• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.772-779
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• 2019

This study identified the relationship between leisure attitudes, leisure promotion, leisure drugs, leisure satisfaction, and the intention to rejoin maritime sports by the participants of this study. The researchers selected 542 adult men and women who live in Seoul and the Incheon, Gyeonggi and Chungcheong provinces, and who were currently engaged in marine sports activities. Data processing was performed using SPSS 21.0 and AMOS 18.0 for the frequency analysis, reliability analysis, confirmatory factor analysis, correlation analysis and structural equation model analysis. The results of this study were as follows. First, the leisure attitudes of marine sports participants did not affect the promotion of leisure (p>.05). Second, the attitude towards leisure of the marine sports participants had a negative effect on using leisure pharmaceuticals (p<.05). Third, the leisure attitudes of marine sports participants affected their leisure satisfaction (p<.05). Fourth, the promotion of leisure activities of the marine sports participants did not affect their leisure satisfaction (p>.05). Fifth, the leisure restrictions of marine sports participants did not affect their leisure satisfaction (p>.05). Sixth, the leisure activities of marine sports participants affected the intention of rejoining (p<.05).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.273-282
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• 2016

This study analyzed the origin and status of the registration system of water leisure craft to suggest an improvement plan for the ocean leisure industry. To identify the transition of the registration system, related water leisure craft, registration procedures and revised acts from "water leisure safety act", which was established in the early 2000 and enacted since then were examined. To understand the problems raised, the management of the registration system and related other systems were analyzed. The results were as follows. First, the registration system was designed just to check the number of registrations of water leisure craft so it does not provide various and useful information that administrators and registrants want. Second, it is impossible to utilize and reconstruct the information regarding water leisure craft. In addition, the current registration system does not have a data sharing system with the Ministry of Government Administration and Home Affairs so self-governing administrations are not connected to each other or to other electronic government systems. To resolve these problems, the construction of a new registration system is required. The new registration system of water leisure craft should facilitate not only processing registration files and administration work, but also multiple electronic governmental services that provide the water leisure users with useful information and encourage them to learn about their craft management and so on.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.270-276
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• 2019

According to the International Maritime Organization (IMO) 2020 Regulation, ships operating outside designated emission control areas (ECA) have to use low-sulfur oil with a sulfur content of 0.5% or less by January 2020. To minimize the consumption of high-priced low-sulfur oil, it is urgent to introduce efficient energy-saving devices (ESD), and contra-rotating propeller (CRP) systems are well known to be the most effective one. The shafting system that drives a CRP is composed of an inner shaft and an outer one and has a mutually influential system that is much more complex and heavier than a general shafting system. An initial design was carried out to install a CRP system for the first time in Korea. The purpose of this study is to verify whether the journal bearing meets the classification's design criteria through a bearing reaction force analysis for the classification's approval of the initial design. It is ideal for the thrust of the propeller to act on the center of the shaft, but thrust eccentricity occurs due to the uneven wake caused by the stern shape. Load conditions were applied while considering thrust eccentricity to perform the shaft analysis, and the results were compared with the classification's criteria.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.281-286
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• 2021

The International Maritime Organization recently proposed a policy to establish a preemptive response strategy for exhaust gas pollution on board ships according to the recent strengthening of the sulfur content regulations. Discussions on improving the fuel oil quality and reducing emissions are also ongoing. Fuel oil quality information, which is one of the main concerns internationally, is increasing as the sulfur content standard is being applied from the current 3.5% to 0.5% by 2020. From the perspective of shipping companies and recipients, the essential quality of fuel oil is also requested for domestic and international fuel oil information, basic properties, correlation information between characteristics for application of solid ships and ships. The current standard for the basic quality of fuel oil is generally used, but the nature and composition of the fuel oil are very complex, and the interpretation of the basic quality is complicated because there are many cases outside the scope of the basic standard. Various factors were analyzed for the basic quality of fuel oil in terms of the basic quality of fuel oil, optimization of operation in ships, and fuel efficiency in ships. Moreover, the possibility of applying the standard according to the dilution was suggested.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.579-585
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• 2019

Increasing the detection probability of underwater targets necessitates securing the towing stability of the active towed SONAR. In this paper, to confirm the effects of tail wing fin on towing attitude and towing stability, two scale model experiments and one sea trials were conducted and the results were analyzed. The scale model tests measured the towing behavior of each of the tail fin shapes according to towing speed in a towing tank. The shape of the tail fin used in the scale model test was tested with an I-type tail fine and four Y-type tail fins, totaling five tail fins of the two kinds. The first scale model test confirmed that the Y-type tail fin was superior to the I-type tail fin in towing attitude and towing stability. The second scale model test confirmed the characteristics of the vertical tail fin height increase and the lower horizontal tail fin inclination angle application shape based on the Y-type tail fin. The shape of the application of the lower horizontal tail fin inclination angle showed the best performance. In order to verify the results of the scale model test, a full size model was constructed, sea trials were performed, and the towing attitude was measured. The results were similar to those of the scale model test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.362-370
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• 2019

