• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.6
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• pp.809-817
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• 2013

The aim of this study was to evaluate the mechanism of vasodilation of Lespedezea cuneata(LC) in rabbit common carotid artery and cavernosal smooth muscle. LC relaxed arterial strips precontracted with norepinephrine and cavernosal strips precontracted with phenylephrine. The arterial relaxation effects of LC was endothelium-dependent. $N{\omega}$-nitro-L-arginine(L-NNA), NOS inhibitor, methylene blue(MB), cGMP inhibitor, indomethacin(IM), cyclo-oxygenase inhibitor and tetraethylammonium chloride(TEA), KCa-channel blocker attenuate the relaxation responses of LC in arterial strips. In $Ca^{2+}$-free krebs-ringer solution, pretreatment of LC extract significantly reduced the contraction induced by addition $Ca^{2+}$. L-NNA reduced LC extract-induced relaxation in cavernosal strips, but IM, TEA and MB didn't affect LC extract-induced relaxation. When LC extract was applicated on human umbilical vein endothelial cell, the nitric oxide concentration was increased. We conclude that in rabbit common carotid artery, LC may suppress influx of extra-cellular $Ca^{2+}$ through the release of endothelium derived relaxing factor including nitric oxide, prostacyclin, endothelium derived hyperpolarizing factor. And LC exerts a relaxing effect on corpus cavernosum through activating the NO.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.8
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• pp.658-663
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• 2002

Hall factor of electrons in $\Gamma$-valley is calculated as functions of temperature, impurity concentration, and nonparabolicity of conduction valleys by taking into account the current density obtained from the Boltzmann transport equation. The dependence of the Hall factor on the temperature is clearly shown in the case of the optical phonon scattering and that on the impurity concentration is obvious in the case of the ionized impurity scattering. As the nonparabolicity of the conduction band increases, the Hall factor due to the acoustic or optic phonon scattering increases, whereas that due to the ionized impurity scattering decreases. The change of the Hall factor can be analysed in terms of the dispersion of relaxation time.

• Journal of the Korean Data and Information Science Society
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• v.8 no.2
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• pp.111-118
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• 1997

Adding a noise tolerance factor to the Relaxation learning algorithm in Hop-field network improves noise tolerance without effecting storage capacity. The new algorithm is called the Pseudo-Relaxation algorithm, and the convergence of the algorithm has been proved. It is also shown that the noise tolerance factor does not effect learning speed.

• The Journal of the Korea Contents Association
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• v.17 no.4
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• pp.247-255
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• 2017

The study figured out the preference factors which should be considered for investor on decision making of unsold apartment and analyzed by comparing the difference according to the type. Then, it investigated the preference factors through the previous studies to analyze the influence factor of decision making and demonstrated the effects through the PLS (Partial Least Squares) regression. In addition, it separated the target type to tenants and construction firms and carried out the survey for comparing the preference factors of investor type. The result of analysis found out that tenants emphasis on preference factors such as the internal factor (1.141), conditional relaxation (1.114), environment factor (1.107), social factor (1.048), external factor (1.030), educational environment factor (1.010) and etc. Then, construction firms emphasis on preference factors such as the social factor (1.401), environment factor (1.251), conditional relaxation (1.133) and etc. In addition, common preferences factors are the conditional relaxation, social factor, environment factor.

• Journal of the Korean Chemical Society
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• v.56 no.1
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• pp.20-27
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• 2012

Complex permittivity spectra of Allyl Chloride (AC), 2-Butanone (2-BU) and their binary mixtures over the entire range of concentration were obtained using the Time Domain Reflectometry (TDR) technique in microwave frequency range at various temperatures. Static dielectric constant and relaxation time are obtained from complex permittivity spectra. Density ($\rho$) and refractive index ($n_D$) are also measured. These parameters are used to determine excess dielectric constant, excess inverse relaxation time, excess molar volume, excess molar refraction, polarity, Bruggeman factor and thermodynamic parameters viz. enthalpy of activation and entropy of activation. The values of static dielectric constant and relaxation time increases while density and refractive index decreases with the percentage of 2-Butanone in Allyl Chloride increases. Excess parameters were fitted to a Redlich-Kister equation.

