• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.217-221
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• 2003

Variation of decision variables for optimal remediation using the pump-and-treat method is examined to estimate the effect of the degree of concentration constraint. Simulation-optimization method using genetic algorithm is applied to minimize the total pumping volume. In total volume minimization strategy, the remediation time increases rapidly prior to significant increase in pumping rates. When the concentration constraint is set severer, the more wells are required and the well on the down-gradient direction from the plume hot-spot gives more efficient remediation performance than that on the hot-spot position. These results show that the more profitable strategy for remediation can be achieved by increasing the required remediation time than raising the pumping rate until the time reaches a certain limitation level. So, the remediation time has to be considered as one of the essential decision variables fer optimal remediation design.

• Korean Journal of Clinical Pharmacy
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• v.26 no.2
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• pp.150-162
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• 2016

Objective: First-in-human dose estimation is an essential approach for successful clinical trials for drug development. In this study, we systematically compared first-in-human dose and human pharmacokinetic parameter estimation approaches. Methods: First-in-human dose estimation approaches divided into similar drug comparison approaches, regulatory guidance based approaches, and pharmacokinetic based approaches. Human clearance, volume of distribution and bioavailability were classified for human pharmacokinetic parameter estimation approaches. Results: Similar drug comparison approaches is simple and appropriate me-too drug. Regulatory guidance based approaches is recommended from US Food and Drug Administration (FDA) and European Medicines Agency (EMA) regarding no-observed-adverse-effect level (NOAEL) or minimum anticipated biological effect level (MABEL). Pharmacokinetic based approaches are 8 approaches for human clearance estimation, 5 approaches for human volume of distribution, and 4 approaches for human bioavailability. Conclusion: This study introduced and compared all methods for first-in-human dose estimation. It would be useful practically to estimate first-in-human dose for drug development.

• Geomechanics and Engineering
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• v.16 no.2
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• pp.159-168
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• 2018

In this study, a real-time grouting management system based on the clogging theory was established to manage injection procedure in real time. This system is capable of estimating hydraulic permeability with the passage of time as the grout permeates through the ground, and therefore, capable of estimating real time injection distance and flow rate. By adopting the Controlled Injection Pressure (CoIP) model, it was feasible to predict the grout permeation status with the elapse of time by consecutively updating the hydraulic gradient and flow rate estimated from a clogging-induced alteration of pore volume. Moreover, a method to estimate the volume of the fractured gap according to the reduction in injection pressure was proposed. The validity of the proposed system was successfully established by comparing the estimated values with the measured field data.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.6
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• pp.713-721
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• 1999

A composite plastic, where long metallic fibers are used as filling materials, is transformed from nonconducting to conducting medium as the volume fraction of filling metallic fibers is increased from zero : such drastic change in property is called the percolation. It is desired both for practical and theoretical purposes to understand the physics underlying the percolation and to estimate the percolation threshold that is defined by the minimum volume fraction of the metallic fibers for which the percolation occurs. In this study, percolation thresholds are calculated by Monte Carlo Computer simulation. Both lattice and continuum spaces are considered and detailed microstructures of metallic fibers are modelled as rigid and flexible bodies for both model spaces. Simulations are carried out for wide range of aspect ratios and discussions are given.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.19-24
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• 2000

The objective of this study is to develope a computer simulation model and estimate theoretically the transient performance characteristics of heat exchangers in an automotive air-conditioning system. To do that, the mathematical modelling of heat exchangers, such as evaporator and condenser, is presented first of all. For detail calculation, evaporator and condenser are divided into many sub-sections. Each sub-section is an elemental volume for transient modelling. The elemental volume is assumed to consist of three components, refrigerant, tube with fin, and air, and various properties including temperatures of three components are determined step along sub-sections. The properties of refrigerant R134a and air are calculated directly in the program. The heat transfer coefficients and pressure drop in single or two phase are also calculated by suitable empirical correlations. The overall tendencies of the simulation results were agreed well with those of actual situation.

