• Journal of Korean Port Research
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• v.11 no.2
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• pp.215-230
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• 1997

A number of ocean outfalls are located around coastal area over the United States and discharge primary treated effluent into deep water for efficient wastewater treatment. Two of them, the Sand Island and Honouliuli municipal wastewater outfalls, are located on the south coast of Oahu. There have been growing interests about the plume dynamics around the ocean outfalls since plume discharged from the multiport diffuser may have significant impacts on coastal communities and immediate consequence on public health. Among the studies of plume dynamics performed in the vicinity of both outfalls, Project MB-4 in the Mamala Bay Study recently made with the funding in the $ 9 million amount statistically dealt with the near-field behavior of the plumes at the Sand Island and Honouliuli outfalls. However, Project MB-4 predicted much higher surfacing frequency than the realistic value obtained by model studies by Oceanit Laboratories, Inc.. It is suggested that improvements should be made in the application of the plume model to more simulate the actual discharge characteristics and ocean conditions. In this study, it has been recommended that input parameters in plume models reflect realistic density profile over the entire water column since. in the previous Mamala Bay Study, the density profiles were measured at 5m depth increments extending from 13 to 63 m depth (the density profile on the upper portion of water column was not included, Roberts 1995). It is proved that the density stratification is the important parameter for the submergence of the plume. In this study, as one of the important parameters, plume rise and initial dilution reflecting the density profile over the entire water column have been taken into account for more reliable plume behavior description.

• Korean Security Journal
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• no.32
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• pp.95-122
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• 2012

The ocean in the 21st century is getting emphasized as a treasury of natural resources and a growth engine for the nation. And nations around the world have entered into the hyper-competition to take the initiative for those marine resources. Under the situation, the Korea Coast Guard is devoting itself with full force to protecting maritime sovereignty, ensuring maritime safety and security and preserving the marine environment. Purpose of this study is to analyze Maritime Policing Act of 2012 and their problems and to suggest improvement measures. Objectives of Maritime Policing Act of 2012 is national Defence, policing for maritime security, protection of marine natural resources and marine facility in territorial waters and exclusive economic zone(EEZ) of Korea. Limits of Maritime Policing Act of 2012 are as follows. First, As organization related rules in Maritime Policing Act of 2012 are not enough, Maritime police agency Act should be revised and enacted in order to cope with future administrative demands and legal ground. Second, Article 22 penal regulation is more severe than regulations of another Act. Third, Article 14 should be made improvement for pre-prevention through the pre-report and the establishment of prohibition boundary in maritime demonstration.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.205-208
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• 2015

Large vessels are currently operating by using an ECDIS, a system enabling automatic navigation and checking marine conditions. In the past, the ECDIS was used for vessels but in these days, it has been used as a method for collecting and verifying marine information, etc. from land by using a computer, instead of taking a boat out. The ECDIS on sale is generally used by companies which operate marine workers. However, this system has caused inconvenience to marine workers, in terms of tasks, services, or operations. Marine workers move out to the sea after checking the status of the system at the office. Due to the weather such as waves and winds, marine devices are not often found on the relevant coordinates. In such a case, the workers onerously need to come back to the land and track the marine devices again. In order to solve such a problem, this thesis purposes to develop a system which can check the locations of marine devices and verify a marine chart even on the sea by using a mobile. The proposed system can integrate and support a variety of protocols of relevant devices in the system itself and check data via mobile through the data transmission and streaming functions.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.12
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• pp.1577-1588
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• 2018

Recently, many researches are progressing to support the operation and maintenance works of vessels using analyzed result based on various information of equipment. The interfaces of communication equipment are standardized very well, but the interfaces of machinery and other parts are not standardized yet. For that reason, there has limitations for data exchange and management. To solve the problem, the ISO is establishing new standards which are ISO 19847 for shipboard data servers th share field data at sea and ISO 19848 for standard data for shipboard machinery and equipment. In this paper, we developed a data management platform for shipboard machinery equipment, and tested the field data exchanging using the developed platform based on the standards. To do this, we analyzed the requirements of the standards and related researches, and designed an architecture of shipboard data platform that satisfied the requirements. Also, we developed components of the designed platform architecture and verified the effectiveness for it.

