Eigenvalue Analysis for Motion Reponse of a TLP and Tender Semi Considering a Complex Mooring Configuration
Abstract Eigenvalue analysis was carried out for a complex system of multiple floating bodies with various connectors. In this study, multiple floating bodies are a tension leg platform (TLP) and a semisubmersible platform that are connected with hawser and mooring lines. To perform the eigenvalue analysis, mathematical formulation is derived including linear stiffness and added […]
Visibility graph-based path-planning algorithm with quadtree representation
Abstract In recent years, unmanned surface vehicles (USVs) have been widely used in various applications. To fulfill target missions, USVs must be able to plan their path to the destination. Although many path-planning methods have been developed, most are inappropriate for application in complex marine environments. In this study, we propose a novel path-planning algorithm, […]
iSAM2 using CUR matrix decomposition for data compression and analysis
Abstract We introduce a factorization method to increase the calculation speed of incremental smoothing and mapping using Bayes tree (iSAM2), which is used in the back-end stage of simultaneous localization and mapping (SLAM), and to analyse the cause of the associated estimation error. iSAM2 is the method most commonly used to increase the accuracy of […]
Experimental Study on Effect of Density Ratio and Phase Transition During Sloshing Impact in Rectangular Tank
Abstract In this study, experiments are conducted to examine the effect of the density ratio and phase transition on the sloshing impact. In order to create a condition in which phase transition may occur during sloshing impact, a liquid called NOVEC 7000 which has a boiling point of 34 °C is used for the experiment. A […]
Data Mining in Sloshing Experiment Database and Application of Neural Network for Extreme Load Prediction
Abstract Database of the sloshing model test has been mined. More than 540 terabytes experimental data have been accumulated for various cargo holds, vessels, environmental conditions, operational conditions, and experimental conditions. The database was organized, cleaned, and analyzed for the floating units larger than standard size LNG carriers or LNG fueled vessels. The selected target data was […]
Comparative Study on Analysis Methods for Added Resistance of Four Ships in Head and Oblique Waves
Abstract This paper presents a comparative study of wave-induced motion responses and the added resistance of a ship. Four representative types of ships are adopted as test models: LNG carrier, tanker, containership, and bulk carrier. Two experimental techniques—captive and free-running model tests—are conducted under regular head and oblique wave conditions to create benchmark data. Several […]
Experimental Measurement and Numerical Validation of Sloshing Effects on Resistance Increase in Head Waves
Abstract Most sea trials of large merchant ships are carried out with the filling ballast water in cargo, and the trial environment may involve mild waves as well. It causes the ship to undergo a coupling effect between external wave excitation and internal sloshing motion, and an understanding of such coupling is important to analyze the components of the […]
Towing-Tank Measurement of Unsteady Wave Elevation around Two Ships in Head Sea Condition and Comparison with Computational Results
Abstract Many studies on ship wave elevation measurement have been performed focusing on steady waves in calm water and unsteady wave-cut analysis near ships, and a reliable experimental database of unsteady wave elevation with incident waves is not enough for the validation of numerical computations. In this study, a non-contact scheme for capturing the instantaneous […]
Development of Enhanced Two-Time-Scale Model for Simulation of Ship Maneuvering in Ocean Waves
Abstract In this study, a modified two-time-scale model is proposed to overcome the limitations of the existing maneuvering analysis model. To this end, not only wave conditions but also all directions of ship operation velocities are considered in estimating wave drift force and moment. Subsequently, the increment of the drift force and moment induced by […]
Study on Hull Optimization Process Considering Operational Efficiency in Waves
Abstract This study investigates the optimization of the hull form of a tanker, considering the operational efficiency in waves, in accordance with the recent Energy Efficiency Design Index regulation. For this purpose, the total resistance and speed loss of the ship under representative sea conditions were minimized simultaneously. The total resistance was divided into three […]