• Journal of Korea Water Resources Association
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• v.33 no.1
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• pp.31-38
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• 2000

Relationships between hydrologic variables are often nonlinear. Usually the functional form of such a relationship is not known a priori. A multivariate, nonparametric regression methodology is provided here for approximating the underlying regression function using locally weighted polynomials. Locally weighted polynomials consider the approximation of the target function through a Taylor series expansion of the function in the neighborhood of the point of estimate. The utility of this nonparametric regression approach is demonstrated through an application to nonparametric short term forecasts of the biweekly Great Salt Lake volume.volume.

• The Journal of Asian Finance, Economics and Business
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• v.3 no.2
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• pp.33-39
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• 2016

This study empirically evaluates the impact of exchange rate volatility, foreign direct investment, terms of trade, inflation, and industrial production and foreign exchange reserves on Pakistani trade volume over the period of 1975-2010 using quarterly data set. The study employs financial econometrics methods such as Augmented Dickey Fuller (ADF) test GARCH (1, 1) technique and Almon Polynomial Distributed Lag (APDL) models to estimate the relationship of variables. Findings of the study are in accordance with theoretical relationships presented by Clark, Tamirisa, Wei, Sadikov, & Zeng (2004), McKenzie (1999), Dellas & Zilberfarb (1993) and Côté (1994). These findings are also in accordance with the empirical studies which support positive relationship of exchange rate volatility and exports presented by Hsu & Chiang (2011), Chit (2008), Feenstra & Kendall (1991), Esquivel & Larraín (2002) and Onafowora & Owoye (2008). Findings of the study in terms of imports are supported by the studies such as Lee (1999), Alam & Ahmad (2011) and Arize (1998). The study also recommends some very important policy prescriptions.

• Korean Journal of Veterinary Research
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• v.47 no.2
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• pp.259-263
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• 2007

The choice of input distribution in quantitative risk assessments modeling is of great importance to get unbiased overall estimates, although it is difficult to characterize them in situations where data available are too sparse or small. The present study is particularly concerned with accommodation of uncertainties commonly encountered in the practice of modeling. The authors applied parametric and non-parametric bootstrap simulation methods which consist of re-sampling with replacement, in together with the classical Student-t statistics based on the normal distribution. The implications of these methods were demonstrated through an empirical analysis of trade volume from the amount of chicken and pork meat imported to Korea during the period of 1998-2005. The results of bootstrap method were comparable to the classical techniques, indicating that bootstrap can be an alternative approach in a specific context of trade volume. We also illustrated on what extent the bias corrected and accelerated non-parametric bootstrap method produces different estimate of interest, as compared by non-parametric bootstrap method.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.1
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• pp.207-216
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• 1997

We developed the durability estimation and design systems to minimize the volume, considering the durability, efficiency, and design requirements of worm gears. That is, we consider each kind of factors affecting on durability on the basis of AGMA Standard for the cylindrical and double-enveloping worm gears. We also estimate input power on the basis of wear and durability, bending strength and deflection of worm shaft, and we developed the durability estimation and design systems of power transmission worm gears introducing the optimal design method on the personal computer to be easily used in field. Also, we developed a method which converts the design variables obtained from the optimal design method to integer values(number of worm threads, number of worm threads, number of worm wheel teeth, etc.,) to be used in real design and production. The developed durability estimation and design method can be easily applied to the design of worm gears used as power transmission devices in machineries and is expected to be used for weight minimization of worm gear unit.

• Journal of electromagnetic engineering and science
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• v.14 no.4
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• pp.336-341
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• 2014

Dosimetry of radiating electromagnetic wave from mobile devices to human body has been evaluated by measuring Specific Absorption Rate (SAR). Usual SAR measurement system scans the volume by robot arm to evaluate RF power absorption to human body from wireless devices. It is possible to fast estimate the volume SAR by software deleting robot moving time with the 2D surface SAR data acquired by arrayed probes. This paper shows the principle of fast SAR measurement and the measured data comparison between the fast SAR system and the robot scanning system. Data of the fast SAR is well corresponding with data of robot scanning SAR within ${\pm}3$ dB, and its dynamic range covers from 10 mW/kg to 30 W/kg with 4.8 mm probe diameter.