• The Journal of the Acoustical Society of Korea
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• v.21 no.4E
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• pp.156-163
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• 2002

We apply independent component analysis (ICA) for extracting an optimal basis to the problem of finding efficient features for representing speech signals of a given speaker The speech segments are assumed to be generated by a linear combination of the basis functions, thus the distribution of speech segments of a speaker is modeled by adapting the basis functions so that each source component is statistically independent. The learned basis functions are oriented and localized in both space and frequency, bearing a resemblance to Gabor wavelets. These features are speaker dependent characteristics and to assess their efficiency we performed speaker identification experiments and compared our results with the conventional Fourier-basis. Our results show that the proposed method is more efficient than the conventional Fourier-based features in that they can obtain a higher speaker identification rate.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.238-243
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• 1986

Distillation columns are widely used in almost every chemical plant. The use of multivariable control for such units is attractive because of the strong interactions exhibited between outputs and inputs and the desire to control simultaneously both top and bottom products. In this research design of a robust multivariable controller for distillation column was considered; output feedback controller with proportional and integral modes was designed using pole assignment. The transfer function matrix was obtained by fitting the step response realtions between single input double output pairs of variables. This matrix was then converted to linear time invariant state space model by multivariable realization technique. With the proposed multivariable proportional and integral controller applied to the process, the result of the digital computer simulation showed a good performance of asymtotic tracking. The limited experimental performance of this multivariable control was compared with the result from simulation. It was found that the proposed controller performed satisfactorily for the distillation column which separated binary mixture of methanol and water.

• The Journal of the Acoustical Society of Korea
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• v.21 no.4
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• pp.156-156
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• 2002

We apply independent component analysis (ICA) for extracting an optimal basis to the problem of finding efficient features for representing speech signals of a given speaker The speech segments are assumed to be generated by a linear combination of the basis functions, thus the distribution of speech segments of a speaker is modeled by adapting the basis functions so that each source component is statistically independent. The learned basis functions are oriented and localized in both space and frequency, bearing a resemblance to Gabor wavelets. These features are speaker dependent characteristics and to assess their efficiency we performed speaker identification experiments and compared our results with the conventional Fourier-basis. Our results show that the proposed method is more efficient than the conventional Fourier-based features in that they can obtain a higher speaker identification rate.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.165-168
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• 2015

To measure laminar burning velocity in methane/air/ethylene mixture flame, propagating centrally ignited spherical premixed flame to radial direction was measured by high-speed schlieren images with elevated pressure. In this study, The experimentally measured unstretched laminar burning velocities of methane was compared with GRI mech 3.0 to validate experimental data and choose the radius range, respectively. numerical prediction using the PREMIX code with GRI mech 3.0, USC mech II,, and Wang mech were evaluated through comparison with experimental burning velocity with consideration of extrapolation on linear/nonlinear model.

• Computers and Concrete
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• v.19 no.4
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• pp.395-404
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• 2017

In this paper, the mechanical property of CFRP, BFRP, GFRP and their hybrid FRP was experimentally studied. The elastic modulus and tensile strength of CFRP, BFRP, GFRP and their hybrid FRP were tested. The experimental results showed that the elastic modulus of hybrid FRP agreed well with the theoretical rule of mixture, which means the property of hybrid composites are linear with the volumes of the corresponding components while the tensile strength did not. The bearing capacity, peak strain, stress-strain relationship of circular concrete columns confined by CFRP, BFRP, GFRP and hybrid FRP subjected to axial compression were recorded. And the confinement effect of hybrid FRP on concrete columns was analyzed. The test results showed that the bearing capacity and ductility of concrete columns were efficiently improved through hybrid FRP confinement. A strength model and a stress-strain relationship model of hybrid FRP confined concrete columns were proposed. The proposed stress-strain model was shown to be capable of providing accurate prediction of the axial compressive strength of hybrid FRP confined concrete compared with Teng et al. (2002) model, Karbhari and Gao (1997) model and Miyachi et al. (1999) model. The modified stress-strain model was also suitable for single FRP confinement cases and it was so concise in form and didn't have piecewise fitting, which would be easy for use in structural design.

• Korean journal of food and cookery science
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• v.25 no.2
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• pp.234-242
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• 2009

This study was performed to find the optimum ratio of ingredients for the manufacture of kiwifruit jam. The experiment was designed according to the D-optimal design of RSM (response surface methodology), which included 18 experimental points with 4 replicates for three independent variables (sugar $35{\sim}60%$, pectin $0.1{\sim}1.0.%$, kiwifruit paste $0.37{\sim}0.90%$). The compositional and functional properties of the prepared products were measured, and these values were applied to mathematical models. A canonical form and trace plot showed the influence of each variable on the quality attributes of the final product mixture. By use of the F-test, viscosity, color values (L, a, b), and sensory characteristics (color) were expressed by a linear model, while the L color value and select sensory characteristics (smell, taste, overall acceptance) were also expressed by a quadratic model. The optimum formulations by the numerical and graphical methods, were similar, and with the numerical method it presented as: sugar, pectin, and barley sproutling powder at 49.7%, 0.5%, and 0.6%, respectively. The above results demonstrate the feasibility of preparing kiwifruit jam added with barley sproutling powder, and therefore, the commercialization of a kiwifruit jam marketed as a functional food is deemed possible.

