• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.697-698
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• 2009

모바일 기기 및 무선 통신 기술의 발달로 인하여 위치 기반 서비스의 이용이 확산되었다. 그러나 이와 같이 사용자의 정확한 위치정보를 가지고 LBS 서버에 서비스를 요청하는 것은 심각한 개인 정보 누출의 위협이 될 수 있다. 따라서 안전하고 편리한 위치기반 서비스 사용을 위한 개인 정보 보호 방법이 요구된다. 이를 위해 본 논문에서는 연속적인 위치기반 서비스를 지원하는 분산 그리드 기반 Cloaking 영역 설정 기법을 설계한다. 설계하는 기법은 분산 환경에서 연속적인 서비스를 지원하기 위해 Cloaking 영역 설정 시 필요한 정보를 분산 유지하고, 이동 확률 매트릭스 생성 및 확률 계산을 분산적으로 수행한다. 마지막으로는 모바일 사용자 사이에 발생하는 통신비용을 감소시키기 위해, 대표 노드는 해당 클러스터에서 떠난 사용자에 대한 정보를 유지하고 클러스터 내 부분 확률값의 합산시 병합노드를 사용한다.

• Journal of Korea Spatial Information System Society
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• v.10 no.4
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• pp.1-10
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• 2008

In wireless internet, the location information of the user is one of the important resources for many applications. One of these applications is Location-Based Services (LBSs) which are being popular. Because, in the LBS system, users request a location-based query to LBS servers by sending their exact location, the location information of the users can be misused by adversaries. In this regard, there must be a mechanism which can deal with privacy protection of the users. In this paper, we propose a cloaking method considering both features of K-anonymity and L-diversity. Our cloaking method creates a minimum cloaking region by finding L number of buildings (L-diversity) and then finding number of users (K-anonymity). To support this, we use a R*-tree based index structure and use filtering methods especially for the m inimum cloaking region. Finally, we show from a performance analysis that our method outperforms the existing grid based cloaking method.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.895-898
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• 2021

DB로부터 위치 데이터를 추출해오면, location visiting measure를 통해 한 개인의 장소 방문 선호도를 측정한다. 이 과정에서 위치 데이터 클러스터링 및 개인의 이동성 파악을 위한 6가지 조치를 한다. 위치 데이터 분석 결과로 얻은 이동성 통계는 LBS(Location Based System)를 포함한 다양한 분야에 적용될 수 있다. 연구의 최종 목표는 새로운 위치 데이터의 수집에 따른 방문 선호도 변화를 적용할 수 있도록 하는 location visiting measure의 자동화 시스템을 구축하는 것이다.

• Journal of Korea Spatial Information System Society
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• v.11 no.3
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• pp.19-30
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• 2009

Recent development in wireless communication technology and mobile equipment like PDA, cellular phone and GPS makes location-based services (LBSs) popular. However, because, in the LBSs, users continuously request a query to LBS servers by using their exact locations, privacy information could be in danger. Therefore, a mechanism for users' privacy protection is required for the safe and comfortable use of LBSs by mobile users. For this, this paper propose a grid-based cloaking area creation scheme supporting continuous LBSs. The proposed scheme creates a cloaking area rapidly by using grid-based cell expansion to efficiently support the continuous LBSs. In addition, to generate a cloaking area which makes the exposure probability of a mobile user to a minimum, we compute a privacy protection degree by granting weights to mobile users. Finally, we show from a performance analysis that our cloaking scheme outperforms the existing cloaking schemes, in terms of service time, privacy protection degree.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.06a
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• pp.53-60
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• 2010

