• Journal of Positioning, Navigation, and Timing
• /
• v.11 no.4
• /
• pp.229-238
• /
• 2022

This paper addresses on the International technical trends, standards, and development status of terrestrial radionavigation system to provide more accurate and fail-safe Positioning, Navigation, and Timing (PNT) Information available in maritime navigation environment. We analyze the performance result of pilot service in enhanced Long range navigation (eLoran) testbed environment using Low Frequency (LF) signal, and describe the development status of Ranging-Mode (R-Mode) system using Medium Frequency (MF) and Very High Frequency (VHF) to meet the Harbor Entrances and Approaches (HEA) requirement of International Maritime Organization (IMO) within 10m position accuracy. Furthermore, we present an architecture for integrated service of satellite-terrestrial navigation system and future maritime applicable fields. As the core information infrastructure of future navigation for 4th industrial revolution, this paper will be contributed to determining the direction of present and future to provide fail-safe PNT service with Global Navigation Satellite System (GNSS) based on the technical enhancement of terrestrial integrated navigation system.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.2 no.1
• /
• pp.121-123
• /
• 1996

Technical developments, particularly in communications, increase the potential for effective maritime search and rescue(SAR). The paper identifies some of the questions those seeking to proveid effective SAR service should ask, and outlines possible answers.

• Journal of Navigation and Port Research
• /
• v.46 no.6
• /
• pp.501-508
• /
• 2022

The flow of global digitalization is leading to the emergence of a decentralized system environment based on blockchain or distributed ledger technology in the fields of economy, identity authentication, and logistics. Accordingly, a requirement that public services be searchable from several decentralized maritime service registries (MSRs) has been derived in terms of the discoverability of e-navigation services. This study describes a decentralized MSR environment composed of the MSR ledger and multiple local MSRs, and it has implemented a service search system that can search global e-navigation services in the environment through a web browser. This system is a decentralized application that dynamically generates service attributes, geometry information, and free text queries, and that provides users with relevant MSR and service access information from search results that are registered in the MSR ledger. In this study, we tested the established decentralized MSR environment and the system that performs service search within that environment, and we discussed its advantages and limitations.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.21 no.3
• /
• pp.246-252
• /
• 2015

This paper compared the consistency of the Environment Stress(ES) model and the Potential Risk Assessment Model (PARK model, which was developed based on a Korean mariner risk perception) for the Busan adjacent waterway. Evaluation of accuracy and comparison of these two models have been made by Vessel Traffic Service (VTS) officers in the Busan VTS Centre. The assessment results of Busan waterway show that the PARK model is more consistent than the ES model as follows. (1) The difference between assessment results applying ES model and PARK model with risk degree of VTSOs were 34% and 5% respectively in six typical traffic situations. (2) The assessment using PARK model is more suitable and identical with the VTSOs opinion in his or her duty time.

• Journal of Advanced Navigation Technology
• /
• v.22 no.6
• /
• pp.514-521
• /
• 2018

COSPAS-SARSAT 406 MHz emergency beacons include ELTs for aviation, EPIRBs for maritime, and PLBs for individuals in distress. They are used to sending messages encoded on 406 MHzdistress frequency and sending alertsfor search and rescue in distress. C/S T.001 and T.018 are COSPAS-SARSAT technical documents. They include basic technical information needed for developing beacons, howmessages are constructed, and test methods for type approval. COSPAS-SARSAT systems that use existing low earth orbit (LEO) and geostationary earth orbit (GEO) satellites do not have a return link service (RLS). So, the survivors could not confirm whether the distress signal was sending or not. However, a new medium earth orbit (MEO)satellite system has been added to thissystem, allowing confirmation through the RLS function. This paper analyzed C/S T.001 and T.018 needed to develop navigation structuresthat incorporated improved PLB of 406 MHz, a homing signal generator of 121.5 MHz, and a VHF AM transmitter for aviation of 243 MHz.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39C no.7
• /
• pp.582-588
• /
• 2014

