• Journal of the Society of Naval Architects of Korea
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• v.58 no.4
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• pp.234-242
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• 2021

In this study, we introduce the prediction of brake power for low-speed full ships and container carriers using the linear regression and a machine learning approach. The residual resistance coefficient, wake fraction coefficient, and thrust deduction factor are predicted by regression models using the main dimensions of ship and propeller. The brake power of a ship can be calculated by these coefficients according to the 1978 ITTC performance prediction method. The mean absolute error of the predicted power was under 7%. As a result of several validation cases, it was confirmed that the machine learning model showed slightly better results than linear regression.

• Journal of the Society of Naval Architects of Korea
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• v.37 no.3
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• pp.1-10
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• 2000

It is very important to understand the flow characteristics for design of the hull forms with better resistance and propulsive performance. The experimental results explicating the local flow characteristics are also invaluable for validation of the CFD codes for both inviscid and viscous flow calculations. This paper describes the techniques and equipment developed for the measurement of wave pattern on the free surface and local mean velocity fields around the stern of the modern container ship with bow and stern bulbs in KRISO towing tank. The results contained in this paper can provide the valuable information on the flow characteristics of the modern commercial hull form of small block coefficient with high speed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.181-186
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• 2005

A ship runs with various modes of motion due to waves. Among the modes, roll mainly influences on the safety of cargos on the deck of container ship. In order to protect cargo shifting and turning, securing and lashing system are generally installed. In that case, it is necessary that the force and moment at the connection point of containers should be estimated. Therefore we derived mathematical equations to calculate the forces of securing points and lashing wires. Also we calculated those forces and moments about various lashing patterns.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.377-382
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• 2005

A ship runs with various modes of motion due to waves. Among the modes, roll mainly influences on the safety of cargos on the deck of container ship. In order to protect cargo shifting and turning, securing and lashing system are generally installed. In that case, it is necessary that the force and moment at the connection point of containers should be estimated. Therefore we derived mathematical equations to calculate the forces of securing points and lashing wires. Also we calculated those forces and moments about various lashing patterns.

• Journal of the Society of Naval Architects of Korea
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• v.37 no.4
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• pp.1-10
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• 2000

A panel method based on the raised panel approach is developed for the nonlinear ship wave problem of practical hull forms. For the validation of the present numerical scheme. the developed method is first applied to Series 60 hull for which the extensive experimental data are available. As practical applications. the developed method is applied to KRISO 3600 TEU container ship and KRISO 300K VLCC. With the primary emphasis on the nonlinear effects of the global wave pattern generated by the two commercial ships. the calculated wave patterns are compared and verified with the experiments of KRISO. It is found that the calculated results of the present method are quite satisfactory compared with the linear methods like Dawson's approach and Neumann-Kelvin solution.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.3 s.153
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• pp.258-266
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• 2007

CFD calculations are performed for KRISO 3600TEU container ship(KCS) models with different Reynolds numbers. Numerical calculations of the turbulent flows with the free surface around KCS have been carried out at $Re=0.791{\times}106\;and\;Re=1.4{\times}107$ using a standard Fluent package. In both cases, Froude number is fixed with 0.26 and wave elevation is simulated by using the VOF method. The calculated results at $Re=1.4{\times}107\;and\;Re=0.791{\times}106$ are compared with the experiment data of KRISO towing tank test and RIMS CWC test, respectively. Boundary layer thickness and wake field shows Reynolds number differences. There are some changes in wave pattern behind transom stern.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.6
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• pp.415-423
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• 2021

There have been many experimental studies on the manoeuvrability of KRISO Container Ship (KCS). However, the scale ratio of the model ship and the test procedure for each institute are slightly different, so direct comparison for the data is technically difficult to perform. This paper presents the manoeuvrability of the ship with different scale ratios: 1/65.8, 1/42.0, and 1/31.6 in model scale. KRISO conducted Free Running Model Tests (FRMT): 35° turning circle tests and 20/20(10/10) zigzag manoeuvring tests. The test results indicated that advance and tactical diameter in turning circle tests were similar, and overshoot angles in two zigzag manoeuvring tests increased as the model ship size increased. In addition, a basic concept for the FRMT method with an auxiliary X-thrust device was proposed so that the scale effect could be considered in model ship tests.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.12
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• pp.1711-1717
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• 2020

X-ray of up to 9MeV are used for container inspection. X-ray intensity must be maintained stably regardless of changes in time. If dose is not constant, it may affect the image quality, and as a result, may affect the inspection of abnormal cargo. Therefore, to acquire high-quality images, continuous dose monitoring is required. In this study, the ion-chamber based device was developed for monitoring the dose change in high-energy x-ray. And to estimate the performance of signal-processing device change according to the environmental change, the output changing due to the change of temperature and humidity was observed. In addition, verification of the device was performed by measuring the output change. As a result of the measurement, there was no significant difference in performance due to changes in temperature and humidity, and the change in output according to the change in exposure was linear. Therefore, it was found that the developed device is suitable for the dose monitoring of high-energy x-ray.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.12
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• pp.1704-1710
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• 2020

The high-energy X-ray imaging detector used for container inspection uses a thick scintillator to effectively acquire X-rays. X-ray incident on the scintillator is generally up to 9MeV. Therefore, to effectively collect X-ray, it is necessary to use a thick scintillator. To collect the light generated by the reaction between X-ray and scintillator, an optical-sensor must be combined with the scintillator. In this study, a study on the design conditions of the detector using a CdWO4 and a small sensor is described. To calculate the collected light according to the change of the scintillator thickness and the reflectance of surface, MCNP6 and DETECT2000 were used. As a result of calculating, it was confirmed that when the reflectance of the surface was low, it was appropriate to select a scintillator with a thickness of 15 to 20-mm, but as the reflectance increased, it was confirmed that it was appropriate to select a CdWO4 with a thickness of 25 to 30-mm.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.5
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• pp.262-270
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• 2022

The emergence of new concept ships, such as autonomous ships, has drawn much attention on the manoeuvrability of ships because of the safe navigation and operation of ships. Although the manoeuvrability of KRISO Container Ship(KCS) has been frequently reported, there have been few documents of representative manoeuvre cases conducted in various methods by one institute. This paper presents the manoeuvrability of the ship in 1/42.0 model scale by 3 methods: free running model tests, horizontal planar motion mechanism tests, and computational fluid dynamics analysis. KRISO reports KCS manoeuvre data: 35° turning circle tests and 20/20(10/10) zigzag manoeuvring tests. In addition, a simple formula for integrating and comparing manoeuvre indices, Manoeuvrability Comparing Simple Index(MCSI), is proposed.