• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.3
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• pp.43-53
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• 2007

Internet becomes more and more popular, and most companies and institutes use web services for e-business and many other purposes. With the explosion of Internet, the occurrence of cyber terrorism has grown very rapidly. Simulation is one of the most widely used method to study internet worms. But, it is quite challenging to simulate very large-scale worm attacks because of various reasons. In this paper, we propose a hybrid modeling method for RCS(Random Constant Spreading) worm simulation. The proposed hybrid model simulates worm attacks by synchronizing modeling network and packet network. So, this model will be both detailed enough to generate realistic packet traffic, and efficient enough to model a worm spreading through the Internet. Moreover, our model have the capability of dynamic updates of the modeling parameters. Finally, we simulate the hybrid model with the CodeRed worm to show validity of our proposed model for RCS worm simulation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.10
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• pp.1712-1732
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• 2011

Cloud provides dynamically scalable virtualized computing resources as a service over the Internet. To achieve higher resource utilization over virtualization technology, an optimized strategy that deploys virtual machines on physical machines is needed. That is, the total number of active physical host nodes should be dynamically changed to correspond to their resource usage rate, thereby maintaining optimum utilization of physical machines. In this paper, we propose a pattern-based prediction model for resource provisioning which facilitates best possible resource preparation by analyzing the resource utilization and deriving resource usage patterns. The focus of our work is on predicting future resource requests by optimized dynamic resource management strategy that is applied to a virtualized data center in a Cloud computing environment. To this end, we build a prediction model that is based on user request patterns and make a prediction of system behavior for the near future. As a result, this model can save time for predicting the needed resource amount and reduce the possibility of resource overuse. In addition, we studied the performance of our proposed model comparing with conventional resource provisioning models under various Cloud execution conditions. The experimental results showed that our pattern-based prediction model gives significant benefits over conventional models.

• Journal of the Korean Society of School Health
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• v.25 no.2
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• pp.214-221
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• 2012

Purpose: This study was to assess the association of internet addiction and depression, stress and suicidal ideation among adolescents. Methods: The authors have surveyed 2 middle schools and 2 high schools located in Seoul and analyzed 525 questionnaires. The questionnaire included the Internet Addiction Self Diagnosis Index (K-index), Child Depression Index (CDI), Stress Index and Reynold's Suicidal Ideation Index. Structural equational model analysis was done to explore the association between internet addiction and suicidal ideation. Results: The adolescent internet addiction groups were classified as the high risk group 12 (2.3%), the potential risk group 64 (12.2%) and the normal group 449 (85.5%). When classified according to sex, the high risk group is consisted of 8 (3.9%) boys, 4 (1.3%) girls and the potential risk group is consisted of 41 (64.1%) boys and 23 (35.9%) girls which leads to the conclusion that boys are relatively more addicted compared with girls. The group with more addiction showed higher depression scores, stress scores and suicidal ideation scores. The correlation analysis showed the significant relations between internet addiction and depression (r=0.263), stress (r=0.265) and suicidal ideation (r=0.284). According to the structural equation model analysis, internet addiction had direct effects on the depression and indirect effects on suicidal ideation. Stress had the significant direct effects on both internet addiction and depression. Depression had a significant direct effect on suicidal ideation. Conclusion: Internet addiction affects directly and indirectly an depression and suicidal ideation among adolescent.

• The Research Journal of the Costume Culture
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• v.20 no.4
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• pp.573-593
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• 2012

The purpose of this study was to investigate consumers' buying intention toward fashion goods through global internet shopping malls. This research employed Technology Acceptance Model (TAM) as a theoretical framework and was extended to introduce fashion innovativeness, clothing involvement, consumers' needs for uniqueness, computer self-efficacy as external factors. A total of 381 copies of questionnaires were collected online. The subjects of this study were women. The collected date were analysed by factor analysis, Cronbach's alpha, correlation and path analysis. The results indicated that fashion innovativeness, clothing involvement and consumers' needs for uniqueness had a significant positive affect on perceived usefulness. Consumers' needs for uniqueness and computer self-efficacy had a significant positive affect on perceived ease of use. Perceived usefulness and perceived ease of use were found to influence buying intention toward fashion goods through global internet shopping malls. The results of this study also suggested that perceived ease of use was actually a causal antecedent to perceived usefulness. This study reveled that employing TAM to investigate the buying intention toward fashion goods through global internet shopping malls was appropriate. This study also provides empirical analysis that can serve as a guide for marketers of the fashion industry in activating global internet shopping malls.

• Korean Journal of Human Ecology
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• v.10 no.1
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• pp.83-91
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• 2001

Currently, obtaining information about the housing studies through the internet web sites is one of the outstanding mediums. Those are of the housings, architecture, interior design, furniture products, hotels and its journals, etc., and out of all those informations are the highly expected value of use. But. it may causes the public users to experience a negative effect, because many of those informations provided on the internet web sites related to the housing studies/informations are not providing an equal quality of information. And measuring the quality is also not easy. This study focuses on the establishment of evaluation criterion for the housing information-related internet web sites. In such a vein, it proposes a clear model to evaluate the information qualities with the 43 questionnaires / examining items. To test the questionnaires/rating items, the analysis has been implemented which has shown the reciprocal effect between the 2 major factors. One major factor with 4 variables on the information searches are (1) the accuracy/reliability of contents and techniques, (2) the design of a picture and communication, (3) the readability and security, and (4) the security of private information, and the other factor with 3variables on the additional services are (1) the diversities of contents and ease of orderings, (2) the abilities of search and e-mail, and (3) the events and after services. This study/rating model will provide the users with a fundamental material in evaluating the quality of housing information on the internet web sites.

