• KIPS Transactions on Computer and Communication Systems
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• v.2 no.12
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• pp.533-540
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• 2013

Anonymity is the one of main reasons for substantial improvement of Internet. It encourages various users to express their opinion freely and helps Internet based distributed systems vitalize. But, anonymity can cause unexpected threats because personal information of an online user is hidden. Especially, distributed systems are threatened by Sybil attack, where one malicious user creates and manages multiple fake online identities. To prevent Sybil attack, the traditional solutions include increasing the complexity of identity generation and mapping online identities to real-world identities. But, even though the high complexity of identity generation increases the generation cost of Sybil identities, eventually they are generated and there is no further way to suppress their activity. Also, the mapping between online identities and real identities may cause high possibility of losing anonymity. Recently, some methods using online social network to prevent Sybil attack are researched. In this paper, a new method is proposed for extracting a user's system-wide Sybil-resistant trust value by using the properties embedded in online social network graphs. The proposed method can be categorized into 3 types based on sampling and decision strategies. By using graphs sampled from Facebook, the performance of the 3 types of the proposed method is evaluated. Moreover, the impact of Sybil attack on nodes with different characteristics is evaluated in order to understand the behavior of Sybil attack.

• Journal of Digital Convergence
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• v.19 no.7
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• pp.147-154
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• 2021

The pandemic age came to us after the COVID19 broke out in the early of 2020, which resulted in many changes in our everyday life. One of the changes is non-contact transactions in economic activities, especially contact-free financial transactions are ever-increasing activities in the pandemic age. In non-contact financial transactions, security and trust are important issues that users are concerned about the most. So the paper examines how security and trust have effects on the attitudes of bank customers who use mobile banking applications on their smartphones. The study conducted factor ananlysis to extract research constructs using survey data gathered during Nobember of 2020 through February of 2021 across the nation. After extracting the constructs, the study checked validity, sampling adequacy, and internal reliability with KMO, Bartlett's test, and Crombach Alpha respectively. To make sure the purpose of the study, I do regression analysis. All factors of attitude had impacts on willingness on both of transactions and purchasing financial products. The results could give guidelines banks which want to attract more customers in open-banking environment through ever-more secure and trusty mobile banking application.

• Knowledge Management Research
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• v.22 no.1
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• pp.287-308
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• 2021

This study aims to explore how the effects of the perceived social presence on trust and live chat adoption intention vary with the types of live chats in e-commerce context. As technology develops, live chat with the seller in e-commerce is rapidly replaced by AI-assisted live chat called chat-bot. However, it is not well known how the buyers perceive the difference between the chat with seller and the chat-bot. This study therefore proposes first, the perceived social presence toward the seller will influence trust and the live chat adoption. Second, the effects of social presence will be stronger when using live chat with seller than using chat-bot. To validate, we collect data from 232 e-commerce users and confirm the first proposition. However, the higher level of the social presence effect of live chat with seller is not clearly revealed. This study is expected to provide researchers and managers who are interested in AI-based chatbots with useful theoretical and practical implications.

• Korean journal of communication and information
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• v.46
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• pp.177-211
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• 2009

The purpose of this study is to investigate how portal users recognize the role and function of the portal as a press. Furthermore, this study aims to analyze the pattern of portal news use among portal users and their recognition about replies to news. For this, we conducted online survey of 1,036 people aged from 15 to 45, who used portal site at least once a week. As a result, most users(70.8%) agreed that portal news played a role as a press with other media. In addition, six out of ten agreed that portal news set the agenda of society. These results suggest that portal users think highly of the social impact and responsibility of portal in society. However, about 40 percent of respondents said that they did not trust in information shown in replies to news and many replies to news were written by albeit. Six out of ten thought that replies to news were written by intention. Therefore, to manage the quality of replies to news is necessary to secure the credibility of portal news. As respondents use portal news often, they tend to think that portals are convenient to use and their social impact is very large, at the same time considering their sensation and commercialization. On the other hand, as portal users use the internet often, they tend to think that portals are convenient to use and their social impact is immense. However, there was no significant relationship between income and portal users' recognition of portals as the press.

• Korean Journal of Human Ecology
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• v.14 no.1
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• pp.155-165
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• 2005

The purpose of this study is 1) to investigate the effects of Internet apparel store attributes, shopping values, Internet usage, and consumers' characteristics on consumers' Internet apparel purchasing behavior; and 2) to identify the influence of Internet apparel store attributes, Internet usage, and consumers' characteristics on the Internet apparel purchasing behavior of hedonic or utilitarian consumers. The data were collected via an online survey. A total of 4,254 Internet users participated in this survey. Only 589 out of the users' reponses were used as a sample for this research, because those users had previously experienced Internet apparel purchasing. Factor analysis revealed five dimensions of Internet apparel store attributes: site design/navigation, promotion programs, trust, product assortment/ information, and customer service. Based on the respondents' shopping value scores, we identified them as hedonic or utilitarian consumers. Through multiple regression analyses, site design/navigation and promotion programs among store attribute variables, hedonistic or utilitarian shopping values, the number of years on the Internet, income, and educational level were found to be significant predictors of Internet apparel shopping frequency. Among them, hedonistic shopping values were the best predictor of Internet apparel purchasing frequency. Based on the Internet apparel purchasers' shopping value, purchasers were divided into two groups. For hedonic Internet apparel shoppers, the number of years on the Internet, educational level, sex, age, and income were significant predictors of Internet apparel shopping behavior. On the other hand, promotion programs among store attribute variables was the only significant factor that affects utilitarian consumers' Internet apparel shopping behavior.

