• Proceedings of the SAREK Conference
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• 2004.06a
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• pp.151-151
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• 2004

• Journal of the Korea Convergence Society
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• v.7 no.4
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• pp.25-32
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• 2016

When using reliable multicast protocol over air links, the multicast packets lost in the air link cause the initiation of retransmission request packets and the implosion of retransmission packets, which deteriorate multicast session performance. This paper proposes on the efficient reliable multicast mechanism in wireless networks utilizing the Agents. In this paper we show the design of a retransmission agent which improves the performance of reliable multicast sessions in wireless network. The main idea is to cache reliable multicast packets at the base station and perform local retransmissions across the wireless link. MATLAB has been used to simulate and to get performance results for signaling overhead and processing delay through the comparison of the proposed agent model to the Multicast File Transfer Protocol. It has been proven from the simulation results that the proxy module make pass trials shorter in Multicast File Transfer Protocol.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.485-488
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• 2000

This paper proposes to design the residential power line communication device using Softwire Protocol, which targets the device with 8bit micro-controller and small-size memory based on low-rate power line communication network or wireless communication network. As a case study, the SCP message specification of air-conditioner that has capability of control and monitoring its status is designed using Softwire Protocol. And, it is described how the device operates sequentially.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.1
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• pp.44-49
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• 2011

The need of data transmission in oceans and other underwater mediums are increasing day by day, so as the research. The underwater medium is very different from that of air. Propagation of electromagnetic wave in water or underground is very difficult because of the conductivity of the propagation materials. In this case, we usually use acoustic signals as ultrasonic but, they are not easy to transfer long distance with coherent method because of time varying multipaths, Doppler effects and attenuations. So, we use non-coherent methods such as FSK or ASK to communicate between long distances. But, as the propagation speed of acoustic wave is very slow, BW of the channel is narrow. It is very hard to guaranty the enough speed for the transmission of digital image data. In previous studies, we proposed this data communication protocol theoretically. In this paper, an underwater channel is modeled and this protocol is tested in this channel condition. The results show that the protocol is 4-6 times faster than ASK. Some relations and results are shown depending on the data length, channel length, bit rate etc.

• Journal of Korea Multimedia Society
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• v.21 no.8
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• pp.897-908
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• 2018

In this paper, we propose a security framework for a cluster drones network using the MAVLink (Micro Air Vehicle Link) application protocol based on FANET (Flying Ad-hoc Network), which is composed of ad-hoc networks with multiple drones for IoT services such as remote sensing or disaster monitoring. Here, the drones belonging to the cluster construct a FANET network acting as WTRP (Wireless Token Ring Protocol) MAC protocol. Under this network environment, we propose an efficient algorithm applying the Lightweight Encryption Algorithm (LEA) to the CTR (Counter) operation mode of WPA2 (WiFi Protected Access 2) to encrypt the transmitted data through the MAVLink application. And we study how to apply LEA based on CBC (Cipher Block Chaining) operation mode used in WPA2 for message security tag generation. In addition, a modified Diffie-Hellman key exchange method is approached to generate a new key used for encryption and security tag generation. The proposed method and similar methods are compared and analyzed in terms of efficiency.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.07a
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• pp.243-244
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• 2019

본 논문에서는지속 가능한 IoT Platform을 개발 하였다. 개발된 IoT(Internet of Things) Platform은 센서를 제어하는 특정 시스템과의 통신을 통한 제어 및 데이터 전달에 용이하고, 제한된 통신 환경 및 낮은 전력에서도 지속적인 작동이 가능하여 가용성(Availability)과 확장성(Extensibility)이 뛰어나다. 본 논문에서는 지속 가능한 IoT Platform의 테스트를 위해 클라우드 컴퓨팅 플랫폼인 AWS EC2(Amazon Elastic Compute Cloud, EC2)에 구축하였으며, DataBase 서버로는 오픈 소스 관계형 데이터베이스 관리 시스템인 MariaDB를 선정하였으며, 센서를 제어하는 특정 시스템인 스마트 미러 시스템(Smart Mirror System)과 미세먼지 제어 시스템(Air Quality Control System)에 기존의 Google IoT Platform에서 사용되는 MQTT Protocol(Message Queuing Telemetry Transport Protocol)와 지속 가능한 IoT Platform를 위해 개발된 TCP/IP Protocol를 사용하여 비교했다. 개발된 IoT Platform은 UTM(Unmanned Aircraft System Traffic Management)으로 확장할 계획이다.

