• Journal of Advanced Marine Engineering and Technology
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• v.17 no.4
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• pp.87-99
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• 1993

Nowadays, the cartridge valve can be controlled proportionally in remote place by adopting proportional solenoid and it becomes widely used as control component in hydraulic systems. Especially, multi stage proportional valve is attractive because it consumes less input power though its characteristics might slightly be defected. But, the system parameter should be carefully chosen to obtain optimistic characteristics. This study concerning three stage proportional throttle control valve is purposed to examine the influences of paameters to the dynamic characteristics. The typical transient and frequency responses of proportional throttle control valve were inspected through the experiments and compared to those derived from the theoritical analyses. And it was confirmed that the analyses are appropriate. Then the influences of various system parameters to the dynamic characteristics were examined by means of simulations. For the analyses, the basic equations derived from lumped model were linearized and the linearized equations were transformed to the transfer functions between inputs and outputs. Then the transient responses and frequency responses were obtained from transfer functions. 1. It is appropriate to estimate the dynamic characteristics of valve which has relatively sophisticated structure by means of system analyses using linearized equations. 2. Though the valve has two pilot stages, fairly good characteristics can be obtained by carefully choosing system parameters. 3. Main valve very quickly follows the movement of second pilot valve when the parameters of main valve(the oil supply passage and discharge passage fpr second pilot valve) are appropriately chosen.

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.49-49
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• 2018

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.3
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• pp.293-301
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• 2002

MGF(Marine Geographical Framework) data are the essential data sets concerning graphical and attribute information on coast and ocean among various marine-related data, which consist of framework data of the National Spatial Data Infrastructure(NSDI). This study did research and analyzed the development of current data, the situation of its usage, related technical environment and case study of foreign countries through the survey on the users and experts. Then the item of marine geographical framework data was selected in accordance with the measures for usage and management of possible MGF data. A map was pilot producted based on selected items and MGF data was presented through making up some problems shown ill the process. The importance of GIS will be growing continuously which can develop, deal with and provide the various data to efficiently manage coast and ocean. Accordingly, the MGF data will be applied to various areas such as Internet or raw data for marine information system.

• Sleep Medicine and Psychophysiology
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• v.25 no.2
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• pp.58-67
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• 2018

Objectives: The purpose of this pilot study was to examine the effects of a mindfulness-based Body-Mind Intervention Program using marine resources on the improvement of quality of sleep, mood symptoms, and cognitive function in Korean female emotional labor workers. Methods: Twelve female workers who experienced excess emotional labor participated at the training camp program for five days in Danghangpo-ocean park, Goseung-gun, Gyeongnam Province in South Korea. Participant sleep quality, mood symptoms, and cognitive functioning before, after, and 1.5 months later were evaluated and analyzed. Results: After participating in the marine resource program, participants reported significantly decreased sleep latency. Global sleep quality, cognitive functions (attention, flexibility, and inhibition control), and mood states, including depression, tension, anger, fatigue, were also improved. These effects were generally maintained after 1. 5 months (PSQI t = 2.63, p = 0.02 ; HAM-D t = 5.92, p < 0.001). Conclusion: A Body-Mind Intervention Program using marine resources was effective in relaxing emotion-related tension and improving cognitive function. To advance this pilot study, it is necessary to carry out further research to investigate the use of marine resources in mental health interventions.

• Journal of Navigation and Port Research
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• v.47 no.6
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• pp.341-349
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• 2023

Gamcheon Port, which is one of three major harbors in the Port of Busan, is being operated to load, discharge and transport a wide range of cargoes, including general cargo, fisheries, steel products, cement, etc,. The harbor, designated as a compulsory pilotage area, provides pilotage services in compliance with relevant laws and regulations for arrival and departure of vessels in the Gamcheon Port area. Some academic research on the marine traffic environment in Gamcheon Port has been conducted. However, the pilotage environment and hazards to pilotage safety in the port have yet to be studied. Therefore, in this research, the pilotage environment and hazards to pilotage safety were identified, and it was confirmed that there are hazards to pilotage safety, such as vessels installed poor facilities including damaged pilot boarding arrangements, vessels blocking pilot's view by her structures and fishing nets, vessels unable to communicate in English, vessels not following VTS's order. The hazards to pilotage safety were also stratified, and the importance of the hazards was verified in accordance with a survey based on Analytic Hierachy P rocess(AHP) for Busan Harbor pilots, and safety measures to secure pilotage safety were examined to secure the safety of vessels calling Gamcheon Port.

