• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.2A
• /
• pp.139-148
• /
• 2011

This paper presents the minimum-cost network selection scheme which determines the transmission instance in the multi-band maritime communication system, so that the shipment-related real-time information can be transmitted within the maximum allowed period. The transmission instances and the corresponding network selection process are modeled by a Markov Decision Process (MDP), for the channel model in the 2-state Markov chain, which can be solved by stochastic dynamic programming. It derives the minimum-cost network selection rule, which can reduce the network cost significantly as compared with the straight-forward scheme with a periodic transmission.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.05a
• /
• pp.652-655
• /
• 2017

As maritime information and communication technology has been developing and the demands for various kinds of application services has been increasing nowadays, the multi-band maritime networks combining available multiple radio networks has been introduced. We have previously proposed a multi-band network selection(MNS) system which operates in the middleware layer and selects the best available network seamlessly. In this paper we develop MNS server software, network interfaces, and application program. The functionalities of the MNS system, including updating network status, connecting to heterogeneous networks, and communicating in the best network are also verified via indoor test.

• ETRI Journal
• /
• v.43 no.1
• /
• pp.74-81
• /
• 2021

The mixture model is a very powerful and flexible tool in clustering analysis. Based on the Dirichlet process and parsimonious Gaussian distribution, we propose a new nonparametric mixture framework for solving challenging clustering problems. Meanwhile, the inference of the model depends on the efficient online variational Bayesian approach, which enhances the information exchange between the whole and the part to a certain extent and applies to scalable datasets. The experiments on the scene database indicate that the novel clustering framework, when combined with a convolutional neural network for feature extraction, has meaningful advantages over other models.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2002.05a
• /
• pp.647-652
• /
• 2002

The main object of Maritime Safety Network is to prevent Marine Accidents in advance and avoid the loss of live and property efficiently. Our country's Marine Safety Network was widely changed with its concerned rules and the operation methods through the complete operation of GMDSS system. Thus, compared with the past, maritime safety equipment and its systems were enforced, but the loss of lives from marine accidents tends to increase against the general expectation. 80 percent of the total marine accidents in Korea is caused by small fishing boats that are capsized immediately from accidents. To minimize the loss of lives they are to require the help of rescue. Lately imported GMDSS communication equipment is operated very fast automatically to issue the rescue and inform the distress, but most general small fishing boats are under 5 ton vessel and excluded from the administration of GMDSS system. In this paper is to propose the proper solution for the efficient improvement of maritime safety network suitable for the our practical circumstance.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.10
• /
• pp.2097-2104
• /
• 2009

In terrestrial communications, high data rate transmission can be achieved by splitting the coverage area into small cells through base stations and reusing the resource efficiently. However, the geographical features of maritime communications require the long transmission range, and it is not practical to install base station on the sea to set up the similar deployment as the terrestrial communications, so MF/HF band modem with low data rate are currently utilized for maritime communications. And the expensive satellite communication via Inmarsat is the conventional solution for the high data rate transmission on the sea. To reduce the cost, Ad-hoc network is proposed to apply on the sea, which requires no base station for the peer-to-peer communications. In this paper, we denominate this maritime environment specific Ad-hoc network as Nautical Ad-hoc Network (NANET). Furthermore, the deployment scenario for the NANET, and the analysis on multiple access and duplexing schemes for the NANET are discussed in this paper, which serves as the cornerstone for the further NANET research and development.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2019.05a
• /
• pp.418-420
• /
• 2019

Sensor node and edge device for multi-sensing of marine IoT service is proposed. Especially, the proposed devices are based on the management and data process through the closed network (i.e., private network) as well as the commercial public network provided by major communication service providers.

• International Journal of Computer Science & Network Security
• /
• v.23 no.1
• /
• pp.64-70
• /
• 2023

Maritime transport is dominant in the overall volume of all international transportation. Existence and overcoming of problems, which cause pressure on shipping safety, remain actual and fully concern both maritime and inland transport. Increasing speed and cargo capacity of the ships along with the reduction of crew members lead to the automation of a growing number of work processes, which indicates the need to actively introduce appropriate measures in the security system of sea-going ships and commercial ports and to develop modern approaches to minimize negative events and incidents in the process of ship operation. Advantages in use of modern methods of monitoring the safety of ship operations, management of possible events and incidents, including investigation of accidents, first, aimed at prevention of negative occurrences and ways of prevention on this basis. Considering statistics on incidents increase, this work presents analysis of general ship accident rate, study of major accidental events growth annually, and investigation of causes of incidents, which most frequently occur in port waters and at open sea. A survey of current approaches to ensuring the safety of shipping by implementing effective tools, such as event and incident management, has been conducted.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.18 no.6
• /
• pp.1659-1674
• /
• 2024

