• Journal of Advanced Marine Engineering and Technology
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• v.31 no.4
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• pp.433-440
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• 2007

In this paper a new dynamoelectric winch system is introduced which is widely applied in shipping. building, architecture and so on. Generally in the winch system the squirrel cage induction motor is used as prime mover and line voltage is directly applied to the induction motor during operation. So it is difficult to obtain the smoothing revolution. because of variation of the weight of cargo and system operating method. Based on above reasons, the switched reluctance motor (SRM) is proposed to replace the induction motor because of more reliable mechanical structure, better traction characteristic and higher efficiency compared to induction motor. And in order to solve smoothing revolution problem, instantaneous torque control method based on torque sharing function (TSF) is used. Finally the validity of the proposed method is verified through the simulation and experimental results.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.3
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• pp.611-626
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• 2014

Based on adolescents' perspectives, this study attempts to explore the distinguishing characteristics of teachers that influence students to positively change in areas such as psychological adaptation and development of their potential. Essays focusing on memories of twenty seven significant teachers written by eighteen adolescents in middle schools and high schools in Daegu, Korea in 2011 were used for analyzing the factors that have influenced them to positively change. Subsequently, five critical factors were identified: warmness and acceptance; encouragement and support; communication and understanding; respect and care; modeling and expectation. The adolescents perceived that those factors not only contributed to their psychological wellbeing but also enabled them to positively change and achieve more in life. Moreover, the educational implications focusing on teachers' productive function and healing power were discussed. The role of teachers in reinforcing and building the character students in order to facilitate their holistic development was dealt with. Finally, the reference for promotion of further studies of the research field was made.

• Proceedings of KOSOMES biannual meeting
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• 2005.11a
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• pp.133-137
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• 2005

To investigated the variation of marine environments due to set up of artificial structure, we carried out field observations. High temperature and salinity waters were distributed clearly in the southeastern part of study area during summer season. The variation of current structure was also occurred around study area where artificial structure set up. In 2005 after set up of artificial structure, the nutrient concentration increased greater than that in 2002 before set up artificial structures. To illustrate the characteristics of marine environment due to set up of artificial structure, quantitative analyses on the effect of artificial structure are important.

• Journal of Advanced Marine Engineering and Technology
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• v.8 no.2
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• pp.51-66
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• 1984

The cost percentage of engine part in the total building cost of a ship is about 30-40% and the main engine occupies about 50% of the engine part cost. For certain ships the fuel bill can be as high as about 60-70% of the total operating cost after two oil shocks and its amount for one year is nearly equivalent to her main engine price. This fact has further increased the pressure on the engine builders to develop engines of higher efficiency and better possibilities to burn further deteriorated fuel qualities. But the energy-saving plants are ordinarily more expensive and their available amount of exhaust gas energy is less and therefore, they are not always profitable and optimum systems. This paper is prepared to decide the most economical and efficient engine systems by presenting reasonable selecting and economical evaluation methods of the main engine, which is the largest single unit and the most expensive, and its auxiliaries. In order to demonstrate the application of investigated methods in a practical case, a 46, 000 DWT class bulk carrier is selected as a model ship and her main engine and its auxiliaries are selected and evaluated. The result shows that the optimum determined has one year three months POP, 0.903 IRR at a year, 4, 116, 000 dollars PW in 15 years (for 5% escalation rate of fuel cost) and 9.522 BCR for same condition, when the engine plant of a same existing ship is taken as the basis.

