• Journal of Korea Multimedia Society
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• v.21 no.12
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• pp.1448-1458
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• 2018

Vehicular Ad-Hoc Networks (VANETs) have become one of the active areas of research, standardization, and development because they have tremendous potentials to improve vehicle and road safety, traffic efficiency, and convenience as well as comfort to both drivers and passengers. However, message trustfulness is a challenge because the propagation of false message by malicious vehicles induces unreliable and ineffectiveness of VANETs, Therefore, we need a reliable reputation method to ensure message trustfulness. In this paper, we consider a vulnerability against the Sybil attack of the previous reputation systems based on blockchain and suggest a new reputation system which resists against Sybil attack on the previous system. We propose an initial authentication process as a countermeasure against a Sybil attack and provide a reliable reputation with a cooperative message delivery to cope with message omission. In addition, we use Homomorphic Commitment to protect the privacy breaches in VANETs environment.

• Journal of muscle and joint health
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• v.21 no.1
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• pp.19-26
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• 2014

Purpose: This study was examined the effects of a hepatitis A education on attitude, vaccination intention, and preventive behavior. Methods: Eighty-eight college students at two universities participated in this study. The data were collected from August 29 to September 30 in 2011 and were analyzed using descriptive statistics, t-test, and ${\chi}^2$ test. Results: There were no significant differences of preventive behavior of hepatitis A between the positive and negative message groups (t=1.10, p=.499). However, the negative message group had a significantly higher attitude of preventive behavior (t=0.92, p=.049) and vaccination intention (${\chi}^2$=5.43, p=.039) than the positive message group. Conclusion: This study demonstrates that negatively framed messages are effective on increasing the attitude, vaccination intention, and preventive behavior.

• Journal of the Korean Society of Food Culture
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• v.21 no.5
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• pp.536-540
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• 2006

The purposes of this study were 1) to analyze the correlation between Word-of-Mouth(WOM) message sender credibility and WOM effect and 2) to analyze the differences of WOM message sender creadibility and WOM effect in off-line and on-line WOM communication. The messages were created as a form of scenario for this study. Respondents were asked to evaluate the message sender credibility and predict WOM behaviors after reading given scenario. The questionnaires were distributed to 200 customers and a total of 175 questionnaires were used for analysis(87.5%). The statistical analysis was conducted using SPSS Win(12.0) for descriptive analysis, paired t-test, factor analysis, correlation analysis. The positive off-line WOM message sender was considered as more credible(p<.001) than on-line WOM message sender. 'Message sender credibility' is correlated with 'attitude formation' in both channels, but 'reliable' factor of 'credibility' variable is not significantly correlated with 'attitude change'.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.604-621
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• 2021

Examination of the concurrent evolution of communication tools and eating behaviors over recent decades reveals that social media and other forms of digital content have become powerful new driving forces for nutritional choices and food consumption. The purpose of this research was to examine the effect between goal orientation of message (promotion versus prevention) and the type of message (text versus image) on effectiveness of the message. The findings showed that individuals exposed to a promotion-focused message similarly responded to the message regardless of the type of the message. By contrast, those who exposed to a prevention-focused message showed significantly more positive responses to the message posted on the text-based social media than the message on the image-based social media. The findings indicated that, if presented effectively, social media could be harnessed to promote healthier eating habits and behaviors, prevent those which can be harmful, and ultimately improve an individual's daily food consumption and overall quality of life.

• Proceedings of the CALSEC Conference
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• 2001.02a
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• pp.427-444
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• 2001

ㆍ ebXML Message Services Requirements Specification - Working Draft 26-May-2000, v0.96 · ebXML Message Services Specification - Working Draft 13-Sep-2000, v0.21 ㆍ ebXML Collaboration Protocol Profile and Agreement Specification - Working Draft 24-Jan-2001, v0.29 · ebXML Technical Architecture Security Specification - Working Draft 5-Feb-2001, vl.02(Under development) ㆍ ebXML Message Service Interface Specification - Under development.(omitted)

• Journal of the Korea Society of Computer and Information
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• v.21 no.5
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• pp.57-64
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• 2016

In this paper, we propose the design of railway safety common data model to provide common transformation method for collecting data from railway facility fields to Real-time railway safety monitoring and control system. This common data model is divided into five abstract sub-models according to the characteristics of data such as 'StateInfoMessage', 'ControlMessage', 'RequestMessage', 'ResponseMessage' and 'ExtendedXXXMessage'. This kind of model structure allows diverse heterogeneous data acquisitions and its common conversion method to DDS (Data Distribution Service) format to share data to the sub-systems of Real-time railway safety monitoring and control system. This paper contains the design of common data model and its DDS Topic expression for DDS communication, and presents two kinds of data transformation case studied for verification of the model design.

• Journal of the Korea Society of Computer and Information
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• v.21 no.4
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• pp.17-24
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• 2016

In this paper, we propose a AH LSU(Advanced Hybrid QoS Routing Link State Update) Algorithm that improves the performance of Hybrid LSU(Hybrid QoS Link State State Update) Algorithm with statistical information of flow holding time in network. AH LSU algorithm has had both advantages of LSU message control in periodic QoS routing LSU algorithm and QoS routing performance in adaptive LSU algorithm. It has the mechanism that calculate LSU message transmission priority using the flow of statistical request bandwidth and available bandwidth and include MLMR(Meaningless LSU Message Removal) mechanism. MLMR mechanism can remove the meaningless LSU message generating repeatedly in short time. We have evaluated the performance of the MLMR mechanism, the proposed algorithm and the existing algorithms on MCI simulation network. We use the performance metric as the QoS routing blocking rate and the mean update rate per link, it thus appears that we have verified the performance of this algorithm.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.5
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• pp.113-120
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• 2013

This paper presents a mathematical model to determine the optimal length of static messages that can achieve more efficient use of a FlexRay network. In order to determine the optimal length of static message, the proposed model evaluates the given set of messages with respect to a network utilization index, which is defined in this work. The efficient use of a FlexRay network is achieved by reallocating any static message whose length is equal or greater than the resulting value to the dynamic segment. The effectiveness of the proposed method is investigated by applying to the SAE benchmark data.

• Journal of the Korea Society of Computer and Information
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• v.21 no.9
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• pp.57-63
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• 2016

The purpose of the study is to investigate the preference by emoticon types according to the gender of sender, emotion types of message and intimacy with the recipient. Results show that women mostly prefer to use dynamic and imaged emoticon than men. However, the preference of using text messages increases when both men and women express uncomfortable emotion. Especially, when users send family messages, they tend to prefer for text message. And when users send close friends messages, the preference for dynamic and imaged emoticon is high. When users send distant friends messages, the similar tendency is shown regardless of emotion. These results can provide the information to use emoticon in the filed of education and take advantage in digital education and mobile education.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.3
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• pp.568-577
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• 2017

IEEE Std 1609.2 was defined for the support of communication security functions in the WAVE (Wireless Access in Vehicular Environments) system. IEEE Std 1609.2 defined the message structures of the security services and managements on the vehicular communication by using ASN.1 (Abstract Syntax Notation One). Also, this security message structures shall be encoded using the COER (Canonical Octet Encoding Rules). In this paper, we designed and implemented the IEEE Std 1609.2 message encoder/decoder handling the security messages defined in IEEE Std 1609.2. The designed encoder/decoder consists of three modules as follows : a module generating the message of C language data structures in accord with IEEE Std 1609.2 message structures, a message encoder module, a message decoder module. And the encoder/decoder was implemented on the Linux environment. Also we analyzed the performance by measuring the performance speed of the encoder/decoder implemented.