• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.843-856
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• 2023

The global surge in maritime traffic has resulted in an increased number of ship collisions, leading to significant economic, environmental, physical, and human damage. The causes of these maritime accidents are multifaceted, often arising from a combination of crew judgment errors, negligence, complexity of navigation routes, weather conditions, and technical deficiencies in the vessels. Given the intricate nuances and contextual information inherent in each incident, a methodology capable of deeply understanding the semantics and context of sentences is imperative. Accordingly, this study utilized the SentenceBERT model to analyze maritime safety tribunal decisions over the last 20 years in the Busan Sea area, which encapsulated data on ship collision incidents. The analysis revealed important keywords potentially responsible for these incidents. Cluster analysis based on the frequency of specific keyword appearances was conducted and visualized. This information can serve as foundational data for the preemptive identification of accident causes and the development of strategies for collision prevention and response.

• Journal of the Society of Disaster Information
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• v.19 no.4
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• pp.859-868
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• 2023

Purpose: In order to enhance safety, the Korea Navy is making efforts to introduce a safety and health management system and to develop a risk assessment system, while safety accidents keeps occurring. A development plan was proposed through an inspection of the Safety Management System(SMS). Method: To diagnose the Korea Navy's safety management system, changes in the safety environment, documentation system, and safety and health management system operation were reviewed, points to be improved were found, and improvement directions were derived. Result: There is a need for an SMS standard that can present the Korea Navy's safety policy and safety management direction, and a safety program that provides guidelines for implementing it in a standardized manner. To this end, we were able to confirm the feasibility of linking the requirements of the US Navy's SMS and the international standard ISO 45001 standard together with the Korea Navy's safety management system. Conclusion: The Korea Navy's safety management system needs to clearly present safety policies and standards, and have public confidence and effectiveness in safety work through a standard program that can implement them, and for this, the development of a Navy SMS is necessary.

• Industry Promotion Research
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• v.8 no.4
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• pp.61-67
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• 2023

This study compared, analyzed, and verified the accident rate and accident fatality rate (per 10,000 workers) of workplaces that perform safety management on behalf of a safety management institutions designated and registered in accordance with the OSHAct and workplaces that perform safety management. According to the research results, the significance was confirmed that the group with a low accident rate was the workplaces that self-appointed safety managers, workplaces with self-appointed safety managers in size with less than 300 employees, and workplaces in the industrial accident insurance industry in the manufacturing and transportation, warehouse, and telecommunications industries. The groups with a low accidental death rate were workplaces with less than 300 employees, workplaces where safety management was performed on behalf of safety management institutions, and workplaces with selfappointment for other medical businesses. In this study, it was confirmed that the accident rate in the safety management agency's workplaces was higher than that of its own appointed workplaces, and that there were some differences in the accident fatality rate depending on the size and industry. Therefore, since the current safety management agency system cannot ensure the effect of preventing accidental deaths, there is a need for comprehensive improvement of the agency system and improvement of the system to strengthen expertise in preventing industrial accidents.

• Journal of the Korean Geosynthetics Society
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• v.23 no.2
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• pp.63-75
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• 2024

Drinking water is an essential element to ensure the basic human right to live, and the quality of clean water must always be ensured. However, domestic water facilities, which were installed intensively in the early 2000s, are deteriorating. The accidents such as discoloration of water such as chromaticity and turbidity as well as leakage of substances frequently occur. However, since it is virtually impossible to replace all water pipes, the detailed standards for maintenance of water pipe network facilities established in 2021 require water pipe cleaning. The swab pig method, one of the water pipe cleaning methods, is a method of physically removing substances in pipes and is evaluated as having the highest cleaning efficiency. However, Swab is highly likely to be damaged or deformed during the cleaning process, and may even be lost. Therefore, in this study, the material of the pig was changed to a material with high compressibility, and it was made as close as possible to the inner wall of the water pipe. And, to maximize cleaning efficiency, a rotation swab pig with a rotation blade was developed. In addition, high-strength wire and winding equipment were additionally developed to eliminate the possibility of loss and to determine the location of the pig. The inlet and outlet are connected with wires, and after verifying the performance of each detailed technology, the technology was applied on a test bed with a 30m section. As a result of the application, the performance of the technology was verified by measuring the process time and evaluating applicability.

