• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 한국항해항만학회 2022년도 춘계학술대회
• /
• pp.135-136
• /
• 2022

최근 자율운항선박(Maritime Autonomous Surface Ship, MASS)의 개발이 활발히 추진되고 있다. 자율운항선박의 완전한 자동화가 이뤄지기까지 육상센터에서 원격제어(Remote Control)로 선박을 운항하게 된다. 따라서 해기사의 역할을 육상 원격제어자가 수행하게 되며, 원격제어에 요구되는 기술, 교육, 시스템 등 여러 측면으로 이슈가 되고 있다. 아울러, 아직 구체적으로 고려되지 않는 원격제어자의 최적 원격제어 자세에 대한 고려가 필요하다. 제어자세는 업무의 집중도, 사고의 위험성 등에 많은 영향을 줄 수 있다. 그래서 이 연구에서는 현재 일반적으로 항해하는 형태인 서서하는 형태와 앉아서 하는 형태로 구분하여 항해 시 나타나는 해기사의 기술적 행동을 상황인식을 중심으로 고찰하였다. 추후 다양한 기술적 행동 분석 실험을 통해 자세결정을 위한 평가 기법을 제시할 예정이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 한국항해항만학회 2021년도 추계학술대회
• /
• pp.78-80
• /
• 2021

This study is based on Degree of Recognition and AHP surveys for experts, this study investigates changes in the demand of seafarers in response to changes in the shipping industry environment in which Maritime Autonomous Surface Ships(MASS) emerge according to the application of the fourth industrial revolution technology to ships, and it looks into changes in seafarers' skills. It also analyzes and proposes a plan for cultivating seafarers accordingly. As a result of Degree of Recognition and AHP analysis, it is analyzed that a new training system is required because the current training and education system may cover the job competencies of emergency response, caution and danger navigation, general sailing, cargo handling, seaworthiness maintenance, emergency response, and ship maintenance and management, but jobs such as remote control, monitoring diagnosis, device management capability, and big data analysis require competency for unmanned and shore based control.By evaluating the importance of change factors in the duties of seafarers in Maritime Autonomous Surface Ships, this study provides information on seafarers educational institutions response strategies for nurturing seafarers and prioritization of resource allocation, etc. The importance of factors was compared and evaluated to suggest changes in the duties of seafarers and methods of nurturing seafarers according to the introduction of Maritime Autonomous Surface Ships.It is expected that this study is meaningful as it systematically derived the duties and competency factors of seafarers of Maritime Autonomous Surface Ships from a practical point of view and analyzed the perception level of each relevant expert to diagnose expert-level responses to the introduction of Maritime Autonomous Surface Ships.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• 제27권1호
• /
• pp.43-50
• /
• 2017

Acoustic tiles are typically installed on the surface of pressure vessels in submarines to minimize echoes based on the ship's own noise and active sonar. In this study, we studied low frequency active echo reduction techniques to reduce underwater target echo signals. Active control algorithms using tile type projectors and FxLMS logic have been developed and the projectors have been installed in the assumed hull structure. The effectiveness of projectors and control algorithms has been evaluated in time and frequency domain analysis through experiments in the tank.

• Journal of the Korean Society of Marine Environment & Safety
• /
• 제25권6호
• /
• pp.642-648
• /
• 2019

Vessels sail according to the COLREG to prevent a collision. However, it is difficult to apply COLREG under special situation as heavy traffic, at this time personal skills of the operator are required. In this case, traffic control is required through the maritime traffic monitoring system. Therefore, maritime traffic management is globally implemented by VTS. In this system, VTS of icer uses the VTS system to assess risks and recommends possible safety operation to vessels with radio systems. This study considers that the risk analysis method with AI (Artificial Intelligence) technology from the operator's aspect. In addition, the research explains the Maritime Traffic Safety Monitoring System, Including AR (Augmented Reality) technology to increase vessel control efficiency. This system is able to predict hazards and risk priorities, and it leads to sequential elimination of dangerous situations. Especially, the hazard situations can be analyzed from operator's perspective of each vessel instead of the VTS officer's aspect, which is more practical than the conventional method. Furthermore, the result of analysis enables to comprehend quantitative hazardous areas and support recommended routes to avoid a collision. As a result, I firmly believe that the system will support to prevent a collision in complex traffic waters. In particular, it could be adopted as a collision prevention system for Maritime Autonomous Surface Ship, which occupies a significant proportion in Maritime 4th industrial revolution.