• Journal of Advanced Marine Engineering and Technology
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• v.18 no.4
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• pp.13-24
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• 1994

The demand of clean energy, like liquefied gas(LNG), increase suddenly because it generates few polluting substances when burned and from the point of view with caloric value it generates ralatively less $CO_2$ gas than the other energy sources. LNG transpotion method of our country is marine transportion by ships because the LNG producing district is far away from Korea. Main engines for most LNG ships are steam turbines, and the efficiency of steam turbine is influenced by the degree of vacuum of main steam condenser. This paper introduce the design method of the vacuum system for high efficiency marine steam turbine. Especially, it is developed the CAD program for the large steam condenser and steam ejector. Also, it is designed the pilot plant including high pressure boiler for the performance test and maked a part of this plant.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.66-66
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• 2017

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.8
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• pp.1045-1050
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• 2006

Optimum operation condition for pilot scale of alkaline processing for fish muscle was investigated by measuring protein solubility, yield, texture, and water-holding capacity. Recovered protein yield was 33.2% for whole fish and 61.8% for minced muscle. Optimum homogenized speed and time, using industrial scale homogenizer, were 3,000 rpm and 5 min, respectively. Limited centrifugal force of continuous cylinder type was 4,000 rpm for recovering soluble protein, and 2,000 rpm for recovering precipitated proteins. The pH control agents such as citric acid, sodium phosphate and calcium oxide decreased the breaking force and deformation of recovered protein gel. The breaking force and deformation of the recovered proteins were high compared to conventional surimi. The breaking force and deformation were decreased by addition of salt, starch and bovine plasma proteins. Whiteness of recovered protein gel was lower than that of conventional surimi. Alkaline processing greatly decreased nitrogen content and chemical oxygen demand in waste water. The results suggest that alkaline processing has a potential as industrial production for recovering the proteins from fish muscle.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.08a
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• pp.167-176
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• 2004

The authors have newly developed the “Port Traffic Management System (PTMS)”. The PTMS provides each ship with the detailed planned routes of all the ships entering/leaving the port. This system also has a function to predict the encounter situations between own ship and other ships in the future. Based on information of the present positions, speeds and planned routes of the own ship and other ships, it is possible to predict when and where the own ship will have dangerous encounters with other ships in the future. The software of PTMS was developed from 2001. Then onboard experiments using small training ships equipped with actual AIS were performed in June 2003. From the results of these onboard experiments, the usefulness of PTMS was clarified. In addition to these onboard experiments, the effectiveness of PTMS was confirmed by comprehensive simulator experiments. In the simulator experiments, captains/pilot maneuvered a training ship/container ship in congested waters using PTMS. [t was assumed that all ships have PTMS and send their planned routes. After the simulator experiments, captains/pilot suggested that it is very beneficial if the optimal route of own ship can be automatically calculated. In response to this suggestion, software to calculate the optimal route of own ship using Dynamic Programming was developed. This software calculates the minimum time route from the present position to the destination keeping the danger of collision against other ships under predetermined level. From the result of calculations for multi-encounter situations, it was confirmed that the developed software can provide safe and time-saving route.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.2 s.29
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• pp.161-167
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• 2007

The goal of this paper is to develop the speech recognition system which can control the ship's auto pilot. The feature parameters predicting the speaker's intention was extracted from the sample wheel orders written in SMCP(IMO Standard Marine Communication Phrases). And we designed the post-recognition procedure based on the parameters which could make a final decision from the list of candidate words. To evaluate the effectiveness of these parameters and the procedure, the basic experiment was conducted with total 525 wheel orders. From the experimental results, the proposed pattern recognition procedure has enhanced about 42.3% over the pre-recognition procedure.