• Journal of Advanced Marine Engineering and Technology
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• v.33 no.8
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• pp.1268-1274
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• 2009

Various evaluation systems using simulators have been adopted widely for the purpose of training and examination, including marine engineering education area. This paper suggests a PC based evaluation scoring system for simulators where the operation ability of machineries and background knowledges of trainees or examinees are able to be assessed relatively. The scores are based on the 100 point resulted from their responses for a given evaluation scenario under a PID tuning simulation. The mistakes they make during the operation time are integrated firstly to get error sum, and the error sum is transformed secondly to 100 point score according to a formula where the knowledge level of examinee's groups can be compensated and considered reasonably. The implementation result of evaluation system for the given control loop is described and analyzed to show the effectiveness of the suggested configuration as an evaluation tool.

• Journal of Navigation and Port Research
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• v.33 no.9
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• pp.635-644
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• 2009

The optimum design of power yacht belongs to the nonlinear constrained optimization problems. The determination of scantlings for the bow structure is a very important issue with in the whole structural design process. The derived design results are obtained by the use of real-coded micro-genetic algorithm including evaluation from Lloyd's Register small craft guideline, so that the nominal limiting stress requirement can be satisfied. In this study, the minimum volume design of bow structure on the power yacht was carried out based on the finite element analysis. The target model for optimum design and local structural analysis is the bow structure of a power yacht. The volume of bow structure and the main dimensions of structural members are chosen as an objective function and design variable, respectively. During optimization procedure, finite element analysis was performed to determine the constraint parameters at each iteration step of the optimization loop. optimization results were compared with a pre-existing design and it was possible to reduce approximately 19 percents of the total steel volume of bow structure from the previous design for the power yacht.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.298-305
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• 2015

This paper provides experimental results of an excitation control system of the synchronous generator on board ships in accordance with rules of classification society to make sure its performance. The experiment compares and reviews control results between PID control and fuzzy logic control applied to change of loads of the generator in order to make sure to satisfy the rules of classification society. Both of them are written by Labview program. In case of PID Control, this paper firstly adjusts the gains by ultimate sensitive method and the gains is more tuned by engineer's experience. And the fuzzy logic controller uses Mamdani method to make membership function for error between reference voltage and measuring voltage, differential error rate and output voltage. This paper is to make sure the experimental results of the proposed excitation control system applied to actual small synchronous generator with PID control and fuzzy logic written by using Labview program and it is proved on stability and improvement through experiments.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.6
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• pp.878-884
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• 2015

In this paper, Power Management System(PMS) simulator for Liquid Nature Gas Carrier(LNGC) is developed. Major components of power system for LNGC, such as generator, diesel engine and governor, transformer, circuit breaker, and 3 phase loads models are built based on MATLAB/SIMULINK. With these designed major parts, PMS simulator modeling is carried out. Based on MATLAB/Graphical User Interface, PMS simulator control for LNGC, and Human Machine Interface for monitoring is designed. PMS simulator for LNGC carries out simulation according to sequence of characteristics analysis. By comparing results of predicted simulation for each sequence to that of characteristics analysis, the reliability of PMS simulator for LNGC will be verified.

• Journal of the Korean Professional Engineers Association
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• v.28 no.4
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• pp.21-32
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• 1995

Tideland Reclamation Projects, which have played a significant role in selfsuffficieny of food in Korea, are being greatly restricted nowadays in their implementation due to their demands of big amount of construction costs and their severe malfunctioning of contaminat-ing the marine environment. Under the situation, this paper was prepared not only to stimulate the Government to continue the imlementation of new tideland reclamation projects, but also to contribute to the development of tideland reclamation technology by which the construction costs and rnalfunctionings could be minimized. Eventhough, the functioning of filters is considered to be important for the safety of seadikes, their planning and design are being made unreasonably In view point of construc-tion cost and strutural safety. Therefore, a reliable planning and design method for filters is presented in this paper on the basis of filter theory. In this way, we professional engineers corncerned should endeavor to develop more ad-vanced technology, by which the Government would implement the tideland reclamation projects continuously to supply the land and water more steadily in time.

• Journal of the Korean Professional Engineers Association
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• v.43 no.2
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• pp.34-38
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• 2010

The Busan-Geoje Fixed Link is an 8.2 km long motorway connecting Busan to the island of Geoje where the Korean big two shipbuilding yard locate on. This motorway includes a 3,300m immersed tunnel which is one of the longest immersed tunnel in the world and two cablestayed bridges each of 2km in length. The site locates in a exposed offshore, which is subjected to strong winds, large swell waves and strong tidal currents. These conditions together with the tunnel being at a deepest immersed tunnel ever built and the foundation condition is consisting of a very soft, normally to slightly over consolidated marine clay, makes the project unique and one of the most challenging immersed tunnels ever built.

