• International Journal of Naval Architecture and Ocean Engineering
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• v.5 no.2
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• pp.313-323
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• 2013

Offshore floating structures have so-called moonpool in the centre area for the purpose of drilling, installation of subsea structures, recovery of Remotely-Operated Vehicle (ROV) and divers. However, this vertical opening has an effect on the operating performance of floating offshore structure in the vicinity of moonpool resonance frequency; piston mode and sloshing mode. Experimental study based on model test was carried out. Moonpool resonance of floating offshore structure on fixed condition and motion free condition were investigated. And, the effect of cofferdam which is representative inner structure inside moonpool was examined. Model test results showed that Molin's theoretical formula can predict moonpool resonance on fixed condition quite accurately. However, motion free condition has higher resonance frequency when it is compared with that of motion fixed. The installation of cofferdam moves resonance frequency to higher region and also generates secondary resonance at lower frequency. Furthermore, it was found that cofferdam was the cause of generating waves in the longitudinal direction when the vessel was in beam sea.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.204-209
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• 2004

Recently, the various performances of vehicle are rapidly improved. Therefore tire noise is recognized as important noise source because vehicle noise is considerably reduced. This study is performed for the control of the cavity resonance noise that is structure-borne noise, due to fluid(air)-structure interaction. For this investigation, FRF analysis has been carried out using FEM and we found an important factor affecting cavity resonance. The effect of this factor is confirmed by objective noise test. We confirmed that the result of FRF analysis and objective noise test is that the structure control of tire sidewall can reduce cavity resonance noise due to fluid-structure interaction

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.596-599
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• 2008

Traditionally, tire made a role of function, which is supporting vehicle load, making brake, transferring traction, etc. But tire is a part of vehicle design, nowadays. In accordance with this market trend, customers need a wide tread design tire (i.e. low series tire). Generally low Series Tire means stiffer than general tire. That brings out increasing road noise. (Especially tire cavity resonance noise) Tire noise is divided in structure home noise and air borne noise. Tire cavity resonance noise (structure home noise) come from vibration between tire and vehicle. In the study, we investigated that tire cavity resonance noise is affected by stiffness of tread and sidewall.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.457-462
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• 2009

In a high speed train, aluminium extruded panel is widely used in floor, side wall and roof structures for high bending stiffness and weight reduction. However, with some inevitable reasons, aluminium extruded panel shows inferior sound insulation performance compared with the flat panel having same weight. Especially, occurrence of local resonance modes in the particular frequency band, is one of the main reason in the deterioration of the sound insulation performance. Local resonance modes are generated in the structure which consists of periodic unit structure, such as the aluminium extruded panel. The local resonance frequency is determined by the specification of the unit structure. In this study, we predict the local resonance frequency band on the aluminium extruded panel used for the high speed train, and investigate how the design modification in the unit structure influences the local resonance frequency band and panel bending stiffness. The purpose of the study is to provide the design information for the effective unit structure in order to improve the sound insulation performance of the aluminium extruded panel.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.309-313
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• 2009

A micromechanical resonance sensor detects the resonance frequency shift due to mass or adsorption induced surface stress change during molecular adsorption or interaction on its surface. The resonance sensor is surrounded by gas or liquid solution during operation. To study the resonance shift phenomena depending on its surrounding environment, fluid-structure interaction of the resonance sensor has been analyzed for the different fluid environment and boundary conditions using finite element analysis.

• Proceedings of the Korean Magnetic Resonance Society Conference
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• 1999.06a
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• pp.26-26
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• 1999

• Journal of the Korean Magnetic Resonance Society
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• v.12 no.2
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• pp.65-73
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• 2008

HP1298 (Swiss-Prot ID ; P65108) is an 72-residue protein from Helicobacter pylori strain 26695. The function of HP1298 was identified as Translation initiation factor IF-l based on sequence homology, and HP1298 is included in IF-l family. Here, we report the sequence-specific backbone resonance assignments of HP1298. About 97% of all the $^{1}HN$, $^{15}N$, $^{13}C{\alpha}$, $^{13}C{\beta}$, and $^{13}CO$ resonances could be assigned unambiguously. We could predict the secondary structure of HP1298, by analyzing the deviation of the $^{13}C{\alpha}$ and $^{13}C{\beta}$ shemical shifts from their respective random coil values. Secondary structure prediction shows that HP1298 consists of six $\beta$-strands. This study is a prerequisite for determining the solution structure of HP1298 and investigating the structure-function relationship of HP1298. Assigned chemical shift can be used for the study on interaction between HP1298 and other Helicobacter pylori proteins.

• BMB Reports
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• v.38 no.5
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• pp.591-594
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• 2005

One of the small proteins from Helicobacter pylori, HP1242, was investigated by the solution nuclear magnetic resonance (NMR) spectroscopy. HP1242 is known as a 76-residue conserved hypothetical protein and its function cannot be identified based on sequence homology. Here, the results of the backbone $^1H$, $^{15}N$, and $^{13}C$ resonance assignments of the HP1242 are reported using double- and triple-resonance techniques. About 95% of all of the $^1HN$, $^{15}N$, $^{13}CO$, $^{13}C{\alpha}$, and $^{13}C{\beta}$ resonances that cover 75 non- Proline residues of the 76 residues are clarified through sequential- and specific- assignments. In addition, three helical regions were clearly identified on the basis of the resonance assignments.

• Journal of the Korean Magnetic Resonance Society
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• v.1 no.1
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• pp.21-29
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• 1997

Three typical solvent suppression methods employed for measuring the NOE data that are used for structure determination of polypeptides by modeling were discussed and compared with one another. In the experiments with several peptides composed of 10 to 65 amino acids the presaturation method was found to give severely distorted signal intensities of exchangeable protons, thus making the results based on this method much less reliable.

• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.151-160
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• 2008

In this paper, the analysis results of synthetic resonance characteristics are described for the electrohydraulic thrust vector control actuation system. The synthetic resonance is induced by integration of position servo actuation system on the flexible launch vehicle mounting structure. The new resonance mode is synthesized due to composition of hydraulic resonance for electrohydraulic position servo system with inertia load condition and structural resonance for flexible mounting structure. This synthetic resonance can make stability of control system worse by feedback and amplification of control system. The exact nonlinear analysis model of this phenomenon is developed to predict and design a control algorithm for improvement characteristics. The DPF (Dynamic Pressure Feedback) control algorithm has been designed and has excellent resonance suppression capability.