IMO and IALA have undertaken projects that GMDSS Modernization and E-navigation, which refer to "Future digital communications systems" for a more efficient transmission of voice and data communications in the VHF maritime mobile service. ITU has also resolved in WRC-07 Resolution 357 to study the use of spectrum-efficient technologies in order to provide for the operation of ship and port security and maritime safety systems. IALA and ITU WP5B have coordinated for the technical developments and the spectrum issues. Recommendation ITU-R M.1842-1 has approved by WP5B meeting. This revision provides a wideband data service both 50kHz and 100kHz in the VHF maritime mobile service. This paper has studied E-navigation, its needs for data exchange that includes explanations of the current methods for transmitting data by VHF that based in land mobile radio service. A further technologies trend is estimated for Recommendation ITU-R M.1842-1, that is based on the land mobile radio standards with some tailored to fit the needs of the maritime mobile service.

• Journal of Positioning, Navigation, and Timing
• /
• v.11 no.4
• /
• pp.279-286
• /
• 2022

In this paper, we designed a software library that produces integrated Global Navigation Satellite System (GNSS) / Inertial Navigation System (INS) navigation information using the raw measurements provided by the GNSS chipset, gyroscope, accelerometer and magnetometer embedded in android smartphone. Loosely coupled integration method was used to derive information of GNSS /INS integrated navigation. An application built in the designed library was developed and installed on the android smartphone. And we conducted field experiments. GNSS navigation messages were collected in the Radio Technical Commission for Maritime Service (RTCM 3.0) format by the Network Transport of RTCM via Internet Protocol (NTRIP). As a result of experiments, it was confirmed that design requirements were satisfied by deriving navigation such as three-dimensional position and speed, course over ground (COG), speed over ground (SOG), heading and protection level (PL) using the designed library. In addition, the results of this experiment are expected to be applicable to maritime navigation applications using smart device.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.6
• /
• pp.1002-1012
• /
• 2022

As the fourth industrial revolution (Industry 4.0) evolves, studies on autonomous ships have been conducting in the shipping industry. Currently, two or three degrees of autonomous ships is in operation, and a shore remote control of icer (SRCO) monitors vessel operations and intervenes remotely where necessary in the service. However, as the curriculum for an SRCO has not been established internationally, the risk of an accident by an unqualified SRCO is increasing. In this study, specifies the curriculum required for SRCO that consists of suitable existing training and new training under remote control circumstances. This includes Non-technical skill training to enhance the effectiveness of an SRCO. This curriculum can be used for a new SRCO to evaluate training and competency specific safety standards, and to enable existing seafarers to become SRCOs through the necessary training.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2021.11a
• /
• pp.201-202
• /
• 2021

Regulations on greenhouse gases emitted from ships in international shipping are being strengthened, and the greenhouse gas reduction target established by the International Maritime Organization is acting as a great challenge for shipping companies in terms of technical and operational aspects. The International Maritime Organization aims to reduce carbon intensity by 30% by 2030, 70% by 2050, and by 50% in terms of gross emissions compared to 2008. To realize this situation, the IMO adopted some short-term and mid-to-long-term measures and adopted technical measures such as the application of EEXI, an energy efficiency index, to existing ships from 2023, and the early application of EEDI phase 3 for some tpe of ships. In addition, reduction measures were introduced to reduce greenhouse gas in the operational aspect.

• Journal of the Society of Naval Architects of Korea
• /
• v.42 no.3
• /
• pp.259-267
• /
• 2005

The effects of hull flexibility on shaft alignment are growing as ship sizes are increased mainly for container carrier and LNG carrier. In order to consider hull flexibility on a propulsion shafting system, standardization of ship service conditions is necessary because hull deformation is continuously variable according to ship service conditions. How to summarize ship service conditions is suggested based on practically applicable four viewpoints : hull, engine, loading and sea status. Effects of the external forces acting on a ship propulsion shafting system are generally commented. Several design criteria regulated by classification societies are pointed at issue which seems to have Insufficient technical background. A qualitative verification is carried out to point out the invalidity of the assumption of effective supporting position. In this work, an elastic nonlinear multi-supporting bearing system is introduced as a key concept of the elastic shaft alignment. Hertz contact theory is proved to be more proper one than projected area method in calculation of the nonlinear elastic stiffness of the bearing, The squeezing and oil film pressure calculations in the long journal bearing like an after stern tube bearing are recognized as a necessary process for elastic shaft alignment design.