• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.893-898
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• 2002

Integration with CORBA and mobile agent is improving various kinds problems that are happening in distributed system. This technology is guarantee the interoperability to other agent platforms and extend the mobile agent system but appears various kinds problems of suity. In this paper, we propose the mobile agent security system that is based on CORBA security service specification and MASIF. Since Proposed system is based on CORBA and MASIF, it is extend the large scale of distributed system and interoperable with other agent platforms.

• 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.

• 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.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.04a
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• pp.225-231
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• 2003

최근 모바일 장치의 발전으로 인하여 이동 객체의 위치를 기반으로 하는 위치 기반 서비스(LBS:Location Based Service)가 발전되고 있다. 위치 기반 서비스에서는 이동객체의 위치 정보가 시간의 흐름에 따라 그 변화량이 방대하게 증가되기 때문에 대용량 데이터를 관리하기 위한 데이터베이스의 필요성이 요구되고 있다. 기존의 데이터베이스 시스템은 하나의 서버가 모든 처리를 담당하므로 동시 사용자 수가 제한되고, 사용자의 수가 증가할수록 성능이 저하된다. 특히, 사용자 질의의 급증에 대해 유연하게 대처하지 못해 시스템이 정지하여 서비스를 제공하지 못하게 된다. 본 논문에서는 대량의 데이터를 관리하고, 사용자 질의가 급증하여도 서비스가 계속되는 GMS/Cluster를 제안한다. 제안한 GMS/Cluster는 비공유 데이터베이스 클러스터로 독립적으로 질의를 처리할 수 있는 노드와 노드들의 묶음인 그룹으로 구성된다. GMS/Cluster는 분할 정책의 사용으로 대량의 데이터를 효율적으로 관리하여 성능이 향상되고, 복제 정책의 사용으로 서비스를 하던 노드가 정지되어도 복제본을 가진 노드가 대신 서비스를 하여 가용성이 높아지며, 서비스를 중지하지 않고 실시간으로 온라인 확장을 하여 급증하거나 접근 패턴이 변경하는 사용자 질의에 대처할 수 있다.

• Journal of KIISE:Databases
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• v.31 no.5
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• pp.492-504
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• 2004

Recently, as growing of interest for LBS(location-based services) techniques, lots of works on moving objects that continuously change their information over time, have been performed briskly. Also, researches for NN(nearest neighbor) query which has often been used in LBS, are progressed variously However, the results of conventional NN Query processing techniques may be invalidated as the query and data objects move. Therefore, they are usually meaningless in moving object management system such as LBS. To solve these problems, in this paper we propose a new nearest neighbor query processing technique, called CTNN, which is possible to meet accurate and continuous query processing for moving objects. Our techniques include an Approximate CTNN(ACTNN) technique, which has quick response time, and an Exact CTNN(ECTNN) technique, which makes it possible to search nearest neighbor objects accurately. In order to evaluate the proposed techniques, we experimented with various datasets. Experimental results showed that the ECTNN technique has high accuracy, but has a little low performance for response time. Also the ACTNN technique has low accuracy comparing with the ECTNN, but has quick response time The proposed techniques can be applied to navigation system, traffic control system, distribution information system, etc., and specially are most suitable when both data and query are moving objects and when we already know their trajectory.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.6
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• pp.555-568
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• 2000

The World Wide Web has become the largest virtual system that is almost universal in scope. In recent research, it has become effective to utilize idle hosts existing in the World Wide Web for running applications that require a substantial amount of computation. This novel computing paradigm has been referred to as the advent of global computing. In this paper, we implement and propose a mobile object-based global computing framework called Tiger, whose primary goal is to present novel object-oriented programming libraries that support distribution, dispatching, migration of objects and concurrency among computational activities. The programming libraries provide programmers with access, location and migration transparency for distributed and mobile objects. Tiger's second goal is to provide a system supporting requisites for a global computing environment - scalability, resource and location management. The Tiger system and the programming libraries provided allow a programmer to easily develop an objectoriented parallel and distributed application using globally extended computing resources. We also present the improvement in performance gained by conducting the experiment with highly intensive computations such as parallel fractal image processing and genetic-neuro-fuzzy algorithms.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.376-378
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• 2004

