• TTA REPORT
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• v.5 no.3 s.19
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• pp.22-26
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• 1993

ITU에서는 매년 5월 17일 ''세계전기통신의 날''로 정하여 해마다 특정 주제를 갖고 이를 기념하도록 권장하고 있다. 이에따라 협회는 제3회 ITU교육 프로그램을 개최하여 경제적, 사회적, 문화적 발전에서 전기통신의 중요성을 공동으로 인식하고 전기통신에 대한 관심 증진 및 국제협력에 대한 인식의 제고와 ITU국내 연구단 활동의 격려 및 홍보를 도모하고자 하였다. 이날 교육프로그램은 ITU사무총장의 메시지 및 슬라이드 시청을 시작으로 한국통신 개발연구원의 김은주 박사를 초청하여 ITU 조직과 활동에 대한 강연회를 개최하였으며, TTA$\cdot$ITU-RS(구 CCIR)$\cdot$ITU-TS(구 CCITT)의 조직과 활동사항에 관해 협회 각 담당자의 발표가 있었다. 이에 제128주년 세계 전기통신의 날(World Telecommunication Day)을 맞이하여 ITU사무총장이 전세계 177개 ITU회원국에게 보낸 메시지 전문을 소개하고자 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.12
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• pp.1195-1207
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• 2012

Fast and reliable message broadcasting is critical for safety critical applications of VANET due to the urgency and/or significance of the messages for passengers and drivers. For reliable message delivery, a mechanism for checking the reception of message at the neighboring vehicles and retransmitting it if necessary is required. Especially, in urban environments, where the traffic density tends to be high, mechanisms that minimize control message overhead such as beacon are appropriate in order to minimize the message collisions. Furthermore, broadcast delivery is especially difficult at the intersection due to the road side obstacles such buildings, and hence, a mechanism that enables effective and efficient delivery across intersections is required. In this paper, we propose a beaconless reliable and efficient broadcast approach which specifically taking into account the urban streets. The proposed approach checks the message reception of neighboring vehicles implicitly by taking into account the broadcast of message by next vehicle as the acknowledgement. When retransmissions is necessary around the intersections, vehicles located within the intersection area, where the chance of successful signal propagation toward every branch of the intersection is higher due to less signal attenuation caused by road side obstacles, are to do the retransmissions. Simulation results show that the proposed approach can provide better reliability while consume less resources than the existing approaches.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.5
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• pp.518-528
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• 2000

Messages in distributed real-time systems are categorized into two groups: synchronous messages and asynchronous messages. Synchronous messages, such as sampled audio and image data,are generated periodically with delivery time constraints. Protocols should guarantee the end-to-enddeadlines for such messages. Asynchronous messages are non-periodic and may arrive in a randomway with no strict time constraints.In this paper, we propose TTP/C(timed token protocol with concession), an extension of TTPprotocol, to achieve higher timeliness guarantee for synchronous messages in distributed real-timesystems. In TTP/C, a node concedes the allocated bandwidth to other nodes with urgent synchronousmessages to be sent provided that the node has no urgent messages, TTP/C works very well evenif the synchronous messages are generated with some jittering by nodes. The simulation results showthe improved performance of TTP/C protocol for guaranteeing synchronous messages deadlinescomeared to the existing TTP protocols.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.3B
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• pp.149-157
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• 2012

In WSN environment, the sensor nodes collect sensed data, and transmit data to the BS. BS is difficult to trust the data from unauthenticated nodes. Therefore, many papers have been proposed about the node authentication and the safety of data. In the AM-E paper, data is delivered after node authentication. In this time, the sensor nodes are directly communicated to BS the AREQ/AREP message for authentication. Therefore, the sensor nodes consume more energy for authentication. Also, noes communicate directly with the BS for authentication will have problem due to the limited energy of nodes. In this paper, the same security with AM-E is supported, Furthermore, to minimize the energy consumption, IDE based hierarchical node authentication protocol is proposed. Compared with AM-E, the number of alive nodes is increased about 39%. Thus, the entire network life time is extended and energy efficiency is improved.

