• Journal of Information Technology Applications and Management
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• 제14권4호
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• pp.1-16
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• 2007

In the microcell- or picocell-based system the frequent movements of the mobile bring about excessive traffics into the networks. A mobile location estimation mechanism can facilitate both efficient resource allocation and better QoS provisioning through handoff optimization. Existing location estimation schemes consider only LOS model and have poor performance in presence of multi-path and shadowing. In this paper we study a novel scheme which can increase estimation accuracy by considering NLOS environment and other multiple decision parameters than the received signal strength.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2010년도 춘계학술대회
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• pp.127-135
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• 2010

In this paper, the u-Service system that is based on location-aware technology is designed for a silver town. It provides services such as emergency call, intelligent elevator operation, and hands-free door access based on the location of the residents with personal device as called smart tag. It can also be applied to other service areas such as the location-aware u-Service for Hospital, high-rising complex building, APT, etc.

• 전기학회논문지
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• 제65권4호
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• pp.704-710
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• 2016

In this paper, we proposed pole position detection system for providing exact location information to users. The proposed system consists of pole recognition part and pole number recognition part. Above all, exact pole recognition is carried out by PDD(Pole Detection Device). And recognition of pole number is performed by PID(Pole Inspection Device). Acquired image by using line scan camera is judged whether it is free bracket or not through image processing. When it is judged as free bracket, pole number image is acquired by OCR camera and recognized by OCR. By recognizing pole number, exact location information is provided to user.

• 정보처리학회논문지A
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• 제13A권5호
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• pp.435-444
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• 2006

위치기반서비스(LBS: Location-Based Services)의 이용자가 급증함으로써 최근 위치 트리거(Location Trigger) 서비스에 대한 다양한 응용분야가 등장하고 있다. 위치 트리거는 사용자의 이동 위치를 감지하여 특정한 지역에 진입, 존재, 이탈할 경우 사용자에게 단문문자서비스(SMS), 전자메일 등을 통하여 알리거나 또는 사용자에 의해 미리 정의된 특정한 서비스를 제공하는 기술이다 기존에 이러한 위치 트리거 기술은 위치 제공 서버에 주기적으로 위치정보를 요청하여 처리해 왔으나 LBS 서비스 가입자가 증가할수록 서버 및 통신 부하로 인하여 시스템의 성능 저하를 초래하게 된다. 이에 본 논문에서는 위치 트리거를 처리함에 있어서 이동통신망의 위치서버의 부하를 줄이고 모바일 단말기에 임베디드 된 GPS 디바이스의 전력 소모량을 최소화하는 멀티레벨 위치 트리거 방법에 대하여 연구하였다. 실제 본 논문에서 제시하는 방법을 설계하고 테스트베드를 구축하여 성능을 평가함으로써 위치 트리거 기술의 성능 향상에 기여하였다.

• 디지털산업정보학회논문지
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• 제10권3호
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• pp.151-159
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• 2014

Recently, spread of large amount Smartphones made users to download location-based service applications, which provided by application developers. These location-based service applications are convenient tool for users. Location-based service use technology to find location of user and provide information of user's location. Leakage of information of user's location and expose of privacy life raised new controversy. In this thesis, it will analyze relations of increase of Smartphone market, usage of Location-based service and severity of personal information leakage. Also, it will analyze examples of user's case of damage which caused by leakage personal information and find solutions to reduce damage of personal information leakage. In research, it will find cases of damage that cause by Location-based service. Also it will analyze and research cases of damage and present with graph and chart. In conclusion, to reduce and prevent from damage which caused by leakage personal information, it is important that users and application developers to realize danger of private and personal information leakage. Also, user's personal information must deal with cautiously and application developers have to research and develop the application with powerful security.

