• Journal of Navigation and Port Research
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• v.34 no.8
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• pp.623-628
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• 2010

High speed marine vehicle, such as semi-planing, planing craft have been developed recently. These ships paid attention to the resistance characteristics, especially in high speed region. Model test method is divided to two equipment greatly, first 'Towing tank', second 'C.W.C.'. It is difficult to estimate a resistance characteristics for high speed boat. because these are made for low speed ship. This paper suggests a new model test method and system. This is real sea model test and it's comprised of eight part. Firstly, This method is tested at C.W.C that is possible to using in real sea model tes using low speed boat modelt. And then, Real sea model test and CFD calculation are performed and compared with tow way used high speed boat model. It can be a good way to estimate a performance for high speed boat.

• Journal of Navigation and Port Research
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• v.38 no.6
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• pp.593-600
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• 2014

Information supporting system which is based on real-time prediction of currents to be applicable to the sea trial test of ship is developed. In the system, the spatial distribution of currents at specific time and the trends of variability of currents occurring at specific sites are also given as valuable information for sea trial test of ship. In addition, the system has a capability to connect with a GPS which provides information including speed loss of the ship caused by currents on the way of voyage. With information from the sea trial test, the system is also capable of delivering optimum time and pathways by considering calculated speed loss of ship at specific time and its pathway. Having information described as above, the real-time current prediction system supports and provides functions of not only running the test in an efficient way but also providing valuable information which is encouraged to be used during the test by installing at the ship.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.355-358
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• 2006

An underwater mooing target position tracking system using image tracking system of CPMC is developed to use in a test basin. Generally the performance tests of Autonomous Underwater Vehicles(AUVs) are conducted in the sea. Some efforts to perform the test in a test basin are exist, because the real sea tests need much time and manpower. And also the real sea tests are high cost. There is a restriction to acquire the position of AUVs using sonar sensor system in the test tank, because many sound reflecters are exist in a test basin. In this paper a position tracking system for underwater mooing target developed to break though this restriction. A Tank-test is conducted to examine the performance of the position tracking system.

• Journal of Ocean Engineering and Technology
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• v.23 no.3
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• pp.53-58
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• 2009

A scale model test for ship Infra-Red signature measurements at sea is impossible, because it is sensitive to the environment. Since we can't control the meteorological environment of the real sea, it can't be carried out with the desired maritime environments. Therefore, in the sea, we made measurements of the weather, operating conditions of the ship, and ship IR signatures under given conditions, and then analyzed them. Conversely, we compared the results of the test with a prediction for a given scenario condition. This paper describes the test items, procedures, and measuring instruments of the experiments at sea and the results from basic researches for methods of estimation and analysis of the measured data.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.3
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• pp.229-236
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• 2008

The deep-sea miner is the tracked vehicle system which drives on the deep-seabed and gathers a manganese nodules. The miner is operated by remote control in real-time by the station of surface vessel. So operating S/W is a important part of miner remote operating. At present, the test miner has been designed and manufactured for near-shore sea-test. The test miner consists of mechanical parts, and electric-electronic parts. Because those parts should be controled and monitored remotely, operating S/W for control and monitoring is necessary by all means. In this paper, real-time operating S/W for a control and monitoring of the test miner was designed and developed using PXI, embedded controller and LabVIEW. This real-time operating S/W was developed for an efficient test of test miner in a near seabed area. Moreover, database management system(DBMS) was developed too for the data management of test miner monitoring using MS SQL and LabVIEW.

• Proceedings of the Korea Port Economic Association Conference
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• 2007.10a
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• pp.161-173
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• 2007

This paper considers the problem of determining the cargo flow and the transportation mode in each trade route while satisfying the demand. Especially, the problem incorporates short sea shipping in Korea, which is becoming more important in order to improve efficiency of Logistics. The objective is to minimize the sum of shipping and inland transportation costs. To solve optimally the problem, this paper employs a linear programming model, which is an operations research technique for optimization. The problem is formulated by extending the well-known network design problem by considering capacity at seaport and limitation of total number of vehicles. The model is solved using CPLEX, a commercial linear program software. The test results using a real cargo flow data in Korea show that the model represents closely the real situation.

• Journal of Ocean Engineering and Technology
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• v.21 no.6
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• pp.101-106
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• 2007

In this paper, the authors demonstrate a new idea to take the place of the real pressure vessel test, which should be carried out in a high pressure experiment unit before the real sea trial test. The idea is to make a pressure vessel model as a replica of the real pressure vessel test, which can reduce the cost of making a pressure vessel and large pressure experiment unit. The pressure vessel model was designedbased on linear-elastic, buckling equations and Finite Element Analysis. The manufactured pressure vessel model was investigated and monitored while the pressure test was being conducted. After the test, the result and the validity of the pressure vessel model as a replica of the real pressure vessel test was studied.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.89-90
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• 2008

We present an implementation and it's real-sea test of an underwater acoustic communication system, which allows the system to reduce complexity and increase robustness in time variant underwater environments. For easy adaptation to complicated and time-varying environments of the ocean, all-digital transmitter and receiver systems were implemented. For frame synchronization the CAZAC sequence was used, and QPSK modulation/demodulation method with carrier frequency of 25kHz and a bandwidth of 5kHz were applied to generate 10kbps transmission rate including overhead. To improve transmission quality, we used several techniques and algorithms such as adaptive beamforming, adaptive equalizer, and convolution coding/Viterbi decoding. For the verification of the system performance, measurement of BER has been done in a very shallow water with depth of 20m at JangMok, Geoje. During the experiment, image data were successfully transmitted up to about 9.6km.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.5
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• pp.390-395
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• 2011

The main purpose of ice model basin is to assess and evaluate the performance of the Arctic ships and offshore structures because the full-scale tests in ice covered sea are usually very expensive and difficult. There are various ice conditions, such as level ice, brash ice, pack ice and ice ridge, in the real sea. To estimate their capacities in ice tank accurately, an appropriate model ice sheet and prepared ice conditions copied from actual sea ice conditions are needed. Pack ice is a floating ice that has been driven together into a single mass and a mixture of ice fragments of varying size and age that are squeezed together and cover the sea surface with little or no open water. So Ice-class vessels and Icebreaker are usually operated in pack ice conditions for the long time of her voyage. The most ice model tests include the pack ice test with the change of pack ice concentration. In this paper, the effect of pack ice size and channel breadth in pack ice model test is conducted and analyzed. Also we presented some techniques for the calculation of pack ice concentration in the model test. Finally, we developed a new model test methodology of pack ice condition in square type ice tank.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.2
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• pp.219-224
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• 1998

Recently to achieve the anti-corrossive effect in propeller shafts the coating technique with suit-able coating materials is available instead of bronze-sleeved shafts. In this case the coating mate-rials in service must not be delaminated from the shaft and the crack must not be originated. Thus the various performance and security test for coating materials of propeller shaft must be carried out under the real conditions or more severe circumstance. The most important factors effecting on the funtion of coating materials in propeller shaft are the strain and the environment of sea water. In this paper therefore the maximum possible strain which can be occured in real propeller shaft was calculated based on IACA standard classification rule in order to give the proper level of strain to the test samples in performance test of propeller shaft coating materials.