• Journal of Navigation and Port Research
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• v.39 no.4
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• pp.277-283
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• 2015

MS(Mild Steel), HTS(High Tensile Steel), HYS(High Yield Steel), AL(Aluminum Alloy) and Composite Materials are used for vessels. Steel Materials are mostly used for vessels because body of a ship have to perform the basic functions such as watertight, preserving the strength and supporting the equipments. The vessels primarily carry out a mission at ocean, so that body of a ship is necessarily rusted. There are several methods to protect the corrosion of vessels such as painting, SACP(sacrificial anode cathodic protection) and ICCP(impressed current cathodic protection). For the sacrificial anode cathodic protection, Al and Zn alloys are normally used. Heavy metals are added to the Al and Zn Alloys for improving the corrosion properties but they are so harmful to the human and environment. Therefore, the use of these heavy metals is strictly regulated in the world. In this paper, Al and Zn Alloys are made by adding the trace elements(Ma, Ca, Ce and Sn) which is not harmful to the human and environment. SEM, XRD, Potentiodynamic Polarization test and Current Efficiency test are conducted for evaluation of Al and Zn Alloys. As a result of the experiment, Al-3Zn-0.6Sn and Zn-3Sn Alloys are more efficient than other Alloys.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.759-767
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• 2021

Most weapons systems that are Force Integration are expensive equipment that reflects the latest technology, and the operation and maintenance cost is increasing continuously. Factors that efficiently operate and maintain these weapon systems include maintenance plans, economic costs, and repair part requirements. Among them, predicting the repair parts requirements during the life cycle in advance is an important way to increase operation and maintenance cost efficiency and operating availability. The start of requirement analysis for repair parts is a calculation of the CSP (CSP: Concurrent Spare parts, CSP hereafter) that is distributed when the weapon system is deployed. The CSP is an essential component of achieving the operating availability during this period because the weapon system aims to successfully perform a given operation mission without resupply for an initial set period. In the present study, the CSP calculation method was analyzed, reflecting the failure rate and operating time of items, but the analyzed CSP was aimed at preparing for technical failure, but in the initial operating environment, it is limited in coping with unexpected failures caused by human error. The failure is not included in the scope of free maintenance and is a serious factor in making the weapon system inoperable during the initial operation period. To prevent the inoperable status of a weapon system, CSP that considers human error is required in the initial operating environment, and the calculation criteria and measures are proposed.

• Convergence Security Journal
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• v.20 no.4
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• pp.143-151
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• 2020

The cyber battlefield called the fifth battlefield, is not based on geological information unlike the existing traditional battlefiels in the land, sea, air and space, and has a characteristics that all information has tightly coupled correlation to be anlayized. Because the cyber battlefield has created by the network connection of computers located on the physical battlefield, it is not completely seperated from the geolocational information but it has dependency on network topology and software's vulnerabilities. Therefore, the analysis for cyber battlefield should be provided in a form that can recognize information from multiple domains at a glance, rather than a single geographical or logical aspect. In this paper, we describe a study on the development of the cyber operation COP(Common Operational Picture), which is essential for command and control in the cyber warfare. In particular, we propose an architecure for cyber operation COP to intuitively display information based on visualization techniques applying the multi-layering concept from multiple domains that need to be correlated such as cyber assets, threats, and missions. With this proposed cyber operation COP with multi-layered visualization that helps to describe correlated information among cyber factors, we expect the commanders actually perfcrm cyber command and control in the very complex and unclear cyber battlefield.

• Journal of Space Technology and Applications
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• v.3 no.1
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• pp.26-43
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• 2023

As Korean first lunar probe, Danuri, succeeded in entering lunar orbit, Korean new space exploration plans such as Mars exploration can be expected. Korean space exploration payload is developed only in a limited field, so there is a need to create a new space exploration payload. In foreign countries, there is a mass spectrometer as a basic equipment for space exploration, and it is a very useful payload that encompasses the exploration of life through the analysis of organic matter as well as the observation of the atmosphere and volatile substances of the exploration target. However, Korea has never developed a mass spectrometer payload for space exploration, so it is necessary to secure technology in preparation for future space exploration. Before that, we look at the scientific achievements of foreign mass spectrometer payloads for space exploration and identify trends.

• Knowledge Management Research
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• v.24 no.4
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• pp.23-42
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• 2023

This study originated from recognition of importance of firefighters' decision-making in fire response, coupled with existing gap in research. By utilizing Q-methodology, the study aimed to categorize firefighters' subjectivity in fire response decision-making. Through this categorization, the study sought to highlight insights into the current technological and data limitations, as well as potential directions for future R&D in the field of firefighting. The findings of the study revealed that firefighters' subjectivity could be classified into three factors: "emphasis on direct information related to rescue," "emphasis on information related to the target property," and "emphasis on information related to command and coordination." The study theoretically confirmed that the subjectivity of firefighters' decision-making in fire response is partially influenced by their experiences and job. Additionally, the study's significance lay in its approach of collecting specific decision-making factors in fire response, moving beyond general theoretical models. Furthermore, from a policy perspective, the typification of decision-making factors contributed to connecting the identified data-based administrative needs from prior studies. Insights from the study emphasized the importance of leveraging on-site experience in Korea to aid decision-making, calling for the development of equipment and data collection methods that can rapidly and accurately assess on-site conditions.

