• Journal of the Society of Naval Architects of Korea
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• v.30 no.4
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• pp.8-16
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• 1993

Auto-Pilot System uses heading angle information via the position sensor and the rudder device to control the ship direction. Most of the control logics are composed of the state estimation and control algorithms assuming that the measurement device and the actuator have no fault except the measurement noise. But such asumptions could bring the danger in real situation. For example, if the heading angle measuring device is out of order the control action based on those false position information could bring serious safety problem. In this study, the control system including improved method for processing the position information is applied to the Auto-Pilot System. To show the difference between general state estimator and F.D.F., BJDFs for the sensor and the actuator failure detection are designed and the performance are tested. And it is shown that bias error in sensor could be detected by state-augmented estimator. So the residual confined in the 2-dim in the presence of the sensor failure could be unidirectional in output space and bias sensor error is much easier to be detected.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3184-3190
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• 2013

These days, the great part of design processes in the field of ship or offshore manufacturing are planed and implemented using the customized CAD system for each ship-building companies. It means that all information for design and production could be extracted and reused at the useful other area cost considerable time and efforts. The representative example is the estimation of welding length and material amount which is demanded during the construction of ship or offshore structures. The proper estimation of welding material to be used and the usage of them at the stage of schedule planning is mostly important to achieve the seamless process of production and expect the costing in advance. This study is related to the calculation of welding length and needed material amount at the stage of design complete utilizing the CAD system. The calculated amount are classified according to welding position, stage, block, bevel and welding type. Moreover it is possible to predict the working time for welding operation and could be used efficiently for the cost management using the results of this research.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.318-325
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• 2015

Korea has very strong shipbuilding industry in the world, so many new ships are constructed in Korean shipyards. These built vessels are carrying out sea trial at sea before delivering to shipowner, and sea trial ships cause navigation risk to other passing vessels to accomplish sea trial tests as quick turning, zigzag maneuvering and crash astern etc. in traffic congestion conditions. It occurred more than 1 collision accident related sea trial for recent 5 years. It has been increased about 30% of risk because of navigation of sea trial vessel by marine traffic flow simulation. This paper analyzed marine traffic density surveyed by AIS data for 7 days, and investigated position of marine accidents for 5 years in Korean coastal waterway, it established the sea trial prohibition areas as 10/100 level of total marine traffic volume, which is considered no danger for ship operator. This analyzed maritime safety law for setting of the prohibition waters to propose the basic legal system. It makes contribution to marine pollution prevention by setting of the sea trial prohibition water to improve the ship's navigation safety.

• Journal of the Korean Society of Marine Environment & Safety
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• v.2 no.1
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• pp.137-150
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• 1996

Safety is built in to the activities of the prudent ship operator. Ant investment made towards this end is likely to have a measurable payback in positive terms. That there must be an investment is inevitable, because the industry at large has let things slip too far too long. Those who have not allowed it to slip too far and who are the first to recognize that safety, far from costing money, in the long term actually preserves it, will be wieners. Too many seem to have lost sight of the fact that every one hundred pennies saved is a full one hundred pennies profit. Every hundred pennies of additional revenue contributes no more then fifteen pence to profit. Environmental protection is not so simple, nor so financially attractive. Man needs the minerals of the Earth as well as the products of the soil and sea survive. We(the human race) are still not in the position, politically or financially to manage the Earth's assets without causing damage. The evidence of our damage is evident in many different parts of the Glove and will in some cases haunt several generations still to come. We have learned a lot, and continue to learn, but despite the best intentions some Government needs for their people will be at the expense of people in another region for the foreseeable future. We sailors ply the seas with the raw materials of commerce as well as the finished and part finished goods. It does not always sit well to consider too deeply what effect the ship and the cargo it carries is having, or may have, on some communities, or on the sea through which sail. None my generation can hold up his head and claim to be without blame in the pollution of the seas. Times are changing though, and Governments are turning their attention more to the protection of our planet and its precious resources. This will not be without cost. The investment will have to be made not for our benefit, but for the benefit of generations yet to come, however the cost will have to be borne by society as a whole, not by the shipping community alone. The debate surrounding the choice between engineering our way to a better tomorrow, or adapting our working practices will continue. Each method has the same goal as its target and as long as we attain the goal does it really matter how we get there?