위치 기반 서비스(Location-Based Services: LBS)에서 질의 요청자가 자신의 위치 정보와 원하는 질의를 전송하면, 위치 기반 서버는 이를 기반으로 질의를 처리하고 결과를 전송한다. 이 때 질의 요청자는 자신의 정확한 위치 좌표를 서버에 전송하기 때문에 개인 정보가 악용될 수 있는 위험에 노출된다. 이러한 문제를 해결하기 위하여 제안된 연구는 크게 Location Clocking 기법과 Private Information Retrieval(PIR) 기법으로 분류된다. Location Cloaking 기법은 사용자의 위치 좌표를 k-1개의 다른 사용자와 함께 묶어 하나의 Cloaking 영역을 생성하고 이를 바탕으로 질의를 처리한다. 그러나 영역에 대한 질의 후보 집합을 결과로 전송하므로 사용자에게 노출되는 POI 수가 증가하는 문제점을 지닌다. PIR은 암호화 기법으로 위치 기반 서버나 공격자에게 사용자의 위치와 질의 타입을 드러내지 않고 질의를 수행한다. 그러나 암호화 된 질의 결과로 사용자에게 데이터 전체를 전송하기 때문에 막대한 통신비용을 초래한다. 따라서 본 논문에서는 Location Cloakng과 PIR 기법의 장점을 결합하여 사용자의 개인 정보와 위치 기반 서버의 POI 정보 보호를 고려한 Approximate k-최근접점 질의 처리 알고리즘을 제안한다. 질의 전송시, 질의 요청자는 Cloaking 영역을 생성하여 위치 좌표를 감추고, 질의 결과 전송 시 Cloaking 영역에 제한된 PIR 프로토콜을 적용한다. 또한 k-최근접점 질의 수행시, 반환되는 POI의 수를 최소화하고, 정확도 높은 질의 결과를 만족하기 위해 Overlapping parameter를 적용한 색인 기법을 제안한다.

• Spatial Information Research
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• v.18 no.3
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• pp.53-62
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• 2010

Recent development in wireless communication technology, like GPS, and mobile equipments, like PDA and cellular phone, make location-based services (LBSs) popular. However, because, users continuously request a query to a server in the LBSs by using their exact locations, privacy information could be in danger. Therefore, a mechanism for users' privacy protection is required for the safe and comfortable use of LBSs by mobile users. For this, we, in this paper, propose a grid-based cloaking area creation scheme supporting continuous LBSs in peer-to-peer environment. The proposed scheme creates a cloaking area by using Chord protocol, so as to support the continuous LBSs in peer-to-peer environment. Finally, we show from a performance analysis that our cloaking scheme outperforms the existing cloaking schemes, in terms of service time.

• Spatial Information Research
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• v.20 no.5
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• pp.57-66
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• 2012

Recent development in wireless communication technology like GPS as well as mobile equipments like PDA and cellular phone makes location-based services (LBSs) popular. However, because users request a query to LBS servers by using their exact locations while moving on the road network, users' privacy may not be protected in the LBSs. Therefore, a mechanism for users' privacy protection is required for the safe and comfortable use of LBSs by mobile users. For this, we, in this paper, propose a road network distance based cloaking scheme supporting user privacy protection in location-based services. The proposed scheme creates a cloaking area by considering road network distance, in order to support the efficient and safe LBSs on the road network. Finally, we show from our performance analysis that our cloaking scheme outperforms the existing cloaking scheme in terms of cloaking area and service time.

• Journal of the Institute of Convergence Signal Processing
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• v.22 no.3
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• pp.134-140
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• 2021

This study relates to the development of a wearable device that can identify a personal location using low-power GPS and IMU based on energy harvesting. The energy harvesting technology using a piezoelectric device was applied for the development of personal location identification, and made it possible to acquire precise personal location data using GPS and IMU. As a result of the experiment, it was confirmed that GPS and IMU data were normally received. The personal location identification device can be prepared for an accident by identifying a personal location in a disaster area, etc., and the user will be able to use it easily regardless of time, place, and environment. It is expected that it can be used in various fields such as leisure and health care.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.8
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• pp.606-610
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• 2009

In Location-Based Service (LBS), a scheme to hide the exact locations of users is required for privacy protection, In this paper, we propose a grid-based cloaking method considering K-anonymity and L-diversity. For this, our method creates a minimum cloaking region by finding L number of buildings (L-diversity) and then finding number of users (K-anonymity). Especially, we use a effective filtering method for generating the minimum cloaking region in a fast way. Finally, we show from a performance analysis that our cloaking method outperforms the existing method, in terms of query processing time based on the size of cloaking regions.

• The KIPS Transactions:PartD
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• v.17D no.1
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• pp.53-58
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• 2010

This research aims to develop practical location-based services that provide users with personalized theater guide services on smart phones. In this research, we have designed and implemented a smart theater guide system for Deahakro, Seoul based on smart phones incorporating GPS. This system first identifies the current position using GPS, and maps the current position onto the map. It is designed and implemented to provide users with personalized information service about the plays and the theaters nearby the current position. It is also optimized to be useful effectively by performing on-site experiments.