• Journal of the Korean Geotechnical Society
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• v.25 no.6
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• pp.5-16
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• 2009

The is study is to evaluate the small strain shear modulus ($G_{max}$) of Busan clay using in-situ penetration tests. A series of dilatometer tests (DMT) and piezocone penetration tests (CPTu) are performed at Busan newport and Noksan sites, and hybrid oedometer tests are also carried out on the specimens obtained from both sites. The $G_{max}$ is evaluated from the shear wave velocity ($V_s$) measured by the bender elements installed at the boundary of oedometer cell. By analyzing these data, the relationship of $G_{max}$ and state variables, such as confined stress and void ratio, is developed. The analysis of lab and in-situ test results reveals that the ratio of $G_{max}$ to $q_t$ is inversely proportional to the plasticity index while the ratio of $G_{max}$ to $E_D$ has a linear relationship with ($I/I_D$)$(p_a/{\sigma}'_v)^{0.5}$. Two correlations suggested in this study, based on CPT and DMT results, appear to provide reasonable predictions of the small strain shear modulus.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1431-1437
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• 2008

The small-strain shear modulus ($G_{max}$) of uncemented sand is affected by the the mean principal stress and void ratio, and it has been known that the cementation and aging also affect to $G_{max}$ of sand. For extensive understanding about the effect of cementation on the $G_{max}$ of sand, a series of bender element tests was conducted on the cemented specimens prepared in a large calibration chamber by pluviation of the sand-gypsum mixture. It was observed from the experimental results that the $G_{max}$ of cemented sand is higher above 10 times than value of uncemented one, and it increases exponentially with the gypsum content increases. Whereas, the increase of the vertical stress from 50kPa to 200kPa and the relative density from 40% to 80% result in 20~30% and 2 times increase of $G_{max}$, respectively. It means that the gypsum content, that is cementation level, is the most influential factor on the $G_{max}$ of cemented sand. In addition, the effect of relative density on $G_{max}$ was more apparent on cemented sand than uncemented one.

• Journal of fish pathology
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• v.22 no.2
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• pp.125-135
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• 2009

The pharmacokinetic properties of oxolinic acid (OA) were studied after oral administration, intraperitoneal injection and dipping to cultured olive flounder, Paralichthys olivaceus (average 90 g, $23{\pm}1{^{\circ}C}$). Plasma samples were taken at 3, 5, 10, 15, 24, 30, 48, 96 and 144 h post-dose. In oral dosage at 15, 30 and 60 ㎎/㎏, the peak plasma concentrations of OA, which attained at 10~15 h post-dose, were 1.92, 2.45 and 3.72 $\mu{g}/m\ell$, respectively. In intraperitoneal injection with 10 and 20 ㎎/㎏, the peak plasma concentrations of OA, which attained at 10 h post-dose, were 4.1 and 4.8 $\mu{g}/m\ell$, respectively. In dipping in 30 and 50 ppm for 1 h, peak concentrations were observed at 5 h and 30 h post-dose, were 0.22 and 0.38 $\mu{g}/m\ell$, respectively. The kinetic profile of absorption, distribution and elimination of OA in plasma were analyzed fitting to a one-compartment model by WinNonlin program. Calculated parameters for a single oral dosage of 15, 30 and 60 ㎎/㎏, respectively, were: AUC (the area under the concentration-time curve)=70.93, 120.0 and 141.86 $\mu{g}$ $h/m\ell$ $T_{max}$ (time for maximum concentration)=16.22, 20.39 and 17.33 h; $C_{max}$ (maximum concentration)=���D1.61, 2.40 and 3.01 $\mu{g}/m\ell$. Following intraperitoneal injection of 10 and 20 ㎎/㎏, these parameters were AUC=184.7 and 315.92 $\mu{g}$ $h/m\ell$ $T_{max}$=5.91 and 6.26 h; $C_{max}$=4.19 and 4.45 $\mu{g}/m\ell$. Following dipping at 30 and 50 ppm, these parameters were AUC=17.58 and 21.69 $\mu{g}$ $h/m\ell$ $T_{max}$=19.08 and 31.43 h; $C_{max}$x=0.22 and 0.25 $\mu{g}/m\ell$.

• Journal of IKEEE
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• v.20 no.3
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• pp.260-264
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• 2016

The MAX77846, which is compatible with MAX77826, is a sub-power management IC (PMIC) for the latest Wearable Watch and 3G/4G smart phones. The MAX77846 contains N-MOSFET (N channel Metal-Oxide Semiconductor Field-Effect Transistor), a high-efficiency regulator, and comparator, etc to power up peripherals. The MAX77846 also provides power on/off control logic for complete flexibility and an $I^2C$ (Inter Integrated Circuit) serial interface to program individual regulator output voltages. In this paper, the simplified power macro-model based on MAX77846 is designed to verify the performance of the battery voltage in terms of current and time, and simulated by using of the LTspice. In addition, it is verified how much time can the charged battery capacity for Samsung Galaxy Gear 2 be used to operate a specified function after measuring the currents flowing to carry out the main functions in real time, which will be applicable to design parameters for the advanced power module

• Microbiology and Biotechnology Letters
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• v.16 no.2
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• pp.85-91
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• 1988

Energy efficiency of bacterial cell mass and product formation from cellulose using Ruminococcus albus and Ruminococcus flavefaciens with application of available electron balance were discussed. Values of true growth yield, η$_{max}$ and η$^{max}_{th}$ and maintenance coefficient, m$_{e}$, were estimated us-ing experimental data, and the results were compared with estimates obtained from theoretical ap-proach. Experimental values were similar in magnitude to theoretical values in $Y^{max}_{ATP}$= 10.5 g cells/ mole ATP. Therefore, $Y^{max}_{ATP}$ values of Ruminococcus albus and Ruminocoecus flavefaciens were considered similar to 10.5 g cells/mole ATP.