• Maritime Security
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• v.1 no.1
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• pp.311-343
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• 2020

Because of the global warming, the Arctic Ocean is expected to be ice-free by the year 2035. When the Arctic Ocean will be opened, a number of national interests will become more salient as experiencing a shortened sailing distance and decreasing navigation expense, possibility of natural resources transport by sea from Arctic Circle, and indirect-profit making by building a herb port in Asia. To secure the national interests and support the free activities of people in this region, R.O.K government is trying to make advanced policies. In order to carry out the naval tasks in the Arctic Ocean, using the operational characteristics(mobility, flexibility, sustainability, presence of capabilities, projection) is necessary. To this end, ROK Navy should analyze the operational environment (O.E.) by its capability(weakness and strength), opportunity, and threat. R.O.K. Navy should make an effort over the following issues to implement the tasks in the Arctic Ocean: first, Navy needs to map out her own plan (Roadmap) under the direction of government policies and makes crews participate in the education·training programs in home and abroad for future polar experts. Third, to develop the forces and materials for the tasks in cold, far operations area, Navy should use domestic well-experienced shipbuilding skills and techniques of the fourth industrial revolution. Next, improving the combined operations capabilities and military trust with other countries in the Arctic region to cover the large area with lack of forces' number and to resolve the ports of call issues. Lastly, preparation in advance to execute a variety of missions against military and non-traditional threats such as epidemics, HA/DR, SOLAS, in the future operation area is required.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.53-59
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• 2021

The marine transport industry generally applies new technologies later than other transport industries, such as airways and railways. Vessels require efficient operation, and their performance and lifespan depend on the level of maintenance and management. Many studies have shown that corrective maintenance (CM) and time-based maintenance (TBM) have restrictions with respect to enabling efficient maintenance of workload and cost to improve operational efficiency. Predictive maintenance (PdM) is an advanced technology that allows monitoring the condition and performance of a target machine to predict its time of failure and helps maintain the key machinery in optimal working conditions at all times. This study presents the development of a marine predictive maintenance (MPdM; maritime predictive maintenance) method based on applying PdM to the marine environment. The MPdM scheme is designed by considering the special environment of the marine transport industry and the extreme marine conditions. Further, results of the study elaborates upon the concept of MPdM and its necessity to advancing marine transportation in the future.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.1086-1091
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• 2022

The International Maritime Organization is establishing international agreements on maritime safety and security to prepare for the introduction of autonomous ships. In Korea, the industry is focusing on autonomous navigation system technology development, and to reduce accidents involving coastal ships, research on autonomous ship technology application plans for coastal ships is in progress. Interest in autonomously operated ships is increasing worldwide, and maritime demonstrations for verification of developed technologies are being pursued. In this study, a basic investigation was conducted on the design of a demonstration ship and an onshore platform (remote support center) using digital twin technology for application to coastal ships. To apply digital twin technology, an 8-m small battery-powered electric propulsion ship was selected as the target. The basic design of the twin-integrated platform was developed. The ship navigation and operation data were stored on a server system, and remote-control commands of the electric propulsion ship was achieved through communication between the ship and the onshore platform. Ship performance management, operation and operation optimization, and predictive control are possible using this digital twin technology. This safe and economical digital twin technology is applicable to ships responding to crisis scenarios.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.5
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• pp.462-469
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• 2023

In this study, we propose a method for evaluating the risk of collision between ships to support determination on the risk of collision in a situation in which ships encounter each other and to prevent collision accidents. Because several uncertainties are involved in the navigation of a ship, must be considered when evaluating the risk of collision. We apply the Dempster-Shafer theory to manage this uncertainty and evaluate the collision risk of each target vessel in real time. The distance at the closest point approach (DCPA), time to the closest point approach (TCPA), distance from another vessel, relative bearing, and velocity ratio are used as evaluation factors for ship collision risk. The basic probability assignments (BPAs) calculated by membership functions for each evaluation factor are fused through the combination rule of the Dempster-Shafer theory. As a result of the experiment using automatic identification system (AIS) data collected in situations where ships actually encounter each other, the suitability of evaluation was verified. By evaluating the risk of collision in real time in encounter situations between ships, collision accidents caused by human errora can be prevented. This is expected to be used for vessel traffic service systems and collision avoidance systems for autonomous ships.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.27 no.1
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• pp.33-47
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• 2022

In this study, distribution of submarine sand ridges in the coastal waters of Korea was surveyed using multibeam echo sounder data, and the topographic characteristics of each region were identified. For this purpose, the DEM (Digital Elevation Model) data was generated using depth data obtained from the Yellow Sea and the South Sea by Korea Hydrographic and Oceanographic Agency, and then applied the TPI (Topographic Position Index) technique to precisely extract the boundary of the sand ridges. As a result, a total of 200 sand ridges distributed in the coastal waters were identified, and the characteristics of each region of the sedimentary sediments were analyzed by performing statistical analysis on the scale (width, length, perimeter, area, height) and shape (width/length ratio, height/width ratio, linear·branch type, exposure·non-exposure type). The results of this study are expected to be used not only for coastal navigational safety, but also for marine naming support, marine aggregate resource identification, and fisheries resource management.