• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.169-179
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• 2003

Undrained shear strength of clay deposit is one of the most important properties in the design of geotechnical structures. The use of piezocone test is rapidly growing due to its merit that can measure the in-situ undrained shear strength continuously with less error. The reliability of the shear strength from piezocone test depends upon the cone factor applied. Many researchers have suggested different ranges of values for the factors. This study performs to find out the validity of the suggested values in Korea and their charateristics related to the mechanical properties of clay. Piezocone tests were performed at the site of pilot project of ground improvement at Yangsan-Mulgeum Gyeongnam to investigate the charateristics of piezocone factors. The piezocone fators$(N_{kt}, N_{ke}, N_{\Delta u})$ based on the undrained shear strength from quick triaxial compression test are generally within the suggested range. And there appears considerable relations between undrained shear strength and $(N_{kt}, N_{ke}, N_{\Delta u})$ and between preconsolidation pressure and $(N_{kt}, N_{ke})$, while plasticity index, rigidity index and friction ratio do not show any relations with cone factors. The results also reveal that factor $(N_{\Delta u})$ shows higher reliability than factors $(N_{kt} and N_{ke})$, which show smaller standard deviation, breadth of change and scattering.

• Korean Journal of Environmental Agriculture
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• v.12 no.3
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• pp.230-238
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• 1993

To develop multifunctional microorganisms for effective wastewater treatment, the cell of P. aeruginosa P1 enable to accumulate lead in its cell were conjugated with the cell of P. fluorescens S1 enable to degrade efficiently synthetic detergents. The plasmids of the P. aeruginosa P1 and the P. fluorescens S1 were found in the cell of the conjugants when determined by agarose gel electrophoresis. The conjugants obtained from P. fluorescens S1 as a recipient cell and P. aeruginosa P1 as a donor cell possessed the ability to degrade synthetic detergents as well as to accumulate lead.

• The Journal of Engineering Geology
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• v.1 no.1
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• pp.19-37
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• 1991

The geology of the northwestern Cheju Island consist of Pleistocene to Holocene volcanic rocks which could be devided into basalt layers, the Sungsan Formation composed mainly of volcaniclastic debris exposed along the shoreline, and more than 30 cinder cones. Columnar joints and vesicles are dominant in the basalts of the Pyeosunri and the Sihungri basalt Formations. Volcaniclast and clay layers are intercalated in basaltic layers. When volcaniclast of the interlayers would be swept away by ground water and some caves of channel shape would be formaed. Overlying lavas cracked by columnar joints could be easily destroyed, collapsed and/or sunk. Geomechananical nature of the rocks such as strength may be controlled by the vesicularity(size, shape, and orientation of the vesicles) of the rocks. On the basis of vesicularity as a factor of strength, the effective strength ratio(Ke) could be calculated as Ke=0.3-0.72, in which the smaller Ke value reflects the lower in internal stress. In the studied area, the strength of the rocks tends to decrease as increasing in altitude of provenance of the rocks. The rocks in the area show relatively low values in angle of failure strength($\phi$) ranging from 10$^{\circ}$ to 30$^{\circ}$. In conclnsion, the rocks in question, majority of which the critical value exceeds 0.33, belong to the unstable rocks in the aspect of engineering geology.

• Journal of radiological science and technology
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• v.40 no.4
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• pp.605-611
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• 2017

The structure of the actual detector was computed using the code of the PENELOPE. Using the standard mixed sources (450, 1,000 ml), compare the effectiveness of each energy according to various densities and height of the PENELOPE computer simulation, and calculate the effectiveness of the various environmental specimens and apply them to various environmental specimens to determine the lower limit. The values obtained by the obtained value were obtained by applying the obtained efficiency to the actual environmental specimens and obtaining the lower limit values. The density correction factor is 1.155 g of the density correction factor of $0.4g/cm^3$ (59.54keV), 1.153 (661 keV), $1.06g/cm^3$ 1.064 (1,836.04keV), 1.03, and 1.033. It was confirmed that the radioactivity concentration of environmental samples decreased as the amount of specimen was measured increases, and the MDA value decreased as time measured increases.

• Journal of the Korean Society of Radiology
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• v.17 no.2
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• pp.175-184
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• 2023

Based on the actual shape of the detector and the data provided by the manufacturer, the shape of the detector was implemented through Penelope simulation and applied to the appropriate four-layer thickness based on the efficiency obtained from the measurements. Efficiency calculations to determine the effect of the simulated number of Full Energy Peak Efficiency(FEPE) channels in the detector and the outside contact layer in the crystal on the Full Energy Peak Efficiency were performed for various four-layer thicknesses of 0.3, 0.5, 0.7, 1.0, 1.2, and 1.4 mm using the Penelope Code. When the thickness of the external contact layer was increased by 5 times, the Full Energy Peak Efficiency decreased by about 36% for 59.50 keV, and the Full Energy Peak Efficiency decreased by 10% for 1836. In addition, as it increased by 10 times, the Full Energy Peak Efficiency decreased by about 20% for 59.54 keV, and 7% for 1836.01 keV. The Penelope simulated Full Energy Peak Efficiency channel decreases exponentially with the increase in the four layers. In addition, it was confirmed that the total effect curve was well matched with a relative difference of less than 3.5% in the 0.3-1.4 mm dead layer thickness region. However, it was found that the inhomogeneous dead layer is still a parameter in the Monte Carlo model.

