• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.907-909
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• 2016

In this peper, we proposed efficient network structure using UAV squad in DTN. In Delay Tolerant Network(DTN), the routing protocols adopting store-carry-forward method are used for solving network problem occurred by the unstable network environments. This routing method is useful for work in disaster and battle field so many researches are in progress. This paper is part of that, we use UAV squad in DTN which is dynamic environments for efficient network structure. Propsed measure use environment information in disparate sensor node and organize UAV squad for stable network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.1049-1052
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• 2009

This paper develop a intelligent personal emergency call system using the wireless sensor network to resolve that a portable problem of established emergency call system. The proposed system is composed of a transmitter nodes for individuals, routing nodes for multihop communications, and a server part. The transmitters for patients are monitored for both low battery and operational status. The transmitters provide location of the person activating an emergency call using RSSI. The efficacy of the proposed system is verified by means of experiments. Experimental results are presented that show the effectiveness.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2021.06a
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• pp.137-140
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• 2021

지상파 UHD 방송은 2017년 세계 최초로 본방송이 시작되었고 2018년 평창 올림픽과 러시아 월드컵을 지상파 UHD 방송으로 중계하면서 성장해 왔다. 그런데 최근 급변하는 미디어 기술과 코로나 19 팬데믹 이후 미디어 시장이 요동치며 미디어 이용 플랫폼과 콘텐츠 그리고 미디어 이용 기기별 사용 시간에도 많은 변화가 생기고 있다. 이에 따라 지난 2017년 본 방송 이후 지상파 UHD 방송에 대한 시청자들의 이용 실태 및 인식 변화에 대한 조사의 필요성이 대두하게 됐다. UHD KOREA와 KBS 공영미디어 연구소는 UHD 방송에 대한 인지도와 시청의향, TV 크기의 변화, TV와 인터넷 연결 여부 등 미디어 환경변화에 따른 시청자의 미디어 이용 형태를 공동으로 조사했다. 그리고 지상파 UHD 방송의 추가 서비스의 선호도와 선호 콘텐츠, OTT 이용 여부 등에 대하여도 분석했다. 지상파 UHD 방송은 고화질, 다채널, 모바일, 재난방송, 양방향 서비스 등 ATSC 3.0 기술을 기반으로 다양한 최신 서비스를 제공하는 것이 가능하다. 이러한 조사 결과는 향후 지상파 UHD 방송 및 미디어 정책의 수립과 추진의 기초 자료로 활용될 것이다.

• KIISE Transactions on Computing Practices
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• v.23 no.4
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• pp.238-243
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• 2017

This paper presents a study regarding a systemic structure that forms a link between heterogeneous terminals and the WebRTC (Web real-time communication) based video-conferencing systems. This system consists of a WebRTC-based terminal, a signal server for the relaying of the necessary signals for media negotiations, an MCU provides an interworking interface for the heterogeneous terminal, and the heterogeneous terminals that interwork with the MCU. This technology enables the interoperability between the WebRTC-based video-conferencing solutions and the legacy devices. In addition to reducing the replacement costs regarding new-technology-based solutions, the existing legacy equipment enables the use of multiparty-conference, thereby increasing the use ability of the conferencing systems.

• The Journal of the Korea Contents Association
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• v.17 no.10
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• pp.576-586
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• 2017

This thesis is a result of studying the combination of text and image based on the achievement of LTP (Literacy Through Photography), a communication education program for young people. This paper presents the LTP program that emphasizes communication functions of images and introduces the results of education conducted to improve the ability of visual communication for adolescents. Adolescents's creative images are analyzed on the basis of three categories of anchors, ealais and illustrations. The questionnaire was a quantitative survey of communication conducted before and after the LTP training. As a result, LTP education showed higher achievement in communication with adolescents when using images than text. In conclusion, this study gives meaning to image utilization education for creativity enhancement and present it as a new education by examining the LTP works and questionnaires of adolescents from communication point of LTP.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.9A
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• pp.850-857
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• 2005