• Nuclear Engineering and Technology
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• v.56 no.3
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• pp.803-811
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• 2024

Nuclear accidents such as Fukushima Daiichi have highlighted the potential of passive safety systems to replace or complement active safety systems as part of the overall prevention and/or mitigation strategies. In addition, passive systems are key features of Small Modular Reactors (SMRs), for which they are becoming almost unavoidable and are part of the basic design of many reactors available in today's nuclear market. Nevertheless, their potential to significantly increase the safety of nuclear power plants still needs to be strengthened, in particular the ability of computer codes to determine their performance and reliability in industrial applications and support the safety demonstration. The PASTELS project (September 2020-February 2024), funded by the European Commission "Euratom H2020" programme, is devoted to the study of passive systems relying on natural circulation. The project focuses on two types, namely the SAfety COndenser (SACO) for the evacuation of the core residual power and the Containment Wall Condenser (CWC) for the reduction of heat and pressure in the containment vessel in case of accident. A specific design for each of these systems is being investigated in the project. Firstly, a straight vertical pool type of SACO has been implemented on the Framatome's PKL loop at Erlangen. It represents a tube bundle type heat exchanger that transfers heat from the secondary circuit to the water pool in which it is immersed by condensing the vapour generated in the steam generator. Secondly, the project relies on the CWC installed on the PASI test loop at LUT University in Finland. This facility reproduces the thermal-hydraulic behaviour of a Passive Containment Cooling System (PCCS) mainly composed of a CWC, a heat exchanger in the containment vessel connected to a water tank at atmospheric pressure outside the vessel which represents the ultimate heat sink. Several activities are carried out within the framework of the project. Different tests are conducted on these integral test facilities to produce new and relevant experimental data allowing to better characterize the physical behaviours and the performances of these systems for various thermo-hydraulic conditions. These test programmes are simulated by different codes acting at different scales, mainly system and CFD codes. New "system/CFD" coupling approaches are also considered to evaluate their potential to benefit both from the accuracy of CFD in regions where local 3D effects are dominant and system codes whose computational speed, robustness and general level of physical validation are particularly appreciated in industrial studies. In parallel, the project includes the study of single and two-phase natural circulation loops through a bibliographical study and the simulations of the PERSEO and HERO-2 experimental facilities. After a synthetic presentation of the project and its objectives, this article provides the reader with findings related to the physical analysis of the test results obtained on the PKL and PASI installations as well an overall evaluation of the capability of the different numerical tools to simulate passive systems.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.407-417
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• 2024

The objective of this study is to predict and reduce potential damage caused by chlorine gas leaks, a hazardous material, when vehicles transporting it overturn due to accidents or other incidents. The goal is to forecast the anticipated damages caused by chlorine toxicity levels (ppm) and to design effective response strategies for mitigating them. To predict potential damages, we conducted quantitative assessments using the ALOHA program to calculate the toxic effects (ppm) and damage distances resulting from chlorine leaks, taking into account potential negligence of drivers during transportation. The extent of damage from toxic gas leaks is influenced by various factors, including the amount of the leaked hazardous material and the meteorological conditions at the time of the leak. Therefore, a comprehensive analysis of damage distances was conducted by examining various scenarios that involved variations in the amount of leakage and weather conditions. Under intermediate conditions (leakage quantity: 5 tons, wind speed: 3 m/s, atmospheric stability: D), the estimated distance for exceeding the AEGL-2 level of 2 ppm was calculated to be 9 km. This concentration poses a high risk of respiratory disturbance and potential human casualties, comparable to the toxicity of hydrogen chloride. In particular, leaks in urban areas can lead to significant loss of life. In the event of a leakage incident, we proposed a plan to minimize damage by implementing appropriate response strategies based on the location and amount of the leak when an accident occurs.

• Journal of the Society of Disaster Information
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• v.20 no.1
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• pp.47-59
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• 2024

Purpose: This study aims to propose measures for the prevention of fire and explosion accidents within manufacturing facilities by improving the existing classification criteria for hazardous locations based on the leakage patterns of flammable liquids. The objective is to suggest ways to safely manage ignition sources and combustible materials. Method: The hazardous locations were calculated using "KS C IEC 60079-10-1," and the calculated explosion hazard distances were visualized in 3D. Additionally, the formula for the atmospheric dispersion of flammable vapors, as outlined in "P-91-2023," was utilized to calculate the dispersion rates within the hazardous locations represented in 3D. Result: Visualization of hazardous locations in 3D enabled the identification of blind spots in the floor plan, facilitating immediate recognition of ignition sources within these areas. Furthermore, when calculating the time taken for the Lower Explosive Limit (LEL) to reach within the volumetric space of the hazardous locations represented in 3D, it was found that the risk level did not correspond identically with the explosion hazard distances. Conclusion: Considering the atmospheric dispersion of flammable liquids, it was concluded that safety management should be conducted. Therefore, a method for calculating the concentration values requiring detection and alert based on realistically achievable ventilation rates within the facility is proposed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.4
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• pp.324-331
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• 2024