• 한국전자통신학회논문지
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• 제8권12호
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• pp.1883-1890
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• 2013

위치 추정 기술 (LDT, Location Detection Technology)은 자원관리 및 통신 서비스의 품질을 향상시키기 위한 무선통신 분야에서 사용되고 있는 LBS(Location Based Service)의 핵심기술 중 하나이다. 이동국(MS, mobile station)의 위치는 세 개의 기지국(BS, base station)들의 좌표와 이동국과 기지국들 사이의 거리에 상응하는 반지름에 기초한 세 개의 원들에 기반한 도래시간(TOA, Time of Arrival)기법을 사용하여 추정된다. 삼각변 측량법을 이용하여 정확한 이동국의 위치를 추정하기 위해서는 세 개의 원들이 한 점에서 만나야 하는데, 이동국과 기지국의 거리를 추정하기 위한 시간지연 개수와 전송 주파수에 따라 원들의 반지름이 증가하여 세 개의 원들이 한 점에서 만나지 못하는 경우들이 발생한다. 반지름이 증가된 세 개의 원들은 여섯 개의 교점을 가지게 되고 이 교점들 중 세 개의 교점들이 특정 이동국의 좌표에 가까이 위치하게 된다. 본 논문에서는 여섯 개의 전체 교점들 중에서 세 개의 내부 교점들을 선택하는 TOA 삼각변 측량법을 위한 최단 거리 알고리즘을 제안한다. 제안된 방법은 여섯 개의 교점들 중 이동국의 좌표와 가장 가까운 세 개의 교점을 선택하고, 선택된 교점들의 평균 좌표를 특정 이동국의 위치로 결정한다. 제안된 알고리즘의 성능은 컴퓨터 시뮬레이션 예를 통해 확인된다.

• Journal of Communications and Networks
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• 제17권2호
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• pp.126-132
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• 2015

In mobile computing research area, it is highly desirable to understand the characteristics of user movement so that the user friendly location aware services could be rendered effectively. Location based social networks (LBSNs) have flourished recently and are of great potential for movement behavior exploration and datadriven application design. While there have been some efforts on user check-in movement behavior in LBSNs, they lack comprehensive analysis of social influence on them. To this end, the social-spatial influence and social-temporal influence are analyzed synthetically in this paper based on the related information exposed in LBSNs. The check-in movement behaviors of users are found to be affected by their social friendships both from spatial and temporal dimensions. Furthermore, a probabilistic model of user mobile behavior is proposed, incorporating the comprehensive social influence model with extent personal preference model. The experimental results validate that our proposed model can improve prediction accuracy compared to the state-of-the-art social historical model considering temporal information (SHM+T), which mainly studies the temporal cyclic patterns and uses them to model user mobility, while being with affordable complexity.

• Industrial Engineering and Management Systems
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• 제15권3호
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• pp.197-205
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• 2016

The public services closely related to the daily lives of the Japanese people, such as firefighting, police or primary school education, are largely financed by the local governments. As the population as a whole in Japan declines, the population in local regions are forecasted to experience particularly rapid decline in the future, and it is inevitable to reduce the cost of public services provided by the local governments to keep their financial basis sustainable. In order to provide public services to the people properly and fairly, the local governments own and utilize their public facilities, such as fire stations, police stations or primary schools. On the other hand, we have to secure the accessibility, which is the condition of accessing a facility easily in a whole local city including the high population density area and low population density area. In this paper, we propose a method of determining the number of future facilities and its facility locations in which we maintain the present accessibility. In our proposed method, we determine them comparing the accessibility measurement calculated by facility location model using the present and future population. We adopted k-centdian model as the facility location model, which can secure the accessibility in a whole local city determining the weights of both areas. We applied our proposed method to fire station in Iwaki city, Japan. The results suggested that 7 facilities would be reduced in 2064, after 50 years from 2014. Additionally, we confirmed that the future facility location had secured accessibility in both high and low population density area.

• 정보통신설비학회논문지
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• 제11권2호
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• pp.52-57
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• 2012

In this paper describe configuration about QCM system for image processing device. It presents that QCM's image processing board video from the camera recognized by the PLC's battery removable exact location coordinates to the robot image processing technology to deliver. In addition, QCM video image processing technology for improved data reliability is described. In this paper define the landmarks of battery for obtaining the location coordinates and verify battery the location coordinates acquisition process from field tests of the QCM/QTPE-BUS Battery Exchange System.

• International Journal of Advanced Culture Technology
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• 제2권2호
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• pp.15-18
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• 2014

This paper presents a sensor location decision making method respect to Container-Grown Seedlings in view of precision agriculture (PA) when sensors involved in tree container measure received signal strength (RSS) or time-of-arrival (TOA) between themselves and neighboring sensors. A small fraction of sensors in the container-grown seedlings system have a known location, whereas the remaining locations must be estimated. We derive Rao-Cramer bounds and maximum-likelihood estimators under Gaussian and log-normal models for the TOA and RSS measurements, respectively.