This study was conducted to investigate effects of 12 weeks of combined exercise training with blood flow restriction (BFR) on body composition (weight, %body fat, lean body mass, body mass index (BMI)) and cardiovascular responses (brachial-ankle pulse wave velocity (ba PWV) and ankle-brachial index (ABI)) in elderly women. Participants (N = 43, Females) were randomly assigned into a combined exercise with BFR (n = 14, BFR), only combined exercise (n =14, EX) or non-exercise control group (n = 15, CON). Two-way repeated measures ANOVA with contrast testing was utilized for data analysis. Alpha was set at p < 0.05. Body composition (weight, %body fat, BMI) in BFR was significantly changed, and %body fat in EX was significantly decreased, but there was no change in the CON. In addition, the right and left ba PWV values in the BFR were significantly decreased, while only the left side ba PWV in EX was significantly decreased and there was no change in the CON. Moreover, the % change and effect size of most variables in the BFR were higher than the EX. Taken together, the results indicate that even though BFR and EX groups performed the same combined exercise training, BFR had additional stimulations of the sympathetic nerve system due to blood flow restriction. Thus, BFR training is more beneficial and has greater effects on body composition and cardiovascular responses in elderly females.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.350-361
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• 2019

The fourth industrial revolution based on the intelligent revolution has revolutionized the society as a whole, and it has also affected the defense sector. Various aspects of the war have been changing with the development of technology. In particular, various strategies such as research and development of core technology related to defense unmanned system field and infrastructure are being established based on the fourth industrial revolution technology. In this paper, we have conducted a study to select the technology required for maritime unmanned systems, which can be considered as a priority consideration for the future development of the core technology to be secured prior to the development of the weapon system. First, the core technology prioritization model for the marine unmanned system was established, and the technology fields of the unmanned robot were reclassified and integrated in the related literature such as the classification of the defense technology standard. For the empirical analysis, a questionnaire survey was conducted for 12 specialists who are engaged in the planning of weapons systems, and the importance of technical fields that require development in the development of marine unmanned systems was analyzed. As a result, it was possible to identify the key technology areas that should be considered in selecting the key technologies proposed by the military groups, research institutes, and companies. This could contribute to the establishment of the technology roadmap to develop the marine unmanned system from the future point of view.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.251-257
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• 2021

An underwater platform operating a passive sonar needs to acquire the target position to perform its mission. In an environment where sea-floor reflections exist, the position of a target can be estimated using the difference in the arrival time between the signals received through multipaths. In this paper, a method of localization for passive sonar is introduced, based on the EKF (Extended Kalman Filter) using the multipath time difference of arrival in underwater environments. TMA (Target Motion Analysis) requires accumulated measurements for long periods and has limitations on own-ship movement, allowing it to be used only in certain situations. The proposed method uses an EKF, which takes measurements of the time differences of the signal arrival in multipath environments. The method allows for target localization without restrictions on own-ship movement or the need for an observation time. To analyze the performance of the proposed method, simulation according to the distance and depth of the target was performed repeatedly, and the localization error according to the distance and water depth were analyzed. In addition, the correlation with the estimated position error was assessed by analyzing the arrival time difference according to the water depth.

• Knowledge Management Research
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• v.21 no.4
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• pp.59-88
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• 2020

This study is to examine the influence of Asian countries on the economic field, and to explain the characteristics and purposes of China's Belt and Road Initiative using data analysis. The purpose of this study is to identify and analyze the influence and characteristics of China's One-to-One Road Initiative on the economic sector by examining trade and investment in Asian countries adjacent to China. In particular, the One-to-One Road initiative is proceeding in a way that connects China and neighboring countries. It is to understand the dependence of the Asian countries in China on the Chinese economy. In addition, it is intended to derive implications by grasping and evaluating what the level is based on data. This study also attempts to grasp the influence and ripple effects of the one-on-one strategy on the Chinese economy and the North Korean economy, where dependence is deepening. Recently, the strategy for Asian countries through a one-to-one initiative in China has been restructured in the framework of the construction of the "21st century Maritime Silk Road" and emphasizes the cooperation mechanism led by the country. In progress of the one Belt and One Road, Chinese ICT companies are remarkable. This study looked at the influence of China's digital one Belt and One Road on Asian countries.

• Journal of Fisheries and Marine Sciences Education
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• v.4 no.2
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• pp.121-128
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• 1992

Taking the present circumstances into account that we are approaching the realization stage of interchange and cooperation between North and South Korea through a preparatory stage, recovery of national homogeneity is an essential precondition for reunification. The important first Step is pursuing of recovery of educational homogeneity for this purpose. The authors carried out 8 general observation on the fundamental educational system with ideology, on the actual state and characteristic of educational system for industrial technicians, and especially on the educational system for fisheries technical manpower in the North Korea. It was found that the North Korea's basic idea of educational policy is constituted by bringing up the communistic human beings on the ground of "the Ideas of Identity" and by bringing up industrial technical manpower for development of communistic economic. The basic educational system consists of 1-4-6-4 school years system, and 11 years of compulsory education up to the higher middle schools is imposed to all people. The educational system for industrial technicians is also composed of the regular school system which is following the basic educational system and of the irregular school system which is being attached to the industrial bodies. The fisheries educational system is very similar to the general educational system for industrial technicians, and the fisheries workers are treated more warmly in comparison with the workers engaging in the other industrial fields. By this study, the authors failed to find out the concrete content of the fisheries educational system including the curriculum owing to the lack of information, but this task should be studied continuously to make provision of reunification in the near future. Expressly, a continuous and profound research is required to be carried out on actual accepted state of the international maritime conventions together with the marine officers' certification system for the shipping and fisheries fields in the North Korea.