• Journal of the Korean association of regional geographers
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• v.17 no.3
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• pp.332-347
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• 2011

This study is to analyze on territorial education described in geography textbooks in Korea and Japan. The following is the result that shows similarities and differences of the geography textbooks when it comes to territorial education. Korea and Japan have a contrasting territorial background. However, both countries start their territorial education by learning the location and shape of their country. Japanese geography textbooks focus on what people in the world think of Japan, but in case of Korea, the geography textbooks focus on how Koreans look at the world. In short, the territorial education in Japan try to emphasize Japan from the view point of the world. The next common ground is that the two countries provide territorial models in their geography textbooks in order to increase understanding. However, the Japanese students are provided with these territory models much earlier than Korean students and these models help them visualize and solidify their concept of territory. And, the two countries both put great importance on teaching territorial sea. In Japan, they try to include EEZ(Exclusive Economic Zone) in their territory. Considering these facts, it can be concluded that Japan is enlarging their concept of national territory as maritime territory. Lastly, after learning of territory the two countries both treat on territorial problems. But Korea treats passively territorial problem as such Dokdo, but Japan treats actively their territorial problems. Like that, the contents of territorial education described in geography textbooks in Korea and Japan are similar in terms of selection, but differ in quality in terms of organization. Therefore, future territorial education in Korea will be actively and successively done through succession and sequence of geography curriculum.

• Journal of Navigation and Port Research
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• v.37 no.1
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• pp.29-34
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• 2013

In this study, the corelation among the knowledge of and attitude to health care and the actual health protective practices of seafarers was surveyed and analyzed in order to provide the management method for improving seafarers' health care. The subjects of this study were 516 seafarers who took refresh training courses in Korea Institute of Maritime and Fisheries Technology. The questionnaire was constructed under the Guidelines for National Health of the Ministry of Health and Welfare and modified for studying seafarers' health state. The collected data were analyzed by SPSS package. The results were as follows: 1) The older, married, religion believer, higher ranker, the man who have longer career have the higher degree of knowledge, attitude, and practice-degree(p<0.05). 2) The degree of knowledge, attitude, and practice are $4.24{\pm}0.35$, $3.45{\pm}0.41$, and $3.39{\pm}0.22$ in mean by 5-score scale, respectably. 3) The corelation among the degree of knowledge, attitude, and practice was significant(r=0.33~0.63, p<0.05).

• Journal of the Korea Convergence Society
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• v.5 no.4
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• pp.113-119
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• 2014

Fire fighters should eat their meal very fast in order to arrive in the emergency scene on time. The purpose of the study is to investigate the influence of eating speed on the health of the fire fighters. The subjects were fire fighters, National maritime police, soldiers, public officials, university students, and company employees. The fire fighters had the shortest eating time of 8 minutes 29 seconds, and eating speed of National maritime police was 8 minutes 33.17 seconds, and public officials had 12 minutes 49.33 seconds. Soldiers had 10 minutes 15 seconds, university students had 14 minutes 15 seconds, and company employees had 16 minutes 51 seconds in eating their meals. The previous studies said that eating speed had influenced on the metabolic syndrome and the survey on the American fire fighters showed that the fire fighters gained 7.7 pounds during the past 8 years. Through this study, it is necessary to implement the right eating habit that is able to slow down the eating speed in the Korean fire fighters. The Fire Academy should provide the right eating habit education program to the fire fighters.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.689-696
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• 2018

