• Journal of KIISE:Databases
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• v.31 no.5
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• pp.505-515
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• 2004

One of the most important issue in location-aware computing is tracking moving objects efficiently. To this end, an efficient protocol which updates location information in a location server is highly needed. In fact, the performance of a location update strategy highly depends on the assumed mobility pattern. In most existing works, however, the mobility issue has been disregarded and too simplified as linear function of time. In this paper, we propose a new mobility model, called state-based mobility model (SMM) to provide more generalized framework for both describing the mobility and updating location information of complexly moving objects. We also introduce the state-based location update protocol (SLUP) based on this mobility model. Using experimental comparison, we illustrate that the proposed technique is many times better in reducing location update cost and the communication bandwidth consumption.

• Journal of KIISE:Databases
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• v.33 no.1
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• pp.1-11
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• 2006

It is possible to track the moving vehicle as well as to develop the location based services actively according to the progress of wireless telecommunication and GPS, to the spread of network, and to the miniaturization of cellular phone. To provide these location based services, it is necessary for an index technique to store and search too much moving object data rapidly. However the existing indices require a lot of costs to insert the data because they store every position data into the index directly. To solve this problem in this paper, we propose a buffer node operation and design a GU-tree(Group Update tree). The proposed buffer node method reduces the input cost effectively since the operation stores the moving object location data in a group, the buffer node as the unit of a non-leaf node. hnd then we confirm the effect of the buffer node operation which reduces the insert cost and increase the search performance in a time slice query from the experiment to compare the operation with some existing indices. The proposed tufter node operation would be useful in the environment to update locations frequently such as a transportation vehicle management and a tour-guide system.

• Journal of Korea Multimedia Society
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• v.9 no.5
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• pp.529-541
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• 2006

In this paper, we propose a semi-automatic segmentation method which can be used to generate video object plane (VOP) for object based coding scheme and multimedia authoring environment. Semi-automatic segmentation can be considered as a user-assisted segmentation technique. A user can initially mark objects of interest around the object boundaries and then the selected objects are continuously separated from the un selected areas through time evolution in the image sequences. The proposed segmentation method consists of two processing steps: partially manual intra-frame segmentation and fully automatic inter-frame segmentation. The intra-frame segmentation incorporates user-assistance to define the meaningful complete visual object of interest to be segmentation and decides precise object boundary. The inter-frame segmentation involves boundary and region tracking to obtain temporal coherence of moving object based on the object boundary information of previous frame. The proposed method shows stable and efficient results that could be suitable for many digital video applications such as multimedia contents authoring, content based coding and indexing. Based on this result, we have developed objects based video editing system with several convenient editing functions.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.142-144
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• 2004

다양한 지리 관측 기술 및 GPS 그리고 무선통신 기술의 발달로 인해, 해수의 흐름 변화 관측이나 PDA를 장착한 물류 차량 관리와 같이 시간에 따라 이동하는 여러 객체들의 변화를 추적하고 관리하는 것이 용이해지고 있다. 그리고. 이로 인해 지능형 교통 시스템. 물류 차량 관리 시스템 등이 활발히 개발되고 있다. 그러나 개발된 시스템에서 차량 운송 계획 평가 및 테스트를 할 경우 차량의 실제 데이터가 부족하기 때문에 적절한 평가 및 다양한 테스트를 하기 힘들고, 실생활에 알맞은 시스템을 만들기 어려움 점이 있다. 이렇게 부족한 차량 데이터를 보충하기 위해, 대부분의 연구에서는 몇몇의 이동 객체 위치 데이터 생성기를 활용하고 있다. 그러나 기존의 이동 객체 데이터 생성기는 단순히 정규 분포, 가우스 분포. 랜덤 데이터. 도로 정보 등을 고려하여 데이터를 생성하기 때문에. 사용자가 물류 수송 계획 등에 활용하기 위해 의도한 시나리오에 따른 데이터를 생성하지 못하고 있다. 따라서, 이 논문에서는 차량 위치 데이터 생성기에 사용자가 지정한 시나리오를 생성, 저장하는 이동 객체 패턴 제공기를 추가하여. 사용자 지정 시나리오를 지원하는 차량 위치 데이터 생성기를 설계한다 이 논문에서 설계된 차랑 위치 데이터 생성기는 사용자가 원하는 계획대로 차량의 위치 정보를 생성함으로써, 물류 수송 및 도로 건설계획 등을 검토할 때 도움이 될 수 있을 것이다.

