• International Journal of Internet, Broadcasting and Communication
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• v.16 no.3
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• pp.221-227
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• 2024

In autonomous navigation systems, the need for fast and accurate image processing using deep learning and advanced sensor technologies is paramount. These systems rely heavily on the ability to process and interpret visual data swiftly and precisely to ensure safe and efficient navigation. Despite the critical importance of such capabilities, there has been a noticeable lack of research specifically focused on ship image classification for maritime applications. This gap highlights the necessity for more in-depth studies in this domain. In this paper, we aim to address this gap by presenting a comprehensive comparative study of ship image classification using two distinct neural network models: the Feedforward Neural Network (FNN) and the Convolutional Neural Network (CNN). Our study involves the application of both models to the task of classifying ship images, utilizing a dataset specifically prepared for this purpose. Through our analysis, we found that the Convolutional Neural Network demonstrates significantly more effective performance in accurately classifying ship images compared to the Feedforward Neural Network. The findings from this research are significant as they can contribute to the advancement of core source technologies for maritime autonomous navigation systems. By leveraging the superior image classification capabilities of convolutional neural networks, we can enhance the accuracy and reliability of these systems. This improvement is crucial for the development of more efficient and safer autonomous maritime operations, ultimately contributing to the broader field of autonomous transportation technology.

• Journal of Advanced Navigation Technology
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• v.21 no.4
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• pp.332-338
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• 2017

Launch and recovery system(LARS) is required to perform an USV-based underwater exploration. Through the analysis of the requirements according to the scenario of underwater exploration, the mechanism of LARS and the conceptual design of the mechanical parts of LARS are carried out. In addition, a USV motion can be induced due to environmental disturbances such as waves, so the detailed design of LARS for recovering the underwater tow-fish stably in consideration of the USV motion is performed. To verify the performance of launch and recovery operations, LARS and test bed were developed. The results show that the proposed LARS can stably launch and recovery an underwater tow-fish.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.4
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• pp.385-392
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• 2009

Maritime safety management needs active public participations because the sea is too wide for a government to respond to all unexpected accidents with limited resources. Marine rescue volunteer organizations of US, UK, Japan and Korea were compared one another on the base of disaster management governance theory, and recommendations for the development of marine rescue volunteer organization of Korea were proposed. The advanced organizations commonly have tradition of marine rescue voluntaryism in the advanced maritime countries. They have nation-wide networks and self-governing structures. Their main activities include public maritime safety education and fundraising programs as well as marine rescue operations. They have cooperative relationships with government agencies in charge of national maritime safety management, which are usually guaranteed by legislations or institutional systems. Donations from the public are major source of their finances. Members mainly consist of civil volunteers, and get basic compensations for their expenses. For the advancement of marine rescue volunteer organization of Korea, efforts are needed to strengthen the membership of civil rescue fleet, to activate public education and fundraising programs, and to amend the related law for institutional support.

• Strategy21
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• s.39
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• pp.163-197
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• 2016

The completion of Jeju Naval Base on February 2016 made the Republic of Korea Navy(ROKN) review the size and role of the Maritime Task Flotilla(MTF). The new strategic environment for the 12st century and the new challenges require the Navy to counter North Korea's provocations and prevent potential enemy's threat. The Navy is also required to take part in the variety of international roles and missions commensurated with Korea's global status to maximize the national interest. Despite these changes, Korea's military construction concept is still unable to break away from the old paradigm of the North Korean threat largely centered. In order to develop the current MTF into the Task Group with the construction of Jeju Naval Base, the Navy must newly not only establish new force development plan and fleet management concepts but also go to persuade and convince policy decision makers. To this end, the following efforts should be promoted. First, the ROK Navy steps up efforts in order to share with the Task Group's vision and strategy. The Navy should also provide the size and structure as well as the missions and roles of the Task Group to react to new maritime security environment. Second, the Navy analyse the MTF's ability and what is required and necessary to perform its duty. After that, it must set out the direction of the Task Group's force development. Third, the current missions and roles of the MTF should be re-established to respond various threats. Finally, accommodating of new technology to the MTF should intensify its strengths. The ROK Navy has a mixed force structure consisting of three fixed- base fleets and a MTF. The fixed base fleet has a passive force to defend and protect its own sea areas, but the MTF should actively not only counter North Korea's threats, including ballistic missiles, but also fight potential threats and takes international missions as a primary task force. However, the MTF has a limited capability to accomplish given missions and long-range operations, and thus, the ROK Navy is strongly required to construct the Task Group.

