• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.9
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• pp.4529-4548
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• 2016

DDoS attacks have had a devastating effect on the Internet, which can cause millions of dollars of damage within hours or even minutes. In this paper we propose a practical dynamic defense approach that overcomes the shortage of static defense mechanisms. Our approach employs a group of SDN-based proxy switches to relay data flow between users and servers. By substituting backup proxy switches for attacked ones and reassigning suspect users onto the new proxy switches, innocent users are isolated and saved from malicious attackers through a sequence of remapping process. In order to improve the speed of attacker segregation, we have designed and implemented an efficient greedy algorithm which has been demonstrated to have little influence on legitimate traffic. Simulations, which were then performed with the open source controller Ryu, show that our approach is effective in alleviating DDoS attacks and quarantining the attackers by numerable remapping process. The simulations also demonstrate that our dynamic defense imposes little effect on legitimate users, and the overhead introduced by remapping procedure is acceptable.

• Journal of Korea Society of Industrial Information Systems
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• v.7 no.5
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• pp.21-28
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• 2002

With the proliferation of internet and an increase in internet users, several kinds of vast information are provided to users on the internet. It is increasing in the need of personalization service by filtering user preferred news among various news documents provided through several news servers.. In this paper, we implemented a filtering agent system to meet to demand for personalized news service. In the proposed system, Kohonen network is used to train keywords provided by users and to classify news groups. Resulting from that, the personalized new service is achieved. After we trained and tested the filtering agent, we could provide users news groups with their intention.

• Journal of Nutrition and Health
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• v.34 no.8
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• pp.946-955
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• 2001

This study was performed to investigate the dietary supplement use and related factors by college students attending in web class. One thousand four hundred college students(male: 632, female: 768) were participated in this study. The questionnaire about dietary supplements use, demographic characteristics, eating behavior, health-related lifestyles, nutrient intake was self-administered and the data were obtained via internet or mail. Dietary supplements were taken by 63.6%(male : 62.2%, female : 64.2%) of subjects. The higher concern about nutrition and health, the higher the incidence of dietary supplements taking was(p < 0.05). Dietary supplement users were satisfied more than non-users about meal served(p < 0.05). Supplements used by most male students were lactic acid beverage, Chinese medicine, geigogi geisoju and multivitamin, Chinese medicine, fiber-processed flood for female students. Most of dietary supplement users answered that the sources of information on supplements were 'friend, family or relatives' and 'TV or radio'. Dietary supplement users were taking significantly more nutrients compared to non-use. Therefore, it may be necessary to provide nutrition information and education which show that balanced diet is the best nutritional strategy for health promotion and diet supplements can be helpful in deficient state nutrients.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.1
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• pp.421-433
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• 2015

Recently, there have been fast-growing social network services based on the Internet environment and web technology development, the prevalence of smartphones, etc. Social networks also allow the users to convey the information and news so that they have a great influence on the public opinion formed by social interaction among users as well as the spread of information. On the other hand, these social networks also serve as perfect environments for rampant malware. Malware is rapidly being spread because relationships are formed on trust among the users. In this paper, an effective patch strategy is proposed to deal with malicious worms based on social networks. A graph is formed to analyze the structure of a social network, and subgroups are formed in the graph for the distributed patch strategy. The weighted directions and activities between the nodes are taken into account to select reliable key nodes from the generated subgroups, and the Incremental PageRanking algorithm reflecting dynamic social network features (addition/deletion of users and links) is used for deriving the high influential key nodes. With the patch based on the derived key nodes, the proposed method can prevent worms from spreading over social networks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.8
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• pp.4076-4092
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• 2019

