• Journal of Navigation and Port Research
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• v.36 no.1
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• pp.1-7
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• 2012

A concept of the "e-Navigation" was introduced in 2005 and implementation strategies are under way by IMO/IALA in the maritime safety area. Specially VTS is an important maritime traffic monitoring and aids to navigation system which is aims to improve safety, navigation efficiency and protect the marine environment. The demand of the inter-VTS networking has been increased and standardization is underway for realization of shore side collaboration for maritime safety in IALA. But there may be security problems in the inter-VTS networks if they have not proper security mechanism. The hacking of realtime ship position and sensitive maritime surveillance information caused a critical accident of vessel, human life and environment by terrorist. This paper aims to design of a secure inter-VTS network structure and related security protocol for secure sharing of sensitive maritime data.

• Journal of Advanced Navigation Technology
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• v.10 no.3
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• pp.262-267
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• 2006

For growing need for the multimedia application in the vehicles, the MOST protocol has been focused on. The MOST protocol supports three kinds of communication modes; short control message, asynchronous packets, and reserved synchronous stream data. Because of a variety of transportation, the MOST is suitable for various applications in vehicle environment. In this paper, we implemented embedded system which is MOST-enabled AMS platform and tested the network communication operation through the control port and the synchronous channel of the source port. We implemented the prototype platforms which communicate each other on the MOST's POF network. Moreover we implemented the DivX decoder attached AMS platform and verified the operation by transferring the video stream and the control messages through the MOST network.

• Journal of Advanced Navigation Technology
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• v.14 no.4
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• pp.521-529
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• 2010

In this paper, we propose a new scheduling algorithms in OFDM systems to reduce inter-cell interference. The proposed algorithm applies different subcarrier allocation sequences for different cells which is optimized through integer programming to minimize inter-cell interference. System level simulation is executed to derive the performance of the proposed algorithm. Simulation results show that the proposed scheduling algorithm improves user fairness as well as throughput compared with previous algorithms and therefore improves support of user QoS.

• Journal of Advanced Navigation Technology
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• v.12 no.3
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• pp.239-244
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• 2008

In this paper refer to the digital multimedia mobile phone with the combination of broadcasting and the communication the unity of wire and wireless solution that can provide the UMA(Unlicensed Mobile Access) function is added. In UNC(Universal Naming Convention) in the case of CAS(Conditional Access System) is supported, the device(mobile phone) is authenticated through AP and then following the method of broadcasting signal the user can view the wanted contents as long as they want and for this matter the service charge system are proposed.

• Journal of Advanced Navigation Technology
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• v.21 no.5
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• pp.423-427
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• 2017

The IMO approved e-navigation strategy implementation plan made e-navigation adoption visible. In addition, the schedule for the modernization of GMDSS by the ITU was confirmed at the 4th NCSR meeting. Accordingly, we will complement the existing communication system and provide the requirements for the new communication system to be introduced in the future, reflecting all the requirements for the communication system capable of supporting the e-navigation service. Although the communication method for supporting e-navigation service should be capable of providing IP-based data communication basically, it is impossible to provide internet service because of the narrow-band characteristic in the MF/HF frequency bands. In addition, as the existing GMDSS satellite communication service organization expands and new services are introduced, IP based data communication service will be possible, but service restriction resulting from expensive communication cost can be solved by introducing VSAT service.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.357-359
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• 2014

해상에서 선박의 안전한 항행을 위하여 항로표지를 운영하고 있으며, 항로표지는 형상표지, 광파표지, 음파표지, 전파표지, 특수신호표지로 구분할 수 있다. 전자기술의 발전과 안전한 항해에 도움을 주는 각종 시스템들이 등부표에 설치되고 있다. 이에 따라 등부표에서의 전력 수요는 과거보다 훨씬 더 많이 요구되고 있는 실정이다. 정부지원 연구과제로 등부표에서 태양광발전, 풍력발전 및 파력발전이 가능한 등부표용 발전시스템을 개발하였으며, 해상에 설치한 등부표에서 각종 에너지원으로 전력의 생산과 등부표 시스템의 운영에 따른 소비에 대한 분석이 필요하다. 현재 해상실험을 진행하고 있으며, TRS기반의 등부표용 통신시스템과 데이터 수신용 모니터링시스템을 설치하였고, 등부표내에서도 메모리카드를 이용하여 전력의 생산과 소비에 관련된 데이터 저장할 수 있게 구성하였다. TRS기반 모니터링시스템에서 저장된 데이터와 등부표에 설치한 메모리카드에 저장된 데이터 분석을 통하여 등부표용 하이브리드 발전시스템의 전력상태를 분석하였다.

