• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.382-384
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• 2008

D-TRS is a method of wireless communication. This method will be able to use several frequency for multiple user used chanel together. TETRA of D-TRS technology is not rented network. Using TETRA network has the strong point which cost better than CDMA network of rental network. Master server of SCADA(Supervisory Control And Data Acquisition) system is realtime supervise control and a data acquire the control system or the RTU(Remote Terminal Unit). The present paper is developed and proposal the gateway platform for electronic power backbone network based on D-TRS. This gateway platform is converted DNP3.0 messages with TETRA PDU and converted TETRA PDU with DNP3.0 messages. Master server and FRTU will be able to send and receive DNP3.0 message via TETRA network using this gateway platform.

• Journal of the Korean Institute of Navigation
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• v.22 no.2
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• pp.13-22
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• 1998

Shipbome Automatic Identification System (AIS) will be an important manne equipment used for identification, surveillance and communication in the 21st century, which is currently being researched in developed countries. A technical scheme of AlS is proposed in this paper. The main component of the AlS is a broadcast transponder, and the core technology is a VHF radio data link with high capacity, named STDMA (Self-organized Time Division Multiple Access). The ships installed the AlS, which will automatically and periodically broadcast their positions and identities in the marine VHF channels, can be displayed on a screen of an ECDIS on board or in VTS centers. The AlS is able to support not only broadcast service but also point-to-point communication service. This paper presents the configuration, operation principle and functionality of the AlS as well as the scenario of STDMA. In addition, the standardization work of AlS in IMO is introduced in this pauer, too.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.4
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• pp.437-448
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• 2015

In this paper, smartphone based measuring device was developed by integration of several sonsors such as moving, temperature, pulsation, respiration and hearing and sever/client programs was developed for the data acquisition and communication between smartphone and server computer. Then, the concept of CSI(combined safety index) was proposed for the comprehensive diagnositcs of workers status. For the validation of the proposed concept, the real data was acquired by boarding at training ship of korea maritime and ocean university. The acquired data was analyzed with the stochastical method of regressionn, then the meaningful result was driven that could explain the relation between the risky situation and the measured chronical data.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2003.05a
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• pp.75-80
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• 2003

The Ministry of Maritime Affairs ＆ Fisheries have plaining the advancing fishery information integrated system for the fishing present condition, marine resource administration and applicability considering. The fishery information communication system is build up to the raw date ＆ process-network-content. The communication system must be small size, low cost and adapted SSB transceiver, that is using fishery shipping. In this paper We present digital data communication network to exchange information for fishery and safety between fishing ship and coast station in cheeper communication free using SSB(Single Side Band) in HF(High Frequency) band.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.430-432
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• 2013

AIS(Automatic Identification System) is a radionavigation equipment for exchanging safety related information between ships as well as ship and shore station, introduced by SOLAS convention and widely used especially in vessel traffic service. However, in an area of broad communication coverage of coast station, various problems may appear in receiving AIS data from ships. In this paper, AIS problems that may happen in broad communication coverage of coast station are analyzed using received data.

• Journal of Navigation and Port Research
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• v.47 no.2
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• pp.85-92
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• 2023

The hardware of an LED lighting control system for coastal lighting at coastal pier entrance consists of a power supply unit, an AVR control unit, a CLCD output unit, an LED control unit, a scenario selection switch unit, and an operation speed display unit. It is made of an 8-channel. The CPU used ATmega128 and the FET was used to control the current signal. To operate the CPU, DC 12V was converted to DC 5V using a regulator 7805. A heat sink was used to remove heat generated in the FET. By connecting the load LED module to the manufactured 8-channel LED lighting control system, the operation was confirmed through various production scenarios. In addition, a control system was designed to show the most suitable color for the atmosphere of the coastal pier according to the input value of temperature and illumination using a fuzzy control system. Computer simulation was then conducted. Results confirmed that fuzzy control did not need to store many data inputs due to characteristics of artificial intelligence and that it could efficiently represent many output values with simple fuzzy rules.

• ETRI Journal
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• v.26 no.2
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• pp.149-160
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• 2004

In this paper, we present an interactive data broadcasting system compliant with the Advanced Television Systems Committee (ATSC) standards. The proposed system provides users not only with various data broadcasting services but also remote interactive services. For various data broadcasting services, we have adopted a synchronized data injector that calculates the transmission time of synchronized data accurately and multiplexes synchronized data with the data of an MPEG-2 audio-visual program according to the calculated transmission time. To support remote interactive services, we designed and implemented a return channel server connected on a bi-directional interaction channel. Test results show that the proposed system provides both an asynchronous and synchronized data broadcasting service and remote interactive service appropriately.

• Journal of Broadcast Engineering
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• v.24 no.7
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• pp.1221-1227
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• 2019

This paper describes a low-density parity-check (LDPC) coded index modulated orthogonal frequency division multiplexing with quasi-orthogonal sequence (IM-OFDM-QOS) and provides performance evaluations of the proposed system. By using QOS as the spreading code, IM-OFDM-QOS scheme can improve the reception performance than IM-OFDM-SS scheme for a given data rate. On the other hand, LDPC code is widely used to the latest wireless communication systems as forward error correction (FEC) scheme and has Shannon-limit approaching performance. Therefore, by applying LDPC code to IM-OFDM-QOS system as FEC scheme, the reception performance can be further improved. Simulation results show that significant signal-to-noise ratio (SNR) gains can be obtained for LDPC coded IM-OFDM-QOS system compared to the LDPC coded IM-OFDM-SS system and the SNR gain increases with the higher code rate.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.7
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• pp.1515-1521
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• 2013

AIS is a core service in the maritime safety domain. AIS Message type #6 and #8(for binary date) can be used for carrying any kind of MSI(Maritime Safety Information). The MSC(Maritime Safety Committee) approved SN/Circ. 289 on Guidance on the use of AIS Application-Specific Messages in 2010. The MSI that carried by AIS-ASM can support to reduce the maritime accidents. Since a new AIS-ASM service places an additional load on the VDL(VHF Data Link), there should be a deployment process for new AIS-ASM services. In this paper we analyze the AIS-ASM services and survey the extended functions and systems for each AIS-ASM service. We also present the survey of the statistical analysis of local AIS messages. and suggest preliminary research topics for the deployment of new AIS-ASM services. VDL monitoring system, system for detection and removal of malfunctioning AIS equipments, and value analysis process of the MSI services are required.

• Journal of Navigation and Port Research
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• v.29 no.1 s.97
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• pp.23-28
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• 2005

The signal in wireless multi-path channel is affected by fading and ISI because of high data rate transmission, so the signal has the high error rate. The present modulation and demodulation method of DSRC system can not expect sufficient for providing data service over 1 Mbps, so the channel equalization and advanced modulation and demodulation methods are required. OFDM is generally known as an effective technique for high data rate transmission system, since it can prevent ISI by inserting a guard interval. However, a guard interval longer than channel delay spread has to be used in each OFDM symbol period, thus resulting a considerable loss in the efficiency of channel utilization Therefore the equalizer is necessary to cancel ISI to accommodate advanced ITS service with higher bit rate and longer channel delay spread condition In this paper, the channel equalizer for the OFDM -DSRC system was designed and its performance in a multi-path fading environment was evaluated with computer simulation.