Sensor networks consist of sensor nodes with small size, low cost, lowpower consumption, and multi-functions to sense, to process and to communicate. The main issue in sensor networks has been focused on minimizing power consumption of sensors to maximize network life time. In some critical applications, however, the most important issue is to transmitsensing information to the end user (the sink node) with reliability. Reliable information forwarding using multiple paths in sensor networks (ReinForM) has been proposed to achieve desired reliability in the error-prone channel, but it needs increasing transmission riverhead as the channel error rate becomes high and the number of hops between the source node and the sink node increases. In this paper, we propose a reliable transmission rnechanissmusing intermediate source nodes in sensor networks (ReTrust) to reduce packet overhead while keeping the desired reliability. ReTrust has beenshown to provide desired reliability and reduced overhead via simulationsand analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.11
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• pp.1148-1161
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• 2012

Recently, developments in the field of communication and network technologies induced new paradigm in the defense weapon system. As a consequence, military authorities develop the Tactical Information Communication Network(TICN) system to adapt to the changing paradigm. One of the most important functions of TICN is real-time communication. As a result, TICN system needs to receive real-time information from the battlefield, and the key technology to support these features is MANET(Mobile Ad-Hoc Network) routing protocol. In this paper, we analyze problems of the shortest path scheme in tactical Ad-Hoc networks, which is widely used in common Ad-Hoc networks. We propose efficient routing protocol for tactical MANET by considering the environment of small combat units, such as node position, speed and data size. The proposed algorithm shows reliable data transfer and low latency in battlefield.

• Journal of the Korea Society for Simulation
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• v.17 no.1
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• pp.9-16
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• 2008

The sink mobility can request frequent routing change in sensor networks. By active mobility a sink can gather needed information easily so that the network availability will be higher. However, instead static sink system, the connection between sensor nodes and a mobile sink can be changed continuously. That is, the rerouting should be implemented caused by the routing alteration. It is two connection setups for the mobile sink system: the connection from sink to sensor nodes and the connection from sensor nodes to sink. However, sensor nodes actually have many functional limitations. Hence, the low cost scheme will be needed for the connection setup from sensor nodes to the mobile sink. In this paper, we propose an agent scheme to the connection setup from sensor nodes to the mobile sink. The agent scheme provides the reliable setup scheme to the connection by using an agent sector.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.404-407
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• 2014

Delay Tolerant Network (DTN) is a networking architecture that is designed to solve network problem in unstable and stressed environments using the Store-Carry-Forward method. Different form general networks, DTN does not guarantee the end-to-end connectivity, it is hard for the exiting TCP/IP based protocols to normally work due to the characteristic such as large latency and unstable link connectivity. And the condition that send massage without the information of the destination occurs frequently. Thus, suitable routing protocols for DTN are required and being researched. In this paper, we propose a novel routing protocol for DTN utilizing epidemic and prediction based algorithm to prevent the defect of previously DTN routing protocols such as the absence of the holistic view of the network. Proposed algorithm predicted destination using the mobility information recorded in neighbor node's history and utilize epidemic based algorithm when occurred condition without destination's information. This algorithm is enhanced in terms of delivery ratio, decreases latency and overhead in sparse network such as DTN.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.583-590
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• 2022

With the release of the Bitcoin source in 2009, cryptocurrencies are continuously developing and expanding the market. Recently, new applicability is expanding centered on NFT coin and metaverse payment service. In particular, the Central Cryptocurrency Exchange actively supports relay transactions between cryptocurrencies or between traditional fiat currencies and cryptocurrencies. The cryptocurrency trading market based on such a central exchange encouraged speculative factors of cryptocurrencies, strongly arousing speculation and futility of cryptocurrencies. In addition, the central cryptocurrency exchange induces the centralization of users and virtual assets, thereby hindering the decentralization and security enhancement strategies of the block chain. Therefore, this study describes the current status and problems of centrally controlled centralized cryptocurrency exchanges in service, and presents a distributed cryptocurrency exchange modeling strategy and major issues as a decentralization model of the exchange. This research can strengthen the anonymity, decentralization, and autonomy of cryptocurrency based on blockchain.