• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.5-6
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• 2014

For estimating compressive strength of concrete, non-destructive test has conducted generally. It used experimental equation to calculate compressive strength from construction. This study investigated experiment to apply non-destructive test, based on fresh property, compressive strength and ultrasonic pulse velocity of high performance concrete. And it conducted to compare various proposed equation.

• Journal of information and communication convergence engineering
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• v.2 no.3
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• pp.187-192
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• 2004

A method using two dimension Haar functions approximation for solving the problem of a partial differential equation and estimating the parameters of a non-linear distributed parameter system (DPS) is presented. The applications of orthogonal functions, including Haar functions, and their transforms have been given much attention in system control and communication engineering field since 1970's. The Haar functions set forms a complete set of orthogonal rectangular functions similar in several respects to the Walsh functions. The algorithm adopted in this paper is that of estimating the parameters of non-linear DPS by converting and transforming a partial differential equation into a simple algebraic equation. Two dimension Haar functions approximation method is introduced newly to represent and solve a partial differential equation. The proposed method is supported by numerical examples for demonstration the fast, convenient capabilities of the method.

• Communications for Statistical Applications and Methods
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• v.10 no.2
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• pp.341-352
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• 2003

Collecting data through experiment, the observers are an import source of measurement error and the inference on the measure of agreement, say kappa, is necessary. The models commonly used are complicated general mixture model, which have many nuisance parameters. Orthogonalization of parameters reduce the effect of nuisance parameter. Orthogonalization of estimating function gives the same effect as the parameter orthogonalization. In this study, the method for orthogonalization of estimating equation is studied and applied to the Beta-binomial model to examine the properties of the estimate of kappa. As a result, the likelihood function is insensitive to the change of the nuisance parameter and bias is smaller than the result of m.1.e. when kappa has extreme values

• Journal of Environmental Science International
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• v.24 no.4
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• pp.461-470
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• 2015

As hydrogeologic parameters such as hydraulic conductivity and specific yield are estimated by aquifer test, these are dependent on specific points at which field test was conducted. To overcome these site-specific limitations, a method of estimating transmissivity of aquifer using distribution features for parameters in Water table fluctuation model is newly suggested. Distribution features in reaction factor, specific yield and transmissivity having the function of pore space in aquifer are used to derive empirical equation for estimating transmissivity. From the result for applying the equation for 10 groundwater stations in Northeast Jeju Island, this equation is available for estimating transmissivity compared to the value estimated by existing equations. The estimated transmissivity ranged from 14.2 to $3,716.9m^2/day$, and its average was $821.8m^2/day$.

• Journal of Industrial Technology
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• v.36
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• pp.57-63
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• 2016

In this study characteristics of debris flow landslide were investigated on the focus of debris flow disaster occurred by heavy rainfall in 2013 at Goeun-ri around Kaeryoung Mt. in Chuncheon-si. Appropriate method for estimating scale of debris flow was investigated by comparing those values from soil loss by Universal Soil Loss Equation, debris flow yield rate obtained by field survey of investigating debris flow path from initiation and erosion to deposition and other methods. As results of this study, it might be an opportunity of contributing to construct the data base for determining the size of erosion control facilities in future.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.355-358
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• 2003

To estimate the residual stresses in the thin film and surface coatings, combined method based on nanoindentation and finite element (FE) analysis was developed. A simple equation for estimating the residual stress was composed of the hardness and the parameters which can be driven from the nanoindentation loading and unloading behaviors. FE analysis on the nanoindentation procedure under the various residual stress levels was performed to determine the parameters that included in the equation. The equation showed a good coincidence between the estimated residual stresses and those for the FE analysis. Thus the proposed method was considered as a useful method for estimating the residual stresses in the thin film without stress free specimen.

• Journal of the Korean Statistical Society
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• v.35 no.2
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• pp.213-224
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• 2006

We investigate the influence of subjects or observations on regression coefficients of generalized estimating equations using the influence function and the derivative influence measures. The influence function for regression coefficients is derived and its sample versions are used for influence analysis. The derivative influence measures under certain perturbation schemes are derived. It can be seen that the influence function method and the derivative influence measures yield the same influence information. An illustrative example in longitudinal data analysis is given and we compare the results provided by the influence function method and the derivative influence measures.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.3
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• pp.230-234
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• 2009

As concrete ages, the surrounding environment is expected to have growing influences on the concrete. As all the impacts of the environment cannot be considered in the strength-estimating model of a nondestructive concrete test, the increase in concrete age leads to growing uncertainty in the strength-estimating model. Therefore, the variation of the model error increases. It is necessary to include those impacts in the probability model of concrete strength attained from the nondestructive tests so as to build a more accurate reliability model for structural performance evaluation. This paper reviews and categorizes the existing strength-estimating statistical models of nondestructive concrete test, and suggests a new form of the strength-estimating statistical models to properly reflect the model uncertainty due to aging of the concrete. This new form of the statistical models will lay foundation for more accurate structural performance evaluation.

• Journal of the Korean Institute of Gas
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• v.20 no.2
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• pp.49-57
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• 2016

Aqueous ammonia is widely used in household cleaners, fertilizers and denitrification process. It is usually treated in concentrations from 10 % to 30 %, and release accidents have occurred frequently. In this study, we developed a simplified estimating method and equation to calculate threat zone easily in case of emergency due to release accident of aqueous ammonia. We calculated the consequence distance for toxic endpoints of aqueous ammonia(concentration 10 % ~ 30 %) at different puddle areas($1m^2{\sim}500m^2$) using the ALOHA program. Based on the result, we analyzed the relationship between concentration and puddle area with the threat zone and created the equation.

• Journal of Electrochemical Science and Technology
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• v.7 no.4
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• pp.293-297
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• 2016

Here we propose a new equation by which we can estimate the baseline for measuring the peak current of the reverse curve in a cyclic voltammogram. A similar equation already exists, but it is a linear algebraic equation that over-simplifies the voltammetric curve and may cause unpredictable errors when calculating the baseline. In our study, we find a quadratic algebraic equation that acceptably reflects the complexity included in a voltammetric curve. The equation is obtained from a laborious numerical analysis of cyclic voltammetry simulations using the finite element method, and not from the closed form of the mathematical equation. This equation is utilized to provide a virtual baseline current for the reverse peak current. We compare the results obtained using the old linear and new quadratic equations with the theoretical values in terms of errors to ascertain the degree to which accuracy is improved by the new equation. Finally, the equations are applied to practical cyclic voltammograms of ferricyanide in order to confirm the improved accuracy.