Nowadays, most users access internet through mobile applications. The common way to authenticate users through websites forms is using passwords; while they are efficient procedures, they are subject to guessed or forgotten and many other problems. Additional multi modal authentication procedures are needed to improve the security. Behavioral authentication is a way to authenticate people based on their typing behavior. It is used as a second factor authentication technique beside the passwords that will strength the authentication effectively. Keystroke dynamic rhythm is one of these behavioral authentication methods. Keystroke dynamics relies on a combination of features that are extracted and processed from typing behavior of users on the touched screen and smart mobile users. This Research presents a novel analysis in the keystroke dynamic authentication field using two features categories: timing and no timing combined features. The proposed model achieved lower error rate of false acceptance rate with 0.1%, false rejection rate with 0.8%, and equal error rate with 0.45%. A comparison in the performance measures is also given for multiple datasets collected in purpose to this research.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.3
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• pp.95-105
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• 2019

A great deal needs to be learned about why and how users participate and consume information on various online sites. The design of socio-technical systems especially for promoting engagement in terms of maximum user participation is both a theoretical and real-world challenge that researchers strive to understand. At present, most of the research on the motives of Internet video users' behavior focuses on the user's "viewing motivation" and "sharing motivation", and lacks the analysis of the factors affecting users' "subscription motivation". This study will attempt to compensate for this gap. Based on the YouTube platform, we take Chinese video users as the research object and uses the "Censydiam user motivation analysis model" to make assumptions about user subscription motivation from the two levels of social needs and personal needs, using regression analysis. Validate the hypothesis and get the influencing factors that may be available in the user's subscription motivation based on the assumptions. Built on survey data from 215 respondents, the study found that Enjoyment, Vitality, Power, and Conviviality are four factors that influence user motivation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.5
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• pp.1798-1813
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• 2021

This paper proposes a positive experience design approach for Internet of Things (IoT) intelligent products to improve users' subjective well-being in the fields of artificial intelligence and big data. First, the authors selected six target users and taking the Xiaomi IoT intelligent products for the research objects and conducted a thorough observation on how the target users used IoT intelligent products in their own homes over two weeks via a home-visiting interview, group diary, and focus group. Second, they constructed an individual activities table for the participants' IoT intelligent product experience using a hierarchical task analysis (HTA). Third, two researchers sorted out the sub-tasks of happiness in the HTA table. Finally, the authors found the positive experience design approach of IoT intelligent products. The positive experience design approach of IoT intelligent products is proposed from focusing on the personal pleasure experience to individual life meaningful design and group social relationship design, including individual pleasure experience, personal goal realization, group needs satisfaction and the harmony of group relations. The paper uses the two design examples of an interactive kettle and a harmonious chair to further discuss the feasibility of the design approach. In the era of big data, it is helpful for designers to use this design approach to improve the users' sense of sustainable pleasure, achievement perception of their future goal realization, and the well-being of the group's social relationships.

• Asia pacific journal of information systems
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• v.18 no.3
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• pp.45-65
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• 2008

The rapid growth of the Internet has increased the amount of transmission of personally identifiable information. At the same time, with new Internet related technologies, organizations are trying to collect and access more personal information than before, which in turn makes individuals concern more about their information privacy. For their successful businesses, organizations have tried to alleviate these concerns in two ways: (1) by offering privacy policies that promise certain level of privacy protection; (2) by offering benefits such as financial gains or convenience. In this paper, we interpret these actions in the context of the information processing theory of motivation. This paper follows Hann et al.(2007)'s methods to analyze Internet users privacy concerns in Korea and tries to compare the findings. Our research objectives are as follows: First, we analyze privacy concern mitigation strategies in the framework of the expectancy theory of motivation. Subsequently, we show how the expectancy theory based framework is linked o the conjoint analysis. We empirically validate the predictions that the means to mitigate privacy concerns are associated with positive valences resulting in an increase in motivational score. In order to accommodate real-life contexts, we investigate these means in trade-off situation, where an organization may only be able to offer partially complete privacy protection and/or promotions and/or convenience, While privacy protection (secondary use, improper access) are associated with positive valences, we also find that financial gains can significantly increase the individuals' motivational score of a website in Korea. One important implication of this empirical analysis is that organizations may possess means to actively manage the privacy concerns of Internet users. Our findings show that privacy policies are valued by users in Korea just as in the US or Singapore. Hence, organizations can capitalize on this, by stating their privacy policy more prominently. Also organizations would better think of strategies or means that may increase online users' willingness to provide personal information. Since financial incentives also significantly increase the individuals' motivational score of website participation, we can quantify the value of website privacy protection in terms of monetary gains. We find that Korean Internet users value the total privacy protection (protection against errors, improper access, and secondary use of personal information) as worthy as KW 25,550, which is about US 28. Having done this conjoint analysis, we next adopt cluster analysis methodology. We identify two distinct segments of Korea's internet users-privacy guardians and information sellers, and convenience seekers. The immediate implication of our study is that firms with online presence must differentiate their services to serve these distinct segments to best meet the needs of segments with differing trade-offs between money and privacy concerns. Information sellers are distinguished from privacy guardians by prior experience of information provision, To the extent that businesses cannot observe an individual's prior experience, they must use indirect methods to induce segmentation by self-selection as suggested in classic economics literature of price discrimination, Businesses could use monetary rewards to attract information sellers to provide personal information. One step forward from the societal trends that emphasize the need of legal protection of information privacy, our study wants to encourage organizations and related authorities to have the viewpoints to consider both importance of privacy protection and the necessity of information trade for the growth of e-commerce.