The height of large car and truck carriers from the keel to the wheel house is 44 ~ 46 m, and as the car-carriers increases in size, it exhibits the 'top heavy' characteristic, where the upper section is heavier than the lower section. This study aims to estimate the maximum outward heel angle of the Golden Ray car-carrier (G-ship) during turning maneuvers for accident investigation and the prevention of similar accidents. The theoretically calculated maximum outward heel is 7.5° (at 19 kn, rudder angle 35°) with a GM of +3.0 m or higher, and 16.7° with a GM of +1.85 m. Meanwhile the experimentally modified maximum outward heel is 10.5° (at 19 kn, rudder angle 35°) with a GM of +3.0 m or higher, and 23.3° with a GM of +1.85 m. The G-ship is maneuvered during an accident at a speed of 13 kn, at starboard rudder angle of 10° to 20°, it changes course from 038°(T) to 105°(T) based on the instructions of the on-board pilot. At this time, the maximum outward heel is estimated to be between 7.8° and 10.9° at the port side, which is 2.2 times higher than the normal outward heel. In the IS code, cargo ships are required to exhibit a minimum GoM of +0.15 m or more. The maneuvered G-ship exhibits a GoM of +1.72 m. It is not maneuvered because it fails to satisfy the international GoM criteria and because its GoM is insufficient to counteract the heeling moment during the maneuver. This study is performed based on accident-investigation results from the Korea Maritime Safety Tribunal and the USCG.

• Journal of Practical Engineering Education
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• v.16 no.4
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• pp.529-540
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• 2024

In industrial sites, experiential virtual training contents are partially used to replace high-risk and high-cost training, and virtual training contents development is also becoming active along with the increasing demand for non-face-to-face industries. Existing studies mainly focused on quantitative research through surveys, and only measured the change in users' learning commitment. This study attempted to investigate the effect of the combination of theoretical education and virtual training on the improvement of actual job performance in a dual vocational training environment by conducting an experimental study. This study studied whether the combination of theoretical education and virtual training can improve the performance of vocational training in dual vocational training (comparative work and learning) in which companies and schools participate. The results of pre- and post-evaluation of vocational training using traditional vocational training and virtual training contents were compared with 24 vocational training trainees. As a result of the study, it was demonstrated that the outcome of virtual training education was higher than that of traditional vocational training, and the combination of virtual reality-based education was more effective in theoretical education. This study suggests that the virtual training content presents a new paradigm for industrial safety education, and through the interview results of trainees, it was confirmed that virtual training can lead to a change in attitude toward safety beyond just knowledge transfer. This contributes to the prevention of safety accidents in industrial sites and provides important implications for improving the quality of vocational training.

• Smart Media Journal
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• v.13 no.8
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• pp.79-86
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• 2024

In design studies, there has been extensive prior research on accident and disaster prevention, but it mainly focuses on visualization methods to improve visibility. Most accidents and disasters are caused by human factors. However, there is little design research that considers human characteristics that manifest in dangerous situations. This study aims to identify the concepts and characteristics of safety information design that reflects human traits. It examines the concepts of risk and safety from a social science perspective and looks into human visual information processing from a cognitive neuroscience perspective. Additionally, it explores the relationship between human information processing and accident rates in dangerous situations from a psychological perspective. Based on these analyses, the study distinguishes between conventional information design and safety information design, ultimately identifying the features of safety information design that incorporates human traits. The key findings are as follows: First, information should be presented considering the human tendency to suspend rational judgment in dangerous situations. Second, appropriately dispersing or concentrating attention according to the level of risk can serve as an opportunity to minimize harm. Third, it was found that sensory and perceptual characteristics should be given top priority in the field of risk and safety information design. Through these findings, the study concludes that a design approach that reflects human traits in safety information design can ultimately be a key indicator for improving safety levels.