• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.473-473
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• 2011

Group method of data handling neural networks model (GMDH-NNM) is used to estimate daily reference evapotranspiration (ETo) using limited climatic variables such as max temperature ($T_{max}$), min temperature ($T_{min}$), mean wind speed ($W_{mean}$), mean relative humidity ($RH_{mean}$) and sunshine duration (SD). And, for the performances of GMDH-NNM, it consists of training and test performances, respectively. The training and test performances are carried out using daily time series data, respectively. From this research, we evaluate the impact of GMDH-NNM for the modeling of the nonlinear time series data. We should, thus, construct the credible data of the daily ETo data using GMDH-NNM, and can suggest the methodology for the irrigation and drainage networks system. Furthermore, this research represents that the strong nonlinear relationship such as ETo modeling can be generalized using GMDH-NNM.

• Journal of the Korean Society for Heat Treatment
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• v.5 no.1
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• pp.23-31
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• 1992

It is investigated that Fe-C-N compound layer, defusion layer, and induction hardened layer produced by nitrocarburizing blend heat treatment in austenitic temperature with high frequency induction heating of mild steel specimen sprayed sursulf salt-bath. As the temperature of blend-heat treatment got increased, the thickness and hardness of compound layer and diffusion layer were increased. Compound layer(max. $35{\mu}m$), diffusion layer (max. 2.5mm) and induction hardened layer were gained in the shortest time 10 sec and in the case of $1000^{\circ}C$ total hardness depth of those was about 3.5mm. When the blend-heat treated specimen was reheated, maximum hardness of compound layer was dropped more than that of the reheated compound layer after sursulf treated, whereas hardness of diffusion layer was increased.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1439-1442
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• 2010

Time-lag recurrent neural networks model (Time-Lag RNNM) is used to estimate daily pan evaporation (PE) using limited climatic variables such as max temperature ($T_{max}$), min temperature ($T_{min}$), mean wind speed ($W_{mean}$) and mean relative humidity ($RH_{mean}$). And, for the performances of Time-Lag RNNM, it is composed of training and test performances, respectively. The training and test performances are carried out using daily time series data, respectively. From this research, we evaluate the impact of Time-Lag RNNM for the modeling of the nonlinear time series data. We should, thus, construct the credible data of the daily PE using Time-Lag RNNM, and can suggest the methodology for the irrigation and drainage networks system. Furthermore, this research represents that the strong nonlinear relationship such as pan evaporation modeling can be generalized using Time-Lag RNNM.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1596-1599
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• 2010

Group method of data handling neural networks model (GMDH-NNM) is used to estimate daily pan evaporation (PE) using limited climatic variables such as max temperature ($T_{max}$), min temperature ($T_{min}$), mean wind speed ($W_{mean}$), mean relative humidity ($RH_{mean}$) and sunshine duration (SD). And, for the performances of GMDH-NNM, it is composed of training and test performances, respectively. The training and test performances are carried out using daily time series data, respectively. From this research, we evaluate the impact of GMDH-NNM for the modeling of the nonlinear time series data. We should, thus, construct the credible data of the daily PE data using GMDH-NNM, and can suggest the methodology for the irrigation and drainage networks system. Furthermore, this research represents that the strong nonlinear relationship such as pan evaporation modeling can be generalized using GMDH-NNM.

• Journal of the Korean Society of Safety
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• v.17 no.1
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• pp.18-24
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• 2002

This study verified the relationship between fracture mechanics parameters(${\Delta}K,\;K_{max}$) and X-ray parameters ($(\sigma}_r,;B$) for G365 steel at elevated temperature up to $300{\circ}C$. The fatigue crack propagation test were carried out and X-ray diffraction technique according to crack length direction was applied to fatigue fractured surface. The residual stress on the fracture surface was found to increase in low ${\Delta}K$ region, reach to a maximum value at a certain value of $K_{max}$ or ${\Delta}K$ and then decrease. Residual stress was independent on stress ratio by arrangement of ${\Delta}K$ and half value breadth was independent by the arrangement of $K_{max}$. The equation of ${\sigma}_r-{\Delta}K$ was established by the experimental data. Therefore, fracture mechanics parameters could be estimated by the measurement of X-ray parameters.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.58.3-58.3
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• 2016

