• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.1
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• pp.122-127
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• 2009

In this paper, it is reviewed security architecture and proposed security model about secure aeronautical system, which is considering in the cynical research topics out of aeronautical traffic system. The reviewed contents is treated about security model fur domestic aeronautical system with international security technology trends in the basis of security technology related aeronautical services. In the security framework of aeronautical communication network, it is analyzed data link security technology between air and ground communication, and security architecture in according to aeronautical system, and presented security architecture of U information HUB model. The security architecture of U-information HUB includes the internetworking scope of airline, airport network, airplane network, and related government agency, etc.

• Journal of Communications and Networks
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• v.17 no.1
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• pp.58-66
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• 2015

Aeronautical communication networks (ACN) is an emerging concept in which aeronautical stations (AS) are considered as a part of multi-tier network for the future wireless communication system. An AS could be a commercial plane, helicopter, or any other low orbit station, i.e., Unmanned air vehicle, high altitude platform. The goal of ACN is to provide high throughput and cost effective communication network for aeronautical applications (i.e., Air traffic control (ATC), air traffic management (ATM) communications, and commercial in-flight Internet activities), and terrestrial networks by using aeronautical platforms as a backbone. In this paper, we investigate the issues about connectivity, throughput, and delay in ACN. First, topology of ACN is presented as a simple mobile ad hoc network and connectivity analysis is provided. Then, by using information obtained from connectivity analysis, we investigate two communication models, i.e., single-hop and two-hop, in which each source AS is communicating with its destination AS with or without the help of intermediate relay AS, respectively. In our throughput analysis, we use the method of finding the maximum number of concurrent successful transmissions to derive ACN throughput upper bounds for the two communication models. We conclude that the two-hop model achieves greater throughput scaling than the single-hop model for ACN and multi-hop models cannot achieve better throughput scaling than two-hop model. Furthermore, since delay issue is more salient in two-hop communication, we characterize the delay performance and derive the closed-form average end-to-end delay for the two-hop model. Finally, computer simulations are performed and it is shown that ACN is robust in terms of throughput and delay performances.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.3
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• pp.22-27
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• 2012

In oceanic flight routes, HF radio and satellite data links have been used for air-to-ground communication, but these systems have long propagation delay and low data throughput. In this paper, we propose a reliable system to overcome the weakness of current HF radio and satellite communication systems for oceanic aeronautical flight routes. The proposed scheme uses only one aeronautical VHF channel in multi-hop oceanic communication environments and supports a hybrid type of multiple access, which consists of random access and TDMA (Time Division Multiple Access) scheme. The proposed system improves performance on delay and throughput as an effective solution to communicate end-to-end on the oceanic flight routes and strengthens the reliability of oceanic aeronautical communication.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.4
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• pp.45-49
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• 2012

VDL(VHF Data Link) Mode E uses TDMA(Time Division Multiple Access) based aeronautical communication technologies for airborne environments. In the VDL Mode E, aircraft uses RR(Reservation Requests) slot to request data slot. However, RR needs a long guard time, since aircraft communication spans a considerable distance. The more number of aircrafts causes a larger amount of guard times which can make a throughput decreased. In this paper, we propose an enhanced MAC to reduce the guard time by using the distance information of aircraft. The ground station sends management data including time stamp. And then all aircraft can measure their distance from the ground station.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.435-436
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• 2018

본 논문에서는 가상현실 기반의 게임과 사용자(Player)간의 상호작용이 가능한 게임 컨텐츠 개발 방법을 설명한다. 사용자는 실시간으로 본인의 움직임에 의해 변화하는 오브젝트들을 통해 게임과 소통(Communication)하고, 이를 통해 몰입감을 느낀다. 사용자와 컨텐츠의 소통이 곧 게임 내 재미의 핵심인 만큼 최근에는 이동 방식에서부터 차츰 변화가 일어나고 있다. 또한, 단순히 물건을 집거나 쏘거나 던지는 것이 고작이었던 과거의 콘텐츠(Contents)와 달리 사고(Thinking)와 문제해결을 유도하는 콘텐츠가 차츰 늘어나면서 사용자들의 만족감이 높아지고 있다. 이를 바탕으로 게임엔진인 Unreal Engine4를 이용하여 VR 어드벤처 퍼즐 게임을 제작했다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.2
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• pp.136-144
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• 2002

• Journal of the Korean Society for Aviation and Aeronautics
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• v.21 no.1
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• pp.15-22
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• 2013

In oceanic flight routes, HF radio and satellite data links have weather restrictions, long propagation delay and low data throughput. In this paper, we propose oceanic aeronautical communications scheme in the VHF band based on ad-hoc communication. The proposed scheme organizes autonomously a multi-hop network that is divided into multiple local network using aircraft to fly long-distance communication and supports a hybrid type of multiple access, which consists of random access and TDMA (Time Division Multiple Access) scheme. In addition, several algorithms to apply spatial reuse of transmission to multi-hop long range communication environments have been proposed. The proposed system proves performance improvement on delay time as an effective solution to communicate end-to-end on the oceanic flight routes and strengthens the reliability of oceanic aeronautical communication.

• Journal of Advanced Navigation Technology
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• v.7 no.2
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• pp.199-205
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• 2003

In this paper, CSMA/CA protocol is modified for aeronautical VHF communication through collision alleviation and the change of retransmission slot selection method in flag used transmission. When collision occurred in the contention period of CSMA/CA process, it is generally waiting for retransmission delay and it has the double size of CW(Contention Window). To solve this problem, this paper modifies the change procedure of original contention window size and reduces the state transition in collision among the whole of it. Also, in this paper we reduces the second collision probability through the station has to enter Backoff mode with increased contention window in the first collision. In the result of simulation, it is verified that it has good property in throughput and delay, So the proposed protocol is suitable for aeronautical VHF communication.

• Journal of Advanced Navigation Technology
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• v.19 no.2
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• pp.140-146
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• 2015

Due to the increase in the data traffic for the aeronautical communications, LDACS has been proposed to support the data link in the continental domain. LDACS is defined in two standards of LDACS type-1 and LDACS type-2, which are going to be selected through the intensive comparison. In this paper, we analyzed two types of standards and evaluated their performance for various channel models. Simulation results show that both LDACS type-1 and LDACS type-2 have a good performance in the en-route channel model, while they have a poor performance in the airport channel model. In the comparison results for LDACS type-1 and LDACS type-2, LDACS type-1 shows the better performance of 1dB than LDACS type-2 owing to the stronger channel coding technique.

• International Journal of Aeronautical and Space Sciences
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• v.3 no.2
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• pp.40-45
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• 2002

A radiation analysis is performed for the Ka and Ku-band transponder of the Communications and Broadcasting Satellite (CBS) that is planned for launch into the geo-synchronous orbit. A particular attention is given to calculation of Total Ionizing Dose (TID) for the mission life time of 15 + 3 years. A numerical modeling of the charged particles at the geo-synchronous orbit is undertaken. The charged particles from the modeling are then transported through the mechanical structure and component housings of the transponder. A set of locations are selected for the detailed calculation of TID. The results from the present calculation show that three-dimensional modeling of the component housings as well as the mechanical structure of the spacecraft is requisite in order to acquire a reliable calculation of TID.