• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.8B
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• pp.768-776
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• 2009

This paper analyses the message complexity of TDMA ad hoc MAC protocols. Since the network resource of ad hoc networks is limited due to the multiple interferences and the contention-based wireless channel, the scalability issue is one of the main research topics in developing ad hoc algorithms. Simulation demonstrates that SMACS protocol has the lowest message complexity, whereas TMMAC has the highest. In addition, it is found that since the effect of unicast dominates in the message complexity compared to other factors with an increasing number of nodes, Z-MAC tends to have the property of linearity, whereas BMA and TMMAC show exponential increases in their complexities.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.8
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• pp.1855-1860
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• 2010

This paper describes construction of web services system for secure message transmission appling web services standards. This system composes single sign on module, SSL module and secure message module. We applied these modules to price comparison site. Single sign on module used SAML standards. This module was designed, in order to provide authentication and authorization. As SSL module processes message encryption among end to end, messages of this system are secure. Secure message module is designed according to WS-Security standards and processes authentication, XML signature and XML encryption.

• The Transactions of the Korea Information Processing Society
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• v.6 no.2
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• pp.476-484
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• 1999

Many message logging and checkpointing schemes are proposed for fault tolerance in distributed systems in which nodes communicate by message passing. Most researches for recoverable distributed shared memory (DSM) also adopt similar schemes used in message passing systems. However, schemes used in message passing systems are not always appropriate to be directly used in DSM systems because the two systems, message passing systems and DSM systems, have different natures (function shipping and data shipping). Many modified schemes have been proposed for DSM systems to resolve these differences. In this paper, an object oriented approach is proposed for recoverable DSM. We present a new dependency tracking scheme between pages instead of processes. Based on this scheme, we propose new checkpointing and recovery schemes that can reduce overhead to make DSM recoverable.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.9
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• pp.3421-3443
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• 2021

A data hiding method based on integer factorization via e-books in the EPUB format with XHTML and CSS files for copyright protection is proposed. Firstly, a fixed number m of leading bits in a message are transformed into an integer which is then factorized to yield k results. One of the k factorizations is chosen according to the decimal value of a number n of the subsequent message bits with n being decided as the binary logarithm of k. Next, the chosen factorization, denoted as a × b, is utilized to create a combined use of the

and elements in the XHTML files to embed the m + n message bits by including into the two elements a class selector named according to the value of a as well as a text segment with b characters. The class selector is created by the use of a CSS pseudo-element. The resulting web pages are of no visual difference from the original, achieving a steganographic effect. The security of the embedded message is also considered by randomizing the message bits before they are embedded. Good experimental results and comparisons with exiting methods show the feasibility of the proposed method for copyright protection of e-books.

• The Research Journal of the Costume Culture
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• v.17 no.5
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• pp.791-806
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• 2009

Internet brand community's message makes significant contributions for fashion industry. Therefore, if we understand and implement the characteristics of the message on the Internet brand's community, it can be useful for future marketing strategy. This study was to classified the internet community and to examine messages with regard to direction, write motive and prior knowledge. The messages were taken from February, 20th, to August, 7th in 2008. Content analysis method was used for this study. The results were as follows: First, Fashion brand community divided into user initiative type and enterprise establishing type. Second, User initiative type had positive direction message more than enterprise establishing type had. Third, User initiative type had large volumes of information searching or sharing related message, but enterprise establishing type had large quantities of personal experience related message about write motive. Fourth, There was no difference numerical prior knowledge between user initiative type and enterprise establishing type, and then both had a high rate of prior knowledge.

• 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 Information Technology Applications and Management
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• v.23 no.1
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• pp.97-117
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• 2016

Drawing on the theoretical framework of customer value-satisfaction-loyalty, this study examines how scarcity message influences customers' value, satisfaction, and loyalty in the context of group-buying social commerce. Previous studies have argued that scarcity message limiting the avilability of products and service is a source of enhancing customer value. In this regard, this study posits scarcity message as a predictor of customer value. Furthermore, this study classifies customer value into two forms (i.e., utilitarian value and hedonic value) and verfies how scarcity message is associated with them. To test the proposed research model and hypotheses, this study performed structural equation modeling (SEM) analyses, using a total of 292 data collected on users who have experience in purchasing products and service through group-buying social commerce sites such as Coupang, Timon, and WeMakePrice. The key results are as follows : First, scarcity message increases utilitarian and hedonic values and further customer satisfaction. Second, utilitarian value increases customer satisfaction and repurchase intention while hedonic value has nothing to do with them. The findings imply that customers seek to maximize utilitarian value through group-buying social commerce. Finally, this study indicates that repuchase intention depends greatly on customer satisfaction.

• Journal of KIISE
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• v.42 no.7
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• pp.939-945
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• 2015

From 2009, the market of smart devices has been rapidly increasing. These devices provide various services to users. The cloud messaging service, especially, is applied to many various services, and sends messages asynchronously. In the cloud messaging service, there are two methods for message transmission, message transmission based on an IP address and a publish/subscribe technique. Each technique uses basic messages in order to send messages to mobile devices. In this paper, the hybrid message transmission, based on user-customized analysis to reduce basic messages, is proposed. The hybrid message transmission uses Exponential Moving Average (EMA) and K-means algorithms for user-customized analysis, and determines the message transmission techniques in each timeslot.

• Annual Conference of KIPS
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• 2009.11a
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• pp.673-674
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• 2009

전자신분증 시스템을 구현하기 위해서는 여러 가지 보안요소들이 고려되어야 한다. 본 논문에서는 Hash Tree와 Keyed Hash를 이용하여 전자신분증 시스템에 효율적으로 적용될 수 있는 메시지 인증(Message Authentication) 프토토콜을 제안한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.10
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• pp.2223-2229
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• 2010

The integrity monitoring of anomalous GPS signal have been researched because of the degradation of GPS satellite performance. It is known that anomalous GPS signal can occur by failure of GPS satellite, sudden increase of ionosphere delay error, SA, wrong modeling for navigation parameters from control segment, and an electromagnetic wave interference, etc. In case of GPS anomaly by satellites can arise from carrier frequency, code and navigation message. In this paper, the scenarios with navigation message errors were made by using GPS simulator, and the influences of GPS navigation message error to receiver were analysed. The anomalies of preamble, bits related TOW count message, subframe ID in HOW, bits related satellite healthy, and the other navigation message errors were described and simulated. Also, the number of satellites, DOP and pseudorange are analyzed to know how the anomalous signal can affect on GPS receiver.