• Journal of Convergence for Information Technology
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• v.11 no.7
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• pp.21-30
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• 2021

With the development of IoT technology, various cloud computing-based services such as smart cars, smart healthcare, smart homes, and smart farms are expanding. With the advent of a new environment, various problems continue to occur, such as the possibility of exposure of important information such as personal information or company secrets, financial damage cases due to hacking, and human casualties due to malicious attack techniques. In this paper, we propose a message communication protocol for smart home-based secure communication and user data protection. As a detailed process, secure device registration, message authentication protocol, and renewal protocol were newly designed in the smart home environment. By referring to the security requirements related to the smart home service, the stability of the representative attack technique was verified, and as a result of performing a comparative analysis of the performance, the efficiency of about 50% in the communication aspect and 25% in the signature verification aspect was confirmed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.5
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• pp.979-985
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• 2016

In this paper, a distributed instant message system with multiple servers architecture which can distribute system load effectively using an extended media control channel has been presented. A media control channel provides establishing a reliable control channel and also keeping a reliable control channel between SIP server and client in the field of real-time media transport area. In this study, a new instant message system architecture which can distribute massive instant message including multimedia data to multiple servers has been presented. The presented instant message system architecture can distribute system load by extending media control channel. For this purpose, media control channel messages, which distribute system load to multiple servers dynamically according to increasing number of users, have been designed in our presented system. And, in our research, an exchanging procedures of media control channel messages between servers have also been presented. The performance of the proposed system has been analysed by simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.4
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• pp.777-785
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• 2016

IM(Instant Messenger) chatting service can carry user's various information including life style, geographical position, and psychology & crime history and thus forensic analysis on the IM service is desirable. But, forensic analysis for KakaoTalk's chatting service is not well studied yet. For this reason, we study KakaoTalk's forensic analysis focusing on chatting service. This paper first details a general method of IM forensics investigating the previous articles about IM forensics although there are not many articles. Second, we discuss methodologies for IM forensics wherein we present analysis of table structure and method for reconstruction of chatting message. These result in the basic element of forensic tools of KakaoTalk chatting message. Last, we compare artifacts of KakaoTalk with that of WhatsApp. We conclude that these applications are, at least, different in that table structures and the ways to reconstruct chatting messages are not same and therefore digital evidences or artifacts are not same and somewhat distinct.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.11
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• pp.1004-1013
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• 2012

The legacy voice broadcast systems are used to broadcast the voice over an entire space or a specific zone. these broadcast systems generate unnecessary noise and waste of resources. In this paper, we propose a ubiquitous voice message broadcast system called uPaging, by combining the technique of location-awareness and the voice message delivery service in ubiquitous sensor network environment. In uPaging system, the wire/wireless hybrid network is used to implement the network system. Also, in order to actualize the location-awareness service, we use the Bidirectional Location ID-Exchange protocol was suggested by our previous research. the uPaging system can deliver the voice to a selected user or the location in which the user is present by this location awareness.

• Journal of KIISE:Information Networking
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• v.34 no.6
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• pp.423-434
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• 2007

Vehicular ad-hoc network (VANET), a kind of mobile ad-hoc network (MANET), is a key technology for building intelligent transportation system (ITS). VANET is automatically and temporarily established through vehicle-to-vehicle communication without network infrastructure. It has the characteristics that frequent changes of network topology and node density are occurred and messages are disseminated through several relay nodes in the network. Due to frequent change of network topology and node density, however, VANET requires an effective relay node selection scheme to disseminate messages through the multi-hop broadcast. In this paper, we propose a contention window based multi-hop broadcast scheme for VANET. Each node has an optimized contention window and competes with each other for a relay node. The experimental results show that the proposed scheme has a better performance than the distance-based deterministic broadcast scheme in terms of message propagation delay and network traffic.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.3
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• pp.93-106
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• 1999

In this paper, the basic architecture of an agent system was designed and a KQML(Knowledge Query and Manipulation Language) handler was implemented to handle 'tell', 'ask', 'handles' and 'interested' KQML performatives. The basic architecture of an agent system consists of a KQML handler, a KIF interpreter and a Flow control code. Agents use KIF(Knowledge Interchange Format) to represent the actual knowledges that are transmitted. They communicate others via an external language called KQML, which contains contents of messages written in KIF. The KQML handler controls communication. Contents of messages through it are stored and interpreted by the KIF interpreter. The flow control code controls the flow of program and information and performs engineering tasks. It gets knowledges from the knowledge base of the KIF interpreter and the other agents.