• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.636-639
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• 2008

The paper deals with the improvement of various characteristics of antenna for VHF mobile handset. In the general case, $1/4{\lambda}$ monopole and helical antenna are used for VHF mobile handset. However, various characteristics of antenna have different result for effect of hand. Especially, radiation efficient is reduced about several dB. In this paper, characteristics of loaded helical antenna have been evaluated. And we propose a method to improve a radiation efficient of antenna consider with hand effect.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.05a
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• pp.237-239
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• 2018

선박관제용 VTS시스템은 레이더, 선박자동식별장치(AIS) 등을 이용하여 정보를 수집하여 관제정보가 필요한 선박국에게 초단파무선통신(VHF)를 통하여 전달한다. 레이더와 선박자동식별장치(AIS) 등은 장비를 이중화하여 안정적인 운영을 할 수 있지만, 관제장비에서 가장 중요한 역할을 담당하는 초단파무선통신(VHF)는 장비만을 이중화하는 것으로 부족한 이유는 바로 주로 선박국이나 육상국에서 일어나고 있는 KEYING현상 때문이다. 최근 제주, 목포, 완도, 여수연안 VTS 등에서 동시 발생한 VHF KEYING 현상을 분석하여 효율적인 대응 방안을 제시하고자 한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.12
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• pp.2232-2240
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• 2017

IMO has made AIS and VHF mandatory for international sailing vessels through SOLAS, and korea if mandating specific vessels through the law for safety of vessels and the ship installation technology standards. However, due to various communication equipments and complicated usage method, malfunction occurs, and the response delay to the actual structure signal often causes human accidents. So recently, as a part of GMDSS modernization, maritime communication devices are attempting to interwork and integrate different types of marine communication system in order to construct a next generation maritime communication system. In this paper, we describe a technique to implement the DSC function by interlocking and integrating the AIS device and VHF. We will present the basis for achieving domestic technical standards and standardization through the linking algorithm of the data that can extract the ship information from AIS and utilize it the DSC function of VHF.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.4
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• pp.692-698
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• 2001

The radio communications by SSB and VHF transceivers are still used very efficiently in coast stations and military base stations. The communication system by the conventional SSB and VHF transceivers between a coast station and a terminal is an one-to-one system. In this dissertation, however, the conventional one-to-one system is expanded to one-to-multiple systems. Then, frequencies can be used effectively for distress, urgency, safety traffic, and military communications. An ICS has been proposed and added, in this dissertation, to the conventional SSB and VHF communication systems, which can realize one-to- several terminal communications. The line switching system by the ICS is to be remote-controlled by ASK modulated PTT signals and audio signals. An ICS can change a connection between terminal and transceiver through a circuit switching system at any time. For this purpose, the author has researched and developed a ASK transmission system, ICS system, control algorithm, multiprocessor system, and moni-toring system. As a conclusion, the developed line switching control systems and equipments can be used effectively for maritime communication, military communication, fishery communication, etc.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.6A
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• pp.438-449
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• 2012

This paper presents new CRC-p codes for VHF band maritime wireless communication system based on performance analysis of various CRC codes. For this purpose, we firstly describe the method of determination of undetected error probability and minimum Hamming distance according to variation of CRC codeword length. By using the fact that the dual code of cyclic Hamming code and primitive BCH code become maximum length codes, we present an algorithm for computation of undetected error probability and minimum Hamming distance where the concept of simple hardware that is consisted of linear feedback shift register is utilized to compute the weight distribution of CRC codes. We also present construction of transmit data frame of VHF band maritime wireless communication system and specification of major communication parameters. Finally, new optimal CRC-p codes are presented based on the simulation results of undetected error probability and minimum Hamming distance using the various generator polynomials of CRC codes, and their performances are evaluated with simulation results of bit error rate based on the Rician maritime channel model and ${\pi}$/4-DQPSK modulator.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.929-932
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• 2013

In preperation for the compulsory installation of VHF(Very High Frequency) wireless equipment and fishing vessel automatic identification system according to the revision of "The Ships Safety Act" and "Fishing Vessel act", Fishery Information & Communication Department of National Federation of Fisheries Cooperatives is building VHF communication network and automatic identification system for fishing vessel monitoring. This study suggests the protocol analysis for the calling of location requirement using DSC(Digital Selective Calling) function and show best way for fishing vessel automatic identification system. Also, it suggest way to realize fishing vessel monitoring system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2800-2805
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• 2013

In preperation for the compulsory installation of VHF(Very High Frequency) wireless equipment and fishing vessel automatic identification system according to the revision of "The Ships Safety Act" and "Fishing Vessel act", Fishery Information & Communication Department of National Federation of Fisheries Cooperatives is building VHF communication network and automatic identification system for fishing vessel monitoring. This study suggests the protocol analysis for the calling of location requirement using DSC(Digital Selective Calling) function and show best way for fishing vessel automatic identification system. Also, it suggest way to realize fishing vessel monitoring system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.06a
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• pp.276-278
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• 2014

VDES는 최근 IMO에서 e-Navigation 및 GMDSS 현대화작업과 관련하여 도입을 추진 중인 해상에서의 VHF 디지털 통신시스템이다. VDES는 기존의 AIS 뿐만 아니라 디지털 VHF에 해당하는 VDE와 AIS 응용서비스인 ASM 및 위성 VDE까지 포함하는 광범위한 개념으로 검토되고 있다. VHF 디지털 통신용 주파수의 기본적인 분배는 이미 완료되었으며, 일부 세부내용은 2015년에 결정되고 2017년부터 적용될 예정이다. 우리나라에서도 e-Navigation과 더불어 VDES 도입을 적극 검토하고 있다. 여기에서는 VDES를 도입 적용하는데 있어서 고려해야 할 주파수와 간섭문제 등에 대하여 분석하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.261-264
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• 2005

In this paper, wish to improve reception performance of general receiver manufacturing broadband reception amplifier that can thread easily in VHF transmit-receive equipment into downsize, light weight, low-cost. Manufactured reception amplifier expressed Characteristic that improve reception sensitive 3dBm in 140MHz ${\cdot}$ 170MHz frequency band. Therefore, may use communications equipment that utilize VHF wide-band more efficiently. Also, practical use degree is considered to be very high because telecommunication of good quality is available.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.1
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• pp.19-25
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• 2003

The radio communications by SSB and VHF transceivers are still used very efficiently in coast stations. The SSB and VHF equipments are very important to transmit and receive informations in the sea and the land. The communication system by the conventional SSB and VHF transceivers between a coast station and a terminal is an one-to-one system. In this dissertation, however, the conventional one-to-one system is expanded to one-to-multiple systems. Then, frequencies can be used effectively for distress, urgency, safety traffic. In addition, one to multi-number systems can be used to interrupt. When the ICS equipments are set up to the VHF transceiver. It is possible to communicate with ship in far distance the communication range can be enlarged. The line switching system by the ICS is to be remote-controlled by ASK modulated PTT signals and audio signals. An ICS can change a connection between terminal and transceiver through a circuit switching system at any time. For this purpose, the author has researched and developed a ASK transmission system, ICS system, control algorithm, multiprocessor system, and monitoring system. As a conclusion, the developed line switching control systems and equipments can be used effectively for maritime communication, military communication, fishery communication, etc.