• Journal of Communications and Networks
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• v.17 no.2
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• pp.100-109
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• 2015

Mobile phone carriers face challenges from three synergistic dimensions: Wireless, social, and mobile. Despite significant advances that have been made about social networks and human mobility, respectively, our knowledge about the interplay between two layers remains largely limited, partly due to the difficulty in obtaining large-scale datasets that could offer at the same time social and mobile information across a substantial population over an extended period of time. In this paper, we take advantage of a massive, longitudinal mobile phone dataset that consists of human mobility and social network information simultaneously, allowing us to explore the impact of human mobility patterns on the underlying social network. We find that human mobility plays an important role in shaping both local and global structural properties of social network. In contrast to the lack of scale in social networks and human movements, we discovered a characteristic distance in physical space between 10 and 20 km that impacts both local clustering and modular structure in social network. We also find a surprising distinction in trajectory overlap that segments social ties into two categories. Our results are of fundamental relevance to quantitative studies of human behavior, and could serve as the basis of anchoring potential theoretical models of human behavior and building and developing new applications using social and mobile technologies.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.3
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• pp.361-365
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• 2010

In recent years, social networks come into the spotlight as the important ways to find people or share information. Especially, existing social network services based on the Internet, such as Facebook.com and Cyworld.com, are now extended into the mobile environment. A mobile phone easily collects the personal information since it is carried by the user at all times, and various types of data can be gathered together with the advance of sensor technologies. These features differentiate the mobile social network services from the previous Internet-based services. In this paper, we estimate the user's mobile social contexts like closeness and relationship between the user and surrounding people using Bayesian networks. The mobile social contexts can be employed as important information for providing mobile social network services, and experimental results on real world data have verified their possibilities.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.8
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• pp.3568-3584
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• 2016

In mobile opportunistic networks (MONs), human-carried mobile devices such as PDAs and smartphones, with the capability of short range wireless communications, could form various intermittent contacts due to the mobility of humans, and then could use the contact opportunity to communicate with each other. The dynamic changes of the network topology are closely related to the human mobility patterns. In this paper, we propose a social motivation-aware mobility model for MONs, which explains the basic laws of human mobility from the psychological point of view. We analyze and model social motivations of human mobility mainly in terms of expectancy value theory and affiliation motivation. Furthermore, we introduce a new concept of geographic functional cells, which not only incorporates the influence of geographical constraints on human mobility but also simplifies the complicated configuration of simulation areas. Lastly, we validate our model by simulating three real scenarios and comparing it with reality traces and other synthetic traces. The simulation results show that our model has a better match in the performance evaluation when applying social-based forwarding protocols like BUBBULE.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.90-92
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• 2017

Due to the popularity of social networks and the development of technology in mobile networking, the mobile social networks (MSNs) provide opportunities for the spread of information between mobile devices. As a result, understanding the information diffusion in the emerging MSNs is a critical issue. Many research studies have addressed diffusion minimization, which is a problem of how to find the proper initial k users who can effectively propagate as widely as possible in the minimum amount of time, similar to influence maximization. We address a study on association analysis among nodes in information diffusion and mobility pattern for mobile social networks. Experiments in our study were conducted in the Opportunistic Network Environment (ONE) simulator using GPS trace of mobile node, to show that the study results in MSNs. We also demonstrate that our experiments outperform other existing algorithms with various communication range and ratio of k influential nodes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.11
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• pp.934-936
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• 2013

A routing scheme for a group of mobile users for wireless ad-hoc networks is presented. The proposed scheme mines social activity patterns from wireless traces, and exploits social user group for efficient data routing among users based on a data publish approach. Simulation results based on real-world wireless traces show that our routing scheme reduces routing cost for a large mobile user group with a factor of 1.8 compared to a baseline counterpart.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.3984-3996
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• 2014

