• Journal of the Society of Cosmetic Scientists of Korea
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• v.25 no.1
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• pp.55-68
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• 1999

A muti-lamellar emulsion containing a pseudoceramide, N-Ethanol-2-myristyl/ palmityl-3-oxostearmide/arachidamide(PC-9) has been prepared and its efficacy evaluation has been investigated. In order to prepare a muti-lamellar emulsion, first, the gram ratios of PC-9, fatty acid and cholesterol on the phase diagram to be capable of forming their lamellar liquid crystal structures were determined and secondly, the multi-lamellar emulsion was preprared using glyceryl monostearate and polyoxyethylene glyceryl monosteartate as emulsifers together with above mentioned pseudo-stratum corneum lipid components. Besides natural oils such as olive oil had a tendency to build up the multi-lamellar emulsion. And according as the amount of oil increased in the emulsion, it was observed that the optical anisotropy of “Maltese Cross” which was a typical configuration of multi-lamella mesophase texture diminished. In the dried state of the multi-lamella emulsion, it was examined to transform its emulsion phase into a lamella liquid crystal one. And finally, when the emulsion was applied into a human skin, it was investigated that it had effectiveness in reducing transepidermal water loss (TEWL) of the skin.

• Economic and Environmental Geology
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• v.31 no.3
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• pp.235-247
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• 1998

A new technique of simultaneons inversion for 3-D seismic velocity structure by using direct, reflected, and refracted waves is applied to the center of the Korean Peninsula including Pyongnam Basin, Kyonggi Massif, Okchon Fold Zone, Taebaeksan Fold Zone, Ryongnam Massif and Kyongsang Basin. Pg, Sg, PmP, SmS, Pn, and Sn arrival times of 32 events with 404 seismic rays are inverted for locations and crustal structure. 5 ($1^{\circ}$ along the latitude)${\times}6$ ($0.5^{\circ}$ along the longitude) ${\times}8$ block (4 km each layer) model was inverted. 3-D seismic crustal velocity tomography including eight sections from the surface to the Moho, eight profiles along latitude and longitude and the Moho depth distribution was determined. The results are as follows: (1) the average velocity and thickness of sediment are 5.15 km/sec and 3-4 km, and the velocity of basement is 6.12 km/sec. (2) the velocities fluctuate strongly in the upper crust, and the velocity distribution of the lower crust under Conrad appears basically horizontal. (3) the average depth of Moho is 29.8 km and velocity is 7.97 km/sec. (4) from the sedimentary depth and velocity, basement thickness and velocity, form of the upper crust, the Moho depth and form of the remarkable crustal velocity differences among Pyongnam Basin, Kyonggi Massif, Okchon Zone, Ryongnam Massif and Kyongsang Basin can be found. (5) The different crustal features of ocean and continent crust are obvious. (6) Some deep index of the Chugaryong Rift Zone can be located from the cross section profiles. (7) We note that there are big anisotropy bodies near north of Seoul and Hongsung in the upper crust, implying that they may be related to the Chugaryong Rift Zone and deep fault systems.

• Geophysics and Geophysical Exploration
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• v.8 no.1
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• pp.41-49
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• 2005

We have developed a random heterogeneous velocity model with bimodal distribution in methane hydrate-bearing Bones. The P-wave well-log data have a von Karman type autocorrelation function and non-Gaussian distribution. The velocity histogram has two peaks separated by several hundred metres per second. A random heterogeneous medium with bimodal distribution is generated by mapping of a medium with a Gaussian probability distribution, yielded by the normal spectral-based generation method. By using an ellipsoidal autocorrelation function, the random medium also incorporates anisotropy of autocorrelation lengths. A simulated P-wave velocity log reproduces well the features of the field data. This model is applied to two simulations of elastic wane propagation. Synthetic reflection sections with source signals in two different frequency bands imply that the velocity fluctuation of the random model with bimodal distribution causes the frequency dependence of the Bottom Simulating Reflector (BSR) by affecting wave field scattering. A synthetic cross-well section suggests that the strong attenuation observed in field data might be caused by the extrinsic attenuation in scattering. We conclude that random heterogeneity with bimodal distribution is a key issue in modelling hydrate-bearing Bones, and that it can explain the frequency dependence and scattering observed in seismic sections in such areas.

• Journal of Korea Water Resources Association
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• v.50 no.7
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• pp.455-465
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• 2017

Understanding of the two-dimensional velocity field is crucial in terms of analyzing various hydrodynamic and fluvial processes in the riverine environments. Until recently, many numerical models have played major roles of providing such velocity field instead of in-situ flow measurements, because there were limitations in instruments and methodologies suitable for efficiently measuring in the broad range of river reaches. In the last decades, however, the advent of modernized instrumentations started to revolutionize the flow measurements. Among others, acoustic Doppler current profilers (ADCPs) became very promising especially for accurately assessing streamflow discharge, and they are also able to provide the detailed velocity field very efficiently. Thus it became possible to capture the velocity field only with field observations. Since most of ADCPs measurements have been mostly conducted in the cross-sectional lines despite their capabilities, it is still required to apply appropriate interpolation methods to obtain dense velocity field as likely as results from numerical simulations. However, anisotropic nature of the meandering river channel could have brought in the difficulties for applying simple spatial interpolation methods for handling dynamic flow velocity vector, since the flow direction continuously changes over the curvature of the channel shape. Without considering anisotropic characteristics in terms of the meandering, therefore, conventional interpolation methods such as IDW and Kriging possibly lead to erroneous results, when they dealt with velocity vectors in the meandering channel. Based on the consecutive ADCP cross-sectional measurements in the meandering river channel. For this purpose, the geographic coordinate with the measured ADCP velocity was converted from the conventional Cartesian coordinate (x, y) to a curvilinear coordinate (s, n). The results from application of A-VIM showed significant improvement in accuracy as much as 41.5% in RMSE.