Conventional maritime communication struggles to provide high data rate services for Internet of Things (IoT) devices due to the variability of maritime environments, making it challenging to ensure consistent connectivity for onboard sensors and devices. To resolve this, we perform mathematical modeling of the maritime channel and compare it with real measurement data. Through the modeled channel, we verify the received beam gain at buoys on the ocean surface. Additionally, leveraging the modeled wave motions, we estimate future angles of the buoy to use the Extended Kalman Filter (EKF) for design beamforming strategies that adapt to the evolving maritime environment over time. We further validate the effectiveness of these strategies by assessing the results from an outage probability perspective. focuses on improving maritime communication by developing a dynamic model of the maritime channel and implementing a Kalman filter-based buoy motion tracking system. This system is designed to enable precise beamforming, a technique used to direct communication signals more accurately. By improving beamforming, the aim is to enhance the quality of communication links, even in challenging maritime conditions like rough seas and varying sea states. In our simulations that consider realistic wave motions, you've observed significant improvements in link quality due to the enhanced beamforming technique. These improvements are particularly notable in environments with high sea states, where communication challenges are typically more pronounced. The progress made in this area is not just a technical achievement; it has broad implications for the future of maritime communication technologies. This paper promises to revolutionize the way we approach communication in maritime environments, paving the way for more reliable and efficient information exchange on the seas.

• Journal of the Society of Disaster Information
• /
• v.3 no.2
• /
• pp.79-93
• /
• 2007

With international urgence of terror situation, many methods of terror techniques and skills are appearing and more intense and threatening terror is braking out not only in the air(plane), but also in the sea(ship). Korea is surrounded by 3 sides of sea and is a proud maritime nation that should advance to foreign country through the sea because South Korea and North Korea are confronting. Korea depend on the maritime transportation, 99.7% of exporting, importing material resources. Therefore, acquisition of the marine safety has the great affect on national security and economical life. On the high tension of situation about threat and possibility of maritime terroism, the potential ways of the improvement policy for counter-tactics against big maritime terror are the following. First, we should construct clear and well-organized network for accurate information about maritime terrorism Second, we should have the information of all domestic, foreign passenger's ships Third, national important facilities such as atomic energy plant, thermo-electric power plant, shipyard need policies to manage all emergency situation Fourth, government authorities should improve tactic abilitities by competing with support and budget inside of nation as well as outside of nation. To develop big maritime terror of our country, we will have to hold cooperative training & tactics contest of big maritime terror by cooperating educational industry organization with similar institute, improve the ability of members of big terror and acquire tactics information by excavating and exchanging a new technique through tactics seminar and public hearing.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.4
• /
• pp.515-524
• /
• 2022

To effectively collect, manage, and share the maritime traffic information, it is necessary to identify the technology trends concerning this particular information and analyze its current status and problems. Therefore, this study observes the domestic and foreign technology trends involving maritime traffic information while analyzing and summarizing the current status and problems in collecting, managing, and sharing it. According to the data analysis, the problems in the collecting stage are difficulties in collecting visual information from long-distance radars, CCTVs, and cameras in areas outside the LTE network coverage. Notably, this explains the challenges in detecting smuggling ships entering the territorial waters through the exclusive economic zone (EEZ) in the early stage. The problems in the management stage include difficult reductions and expansions of maritime traffic information caused by the lack of flexibility in storage spaces mostly constructed by the maritime transportation system. Additionally, it is challenging to deal with system failure with system redundancy and backup as a countermeasure. Furthermore, the problems in the sharing stage show that it is difficult to share information with external operating organizations since the internal network is mainly used to share maritime transportation information. If at all through the government cloud via platforms such as LRIT and SASS, it often fails to effectively provide various S/W applications that help use maritime big data. Therefore, it is suggested that collecting equipment such as unmanned aerial vehicles and satellites should be constructed to expand collecting areas in the collecting stage. In the management and sharing stages, the introduction and construction of private clouds are suggested, considering the operational administration and information disclosure of each maritime transportation system. Through these efforts, an enhancement of the expertise and security of clouds is expected.