• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.416-419
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• 2001

In this paper a new approach to estimate scaling factors of fuzzy controllers such as the fuzzy PID controller and the fuzzy PD controller is presented. The performance of the fuzzy controller is sensitive to the variety of scaling factors[1]. The desist procedure dwells on the use of evolutionary computing(a genetic algorithm) and estimation algorithm for dynamic systems (the inverted pendulum). The tuning of the scaling factors of the fuzzy controller is essential to the entire optimization process. And then we estimate scaling factors of the fuzzy controller by means of two types of estimation algorithms such as Neuro-Fuzzy model, and regression polynomial [7]. This method can be applied to the nonlinear system as the inverted pendulum. Numerical studies are presented and a detailed comparative analysis is also included.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.671-677
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• 1996

This paper proposes a study on the effects of motion errors for acceleration/ deceleration types. The proposed motion errors are consisted of two errors : one due to transient response of servomechanism and the other due to gain mismatching of positioning servo motor. They are derived from using laplace transformation for the block diagram of general purpose feed drive system. In order to minimize them, the paper proposes second order polynomial regression model by using orthogonal array method which describes one of experimental methodolgies. The validity and reliability of the study was veri lied on a vertical machining center equipped with FANUC 0MC through a series of experiments and analyses.

• Archives of Pharmacal Research
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• v.19 no.3
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• pp.183-190
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• 1996

There are a wide variety of semi-solid ointments used for healing the skin diseases, whose therapeutic and skin penetration abililties may greatly differ from one another depending on the compositions of ointment vehicles. A computer optimization technique was applied to obtain the optimum formula of o/w type ointment giving the in vitro maximum absorption rate through hairless rat skin membrane. Some of the formulations were selected to find out a relationship between skin penetration of ointment and its Theological characteristics. The experimental value of absorption rate obtained from the ointment by optimum formula agreed well with the theoretical value obtained from a polynomial regression analysis, Three kinds of ointments selected among 15 formulations were obtained with a concentric cylinder type rheometer (Model; Rheolab SM-HM Physica, Germany) at 20, 30, 40 and $50^{\circ}C$ for rheograms of rhelolgical properties of o/w type ointments. As the temperature was raised, all products showed a decrease in both shear stress and yield values. The higher skin penetration, the lower shear stress showed.

• Journal of the Korean Society of Safety
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• v.8 no.4
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• pp.183-188
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• 1993

Anthropometric characteristics and considerations of sex differences are essential for the correct design of ergonomic work spaces. This paper is concerned with longitudinal study on the physical growth in Korean youth. Three hundred eighty-seven subjects were selected from third year students of high schools, and their records on physical examination during the last twelve years were surveyed by longitudinal method. For boys and girls, this study investigated the anthropometric characteristics of physical structure and the shape of physical growth. The result showed that the physical growth spurt of girl occurred earlier than that of boy. Also, by regression analysis, the third-order polynomial function was suitable for the growth curves of stature and weight, and there were significant sex differences in the fitted curves.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.4
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• pp.94-101
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• 2003

Recently, miniaturization and weight reduction is getting more attention due to various benefits in automotive components design. It is a trend that the design of experiment(DOE) and statical design method are frequently used for optimization. In this research, the safety of lower control arm is evaluated according to its material change form S45C to A16061 for the reduction of arm's weight. The variance analysis on the basis of structure analysis and DOE is applied to the lower control m. We have proposed a statistical design model to evaluate the effect of structural modification by performing the practical multi-objective optimization considering mass, stress and deflection.

• Journal of Welding and Joining
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• v.29 no.6
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• pp.82-87
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• 2011

In this study, we conducted laser welding by using remote scanner that is 5J32 aluminum alloy to observe the mechanical properties and optimize welding process parameters. As the control factors, laser incident angle, laser power and welding speed were set and as the result of weldablility, tensile shear tests were performed. ANOVA (Analysis of Variation) was also carried out to identify the influence of process variables on tensile shear strength. Strength estimation models were suggested using regression alnalysis and 2nd order polynomial model had the best estimation performance. In addition optimal welding condition was determined in terms with wedalility and productivity using objective function and fitness function. Final optimized welding condition was laser power was 4 kW, and welding speed was 4.6 m/min.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.9
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• pp.127-134
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• 2004

It is difficult to have the existing structural optimization using coupled field analysis from CFD to structure analysis when the structure is influenced of fluid. Therefore in an initial model of this study after doing parameter design from the background of shape using topology optimization. and it is making a approximation formula using by the CFD-structure coupled-field analysis and design of experiment. By using this result, we conducted multi-objective optimization. We could confirm efficiency of stochastic method applicable in the scene of structure reliability design to be needed multi-objective optimization. And we presented a way of design that could overcome the time and space restriction in structural design such as the butterfly valve with the less experiment.

• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.299-304
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• 2013

A 17-run Box-Behnken design was used to optimize the synthesis conditions of a monolithic sorbent. The effects of the amount of monomer (mL), crosslink (mL) and porogen (mL) were investigated. The experimental data were fitted to a second-order polynomial equation by the multiple regression analysis and examined using statistical methods. The adjusted coefficient of determination ($R^2$) of the model was 0.9915. The probability value (p < 0.0001) demonstrated a high significance for the regression model. A mean amount of polymer as 2120.15 mg was produced under the following optimum synthesis conditions: the optimized volumes of monomer, crosslink and porogen are 0.30, 1.40, and 1.47 mL, respectively. This was in good agreement with the predicted model value.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.5
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• pp.25-34
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• 2008

By comparing two images, which are captured with the same scene at different time, we can detect a set of outliers, such as occluding objects due to moving vehicles. To reduce the influence from the different intensity properties of the images, an intensity compensation scheme, which is based on the polynomial regression model, is employed. For an accurate detection of outliers alleviating the influence from a set of outliers, a simple technique that reruns the regression is employed. In this paper, an algorithm that iteratively reruns the regression is theoretically analyzed by observing the convergence property of the estimates of the noise variance. Using a correction constant for the estimate of the noise variance is proposed. The correction enables the detection algorithm robust to the choice of thresholds for selecting outliers. Numerical analysis using both synthetic and Teal images are also shown in this paper to show the robust performance of the detection algorithm.

• Korean Journal of Weed Science
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• v.4 no.1
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• pp.88-95
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• 1984

The study was intended to analyze the interaction effects of paraquat and oxytluorfen as an orchard herbicide-mixture. Data were prepared from the former report of authors. The algebraic expression for the actions of paraquat and oxyfluorfen on the control percentages of peach orchard weeds, and their interactions were determined from the multiple regression polynomial and plotted in three-dimensional graphs. As a result of treatments by combination of paraquat and oxyfluorfen on the field which was dominated by perennial weeds, the most effective interactions were detected at combination rates of $245\;gHa^{-1}$ paraquat and $470-705\;gHa^{-1}$ oxyfluorfen. However, to develope the long-term weeding-efficacies, the combination rates of paraquat are expected to raise up to $500-700\;gHa^{-1}$, and oxyfluorfen to fit at lower limits of rates, respectively.