최근에 지리 정보를 검색, 관리, 분석 할 수 있는 지리 정보 시스템(Geographic Information System, CIS)의 사용이 확대됨에 따라 단순한 수치지도 정보 이외에 좀 더 현실적이고, 사실적인 정보를 제공해 줄 수 있는 시스템에 대한 요구가 커지고 있으며 이동통신 기술의 발달과 모바일 단말의 급속한 확산으로 인하여 지리 정보 시스템의 모바일 시스템화가 급속히 진행중이다. 이러한 현상에 맞추어 무선 인터넷 환경에서 공간 객체의 실제 영상 정보를 보여주는 시스템의 필요성이 대두되고 있다. 현장에서 공간 객체에 대한 영상 정보를 검색 할 수 있는 시스템은 현실적 모습 및 상태에 대한 정보를 실시간으로 제공해 줄 수 있어. 공간 객체의 실제 모습이 필요한 여러 분석이나 의사결정이 필요한 분야에서 효율적으로 이용될 수 있다. 공간 객체의 실제 영상 정보를 제공하기 위해 현재 영상을 고려하는 지리 정보 시스템이 개발 중이기는 하나, 이러한 시스템들은 무선 인터넷 환경을 고려하지 않고 있어, 현장에서 공간 객체에 대한 영상을 효율적으로 얻기에는 적합하지 않다. 본 논문에서는 무선 인터넷 환경에서의 공간 객체에 대한 영상 정보 검색 시스템을 설계하고 구현한다. 이를 위 해 1) 수치 지도 및 영상, 그리고 그 매핑 정보의 구축 방안을 제시한다. 그리고, 2) 제안된 시스템을 전체적으로 설계 및 구현함으로써, 그 유용성을 보인다.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.55-58
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• 2006

최근의 위치 측위 기술과 무선 통신 기술의 발전에 따라 위치 기반 서비스에 대한 관심이 크게 증가하고 있다. 휴대폰 사용자와 같은 대용량의 객체를 처리하기 위해서 기존의 단일 노드 기반 시스템으로는 어려움이 있어, 클러스터 기반 분산 컴퓨팅 구조로 GALIS 아키텍처가 제안되었다. 본 논문에서 제안하는 실시간 모니터링 시스템은 클러스터 기반 분산 컴퓨팅 구조로 제안된 GALIS 구현에 있어 기존 명령어 인터페이스를 GUI 로 개선하여 질의 처리 과정에 대한 직관성을 높이고, 각 노드의 부하를 모니터링 함으로써 각 노드의 역할을 동적으로 조정할 수 있게 각 노드별 이동 객체 처리 상황을 관리한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5873-5877
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• 2011

In this paper, we propose a study of analysis to the mobility of object such like pedestrian in safety management zone. If unusual situation is detected in safety management zone, it's designed that previous agreed mission will be processed. By human resource, safety management zone cannot be detected continuously so that through the induction of such detection system the reliability of area can be obtained. Hence, in this paper we propose the reaction scheme to detect special situation by object detection. By using sensor based processing system proposed by this paper, the detection of mobility and unusual situation can be implemented.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.2
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• pp.85-90
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• 2017

Various mobile devices are spreading in recent developments in mobile computing environments. Especially the popularity of mobile devices equipped with GPS has become widespread, and various application services utilizing location information are born. In this paper, we propose a system model for storing and managing the trajectory of moving objects, which is the set of location information of moving objects acquired in continuous time, and the UDF (User-Defined Functions) based trajectory index method which can quickly query the large data set of moving object and the Pre-Materialized table method. Then we compare and evaluate the performance of each method through experiments. Experimental results show that the Pre-Materialized table method is about 1.2 times faster than the UDF based trajectory index method on execution time.