• Journal of Advanced Navigation Technology
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• v.15 no.6
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• pp.939-945
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• 2011

We show a new scheme and implementation of maritime data communication systems for GMDSS ship which performs e-Navigation and removes the functional limitation of those systems through comparing to service fee, call processing reliability, and bit rates of all of those systems within communication range at sea. We confirmed available each frequency band communication and application services at sea by experimental result with proposed new system, MF/HF band being useful to a short text message service, VHF band to 9600bps email service, Fleet Broadband Maritime Satellite system to one or more Mbps multimedia service each.

• Journal of Multimedia Information System
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• v.6 no.4
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• pp.239-244
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• 2019

With the development of Cyber-Physical Systems(CPS), several technologies such as automation control, automotive and intelligent house systems have been developed. To enable communication among various components of such systems, several wired and wireless communication protocols are used. The Controller Area Network(CAN) is one of such wired communication protocols that is popularly used for communication in automobiles and other machinery in the industry. In this paper, we designed and implemented a response time analysis system for CAN communication. The reliable data transfer among various electronic components in a significant time is crucial for the smooth operation of an electric vehicle. Therefore, this system is designed to conveniently analyze the response time of various electronic components of a CAN enabled system. The priority for transmission of the messages in the CAN bus is determined by the message identifier. As the number of nodes increases the transmission of low priority messages is delayed due to the existence of higher priority messages on the bus. We used Raspberry Pi3 and PiCAN2 board to simulate the data transfer for studying the comparative delay in low priority nodes.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.2
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• pp.55-60
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• 2020

In this paper, we conducted a study on ways to not only check disaster information on smart-phone in the event of a disaster, but also simultaneously check it on wearable devices using short-range wireless communication. Wearable devices commonly used include such devices as wireless earphones, smart bands and smart-watches. Among these devices are smart-watches that allow users to view disaster information in the event of a disaster. However, because current disaster message can only check on smart-phones, research was conducted on how to deliver disaster information received from smart-phones to smart-watches. If studies such as this paper continue, we will be able to recognize disasters more efficiently in the event of a disaster and to carry out preparations for them.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.6
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• pp.1316-1322
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• 2005

Specially, though electronic commerce and electron signature technology through internet rose, PKI (Public Key Ifrastructure) is one of technologies. PKI brought several kind of new standards in encryption base technology. In spite of several kind of standardizations consist lively, shortcoming of solutions that apply PKI is expensive and slow. If main interest of encryption technology including PKI is the fast speed and security that improve, this is very serious problem. The various kinds alternatives about these problem are presented. But, we must consider about replace expense and stability etc. still. So, I propose that use suitable encryption policy by method to solve such problem. I improved some problems of existent PKI structure. Subject of this treatise designs and embody communication component could use easily and simply short message communication or simplicity way encryption communication.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.343-352
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• 2008

Safety-critical systems related to the railway communications are currently undergoing changes. Mechanical and electro-mechanical devices are being replaced by programmable electronics that are often controlled remotely via communication networks. Therefore designers and operators now not only have to contend with component failures and user errors, but also with the possibility that malicious entities are seeking to disrupt the services provided by theirs systems. Recognizing the safety-critical nature of the types of communications required in rail control operations, the communications infrastructure will be required to meet a number of safety requirements such as system faults, user errors and the robustness in the presence of malicious attackers who are willing to take determined action to interfere in the correct operation of a system. This paper discusses the safety strategies employed in the railway communications and proposes a security mechanism for Korean railway communication system. We present the developed communication safety evaluation tool based on the proposed security mechanism and also evaluate its protecting capability against the threats of masquerading, eavesdropping, and unauthorized message manipulation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.6
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• pp.3280-3298
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• 2019

Vehicular ad-hoc networks (VANETs) have become increasingly significant in intelligent transportation systems, they play a great role in improving traffic safety and efficiency. In the deployment of intelligent VANETs, intelligent vehicles can efficiently exchange important or urgent traffic information and make driving decisions. Meanwhile, secure data communication and vehicle's identity privacy have been highlighted. To cope with these security issues, in this paper, we construct an efficient anonymous authentication scheme with secure communication in intelligent VANETs. Combing the ElGamal encryption technique with a modified Schnorr signature technique, the proposed scheme provides secure anonymous authentication process for encrypted message in the vehicle-to-infrastructure communication model, and achieves identity privacy, forward security, and reply attack resistance simultaneously. Moreover, except the trusted authority (TA), any outside entity cannot trace the real identity of an intelligent vehicle. The proposed scheme is designed on an identity-based system, which can remove the costs of establishing public key infrastructure (PKI) and certificates management. Compared with existing authentication schemes, the proposed scheme is much more practical in intelligent VANETs.