• Geomechanics and Engineering
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• v.31 no.3
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• pp.291-304
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• 2022

Maximum shear modulus (G_max or G₀) is an important soil property useful for many engineering applications, such as the analysis of soil-structure interactions, soil stability, liquefaction evaluation, ground deformation and performance of seismic design. In the current study, bender element (BE) tests are used to evaluate the effect of the void ratio, effective confining pressure, grading characteristics (D₅₀, C_u and C_c), anisotropic consolidation and initial fabric anisotropy produced during specimen preparation on the G_max of sand-gravel mixtures. Based on the tests results, an empirical equation is proposed to predict G_max in granular soils, evaluated by the experimental data. The artificial neural network (ANN) and Adaptive Neuro Fuzzy Inference System (ANFIS) models were also applied. Coefficient of determination (R²) and Root Mean Square Error (RMSE) between predicted and measured values of G_max were calculated for the empirical equation, ANN and ANFIS. The results indicate that all methods accuracy is high; however, ANFIS achieves the highest accuracy amongst the presented methods.

• Journal of Biomedical Engineering Research
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• v.43 no.5
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• pp.331-340
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• 2022

Early afterdepolarization (EAD), a significant cause of fatal ventricular arrhythmias including Torsade de Pointes (TdP) in long QT syndromes, is a depolarizing afterpotential at the plateau or repolarization phase in action potential (AP) profile early before completing one pace. AP duration prolongation is related to EAD but is not necessarily accounted for EAD. Several computational studies suggested EAD can form from an abnormality in the late plateau and/or repolarization phase of AP shape. In this sense, we hypothesized the slope during repolarization has the characteristics to predict TdP risk, mainly focusing on the maximum slope during repolarization (dVm/dt_{max_repol}). This study aimed to predict the sensitivity of dVm/dt_{max_repol} to ion channel conductances as a TdP risk metric through a population simulation considering multiple effects of simultaneous reduction in six ion channel conductances of g_NaL, g_Kr, g_Ks, g_to, g_K1, and g_CaL. Additionally, we verified the availability of dVm/dt_{max_repol} for TdP risk prediction through the correlation analysis with qNet, the representative TdP metric. We performed the population simulations based on the methodology of Gemmel et al. using the human ventricular myocyte model of Dutta et al. Among the sixion channel conductances, dVm/dt_{max_repol} and qNet responded most sensitively to the change in g_Kr, followed by g_NaL. Furthermore, dVm/dt_{max_repol} showed a statistically significant high negative correlation with qNet. The dVm/dt_{max_repol} values were significantly different according to three TdP risk levels of high, intermediate, and low by qNet (p<0.001). In conclusion, we suggested dVm/dt_{max_repol} as a new biomarker metric for TdP risk assessment.

• Journal of Satellite, Information and Communications
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• v.12 no.3
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• pp.8-14
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• 2017

In 4G mobile communication, data services of mobile communication began to be provided in earnest. As a result, services such as the internet and multimedia including the video have become the main contents in the recent wireless traffic. Accordingly, research on 5G mobile communication with higher transmission rate has been actively carried out. 5G mobile communication is expected to be based on 4G for compatibility with existing terminals. Therefore, the simulation of this paper is based on 4G and we propose a new user scheduling scheme based on the Max throughput scheduling algorithm to improve system performance. This paper derives the frequency efficiency and fairness to compare the existing user scheduling algorithm with the proposed user scheduling algorithm. The proposed scheme shows better frequency efficiency and fairness than Max throughput in all situations. This paper contributes to the research for improving the system performance of 5G mobile communication technology, and I hope that it will help some of the ongoing standardization work.

• Journal of the Korean Geotechnical Society
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• v.18 no.1
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• pp.29-39
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• 2002

In order to evaluate the behavior of overall range from small strain to failure, the triaxial compression tests with LVDTs were performed for local displacement measurements. According to the result it was possible to evaluate the total range behavior from 0.001% to 10% and both secant moduli of undisturbed and disturbed weathered soils had a similar result in the small slain level. The normalized shear moduli$(G/G_{max})$ in the undrained triaxial compression tests were similar to those of resonant column tests but the maximum shear moduli$(G/G_{max})$ were strongly affected by the ratio of saturation. As a result of parametric study a constitutive model with anisotropic hardening could predict the behavior of total strain range.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.09a
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• pp.98-106
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• 2001

The deformation characteristics of cohesionless soils in Korea were investigated using resonant column tests. Total 60 samples, which were sampled from sedimentary and residual soils and reconstituted using controlled particle-size distributions, were prepared. The confining pressure applied in the tests ranges from 20 kPa to 500 kPa. The test results ware categorized into 3 groups including clean sands, silt and silty sand, and residual soils. Based on test results, the small-strain shear modulus(G$_{max}$) and damping ratio(D$_{min}$) were determined and the effects of confinement on G$_{max}$ and D$_{max}$ were characterized. The empirical correlations predicting G$_{max}$ were suggested for 3 group soils. Nonlinear deformational characteristics of clean sands are significantly affected by confining pressure and the ranges and mean curves for G and D are suggested considering the range of confining Pressure. The silt and silty sand and residual soils were weakly affected by confining pressure, so the representative ranges and curves, independent of confining pressure, were proposed.d.posed.d.