• Journal of the Korean Professional Engineers Association
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• v.12 no.4
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• pp.26-31
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• 1979

The Natural Gas and petroleum have the same Origin, Namely, Ocean bottom deposits of the marine plant, plankton which are subdued to the biological action of the bacterium under the anaerobic circumstance, and changed to the hydrocarbon gas and oils. and such resources are appeared in the aqueous sedimentary rocks in the tertiary. There are three types of gas field, which are oil well gas field, structural gas field and water soluble gas field.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.363-368
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• 2021

Ship engine rooms have improved automation systems owing to the advancement of technology. However, there are many variables at sea, such as wind, waves, vibration, and equipment aging, which cause loosening, cutting, and leakage, which are not measured by automated systems. There are cases in which only one engineer is available for patrolling. This entails many risk factors in the engine room, where rotating equipment is operating at high temperature and high pressure. When the engineer patrols, he uses his five senses, with particular high dependence on vision. We hereby present a preliminary study to implement an engine-room patrol robot that detects and informs the machine room while a robot patrols the engine room. Images of ship engine-room equipment were classified using a convolutional neural network (CNN). After constructing the image dataset of the ship engine room, the network was trained with a pre-trained CNN model. Classification performance of the trained model showed high reproducibility. Images were visualized with a class activation map. Although it cannot be generalized because the amount of data was limited, it is thought that if the data of each ship were learned through transfer learning, a model suitable for the characteristics of each ship could be constructed with little time and cost expenditure.

• Journal of Fisheries and Marine Sciences Education
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• v.4 no.2
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• pp.109-120
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• 1992

The auther reported the distribution of fisheries high schools and arrangement of curriculum in Japan in the forward report, and describes on the outer apparance and substantiality of education of fisheries high schools in Japan in the present report. 1. The rate of population to the number of fisheries high school shows 2,350 thousands in Japan, compared with 3,250 thousands in Korea. Then the rate in Korea is 1.4 times as high as that in Japan. 2. The rate of pupil to the whole regular instructors for fundamental subjects and for vocational subjects in the fisheries high schools, and also the rate to the instructors for vocational subjects show 10.4 and 16.3 in Japan, compared with 18.2 and 30.2 in Korea. Then the rate in Korea is 1.8 times as high as that in Japan. In addition to the instructors for vocational subjects. trainer and assistants for technical training-are employed in Japan compared with no such instructors or assistants in Korea. Then the rate of pupil to the whole instructing staffs in Korea is 2.4 times as high as that in Japan. 3. 81 percents of training ships in Japan are larger than 400 gross tons, which is extremely higher to that in Korea. The rate of gross tonnage of the ships to the number of trainees shows 6.2 tons in Japan compared with 1.1 tons in Korea. Also such large dimensioned training ships are newly built every other 12 years. the construction cost per 1 gross ton of such ships are said as 2.5 to 3 million yen, which corresponds to 15 to 18 million wons, and is over 3 times as much as that in Korea. 4. The basic education on the marine field is widely diffused in Japan. For an example, swimming pools are prepared not only in fisheries high schools but also in primary schools although it is rate even in fisheries high schools or colleges in Korea. 5. Almost all provinces which locate on the seashore have at least one fisheries high school and the curriculum is arranged to match the needs of local districts, then the management of school is tightly linked to the local government. 6. Entrance system is also flexible and recommended entrance system for successors of fishermen is settled. 7. Re-education of instructors for the new subjects which should be prepared to match the demands of ages are supported by local government in the aspect of time and budget. 8. The special two-year course for advanced seamen' s education is attached to some fisheries high schools and the graduates are qualified to get the third grade marine officer's or engineer's liscence.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.5
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• pp.334-342
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• 2013

In this paper, we analyze the procedure of the design manager for the enhancement of the hull production design process by use of the simulation method. Normally, design manager assigns design jobs according to various methods and estimates the corresponding results. When the construction drawing which is the output of the detail design where a design is dealt by zones, the design manager identifies blocks and analyzes their work difficulties, and assigns jobs to design engineers who are different in capabilities. These processes including the design engineer who can be modeled with man-hours evaluation model are represented in detail as a simulation model. As the high-level modeling for the discrete-event system, we use Event Graph model. And we implemented the simulation using Simkit which is open simulation engine for the discrete-event system. We made the simulation scenario to be written by a user in the scenario generator which is separated from the simulation model, and made the simulation result to be visualized in the form of Gantt chart in a Web. In the scenario of the irregular issuance for various construction drawings which contain different numbers of blocks, we performed the Monte-Carlo simulation according to various assignment methods to find the assignment result that satisfies the mid-term schedule.