• Journal of the Korean Society of Marine Environment & Safety
• /
• v.23 no.7
• /
• pp.941-947
• /
• 2017

Increasing marine transportation of dangerous goods using containers causes fire accidents on ships due to leakage of dangerous materials. In IMO (MSC.93), all vessels that are to be loaded five or more containers on weather deck area after 1 January 2016 are required to have a fire extinguishing system called Water Mist Lance (WML) on board. In this study, numerical analysis is performed to design WML with optimal edge radius of curvature using LS-DYNA. The analysis results for the three models with 10 mm, 15 mm and 20 mm lengths of the edge part showed that the only model with 15 mm length penetrated the wall of the container and did not cause damage to the edge of the WML. In the future, based on the results of this study, we will make a WML of prototype and conduct a performance test. And we will continue to improve the problems.

• Journal of Navigation and Port Research
• /
• v.48 no.3
• /
• pp.214-220
• /
• 2024

Remote control is used for operating maritime autonomous surface ships. The operator controls the ship using control data generated by the remote control system. To ensure successful remote control, three principles must be followed: safety, reliability, and availability. To achieve this, the suitability of both the control data and operators for remote control must be established. Currently, there are no international regulations in place for evaluating remote control suitability through experiments on actual ships. Conducting such experiments is dangerous, costly, and time-consuming. The goal of this study is to develop a suitability evaluation method using the output values of control devices used in actual ship operation. The proposed method involves evaluating the suitability of data by analyzing the output values and evaluating the suitability of operators by examining their tracking of these output values. The experiment was conducted using a shore-based remote control system to operate the training ship 'Hannara' of Korea National Maritime and Ocean University. The experiment involved an iterative process of obtaining the operator's tracking value for the output value of the ship's control devices and transmitting and receiving tracking data between the ship and the shore. The evaluation results showed that the transmission and reception performance of control data was suitable for remote operation. However, the operator's tracking performance revealed a need for further education and training. Therefore, the proposed evaluation method can be applied to assess the suitability and analyze both the control data and the operator's compliance with the three principles of remote control.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.29 no.1
• /
• pp.197-204
• /
• 2005

Recently, many ships such as VLCCs, dangerous cargo ships, high speed ferry boats are visiting Yeosu ${\cdot}$ Gwangyang harbor. The traffic volume of the year 2003 has increased as many as 2.5 times of 1988. However there is no suitable ship's routeing system which takes account of today's traffic situations in this area. This study aims at the setting of hazardous factors to mitigate the danger to vessels in Yeosu ${\cdot}$ Gwangyang bay and to secure the safety of maritime environment.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.22 no.1
• /
• pp.52-58
• /
• 2016

In this study we collected various substance codes, physical and chemical properties, and hazard level of the 545 HNS which was determined earlier, and constructed the Korean HNS database including International Maritime Dangerous Goods (IMDG) codes,, informations of explosive and corrosive characteristics of HNS after reviewing of US, Japan and European Database. And also problems of present HNS Database which focused mainly on land-based environment and an absence of information for chemical and physical properties of mixed substance HNS are reported. For the efficient implementation of comprehensive HNS management system, we constructed the basic model for the HNS database in marine environment and made suggestions for improvement for the future development of HNS Database to be prepared for the marine spill accidents.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.10
• /
• pp.1298-1304
• /
• 2019

Since the 9·11 terror attack in 2001, the Maritime Logistics Security System has been strengthened and required X-ray image for every imported cargos from manufacturing countries to United States. For scanning cargos, the container inspection systems use high energy X-rays for examination of contents of a container to check the nuclear, explosive, dangerous and illegal materials. Nowadays, the X-ray cargo scanners are established and used by global technologies for inspection of suspected cargos in the customs agency but these technologies have not been localized and developed sufficiently. In this paper, we propose the X-ray array detector system which is a core component of the container scanning system. For implementation of X-ray array detector, the analog and digital signal processing units are fabricated with integrated hardware, FPGA logics and GUI software for real-time X-ray images. The implemented system is superior in terms of resolution and power consumption compared to the existing products currently used in ports.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.1
• /
• pp.39-46
• /
• 2022

