• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.11
• /
• pp.2562-2568
• /
• 2015

This paper proposes a detection method for irregularity of ionospheric delay in network RTK (Real Time Kinematic) Environment. The linearity of network RTK correction provided to user can't be assured when a characteristic of temporal-spatial of ionospheric delay is rapidly changed due to geomagnetic storm or solar flare. Therefore, incorrect ambiguity can be resolved and positioning error can be increased. A detection method for irregularity of ionospheric delay is needed to provide reliable correction. In this paper, index to detect irregularity of ionospheric delay is calculated from dispersive corrections and occurrence of irregularity is judged by comparing index and thresholds.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.11
• /
• pp.2569-2575
• /
• 2015

Network RTK generally uses a linear interpolation method by using the corrections from reference stations. This minimizes the spatial decorrelation error caused by the increase of distance between the reference station's baseline and user's baseline. However, tropospheric delay, a function of the meteorological data can cause a spatial decorrelation characteristic among reference stations within a network by local meteorological difference. A non-linear characteristic of tropospheric delay can deteriorate Network RTK performance. In this paper, the modeling of tropospheric delay irregularity is made from the data when the typhoon is occurred. By using this modeling, analyzing the effect of meteorological difference between reference stations on correction is performed. Finally, we analyze an effect of non-linear characteristics of tropospheric delay among reference stations to Network RTK user.

• Proceedings of KOSOMES biannual meeting
• /
• 2018.06a
• /
• pp.126-126
• /
• 2018

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.6
• /
• pp.628-638
• /
• 2023

Maritime Autonomous Surface ships(MASS) are gradually gaining importance. Until fully autonomous ships are developed, they will likely be controlled by remote operators who are based in a Remote Operations Center. However, there is currently no internationally or domestically established licensing for them. This issue can potentially pose a risk to navigation safety due to operations being handled by unqualified remote operators. We conducted a literature review and proposed criteria for the adoption of a licensing system for remote operators. We have futher offered alternatives to integrate this license into the existing officer licensing system, and analyzed them using Analytic Hierarchy Process(AHP). Subsequently,, theprimary need to enact legislation for remote operators is observed. The most preferred approach is to include the occupation of a remote operator in the Ship Officer Act, Article 4: Occupational Categories and Class of Licenses. Therefore, it would be logical for the organizational structure of the Remote Operation Center to mirror the traditional Bridge Resource Management. This study will contribute to the efficient training of remote operators and the safe navigation of autonomous ships with a focus on human resource management.

• Journal of Navigation and Port Research
• /
• v.39 no.6
• /
• pp.479-484
• /
• 2015

Network RTK is a precise positioning technique using carrier phase correction data from reference stations within the network, and is constantly being researched for improved performance. However, the study for the system accuracy has been performed but system integrity research has not been done as much as system accuracy, because network RTK has been mainly used on surveying for static or kinematic positioning. In this paper, adequate monitoring system for network RTK is designed as basis research for integrity monitoring on network RTK. To this, fault tree on network RTK is analyzed, and a countermeasure is prepared to detect and identify the each fault items. Based these algorithms, monitoring system to use on central processing facility is designed for network RTK service.

• Journal of the Society of Naval Architects of Korea
• /
• v.54 no.4
• /
• pp.294-300
• /
• 2017

The offshore installations and ships are the structures most likely to be exposed to hazards such as hydrocarbon fire and/or explosion. Developing proactive measures to prevent the escalation of such events thus requires detailed knowledge of the related phenomena and their consequences. $CO_2$ extinguishing systems are extensively used for fire accidents of on-and offshore installations because of outstanding performance and low cost. There is, however, the risk of carbon dioxide system which enumerates many of the fatalities by suffocation associated with industrial fire protection requirements. Therefore, the aim of this study is to perform the prediction of fire suppression characteristics of the carbon dioxide system in realistic enclosed compartment area of ships and propose $CO_2$ extinguish fire fighting system for preventing suffocation accidents during fire fighting. According to CFD calculations, it can be observed and assessed that various fire profiles with $CO_2$ and $O_2$ mole fraction in the target enclosed compartment area are applicable within the proposed system. Additionally, the design of fire safety system of ships and offshore installations can utilize ventilation system and/or layout arrangement through the proposed system.