• Phonetics and Speech Sciences
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• v.7 no.1
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• pp.3-10
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• 2015

In this paper, different frequency scales in cepstral feature extraction are evaluated for the text-independent speaker recognition. To this end, mel-frequency cepstral coefficients (MFCCs), linear frequency cepstral coefficients (LFCCs), and bilinear warped frequency cepstral coefficients (BWFCCs) are applied to the speaker recognition experiment. In addition, the spectro-temporal features extracted by the cepstral-time matrix (CTM) are examined as an alternative to the delta and delta-delta features. Experiments on the NIST speaker recognition evaluation (SRE) 2004 task are carried out using the Gaussian mixture model-universal background model (GMM-UBM) method and the joint factor analysis (JFA) method, both based on the ALIZE 3.0 toolkit. Experimental results using both the methods show that BWFCC with appropriate warping factor yields better performance than MFCC and LFCC. It is also shown that the feature set including the spectro-temporal information based on the CTM outperforms the conventional feature set including the delta and delta-delta features.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.3
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• pp.174-187
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• 2011

The flowed soil is able to be estimated from topographic data of before and after the debris flow. However, it is often difficult to obtain airborne LiDAR data before the debris flow area. Thus, this study tries to develop a topographic restoration method that can provide spatial distribution of flowed soil and reconstruct the topography before the debris flow using airborne LiDAR data. The topographic restoration method can express a numerical formula induced from a Gaussian mixture model after extracting the cross sections of linear or non-linear in debris flowed area. The topographic restoration method was verified by two ways using airborne LiDAR data of before and after the debris flow. First, each cross section extracted from the debris flow sites to restore the topography was compared with airborne LiDAR data of before the debris flow. Also, the topographic data produced after the topographic restoration method applied to the debris flow sites was verified by airborne LiDAR DEM. Verifying the results of the topographic restoration method, overall fitting accuracy showed high accuracy close to 0.5m.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.7
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• pp.1013-1018
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• 2014

In this study, we developed kinetic models to predict the growth of pathogenic Escherichia coli on cheeses during storage at constant and changing temperatures. A five-strain mixture of pathogenic E. coli was inoculated onto natural cheeses (Brie and Camembert) and processed cheeses (sliced Mozzarella and sliced Cheddar) at 3 to 4 log CFU/g. The inoculated cheeses were stored at 4, 10, 15, 25, and $30^{\circ}C$ for 1 to 320 h, with a different storage time being used for each temperature. Total bacteria and E. coli cells were enumerated on tryptic soy agar and MacConkey sorbitol agar, respectively. E. coli growth data were fitted to the Baranyi model to calculate the maximum specific growth rate (${\mu}_{max}$; log CFU/g/h), lag phase duration (LPD; h), lower asymptote (log CFU/g), and upper asymptote (log CFU/g). The kinetic parameters were then analyzed as a function of storage temperature, using the square root model, polynomial equation, and linear equation. A dynamic model was also developed for varying temperature. The model performance was evaluated against observed data, and the root mean square error (RMSE) was calculated. At $4^{\circ}C$, E. coli cell growth was not observed on any cheese. However, E. coli growth was observed at $10{\circ}C$ to $30^{\circ}C$C with a ${\mu}_{max}$ of 0.01 to 1.03 log CFU/g/h, depending on the cheese. The ${\mu}_{max}$ values increased as temperature increased, while LPD values decreased, and ${\mu}_{max}$ and LPD values were different among the four types of cheese. The developed models showed adequate performance (RMSE = 0.176-0.337), indicating that these models should be useful for describing the growth kinetics of E. coli on various cheeses.

• Journal of Pharmaceutical Investigation
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• v.35 no.4
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• pp.279-285
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• 2005

Ground CS-891 (N-[1-(4-methoxyphenyl)-1-methylethyl]-3-oxo-4-aza-5a-androst-1-ene-$17{\beta}$-carboxamide) of poorly water soluble drug was obtained using a Heiko Seisakusho model TI-100 vibration mill, and samples with different crystallinity were prepared at mixture ratios of 10:0, 7:3, 5:5, 3:7 and 0:10 (intact;ground CS-891). Physicochemical characterizations were obtained using qualitative and quantitative X-ray diffractometry, different scanning calorimetry (DSC), scanning electron microscopy (SEM), Quantasorb surface area analyzer, and controlled atmosphere microbalance. With increase of amorphous CS-891 in mixture ratios, the intensities of X-ray diffraction peaks of crystalline CS-891 were decreased, whereas surface area, water absorption, and exothermic peaks in DSC were increased. The apparent solubility of ground CS-891 was $4.4\;{\mu}g/ml$ and the solubility of intact CS-891 was $3.1\;{\mu}g/ml$ at $37{\pm}1^{\circ}C$. The apparent precipitation rates of CS-891 in a supersaturated solution during the solubility test were increased with an increase of amorphous CS-891, and a crystalline form of CS-891 transformed from amorphous CS-891 after the solubility test was found by X-ray diffraction analysis, DSC and SEM. The dissolution profiles of CS-891 with different crystallinity at $37{\pm}1^{\circ}C$ by the USP paddle method were investigated, and the apparent dissolution rate constant of ground CS-891 was about 5.9-fold higher than that of intact CS-891. A linear relationships between the crystallinity of CS-891 and the apparent dissolution rate constant (r>0.96) were obtained.