• Journal of Internet Computing and Services
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• v.9 no.3
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• pp.1-8
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• 2008

With growing interest in location-based service (LBS), there is increasing necessity for nearest neighbor (NN) search through query while the user is moving. NN search in such a dynamic environment has been performed through the repeated applicaton of the NN method to the search segment, but this increases search cost because of unnecessary redundant calculation. We propose slabbed continuous nearest neighbor (Slabbed_CNN) search, which is a new method that searches CNN in the search segment while moving, Slabbed_CNN reduces calculation costs and provides faster services than existing CNN by reducing the search area and calculation cost of the existing CNN method through reducing the search segment using slabs.

• Asia pacific journal of information systems
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• v.24 no.3
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• pp.299-323
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• 2014

The reason location based service is drawing attention recently is because smart phones are being supplied increasingly. Smart phone, basically equipped with GPS that can identify location information, has the advantage that it can provide contents and services suitable for the user by identifying user location accurately. Offering such diverse advantages, location based services are increasingly used. In addition, for use of location based services, release of user's personal information and location data is essentially required. Regarding personal information and location data, in addition to IT companies, general companies also are conducting various profitable businesses and sales activities based on personal information, and in particular, personal location data, comprehending high value of use among personal information, are drawing high attentions. Increase in demand of personal information is raising the risk of personal information infringement, and infringements of personal location data also are increasing in frequency and degree. Therefore, infringements of personal information should be minimized through user's action and efforts to reinforce security along with Act on the Protection of Personal Information and Act on the Protection of Location Information. This study aimed to improve the importance of personal information privacy by empirically analyzing the effect of perceived values on the intention to strengthen location information security and continuously use location information for users who received location-based services (LBS) in mobile environments with the privacy calculation model of benefits and risks as a theoretical background. This study regarded situation-based provision, the benefit which users perceived while using location-based services, and the risk related to personal location information, a risk which occurs while using services, as independent variables and investigated the perceived values of the two variables. It also examined whether there were efforts to reduce risks related to personal location information according to the values of location- based services, which consumers perceived through the intention to strengthen security. Furthermore, it presented a study model which intended to investigate the effect of perceived values and intention of strengthening security on the continuous use of location-based services. A survey was conducted for three hundred ten users who had received location-based services via their smartphones to verify study hypotheses. Three hundred four questionnaires except problematic ones were collected. The hypotheses were verified, using a statistical method and a logical basis was presented. An empirical analysis was made on the data collected through the survey with SPSS 12.0 and SmartPLS 2.0 to verify respondents' demographic characteristics, an exploratory factor analysis and the appropriateness of the study model. As a result, it was shown that the users who had received location-based services were significantly influenced by the perceived value of their benefits, but risk related to location information did not have an effect on consumers' perceived values. Even though users perceived the risk related to personal location information while using services, it was viewed that users' perceived value had nothing to do with the use of location-based services. However, it was shown that users significantly responded to the intention of strengthening security in relation to location information risks and tended to use services continuously, strengthening positive efforts for security when their perceived values were high.

• The Journal of the Korea Contents Association
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• v.14 no.10
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• pp.454-462
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• 2014

With the development of location aware technologies and mobile devices, location-based services have been studied. To provide location-based services, many researchers proposed methods for processing various query types with Mapreduce(MR). One of the proposed methods, is a Reverse k-nearest neighbor(RkNN) query processing method with MR. However, the existing methods spend too much cost to process the continuous RkNN query. In this paper, we propose an efficient continuous RkNN query processing method with MR to resolve the problems of the existing methods. The proposed method uses the 60-degree-pruning method. The proposed method does not need to reprocess the query for continuous query processing because the proposed method draws and monitors the monitoring area including the candidate objects of a RkNN query. In order to show the superiority of the proposed method, we compare it with the query processing performance of the existing method.

• 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.

• 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.

• Journal of KIISE:Databases
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• v.37 no.5
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• pp.250-257
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• 2010

As the variant of skyline query processing, reverse skyline Queries have been studied. However, the existing methods for processing reverse skyline Queries have the limitation of service domains and spend high costs to provide various location-based services. In this paper, we propose a new reverse skyline Query processing method that efficiently processes a query with the objects in metric spaces. In addition, the proposed method also processes continuous reverse skyline queries efficiently. In order to show the superiority of the proposed scheme, we compare it with the previous reverse skyline 벼ery processing scheme in various environments. As a result, the proposed method achieves better performance than the existing method.

• Journal of the Korea Society of Computer and Information
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• v.18 no.3
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• pp.47-57
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• 2013

Location privacy has been a serious concern for mobile users who use location-based services to acquire geographical location continuously. Spatial cloaking technique is a well-known privacy preserving method, which blurs an exact user location into a cloaked area to meet privacy requirements. However, cloaking for continuous moving object suffers from cloaked area size problem as it is unlikely for all objects travel in the same direction. In this paper, we propose a grid-based privacy preservation method with an improved Earth Mover's Distance(EMD) metric weight update scheme for semantic cloaking. We also define a representative cloaking area which protects continuous location privacy for moving users. Experimental implementation and evaluation exhibit that our proposed method renders good efficiency and scalability in cloaking processing time and area size control. We also show that our proposed method outperforms the existing method by successfully protects location privacy of continuous moving objects against various adversaries.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06a
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• pp.19-20
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• 2010

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.9
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• pp.4771-4787
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• 2019

Aimed at the disclosure risk of mobile terminal user's location privacy in location-based services, a location-privacy protection scheme based on similar trajectory substitution is proposed. On the basis of the anonymized identities of users and candidates who request LBS, this scheme adopts trajectory similarity function to select the candidate whose trajectory is the most similar to user's at certain time intervals, then the selected candidate substitutes user to send LBS request, so as to protect user's privacy like identity, query and trajectory. Security analyses prove that this scheme is able to guarantee such security features as anonymity, non-forgeability, resistance to continuous query tracing attack and wiretapping attack. And the results of simulation experiment demonstrate that this scheme remarkably improve the optimal candidate' trajectory similarity and selection efficiency.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.114.4-114
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• 2001

Recently, variety services are more and more developed due to supply of PDA, cellular phone, and etc. Also, a services based on location information are very helpful in traffic, shopping, and emergency. Thus the user position is positively necessary for these services. One of the latest applications in GPS is the E911 call service for wireless phones. In this case, current GPS Navigation accuracy meets the FCC requirements but the hardware size and power consumption of GPS is issued for implementation. And, some case of applications need to snapshot location solution with fast TTFF(Time-To-Fist-Fix) than continuous location solution. The software GPS receiver could be the solution ...