• The Journal of the Acoustical Society of Korea
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• 제18권2E호
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• pp.31-38
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• 1999

This paper focuses on extracting formants from transfer function, derived from linear prediction analysis of speech signal. The second derivative of the log magnitude spectrum of the transfer function, the first and third derivatives of the phase spectrum of the transfer function in the z-plane are discussed. Their resolutions of detecting formants are analyzed and some comparisons are given. Theoretical analyses and experimental results show that the third derivative of the phase spectrum decays more rapidly around the formant locations than the first derivative of the phase spectrum and the second derivative of the log magnitude spectrum. Compared with the second derivative of the log spectrum and the first derivative of the phase spectrum, the third derivative of the phase spectrum has higher resolution in frequency domain and provides more accurate formant extraction.

• 호남수학학술지
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• 제37권4호
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• pp.559-567
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• 2015

This paper gives the expression of dual quaternions and provides differential operators in dual quaternions. The paper also represents the derivative of dual quaternion-valued functions by using a corresponding Cauchy-Riemann system in dual quaternions.

• Journal of applied mathematics & informatics
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• 제28권3_4호
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• pp.913-921
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• 2010

The derivative influence measure is adapted to the Cholesky decomposition of a covariance matrix. Formulas for the derivative influence of observations on the Cholesky root and the inverse Cholesky root of a sample covariance matrix are derived. It is easy to implement this influence diagnostic method for practical use. A numerical example is given for illustration.

• Nonlinear Functional Analysis and Applications
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• 제28권1호
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• pp.287-294
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• 2023

The goal of this paper is to extend some inequalities of Bernstein as well as Turán type to polar derivative of a polynomial.

• 약학회지
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• 제30권4호
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• pp.185-192
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• 1986

Authors developed the computer application program (language: APPLE SOFT BASIC) for derivative spectrophotometry. By means of this program, derivative of spectral absorbance with respect to wavelength is recorded versus wavelength. To try this program in connection with spectrophotometer system, the authors have done the simultaneous quantitation of pyridoxine center dot HCl and nicotinamide in the mixture, and the result was compared with that of absorbance method.

• 한국수학교육학회:학술대회논문집
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• 한국수학교육학회 2010년도 제44회 전국수학교육연구대회
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• pp.249-259
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• 2010

This report is intended to document beliefs that engineers working as senior high school teachers have in Mexico. Documents come from the analysis of answers provided for two tasks contained in a questionnaire: one of them is marking statements as true or false in relation to the derivative function; the second one is about solving different problems: calculation of derivative of piecewise functions and the calculation of maximum and minimum of a polynomial function. Results show the strengths, quasi-logical relations and grouping which are verified in their system of beliefs and knowledge.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제22권1호
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• pp.65-74
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• 2015

In this paper, we provide the notions of dual quaternions and their algebraic properties based on matrices. From quaternion analysis, we give the concept of a derivative of functions and and obtain a dual quaternion Cauchy-Riemann system that are equivalent. Also, we research properties of a regular function with values in dual quaternions and relations derivative with a regular function in dual quaternions.

• 한국의류학회지
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• 제24권7호
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• pp.1081-1087
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• 2000

Gromwell colorants were extracted with methanol and dried. Four fractions were obtained by silica gel adsorption column chromatography using step-wise elution method. Relative ratio of four fraction is 1.00:0.07:0.22:0.30(Fl:F2:F3:F4) and gromwell colorants mainly consist of Fl, F3 and F4. IR analysis shows that each fraction has similar structure. Main component of gromwell extracts is acetyl derivative of naphthoquinone, and the rest are isobutyl derivative and isovaleryl derivative etc., in order. Gromwell colorants exhibit relatively good affinity to protein and polyamide fibers, but low affinity to cellulose and regenerated cellulose fibers.

• Journal of Biosystems Engineering
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• 제22권2호
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• pp.247-255
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• 1997

This study was conducted to develop regression models predicting sugar and acid contents in intact fruits nondestructively by using the second derivative of absorbance spectrum measured with a spectrophotometer wavelength range of 400nm to 2, 400nm. The correlation analysis was made in wavelength range of 600nm to 1, 100nm and 600nm to 2, 400nm respectively, in order to examine the feasibility of using a real time spectrophotometer, which covers the former range, in predicting sugar and acid contents. The second derivative data of the spectrum were obtained by varying smoothing size and derivative size of the original absorbance spectrum. SAS statistical package program was used for the regression analysis. The sugar contents of Fuji apple, Shingo pear md Yumyung peach could be predicted with SEPs of 0.40, 1.17 and 0.77 respectively, in the spectrum range of 600 to 1, 100nm. The highest correlation coefficient of the titratible acidity of apple was -0.45 at 2, 346nm and regression models indicated determination coefficient less than 0.47.

• 약학회지
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• 제41권5호
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• pp.571-574
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• 1997

We have synthesized acetylsalicylic acid derivative of eugenol. And also, physico-chemical properties and analysis on this compound were examined. The correlation coefficient of the calibration curve in methanol solution was 0.9998. The hair growth stimulation of eugenol derivative on the hair of black mouse (C57BL/6), was also carried out using Implant method. When its ethanol solution was administered to the black mouse by route of skin, eugenol derivative promoted the growth of hair.