• Structural Monitoring and Maintenance
• /
• 제5권2호
• /
• pp.297-311
• /
• 2018

Plate and shell structure is widely applied in engineering, i.e. building roofs, aircraft wings, ship platforms, and satellite solar arrays. Its vibration problem has become increasingly prominent due to the tendency of lightening, upsizing and flexibility. As a new smart material with great actuating force and toughness, macro-fiber composite (MFC) is composed of piezoelectric fiber and epoxy resin basal body, which can be directly pasted onto the surface of plate and shell and is suitable for vibration control. This paper deduces the actuation equation of MFC coupled plate in different boundary conditions, an equivalent finite element modeling method is proposed which uses MFC actuating force as the applied excitation, and on this basis the active control simulation and experiment of MFC over plate and shell structure vibration are accomplished. The results indicate that MFC is able to implement effective control over plate and shell structure vibration in multi-band range. The comparison between experiment and simulation proves that the actuation equation deduced herein, effective and practicable, can be applied into the simulation calculation of MFC vibration control over plate and shell structure.

• Journal of the Korean Society of Propulsion Engineers
• /
• 제3권4호
• /
• pp.75-82
• /
• 1999

Theoretical analysis and performance test of Jet vane type Thrust Vector Control(TVC) were conducted using supersonic cold-flow system. The use of TVC Systems an in particular jet vanes, are currently being researched for use in air launch, ship launch, underwater launch and high altitude maneuvering of tactical missiles and rockets. The necessity to generate control forces to rapidly change the course of the missile is frequently required when traditional, exterior aerodynamic surfaces are unable to produce these forces, when the flow over the control surface is insufficient. This situation can occur at launch, or high angles of attack of the control surfaces. Jet vanes peformed well at all altitudes and environmental conditions, and jet vanes are extremely effective at deflection angles up to as high as $30^{\circ}$, make them ideal for the launch and maneuver applications. In this study, performance test of supersonic cold-flow system and visualization of supersonic jet was conducted, and shape and deflection angle effect of two types of jet vanes are investigated.

• Journal of Navigation and Port Research
• /
• 제38권4호
• /
• pp.335-341
• /
• 2014

Faced with global agenda of greenhouse abatement program including regulations and $CO_2$ emission trading scheme, shipping companies are enforced to a high level of efficiency in fuel consumption. Accordingly shipbuilding companies worldwide are required to develop fuel-efficient ships which otherwise traditionally consume a great amount of fossil fuels. In this dissertation, relevant to the improvement of fuel efficiency for commercial ships, design methodology through the numerical simulations are intensively described. This work consists of derivation of effective hydrodynamic design practice based on the application of longitudinal grooves to effectively improve the pressure distribution around ship hull. The primary objective of the present study is to improve ship resistance performance using longitudinal grooves which originate from long strips on the abdomen of humpback whale. Several groove shapes have been extensively investigated and the proposed shape efficiently controlled the variation of pressure distributions acting on the hull surface.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 한국항해항만학회 2019년도 추계학술대회
• /
• pp.107-108
• /
• 2019

In the past, regional pilot service is provided by individual pilots directly on board each ship, but it will be difficult to provide this type of service in the near future when autonomous vessels are activated. This can be seen as the need for automation and intelligence of pilot service and provision of remote control system. In this paper, we propose a method, system, and service target that can carry out the electronic pilot service through the intelligence aids to navigation for smart port operation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 한국정보통신학회 2015년도 추계학술대회
• /
• pp.433-435
• /
• 2015

Aegis Combat System(ACS) is a shipboard combat system developed by U.S. Navy. Its name, Aegis, came from a shield 'Aegis' in greek mythology, which Zeus gave to his daughter Athena. U.S. Navy uses Aegis ships(ships which mount ACS) as their main surface forces. It is known as one of the greatest anti-air warfare ship in the world by its ability to detect air threats with AN/SPY-1, phased array radar, superior Target management and command and control capabilities of the combat system, and SM series interceptors. After first Aegis cruiser USS Ticonderoga was deployed at 1983, U.S. Navy continuously put effort in developing Aegis Combat Systems and Aegis ships. They also improve old fashion existing ships by modernize them. In this Paper, to deduct a lesson which Korea Navy should benchmark, it is went through that a history of Aegis ships and development of ACS, and also its feature.

• Corrosion Science and Technology
• /
• 제6권5호
• /
• pp.219-226
• /
• 2007

Pre-construction primer (PCP), or shopprimer, have been applied to steel plates to control temporary corrosion during ship fabrication. For surface preparation at ship block stage, in common shipyard practices, welding beads, burnt and rusted areas shall be blasted or power tool cleaned and the contamination such as zinc salt shall be removed with blasting or power tool. Whereas, the sound film of PCP needs not to be removed or roughened as the paint having good compatibility with PCP is used for the first coat. In many cases, however, full blasting or sweep blasting on the sound PCP treated block assemblies was requested. There still has been argument about the legitimacy of this practice, thus, it is critical to evaluate the quality of the coating system applied on the sound PCP retained condition, comparing with the one applied on the full blasted or sweep blasted condition. In this study, two different epoxy systems for water ballast tank were applied on the surfaces with sound PCP condition, full blasted condition, and sweep blasted condition. Coating performances such as durability, anti-corrosion, cathodic disbondment resistance were evaluated. The test results clearly indicated that the sound film of PCP needed not to be removed or roughened as the paint having good compatibility with PCP based on inorganic zinc silicate.