• 한국소음진동공학회논문집
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• 제19권12호
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• pp.1329-1337
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• 2009

Because the tonal sound of the underwater noise in a naval vessel can be identified from the sub-marine of the enemy, it should be reduced sufficiently. This kind of the noise usually comes from the structure-borne noise of the onboard machine and transfers to the sea through the hull of the ship. The vibration at the high frequency can be reduced sufficiently with damping material. In this paper, the damping coefficient of the steel plate with damping sheet is evaluated by experiment. Using these evaluated properties, the numerical analysis is performed in order to evaluate how much vibration of the generator can be reduced applying damping sheet on the encloser and base of it.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.102-107
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• 2012

In this study, the design procedure of hybrid active mount by an electro-magnetic actuator is proposed to reduce the transmitted force from naval shipboard equipment to ship hull structure. The hybrid type mount which is composed of a passive rubber element and an electro-magnetic actuator is introduced and, through the vibration measurement for the objective pump system, the required force of the actuator is computed and discussed in detail. The initial designs were supposed for three types, one is moving coil type actuator and the others are moving permanent magnet type actuators. Based on the initial design concept, the final designs considering shock resistance and interference with mover and stator are proposed and examined.

• 대한조선학회지
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• 제10권1호
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• pp.1-14
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• 1973

In the Department of Naval Architecture, Seoul National University, the development of computer programs for the computer-aided ship design sponsored by the Ministry of Science and Technology has been begun. The project is to be accomplished as a four-year plan, and the results of the works of the first year, preliminary design of dry-cargo ships based on an optimization technique and some fundamental calculations accompanied with the basic design of ships such as calculations of displacement, hydrostatic characteristics of hull forms, stability, floodable length, load line and longitudinal section modulus, are given in the Report R-72-9[9] published by the sopnsor for the public interests. In this paper, the philosophy and methodological principles with which the preliminary design program given in Appendix II was developed are summerized.

• 대한조선학회지
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• 제24권1호
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• pp.9-16
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• 1987

The second-order steady horizontal force and vertical moment are derived for a freely-floating body in water of finite depth. Momentum relations are used in terms of the Kochin function in the fluid region far from the body. The general results look very similar to those for deep water. The water depth is formally reflected in terms of the ratio between the phase and group velocities of incident waves. Computations are made for a Series 60 hull($C_B=0.6$) and are compared with the corresponding results of deep water. It is shown that the vertical drift moment for slender ships becomes completely free from water depth when the wave-ship length ratio is taken as parameter.

• 대한조선학회 특별논문집
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• 대한조선학회 2011년도 특별논문집
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• pp.90-94
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• 2011

Longitudinal shell member that arranged block unit on 3D-curved surface is performed manual working by designer considering spacing of division characteristic, location and twisting at geometrical 3-dimensional form. Shell expansion drawing that drawn by initial design and shell landing work performed by hull production design have overlap of design work in terms of arrangement of shell longitudinal member. In this study, eliminate design overlap on shell member arrangement that is one of ship longitudinal member. Develop shell member optimization and auto arrangement system.

• International Journal of Naval Architecture and Ocean Engineering
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• 제7권1호
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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.

• 대한조선학회지
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• 제25권3호
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• pp.19-25
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• 1988

The three-dimensional boundary value problem for the unsteady motion of a ship which is translating and oscillating on the free surface of a deep water formulated. Under the assumption that the forward speed is small and order of $\varepsilon$, all formulations are made up to the first order of $\varepsilon$. For the numerical calculation, the three-dimensional source distribution method is applied, and the triangular elements are used to represent the hull surface. The results for the added mass and the damping coefficient for Series 60, $C_B=0.7$ at Fn=0 and Fn=0.2 shows good agreements with those of Inglis, Chang, and Inglis and Price.

• Journal of Ship and Ocean Technology
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• 제9권2호
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• pp.1-10
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• 2005

A light-weight cantilever type towing carriage was devised and installed in the towing tank at Seoul National University. Wireless measurement devices were also provided for appropriate data acquisition during high-speed towing tests. With the new carriage system, a series of model tests were performed to investigate the hydrodynamic characteristics of the racing boat in the towing tank and the resistance test results had sufficient accuracy so that they could be used in the development of a high speed planning hull.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 춘계학술대회 논문집
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• pp.144-149
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• 2001

A study for the structural strength analysis on the doubler plate subjected to the axial, biaxial in-plane compression and shear load has been performed through the systematic evaluation process. In order to estimate the proper static strength of doubler plate, non-linear elasto-plastic analysis is introduced. Gap element modeling for contact effect between main plate and doubler is prepared and nonlinear analysis procedures are illustrated based on MSC/N4W . In addition, some design guides are suggested through the consideration of several important effects such as corrosion of main plate, doubler width, doubler length and doubler thickness. Finally theses results are compared with developed design formula based on the buckling strength and general trends and design guides according to the variation of design parameters are discussed.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.40-44
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• 2004

A fact that limits a company's ability to achieve more of its goal is referred to as a 'constraint' shipbuilding industries need to identify and manage constraints. The theory of constraints is evolved out of the problems of bottleneck formation. This happens and is conserved for the formulation if various real time problems for arriving standard uniquely addressed problems If, for example, the goal of a shipbuilding industry is to make money now and in the future, it is suggested that TOC will enable th mangers of the company to do so. TOC, focuses the organization scare resources on improving the performance of the true constraints, and therefore the bottom line of the organization. An attempt is made for the implantation of the theory into real world shipyard decision support mechanism.