• 수산해양교육연구
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• 제19권1호
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• pp.8-18
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• 2007

In order to define their relative influence, this study analyzed causal relationships between school adjustment of middle school students and such related variables as locus of control and stress, including clarification of other significant variables affecting school adjustment. Participants were a sample of 331 students from 3 middle schools in Busan. Correlation, analysis of covariance structure modeling, and model-fitness tests were applied to the data. Results indicated that stress on the school, home, social relationships, and self has the more significant influence on the school adjustment, and the locus of control has relatively low influence.

• 수산해양교육연구
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• 제29권2호
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• pp.492-502
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• 2017

The purpose of this study was to verify the influences of surfing participants' participation motivation on flow experience and continuous participation intention. The study conducted a research survey through purposive sampling method after selecting 2 surfing center in Ganwon-do. 280 questionnaires distributed and 269 were selected as final valid sample by removing 11 questionnaires that have insufficient answers. Then data were analyzed through exploratory factor analysis, reliability analysis, correlation analysis, and multiple regression analysis using SPSS Window ver. 20.0. The results were as followings. First, participation motivation factors have positive effect on flow experience. Second, participation motivation factors have an influence on continuous participation intention. Third, flow experience have an influence on continuous participation intention. Fourth, leisure flow have an influence on continuous participation intention.

• 수산해양교육연구
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• 제23권4호
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• pp.582-595
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• 2011

The purpose of the study was to investigate the causal relations among attachment, and social support influencing problem behavior in middle school students. The data contains 482 middle school students. Collected data were analyzed using SPSS and AMOS statistical package for correlation analysis and structural equation modeling. Study results were as follows. The correlations among attachment, social support and problem behavior were significant. The results of the structural equation modeling show that students' social support had direct positive influence on problem behavior, but students' attachment didn't have direct positive influence on problem behavior. That is to say, social support mediated the effect of attachment on problem behavior. These results imply that perceived attachment, and social support influence adolescents' problem behavior. Results suggest that programs that promote social support should be given to reduce problem behaviors of middle school students.

• 수산해양교육연구
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• 제23권1호
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• pp.116-125
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• 2011

In this study, a survey research was conducted on government employees in Busan Metropolitan City to identify the influence of cyber education factors (learning factor, learner factor, and learning system factor) on the preference for government employee cyber education offered by the government always learning system. Analyzed results, recognition of learning factor, learner factor, and always learning system were shown to have significant influence on the preference for cyber education, but no indication of influence by always learning support. This study intends to assist stimulating voluntary participation in cyber education and active commitment in learning activities through improving learning effect and fortifying convenient informatization education, with regard to activation of cyber education and improved preference for cyber education.

• 유통과학연구
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• 제17권12호
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• pp.43-54
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• 2019

Purpose: Marine transportation companies must improve service quality to secure competitive advantage and continuous relationships with customers. This study explores the value and necessity of service quality in the industry by empirically identifying the factor that would have the largest effect on the improvement of service quality, also examining whether such improvement may actually influence continuous relationships. Research design, data and methodology: Based on an online survey with those in the Korean marine transportation industry, this study conducted statistical analyses using structural equation modeling. Based on relevant previous studies, the current study constructed a total of 55 survey questions. Finally, 281 questionnaires were collected, but 68 were excluded owing to invalid responses. Results: Information service attribute had the largest effect on service quality, whereas communication did not demonstrate a significant influence. In addition, distribution and information services exerted a positive effect on service satisfaction through service quality, and finally influenced relationship continuity. Conclusions: The results shows that marine logistics service quality strategies which were centered on time or local factors, should be considered in terms of the development of innovative services. In particular the improvement of information service systems and strategies in changed business environment.