• Journal of Platform Technology
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• v.11 no.1
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• pp.52-59
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• 2023

The importance of spatio-temporal trajectories for contact tracing has increased due to the recent COVID-19 pandemic. Spatio-temporal trajectories store time and spatial data of moving objects. In this paper, I propose query processing for spatio-temporal trajectories of moving objects. The spatio-temporal trajectory model of moving objects has point type spatial data for storing locations and timestamp type temporal data for time. A trajectory query is a query to search for pairs of users who have been in close contact by boarding the same bus. To process the trajectory query, I use the Geolife dataset provided by Microsoft. The proposed trajectory query processing method divides trajectory data by date and checks whether users' trajectories were nearby for each date to generate information about contacts as the result.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10B
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• pp.1986-1994
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• 1999

In this paper, a semi-automatic approach is adopted to extract a semantic object from real-world video sequences human-aided segmentation for the first frame and automatic tracking for the remaining frames. The proposed algorithm has a hierarchical structure using watershed algorithm. Each hierarchy consists of 3 basic steps: First, seeds are extracted from the simplified current frame. Second, region growing bv a modified watershed algorithm is performed to get over-segmented regions. Finally, the segmented regions are classified into 3 categories, i.e., inside, outside or uncertain regions according to region probability values, which are acquired by the probability map calculated from an estimated motion-vector field. Then, for the remaining uncertain regions, the above 3 steps are repeated at lower hierarchies with less simplified frames until every region is classified into a certain region. The proposed algorithm provides prospective results in studio-quality sequences such as 'Claire', 'Miss America', 'Akiyo', and 'Mother and daughter'.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.18 no.2
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• pp.16-22
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• 2010

This paper proposes the real-time moving object tracking system UAV using color information. Case of object tracking, it have studied to recognizing the moving object or moving multiple objects on the fixed camera. And it has recognized the object in the complex background environment. But, this paper implements the moving object tracking system using the pan/tilt function of the camera after the object's region extraction. To do this tracking system, firstly, it detects the moving object of RGB/HSI color model and obtains the object coordination in acquired image using the compact boundary box. Secondly, the camera origin coordination aligns to object's top&left coordination in compact boundary box. And it tracks the moving object using the pan/tilt function of camera. It is implemented by the Labview 8.6 and NI Vision Builder AI of National Instrument co. It shows the good performance of camera trace in laboratory environment.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1384-1387
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• 2010

최근 무선인터넷의 기술을 이용한 스마트폰의 활용도가 높아짐에 따라 새로운 서비스의 연구분야로 단말기를 이용하여 이동객체의 위치정보를 제공받는 위치 기반 서비스 기술에 관심이 높아지고 있다. 하지만 현재 기술은 GPS를 이용한 위치추적으로 외부의 이동객체를 추적하는 기술로 많이 활용되고 있다. 그리고 고정된 레퍼런스 노드 또는 마스터 노드에 의존하고 있는 문제점과 위치 계산을 위한 기준이 대부분 홉스나 RF신호의 수신강도에 의한 거리차를 이용하는데 전파 특성에 따른 회절 및 반사, 다중 경로 등에 의한 신호감쇠현상으로 정확도를 보장하지 못하는 문제점이 있다. 따라서 본 논문에서는 GPS와 WiFi를 이용하여 고정된 레퍼런스 노드에 의존하지 않고 이동식 GPS-AP를 이용하여 건물내부에 위치하는 특정 단말기의 위치정보를 제공할 수 있는 시스템을 제안한다.

• Journal of the Korea Society of Computer and Information
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• v.11 no.1 s.39
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• pp.87-96
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• 2006

Selectivity estimation is one of the query optimization techniques. It is difficult for the previous selectivity estimation techniques for moving objects to apply the position change of moving objects to synopsis. Therefore, they result in much error when estimating selectivity for queries, because they are based on the extended spatial synopsis which does not consider the property of the moving objects. In order to reduce the estimation error, the existing techniques should often rebuild the synopsis. Consequently problem occurs, that is, the whole database should be read frequently. In this paper, we proposed a moving object histogram method based on quad tree to develop a selectivity estimation technique for moving object queries. We then analyzed the performance of the proposed method through the implementation and evaluation of the proposed method. Our method can be used in various location management systems such as vehicle location tracking systems, location based services, telematics services, emergency rescue service, etc in which the location information of moving objects changes over time.

• Journal of Korea Spatial Information System Society
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• v.10 no.3
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• pp.67-78
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• 2008

With the rapid development of wireless communication and mobile equipment, many applications for location-based services have been emerging. Moving objects such as vehicles and ships change their positions over time. Moving objects have their moving path, called the trajectory, because they move continuously. To monitor the trajectory of moving objects in a large scale database system, an efficient Indexing scheme to processed queries related to trajectories is required. In this paper, we focus on the issues of minimizing the dead space of index structures. The Minimum Bounding Boxes (MBBs) of non-leaf nodes in trajectory-preserving indexing schemes have large amounts of dead space since trajectory preservation is achieved at the sacrifice of the spatial locality of trajectories. In this thesis, we propose entry relocating techniques to reduce dead space and overlaps in non-leaf nodes. we present performance studies that compare the proposed index schemes with the TB-tree and the R*-tree under a varying set of spatio-temporal queries.