• Korean Management Science Review
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• v.22 no.1
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• pp.27-46
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• 2005

As the electronic commerce has grown dramatically, visiting the Internet shopping malls is accepted as one of our daily life. Despite many studies about user acceptance of the Internet shopping malls, it still remains unanswered how the Internet shopping mall's three quality factors such as system qualify, Information qualify, and service quality affect user trust, and eventually user acceptance of the mall. To investigate this issue, we propose a research model in which six external factors such as three qualify factors as well as self-efficacy, subjective norm, and trust have a significant impact on user's attitude and intention to use the mall. After garnering 244 valid questionnaires from users, we analyze them with structural equation modeling. Experiment results show that the Internet shopping mall's three quality factors such as system quality, information qualify, and service quality significantly Influence user trust for the mall, which in turn impacts user's perceived usefulness, attitude toward using the mall. Another external factors such as self-efficacy and subjective norm also influence user's perceived ease of use and perceived usefulness respectively, affecting user's attitude altogether. Implications and further research directions are presented.

• The Research Journal of the Costume Culture
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• v.23 no.5
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• pp.876-893
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• 2015

The purpose of this study is to identify the influences of psychological variables and fashion-related psychological variables on purchasing fashion items on the Internet. Boredom proneness and public self-consciousness were selected as psychological variables, and dressing style was selected as a fashion-related psychological variable. It was hypothesized that boredom proneness and public self-consciousness not only influence the purchasing frequency of fashion items on the Internet directly, but also indirectly through dressing style. Data were gathered by surveying university students in Seoul using convenience sampling. Two hundred and eighty-six questionnaires were used in the statistical analysis. SPSS was used for exploratory factor analysis, and AMOS was used for hypothesized relationship testing. The factor analysis of boredom proneness revealed five dimensions, "helplessness," "affective response," "lack of internal stimulation," "lack of external stimulation," and "perception of time." The factor analysis of public self-consciousness revealed two dimensions, "appearance-consciousness" and "style-consciousness," and the factor analysis of dressing style revealed one dimension. The overall fit of the hypothesized model suggests that the model fits the data well. The hypothesized relationship test proved that boredom proneness and public self-consciousness influence the purchasing frequency of fashion items on the Internet indirectly through dressing style. The results implicate effective strategies for Internet shopping malls and suggestions for future study.

• Journal of the Korean Home Economics Association
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• v.40 no.5
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• pp.179-193
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• 2002

This study aims to examine the forming procedure of consumer satisfaction from Internet shopping experience. Many studies on the satisfaction have primarily focused on the examination of the antecedents of satisfaction along with the expectation-disconfirmation paradigm dominating the former studies. This study has built an Internet shopping expectation-disconfirmation model as to apply the expectation-disconfirmation into the condition of the Internet shopping. The summary of study represented in following. l. The expectation of risk and performance of benefit had a significantly positive effect on the perceived disconfirmation. In addition, an expectation of benefit and performance of risk had a significantly negative effect on the perceived disconfirmation. 2. A performance of risk and performance of benefit not only had a significantly indirect effect, but also a significantly direct effect on the consumer satisfaction. But expectation of risk and expectation of benefit had no significant direct effect on satisfaction. 3. Not only the perceived disconfirmation had a significant positive effect on satisfaction, but also an effect of the perceived disconfirmation on satisfaction(0.472) is larger than that of the performance of risk or performance of benefit. Meaning that, it is desirable for one to apply the expectation-disconfirmation model into the Internet shopping circumstances as much as the off-line markets.

• The KIPS Transactions:PartC
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• v.12C no.6 s.102
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• pp.839-846
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• 2005

Recently broadband convergence network technology is emerging as an integrated network of telecommunication, broadcasting and Internet. But there are various threats as side effects against the growth of information technology, and malicious codes such af Internet worms may bring about confusions to upset a national backbone network. In this paper, we survey the traditional spreading models and propose a new worm spreading model on Internet environment. We also analyze the spreading effects due to tile spread period and the response period of Internet worms. The proposed model leads to a better prediction of the scale and speed of worm spreading. It can be applied to high-speed network such as broadband convergence network.

• The Journal of the Korea Contents Association
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• v.5 no.6
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• pp.65-73
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• 2005

Request about fast diffusion of internet and high-capacity multimedia service is increasing day after day. Because existent wireless LAN is short range, if subscriber is far away in base station transceiver system(Base Station), subscriber's quality of service becomes low, and wileless internet is expensive. Lately, WiBro(Wireless Broadband Internet) system that is developed in domestic by world first, is high-speed portable internet service that is situated in middle area of mobile phone and wireless LAN. In this paper, service traffic model and characteristics are analyzed to provide multimedia service based on IEEE 802.16 BWA accomplishes base of WiBro and simulation is conducted according to various traffic mixing ratio. Finally, on the basis of these simulation results, maximum allowable number of subscriber per cell is calculated.