System grounding is applied to the neutral point of a power source to secure the from any abnormal voltage and/or grounding fault. System grounding, which is applied mainly in ships is an ungrounded and resistance grounded system. Vessels using the MV power system with 3.3kV, 6.6kV, and 11kV mainly adopt a high resistance grounding system among the resistance grounding systems. The ground fault accounts for 95% of all faults occurring in the electrical system and when a fault occurs, the line-to-ground voltage of the power system is increased excessively, which adversely affects the onboard insulation system. This study analyzed the variation characteristics of the line-to-ground voltage neutral point according to the degree of ground fault in a resistance ground system applied in vessels. For this purpose, the characteristics of the grounding system were first explained, and the modeling of the neutral point potential of the line-to-ground voltage of the resistance grounding system in the vessels was derived. Finally, this study examined how the line-to-ground voltage, line voltage, and neutral point change according to various variable environments through MATLAB simulations.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.2
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• pp.121-128
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• 2020

The Marine Safety Culture Index (MSCI) was developed in the year 2018 for objectively assessing the public safety culture levels and for incorporating it as data to spread knowledge regarding the marine safety culture. The method for calculating the safety culture index should include issues that may affect the safety culture and should consist of appropriate attributes for estimating the current status. In addition, continuous verification and supplementation are required for addressing social and economic changes. In this study, to determine whether the questionnaire designed by marine experts reflects the people's interests and needs, we analyzed 915 marine safety proposals. Text mining was employed for analyzing the unstructured data of the marine safety proposals, and network analysis and topic modeling were subsequently performed. Analysis of the marine safety proposals was centered on attributes such as education, public relations, safety rules, awareness, skilled workers, and systems. Eighteen questions were modified and supplemented for reflecting the marine safety proposals, and reliability of the revised questions was analyzed. Furthermore, compared to the previous year, the questionnaire's internal consistency was improved upon and was rated at a high value of 0.895. It is expected that by employing the derived marine safety culture index and incorporating the improved questionnaire that reflects the requirements of marine experts and the people, the improved questionnaire will contribute to the establishment of policies for spreading knowledge regarding the marine safety culture.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.802-808
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• 2019

DC motors are used extensively on shipboard, including as the ship's winch operating motor, owing to their simple speed control and excellent output torque characteristics. Moreover, they were used as propulsion motors in the early days of electric propulsion ships. However, mechanical rectifiers, such as brushes, used in DC motors have certain disadvantages. Hence, brushless DC (BLDC) motors are increasingly being used instead. While the electrical characteristics of both types of motors are similar, BLDC motors employ electronic rectifying devices, which use semiconductor elements, instead of mechanical rectifying devices. The inverter system for driving conventional BLDC motors uses a two-phase excitation method so that the waveform of the back electromotive force becomes trapezoidal. This causes harmonics and torque ripple in the phase current switching period in which the winding wire through which the current flows is changed. Researchers have studied and presented various methods to reduce the harmonics and torque ripple. This study applies a cascaded H-bridge multilevel inverter, which implements a proportional-integral speed current controller algorithm in the driving circuit of the BLDC motor for electric propulsion ships using a power analysis program. The simulation results of the modeled BLDC motor show that the driving method of the proposed BLDC motor improves the voltage waveform of the input side of the motor and remarkably reduces the harmonics and torque ripple compared with the conventional driving method.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.7
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• pp.773-778
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• 2015

Global warming has recently become an issue that has resulted in a growing trend to minimize environmental pollution. The International Maritime Organization (IMO) has shown that the majority of marine atmospheric pollution occurs as a result of emissions from marine vessels. Therefore, the environmental regulations and emission standards regarding marine vessels have gradually become stricter, and the research and development in this area is experiencing significant progress. In this study, a nozzle for a fuel oil scrubber was investigated using computational fluid dynamics (CFD) and particle imaging velocimetry (PIV). Experiments were conducted on scaled-down model of the scrubber to determine its performance, which was then compared with CFD results. Based on the experimental results, it was found that at a spray angle of $66^{\circ}$, the spray velocity at the nozzle was 20.1 m/s. From this comparison, a full-scale scrubber model was analyzed using CFD, and the effect of the positioning of the nozzle was studied.

