• International Journal of Ocean System Engineering
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• v.3 no.1
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• pp.10-15
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• 2013

A ship cruising in the ocean oscillates continuously due to wave action. In order to reduce the ship's roll, we developed a fin stabilizer as an anti-rolling device for a 500-ton-class high-speed marine vessel. During the development phase, it was necessary to set up control gains for the motion and hydraulic systems and assess the effectiveness of the anti-rolling performance on the ground. For this reason, a Target Simulator, which simulated the ship's motion, was given operator inputs such as the engine telegraph and waterjet deflection angle, and generated roll using a one-degree-of-freedom motion base. Hardware-In-the-Loop Simulation (HILS) was performed using the Target Simulator in order to confirm the various logics of the developed fin stabilizer, select initial control gains, and estimate the anti-rolling performance. In conclusion, it was confirmed that HILS was very helpful to develop the fin stabilizer because it could reduce the number of sea trial tests that were needed and could find many malfunctions in the factory a priori.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.1
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• pp.74-81
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• 2017

A crane is typically used as a means to lift and load equipment or materials. A surface vessel uses a towed object for underwater activity. Such a mechanism for dropping and lifting of equipment is necessary, and is called an overboarding unit. The present study is focused on the overboarding unit used for a crane structure. This paper deals with new overboarding mechanism design and GA-based $MATLAB^{(R)}$ optimization. By using a quadrilateral link mechanism, it is possible to set the constraint function for optimizing the GA method. The optimization with $MATLAB^{(R)}$ is followed by the $SolidWorks^{(R)}$ simulation and verification. When applying the proposed mechanism, the operator is expected to have a big advantage in safety and efficiency of operations. Furthermore, the technology developed in this study will be helpful in similar circumstances and in the proposed mechanism.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.07a
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• pp.316-318
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• 2015

The efficient utilization of VTS console functions in terms of user helps carry out VTS tasks successfully. All the console functions for VTS operation have been surveyed. The default functions used in current VTS console are evaluated by VTS operation, Most popular functions are categorized, and the other functions for the advanced VTS services are suggested. The result of research expect application possibility when designing of GUI.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.261-267
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• 2015

A support system which allows operator to check the condition of a vessel and to warn the sea risk in order to prevent accidents of leisure boats, is required. Therefore, this paper proposes a navigational safety support system to ensure the safety of vessels by monitoring and managing the status of those ships. In developing a system process, each developed equipment is integrated and verified whether the functional, compositional and operational algorithms are working properly according to the designed object.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.4
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• pp.667-674
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• 2004

This thesis is about the Impressed Current Cathodic Protection (ICCP) control and monitoring system. which brings protection against the corrosion of the ship's hull in the sea environments. The ICCP system is composed of a power supply. anode. reference electrode and controller. AC sources from the ship's generator are converted to DC sources in terms of power supply, and a protection current is sent to ship's hull though anode. The controller fully senses whether or not the detected potential is within a range of protection of ship's hull and then it is automatically controlled to increase or decrease the amount of protective current to be sent to the anode. The monitoring system with RS 232/485 communication is also studied in order to check the normal state of the system at a long period. because an operator does not always watch over this system and thus the system cannot operate well because of his or her negligent management. Since the vessel always navigates in the sea. an characteristics experiment of the ICCP system is conducted by introducing various corrosive environmental factors such as velocity, resistivity, dissolved oxygen, PH, temperature and contamination degree. These results must be referred to when the ICCP system is set up. In short. the ICCP is a multi-system for use on ships and on land structures because it includes a safety device. It is suggested that this system can accomodate a ship's automation and will be very useful.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.6
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• pp.685-692
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• 2003

A numerical simulation of flame propagation in a micro combustor was carried out. Combustor has a sub -millimeter depth cylindrical internal volume and axisymmetric one-dimensional was used to simplify the geometry. Semi-empirical heat transfer model was used to account for the heat loss to the walls during the flame propagation. A detailed chemical kinetics model of $H_2/Air$ with 10 species and 16 reaction steps was used to calculate the combustion. An operator-splitting PISO scheme that is non-iterative, time-dependent, and implicit was used to solve the system of transport equations. The computation was validated for adiabatic flame propagation and showed good agreement with existing results of adiabatic flame propagation. A full simulation including the heat loss model was carried out and results were compared with measurements made at corresponding test conditions. The heat loss that adds its significance at smaller value of combust or height obviously affected the flame propagation speed as final temperature of the burnt gas inside the combustor. Also, the distribution of gas properties such as temperature and species concentration showed wide variation inside the combustor, which affected the evaluation of total work available of the gases.

