• Journal of the Korea Society of Computer and Information
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• v.26 no.6
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• pp.29-35
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• 2021

In this paper, we propose a method that combines KNN(K-Nearest Neighbor), Local Map Classification and Bayes Filter as a way to increase the accuracy of location positioning. First, in this technique, Local Map Classification divides the actual map into several clusters, and then classifies the clusters by KNN. And posterior probability is calculated through the probability of each cluster acquired by Bayes Filter. With this posterior probability, the cluster where the robot is located is searched. For performance evaluation, the results of location positioning obtained by applying KNN, Local Map Classification, and Bayes Filter were analyzed. As a result of the analysis, it was confirmed that even if the RSSI signal changes, the location information is fixed to one cluster, and the accuracy of location positioning increases.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.12
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• pp.2663-2669
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• 2010

During the past 5 years, domestic VoIP service has grown rapidly absorbing more than 8 million subscribers. More recently, the increase of enterprise or institutional subscribers become more dominant than individual subscribers. Supporting emergency services such as 119 in these scaled up VoIP services is very essential. In current domestic VoIP networks, the VoIP terminal's location information which are provided to the PSAP with the arriving emergency call depends on the information which are entered at the subscription time or updated by the subscribers when the terminal is moved to other place. This manual provision of location information which requires the user's intervention can result in serious failure in saving people in emergency situations, in case that users are negligent in entering the information or users enter the wrong information. In this paper, we propose an enhanced mechanism in which the terminal's location information is automatically offered by the network for emergency services in ethernet-based enterprise VoIP networks.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.05a
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• pp.149-154
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• 2005

이동통신기술의 발달과 급속한 보급으로 인하여 모바일 서비스가 일반화되고 있으며, 모바일 서비스의 기본 인프라로 작용하고 있는 공간 위치정보(location information)의 중요성이 대두되고 있다. 2/3세대 이동통신망의 구조 및 통신 프로토콜에 대한 기술규격을 제공하고 있는 3GPP/3GPP2에서도 이동통신망에서 위치정보를 제공하기 위한 요소들과 이들 간의 인터페이스를 제공하고 있다. 특히 최근에는 사용자 레벨의 모바일 서비스간 상호운용성 제공을 목적으로 활발한 활동이 전개되고 있는 OMA(Open Mobile Alliance)의 LOCation Working Group에서 위치정보와 관련된 기술규격이 제정 중이다. 본 고에서는 3GPP/3GPP2와 OMA두 사실 표준기구의 활동을 중심으로 공간 위치정보 기술에 대한 기술 및 국제표준화 동향과 TTA를 통하여 진행되고 있는 국내 표준화 동향을 분석하고, 국내에 적용하기 위한 방안 등에 대하여 서술한다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.226-228
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• 2003

최근에 무선 인터넷과 이동 컴퓨팅 기술이 발전하고, 휴대 전화와 PDA 같은 이동 단말기가 보편화됨에 따라 사용자의 위치정보를 활용한 위치 기반 서비스(LBS: Location Based Services)가 가능하게 되었다. 위치 기반 서비스를 제공하기 위해서는 대용량의 위치 데이타를 신속하게 처리하고 관리하기 위한 시스템이 필요하다. 이에 본 논문에서는 위치 데이타를 효과적으로 분산 저장 및 검색할 수 있는 이동 객체를 위한 분산 위치 저장 컴포넌트를 구현하고 그 성능을 평가하였다. 분산 위치 저장 컴포넌트는 위치 데이타를 저장하고 검색하는 미들웨어, 분산된 미들웨어의 정보를 관리하는 서버 관리자, 빠른 검색을 위해 위치 데이타의 인덱스 정보를 관리하며 검색할 서버의 정보를 반환하는 연결 관리자, 서버의 디스크 상태를 확인하고 디스크 사용을 관리하는 디스크 관리자, 그리고 클라이언트로 구성된다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1779-1788
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• 2012

