• The Journal of the Korea Contents Association
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• v.17 no.8
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• pp.619-630
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• 2017

With the growing popularity of smart devices, various location based services have been providing to users. Recently, some location based social applications that combine social services and location based services have been emerged. The demands of a k-nearest neighbors(k-NN) query which finds k closest locations from a user location are increased in the location based social network services. In this paper, we propose an approximate k-NN query processing method for fast response time in a large number of users environments. The proposed method performs efficient stream processing using big data distributed processing technologies. In this paper, we also propose a modified grid index method for indexing a large amount of location data. The proposed query processing method first retrieves the related cells by considering a user movement. By doing so, it can make an approximate k results set. In order to show the superiority of the proposed method, we conduct various performance evaluations with the existing method.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.7
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• pp.814-818
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• 2010

Online social networking services help people to migrate social networks from offline to online. Twitter, which has achieved incredible growth, showed that an online social networking service without offline bases can become large and successful. In this paper, we propose a twitter friend notification service using user‘s twitter messages and place recognizing technology. When there is a friend in user‘s nearby place, the service notifies the information to the users. Through the friend notification service, a user can easily extend his online social network to offline.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.60-63
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• 2011

인터넷은 단순한 정보습득을 위한 공간을 넘어 사람들이 모여 교류하는 '소통의 장'으로서 역할을 하고 있다. 최근에는 타인과 끊임없이 대화를 나누고 소통하려는 인간의 기본 욕구를 반영한 서비스인 SNS(Social Network Service)가 전 세계의 주목을 받고 있다. 또한 LBS(Location-Based Service)는 GPS, Wi-Fi를 통한 위치정보를 활용하여 업무생산성 개선 및 다양한 생활 편의를 제공하는 서비스이다. 본 논문에서는 안드로이드 OS를 기반으로 LBS와 SNS를 통합한 어플리케이션을 제안한다. 개인용 모바일 정보기기인 스마트폰을 활용하여, 위치정보에 이용자 정보, SNS를 결합하여 서비스를 고도화 한다. 지인들의 위치를 기반으로 현재 상태, 트윗(Twit)을 통해 정보의 공유 및 활용을 극대화 할 수 있다. 이를 통해 사용자들이 적극적이고 용이하게 온라인 Identity를 표현하는 것을 목적으로 본 시스템을 제안한다.

• Journal of Digital Contents Society
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• v.18 no.3
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• pp.567-575
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• 2017

Location-based services play an important role in many applications such as disaster warning systems and recommendation systems. These applications often require not only location information (e.g., name, latitude, longitude, etc.) but also the impact of events (e.g., earthquake, typhoon, etc.) on locations. Recently, to provide the impact of an event on a location, how to calculate location trustiness by using multimodal information such as earthquake information and disaster sensor data is researched. In the previous approach, the linear decrement of impact value of an event is applied to obtain the location trustiness of a specific location. In this paper, we propose a new approach to enrich location trustiness, that is, the impact of an event on a location, by using social media information additionally. Firstly, we design a collecting system for earthquake information and social media data. Secondly, we present an approach of location trustiness calculation based on earthquake information. Finally, we propose a new approach to enrich location trustiness by augmenting the trustiness in spatially distributed manner based on social media.

• Journal of Digital Convergence
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• v.12 no.6
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• pp.277-287
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• 2014

In LBSNS(Location-based Social Network Service), users can share locations and communicate with others by using check-in data. The check-in data consists of POI name, category, coordinate and address of locations, nickname of users, evaluating grade of locations, related article/photo/video, and etc. If you analyze the check-in data from the location-based social network service in accordance with your situation, you can provide various customized services. Therefore, In this paper, we develop a location recommendation system based on LBSNS that can utilize the check-in data efficiently. This system analyzes the location category of the check-in data, determines the weighted value of it, and finds out the similarity between users by using the Pearson correlation coefficient. Also, it obtains the preference score of recommended locations by using the collaborated filtering algorithm and then, finds out the distance score by applying the Euclidean's algorithm to the recommended locations and the current users' locations. Finally, it recommends appropriate locations by applying the weighted value to the preference score and the distance score. In addition, this paper approved excellence of the proposed system throughout the experiment using real data.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.9
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• pp.331-336
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• 2015

