• International Journal of Internet, Broadcasting and Communication
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• v.8 no.1
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• pp.53-63
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• 2016

This paper applies WiMedia UWB network into a wireless ship area network (WSAN) so as to support high-quality multimedia services on board and reliable instrument control information as well, since the need for mixed high-quality video traffic and shipboard control data traffic is essential for a high-cost valued digital ship. Thus, in this paper, prioritized contention access (PCA) and distributed reservation protocol (DRP) based on WiMedia UWB (ECMA-368) MAC protocols are combined and proposed to such mixed traffic environment, by varying the portions of superframe according to traffic type. It is shown that the proposed WiMedia UWB MAC protocol can provide reliable mixed video and shipboard control data traffic as well.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.2
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• pp.155-162
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• 2012

This work describes identification of essential considerations when we develop OMS/MP for the shipboard weapon systems. It is compulsory to develop OMS/MP which describes quantity of what mode to have and how often to operate. In this point of view, relationships between OMS/MP and shipboard weapon systems are analyzed. From the analysis, considerations of OMS/MP development for the weapon systems are presented.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.1
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• pp.67-73
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• 2002

This paper presents the development of development of stabilization and tracking algorithms for a shipboard satellite antenna system. In order to stabilize the satellite antenna system designed in the previous work, a model for each control axis is derived and its parameters are estimated using a genetic algorithm, and the state feedback controller is designed based on the linearized model. Then a tracking algorithm is derived to overcome some drawbacks of the step tracking. The proposed algorithm searches for the best position using gradient-based formulae and signal intensities measured according to a search pattern. The effectiveness of both the stabilization and tracking algorithms is demonstrated through experiment using real-world data.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.1035-1040
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• 2005

This paper deals with the design rule and performance results of the surge protective devices (SPDs) for low-voltage mains on shipboard. The proposed SPDs consists of a metal oxide varistors (MOV) and a L-C filter to improve noise-elimination performance. Three kinds of SPDs are fabricated and tested by using a combination surge generator which produce the standard impulse current of 8/20${\mu}s$ 2.1kA. As a results, the proposed SPDs with series L-C filter have more excellent transient blocking and noise reduction performance than the conventional ones.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.1161-1165
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• 2005

Due to the miniaturization of electrical components and assembles on signal circuits, transient overvoltages caused by switching operation or lightning surges have become more interesting concern to the field of electrical engineering. In this paper, the development of surge protective devices(SPDs) that can protect sensitive signal device on shipboard from overvoltages are described. Two kinds of SPDs are designed and tested by using a combination surge generator which can produce the standard impulse current of 8/20${\mu}s$ 2.1kA according to the IEC 61000-4-5 standard. From the simulation and experimental results, it is confirmed that the proposed SPDs have an enough protection performance with a low insertion loss and a low clamping voltage.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.2
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• pp.114-120
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• 2012

Recently, integrated electric propulsion system has been vigorously adopted into naval vessels. To enhance effectiveness and efficiency of power management in these propulsion systems, this paper investigates necessity of energy storage devices and their operation strategies. By introducing the energy storage devices, engine can operate at higher efficiency point and accordingly costs for fuel and maintenance are significantly reduced. In addition, transient performance can also be improved with support of the devices and it leads to stable operation of shipboard power bus. To validate the proposal of this paper, computer simulation has been conducted with real load data of existing electric propulsion system.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.3
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• pp.320-326
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• 2009

The mechanical impedance and stiffness of the foundation of shipboard equipments and hulls supported by anti-vibration mount are very important so that the anti-vibration mount can accomplish its performance effectively. But, it is frequently argued how much stiffness and mechanical impedance are necessary for those foundations and hulls. In this research, it is discussed by evaluating the dynamic stiffness of the commercial anti-vibration mounts used in a naval vessel. Consequently, in this research, the minimum level of the mechanical impedance and stiffness of the foundation of shipboard equipments and hulls are suggested considering the dynamic stiffness of the mount which varies as frequency.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.519-524
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• 2011

The aim of this study is to develop an automated program for noise prediction in shipboard compartments, for this purpose of calculating noise levels accurately and quickly. The program calculates sound power level at HVAC components based on the empirical method suggested by NEBB and utilizing the manufacturer's test data. The program developed uses the GUI functions to help in efficient modeling and calculation. To verify the reliability of developed program, the predicted data was compared with the measured data in shipboard compartments. As a result, the average difference between predicted and measured data is ${\pm}3dB$.

• Journal of the Korean Society of Marine Environment & Safety
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• v.1 no.2
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• pp.93-105
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• 1995

This study is concerned with the efficient improvement in the shipboard training of trainees for the marine officers in the future. The shopboard training course is given much weight in the curriculum of the seamanship education for the characteristics of that. In spite of various earlier studies to improve shipboard training system, we don't have desirable one until now on this problem based upon practical and empirical analysis. It seems a matter of urgency should be settled to improve the training environment-training facilities and equipment including simulator education - for the efficient pratice off-shore during training vessels in port. And it is also desired to regulate downward the credit system needed to graduate that trainees should be immersed in their practice without regard to their school records if passed the course during the training period.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.1
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• pp.41-55
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• 2015

This study is proposed a new hybrid mount having a moving-magnet type electromagnetic actuator to reduce the vibration transmitted from naval shipboard equipment to the structure of the ship's hull. Optimal design specifications are determined through experimental analysis. The detailed design of the hybrid mount is determined through several design steps with electromagnetic numerical analysis using Maxwell Software(S/W). The hybrid mount that combines a rubber mount and an electromagnetic actuator has a fail-safe function for shock resistance. The mount is fabricated and tested using a universal testing machine to evaluate the design specifications. Finally, numerical simulation of the hybrid mount is performed to confirm control performance and applicability.