• Journal of Advanced Navigation Technology
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• v.23 no.2
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• pp.194-199
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• 2019

Natural disasters destroy decades of human effort and investments, thereby placing new demands on society for reconstruction and rehabilitation. In most case, the natural phenomena triggering the disasters are beyond human control. In order to solve the problems that the information resources can not be shared among disaster management sectors and their work is hard to be coordinated in city, an idea of application of ubiquitous sense network and ICT technology to model the architecture of the disaster prevention system based on the analysis of characteristics of disasters. The proposed algorithm simulated that it is possible to locate the terminal by linking the direction angle and the estimated position that can be confirmed at the time of stopping, even if the movement direction of the terminal does not move in a certain direction with only a smaller number of mobile base stations. We also confirmed that the proposed algorithms analyzed through simulation are more efficient than existing algorithms.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.1
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• pp.49-57
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• 2019

The International Maritime Organization is developing a maritime safety system called eNavigation in order to effectively respond to accidents occurring on board vessels. Korea is actively participating in the development of eNavigation and is developing Korean eNavigation by adding its own concept to eNavigation of the IMO. eNavigation is designed to provide various functions for marine safety. The data required for each function is various such as spatial data, relational data, file, weather grid. Therefore, there is a need for a system that can appropriately provide heterogeneous data suitable for eNavigation to each eNavigation's service system. In this paper, we analyzed the kinds of data needed for e-Navigation and designed the architecture of heterogeneous data service system that could provide these data properly.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.186-189
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• 2019

The technique named CORD is an algorithm that optimizes resources of Data Service Platform(DSP) in real time, and it has been developed for enhancing operability of DSP of Korean e-Navigation Project performed by Hanwha Systems and Ministry of Oceans and Fisheries(MOF) since 2016. It plays a critical role to recognize the state of DSP in early time and handling problems immediately when it occurs logical, physical error in order to make DSP steady state condition, which has something in common with maximizing operability of DSP and seamless maritime service to various ships in the sea. Therefore, as developing a noble technique that makes DSP steady state by diagnosing resource and operation status of DSP as well as by reconfiguring service queue optimally in real time, DSP can have shorter response time and higher chance of providing proper maritime service to ships in voyage.

• Journal of Advanced Navigation Technology
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• v.23 no.5
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• pp.430-436
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• 2019

It is needed to develop an antenna with features of subminiature, light weight and multi-band operation for the variaty services in maritime and industrial fields. The PCB pattern antenna is one of the appropreiate antennas solving these requirements. In this research, the design and fabrication of the PCB pattern antenna operating on the single band of 920 MHz are investigated. The final goal is that the development of the dual band PCB pattern antenna operating on 260 MHz and 920 MHz, which is based on the proposed antenna. It is evident that the performance in the frequencies of 902 MHz, 915 MHz and 928 MHz among of 920 MHz ISM band is better than that in other frequencies. It is also confirmed that the differences of the voltage standing wave ratio, return loss, gain and efficiency between three frequencies are less than 5%. It is expected that the development of communication link of 5-10 km is possible when the induced results are applied into the low power wide area (LPWA) network desinged by the rule of -30 dB sensitivity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.375-378
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• 2014

Marine disaster, such as 'the sinking of the Sewol ferry', on the ocean needs emergency communication with land post and Rescue services. Especially, It needs of emergency comomunication system has increased in Korea peninsula with the sea on three side. The system will be more fully equipped to deal with disasters linked to communication so alone sailing ship is at sea. Research is needed on communication links to submarines operated by submarine to sink a ship, as well as immersion in the sea with. And it is necessary in the study of the land in preparation for the emergency disaster ship and submarine communication links for offshore and subsea oil and associated communication systems. Will be studied in preparation for the communication protocols and emergency and disaster location and land the plane or for a career in the satellite systems are linked through this. It is necessary for this purpose is research on the integrated emergency disaster communication ecosystem.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.1
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• pp.44-49
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• 2020