• Journal of Fisheries and Marine Sciences Education
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• v.24 no.6
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• pp.872-883
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• 2012

Generally the determination of turning basin for vessels of entering & sailing in the berth has been considered in the design standard of harbor construction rules of the port. In this regard, the turning basin has been determined by the max size of entering vessel of the berth/port. But the size of turning basin may considered the ship's maneuvering ability, operator's skillful power, mooring equipments of the berth, arrangement of the fairway and the environment condition of weather & seas around the designated port area. So this paper suggested the optimum size of turning basin after studying the harbour design rules of the advanced marine countries and using by maneuvering simulator for turning basin size and also evaluated the design standard of harbor construction rules and minimum size of turning basin against ship's length at the Gangjung civil/naval port of Jeju Island.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2772-2774
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• 2000

According to the development of marine transportation business and the modernization and over sizing of vessel transportation equipment. shipping equipment used in the terminal are getting more atomized and speedier. thus the efficiency of shipping and discharging depends upon the degree of practice of terminal operating manpower. It means that cultivation of experts in this field is essentially needed and it is becoming a serious problem to guarantee the training programs to provide high-class. high-skilled manpower. The best result can be expected when we use the real equipment for training purposes. but it will cause many difficulties such as budget problem. To overcome this situation. we developed the Virtual Container Crane Simulator(VCCS System) which enables the operator to learn the operation of the equipment as well as safety problems within a short time. VCCS system begins with establishing the direction of operation by setting the appropriate motions for each step. and then it instructs the basic operation. It enhances the driver's ability to cope with accidents during operation and completes and completes the mastery of operating techniques with The repetition of practice.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.2
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• pp.179-188
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• 2009

WIG crafts are a high speed vessel with features of dynamic supported craft. These crafts, which are predominantly of light weight and operate any substantially greater speeds than conventional craft such as bulk carrier, tanker, container ship, etc., could not be accommodated under traditional maritime safety instruments. It means that there is the need for risk and safety levels to be assessed on a holistic basis, recognizing that high levels of operator training, comprehensive and thoroughly implemented procedures, high levels of automation and sophisticated software can all make significant contributions to risk reduction. To response this requirement, the Interim Guideline for WIG craft(MSC/Circ.1054) were developed in the view of the configuration of WIG craft, which fall between the maritime and aviation regulatory regimes. This paper reviews a safety assessment process and methodology to be used in the design phase of a new ship. The process and methodology is based on the risk-based approach and is applied to safety assessment in concept development phase of small WIG craft in the 20-person class.

• The Korean Journal of Nuclear Medicine
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• v.33 no.2
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• pp.131-142
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• 1999

Purpose: Either gated myocardial perfusion SPECT or attenuation corrected SPECT can be used to improve specificity in the diagnosis of coronary artery disease. We investigated in this study whether gating or attenuation correction improved diagnostic performance of rest/stress perfusion SPECT in patients having intermediate pre-test likelihood of coronary artery disease. Materials and Methods: Sixty-eight patients underwent rest attenuation-corrected T1-20l/dipyridamole stress gated attenuation-corrected Tc-99m -MIBI SPECT using an ADAC vertex camera (M:F=29:39, aged $59{\pm}12$ years, coronary artery stenosis ${\geq}70%$, one vessel: 13, two vessel: 18, three vessel: 8, normal: 29). Using a five-point scale, three physicians graded the post-test likelihood of coronary artery disease for each arterial territory (1:normal, 2: possibly normal, 3:equivocal, 4. possibly abnormal, 5: abnormal). Sensitivity, specificity and area under receiver-operating-characteristic curves were compared for each operator between three methods : (A) non-attenuation-corrected SPECT; (B) gated SPECT added to (A): and (C) attenuation-corrected SPECT added to (B). Results: When grade 3 was used as the criteria for coronary artery disease, no differences in sensitivity and specificity were found between the three methods for each operator. Areas under receiver-operating-characteristic curves for diagnosis of coronary artery disease revealed no differences between each modality (p>0.05). Conclusion: In patients at intermediate risk of coronary artery disease, gated SPECT and attenuation- corrected SPECT did not improve diagnostic performance.