• Fisheries and Aquatic Sciences
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• v.9 no.4
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• pp.167-174
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• 2006

Two typical responses have been documented for flatfish when they encounter the ground gear of bottom trawls: herding response and falling back response. These two responses were analyzed from video recordings of fish and were characterized by time sequences for four parameters: swimming speed, angular velocity, acceleration, and distance between the fish and the ground gear. When flatfish displayed the falling-back response, absolute values of the three swimming parameters and their deviations were significantly higher than those during the herding response. However, the swimming parameters were not dependent on the distance between the flatfish and the ground gear, regardless of which response occurred. The dominant periods for most of the movement parameters ranged from 2.0 to 3.7 s, except that no periodicity was observed for swimming speed or angular velocity during the falling-back response. However, variations in the four parameters during the falling -back response revealed greater irregularity in periodicity and higher amplitudes. This complex behavior is best described as a chaos phenomenon' and is discussed as the building block for a model predicting the responses of flatfish to ground gear as part of the general understanding of the fish capture process.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.3
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• pp.362-371
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• 2009

Shipbuilding is a typical 'build to order' industry. It has a business model that generates revenues from building various ships and offshore products in accordance with owner's requirements at each production stage. Under uncertainty in shipping market, it is very essential for the shipbuilder to prepare the fast and competitive decision for product portfolio strategy in order to maximize contribution margin by exploiting production facilities and constraints. In this study, we introduce the unique decision supporting methodology for the optimal product portfolio sets based on Theory of Constraints(TOC). This methodology is established by adopting the concept of Drum Buffer Rope(DBR) in constraints planning and Throughput Accounting (TA) in management accounting of TOC. In addition, Decision Supporting System(DSS) is implemented. This DSS system provides a throughput estimator with reflecting the cost structure of shipbuilding industry and a resource simulator built on heuristic algorithms to operate major constraint-resources in shipyard such as dock, quay and pre-erection area etc. Several examples are presented to show that the proposed methodology and system can effectively support the strategic decision-making process of a global shipbuilding company.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.4
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• pp.403-408
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• 2014

Lots of electric power has been wasted through the load bank usually in the container boxes during the generator load test of the ship and offshore plant in the new ship building. Therefore in this research, the quantity of wasted electric power through generator load test under construction was investigated on big shipbuilding yard and quantity of electric power that can be recovered is analyzed when produced electric power during the generator load test is connected to KEPCO Grid, according to laboratory's experiment result where recovers electric power produced from small generator connected to KEPCO Grid.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.120-121
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• 2013

Recently, our country is to be diversification a leisure activity and tourism form by income level rise and traffic circumstance improvement. But Basic facilities expropriated these leisure activities have built an insufficient condition. Also, Building a facility, Introduced tools and materials import the whole quantity. Therefore, In this paper, it builds a tension mooring unit to use EPDM and Kevlar R29 and it develops a domestic marine circumstance through reliability based on robust design. It contributes to marine leisure culture activation and industry development.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.05a
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• pp.234-235
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• 2019

Smart Maritime Autonomous Surface Ship(MASS) is aiming to provide eco-friendly smart maritime navigation service based on safety, reliability and efficiency for maritime safety and marine environment protection. In the future, it is expected to bring about a radical change across the marine industry such as marine, maritime, port, logistics, ship-building and so forth. Therefore, in this paper, policy priorities related to the introduction of MASS were identified, and response strategies for each industry were set up, and a policy plan for establishing a smart maritime logistics system covering shipping, port and shipbuilding fields was proposed.

• Journal of Ocean Engineering and Technology
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• v.37 no.5
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• pp.190-197
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• 2023

In the shipbuilding and marine industry, digital transformation activities are promoted primarily by large shipyards. However, bottlenecks are observed across value chains, and digital transformation effects are reducing because of the cost and technical challenges encountered by supplies. In this study, we proposed a win-win cooperation model for large, small, and medium-sized companies using digital transformation based on the characteristics of the shipbuilding and marine industry through case studies. We investigated the digital transformation progress in German and Korean small and medium-sized enterprises (SMEs). In addition, we identified information-sharing methods and management challenges encountered in enterprise resource planning and manufacturing execution systems in the collaboration process of pipes, panels, blocks, etc. of SMEs that are suppliers of a Korean shipyard, and clarified communication by building a platform based on a common format between shipyards and suppliers. Further, we proposed a standard model of a digital transformation system for enhancing the collaboration between large companies and suppliers and proposed a basic plan including strategies to efficiently and effectively build a digital transformation system based on the standard model.