• Applied Chemistry for Engineering
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• v.21 no.4
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• pp.401-404
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• 2010

The ion-beam induced changes in the characteristics of gadolinium doped ceria (GDC) pellets have been studied by UV-visible spectroscopy (UV-vis), SEM, and XRD. Implanted ions were protons or Xe ions with the energy of 120 keV or 5 MeV. Densely sintered pristine GDC pellets have cubic fluorite structure and are brown in color. As the ion irradiation proceeded, its color gradually turned into light black and finally into dark black. XRD patterns of GDC pellets were closely related with ion energy and the penetration depth of X-ray. It showed that upon the ion irradiation (120 keV) the lattice parameter of the cubic fluorite phase just beneath the surface is increased.

• Journal of The Korean Astronomical Society
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• v.47 no.4
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• pp.147-152
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• 2014

We present measurements of the Fe $K{\alpha}$ emission line of the intermediate polar V1223 Sagittarii observed with the Suzaku satellite. The spectrum is modeled with an absorbed thermal bremsstrahlung spectrum and three Gaussians for the three components of the Fe $K{\alpha}$ lines. We resolve the neutral or low-ionized (6.41keV), He-like (6.70keV), and H-like (7.00keV) iron lines. We also obtain a thermal continuum temperature of 25 keV, which supports a thermal origin of the hard X-rays observed from the shock heated layers of gas between the white dwarf and the shock front. Hence, we believe that the He-like and H-like lines are from the collisional plasma. On the origin of the Fe $K{\alpha}$ fluorescence line, we find that it could be partly from reflections of hard X-rays from the white dwarf surface and the $N_H$ absorption columns. We also discuss the Fe $K{\alpha}$ emission line as veritable tool for the probe of some astrophysical sites.

• Composites Research
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• v.18 no.6
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• pp.40-47
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• 2005

In this study, we tried to invent ceramic armor material with brilliant ballistic properties by the silica of the high compression-expansion ratio and based on alumina that has the most economical and higher ballistic efficiency. After we choose three compositions, proper sintering temperature for each composition was decided. After physical/mechanical measurement, we measured ballistic properties about KE(Kinetic Energy, L/D=10.7, tungsten heavy alloy) and HEAT(High Explosive Anti-Tank, K215) projectiles. As a result, $46\%\;Al_2O_3\;-\;51\%\;SiO_2$ of three compositions had the highest ballistic efficiency md better properties than alumina.

• Journal of Korean Medical classics
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• v.25 no.2
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• pp.1-13
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• 2012

Objective : Zhang, Zhongjing(張仲景)'s Sanghanlun(傷寒論) is based on Six-channels system(六經) to classified a disease. But the notion of Six-channels system seems to be a very various angles. For example, Meridian and collateral theory(經絡說), Viscera and Bowels theory(臟腑說), Grade theory(段階說), Surface theory(地面說), Symptoms theory(症候群說), Six-disease theory(六病說), Eight principle pattern theory(八綱說) and all the rest of it. Above all things Meridian and collateral theory was very frequently quoted to explain the Six-channels system(六經). But it's true notion is not restrict to a meridian vessel(經脈). Method : I will try to describe the Sanghanlun's Greater yang disease(太陽病) through the Ke-qin(柯琴)'s Taiyangbingjie(太陽病解), and I would like to point out that the existing perception that Greater yang(太陽) is connected with Bladder meridian(足太陽膀胱經) is wrong. Result : Ke-qin's Taiyangbingjie explained the greater yang disease was connected with Heart(yang within yang), which was located in the top half and the outer layer of the body. In addition to the presence of the diaphragm or lungs are involved with. Conclusion : Practical meaning of greater yang disease is not connect with Bladder meridian, but it is related to the Heart and Lung for maintain the Nutrient and defense circulation (營衛循環).

• Nuclear Engineering and Technology
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• v.52 no.2
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• pp.456-460
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• 2020

In this research, a radiation detection backpack to be used discreetly or by a wide range of users was developed using array silicon-photomultiplier (SiPM) and CsI (Tl), and its characteristics were evaluated. The R-squared value, which indicates the responsiveness of a detector based on the signal intensity, was determined to be 0.981, indicating a good linear responsivity. The energy resolutions for gamma radiation energies of Co-57 (122 keV), Ba-133 (356 keV), Cs-137 (662 keV), and Co-60 (1332 keV) were found to be 13.40, 10.50, 6.77, and 3.16%, respectively. These results confirm good energy resolution characteristics. Furthermore, in the case of mixed sources, the gamma radiation peaks were readily distinguishable, and the R-squared value for energy linearity was calculated to be 0.999, demonstrating an exceptional energy linearity. Further research based on the results of this study would enable the commercialization of lightweight SiPM-based wireless radiation detection backpacks that can be used for longer durations by replacing the photomultiplier tube, which is mainly used as the optical sensor in existing radiation detection backpacks.