• Journal of Biomedical Engineering Research
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• v.39 no.2
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• pp.69-79
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• 2018

The present study proposes an algorithm that can discriminate between normal subjects and paroxysmal atrial fibrillation (PAF) patients, which is conducted using electrocardiogram (ECG) without PAF events. For this, time-domain features and random forest classifier are used. Time-domain features are obtained from Poincare plot, Lorenz plot of ${\delta}RR$ interval, and morphology analysis. Afterward, three features are selected in total through feature selection. PAF patients and normal subjects are classified using random forest. The classification result showed that sensitivity and specificity were 81.82% and 95.24% respectively, the positive predictive value and negative predictive value were 96.43% and 76.92% respectively, and accuracy was 87.04%. The proposed algorithm had an advantage in terms of the computation requirement compared to existing algorithm, so it has suggested applicability in the more efficient prediction of PAF.

• Journal of Ceramic Processing Research
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• v.13 no.spc2
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• pp.163-165
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• 2012

Impedance spectroscopy informs electrical properties of materials as accumulated charges, contact status between electrode and organic materials. We carried out impedance spectroscopy of organic light-emitting diodes as ITO/Alq3(60 nm)/Al on temperatures from 10 K to 300 K. The result described Z'-Z" plot, cole-cole plot and dielectric relaxation time τ. Z'-Z" plot means that real and imaginary part of materials in organic and electrode by frequencies and temperature. Z' as real part of impedance by applied frequency depending on temperature shows the plateau in low frequency region as Rs+ Rp and over 100 kHz in high frequency region as Rs. Cole-cole plot shows resistance of materials in equivalent circuit of the device by temperatures. And equivalent circuit and dielectric relaxation could be accomplished by using the complex impedance analysis.

• Journal of computational fluids engineering
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• v.9 no.2
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• pp.1-10
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• 2004

In the present study, a post-processing program is developed for 3D data visualization and analysis. Because the graphical user interface(GUI) of the program is based on Qt-library while all the graphic rendering is performed with OpenGL library, the program runs on not only MS Windows but also UNU and Linux systems without modifying source code. The structure of the program is designed according to the object-oriented programming(OOP) concept so that it has extensibility, reusability, and easiness compared to those by procedural programming. The program is organized as modules by classes, and these classes are made to function through inheritance and cooperation which is an important and valuable concept of object-oriented programming. The major functions realized so far which include mesh plot, contour plot, vector plot, streamline plot, and boundary plot are demonstrated and the relevant algorithms are described.

• Communications for Statistical Applications and Methods
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• v.11 no.2
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• pp.345-353
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• 2004

Graphical methods for the specification of the curvature as a function of two predictors are animated to see the effect of an added variable to the model. Through a 3D animated plot it might be difficult to find a sequence of interpretable plots. But examples demonstrate that useful information can be obtained by using rotation technique in 3D plot. Besides 3D plots, an example of 2D animated plot applied to the case of high correlation between predictors and an added predictor is also given. It implies that speed of the convergence to a certain image in a dynamic plot may be understood as an influence of collinearity.

• Communications for Statistical Applications and Methods
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• v.18 no.5
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• pp.637-644
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• 2011

Partially ranked data refers to the situation in which there are p distinct objects; however each judge specifies only first s (s < p) choices. The group theoretic formulation for partially ranked data analysis was set up by Critchlow (1985). We propose a graphical method for partially ranked data by quantifying objects and judges. In a plot for judges, the interpoint distances can be interpreted as Spearman or Kendall distances between two rankings given by respective judges. Similarly, we also construct a plot for objects with a sensible relationship to the previous plot for judges. This study extends the Han and Huh (1995) quantification method of fully ranked data using Gabriel's (1971) biplot technique for multivariate data matrix.