Recently, one of the major issues of shipbuilding and marine is the reduction of air and marine pollution emission to ships. In response, the International Maritime Organization (IMO) has concluded an international convention (MARPOL) to prevent pollution from ships. A Annex Six of The Convention restricts and regulates air and marine pollution of ship from exhausting gases. To this end, it is required to apply EEDI (Energy Efficiency Design Indicators) to the construction of new ships, and to minimize the emission of environmental pollutants by recommending the application of EEOI (Energy Efficiency Operation Indicators) to operational ships. Therefore, in this study, we propose to calculate the grade of operating efficiency (EG) of ships based on actual operational data for transport ships and to provide energy-efficient optimal path search information through analysis of marine environment data.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.1-12
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• 2021

The International Maritime Organization (IMO) is promoting the introduction of e-Navigation that prevents maritime accidents by fusion of Information & Communication Technology (ICT) with ship operation technology. In Korea, Korean e-Navigation is also being developed for fishing vessels and small vessels sailing offshore, which are vulnerable to maritime accidents. However, for the successful development of Korean e-Navigation, it is necessary to develop an indicator that can evaluate the development performance so that the development performance that has been progressed so far can be evaluated and the development direction can be re-established. Therefore, this study attempted to develop an evaluation index tailored to the development goal of e-Navigation service centering on the collision accident, which is a major maritime accident. In this study, a collision accident evaluation index for e-Navigation service was developed by deriving and quantifying the root cause of maritime collision accidents using Root cause analysis(RCA) and fault tree analysis (FTA) techniques. This indicator is considered to be helpful in reducing maritime accidents as it is used as a development indicator for e-Navigation and an indicator for maritime collision accident analysis.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.7
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• pp.767-776
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• 2020

Due to the recent climate change caused by global warming, weather changes in a different pattern from the past have occurred, and the increase in seawater temperature has led to an increase in the size and intensity of typhoons. Accordingly, there is an increasing need for bitts that can be used to secure mooring safety of the ship when a sudden gust occurs. Based on 12 scenarios of a mooring safety evaluation program, this study analyzed the criteria for arranging bollard and bitt, and analyzed the sensitivity of mooring safety when using storm bitts. As a result of the evaluation, it was analyzed that the mooring factor value decreased compared to the general mooring line arrangement when the fore and stern breastline were added to the bitts for gusts. The results of this study can be used as basic data for proposing storm bitts arrangements for gusts in consideration of the characteristics of berth ships and ports. From the perspective of ship operators, storm bitts at the pier will be an effective method for securing the ship's mooring safety in case of a gust of wind.

• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.613-619
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• 2020

Hybrid media access control (MAC) is used in internet of things (IoT) network, because of communication feature concern with data capacity and communication interval between gateway and sensor nodes and the cost efficiency. Hybrid MAC consists of TDMA and CSMA generally. The distance between gateway and sensor node is openly changed in marine IoT network. Therefore, it is needed to control the period of timeslot of hybrid MAC used in marine IoT network. In this paper, the design rule of TDMA timeslot with the variable period depending on communication distance was proposed. It was confirmed from the analysis that 72 times communication between gateway and sensor nodes is possible in LoRa network by using the proposed TDMA variable timeslot scheme.

• Journal of Advanced Navigation Technology
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• v.25 no.1
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• pp.84-89
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• 2021

The alternative method for symmetric configuration in optical link consisted of dispersion management and optical phase conjugation for compensating of the distorted optical signals due to chromatic dispersion and nonlinear effects of standard single mode fiber is proposed. The symmetric configuration means number of fiber spans, dispersion distribution in former half section and latter half section, etc should be symmetrical about optical phase conjugator. In dispersion-managed proposed in this research, optical phase conjugator is located after former half section consisted of 6 fiber spans and before latter half section of 14 fiber spans, and the averaged residual dispersion per span (RDPS) of each half section are consistence. The compensation effects of the distorted signals in the proposed link is analyzed by comparing with the results obtained in dispersion-managed link with the unequally averaged RDPS of each half section. From the simulation results, it is confirmed that RDPS deviation between adjacent fiber span has a grater effect on the compensation than the equivalent of the averaged RDPS.