• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.290-294
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• 1999

This paper describes the design and implementation of an intranet-based message and file transfer system using the INMARSAT-C for easy transmission and user-friendly interface. For these, onboard LAN including telex, printer and database with centralized one server is designed and constructed. Also, onboard computing environment which provides the INMARSAT-C terminal and RS-232C link interface built in with effective intranet-based web mail system between the ship and land.

• Journal of the Korean Institute of Navigation
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• v.20 no.2
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• pp.77-84
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• 1996

This is the first report about the development of INMARSAT-C Satellite communication terminal. We analyze the existing Inmarsat-C terminal and examine each rules(IMO rule, domestic rules) about terminal. With that result, we design the basic hardware and software of terminal. This report consists of ; 1) the contents of the overall of operating situation and resources of INMARSAT-C system as like operation of communication system, communication channels and services 2) the contents of the specification of Inmarsat-C terminal hardware and software and the rules of IMO and Type approval 3) the design of basic hardware and reserch of signal modulation/demodulation using Viterbi algorithm 4) the design of software algorithms and functions focused in korean situations.

• Journal of the Korean Institute of Navigation
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• v.24 no.4
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• pp.299-312
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• 2000

Because shore(ship) to ship(shore) communication service via INMARSAT pay expensive cost, satellite service typically use two stage service that land users dial up LES(Land Earth Station) for sending or receiving message. In order to send and receive message, land users must maintain online state with LES on dedicated line. Also, two stage INMARSAT communication service must consume long time that processes step by step. In case of large company, they have own communication system, but small companys communicate simple messages with only telex. This paper describes the design and implementation of an integrated communication services via INMARSAT-C. This system uses inexpensive INMARSAT-C for transmission between ship and land. Because this system provides web and E-Mail interface, users send and receive messages easily and quickly. This system provides most users with inexpensive and easy communication facilities between ship and land.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1998.11a
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• pp.257-262
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• 1998

본 논문에서는 DSP(Digital Signal Processor)를 이용해 INMARSAT-M 위성통신용 단말기 중의 변ㆍ복조부를 설계하였다. R-RC(ROOt Raised Cosine) 필터에 의해 대역제한된 OQPSK 파형의 발생과 디지털 정합필터(Matched filter)를 이용한 OQPSK 복조, 부호율 1/2이고 구속장이 7인 길쌈부호기 및 클록 복구(Clock recovery)의 구현 알고리즘을 C언어와 어셈블리어로 작성하고, 모뎀을 실제 제작하여 변조기능, 복조기능으로 나누어서 동작 특성을 살펴보았다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.1
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• pp.141-153
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• 1999

This paper presents the design and implementation of Internet-based message transfer agent via INMARSAT-C between the land and ship for the convenient message transfer service using the Internet mail or Web. In order to achieve these purpose, overall system configuration for communication between the land and ship, agent modules and database for managing transmission and receiving data are described. For the validity evaluation of this paper, message parsing, database, message format and X.25 interface modules are implemented and tested. Based on the result, the capabilities of ship automation system and ownship database access are discussed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.213-217
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• 1999

This paper describes a methodology of database synchronization between ship and land. Through this synchronization, consistency can be maintained between land's database and ship's database. Onboard useful data is sent from ship's database to land' database at time interval via the INMARSAT-C which satisfies with the GMDSS requirements and supports transport service. eased on the result of the paper, user can access land's database which is synchronized with ship's database.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.2
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• pp.339-346
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• 1999

A RF receiver section for INMARSAT-C external mounting unit was designed, fabricated and evaluated. Using a INA-03184, the high gain amplifier consists of matched amplifier type. Active bias circuitry can be used to provide temperature stability without requiring the large voltage drop or relatively high-dissipated power needed with a bias stabilization resistor. The bandpass filter was used to reduce a spurious level. As a result, the characteristics of the receiver section implemented here show 60 dB in gain, 44.83 dBc in a spurious level. The voltage standing wave ratios(VSWR)of input output port are less than 1.8:1, respectively.

• Journal of the Korean Institute of Navigation
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• v.22 no.2
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• pp.33-38
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• 1998

Approximate design formulse for bandpass filter using stepped microstrip lines are derived. The coupling length of which can be adjusted according to the factor K.Some advantages fo this filter, thus, are the abilities to control the size and shape by changing the structure of the resonator. Using the design formulas an experimental filter was designed and fabricated . The experimental results have been agree with the designed ones, and hence, the validity of the proposed method has been confirmed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.2
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• pp.281-290
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• 1999

This paper presents the development of a high power amplifier for a transmitter of INMARSAT-C operating at L-band(1626.5∼1646.5 MHz). To simplify the fabrication process, the whole system is designed of two parts composed of a driving amplifier and a high power amplifier The HP's AT-41486 is used for driving part and the SGS-THOMSON microelectronics' STM1645 is used the high power amplifier. The SSPA(Solid State Power Amplifier) was fabricated by the both circuits of RF and temperature compensation in aluminum housing. The realized SSPA has more than 36 dB for small signal within 20MHz bandwidth, and the voltage standing wave ratios(VSWR) of input and output Port are less than 1.5:1, respectively. The output Power of 42.2 dBm is achieved at the 1636.5 MHz. These results reveal a high power amplifier of 20 Watt which is the design target.

• Journal of Advanced Navigation Technology
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• v.20 no.1
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• pp.93-98
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• 2016

The purpose of this study is to design for MOB antenna attached on safety helmet using microstrip patch antenna. The patch antenna is fabricated in 0.2 mm FR-4 substrate with $64{\times}64mm$ size. The proposed antenna is based on a slot-ring design which cover Inmarsat (1.52 ~ 1.65 GHz) and GPS (1.575 GHz) frequency band. To obtain the optimized parameters, HFSS simulator is used, and antenna is designed by optimized parameters. After antenna was etched, SMA connector was attached to the microstrip feeding line and the result between antenna simulation and measurement was analyzed. Proposed antenna is satisfied the -10 dB bandwidth requirement while simultaneously covering the 1.53 ~ 1.65 GHz.