• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.5
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• pp.1653-1670
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• 2022

The fear that location privacy may be compromised greatly hinders the development of location-based service. Accordingly, some schemes based on the distributed architecture in peer-to-peer network for location privacy protection are proposed. Most of them assume that mobile terminals are mutually trusted, but this does not conform to realistic scenes, and they cannot make requirements for the level of location privacy protection. Therefore, this paper proposes a scheme for location attribute-based security authentication and private sharing data group, so that they trust each other in peer-to-peer network and the trusted but curious mobile terminal cannot access the initiator's query request. A new identifier is designed to allow mobile terminals to customize the protection strength. In addition, the caching mechanism is introduced considering the cache capacity, and a cache replacement policy based on deep reinforcement learning is proposed to reduce communications with location-based service server for achieving location privacy protection. Experiments show the effectiveness and efficiency of the proposed scheme.

• Journal of Korea Multimedia Society
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• v.17 no.8
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• pp.946-952
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• 2014

Mobility prediction is one of hot topics using location history information. It is useful for not only user-level applications such as people finder and recommendation sharing service but also for system-level applications such as hand-off management, resource allocation, and quality of service of wireless services. Most of current prediction techniques often use a set of significant locations without taking into account possible location information changes for prediction. Markov-based, LZ-based and Prediction by Pattern Matching techniques consider interesting locations to enhance the prediction accuracy, but they do not consider interesting location changes. In our paper, we propose an algorithm which integrates the changing or emerging new location information. This approach is based on Active LeZi algorithm, but both of new location and all possible location contexts will be updated in the tree with the fixed depth. Furthermore, the tree will also be updated even when there is no new location detected but the expected route is changed. We find that our algorithm is adaptive to predict next location. We evaluate our proposed system on a part of Dartmouth dataset consisting of 1026 users. An accuracy rate of more than 84% is achieved.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.12B
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• pp.1686-1694
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• 2001

In this paper, we analyze capacities of spectrum sharing scheme for both reverse link and forward link in hierachical CDMA cellular systems with Hot-spot microcell. Capacity analysis is performed through Monte-Carlo simulation by considering microcell radius, location of microcell. and transmission power ratio of microoell to macrocell. From simulation results, we analyzed these effects and derived a general design approach. In addition, the performance of spectrum sharing scheme for each link is analyzed in the capacity plane.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.448-450
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• 2007

Peer-to-Peer system has emerged as a popular model aiming at further utilizing Internet information and resources, complementing the available client-server services. However, the mechanism of peers randomly choosing logical neighbors without any knowledge about underlying physical location aware topology can cause serious performance degradation. In this paper, we consider the network distance between peers so that it helps peers select neighbors located at the nearest when they exchange queries for sharing of resources. To reduce the unnecessary signaling traffic and delay of query exchange, we propose a location aware topology based Hybrid P2P system. This system calculates the network distance which combines the direct measurement such as RTT (Round Trip Time) with geographic space of peers using IP address

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.621-624
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• 2013

Mobile Cloud Computing is today's emerging technology. Customers enjoy the services and application from this combination of mobile technology and cloud computing. Beside all these benefits it also increases the concerns regarding privacy of users, while interacting with this new paradigm One of the services is Location based services, but to get their required services user has to give his/her current location to the LBS provider that is violation of location privacy of mobile client. Many approaches are in literature for preserve location privacy but some has computation restriction and some suffer from lack of privacy. In this paper we proposed a novel idea that not only efficient in its protocol but also completely preserves the user's privacy. The result shows that by sharing just service name and a large enough geographic area (e.g. a city) user gets required information from the server by doing little client side processing We perform experiments at client side by developing and testing an android based mobile client application to support our argument.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.377-379
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• 2022

POI refers to the point of Interest in Location-Based Social Networks (LBSNs). With the rapid development of mobile devices, GPS, and the Web (web2.0 and 3.0), LBSNs have attracted many users to share their information, physical location (real-time location), and interesting places. The tremendous demand of the user in LBSNs leads the recommendation systems (RSs) to become more widespread attention. Recommendation systems assist users in discovering interesting local attractions or facilities and help social network service (SNS) providers based on user locations. Therefore, it plays a vital role in LBSNs, namely POI recommendation system. In the machine learning model, most of the training data are stored in the centralized data storage, so information that belongs to the user will store in the centralized storage, and users may face privacy issues. Moreover, sharing the information may have safety concerns because of uploading or sharing their real-time location with others through social network media. According to the privacy concern issue, the paper proposes a recommendation model to prevent user privacy and eliminate traditional RS problems such as cold-start and data sparsity.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.484-488
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• 2008

In ubiquitous environments, there are a large number of various mobile devices everywhere. Recently, many studies have been research on distributed resources sharing in this ubiquitous environments. However, the problems with this researches are no considering user's situation and preference. Therefore in this paper, we suggest the personalized resource sharing system considering user's situation and preference. Our system is aware of user's situation by using user's schedule information and a context information such as the time and location information and recommends personalized resources by using the simple weighted scheme. We prove our situation-aware based personalized resource sharing system by using a meeting scenario.