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.493-495
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• 2004

In this paper, shows a research in accordance with the design the implementation of the localization system for mobile robot using INS(Inertial Navigation System) and GPS(Global Positioning System). First, a Strapdown Inertial Navigation System : SDINS is designed and implemented for low speed walking robot, by modifying Inertial Navigation System which is widely used for rocket, airplane, ship and so on. In addition, thesis proposes the localization of robot with the method of loosely coupled method by using Kalman Filter with INS/GPS integrated system to utilize assumed position and steed data from GPS.

• Proceedings of the KWS Conference
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• v.43
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• pp.213-215
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• 2004

Water jet propulsion system has high efficiency on middle to high speed, and it provides better safety than conventional screw propeller because it has not projected propeller and rudder. So many leisure boat and high-speed ferries use this propulsion system. We developed water-jet propulsion unit for small planning boat, and launched that in the boat, after that we tested water-jet unit in the lake. As a result, we certify heat dissipation at the bearing housing and reverse duct's shape for neutral position are important at the design, and alignment water-jet unit and keel line are important at the launching, and ship's resistance performance and jet's propulsion performance also are needed to consideration.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.3
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• pp.455-460
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• 2008

The flammable gas monitoring system is to be provided in cargo pump rooms of tankers in accordance with the requirements of SOLAS regulations, and flammable gas detectors are to be arranged in a proper position. In this paper, simulation tests and CFD analysis are carried out under the actual ventilation conditions of pump rooms in the ship in service. Based on the results, a new guidelines for an arrangement of flammable gas detectors are suggested.

• Journal of Korean Society for Geospatial Information Science
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• v.2 no.2 s.4
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• pp.125-130
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• 1994

The original concept of GPS is the feature of instantaneous navigation which is the determination of the position of a moving vehicle(ie, a ship, a car, an air craft) by unsmoothed code pseudoranges. The objective of study is compare the efficiency (or time, accuracy) between GPS surveying by using kinematic method and conventional surveying methods in the intersection, and then suggest research materials for actual application.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.867-870
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• 1996

Often an INS has to be aligned in navigation. In these cases it is necessary to obtain some reference information on the state of the aligned INS(Slave) such as its position, its velocity of its angular rate. Usually the reference information is velocity which is supplied by another reference INS. In the alignment state the velocity computed by the reference INS(Master) is compared with that computed by the slave INS and the difference which is indicative of the slave misalignment with respect to the master, is processed by a Kalman filter which estimates misalignment as well as the slave gyro and accelerometer error states. The operation of aligning a slave INS with a master INS comparing quantities computed by both INS is known as transfer alignment. The delivery vehicle performs error these maneuvers enable the TA Kalman filter to separate between the tilt errors and the accelerometer biases which otherwise are unobservable. The basic objective this paper is to study the observability enhancement by ship's maneuvering and matching methods during transfer alignment at sea.

• Journal of the Korean Institute of Navigation
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• v.6 no.1
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• pp.61-72
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• 1982

As it is well-known, in recent years the Kalman filter has been extensively used in the engineering field. The authors tried to apply the extended Kalman filter for optimal estimation of ship's positiion which is fixed by simultaneous visual (or radio) bearings to two known locations. In practical piloting, bearings are generally measured intermittently, so in this case the original Kalman filter can not be applied because of the long sampling time. In this paper, the extended Kalman filter is revised in order to be used in such an unfavorable case, adn the Digital simulation is conducted by using the revised extended Kalman filter under various noise conditiions. Good results have been obtaiend and effectiveness of the proposed filter has been confirmed.