Piracy cases have been increasing globally since 2007. Recently, the waters of West Africa including the Gulf of Guinea, emerged as the most dangerous areas in the world. To prevent piracy damage to ships and crew, the Korean government amended the Piracy Damage Prevention Act on August 17, 2021 to newly define the risk area and the high-risk area for piracy. It also established the legal framework for restricting the entry of ships into such high-risk areas. This study aims to discuss and present a plan for establishing risk areas and high-risk areas for piracy to be noticed by the government in accordance with the amended Act. In this study, international piracy trends, international response measures and the status of international high-risk areas were investigated and analyzed, the matters to be considered to designate high-risk areas were identified. It is expected that the resulting information on high-risk areas for piracy can be utilized not only for the development of government policies on the prevention of piracy, but also as basic academic data.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.16 no.2
• /
• pp.692-712
• /
• 2022

Buoys used for Aid to Navigation systems are widely used to guide the sea paths and are powered by batteries, requiring continuous battery replacement. However, since human labor is required to replace the batteries, humans can be exposed to dangerous situation, including even collision with shipping vessels. In addition, Maritime sensors are installed on the route signs, so that these are often damaged by collisions with small and medium-sized ships, resulting in significant financial loss. In order to prevent these accidents, maritime object detection technology is essential to alert ships approaching buoys. Existing studies apply a number of filters to eliminate noise and to detect objects within the sea image. For this process, most studies directly access the pixels and process the images. However, this approach typically takes a long time to process because of its complexity and the requirements of significant amounts of computational power. In an emergent situation, it is important to alarm the vessel's rapid approach to buoys in real time to avoid collisions between vessels and route signs, therefore minimizing computation and speeding up processes are critical operations. Therefore, we propose Fast Connected Component Labeling (FCCL) which can reduce computation to minimize the processing time of filter applications, while maintaining the detection performance of existing methods. The results show that the detection performance of the FCCL is close to 30 FPS - approximately 2-5 times faster, when compared to the existing methods - while the average throughput is the same as existing methods.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.14 no.1
• /
• pp.71-76
• /
• 2008

The main ports of Korean south sea are exposed to intensive danger as 58.1% of total vessel in Korea waters and 62.9% of total dangerous cargo ships. Therefore, it is required to establish fundamental database to solve numerous issues at the main ports cf the south sea as studying amount of the vessel traffic and their flows into the main ports, and evaluating degree of danger by traffics environmental stress model as analyzing relationships among degree of danger, maritime accident, and number of vessel arriving or departing in the main ports.

• Journal of Navigation and Port Research
• /
• v.30 no.2
• /
• pp.125-130
• /
• 2006

Waves, which are the main source of ship motions in a seaway, considerably affect the performance of a ship. The study of waves and their impact on ship motions within harbors is an important aspect of the design and operation of harbors. The prediction of incoming groups of waves is particularly important for evaluating ship motion within a harbor. Such a prediction makes it possible to evaluate ship safety more accurately. The wave transformation model reported here is applied to actual ports based on Boussinesq wave equations both non-linear and dispersive wave processes be considered in order to capture physical effects such as wave shoaling, refractions, reflection and diffraction in variable depth environments. The prediction of incoming groups of waves is particularly important for evaluating ship motion within a harbor, Such a prediction makes it possible to evaluate ship safety more accurately and provide safe wave informations for navigation. Furthermore, a wave information support system is proposed for entering ships as one technique for improving the safety of ship operations. This system predicts the run of waves and reduces the danger by identifying the most dangerous point near the harbor entrance at the small wave groups.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.12
• /
• pp.1208-1216
• /
• 2007

Turbomachinery such as turbines, pumps and compressors, which are installed in transportation systems, including aircrafts, ships, and space vehicles, etc., often perform crucial missions and are exposed to potential dangerous impact environments such as base-transferred shock forces. To protect turbomachinery from excessive shock forces, it may be needed to accurately analyze transient responses of their rotors, considering the dynamics of mount designs to be applied. In this study a generalized FE transient response analysis model, introducing relative displacements, is proposed to accurately predict transient responses of a flexible rotor-bearing system with mount systems to base-transferred shock forces. In the transient analyses the state-space Newmark method of a direct time integration scheme is utilized, which is based on the average velocity concept. Results show that for the identical mount systems considered, the proposed FE-based detailed flexible rotor model yields more reduced transient vibration responses to the same shocks than a conventional simple model, obtained by treating a rotor as concentrated lumped mass, equivalent spring and a damper or Jeffcott rotor model. Hence, in order to design a rotor-bearing system with a more compact light-weighted mount system, preparing against any potential excessive shock, the proposed FE transient response analysis model herein is recommended.