• Journal of Advanced Navigation Technology
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• v.16 no.3
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• pp.495-503
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• 2012

As modern society rapidly changes, the field of education has also developed speedily. Since Edunet system developed in 1996, many different systems are developing continuously such as Center for Teaching and Learning, cyber home learning systems, diagnosis prescribing systems, video systems, teaching and counseling, and study management systems. However, the aforementioned systems have had not great response from the educational consumers due to a lack of interconnection. There are several reasons for it. One of the reasons is that program administrators did not carefully consider the continuity of each programs but established a brand new system whenever they need rather than predict or consider the future needs. The suitable system for smart education should be one big integrated system based on many different data analysis and processing. The system should also supply educational consumers various and useful information by adopting the idea of bigdata rather than a single sign on system connecting each independent system. The cloud computing system should be established as a system that can be managed not as simple compiled files and application programs but as various contents and DATA.

• Journal of Advanced Navigation Technology
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• v.14 no.5
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• pp.684-690
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• 2010

Recently, the NG(Next Generation) system is studied for supporting convergence of various services and multi mode of single terminal. And a demand of user for taking the various services is getting increased, for supporting these services, many systems being able to transmit a large message have been appeared. In the NG system, it has to be supporting the CDMA and WCDMA besides the tele communication systems using OFDM method with single terminal An intergrated system can be improved with adopting of SoC technique. For adopting SoC technique on the intergrated terminal, we have to solve the non linear problem of HPA(High Power Amplifier). Nonlinear characteristic of HPA distorts both amplitude and phase of transmit signal, this distortion cause deep adjacent channel interference. We adopt a polynomial pre-distortion technique for this problem. In this paper, a noble modem design for NG mobile communication service and a method using polynomial pre-distorter with PAPR technique for counterbalancing nonlinear characteristic of the HPA are proposed.

• Journal of Advanced Navigation Technology
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• v.17 no.1
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• pp.56-62
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• 2013

Recently with smart phones and tablets, next generation mobile communication systems have supported various multimedia contents services. Thus, multimedia communication systems have been gradually increased compared to voice communication systems. Since the growth of multimedia services has increased users' duration on systems and decreased systems' effectiveness on power, a study on effective usage of power needs to be researched. Furthermore, radio shadow areas under heavy urban environments have generated unnecessary power consumption which reduces the usage duration of power on next generation mobile communication systems. This paper has reviewed the communication network architecture on next generation mobile communication systems and the unnecessary power consumption in radio shadow areas. This paper has also proposed the method of the effective power usage and analyzed the effective power usage on next generation mobile communication systems with simulation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.05a
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• pp.311-313
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• 2018

해양안전심판원의 해양사고 통계자료에 따르면 기관손상 등을 제외한 해양사고 중 충돌사고의 비중은 가장 높고, 대부분의 충돌사고는 경계소흘 등 운항과실이 약 90%를 차지한다. 본 연구에서는 운항자의 항행 안전을 지원하고자 육상 무선 통신기술을 이용하여 중소형 선박의 충돌예방 시스템을 최종적으로 개발하기 위해 먼저 소형어선(30톤미만) 운항자의 요구분석을 수행하였다. 분석을 통해 충돌회피거리, 당직자 배치, 긴급피항시 필요시간, 충돌 및 경보시스템 개발에 필요한 사항 등을 도출하였다. 향후 이를 바탕으로 해상에서의 선박충돌 예방을 위한 신뢰성 높은 충돌경보 알고리즘을 개발 적용하는 등 사용자 편의적인 충돌경보 시스템을 개발하고자 한다.