• Journal of the Korea Society of Computer and Information
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• v.24 no.1
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• pp.265-271
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• 2019

In this paper, the Software Education program for elementary school students in Multicultural families developed so that Multicultural students can adapt to national, school, peer, and teacher. The effects of Resilience, Communication skills and Interpersonal Relationshiop were investigated. The developed Software education program was designed in such a way that the target students became more intimate with each other and adapted to Korean culture, peers, and teachers through the analysis of the research subjects. Resilience test showed statistically significant difference in peer relationship and support, family support and interaction, teacher's interest and support, self - identity, and cultural acceptance. Communication ability test showed statistically significant differences in interpretation ability, self presentation ability, goal setting ability, and message conversion ability. The interpersonal Relationship test showed statistically significant differences in people's orientation toward people, facing people, and away from people. The results of this study indicate that the software education program for elementary school students in multicultural families has effects on adaptive flexibility, communication ability, and interpersonal ability. In the future, There is a need for continuous research with development and effectiveness of various software education programs for Multicultural students.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.6 no.1
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• pp.130-140
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• 1999

This study was designated to investigate communication barriers of nurses in clinical settings. This study was done in 2 phases, first content analysis on descriptions of 50 nurses in three general hospitals and 40 nursing students on communication barriers for nurses in clinical settings, and second a survey to investigate the factors related to communication barriers and the relation between the nurse's characteristics and the extent of communication barriers in clinical settings from two nurses educators, 13 nursing students who experienced clinical practice and 71 nurses in 11 general hospitals. The results are as follows : 1. Through content analysis, 11 properties of communication barriers for nurses in clinical settings were identified. These were inappropriate communication style as a nurse, lack of professionalism, in appropriate control of emotions, lack of knowledge about the clincal setting, the lack of preparation about content of communication, the problem in trust relation, differences in priorities in needs, uncontroleable situation for nurses, inappropriate nurses' perception about patients, conflict with medical team and inadequate systematic support were identified and grouped in to four categories, communicator, message, feed-back and communication context. 2. The four factors in communication barriers for nurses in the clinical setting were identified and named as ambiguity in the nurses' position, lack of confidence, difference in perspectives with patients and in-adequate nurse-patient relationship. 3. There was a significant difference(F=5.31, P=0.0022, F=3.62, P=0.0316, F=2.80, P=0.067, F=9.01, P=0.0003) among the groups according to work place in rating the extent of the communication barrier in the clinical setting and in the four factors, the nurses working in the psychiatric patient unit rated the communication barrier in the clinical setting lowest among the groups. There was a significant negative correlation between the length of the nurses's carrier and the extent of communication barrier in three factors, ambiguity in the nurses' position, lack of confidence and inadequate nurse-patient relationship.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.11
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• pp.545-561
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• 2007

Location management and message delivery protocol is fundamental to the further development of mobile agent systems in a multi-region mobile agent computing environment in order to control mobile agents and guarantee message delivery between them. However, previous works have some problems when they are applied to a multi-region mobile agent computing environment. First, the cost of location management and message delivery is increased relatively. Second, a tracking problem arises. finally, cloned mobile agents and parent-child mobile agents do not get dealt with respect to location management and message delivery. In this paper, we present a HB (Home-Blackboard) protocol, which is a new location management and message delivery protocol in a multi-region mobile agent computing environment. The HB protocol places a region server in each region and manages the location of mobile agents by using intra-region migration and inter-region migration. It also places a blackboard in each region server and delivers messages to mobile agents when a region server receives location update form them. The HB protocol can decrease the cost of location update and message passing and solve the tracking problem with low communication cost. Also, this protocol deals with the location management and message passing of cloned mobile agents and parent-child mobile agents, so that it can guarantee message delivery of these mobile agents and pass messages without passing duplicate messages.

• Journal of Korea Multimedia Society
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• v.23 no.7
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• pp.819-829
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• 2020

Underwater communication is necessarily useful for various application domains such as saving of human lives from underwater disasters, marine resource exploration, underwater military fields, underwater environment or ecosystem monitoring, fish farm monitoring and management, etc. Even though the acoustic wave has been the main underwater communication media until now, several media such as optical waves, VLF/ELF waves, magnetic fields, and infrared rays also began to be treated as possible media for underwater communication. If these underwater communicate-possible media are used mixing together, the underwater communication can be much more reliable and efficient through complementing the disadvantages of each communication media with advantages of other communication media. In fact, mixing and using multi-media for underwater communication requires the data flow control in the connection process of different media due to their communication speed gaps and bandwidth differences, and, specially, in the flow control, the appropriate message fragmentation technique is required inevitably. For this reason, this paper presents a fragmentation framework and technique necessary to the flow control in the underwater multi-media communication. In addition, through its implementation and experiments, this paper shows the feasibility on the realization of the multi-media based underwater communication.