The Kepler space mission provides quantitative and qualitative photometric time series of oscillating stars. It is possible to examine statistical study with seismic properties of solar-like stars. Global seismic properties - large frequency separation (${\Delta}{\nu}$), frequency of maximum power (${\nu}_{max}$) and amplitude of Gaussian envelope (A) widely have been used to determine empirical scaling relations for inferring the stellar physical quantities - mass, age and temperature. We aim to confirm whether width of Gaussian envelope on power excess (${\delta}{\nu}_{env}$) can be used with parameter of scaling relation before redgiant phase using Kepler data. Therefore we analyze the characteristics of ${\delta}{\nu}_{env}$ of 129 solar-like stars from main-sequence to subgiant. We have demonstrated that ${\delta}{\nu}_{env}$ has highly correlations with global parameters - ${\Delta}{\nu}$ and ${\nu}max$. We have also found the break of ${\delta}{\nu}_{env}-{\Delta}{\nu}$ and ${\nu}_{max}$ relations.

• Advances in Traditional Medicine
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• v.4 no.4
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• pp.227-234
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• 2004

An ${\alpha}-Amylase$ was purified to apparent homogeneity from germinating soybean seeds (Glycine max). Enzyme showed high specificity for starch. ${\alpha}-Amylase$ from soybean has optimum pH at 7.6 in the pH range 4.0-10.6. At this pH, the $K_m$ of starch was 2.63 mg/ml and the $V_{max}$ was equal to 52.6 mg/ml/min protein. Optimum temperature of the enzyme was found to be $55^{\circ}C,\;Q_{10}$ equal to 1.85 and energy of activation equal to 12 kcal/mol. Additives like, EDTA reduced the activity of ${\alpha}-amylase$ whereas PMSF enhanced the activity. ${\alpha}-Amylase$ was inhibited by several heavy metal ions.

• Journal of Korean Society on Water Environment
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• v.24 no.5
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• pp.550-555
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• 2008

This study was conducted to assess the growth characteristics of phytoplankton and to understand seasonal dynamics of phytoplankton in response to limiting nutrients in an agricultural reservoir from November 2002 to December 2003. Marked increase of chl.a concentration observed in July ($99.0{\mu}g/L$) and November ($109.7{\mu}g/L$) after heavy rainfall. TP concentration ranged $48.0{\sim}126.6{\mu}g/L$, and its the temporal variation was similar to that of chl.a concentration. Microcystis spp., dominant phytoplankton species were used for the growth kinetics experiment, except for the season when Aulacoseira spp. (March, April) and Aphanocapsa sp. (May) dominated. In the temperature range between $10{\sim}25^{\circ}C$, the rate of growth increase per $10^{\circ}C$ was almost two folds. The highest maximum growth rate (${\mu}_{max}=1.09day^{-1}$) of phytoplankton observed September, and ${\mu}_{max}$ was lowest ($0.34day^{-1}$) in March when Aulacoseira spp. dominated. The ${\mu}_{max}$ ($0.78{\pm}0.20day^{-1}$) was relatively high in the summer season when water temperature is above $20^{\circ}C$ and cyanobacteria dominated compared to the spring when diatoms dominated ($0.43{\pm}0.08day^{-1}$). The maximum growth rate ($0.55{\pm}0.12day^{-1}$) and the half saturation concentration ($K_s=0.73{\pm}0.15{\mu}M$) of cyanobacteria during winter season (November, December) was higher than those of diatoms. However, the ${\mu}_{max}$ and $K_s$ of cyanobacteria in December was similar to those of diatom, reflecting that diatom cell quota (Mean 48.4 pgP/cell) was greater than cyanobacteria (34.0 pgP/cell) during this time.

