• Structural Engineering and Mechanics
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• v.34 no.5
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• pp.663-666
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• 2010

The spectral content of ground displacement of the 10 largest last California earthquakes is studied. Specifically, the power spectral density function of the critical horizontal-component record of the closest-to-epicenter station is analyzed in each case. The results permit to state that horizontal ground displacement is a narrow-band process. This fact was previously noticed while trying to solve the large-base-displacement problem in isolated structures and it was fundamental in the solution of this issue; however, these preliminary results were limited in number to enable a statement like the foregoing one. Thus, the broader results presented herein were necessary.

• Journal of applied mathematics & informatics
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• v.29 no.3_4
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• pp.1011-1016
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• 2011

In this paper, our main purpose is to establish the existence of positive bounded entire solutions of second order quasilinear elliptic equation on $R^N$. we obtained the results under different suitable conditions on the locally H$\"{o}$lder continuous nonlinearity f(x, u), we needn't any mono-tonicity condition about the nonlinearity.

• Journal of Photoscience
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• v.10 no.1
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• pp.149-155
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• 2003

The absorption, fluorescence and fluorescence-excitation spectra of concentrated toluene solutions of selected para substituted trans-stilbene derivatives provide strong evidence for aggregation. A red-shifted fluorescence spectrum peaking at 420 nm gains in intensity as the stilbene concentration is increased. The excitation spectrum of this new emission is well to the red of the normal stilbene absorption spectrum, consistent with the appearance of a red shifted shoulder in the UV spectrum. Formation of a fluorescent ground state dimer (or higher aggregate) is proposed to account for these observations. The presence of polar substituents is crucial to the formation of this ground state complex.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.11
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• pp.736-739
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• 2014

In this paper, we propose a enhanced anti-corrosion property of the ground system by coating the CNT/PVDF composite film on it. Polymer material used for preventing the corrosion of ground system is polyvinylidene fluoride (PVDF), and conducting filler for obtaining conductivity of the composite film is multi-walled carbon nanotubes (MWCNTs). The MWCNTs were dispersed in the organic solvent of methyl ethyl ketone 2-butanone (MEK) with different concentration ratios, and the PVDF was solved in the MEK solvent with constant concentration ratio of 1 wt%. The CNT/PVDF composite solution was perpared by mixing and re-dispersing the CNT solution and the PVDF solution. Finally, the CNT/PVDF composite films were fabricated by the spray coating method using the above composite solution. Electrical conductivity, surface states, and anti-corrosion property of the CNT/PVDF composite films coated on the Cu substrate were evaluated. We found that the CNT/PVDF composite film showed relatively low resistance, hydrophobic surface state, and chemical stability. Consequently, we could improve the anti-corrosion property and maintain the electrical conductivity of the ground system by coating the CNT/PVDF composite film on it.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.309-312
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• 2002

This paper reviews depositional environments, consolidation characteristic of marine deposits along the Nam-Yang river mouth and then analytical solution of self-weight consolidation is made to find consolidated state. This area has been deposited through the short geological age(22year). It's deposition rate is as high as 70cm/year and the height of deposition may be $3{\sim}12m$. It's known that this area is in the under-consolidated state from OCR and analytical solution. It is conclude that the under-consolidated state should be considered in prediction of consolidation settlement.

• Bulletin of the Korean Chemical Society
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• v.11 no.2
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• pp.115-118
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• 1990

Solution and frozen solution EPR spectra of $\alpha-1,2,3-[HPV(IV)V_2W_9O_{40}]^{6-}$ have been analyzed. The isotropic hyperfine coupling constants remain constant at 350-77 K, indicating that the unpaired electron is delocalized over three vanadium atoms probably even in the ground state.

• Interaction and multiscale mechanics
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• v.5 no.2
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• pp.131-144
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• 2012

We study a radial basis function collocation method (RBFCM) to discretize a coupled nonlinear Schr$\ddot{o}$dinger equation (CNLSE) that governs a two dimensional rotating Bose-Einstein condensate (BEC) with an angular momentum rotation term. We exploit a RBFCM-continuation method (RBFCM-CM) to trace the solution curve of the CNLSE. We compare the performance of the RBFCM-CM with the FEM-CM. We observe that the RBFCM-CM is very robust in a coarse grid for resolving the ground state solution with many vortices when the angular momentum rotation is close to the limit. Numerical results demonstrate the efficiency and accuracy of the RBFCM-CM for computing the superfluid density of the ground level of the BEC.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.2
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• pp.183-204
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• 2007

When a tunnel is excavated below groundwater table, the groundwater flows into the excavated wall of tunnel and seepage forces are acting on the tunnel wall. Such seepage forces significantly affect the ground reaction curve which is defined as the relationship between internal pressure and radial displacement of tunnel wall. In this paper, seepage forces arising from the ground water flow into a tunnel were estimated quantitatively. Magnitude of seepage forces was decided based on hydraulic gradient distribution around tunnel. Using these results, the theoretical solutions of ground reaction curve with consideration of seepage forces under steady-state flow were derived. A no-support condition and a supported condition with grouted bolts and shotcrete lining were considered, respectively. The theoretical solution derived in this study was validated by numerical analysis. The changes in the ground reaction curve according to various cover depths and groundwater table conditions were investigated. Based on the results, the application limit of theoretical solutions was suggested.

• Bulletin of the Korean Chemical Society
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• v.18 no.9
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• pp.1006-1010
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• 1997

The nature and analysis methods of complicated decay profiles found in forced Rayleigh scattering (FRS) have been investigated for the probe diffusion of methyl yellow in 2-propanol. The complementary shifted and ground state grating effect, which is known to be the origin of non-single exponential decays, was analyzed by non-linear regression fitting to a double exponential model function. We confirmed that the parameters were highly correlated so that it was difficult to extract a unique set of parameters in the presence of experimental noise. Nevertheless, a reasonable range of decay time constants could be estimated from the grating spacing dependence.

• Bulletin of the Korean Chemical Society
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• v.20 no.7
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• pp.796-800
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• 1999

Three anthrylazacrown ethers in which the anthracene fluorophore π system is separated from the electron donor atoms by one methylene group were synthesized, and their photophysical study was accomplished. These fluorescent compounds showed a maximum fluorescence intensity at pH=5 in aqueous solutions and a decrease in fluorescence intensity upon binding of paramagnetic metal cations (Mn 2+ (d 5 ), Co 2+ (d 7 ), Cu 2+ (d 9 )). The decrease in fluorescence intensity may be attributed to the paramagnetic effect of metal cations to deactivate the excited state by the nonradiative quenching process. The benzylic nitrogen was found to play an important role in changing fluorescence intensity. From the observed linear Stern-Volmer plot and the fluorescence lifetime independence of the presence of metal ions, it was inferred that the chelation enhanced fluorescence quenching (CHEQ) mechanism in the system is a ground state static quenching process. Enhanced fluorescence was also observed when an excess Na + ion was added to the quenched aqueous solution, and it was attributed to cation displacement of a complexed fluorescence quencher.