Recently, demands of application services in consideration of interior environment according to the stream of times, Ubiquitous. In case of interior location-based service, WLAN is now mostly used. But it is largely affected by environmental changes. To solve this problem, lots of studies on UWB are underway. The reason why studies on UWB are much made lies in that it is not much affected by environment changes owing to radio wave characteristics. So this study suggests the location correction algorithm which derives values with less influence of environment and high accuracy and corrects with more accurate location information using Ubisense system based on UWB technologies. The location correction algorithm suggested is one made after constructing environment database and use it to estimate more accurate location from the location measuring system in a high position.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.508-511
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• 2005

In the near future various new services will be created by using ubiquitous computing and ubiquitous network. Especially u-LBS(Ubiquitous Location Based Services) is recognized as one of the most important services. U-LBS is based on the data created by recognizing objects including both human and matters at any time and anywhere. Many researches related with object locating method by using RF are in the process of studying However there are few researches on the location of objects. In this paper we propose the recognition method of the location of objects by using RF and USN technology. In detail, the strength of RF signal is used to recognize the location of objects. Also we discuss about the future work to enhance the recognition rate of location by using a number of conditions including the weather, temperature etc. And Genetic Algorithm is used to get the optimal parameters with which we can get the more exact recognition rate of location.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.1
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• pp.50-56
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• 2014

Recently Android apps utilizing location based services are widely used. Understanding the operation of the GPS location provider, among various location providers supported in the Android platform, is an essential task for developers using the Android. This paper, based on the analysis of source codes of the GPS subsystem in the Android platform, shows clearly and orderly the operation of the GPS location provider, in key threads' perspectives as well as in a stepwise fashion from the initialization up to the final location report steps.

• Journal of Information Technology Services
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• v.10 no.4
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• pp.243-258
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• 2011

With increasing interest in ubiquitous computing technology, an infrastructure for the short-distance wireless communication has been extended socially, bringing spotlight to the security system using the image or location. In case of existing security system, there have been issues such as the occurrences of blind spots, difficulty in recognizing multiple objects and storing of the unspecified objects. In order to solve this issue, zone-based location-estimation search system for the image have been suggested as an alternative based on the real-time location determination technology combined with image. This paper intends to suggest the search service for the image zone-based location-estimation. For this, it proposed the location determination algorism using IEEE 802.15.4/ZigBee's RSSI and for real-time image service, the RTP/RTCP protocol was applied. In order to combine the location and image, at the event of the entry of the specified target, the record of the time for image and the time of occurrence of the event on a global time standard, it has devised a time stamp, applying XML based meta data formation method based on the media's feature data based in connection with the location based data for the events of the object. Using the proposed meta data, the service mode which can search for the image from the point in time when the entry of the specified target was proposed.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.81-84
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• 2005

Various design schemes for network using wireless sensor nodes have been widely studied on the several application areas ranging from the real world information collection to environmental monitor. Currently, the schemes are focused on the design of sensor network for low power consumption, power-aware routing protocol, micro miniature operating system and sensor network middleware. The indoor localization system that identifies the location of the distributed nodes in a wireless sensor network requires features dealing with mobility, plurality and other environmental constraints of a sensor node. In this paper, we present an efficient location system to cope with mobility of multiple mobile nodes by designing a location handler that processes location information selectively depending on the nodes' density in a specific region. In order to resolve plurality of multiple mobile nodes, a routing method for the location system is also proposed to avoid the occurrence of overlapped location data.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.329-334
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• 2010

Due to the advancement of mobile wireless networks, various LBS's (Location Based Service) with the knowledge of mobile station's current position are emerging. Providing LBS is very essential feature in Mobile WiMAX networks such as WiBro networks for their competitiveness. To this end, WiMAX Forum has established recently the network architecture and protocols for providing LBS and they are included in the Network working group's release 1.5 documents. Though there have been many research efforts on location determination in Wibro networks, none of them addresses the location determination mechanism complying to Forum's recent LBS standards. This paper proposes an enhanced TDOA-RTD combined location determination mechanism, which complies to the Forum's LBS architecture.