• Journal of Digital Contents Society
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• v.9 no.1
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• pp.77-86
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• 2008

False sharing is a result of co-location of unrelated data in the same unit of memory coherency, and is one source of unnecessary overhead being of no help to keep the memory coherency in multiprocessor systems. Moreover, the damage caused by false sharing becomes large in proportion to the granularity of memory coherency. To reduce false sharing in page-based DSM systems, it is necessary to allocate unrelated data objects that have different access patterns into the separate shared pages. In this paper we propose sized and call-site tracing-based shared memory allocator, shortly SCSTallocator. SCSTallocator places each data object requested from the different call-sites into the separate shared pages, and at the same time places each data object that has different size into different shared pages. Consequently data objects that have the different call-site and different object size prohibited from being allocated to the same shared page. Our observations show that our SCSTallocator outperforms the existing dynamic shared memory allocators. By combining the two existing allocation technique, we can reduce a considerable amount of false sharing misses.

• Journal of Fashion Business
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• v.19 no.6
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• pp.82-100
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• 2015

Mobile fashion apps present much opportunity for marketers to engage consumers, however not all apps provide enough functions for their targeted audience. This study aims to determine how mobile fashion apps can be used to build brand community with consumer engagement. Qualitative data on fashion mobile apps were collected from the Apple app store and Android market during the spring and summer of 2015. A total of 110 fashion mobile apps were collected;, 50 apps were identified as apparel brands that either manufacture or sell apparel to consumers, which we categorized as "brand" fashion apps, and the remaining 60 were categorized as "non-brand" fashion apps. The result of the study can be summarized as below. The 60 non-brand fashion apps were grouped into 5 app types: shopping, searching, sharing, organizational, and informational. The main functions are for informational use and shopping needs, since at least half (31 apps) are used for either retrieving information or for shopping. However, in contrast, social networking and location were infrequent and not commonly utilized by these apps. The most common type of non-brand fashion apps available were shopping apps;, many shopping apps enable users to shop from several different websites and save their items into one universal shopping cart so that they only check out once. Most of these apps are informational and help consumers make more informed decisions on purchases;, in addition many offer location services to help consumers find these items in store. While these apps perform several functions, they do not link to social media. The 50 brand apps were grouped into 5 brand types: athletic, casual, fast fashion, luxury, and retailer. These apps were also checked for attributes to determine their functionality. The result shows that the main functions of brand fashion apps are for information (82% of the 50 apps) as well as location searching (72% of 50 apps). Conversely, these apps do not offer any photo sharing, and very few have organizational or community functions. Fashion mobile apps and m-marketing elements: To build brand community, mobile apps can be designed to motivate consumer's engagement with brands. The motivations of fashion mobile apps are useful in developing fashion mobile apps. Entertainment motives can be fulfilled with multimedia attributes, functionality motives are satisfied with organizational and location-based features, information motives with informational service, socialization with community and social network, learning and intellectual stimulation from informational attributes, and trend following through photo sharing. The 8 key attributes of mobile apps can correspond to the 4 m-marketing elements (i.e., Informative content, multimedia, interactions, and product promotions) that are further intertwined with m-branding elements. App Attributes and M-Marketing aim to Build Brand Community;, the eight key attributes can impact on 4 m-branding elements, which further contribute to building brand community by affecting consumers' perceptions of brands preference and advocacy, and their likelihood to be loyal.

• Journal of Family Resource Management and Policy Review
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• v.16 no.2
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• pp.187-210
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• 2012

Pumasi and Cooperative Child Care Sharing have had positive results among participants and show possibilities of spreading out to the community in general. However, performance was not proved where it is clarified, and the experience of 23 local Healthy Family Support Centers have that ran the demonstration project were unable to be collected. It is the point of time when the initial backing up is important but the centers do not have the systematic support. Therefore, this research presents an effective management plan through qualitative research involving Pumasi participants and person in charge. The operation strategies by the stage of the project were as follows: First, in the beginning stage, the person in charge establishes the target and vision of the project. Second, when comprising the Pumasi team, it was necessary to consider their characteristics according to the team organization subjects. Third, it is necessary to extend the turn-off time and provide many programs so that the various populations can participate. Fourth, in the advertising step, word of mouth and individual contact needs to be utilized. Fifth, in a medium or small city or an urban-rural complex area, the person in charge should support the participants' Pumasi activities. Sixth, various programs such as a passive and active parent education program and Pumasi education program for the leader needs to be provided for the activation of Pumasi activities. Lastly, a cooperative child care sharing location needs to be constructed by the duality system of the base space and outer space. In this location, the inside play space for the children is essential.