• Strategy21
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• s.43
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• pp.125-174
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• 2018

The purpose of this paper is to analyze the status of naval arms race in Northeast Asia. To this end, the scope of the research was limited to national security strategies, maritime strategies and naval strengthening of the United States, China, Russia and Japan. The major powers' active maritime strategies and naval arms race give some strategic implications to the Republic of Korea Navy as follows. First, China and Japan, unlike the past, are actively using submarines in offshore waters including the Korean Peninsula. Therefore, the ROK Navy must successfully promote the Jangbogo-III-class submarine, which is currently constructed, and get a nuclear-powered submarine and P-8 MPA capable of long-range and long-time operations to enhance ASW capability. Second, North Korea's current building submarines capable of loading SLBMs and SLBMs are a new threat to the ROK Navy. The current building KAMD, which focuses on terminal phase defense, cannot effectively respond to North Korea's SLBMs and should be converted to a multi-layered defense system including SM-3 at a mid-course phase. Third, as China militarizes the South China Sea, the instability of the South China Sea is growing. Therefore, the ROK Navy should strengthen its maritime cooperation with the regional countries such as Japan and ASEAN navies to protect SLOC. In conclusion, the ROK Navy needs to build a strong naval power to keep in mind that the 21st century naval rivalry in Northeast Asia is accelerating. The navy must do one's best to protect national strategic and vital interests by strengthening cooperation with regional countries. South Korea is also accelerating its defense reforms in accordance with the pattern of future warfare and the ROK Navy do one's best to have a balanced naval capability capable of actively operating in the offshore waters.

• Journal of Navigation and Port Research
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• v.38 no.5
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• pp.541-547
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• 2014

Busan was known firstly to the western world in the end of 18th century. When the Joseon opened a port under the western powers in the late 19th century, Busan was an important port. The increasing number of international ship exchange had magnified the harbor facility and the importance of lighthouses of Busan port. Busan maritime customs officer were in charge of installation and management of lighthouses. The operations of maritime customs became historical origin of Joseon changing from feudal society to modern nation. The majority of the documents from maritime customs was disappeared. So it was hard to know the exact history. But investigating documents and papers of Joseon, even media records will enable us to establish the objective fact relations. Moreover, published and translated data from the past make it possible such investigations. As a result, modern lighthouse of Busan harbor in the late Joseon after opening port was could be found. It could be offered to establishing the Korean modern history as the objective data.

• Journal of the Korea Society of Computer and Information
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• v.27 no.3
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• pp.1-12
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• 2022

In the event of a maritime distress accident, rapid search and rescue operations using rescue assets are very important to ensure the safety and life of drowning person's at sea. In this paper, we analyzed the surface layer current in the northwest sea area of Ulleungdo by applying machine learning such as multiple linear regression, decision tree, support vector machine, vector autoregression, and LSTM to the meteorological information collected from the maritime observation buoy. And we predicted the drowning person's route at sea based on the predicted current direction and speed information by constructing each prediction model. Comparing the various machine learning models applied in this paper through the performance evaluation measures of MAE and RMSE, the LSTM model is the best. In addition, LSTM model showed superior performance compared to the other models in the view of the difference distance between the actual and predicted movement point of drowning person.

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

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.88-96
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• 2021

When oil tankers, large passenger ships and cargo ships sink under the sea owing to various maritime accidents, the residual cargo oil or fuel oil in the such vessels could pose direct risk to factor for the marine environment and it require safe and rapid removal. Although domestic and foreign salvage companies are adopting various recovery methods and technologies with customizations according to each site during recovery operations studies on reasonable assessment modules for the operation process are relatively insufficient. In this study, the data from trapped-oil recovery operations performed at different site conditions were collected and analyzed in order to designed an operation assessment module, define the operational process steps in terms of preparation, implementation and completion, and derive key factors for each detailed process. Subsequently, the module was designed in such a way as to construct performance indicators to assess these key factors. In order to exclude subjective opinions from the assessment as much as possible, the assessment each item was constructed with indicators based on data that could be evaluated quantitatively and its usefulness was verified by applying the module to the trapped-oil recovery operation cases. We expect this the method and the technology assessment module for the trapped-oil recovery operation on sunken vessels will help to verify the adequacy of the trapped-oil recovery such operation before or after. Furthermore, it is expected that the continuous accumulation of assessment data and feedback from past or future operation cases will contribute toward enhancing the overall safety, efficiency and field applicability of trapped-oil recovery operation.

• Honam Mathematical Journal
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• v.38 no.4
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• pp.833-847
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• 2016

We are interested in the problem of finding the Hausdorff distance between two objects in ${\mathbb{R}}^2$, or in ${\mathbb{R}}^3$. In this paper, we develop an algorithm for computing the Hausdorff distance between two ellipses in ${\mathbb{R}}^3$. Our algorithm is mainly based on computing the distance between a point $u{\in}{\mathbb{R}}^3$ and a standard ellipse $E_s$, equipped with a pruning technique. This algorithm requires O(log M) operations, compared with O(M) operations for a direct method, to achieve a comparable accuracy. We give an example,and observe that the computational cost needed by our algorithm is only O(log M).