• Journal of fish pathology
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• v.23 no.1
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• pp.57-67
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• 2010

Effects of temperature ($13{\pm}1.5^{\circ}C$, $23{\pm}1.5^{\circ}C$) on the pharmacokinetic properties of nalidixic acid (NA), piromidic acid (PA) and oxolinic acid (OA) were studied after oral administration to cultured olive flounder, Paralichthys olivaceus. Serum concentrations of these antimicrobials were determined after oral administration of a single dosage of 60 mg/kg body weight (average 700 g). At $23{\pm}1.5^{\circ}C$, the peak serum concentrations of NA, PA and OA, which attained at 10 h, 24 h and 30 h post-dose, were 11.55, 3.79 and $1.12{\mu}g/m\ell$, respectively. At $13{\pm}1.5^{\circ}C$, the peak serum concentrations of NA, PA and OA, which attained at 10 h, 15 h and 30 h post-dose, were 6.36, 1.4 and $1.01{\mu}g/m\ell$, respectively. Better absorption of NA and PA was noted at $23{\pm}1.5^{\circ}C$ compared to $23{\pm}13^{\circ}C$. The elimination of NA from serum of olive flounder was considerably faster at $23{\pm}1.5^{\circ}C$ than at $13{\pm}1.5^{\circ}C$. However, both absorption and elimination of OA were not affected significantly by temperature. The kinetic profile of absorption, distribution and elimination of these antimicrobials in serum were analyzed by fitting to a one- and two compartment model, with WinNonlin program. In the one compartment model for NA, AUC, Tmax and Cmax at $23{\pm}1.5^{\circ}C$ were $258.26{\mu}g{\cdot}h/m\ell$, 10.67 h and $8.91{\mu}g/m\ell$, respectively. The AUC, $T_{max}$ and $C_{max}$ at $13{\pm}1.5^{\circ}C$ were $341.45 {\mu}g{\cdot}h/m\ell$, 7.72 h and $6.23{\mu}g/m\ell$, respectively. In the one compartment model for PA, AUC, $T_{max}$ and $C_{max}$ at $23{\pm}1.5^{\circ}C$ were $248.12{\mu}g{\cdot}h/m\ell$, 21.15 h and $3.09{\mu}g/m\ell$, respectively. The AUC, $T_{max}$ and $C_{max}$ at $13{\pm}1.5^{\circ}C$ were $103.89{\mu}g{\cdot}h/m\ell$, 12.89 h and $1.22{\mu}g/m\ell$, respectively. In the two compartment model for OA, AUC, $T_{max}$ and $C_{max}$ at $23{\pm}1.5^{\circ}C$ were $138.20{\mu}g{\cdot}h/m\ell$, 23.95 h and $1.06{\mu}g/m\ell$, respectively. The AUC, $T_{max}$ and $T_{max}$ at $13{\pm}1.5^{\circ}C$ were $159.10{\mu}g{\cdot}h/m\ell$, 28.03 h and $1.02{\mu}g/m\ell$, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.4
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• pp.362-370
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• 2010

In this paper, a compact RF Front-end module for Wireless Fidelity(Wi-Fi) and Worldwide Interoperability for Microwave Access(WiMAX) applications is realized by low temperature co-fired ceramic(LTCC) technology. The RF Front-end module is composed of three LTCC band-pass filters, a Film Bulk Acoustic Resonator(FBAR) filter, fully embedded matching circuits, an SPDT switch for mode selection, an SPDT switch for Tx/Rx selection, and an SP4T switch for band selection. The parasitic elements of 0.2~0.3 pF are generated by the structure of stacking in the top pad pattern for DC block capacitor of SPDT switch for mode selection. These kinds of parasitic elements break the matching characteristic, and thus, the overall electrical performance of the module is degraded. In order to compensate it, we insert a parallel lumped-element inductor on capacitor pad pattern for DC block, so that we obtain the optimized performance of the RF Front-end module. The fabricated RF front-end module has 12 layers including three inner grounds and it occupies less than $6.0mm{\times}6.0mm{\times}0.728mm$.