• Title/Summary/Keyword: ship stability

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A study on the Improvement of control performance of Auto Steering System by Fuzzy Scheme (퍼지기법에 의한 자동조타기의 제어성능개선에 관한 연구)

  • Kang, Chang-Nam
    • Proceedings of the KIEE Conference
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    • 2005.07d
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    • pp.2671-2674
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    • 2005
  • Auto Pilot System is the device for course keeping or course altering to ship's steering system. The purpose of automatic steering system is to keep the ship's course stable with the minimum course and rudder angle. Recently, modem control theories are being used widely in analyzing and designing the ship system. Though P.I.D type auto pilots are widely used in ships, the stability and the adjusting meyhods are not clarified. In this paper the authors proposed auto pilot system with Fuzzy Logic Controller. In the fuzzy control the things that the actual operators of a steering wheel has acquired through their experience can be logically described by the Lingustic Control Rule. The characteristic of the control system were investi gated through the computer simulation results. it was found that the fuzzy logic control was more efficient than the conventional system.

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Design for Safety :Development and Application of a Formalised Methodology

  • Vassalos, Dracos;Oestvik, Ivan;Konovessis, Dimitris
    • Journal of Ship and Ocean Technology
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    • v.4 no.4
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    • pp.1-18
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    • 2000
  • The paper describes a formalisation of a Design for Safety methodology in an integrated envi-ronment, outlines early developments of a software tool, and presents the results of an appli-cation of the methodology to a case study. The approach adopted attempts link safety per-formance prediction through the utilisation of appropriate technical tools, safety assessment deriving from risk-based methodologies and disparate design activities and issues. Black-board systems have been utilised as the platform in the development of the integrated design environment, allowing safety assessment to become an integral part of the design process. Finally, the case study addresses the application of the developed methodology to three dif-ferent arrangements of a conventional passenger Ro-Ro vessel, with the aim to demonstrate the validity of the process and methodology adopted. The findings are presented and dis-cussed, and recommendations given for the way forward.

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Electric Power System Design and Analysis for Drilling Rigs

  • Kim, Chul-Ho;Kim, Yoon-Sik;Jung, Hyun-Woo;Ryu, Seung-Nam;Yoon, Kyoung-Kuk
    • Journal of Advanced Marine Engineering and Technology
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    • v.36 no.7
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    • pp.942-947
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    • 2012
  • As electricity has been used in ship's propulsion, it is necessary to increase the system voltage and current for the electrical distribution system. So it is required to improve the system safety and efficiency, the power stability, the efficiency of the generation through various analysis of ship's electric power system. In this paper, the electrical service reliability of the power distribution system of semi submersible drilling rigs has been analysed and discussed using ETAP.

A Study on the Ultimate Strength of a Ship's Plate in used Arc-Length Method (호장증분법을 이용한 선체판의 최종강도에 관한 연구)

  • 고재용;박주신
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.04a
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    • pp.496-503
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    • 2003
  • Recently, the buckling is easy to happen a thin plate and High Tensile Steel is used at the structure so that it is wide. Especially, the buckling is becoming important design criteria in the ship structure to use especially the High Tensile Steel. Consequently, it is important that we grasp the conduct after the buckling behaviour accurately at the stability of the body of ship structure. In this study, examined closely about conduct and secondary buckling after initial buckling of thin plate structure which receive compressive load according to various kinds aspect ratio under simply supported condition that make by buckling formula in each payment in advance rule to place which is representative construction of hull. Analysis method is F.E.M by ANSYS and complicated nonlinear behaviour to analyze such as secondary buckling.

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Application of the Weak-Scatterer Hypothesis to the Wave-Body Interaction Problems

  • Kim, Yong-hwan;Sclavounos, Paul-D.
    • Journal of Ship and Ocean Technology
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    • v.4 no.2
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    • pp.1-12
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    • 2000
  • The present study concentrates on the weak-scatterer hypothesis for the nonlinear wave-body interaction problems. In this method, the free surface boundary conditions are linearized on the incoming wave profile and the exact body motion is applied. The considered problems are the diffraction problem near a circular cylinder and the ship response in oblique waves. The numerical method of solution is a Rankine panel method. The Rankine panel method of this study adopts the higher-order B spline basis function for the approximation of physical variables. A modified Euler scheme is applied for the time stepping, which has neutral stability. The computational result shows some nonlinear behaviors of disturbance waves and wave forces. Moreover, the ship response shows very close results to experimental data.