• Journal of Navigation and Port Research
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• v.29 no.1 s.97
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• pp.35-42
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• 2005

This study aims at analyzing the extent of seafarers' perception on their stress and ways to cope with the stress and providing fundamental data for establishing on the stress management of seafarers. In this paper 428 seafarers, who were in the fire-fighting and survival technique training course in Korea Institute of Maritime and fisheries Technology, were sampled and asked to fill out two kinds of questionnaire. One is a questionnaire on seafarers' stress perception and the other is that on the measure of their coping with stress. The collected data were analyzed by using descriptive statistics, t-test and ANOVA by SPSS 10.1 package. The results of this study are as follow. 1) There were significant differences of stress perception in navigation area, marital status, amount of smoking, frequency of drinking, exercise, sleep pattern, sleeping hours, leisure time, and job satisfaction 2) There were significant differences of method coping with stress in current position, navigation area, age, ship career, level of education, marital status, yearly income, frequency of drinking, amount of drinking, exercise, sleep pattern, and job satisfaction 3) The relation between stress perception and ways of coping with stress showed that the group with higher stress perception tended to use emotion-focused coping style and desirable thinking.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.3
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• pp.209-219
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• 2016

The survey was conducted to investigate biomass and distribution of fisheries resources using a quantitative echo sounder and a fixed gillnet around Marado coast of Jeju to obtain the scientific basic data for dispute resolution with a large purse seine fishery and coastal fishing and policy establishment of reasonable fisheries resources. Hydroacoustic surveys were conducted six times (November 28~29, 2015 (night), February 23~24, 2016 (night) and March 3~4, 2016 (night/day), March 30~31, 2016 (night/day)) using a quantitative echo sounder. The pelagic fish densities were relatively higher around Marado in November 2015, February 2016 and March 3~4, 2016. However, demersal fish densities were relatively higher in Jeju coastal waters on March 30~31, 2016. Catch data using fixed gill net were used to calculate biomass. Based on the hydroacoustic data, fish length-weight function and target strength information of dominant fish, the biomass of fishes were estimated as follow: 5.64 ton CV = 70.2% at night on November 28-29 2015, 7.14 ton CV = 35.8% of pelagic fish and 530.77 ton CV = 34.6% of demersal fishes at night on February 23-24 2016, 2.34 ton CV = 56.7% of pelagic fish and 571.93 ton CV = 40.3% of demersal fish at daytime, 1.39 ton CV = 48.4% of pelagic fish and 194.59 ton CV = 54.3% of demersal fish at night on March 3~4 2016, 0.37 ton CV = 72.9% of pelagic fish and 338.79 ton CV = 99.7% of demersal fish at daytime, 0.24 ton CV = 21.3% of pelagic fish and 68.61 ton CV = 53.8% of demersal fish at night on March 30~31 2016.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.6
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• pp.689-695
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• 2015

The offshore plant crews that were commissioned in the commercial startup phase boarded the offshore plant in two shifts until the end of the project. The crews who were hired by the owner side stayed in the original offshore plant during the project. However, most of the offshore plant commissioned members who were dispatched from the shipyard were accommodated in the offshore accommodation barge. For this reason, they were exposed to many accidents since there are a lot of people staying in a small space. This study suggested a method for improving survival rate at offshore accommodation barge in terms of life safety. It is assumed that the fire accident among unfortunate events which take place in the offshore accommodation barge mainly occurred. So, this study analyzed the safety evacuation for offshore plant employees using fire simulation model based on both domestic and international law criteria. In particular, When fire occurs in the offshore accommodation barge, the periodically well trained crews are followed safety evacuation procedure. whereas many employees who have different background such as various occupations, cultural differences, races and nationality can be commissioned with improper evacuation behaviors. As a result, the risk will be greater than normal situation due to these inappropriate behaviors. Therefore, This study analyzed the Required Safe Escape Time (RSET) and Available Safe Escape Time (ASET). Also it was suggested the improvement of structure design and additional arrangement of safety equipment to improve the survival rate of the residents in offshore accommodation barge.