• Bulletin of the Korean Chemical Society
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• v.25 no.9
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• pp.1403-1407
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• 2004

Dielectric relaxation measurements on 3-nitrotoluene (3-NT) mixture of dimethylacetamide (DMA), dimethylformamide (DMF) and dimethysulphoxide (DMSO) have been carried out across the entire concentration range using Time domain reflectometry technique at 15, 25, 35 and $45^{\circ}C$ over the frequency range from 10 MHz to 20 GHz. For all the mixtures, only one dielectric loss peak was observed in this frequency range and the relaxation in these mixtures can be well described by a single relaxation time using Debye model. Bilinear calibration method is used to obtain complex permittivity ${\varepsilon}^{*}({\omega})$ from complex reflection coefficient ${\rho}^{*}({\omega})$ over frequency range 10 MHz to 20 GHz. The excess permittivity, excess inverse relaxation time, Kirkwood correlation factor, molar energy of activation are also calculated for these mixtures to study the solute-solvent interaction.

• Transactions on Electrical and Electronic Materials
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• v.18 no.4
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• pp.211-216
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• 2017

The dielectric properties of two polyurethanes (PUs) with different hard segments, i.e., aromatic methylene di-p-phenyl diisocyanate (MDI) and aliphatic hexamethylene diisocyanate (HDI), were investigated in the temperature range of -100 to $100^{\circ}C$ and in the frequency range of 1 Hz to 3 kHz. The ${\alpha}$-relaxations induced by the glass transition of the equivalent soft segments in the two PUs occurred at relaxation times of ${\tau}=3.46{\times}10^{-3}s$ for MDI-PU and ${\tau}=3.39{\times}10^{-2}s$ for HDI-PU at $-20^{\circ}C$, in accord with the temperature-frequency superposition principle, resulting in similar shifting factors. However, different I-relaxations were observed for the two PUs. The I-relaxation of MDI-PU occurred due to the mobility of the chain extenders near $80^{\circ}C$ with a slower shifting rate than the ${\alpha}$-relaxation. On the other hand, I-relaxation arising from both the extender and the unconstrained hard segments of HDI-PU occurred at $70{\sim}100^{\circ}C$, indicating complicated dielectric behavior due to partial interaction with the ${\alpha}$-relaxation at high frequencies. Thus, the I-relaxation of HDI-PU did not follow the superposition principle. The dielectric behaviors of the PUs were mainly influenced by their phase transitions, which were affected by the structure and components of the materials.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.262-265
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• 1999

We report the activation energies which is calculated by adding a term being neglected usually, and magnetic relaxation effects for the surface barrier. The activation energies U at initial magnetization m (m$_{en}$ and m$_{ex}$) and equilibrium magnetization m$_{eq}$ are nearly similar to those of Burlachkov, but the m dependence of the activation energy U is remarkably different. The relaxation effects, which were determined by the m dependence of the activation energies U, are nonlinear for vortex entry, but linear at the initial stage and nonlinear at m(Int) ${\simeq}$ m$_{eq}$ for vortex exit. During relaxation process, the vortex entry at m = m$_{en}$ is faster than the vortex exit at m = m$_{ex}$ by about factor 90. The vortex exit at m = m$_{eq}$ is faster than one at m = m$_{ex}$ by about factor 1.3

• Bulletin of the Korean Chemical Society
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• v.27 no.12
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• pp.2040-2044
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• 2006

Dielectric studies of methyl acrylate with 1-propanol, 1-butanol, 1-heptanol and 1-octanol binary mixtures have been carried out over the frequency range from 10 MHz to 10 GHz at temperatures of 283, 293, 303 and 313 K using Time Domain Reflectometry (TDR) for various concentrations. The Kirkwood correlation factor and excess inverse relaxation time were determined and discussed to yield information on the molecular structure and dynamics of the mixture. The values of the static dielectric constant, relaxation time and the Kirkwood correlation factor decrease with increased concentration of methyl acrylate in alcohol. The Bruggman plot shows a non-linearity of the curves for all the systems studied indicates the heterointeraction which may be due to hydrogen bonding of the OH group of alcohol with C=O of the methyl acrylate. The excess inverse relaxation time values are negative for all the systems at all the temperatures indicates that the solute-solvent interaction hinders the rotation of the dipoles of the system.

• The Journal of Engineering Geology
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• v.10 no.3
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• pp.217-223
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• 2000

Microcracks that consist of quarry planes of granite are an essential factor affecting the long-term behavior of granite. In this paper, fine-grained granite distributed in the Tsukuba area of Japan was selected and microcracks were measured by using scanline method. In addition, a new relaxation testing equipment was developed to carry out stress relaxation test under water-saturated triaxial condition. Based on the relaxation test results with the initial stress level of 75%, the axial stress is decreased by 39%-49% just after the start of the tests, and the totally relaxed stress is 10∼24 MPa in 190 ERT (Elapsed relaxation time, hour). In addition, the relaxed stress is increased with the density of cracks which are parallel to axial load direction.