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Development of Design Technology for Safety Enhancement of Damaged Ship (손상 선박의 안전성 향상 설계 기술 개발)

  • Lee, Soon-Sup;Lee, Dong-Kon;Kim, Ki-Sup
    • Journal of the Society of Naval Architects of Korea
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    • v.46 no.1
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    • pp.69-77
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    • 2009
  • Loss of human lives and properties including environmental damage due to large scale accidents requires change of our perception to marine safety. IMO is trying to re-establish overall marine safety system through long term plan such as GBS. Along this line, current regulation based safety evaluation is in process of changing into performance based methods, and for this transition, simulation based safety evaluation during design stage considering damage is highly necessary. In this paper, first, damage scenario is developed from IMO regulations and accident case studies. Then an integrated and simulation based safety evaluation prototype system considering both damage stability and structural safety is developed for the use during ship design process.

A Study on the Deflection Mode of a Ship's Plate according to the Arc-Length Method (호장증분법에 의한 선체판의 처짐모드에 관한 연구)

  • 고재용;박주신;이돈출;박성현
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.732-737
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    • 2003
  • Recently, the buckling is easy to happen a thin plate and High Tensile Steel is used at the structure so that it is wide. Especially, the buckling is becoming important design criteria in the ship structure to use especially the High Tensile Steel. Consequently, it is important that we grasp the conduct after the buckling behaviour accurately at the stability of the body of ship structure. In this study, examined closely about conduct and secondary buckling after initial buckling of thin plate structure which receive compressive load according to various kinds aspect ratio under simply supported condition that make by buckling formula in each payment in advance rule to place which is representative construction of hull. Analysis method is F.E.M by ANSYS and complicated nonlinear behaviour to analyze such as secondary buckling.

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A Study on the Stability of a Low Freeboard Coastwise Tanker Capsized in Turning (2) - Experimental Examination of the Outward Heel Moment Induced by Flooding of Seawater onto the Deck - (선회중 전복한 저건현 내항 탱커의 복원성에 관한 연구 (2) - 갑판상 해수 침입이 경사 모멘트에 미치는 영향에 대한 실험적 조사 -)

  • 김철승;공길영;김순갑
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2002.03a
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    • pp.145-153
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    • 2002
  • A coastwise chemical tanker sailing at full speed has capsized in calm water and whole turing. In the precious paper, we investigated reasons of the accident by demonstrating the proper correction for the free surface effect of the liquid cargo and the bow-sinkage effect. In this paper, we also carry out model experiments of a transverse pressure under the seawater and an outward heel moment according to the heel angle and rudder angle, on the basis of radius of turning circle, ship's speed and drift angle of model ship occurring in turning. It is also shown that the flooding of seawater onto the deck occurring in turning generated a significant outward heel moment and the vertical distance between the center of gravity of the ship and the renter of lateral water drag.

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A study on the Improvement of control performance of Auto Steering System (자동조타기의 제어성능개선에 관한 연구)

  • Kang, Chang-Nam
    • Proceedings of the KIEE Conference
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    • 2005.10c
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    • pp.114-117
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    • 2005
  • Auto Steering System is the device for course keeping or course altering to ship's steering system. The Purpose of automatic steering system is to keep the ship's course stable with the minimum course and rudder angle. Recently, modern control theories are being used widely in analyzing and designing the ship system. Though P.D type auto pilots are widely used in ships, the stability and the adjusting methods are not clarified. In this paper the authors proposed auto steering system with Fuzzy Logic Controller. In the fuzzy control the things that the actual operators of a steering wheel has acquired through their experience can be logically described by the Lingustic Control Rule. The characteristic of the control system were investigated through the computer simulation results. it was found that the fuzzy logic control was more efficient than the conventional system.

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Efficient Multicasting Mechanism for Mobile Computing Environment (영상추적 Video Tracking 개발과 시스템 Integration)

  • Lee, WonBu;Chang, Chulsoon;Park, Soohong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.05a
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    • pp.623-626
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    • 2009
  • New ship technology and trapping equipment must be implemented into ship sailing which is currently used nowadays. The day/night camera stability, user interface, track, and remote control system of Jim structure for all over the world should be competitive in the global market. The development equipment sales are losing its competitiveness edge of the existing sailing ship communications equipment due to supply to the aging of the entire system and integration of the development especially for foreign equipment competitor.

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