Mobile social network can be seen as a specific application of the DTN (Delay Tolerant Network), in which the information propagation can be impacted by many social behaviors of the nodes. For a specific node, its social behaviors are various. For example, the node may not be interested in the information before receiving it and may also discard the information after getting it. On the other hand, people are more willing to forward the message to his friends. These interactive behaviors between nodes can be seen as social behaviors. It is easy to see that the impact of the social behaviors is related to the social ties, which can be manifested by the structure of the social network. State of the art works often simply assumes that the social networks can be divided into some communities. At present, some works find that the structure of some social networks is scale-free. To overcome this problem, this paper proposes a theoretical model to evaluate the impact of above social behaviors in the DTN-like scale-free network. Simulation shows the accuracy of the model. Numerical results show that both social behaviors and scale-free character have significant impact on information propagation. Moreover, the impact of social behaviors is related to the scale-free character of the networks.

• International Journal of Contents
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• v.13 no.1
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• pp.1-8
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• 2017

The study aims to reveal the differences in the factors influencing portal news and news site application usages on smartphones in regard to political discussion networks, news use across multiple media platforms and news genre consumption. The results demonstrate that those factors affected both types of application usages in a different manner when controlling for demographics. The more participants conversed politics with homogeneous networks, the more they used portal news on smartphones. Conversely, the more political discussion with heterogeneous networks, the more they used news site application on smartphones. The more frequently Internet and mobile phone were employed for news source and the more soft news genre was consumed, the more the portal news application was used. However, the more frequently traditional and social media were employed for news source and the more hard news consumed, the more news site application was used. The findings imply that portal news application users may increase their likelihood of soft news consumption using Internet and mobile phones for political discussion with close social relations, while news site application users may increase their likelihood of hard news consumption using traditional and social media for political discussion with distant social relations.

• Journal of the Korean Geographical Society
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• v.41 no.5 s.116
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• pp.561-581
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• 2006

Machines, cities and bodies have been evolved together for a long time, and the recent development of information and communication technologies has transformed cities and bodies into new forms. Concerned with the relations between machines, cities and bodies, this paper explores how mobile networks are related with the physical space of the city and the psychological space of the body. The paper is organised into four main sections. First, it provides a theoretical review of the ways in which mobile networks transform urban spaces and human bodies. Secondly, it explains the generation of mobile networks through technological and institutional changes in Korea. Thirdly, it looks at the socio-spatial scales and time-space landscapes of mobile networks in relation to mobile users' motions and practices in their everyday lives. Finally, it attends to the ways in which mobile networks involve the production of paradoxical emotional spaces in relation to mobile users' emotions and desires to be dis/connected with mobile networks.

• Asia pacific journal of information systems
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• v.25 no.2
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• pp.239-264
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• 2015

This study aims to investigate the effect of message content and source user identity on information diffusion in Twitter networks. For the empirical study, we collected 11,346 tweets pertaining to the three major mobile telecom carriers in Korea for three months, from September to December 2011. These tweets generated 59,111 retweets (RTs) and were retweeted at least once. Our analysis indicates that information diffusion in Twitter in terms of RT volume is affected primarily by the type of message content, such as the inclusion of corporate social responsibility activities. However, the effect of message content on information diffusion is heterogeneous to the identity of the information source. We argue that user identity affects recipients' perception of the credibility of focal information. Our study offers insights into the information diffusion mechanism in online social networks and provides managerial implications on the strategic utilization of online social networks for marketing communications with customers.

• Journal of Intelligence and Information Systems
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• v.23 no.2
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• pp.89-105
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• 2017

As the advances of technology in mobile networking and the popularity of online social networks (OSNs), the mobile social networks (MSNs) provide opportunities for marketing strategy. Therefore, understanding the information diffusion in the emerging MSNs is a critical issue. The information diffusion address a problem of how to find the proper initial nodes who can effectively propagate as widely as possible in the minimum amount of time. We propose a new diffusion scheme, called Hotspot DBC, which is to find k influential nodes considering each node's mobility behavior in the hotspot zones. Our experiments were conducted in the Opportunistic Network Environment (ONE) using real GPS trace, to show that the proposed scheme results. In addition, we demonstrate that our proposed scheme outperforms other existing algorithms.