GIS as well as logistic information in the mobile environment. And for the efficiently managing and retrieving of transporting trajectory of logistics, we extend previous moving object indexing method, TB-Tree, to use multi-version framework and evaluate data updating performance. It is able to apply the proposed method to develop mobile contents services based on continuously changing location of moving object in the mobile environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.578-581
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• 2007

For tracing tag locations, a trajectories should be modeled and indexed in radio frequency identification (RFID) systems. The trajectory of a tag can be represented as a line that connects two spatiotemporal locations captured when the tag enters and leaves the vicinity of a reader. If a tag enters but does not leave a reader, its trajectory is represented only as a point captured at entry. Because the information that the tag stays in the reader is missing from the trajectory represented only as a point, we should extend the region of a query to find the tag that remains in a reader. In this paper, we propose an interval data model of tag's trajectory in order to solve the problem. Trajectories of tags are represented as two kinds of intervals; dynamic intervals which are time-dependent lines and static intervals which are fixed lines. We also show that the interval data model has better performance than others with a cost model