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International Journal of Ocean System Engineering

Korean Society of Ocean Engineers

  • Quarterly
  • /
  • 2233-6478(pISSN)
  • /
  • 2233-7059(eISSN)

Domain

  • Construction/Transportation ＞ Maritime Safety/Transportation Technology
  • Construction/Transportation ＞ Water Engineering System

Aim & Scope

International Journal of Ocean System Engineering, IJOSE, provides a medium for the publication of original research and development technology in marine/material science and engineering which include: Ocean Engineering; Coastal Engineering; Naval Architecture; Offshore Technology; Frontier Energy Resources Technology; Marine Renewable Energy; Underwater Vehicles and Robotics; Underwater Acoustics and Sonar Technology; Underwater Observation Systems; Underwater Communication and Technology; Marine Equipments; Remote Sensing of Air/Ocean Surface; Ocean Mining; Offshore Mechanics; Marine Hydrodynamics and CFD; Sloshing Dynamics and Design; Vortex-induced Vibration; Cable, Mooring, Buoy Technology; Fluid-Structure Interaction; Hydroelasticity; Risk and Limit State Design and Assessment; Ship Maneuvering; Seakeeping and Control Systems; Ship Resistance and Propulsion; Port and Waterfront Design and Engineering; Geotechnology; Satellite Observation; Shore Protection; Beach Nourishment; Sediment Transport; Mechanics; Safety and Reliability; Subsea; Pipelines; Risers and Positioning; High-Performance Materials; Nano-technologies for Clean Energy; Friction Stir Welding for Oil and Gas; Arctic Materials; Arctic Science and Technology; Advanced Ship Technology; Naval and Offshore Structures and Technology; and Oceanography.

KSCI

Volume 3 Issue 1

  1. Park, Dong-Woo;Choi, Hee-Jong 1
    https://doi.org/10.5574/IJOSE.2013.3.1.001 PDF KSCI
    A design procedure for a ship with minimum resistance had been developed using a numerical optimization method called SQP (Sequential Quadratic Programming) combined with computational fluid dynamics (CFD) technique. The frictional resistance coefficient was estimated by the ITTC 1957 model-ship correlation line formula and the wave-making resistance coefficient was evaluated by the potential-flow panel method with the nonlinear free surface boundary conditions. The geometry of the hull surface was represented and modified by B-spline surface modeling technique during the optimization process. The Series 60 ($C_B$=0.60) hull was selected as a parent hull to obtain an optimized hull that produces minimum resistance. The models of the parent and optimized hull forms were tested at calm water condition in order to demonstrate the validity of the proposed methodolgy.
  2. Yoon, Hyeon Kyu;Lee, Gyeong Joong 10
    https://doi.org/10.5574/IJOSE.2013.3.1.010 PDF KSCI
    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.
  3. Loc, Mai Ba;Choi, Hyeung-Sik;Kim, Joon-Young;Kim, Yong-Hwan;Murakami, Ri-Ichi 16
    https://doi.org/10.5574/IJOSE.2013.3.1.016 PDF KSCI
    This paper presents a design of fuzzy PD depth controller for the autonomous underwater vehicle entitled KAUV-1. The vehicle is shaped like a torpedo with light weight and small size and used for marine exploration and monitoring. The KAUV-1 has a unique ducted propeller located at aft end with yawing actuation acting as a rudder. For depth control, the KAUV-1 uses a mass shifter mechanism to change its center of gravity, consequently, can control pitch angle and depth of the vehicle. A design of classical PD depth controller for the KAUV-1 was presented and analyzed. However, it has inherent drawback of gains, which is their values are fixed. Meanwhile, in different operation modes, vehicle dynamics might have different effects on the behavior of the vehicle. In this reason, control gains need to be appropriately changed according to vehicle operating states for better performance. This paper presents a self-tuning gain for depth controller using the fuzzy logic method which is based on the classical PD controller. The self-tuning gains are outputs of fuzzy logic blocks. The performance of the self-tuning gain controller is simulated using Matlab/Simulink and is compared with that of the classical PD controller.
  4. Lee, Keunhwa;Park, Sanghyun;Kim, Kookhyun;Seong, Woojae 22
    https://doi.org/10.5574/IJOSE.2013.3.1.022 PDF KSCI
    A heuristic physical theory of diffraction (PTD) for an acoustic impedance wedge is proposed. This method is based on Ufimtsev's three-dimensional PTD, which is derived for an acoustic soft or hard wedge. We modify the original PTD according to the process of physical optics (or the Kirchhoff approximation) to obtain a 3D heuristic diffraction model for an impedance wedge. In principle, our result is equivalent to Luebbers' model presented in electromagnetism. Moreover, our approach provides a useful insight into the theoretical basis of the existing heuristic diffraction methods. The derived heuristic PTD is applied to an arbitrary impedance polygon, and a simple PTD formula is derived as a supplement to the physical optics formula.
  5. Moon, Kyung-Man;Takeo, Oki;Won, Jong-Pil;Park, Dong-Hyun;Kim, Yun-Hae 33
    https://doi.org/10.5574/IJOSE.2013.3.1.033 PDF KSCI
    Reinforced concrete structures have been increasingly widely used in numerous industrial fields. These structures are often exposed to severely corrosive environments such as seawater, contaminated water, acid rain, and the seashore. Thus, the corrosion problems that occur with the steel bars embedded in concrete are very important from the safety and economic points of view. In this study, the effects of the cover thickness on the corrosion properties of reinforced steel bars embedded in multiple mortar test specimens immersed in seawater for 5 years were investigated using electrochemical methods such as the corrosion potentials, polarization curves, cyclic voltammograms, galvanostat, and potentiostat. The corrosion potentials shifted in the noble direction, and the value of the AC impedance also exhibited a higher value with increasing cover thickness. Furthermore, the polarization resistance increased with increasing cover thickness, which means that the oxide film that is deposited on the surface of a steel bar surrounded by alkali environment exhibits better corrosion resistance because the water, chloride ions and dissolved oxygen have difficulty penerating to the surface of the steel bar with increasing cover thickness. Consequently, it is considered that the corrosion resistance of reinforced steel can be improved by increasing the cover thickness. However, the corrosion resistance values of a steel bar estimated by measuring the corrosion potential, impedance and polarization resistance were not in good agreement with its corrosion resistance obtained by polarization curves.
  6. Kim, Yun-Hae;Ha, Jin-Cheol;Lee, Jin-Woo;Park, Jun-Mu;Han, Joong-Won;Choi, Byung-Keun;Moon, Kyung-Man;Nisitani, Hironobu 38
    https://doi.org/10.5574/IJOSE.2013.3.1.038 PDF KSCI
    Wind turbine generator is, recently, becoming bigger and bigger. So, in order to produce large amounts of electricity generation, we have to consider the length and thickness of the blade. We investigated the skills of processing for making the super thickness laminate through development fabrication process for high speed curing composite heating table.
  7. Kim, Kihun;Jang, In-Sung 44
    https://doi.org/10.5574/IJOSE.2013.3.1.044 PDF KSCI
    This paper describes the design and implementation of a practical underwater positioning system, which is applicable for shallow water depth conditions. In this paper, two strategies are used to enhance the navigation performance. First, a low-cost acoustic-ranging-based precise navigation solution for shallow water is designed. Then, the outlier rejection algorithm is introduced by designing a velocity gate. The acoustic-ranging-based navigation is implemented by modifying the long base line solution. To enhance the tracking precision, the outlier rejection algorithm is introduced. The performance of the developed approach is evaluated using experiments. The results demonstrate that precise shallow water depth navigation can be implemented using the suggested approaches.