• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.6
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• pp.163-172
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• 2003

Proposed in this paper is an authentication mechanism for multimedia streaming data in the Intemet multicast environment. The multicast authentication mechanism is coupled with the packet-level forward error correction code which has been recently applied for a reliable multicast transport transmission. Associated with this, Reed-Solomon erasure code is chosen for tolerating packet loss so that each of the received packets can be authenticated independently of the lost packets.

• Journal of Family Resource Management and Policy Review
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• v.8 no.1
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• pp.61-78
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• 2004

The purpose of this study was to compare the consumers' satisfactions between those who prefer internet shopping and those who prefer CATV home shopping. This study examined both on-purchase satisfactions and post-purchase satisfactions. For on-purchase satisfactions, this study investigated informational satisfactions, convenience satisfactions, and price satisfactions, and for the post-purchase satisfactions, it examined overall satisfactions, delivery-related, and exchange or refund related satisfactions. The data(n=376) were obtained from a questionnaire. The data included 185 consumers of internet shopping, and 182 consumers of TV home shopping, and were analyzed by t-tests or chi-square test to compare those consumers' characteristics and satisfactions. The findings of this study are as follows: First, men aged 20s and those who had higher education, higher incomes were more likely to prefer internet shopping. Second, those who like TV home shopping were likely to search just one channel and to use less than 30 minutes to decide to purchase. Third, generally, those who prefer internet shopping showed higher scores of on-purchase satisfactions, and overall post-purchase satisfactions. However, TV home shopping consumers had higher scores of delivery-related satisfactions.

• The Journal of the Korea Contents Association
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• v.4 no.1
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• pp.83-89
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• 2004

Instant messaging(IM) service is one of the useful communication means in the Intemet for exchanging simple messages between users. Usually, IM service is coupled with Presence service which provides status information of users. In this case, instant messages are sent and received directly between on-line users. Therefore, messages could not be exchanged when users are in off-line state. In this paper, We have implemented SIP based Instant Messaging System which includes message server that can store and manage instant messages. With this message server, messages could be exchanged legalness of user states. Furthermore, our system includes message waiting indication event package which provides useful informations about messages in the message server. And this system also includes the Caller Preference capabilities.

• Journal of the Korean Society of School Health
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• v.20 no.2
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• pp.47-57
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• 2007

Purpose: The purpose of this study is to find out the correlation between internet addiction and school adjustment of 3rd and 4th graders in elementary schools. Methods: The subjects were 689 graders from five schools in five districts, located in G, Korea and the data were collected ficxn April 18 to May 15, 2005. A scale consisting of 25 questions were developed as an instrument for testing internet addiction and a further 25 questions were developed for examining school Adjustment. The data was analyzed by testing frequency, percentage, means, standard deviation, t-test, ANOVA, Scheffe test and Pearson's Correlation using SPSS/PC 10.0. Results: The results were as follows: The degree of internet addiction tendency were 6.0% of addiction, 24.2% of borderline and 69.8% of non-addiction. There were significant differences in school adjustment in terms of the degree of internet addiction(F=39.88, p< .05) and significant negative correlation between the degree of internet addiction and the school adjustment; the more they used to the internet, the lower school adjustment they have(r=- .376, p< .05). Conclusion: Those graders who started using the internet at an earlier age, were found to have increased levels of internet addiction. therefore, it is necessary to develop a program for the prevention of intemet addiction and a school adjustment education program is recommended for that.

• The Transactions of the Korea Information Processing Society
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• v.4 no.5
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• pp.1319-1326
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• 1997

The Internet is a very convenient neteork, but not always a So.many orvanizations often require administrative security policies when they want to connect with ther organizations thtough a pubic network.A firewall is one way of protecting an internal network from the untrusted extemal network with a mechanism for selectively permiting or blocking traffic between the intermal network and the extermal network. The firewall also provides some limited Intemet access such as Ftp.Telet, etc.Usually , through a firewall system, X applications running on the extermal network may not access an X display on the intermal network.Thus, X applications run-ning on the extemal network are not supported through the usual firewall.In this paper, we propose a method of suppoting X application programs effedtively dffectvely through the firewall, overcoming this restriction.

• The Journal of Korean Association of Computer Education
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• v.3 no.1
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• pp.135-142
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• 2000

Recently the user of distance education system using Intemet-Web are increasing rapidly. This paper shows that Hierarchical WBI documents generator by using CGI is devised and applied to development of distance education system for group-level spoken english. This overcomes the problems of the ready-made programs, which took a lot of time and cost. To generate WBI documents, The key is established to each document saved in server by types of the hierarchical structure and is transmitted to client. By client transmitting this key to server when next documentary is required. Sever can know what documents the client needs. The WBI documentary generator tells the keys transmitted from the client, automatically generates a new documentary to send, and delivery it.

• Journal of the Korean Society for Library and Information Science
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• v.35 no.3
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• pp.17-34
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• 2001

It is very important to organize materials at intemet bookstores. It is time for us to develop a subject classification scheme as a tool for increasing the effectiveness of information retrieval with ease of subject access. The purpose of this study is to examine the subject features of internet bookstores in order to suggest the effective design of the subject scheme for them. Nine internet bookstore websites are analyzed at the aspect of the subject classification of the materials. Based upon the results of this study, an effective subject classification for internet bookstores is suggested to provide a better subject access.

• Journal of Intelligence and Information Systems
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• v.9 no.3
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• pp.177-191
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• 2003

Recommender systems are a personalized information filtering technology to help customers find the products they would like to purchase. Collaborative filtering is the most successful recommendation technology. Web usage mining and clustering analysis are widely used in the recommendation field. In this paper, we propose several hybrid collaborative filtering-based recommender procedures to address the effect of web usage mining and cluster analysis. Through the experiment with real e-commerce data, it is found that collaborative filtering using web log data can perform recommendation tasks effectively, but using cluster analysis can perform efficiently.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.5
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• pp.113-127
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• 2003

WTLS as secure protocol of WAP makes TLS that is used in wireless Intemet protocol for TCP security be appropriate for wireless environments. And purpose of WTLS is to provide safe and efficient services. WTLS protocol consists of 4 protocols(Handshake, ChangeCipherSpec, Alert, Application Data etc.). In this papers we analyze properties of Handshake protocol and procedures of establishing master secret in detail. And then we analyze securities against several attacker models with them for a basis. Also we propose new Handshake protocol that is secure against active attacker model and can provide various security services.

• The Transactions of the Korea Information Processing Society
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• v.4 no.5
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• pp.1297-1307
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• 1997

This paper presents a multimedia mail system which transmit and redeive multimedia mailing messges on Intemet.This mail system is an extension of the exsting e-mail system for multimedia uncluding,text,image,MPEG video,and binary data,The MIME(Multipurpose Intert Mail Extensions)format,which is an extension of REF-822 maill format,is used to reprssent multimedia,and SMTP(Simple Mail Transfer Protocol)is utilized as a mail transport prttocol.The IMAP(Intenet Mail Access Protcol)which privides more functions than the widely used POP(Post Office Protocol)is used as a mailbox retrival protocol.The mail client is complemented on a multimedia PC while the server is implemented on a UNIX system.In the mail system, a mail sending program allows a user to attach binary files such as Postscript files and MPEG compressed video,while a receiving program provides direct interface to application programs to play back received multimedia mail messages.