• Korean Journal of Optics and Photonics
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• v.9 no.4
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• pp.245-250
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• 1998

A new computational algorithm is presented for the peak point detection of white light interferograms. Assuming the visibility function of white light interferograms as a quadratic polynomial, the peak point is searched so as to minimize the error sum between the measured intensity data and the analytical intensity. As compared with other existing algorithms, this new algorithm requires less computation since the peak point is simply determined with a single step matrix multiplication. In addition, a good robustness is obtained against external random disturbances on measured intensities since the algorithm is based upon least squares principles.

• Journal of the Korean Vacuum Society
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• v.10 no.2
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• pp.247-251
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• 2001

Photoluminescence(PL) were observed from room temperature to 8K on $Si^+$-implanted silicon-oxide films. The PL intensities are increased from room temperature to 50~80K and decreased below 50K. The blue-shift occurs during the increasing of PL intensity. Also, temperature-dependent PL were measured at peak wavelengths. The first peak is the most sensitive to the measuring temperature. The experimental results are explained by quantum size effect of O rich defects or(and) Si rich defects rather than nanocrystal silicon.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.1
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• pp.15-26
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• 2013

This paper proposes a classification method of parallel, vertical parking states and pillars for parking assist system using ultrasonic sensors. Since, in general parking space detection module, the compressed amplitude of ultrasonic data are received, the analysis of them is difficult. To solve these problems, in preprocessing state, symmetric transform and noise removal are performed. In feature extraction process, four features, standard deviation of distance, reconstructed peak, standard deviation of reconstructed signal and sum of width, are proposed. Gaussian fitting model is used to reconstruct saturated peak signal and discriminability of each feature is measured. To find the best combination among these features, multi-class SVM and subset generator are used for more accurate and robust classification. The proposed method shows 92 % classification rate and proves the applicability to parking space detection modules.

• Speech Sciences
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• v.10 no.2
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• pp.85-95
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• 2003

In speech signal processing, it is very important to detect the pitch exactly in speech recognition, synthesis and analysis. If we exactly pitch detect in speech signal, in the analysis, we can use the pitch to obtain properly the vocal tract parameter. It can be used to easily change or to maintain the naturalness and intelligibility of quality in speech synthesis and to eliminate the personality for speaker-independence in speech recognition. In this paper, we proposed a new pitch detection algorithm. First, positive center clipping is process by using the incline of speech in order to emphasize pitch period with a glottal component of removed vocal tract characteristic in time domain. And rough formant envelope is computed through peak-fitting spectrum of original speech signal infrequence domain. Using the roughed formant envelope, obtain the smoothed formant envelope through calculate the linear interpolation. As well get the flattened harmonics waveform with the algebra difference between spectrum of original speech signal and smoothed formant envelope. Inverse fast fourier transform (IFFT) compute this flattened harmonics. After all, we obtain Residual signal which is removed vocal tract element. The performance was compared with LPC and Cepstrum, ACF. Owing to this algorithm, we have obtained the pitch information improved the accuracy of pitch detection and gross error rate is reduced in voice speech region and in transition region of changing the phoneme.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.3
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• pp.111-121
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• 2002

This study was performed to estimate the degree of consolidation using excess pore water pressure in the very soft ground. The final settlement prediction methods by Hyperbolic, Asaoka and Curve fitting methods from the measured settlement data were used to compare with the degree of consolidation estimated by excess pore water pressure. The dissipated excess pore water pressure during embankment construction and the peak excess pore water pressure on the completed embankment were used for the estimation of the degree of consolidation. After completion of embankment, it was concluded that the degree of consolidation estimated from dissipated excess pore water pressure was more reliable than that from the peak excess pore water pressure. And, the degree of consolidation estimated from the surface settlement was nearly the same as settlement of each layer. The degree of consolidation estimated from dissipated excess pore water pressure was a little larger than that from settlement.

• Explosives and Blasting
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• v.34 no.4
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• pp.28-34
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• 2016

Empirical model, phenomenological model, and CFD model have been used to evaluate the blast effects produced by explosion of explosives, flammable gas and liquid or dust. TNT equivalence method which is one of empirical models has been widely used as it is simple. In this study, new peak overpressure-scaled distance and scaled impulse-scaled distance equations are induced through fitting data from the curves given by TNT equivalence method. If the TNT equivalent mass is calculated, it is possible to estimate the peak overpressure and impulse using the regression equations. Differences of peak overpressure with yield factor which is a component of TNT equivalence method are found to be great in near-by distances from explosion source where the increase in overpressure is very steep, but the differences are getting smaller as the distances increase.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.12C
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• pp.984-994
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• 2010

Pose variation is a critical problem in face recognition. Three-dimensional(3D) face recognition techniques have been proposed, as 3D data contains depth information that may allow problems of pose variation to be handled more effectively than with 2D face recognition methods. This paper proposes a pose-normalized 3D face modeling method that translates and rotates any pose angle to a frontal pose using a plane fitting method by Singular Value Decomposition(SVD). First, we reconstruct 3D face data with stereo vision method. Second, nose peak point is estimated by depth information and then the angle of pose is estimated by a facial plane fitting algorithm using four facial features. Next, using the estimated pose angle, the 3D face is translated and rotated to a frontal pose. To demonstrate the effectiveness of the proposed method, we designed 2D and 3D face recognition experiments. The experimental results show that the performance of the normalized 3D face recognition method is superior to that of an un-normalized 3D face recognition method for overcoming the problems of pose variation.

• Journal of the Korean Ceramic Society
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• v.31 no.10
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• pp.1202-1208
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• 1994

On heating amorphous Pb(Fe2/3W1/3)O3 ceramics, glass transition occurred at 35$0^{\circ}C$, crystallization at 394~420, 485~550 and 540~571$^{\circ}C$ (depending on the heating rates of 2.5~8$0^{\circ}C$/min), phase transformation at 680 and 73$0^{\circ}C$, and melting at 935$^{\circ}C$. A curve-fitting computer program was made using FORTRAN, based on a kinetic equation. Reconstructed thermograms (using the program) turned out to be very close to the measured DSC results for all the heating rates, with average deviation of only 4% at maximum.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.36 no.11
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• pp.783-789
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• 1987

It is anticipated that the accuracy of the numerical value obtained by curve fitting is mainly governed by how to evaluate the term of exponential integral involved in the theory of TSC, so that evaluation process of the instegral term concerned is replaced by Romberg numerical integral method instead of the conventional approximation method of asymtotic expansion or Simmons-Tayler with expectation to get the improved accuracy. In order to examine the effectiveness of the proposed method, the new algorithm is tried to adapt to the peak of TSC observed about 356 K im the specimen of polyethylene terephthalate in which carrier is injected by means of corona dischargel. As theresults, it is confirmed that the proposed method being cooperated with Romberg numerical intergral intergral is superior to the existing conventional curve fitting method.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.74-77
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• 2006

A scanned Fabry-Perot(F-P) filter and a Multi-Channel Wavelength Locker(MCWL) were used to interrogate fiber Bragg grating sensor array. When the F-P filter scans over the MCWL which works as a multi-reference the temporal peaks profiles correspond to the locking wavelengths. To solve the linearity, stability, and accuracy problems caused by the nonlinear response of F-P filter, a polynomial fitting algerian was used to calculate the relationship between the peak locations and the wavelengths in all the scanning range. Then from the reflected peaks locations and the best fitting line, the Bragg wavelengths can be obtained. The measurement linearity was greatly enhanced with wavelength resolution of about 4 pm in 10Hz scanning frequency.