• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.411-415
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• 2007

The reduction of airborne and structure-borne noise of a shipboard pump for a navel ship is very important because the noise levels of the pump must not exceed criteria such as MIL-STD. In this paper, several practical examples of reducing the noise levels are presented. The examples show that the inadequate rotor-balancing and shaft-alignment results in the increase of the structure-borne noise on all lower mounts. It is also found that the unequal loading on mounts can cause the dramatically increasing the noise levels on certain local positions. Since the piping system arrangement such as valve location, flexible joint, and elbow location affects on the noise measurement, care must be taken to minimize the unnecessary noise from the piping system.

• Journal of Integrative Natural Science
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• v.3 no.3
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• pp.138-142
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• 2010

Polystyrene thin films containing Bragg structures have been successfully obtained by the removal of DBR porous silicon films from the DBR structured porous silicon/polystyrene composite film in HF/$H_2O$ mixture solution and by replicating the nano-structures of porous silicon containing Bragg structure. Polystyrene thin films containing Bragg structures displayed unique optical reflection resonances in optical reflection spectrum. This optical reflection band was resulted from the interference of reflection wavelength at Bragg structure of polystyrene thin films. The wavelength of reflection resonances could be modified by the change of Bragg structure of the master. Polystyrene thin films containing Bragg structures were flexible and maintained their optical characteristics upon bending. The Polystyrene thin films replicate the photonic features and the nanostructure of the master.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.04a
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• pp.287-294
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• 1999

The tensegrity structure by prestressed cable, which may have large freedom in scale and form and therefore are received much attention from the view points of their light weight and aesthetics, is a very flexible and geometrically unstable structure because the cable material has little initial rigidity. For the stable self-equilibrated state of the usually very deformable structure, the method to find the optimal initial stress by the shape analysis is proposed in this paper. The proposed procedure is to derive the nonlinear finite element formula of cable and truss members considering geometric nonlinearity and used to modified load incremental method adding to Newton-Raphson method with the proposed condition for optimal initial stress. The result of the shape analysis for the tensegrity structure with the radius of 30m is shown the almost approximated shape to architectural shape and the changed procedure of initial stress

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.167-171
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• 2006

It has been well known that customer' needs have much influence on the structure of supply chains. Uncertainty in customer demands forces companies' supply chains to be very flexible. When a company can not meet customers' changing needs, competitiveness in market places will be jeopardized. To survive in the competitive market places, structure of supply chains should be reconfigurable. In this paper, fractal concept is adopted to handle the reconfigurable issue. In a fractal-based SCM, structure of supply chains can be automatically reconfigured through the dynamic restructuring process with a fractal goal model. Goal in the system is divided into sub-goals, which are represented by a fractal goal model. The fractal goal model is a formal model which can be evaluated, changed, and scaled easily. Thus a well-designed fractal goal model is indispensable for a fractal-based SCM, and enhances the reconfigurability. Fractal structure for reconfigurable SCM is designed and presented. Fractal goal model is applied to SCM and an exemplary case is also briefly illustrated.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.2
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• pp.304-310
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• 2006

A typical honeycomb sandwich panel consists of two thin, high-strength facings bonded to a thick, light-weight core. Each component by itself is relatively weak and flexible, but when it combined in a sandwich panel they produce a structure that is stiff, strong, and lightweight. To prove the suitability the honeycomb sandwich structure with prepreg, the mechanical properties of the skin materials and honeycomb sandwich structure were evaluated with the static strength tests. Accordingly, the honeycomb sandwich structure made by autoclave process is available for a panel on LCD/PDP assembly line.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.10
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• pp.1666-1673
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• 1997

In order to investigate the characteristics of sound-structure interaction plate having a cut-out, we modeled a rectangular cavity and the flexible plate of the cavity. Because the particle velocity of air is the same as that of plate on the plate, we could easily redefine vibration equation using the velocity potential. We calculated the natural frequencies of plate using orthogonal polynomial functions which satisfy the boundary conditions in the Rayleigh-Ritz method. For the change of vibration characteristics, the effect of sound-structure interaction is more dominant than that of cut-out size.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.257-261
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• 2011

The failures of local structure of marine medium-speed diesel engine occurred in durability test. The vibration response of the whole engine was in an acceptance level, but the local structures were broken. ODS test and vibration measurement were carried out in order to investigate the root cause of durability problem. These tests revealed that the root cause of failures was excessive vibration by $4.5^{th}$ resonance between engine body and local structure. The best solution to reduce the vibration response is to change the type of mount. After a rigid mount was replaced by a flexible mount, maximum vibration level dropped to 72%.

• Proceedings of the Korean Biophysical Society Conference
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• 1996.07a
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• pp.29-29
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• 1996

The structure of an antimicrobial peptide buforin II has been studied by $^1$H NMR and CD spectroscopy. Buforin II is flexible and random structure in H$_2$O but the parts of buforin II become helical structure in trifluoroethanol (TFE)/H$_2$O (1:1, v/v) solution. From the restrained molecular dynamics calculation using NMR data, we obtained the possible conformation of buforin II in TFE/H$_2$O solution. (omitted)

• Journal of Ship and Ocean Technology
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• v.3 no.1
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• pp.12-26
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• 1999

A new concept of collision energy absorbing system for ;he New Oil-tankers with Advanced Double Hull Structure(NOAHS and NOAHS II) are presented through the joint-research pro-gran between Inha and Hamburg-Harburg University. A comparative study on col vision resistance of these proposed side structures with standard double hull structure of 310K DWT class VLCC, is carried out. The fatigue investigation of structural detail parts is also included. It contains a comparative fatigue study based on pertinent regulations of Classification Societies.

• Korean Journal of Computational Design and Engineering
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• v.7 no.4
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• pp.269-279
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• 2002

Geometric shape morphing is an interesting geometric operation that interpolates two geometric shapes to generate in-betweens. It is well known that Minkowski operations can be used to test and build collision-free motion paths and to modify shapes in digital image processing. In this paper, we present a new geometric modeling technique to control the morphing on geometric shapes based on Minkowski sum. The basic idea develops from the linear interpolation on two geometric shapes where the traditional algebraic sum is replaced by Minkowski sum. We extend this scheme into a Bezier-like control structure with multiple control shapes, which enables the interactive control over the intermediate shapes during the morphing sequence as in the traditional CAGD curve/surface editing. Moreover, we apply the theory of blossoming to our control structure, whereby our control structure becomes even more flexible and general. In this paper, we present mathematical models of control structure, their properties, and computational issues with examples.