• Polymer(Korea)
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• v.39 no.1
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• pp.107-113
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• 2015

The effects of silica-silane in CIIR vibration isolation compound were investigated regarding mechanical and dynamic properties. Addition of silica-silane in the compound resulted in higher tear resistance strength and elongation at break than the control, which was increased by 13% and 14%, respectively. Other values such as tensile strength and hardness did not show significant changes. Viscoelastic property results supported that the improvement of tear resistance strength and elongation at break resulted from the formation of 3-dimensional network structure between silica and CIIR. The mechanism of the tear resistance strength and elongation at break improvement was discussed.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.2 s.54
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• pp.19-26
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• 2007

This paper presents the results of experimental studies of the mechanical characteristics of the Coil Spring and Viscous Damper system. The Coil Spring and Viscous Damper systems were selected for the isolation of Emergency Diesel Generator (EDG) which is located in Nuclear Power Plant (NPP). The Coil Spring and Viscous Damper systems were developed for the operating vibration isolation and seismic isolation for scaled Model EDG System. The damping properties of the viscous damper changes as the variation of velocity. Through this research nonlinear damping characteristics and the effective stiffness of coil spring and viscous damper system were evaluated.

• Natural Product Sciences
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• v.16 no.4
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• pp.228-232
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• 2010

Bioactivity-guided fractionation using on-line HPLC biochemical detection system on $CHCl_3$-soluble fraction of Lycoris radiata led to the isolation of deoxylycorenine (1), O-demethylhomolycorine (2), galanthamine (3), lycoramine (4), mixture of $6{\alpha}$-and $6{\beta}$-haemanthidine (5), and lycorine (6), identified by spectroscopic data and physicochemical property. Among the isolated compounds, 1, 3 and 6 showed acetylcholinesterase inhibitiory activities with $IC_{50}$ values of 18.0, 12.0 and $16.6\;{\mu}M$, respectively, in in vitro colorimetric microplate assay.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1-4
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• 2005

This paper describes work on isolation of vibration related engine by a hydraulic engine mount with controllable area of inertia track. Automotive engine mounts are required to constrain motion of engine shake resulting from low-frequency road input of shock excitation and also to isolate noise and vibration generated by the engine with unbalanced disturbance at the high frequency range. The property of the mount depends on vibration amplitude and excitation frequency, which means that the excitation amplitude is large in low excitation frequency range and small in high frequency range. In this paper, theoretical works with model of the mount to reduce vibrations related engine were conducted. The volumetric stiffness of the mount is greatly changed according to the switching the area of the inertia track. Therefore, when the area of the inertia track is tuned, the transmissibility of the mount is effectively reduced.

• Korean Journal of Veterinary Service
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• v.18 no.2
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• pp.124-132
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• 1995

The present study was conducted to investigate the incidence of Pasteurella multocida infection in cheju swine from March 1994 to December 1994 isolated organisms were identified by the biochemical properties, cellulose serological type and antibiotic susceptibilities. Pasteurella multocida was isolated from the Lungs of 96 pigs with pneumonia(51 %) among 188 slaughtered pigs. The majority of p multocida isolates were identical to those of the standard strains. On the classification of the capsular type of the isolated p multocida it consist of the 88 isolates of type A(91.6%) 2 isolates of type D (2%) and un classified 6 types(6.2%). The majority of the 96 isolates of p multocida highly susceptible to the antibiotics including ampicillin(Am), cephalotin(Ce), erythromycin(Em), gentamycin(Gm), kanamycin(Km), lincomycin(Lm), neomycin(Nm), penicillin(Pc), streptomycin(Sm), solfametoxazol/trimethoprim(Sxt) and tetracycline(Te)

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.03a
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• pp.465-472
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• 2003

The main concept of base isolation system is to reduce the member forces by decreasing the earthquake forces transmitted to superstructure instead of the conventional techniques of strengthening the structural members. There are two important advantages in friction pendulum systems. The functions of carrying the vertical load and of providing horizontal stiffness are effectively separated. This results in a more stable system that eliminates the need of a fail-safe mechanism. Friction pendulum systems are less sensitive to variations in the frequency content of ground excitation and tend to limit the intensity of the farce imparted to the superstructure. This study investigates the friction coefficients on the FPS test specimens according to the velocity, bearing pressure and test waveform.

• Journal of Navigation and Port Research
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• v.32 no.2
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• pp.133-140
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• 2008

In this paper, a fault detection method for operator failures using the observation technique is proposed. The suggested algorithm is extended using the conventional sensor/actuator fault detection method. First, it is assumed that operator failure affects human work operations, as it is an external input signal. With this assumption, a human work model with operator failure is suggested. Second, an unknown input observer with proportional and integral gains is introduced. The characteristic of this observer of estimating an external signal without an exact input is shown, and the conditions for the detection of an operator failure are proposed. Finally, by simulating the container crane operations, it is verified that the observer can accurately detect an operator failure and estimate its magnitude from the given internal signal.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.03a
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• pp.367-372
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• 2002

In these days, The base isolation system is often used to improve the seismic capacity of the structures instead of conventional techniques of strengthening the structural members. The purpose of this study is to evaluate dynamic properties and mechanical characteristics of the 10tonf-LRB(Lead-Rubber Bearing). Experimental studies were performed to obtain the hysteretic behavior, effective shear stiffness( $K_{eff}$), equivalent damping( $H_{eq}$ ), capacity of energy dissipation( $W_{D}$) of six 10tonf-LRB. Especially, in this study, the response of the LRB for high loading frequency(0.5Hz~3.0Hz) was estimated. The effective shear stiffness of the LRB decreases and the capacity of energy dissipation increases as the shear strain amplitude increases. But the shear behavior of the LRB is not affected sensitively by loading frequency.y.y.

• Earthquakes and Structures
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• v.6 no.2
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• pp.127-140
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• 2014

Laminated rubber bearing is very popular base isolation of earthquake engineering pertaining to the passive structural vibration control technologies. Rubber used in fabricating NRB and LRB can be easily attacked by various environmental factors such as oxygen, heat, light, dynamic strain, and organic liquids. Among these factors, this study carried out thermal aging test to investigate the effect of thermal aging on the mechanical properties of laminated rubber bearings in accelerated exposure condition of $70^{\circ}C$ temperature for 168 hours. The compressive-shear test was carried out to identify the variation of compressive and shear properties of the rubber bearings before and after thermal aging. In contrast to tensile strength and elongation tests, the hardness of rubber materials showed the increasing tendency dependent on exposure temperature and period. Based on the test results, the property changes of rubber bearing mainly aged by heat are quantitatively presented.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.7
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• pp.517-523
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• 2003

This paper presents response property of the squeeze mode type mount using Magneto-Rheological fluid (MR fluid) . The MR mount for the isolation of multi-directional vibrations was constructed in this study. Both the mechanism and shape of the mount are the same as squeeze film dampers for a rotor system. In the present work, the performance of the mount was experimentally Investigated according to the magnetic field strength. The experimental results present that the MR mount can effectively reduce the vibration in a wide range of frequency by controlling the applied electromagnetic filed strength. Viscous damping and stiffness coefficients of the MR mount tend to be changed according to the variation of the applied currents In this study.