• International Journal of Reliability and Applications
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• v.14 no.2
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• pp.107-114
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• 2013

Modelling of failures is an important element of reliability modelling. Empirical modelling approach suitable for complex item is explored in this paper. First step of the empirical modelling approach is to plot hazard function, density function, Weibull probability plot as well as cumulative intensity function to see which model fits best for the given data. Next step of the empirical modelling approach is select appropriate model for the data and fit the parametric model accordingly and estimate the parameters.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.6
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• pp.731-735
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• 2015

The effects of liquid pig manure (LPM) on the yield and nutrient supply of green manure crops, such as hairy vetch alone and hairy vetch + rye mixture, were investigated. We used three treatments: no-fertilizer (NF); LPM, $4.0t10a^{-1}$ ($N-P_2O_5-K_2O=4.0-0.024-4.0kg10a^{-1}$); and chemical fertilizer (CF; $N-P_2O_5-K_2O=4.0-0-4.0kg10a^{-1}$). The green manure crops, namely, Vicia villosa Roth. (hairy vetch) and Secale cereale L. (rye). were sown on March 11 and harvested on June 24, 2014. Yield of green manure crops significantly increased in hairy vetch + rye mixture plot compared with the hairy vetch alone plot. In hairy vetch alone plot, yield of green manure crops was increased by application of LPM and CF, but there were no significant differences. Yield of green manure crops in hairy vetch + rye fresh mixture plot significantly increased by the LPM and CF treatments, but no difference was noted between the LPM and CF treatments. Nitrogen supply by the green manure crops was higher in hairy vetch + rye mixture plot than hairy vetch alone plot. However, there was no significant difference. Phosphorus and potassium supply significantly increased in hairy vetch + rye mixture plot compared with hairy vetch alone plot. By treating LPM and CF, the nitrogen, phosphorus and potassium supply were higher than those in no fertilizer. In conclusion, LPM could replace CF. When planting green manure crops, the hairy vetch + rye mixture was more effective than hairy vetch alone to effectively use green manure crops.

• Journal of Korean Society on Water Environment
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• v.32 no.1
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• pp.108-114
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• 2016

Sediment-laden water leads to water quality degradation in streams; therefore, best management practices must be implemented in the source area to control nonpoint source pollution. Field monitoring was implemented to measure precipitation, direct runoff, and sediment concentrations at a control plot and straw-applied plot to examine the effect on sediment reduction in this study. A hydrology model, which employs Curve Number (CN) to estimate direct runoff and the Universal Soil Loss Equation to estimate soil loss, was selected. Twenty-five storm events from October 2010 to July 2012 were observed at the control plot, and 14 storm events from April 2011 to July 2011 at the straw-applied plot. CN was calibrated for direct runoff, and the Nash-Sutcliffe efficiency and coefficient of determination were 0.66 and 0.68 at the control plot. Direct runoff at the straw-applied plot was calibrated using the percentage direct runoff reduction. The estimated reduction in sediment load by direct runoff reduction calibration alone was acceptable. Therefore, direct runoff-sediment load behaviors in a hydrology model should be considered to estimate sediment load and the reduction thereof.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.271-272
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• 2006

This paper presented a new experimental gain tuning technique for a Multi-Axis Servo System. First, the investigation for proportional gain of velocity control loop by using a Dynamic Signal Analyzer (DSA) was performed. Using the FUNCTION characteristic of DSA based on the Bode plot, the Bode plot of open loop transfer function was obtained. In turn, the integral gain of a servo controller can be found out by using the Integration time constant extracted from the Bode plot of open loop transfer function. In the meanwhile, the positional gain of the servo controller has been obtained by using the Bode plot of the closed loop transfer function. We have also proposed the technique to find out an optimal parameter of a notch filter, which has a great influence on vibration reduction, by using the damping factor extracted from the Bode plot of closed loop transfer function.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.2
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• pp.162-166
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• 2014

This study was conducted to evaluate effects of planting densities ($60{\times}5cm$, $60{\times}10cm$, $60{\times}15cm$) and PE mulching (polyethylene film mulching, non- mulching) on growth and yield of foxtail millet in drained paddy field for 2 years. In PE plots, culm length, culm diameter and fresh weight were higher than control plot. Additionally, spike length, seed weight per hill and thousand seed weight were also higher in PE plot. The yield of foxtail millet were increased with 104% and 112% at PE plot. Culm diameter was highest at $60{\times}15cm$ plot with 8.90 and 8.06 mm, however, culm length was highest at $60{\times}5cm$ plot with 130, 142 cm in $1^{st}$ and $2^{nd}$, respectively. Plant height was higher by the increase of planting density. As plant density decreased, that spike length and seed weight per hill were increased. Yield of planting density were highest at $60{\times}10cm$ plot $298kg{\cdot}10a^{-1}$, $436kg{\cdot}10a^{-1}$ yearly, respectively that it were in order of $60{\times}10cm$ plot > $60{\times}5cm$ plot > $60{\times}15cm$ plot.