• Journal of the Society of Naval Architects of Korea
• /
• v.40 no.2
• /
• pp.34-40
• /
• 2003

Ship damage due to maritime casualties lead to marine pollution, loss of life and properties. The maritime casualties come from the rough sea and bad weather condition generally. Therefore the large-scaled casualties will be derived from loss of structural strength and stability due to the progressive flooding and enlargement of damage by the effect of wave and wind. The improvement of damage survivability is very important in maritime safety This paper described the damage survivability assessment system which can be evaluate and improve the ship safety in consideration of loading, sea and damage condition. The components of the system and decision criteria for damage stability and structural safety is established. The ship modeler and behavior analysis program in wave is developed. Finally further research work is also discussed.

• Journal of the Korean Institute of Navigation
• /
• v.18 no.2
• /
• pp.1-18
• /
• 1994

Kwangyang harbour has been developed very rapidly and has 20 berths including 2 for 250,000DWT bulk carriers at the terminal of Kwangyang Steel Company only. In addition to this, the port is developing a container terminal with 10 berths for 50,000GRT container ships, the construction of which is scheduled to be finished in the year 2000. Because of these development, it has been pointed out that the existing waterways are not wide and safe enough for the new large ships to be catered for. This work, therefore, aimed to examine the naviga-tional safety of the waterways of Kwangyang Harbour, and to suggest how to improve the existing water-ways for the large ships to be introduced in the near future. In examining the safety of the existing and newly suggested waterways, waterway design simulation methodology has been applied. From this study, it has been suggested that the No.4 navigational channel has to be dredged to the depth of 22.5 meters and used as an entrance channel only, while the No.3 channel is used as an exit channel. Additionally, a new waterway has been recommended to be established over the Myodo Island for the container ships which will use the new terminal, the width of which has been recommended to be 400 meters with 440 meters from the bend area.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.27 no.1
• /
• pp.74-80
• /
• 2021

When a berth is built close to a fairway, a moored vessel will be affected by the ship waves generated by navigating vessels. In this study, a portable measurement system was developed to measure the roll motion of an actual vessel, and the results were compared with simulation results. The simulation results showed that the roll motion satisfies the loading safety criteria. However, the actual results of the vessel, did not satisfy the criteria in some cases. In this study, 18 cases that did not satisfy the loading safety criteria were analyzed. Among these cases, three cases were affected by a different time zone of the remaining 15 cases, 11 cases (73.3%) were observed to be consistent with arrival times of passenger ships of more than 10,000GT sailing between in Mokpo and Jeju. The results of this study can be used to reflect marine traffic characteristics in the assessment of loading safety, which can increase the reliability of results of the loading safety assessment of ships.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.16 no.3
• /
• pp.146-152
• /
• 2017

Stabilizing the operation of dual fuel diesel engines is very important. The shipbuilding industry is rapidly growing, but gear components requiring reliability are still imported from other countries. The reasoning for this is three-fold. Firstly, it is compulsory that all ships must use devices that meet the performance standards specified in the Safety of Life at Sea (SOLAS) and the convention of MARine POLlution (MAPOL) to prevent pollution caused by ships. Secondly, most ships must comply with the ship classifications specified by ship owners. Therefore, it is specified that key engine gear components must be inspected and authorized for the quality and performance specified by the Ship Register Authority. Thirdly, it is essential that devices (engine gear) for human safety in ships comply with quality standards specified in the regulations and rules by the government. The Ship Register Authority's strict quality standards and approval requirements contribute to the reduction of motivation towards new investment and technology development by device component manufacturers. Therefore, this study aims to develop a method for using infrared thermography to examine gear reliability in order to ensure gear component reliability and national competitiveness in the global market.