• Knowledge Management Research
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• v.16 no.3
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• pp.23-40
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• 2015

Despite much interest and investment in the Internet of Things (IoT) which expand the Internet to a ubiquitous network including objects in the physical world, there is growing concerns of privacy protections. Because the risk of privacy invasion is higher in IoT environments than ever before, privacy need to be a key issue in the diffusion of IoT. Considering that the privacy concern is a critical barrier for user to adopt information technologies, it is important to investigate users' privacy concerns related to IoT applications. From the triad perspective (i.e., risk on technology, risk on service provider, and trust on legislation), this study aims to examine users' privacy concerns in the context of activity trackers.

• The Journal of Information Systems
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• v.26 no.4
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• pp.39-62
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• 2017

Purpose The purpose of this study is to investigate the factors which affect users' fatigue and reluctant intention of using a SNS. In particular, this study focused on the fatigue of SNS users, as the recent excessive use of SNS has led to negative effects such as invasion of privacy, addition and social overload. fatigue This research will explain how producing adverse effects by using SNS caused psychological and mental depression. Previous researches explained that mental fatigue associated with SNS is not simple one and it is complicated with various psychological factors. Considering this fact, this study introduced a behavioral economics concept and a social comparison theory in the research model. Design/methodology/approach For research purposes, this study developed research hypotheses in order to empirically examine the factors that affect SNS users' fatigue and reluctant intention. The empirical research was based on a poll done through 800 research candidates in the SNS fields and the final 451 responses were collected and used in statistical data analysis. The adaptability, trust, and validity to measurement model were verified and the structural relationship in the research model was analyzed through these 451 responses. Findings First of all, maintenance fatigue of SNS had a positive significant effect on coupling and fatigue of SNS and information privacy had a non-significant effect on fatigue. Second, coupling had a negative significant effect on rational inattention, however, perceived cost had a non-significant effect on rational inattention. Third, lateral/upward comparison had a positive significant on user's negative emotions. Meanwhile, user's negative emotions did not have a significant effect on rational inattention.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.6
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• pp.1311-1326
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• 2010

Peer-to-peer (P2P) networks consume the most bandwidth in the current Internet and file sharing accounts for the majority of the P2P traffic. Thus it is important for a P2P file sharing application to be efficient in bandwidth consumption. Bandwidth consumption as much as downloaded file sizes is inevitable, but those in file search and bad downloads, e.g. wrong, corrupted, or malicious file downloads, are overheads. In this paper, we target to reduce these overheads even in the presence of high volume of malicious users and their bad files. Sybil attacks are the example of such hostile environment. Sybil attacker creates a large number of identities (Sybil nodes) and unfairly influences the system. When a large portion of the system is subverted, either in terms of the number of users or the number of files shared in the system, the overheads due to the bad downloads rapidly increase. We propose ELiSyR, a file search protocol that can tolerate such a hostile environment. ELiSyR uses social networks for P2P file search and finds benign files in 71% of searches even when more than half of the users are malicious. Furthermore, ELiSyR provides similar success with less bandwidth than other general efforts against Sybil attacks. We compare our algorithm to SybilGuard, SybilLimit and EigenTrust in terms of bandwidth consumption and the likelihood of bad downloads. Our algorithm shows lower bandwidth consumption, similar chances of bad downloads and fairer distribution of computation loads than these general efforts. In return, our algorithm takes more rounds of search than them. However the time required for search is usually much less than the time required for downloads, so the delay in search is justifiable compared to the cost of bad downloads and subsequent re-search and downloads.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.30 no.4
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• pp.135-156
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• 2019

The purpose of this study is to examine the influence of perceived relational benefits of senior library users on the relationship quality and intent to relationship continuity. This study was conducted 50+ public library users through the survey, and 185 subjects were analyzed. The results showed that relational benefits mediated by relationship quality affect intent to relationship continuity. Particularly, functional benefit among the relational benefits had a great effect on intent to relationship continuity, mediated by relationship quality. Commitment among relational quality had a great effect on intent to relationship continuity. These findings suggest marketing policy implications to develop service policy for senior library users.

• Journal of KIISE
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• v.43 no.1
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• pp.96-105
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• 2016

Recently, social network services have changed by moving towards an open platform where, as well as simply allowing the building of relationships among users, various types of information can be generated and shared. Since existing user reputation management methods evaluate user reliability based on user profiles, explicit relations, and evaluation, they are not suitable for determining user reliability on social media due to few explicit evaluation. In this paper, we analyze social activities on social media and propose a new user reputation management method that considers implicit evaluation as well as explicit evaluation. The proposed method derives positive and negative implicit evaluation from social activities, and generates user reputation information by field in order to consider user expertise. It also considers the number of users that participate in evaluation in order to measure user influence. As a result, it generates the reputation information of users who have no explicit evaluation and creates user reputation information that is more suitable for social media.