• Journal of Navigation and Port Research
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• v.29 no.7
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• pp.603-609
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• 2005

This paper presents the method for developing an optimum hull form with minimum wave resistance using SQP( sequential quadratic programming) as an optimization technique. The wave resistance is evaluated by a Rankine source panel method with non-linear free surface conditions and the ITTC 1957 friction line is used to predict the frictional resistance coefficient. The geometry of the hull surface is represented and modified using NURBS(Non-Uniform Rational B-Spline) surface patches. To verify the validity of the developed program the numerical calculations for Wigley hull and Series 60 Cb=0.6 hull are performed and the results obtained after the numerical calculations are compared with the initial hulls.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.44 no.1
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• pp.68-74
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• 2008

This study is concerned with the development of the basic planing hull form of small fishing boat in 25 knots high speed. A series of model test to determine the optimum performance hull form of actual fishing boat with 10 gross tonnage was carried out for 5 models made available planing hull form in the circulation water channel. Model test was performed with the resistance test to study the hydrodynamic characteristics of model ships and the sinkage and trim measurement to investigate the stability of model ships and also the wave pattern observation to analyze the effectiveness of model ships. As the result, the planing hull form of P-4 with deep V type bow can be derived as the best hull form with good performance especially in ship's resistance efficiency showing less residual resistance and sinkage and trim and the spray effect, etc..

• Journal of Ocean Engineering and Technology
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• v.12 no.3 s.29
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• pp.103-111
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• 1998

This paper describes the initial hull form design process which generate a hull form using a neurofuzzy modeling. Neurofuzzy system is to combine the merits of fuzzy inference system and neural networks. Therefore it has structured knowledge representations as well as adaptive capacities. Initial hull form design stage is the process which generate an adoptable hull form from the limited design information and multi-decidions condidering correlations with design factors. It can be assidted efficiently by neurofuzzy system. This paper suggests two methods of an initial hull form generation using the neurofuzzy modeling and B-spline theory. and examines the usefulness of suggested method through its application examples.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.299-304
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• 2008

Dynamic characteristics of smart hull structure are investigated and active vibration control performance is evaluated. Dynamic model of smart hull structure with surface bonded Macro-fiber Composite (MFC) actuators is established by analytical method. Equations of motion of the host hull structure are derived based on Donnell-Mushtari equilibrium equations for a thin cylindrical shell. A general model for the interaction between hull structure and MFC actuator is included in the dynamic model. Modal analysis is then conducted and mode shapes and corresponding natural frequencies are investigated. After constructing of the optimal control algorithm, active vibration control performance of the proposed system is evaluated. It has been shown that structural vibration can be reduced effectively with proper control input.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.8
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• pp.832-840
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• 2008

Dynamic characteristics of smart hull structure are investigated and active vibration control performance is evaluated. Dynamic model of smart hull structure with surface bonded macro-fiber composite(MFC) actuators is established by analytical method. Equations of motion of the host hull structure are derived based on Donnell-Mushtari equilibrium equations for a thin cylindrical shell. A general model for the interaction between hull structure and MFC actuator is included in the dynamic model. Modal analysis is then conducted and mode shapes and corresponding natural frequencies are investigated. After constructing of the optimal control algorithm, active vibration control performance of the proposed system is evaluated. It has been shown that structural vibration can be reduced effectively with proper control input.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.1
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• pp.123-128
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• 2011

Hull design for a small scale Oceanographic buoy will be introduced in this paper. The hull structure design, the connection methods between all parts will be discussed. We mainly introduce a design process of this buoy hull. We use walls with two layers and a radial bone structure to support the body to increase overall intensity and capacity to resist impact.

• Journal of the Society of Naval Architects of Korea
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• v.34 no.3
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• pp.96-103
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• 1997

This paper presents a mathematical method that represents efficiently high-speed coastal fishing vessel. That is, it represents the numerical hull by using irrational function and hull form characteristic curves, which define a hull form under design conditions. Then it suggests a process that hull form characteristic curves are represented with NURBS and hull form is varied.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.650-655
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• 2006

Dynamic modeling and active vibration control of smart hull structure using Macro Fiber Composite (MFC) actuator is conducted. Finite element modeling is used to obtain equations of motion and boundary effects of smart hull structure. Modal analysis is carried out to investigate the dynamic characteristics of the smart hull structure, and compared to the results of experimental investigation. Negative velocity feedback control algorithm is employed to investigate active damping of hull structure. It is observed that non-resonant vibration of hull structure is suppressed effectively by the MFC actuators.

• YAKHAK HOEJI
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• v.47 no.4
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• pp.212-217
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• 2003

We have carried out the antioxidative activity of nuts species for the development of antioxidant from natural products. From our previous report, EtOAc and n-BuOH extracts of acorn hull and chestnut hull were found to have a strong antioxidative activity in various antioxidant experiment. In the continuous study, we isolated several compounds from EtOAc and n-BuOH extracts of acorn hull and chestnut hull by fractionation using column chromatography. The structures of isolated compounds were identified as catechin, naringenin and ellagic acid on the basis of their spectroscopic properties and by comparison of their physical and spectra data with published value. Antioxidative activities of catechin, naringenin and ellagic acid were measured by DPPH, ferric-thiocyanate and Rancimat method.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.8 s.113
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• pp.840-847
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• 2006

Dynamic modelingand active vibration control of smart hull structure using Macro Fiber Composite (MFC) actuators are conducted. Finite element modeling is used to obtain equations of motion and boundary effects of smart hull structure. Modal analysis is carried out to investigate the dynamic characteristics of the smart hull structure, and compared to the results of experimental investigation. Negative velocity feedback control algorithm is employed to investigate active damping of hull structure. It is observed that non-resonant vibration of hull structure is suppressed effectively by the MFC actuators.