• 동력기계공학회지
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• 제22권1호
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• pp.25-33
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• 2018

The safety of structure was evaluated by taking into consideration the complex marine environmental conditions of the Lattice boom crane, which is widely used in offshore plants due to less influence by wind. CFX analysis was carried out to take into account the influence of wind speed, and the result was applied as a boundary condition to perform static analysis according to the luffing angles of $28^{\circ}$, $61^{\circ}$, and $80^{\circ}$ in the on board and off board, respectively. In addition, the Lattice Boom Crane is large slender structure, and the possibility of buckling is interpreted under three conditions where the biggest stress occurs. All conditions satisfied the safety requirements of the Classification Regulations. Also, as a result of the buckling analysis, the load less than the critical load was applied so buckling does not occur.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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• pp.90-94
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• 2001

A Waterjet has been widely used for the propulsion of various speed range of marine vehicles due to its many advantages compared with the conventional screw propellers. In this paper, a power prediction based on momentum flux method is presented for the preliminary estimation of required power and selection of propulsion system for the waterjet driven craft. A theoretical basis of the mechanism of the waterjet is given and some of the empirical formulas are given as well. Finally the influence of intake type and nozzle exit velocity on the efficiency will be discussed.

• Journal of Advanced Marine Engineering and Technology
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• 제38권8호
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• pp.968-973
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• 2014

Aluminum anode of marine growth prevention system for ship is installed in seachest or sea water strainer. The Al anode is connected to a control panel that feeds a current to the anode. The dissolved ions produced by the anode are transferred in sea water, spreads through the sea water pipe system and creates a protective film in the pipelines. Thereby, corrosion in pipeline system significantly is reduced. In application on condition as a steel ship, the big accident can be caused by the corrosion. Accordingly, in this research, we evaluated influence of applied current and flow velocity on electrochemical characteristics of Al anode for marine growth prevention system (MGPS). Based on the results of the erosion-cavitation experiments, cavitation rate increased greatly until 120 min. of the experimental time and decreased a little at the point of 180 min. where pit grew and merging occurred but showed a tendency of steadily increasing consumption rates. Based on the results of the Tafel analysis, compared to static states, corrosion current densities show a rapidly increasing tendency when flow occurred.

• 수산해양교육연구
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• 제18권3호
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• pp.329-340
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• 2006

The purpose of this research is to know the influence of high school students' activities of Marine Sports on the development of their sociality by comparing students in this activities with those who are not in this activities. The objects of this research are high school students who live in Busan at present. The total number of the object is 146, including 74 students who participated in this organization and 72 students who didn't participate in this organization. We have reached the following conclusion after analyzing the materials according to the methods and procedures of the research. In the domain of activity, the students who are in Marine sport activities are statistically different from those who are not. In the domain of stability, the students who are in Marine sport activities are meaningfully different from those who are not. In the domain of ascendancy, the students who are in Marine sport activities are meaningfully different from those who are not. In the domain of sociability, the students who are in Marine sport activities are meaningfully different from those who are not. In the domain of self-control, the students who are in Marine sport activities are meaningfully different from those who are not.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1060-1065
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• 2005

An Independent Administrative Corporation Japan Agency for Marine-Earth Science and Technology (JAMSTEC) is developing light-and-small Autonomous Underwater Vehicles (AUV)$^{1)}$, named 'MR-X1' (Marine Robot Experimental 1), which can cruise, investigate and observe by itself without human's help. In this paper, we consider the motion control problem of 'MR-X1' and derive a controller. Since the dynamic property of 'MR-X1' is changed by the influence of the speed, the mathematical model of 'MR-X1' becomes the nonlinear model. In order to design a controller for 'MR-X1', we generally apply nonlinear control theories or linear control theories with some constant speed situation. If we design a controller by applying Linear Quadratic (LQ) optimal control theory, the obtained controller only compensates t e optimality at the designed speed situation, and does not compensate the stability at another speed situations. This paper proposes a controller design method using Linear Matrix Inequalities (LMIs)$^{2),3),4)}$, which can adapt the speed variation of 'MR-X1'. And examples of numerical analysis using our designed controller are shown.