• Geophysics and Geophysical Exploration
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• v.14 no.1
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• pp.80-87
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• 2011

Autonomous underwater vehicles (AUVs) present the important advantage of being able to approach the seafloor more closely than surface vessel surveys can. To collect bathymetric data, bottom material information, and sub-surface images, multibeam echosounder, sidescan sonar (SSS) and subbottom profiler (SBP) equipment mounted on an AUV are powerful tools. The 3000m class AUV URASHIMA was developed by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC). After finishing the engineering development and examination phase of a fuel-cell system used for the vehicle's power supply system, a renovated lithium-ion battery power system was installed in URASHIMA. The AUV was redeployed from its prior engineering tasks to scientific use. Various scientific instruments were loaded on the vehicle, and experimental dives for science-oriented missions conducted from 2006. During the experimental cruise of 2007, high-resolution acoustic images were obtained by SSS and SBP on the URASHIMA around the northern Kumano Basin off Japan's Kii Peninsula. The map of backscatter intensity data revealed many debris objects, and SBP images revealed the subsurface structure around the north-eastern end of our study area. These features suggest a structure related to the formation of the latest submarine fan. However, a strong reflection layer exists below ~20 ms below the seafloor in the south-western area, which we interpret as a denudation feature, now covered with younger surface sediments. We continue to improve the vehicle's performance, and expect that many fruitful results will be obtained using URASHIMA.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.410-416
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• 2016

After the Sewol Ferry accident, the importance of maritime safety has been emphasized in Korea. In particular, educational and experience training are not only being conducted for maritime personnel but also in schools and at maritime-related organizations in order to broadly instill maritime safety awareness. Based on SOLAS regulations, safety education for sailors conducted every 10 days passenger boats, and fire-fighting drills and abandon-ship training should be conducted once a month on merchant ships. After the Sewol Ferry accident, the maximum number of trainees was reduced from 40 to 20 in order to improve the effectiveness of these training sessions by requiring all trainees to participate in the actual training. The current training process consists of two steps: textbook-based theoretical training and actual practice. Current training environment provides limited capability from human and facility recourses which limit the numbers of trainee participated and system operation time. By introducing the simulation training, it will improve the trainee skill and performance prior to the on-site training and allow the more effective and rapid progress on actual practice. Therefore, it will be proposed the three-step training method in order to improve the effectiveness on fire-fighting drill in Maritime Safety Education on this study. This study suggests a three step training method that would increase the efficiency of maritime safety education. An image-training step to enhance individual task awareness and equipment usage via simulation techniques after theoretical training has been added. To implement this simulation, a virtual training session will be conducted before actual training, based on knowledge obtained from theoretical training, which is expected to increase the speed with which trainees can adapt during the practical training session. In addition, due to the characteristics of the simulation, repeated training is possible for reaction drills in emergency circumstances and other various scenarios that are difficult to replicate in actual training. The efficiency of training is expected to improve because trainees will have practiced before practical training takes place, which will decrease the time needed for practical training and increase the number of training sessions that can be executed, increasing the efficiency of training overall. This study considers development methods for fire-fighting drill simulations using virtual reality techniques.

• Korean Security Journal
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• no.18
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• pp.119-141
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• 2009

Administrative execution by proxy is one of forced executions of administration and is also called as "enforced execution by proxy" in which administration institutions or the third party executes by proxy on behalf of parties who did not execute obligations under administration law and files claims to compensate expenses required in the proxy execution. Despite the actual site of administrative execution by law, social problems are generated because various violence and behaviors of infringement of human rights between executer and obligator are rampant and thus causing human damages since forced execution by physical force is carried out and cases of police indictments and petition to human rights committee are gradually increasing. Majority of people mobilized in this actual site of violence are supplied by private security companies which provide service contract and mobilization of people without qualification of guards or security service and irrational execution by proxy and violent actions by so-called service hooligans connected to violence organizations are now becoming social issues. In these actual sites of violence, structurally very complicated problems such as economic rights, right of residence, struggle for living, and intervention by outsiders are contained. This thesis has analyzed causes of outbreaks of violence and discussed about improvement countermeasure by paying attention to mobilization of people by private security companies. As the result, through revision and improvement of laws and systems, execution institution and policemen must be present at actual sites of execution by proxy to control physical execution of private security companies to be carried out legally and when violent collisions are occurring, it shall be stipulated that police should immediately intervene. Practices of execution by proxy of execution administration institutions shall be avoided and causes of occurrences of violence shall be eliminated by discrete decisions of execution by proxy, elimination of service contract conditions focused on accomplishments, and stipulation of responsibility of execution institutions when problems occur. Practices of solving petitions through collective actions of obligators shall be eliminated and strict enforcement of laws such as disturbance of official execution or compensation claims for expenses of execution by proxy must be carried out and intervention by the third parties must be intercepted. Mobilization of manpower by security companies shall be limited to people with prior registration who have acquired and finished qualification and education by security business law and before putting them on actual sites, it shall be obliged that execution plan with clear written records of working location, mission, and work rules must be submitted in advance to police station in charge and also they must be controlled to follow laws and statutes such as uniform and equipments. In addition, personal criminal responsibility for violent actions must be clearly stipulated and advanced securing soundness of security companies such as limits of service contracts with records of accidents is required. Order placement behaviors of special organizations under the pretext of rehabilitation business must be eradicated and companies with capability and strong intention of observation of laws must be able to receive orders by intercepting chains of contracts and sub-contracts. Issues of improvement countermeasure of social problem, living, and compensation including rights of residence and environment are excluded from the discussion.