• International Commerce and Information Review
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• v.12 no.2
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• pp.385-405
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• 2010

The purpose of this study is to investigate liability risk of air cargo carrier and suggests ideas for solving problems which could be happen to air transporters on the future. because of Air transport remains one of the world's fastest growing and most important industries. And important treaties and contracts specifying transporters' responsibility regarding big scale aircraft accidents are such as Warsaw Convention in 1929, Hague Protocol in 1955, Montreal Convention in 1999. The Montreal Convention, formally the Convention for the Unification of Certain Rules for International Carriage, is a treaty adopted by Diplomatic meeting of ICAO member states in 1999. It amended important provisions of the Warsaw Convention's concerning compensation for the victims of air disasters. In conclusion, suggests to the method of air cargo security and cargo legal liability insurance which is for air cargo carrier's risk management.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.1
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• pp.111-118
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• 2013

This paper presents implementation of Air protocol analyzer and physical layer design algorithm. The analyzer is a measurement system providing real-time analysis of wireless signals between User Equipment (UE) and Node-B. The implemented system proposed in this paper consists of Digital Signal Processors (DSPs) and Field Programmable Gate Arrays (FPGAs). The waveform of Wideband Code Division Multiple Access (WCDMA) has been selected for verification of the proposed system. We designed the analyzer using equalizer algorithm and rake-receiver algorithm. Among various algorithms of designing the equalizer, we have chosen Linear Minimum Mean Square Error (LMMSE) equalizer that uses the inverse of channel matrix. Since the LMMSE equalizer uses the inverse channel matrix, it suffers from a large amount of computational load, while it outperforms most conventional equalizers. In this paper, we introduce an efficient procedure of reducing the computational load required by LMMSE equalizer-based receiver.

• The Korean Journal of Air & Space Law and Policy
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• v.22 no.1
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• pp.125-162
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• 2007

The Convention on International Interests in Mobile Equipment and the Protocol to the Convention on International Interests in Mobile Equipment on Matters specific to Aircraft Equipment were adopted on 16 November 2001 at a diplomatic conference held in Cape Town under the joint auspices of UNIDROIT and ICAO. The entry into force of the Cape Town Convention and Protocol have occurred on 1 March 2006. The Cape Town Convention and Protocol provides an international legal regime for the creation, perfection and priority of security, title retention and leasing interests in aircraft equipment, which will be underpinned by an international registry. The purpose of this paper is to explain the objectives and principles of the Cape Town Convention and Protocol, to review the provisions relating to the international interests in aircraft equipment and international registry for their protection under the Cape Town Convention and Protocol, and to discuss the Issues on Korea's accession to the Cape Town Convention and Protocol. As the anticipated results of this paper, it will contribute to facilitate the financing of the acquisition and use of aircraft equipment of high value or particular economic significance in an efficient manner, and to save very large sums of money annually in financing charges, also the international interests in aircraft equipment will be recognized and protected universally.

• The Korean Journal of Air & Space Law and Policy
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• no.spc
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• pp.105-135
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• 2007

The Convention on International Interests in Mobile Equipment and the Protocol to the Convention on International Interests in Mobile Equipment on Matters specific to Aircraft Equipment were adopted on 16 November 2001 at a diplomatic conference held in Cape Town under the joint auspices of UNIDROIT and ICAO. The entry into force of the Cape Town Convention and Protocol have occurred on 1 March 2006. The Cape Town Convention and Protocol provides an international legal regime for the creation, perfection and priority of security, title retention and leasing interests in aircraft equipment, which will be underpinned by an international registry. The purpose of this paper is to explain the objectives and principles of the Cape Town Convention and Protocol, to review the provisions relating to the international interests in aircraft equipment and international registry for their protection under the Cape Town Convention and Protocol, and to discuss the Issues on Korea's accession to the Cape Town Convention and Protocol. As the anticipated results of this paper, it will contribute to facilitate the financing of the acquisition and use of aircraft equipment of high value or particular economic significance in an efficient manner, and to save very large sums of money annually in financing charges, also the international interests in aircraft equipment will be recognized and protected universally.