• Journal of Information Technology Applications and Management
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• v.21 no.4_spc
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• pp.415-429
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• 2014

With the advent of smart devices, users are able to connect to each other through the Internet without the constraints of time and space. Because the Internet has become increasingly important to users in their everyday lives, reliance on it has grown. As a result, the number of web sites constantly increases and the competition between these sites becomes more intense. Even those sites that operate successfully struggle to establish new strategies for customer retention and customer development in order to survive. Many companies use various customer information in order to establish marketing strategies based on customer group segmentation A method commonly used to determine the customer groups of individual sites is to infer customer characteristics based on the customers' demographic information. However, such information cannot sufficiently represent the real characteristics of customers. For example, users who have similar demographic characteristics could nonetheless have different interests and, therefore, different buying needs. Hence, in this study, customers' interests are first identified through an analysis of their Internet news inquiry records. This information is then integrated in order to identify each web category. The study then analyzes the possibilities for the practical use of the proposed methodology through its application to actual Internet news inquiry records and web site browsing histories.

• Information Systems Review
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• v.8 no.1
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• pp.125-139
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• 2006

Recently, as mobile internet users grow rapidly, mobile internet companies are experiencing a fierce competition to capture new customers. Under this business environment, they try to identify factors that make people use mobile internet in order to satisfy customers by providing better and diversified services. There has been enormous effort to analyze customers' behavior in choose and use mobile internet services. However, there is no one best methodology to identify factors to attract customers yet. Thus, the study applied the flow construct proposed by Csikszentmihalyi(1977) and expanded by Hoffman and Novak(1996) to identify environmental factors of internet which has impact on users' mobile internet usage. To implement the study, the following activities have been done: literature reviews on service acceptance model and flow structure, questionnaire survey, suggestion of the flow model on mobile internet, and hypothesis test. For the study, 242 out of 307 samples collected were statistically analyzed using SPSS 10.0, AMOS 4.0 statistics package. The findings of this study are as follows: First, mobile internet environment factors influencing on challenge of flow antecedent were media characteristics(use of convenience, transmission quality), contents characteristics(uniqueness, timeliness, simplicity). Second, mobile internet environment factors influencing on skill of flow antecedent were contents(uniqueness, timeliness, simplicity), charge(definiteness and diversity of charge), usage(security, instant connectivity). Third, challenge of flow antecedent had a significant effect on flow of mobile internet usage. But it was not statistically significant that skill has an influence on flow. This study discovered the relationship between mobile internet environment factors(media characteristics, contents characteristics, charge characteristics, usage characteristics) and flow experience of mobile internet users which would be a valuable insight for marketing strategies. Results shows that challenge of flow antecedent have a significant impact on flow experience in mobile internet environment. Additional, media characteristics, contents characteristics of mobile internet environment factors is positively correlated with challenge of flow antecedent. In other words, mobile internet companies should provide customers with diverse service and take a challenging attitude to get customers show aggressive attitude in mobile internet usage.