On the IoT-based sensor networks, users or sensor nodes must perform a Service Discovery (SD) procedure before access to the wanted service. Current approach uses a center-concentrated Resource Directory (RD) servers or P2P technique, but these can cause a point-of-failure or flooding of SD messages. In this paper, we proposes an improved SWoT SD approach for CoAP-based sensor networks, which integrates Social Web of Things (SWoT) concept to current CoAP-based SD approach that makes up for weak points of existing systems. This new approach can perform a function like a keyword or location-based search originated from SNS, which can enhances the usability. Finally, we implemented a real system to evaluate.

• The Journal of the Korea Contents Association
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• v.11 no.7
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• pp.60-69
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• 2011

As the mobile industry has developed, people have become to pursue more delicate information exchange and close relationships between individuals through it. According to such a request, Social Networking Services have been activated based on short messages. Moreover, in combination with smart phones, the needs for adding location information is recently increasing more and more. Security and Privacy problems, however, are raised because such location information is so sensitive and may be used maliciously by someone else. Especially, storing location information of family members in a public server may become a negative factor to hinder people from utilizing such services. Therefore, this paper proposes a location based SNS service using smart phones for home community that runs on a home server in a house so that relationships between family members at home may be closer and improved through utilizing the service.

• Spatial Information Research
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• v.20 no.4
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• pp.57-67
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• 2012

Recently, market of mobile spatial information service is increasing along with enlargement of geo-spatial information utilization area and spread of smartphone. In particular, smartphone users look forward to utilizing spatial information service more easily and conveniently. Korea has the potential for spatial information technology development, but does not have enough governmental support to develop various spatial information service in mobile network environment. Hence, it is need to make governmental support plans for utilizing mobile services and promoting the related industry base on mobile spatial information. In this paper, we propose governmental action plans for utilizing mobile services and promoting the related industry by surveying mobile application/web services and analyzing demands of mobile spatial information experts.

• The Journal of Bigdata
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• v.5 no.1
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• pp.55-63
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• 2020

This study proposed an approach of clustering collective users' activities of location-based social networks using check-in data of Foursquare users in Seoul. In order to cluster the collective activities, we generated sequential rules of the activities using sequential rule mining, and then constructed activity networks based on the rules. We analyzed the activity networks to identify network structure and hub activities, and clustered the activities within the networks. Unlike previous studies that analyzed activity transition patterns of location-based social network users, this study focused on analyzing the structure and clusters of successive activities. Hubs and clusters of activities with the approach proposed in this study can be used for location-based services and marketing. They could also be used in the public sector, such as infection prevention and urban policies.

• Information and Communications Magazine
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• v.28 no.7
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• pp.59-68
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• 2011

스마트폰의 플랫폼화와 위치 측위 기술 및 관련 지도 DB의 개방은 위치 기반 서비스(LBS, Location Based Service)의 패러다임의 변화를 가져왔다. 위치 측위를 위한 HW의 제공, 위치 측위 API 및 프레임워크 제공, 지도 DB 및 각종 DB의 제공 등에 힘입어 LBS는 본격적인 성장을 맞이하고 있다. 또한 소셜 네트워크 서비스(SNS, Social Network Service), 증강 현실 (AR, Augmented Reality), 게임 등 다른 킬러앱과 연계하여 다양한 서비스를 제공하고 있으며 향후 안전 및 사고 예방 등의 공공적인 측면에서도 다양한 애플리케이션이 등장하고 있다. 그러나 이러한 급격한 패러다임의 변화는 개인정보 보호와 개인의 안전 및 편의성이라는 모순적인 이해관계 속에서 많은 문제점을 동시에 일으키고 있다. 본 고에서는 스마트폰이 가져온 LBS의 패러다임 변화 및 스마트폰 LBS의 기술, 서비스 방향을 정리하고 향후 과제 및 발전 방향에 대해서 살펴본다.