• The Journal of the Acoustical Society of Korea
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• v.20 no.3E
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• pp.10-17
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• 2001

The possibility is investigated of determining the diffuse absorption coefficients of the wall surfaces in a real room by minimizing the errors between the measured energy impulse response of a real room and the predicted energy impulse responses obtained from the ray tracing simulation of the room. In other words, this can possibly serve as a basis for "acoustical system identification" in attempting to determine the "best fit" of modelled absorption coefficients to measured energy response data. Algorithms for attempting this were investigated. The algorithms developed for this purpose proved to be rigorous and efficient. Instead of using the ray tracing model to determine the absorption coefficients, the phase image model was used in order to determine the acoustic impedances of wall surfaces. However, the numerical algorithms could not find the correct impedance values, primarily due to the wide range of the acoustic impedance values of any single acoustic material and very long computation time.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.8
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• pp.411-416
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• 2006

A new method on the evaluation of insulation oil was proposed. Terahertz time-domain spectroscopy (THz-TDS) was applied to investigate the properties of the insulating oil. For the diagnostics of oil degradation, three kinds of oils have been analyzed by THz-TDS. The degraded oil showed different optical and electrical constants compared with a new one. Generally, the power absorption coefficient, the refractive index, the dielectric constant and loss $tan{\delta}$ of the oil increase as the aging of insulating oil proceed. And the characteristics of two kind of insulation oil, 1-4 and 7-4, was compared in terahertz spectral region. Difference in refractive index and complex dielectric constant has been observed between the samples. The results of this study suggest that THz-TDS is a promising new means for evaluating degradation and identification of insulating oil.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.04a
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• pp.9-14
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• 2000

This paper presents the analytical results of local buckling of orthotropic I-shape compression members. Employing the equilibrium approach, the characteristic equation for local buckling of I-shape compression member is derived. Using the derived equation, the minimum buckling coefficients with respect to the ratio of width to thickness for the I-shape column are suggested as a graphical form. In addition, the dominant plate component initiating the local buckling of I-shape column is also identified by using the approximate solution and the results are plotted with dotted line on the minimum bucking coefficient curve.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.5
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• pp.591-597
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• 1997

Instantaneous velocity distribution within coaxial circular pipe for measurement velocity of high speed is acquired simultaneously by applying the 2-dimensional PTV system consisting of a pulse generator(AOM:Acousto-Optical Modulator), a continuous-output laser and a PC image grabber together with experimental apparatus. The basic mechanism of AOM and vector identification method and performance-related image processing techniques are discussed. Representative measuring regions $90{\times}90$mm are selected and instantaneous vectors are represented and fully developed turbulent flow of maximum velocity up to about 1.0 m/sec is obtained.

• Journal of Mechanical Science and Technology
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• v.20 no.12
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• pp.2043-2051
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• 2006

This paper considered identification of vibration characteristics of flexible structure with vector channel periodic lattice filter. We present an algorithm for AR coefficients for the vector-channel lattice filters, and characteristic equation and transfer function are derived from these coefficients. Vibration lattice filter is then constructed from the vector channel lattice filter, and performance of this vibration filter is tested with a test signal which is a combination of many sine waves to compare the performance of scalar and vector channel lattice. Also it is applied to the cantilever data to identify properties of the system, such as natural frequencies and damping ratios, to show its performance.

• Journal of the Korean Society of Tobacco Science
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• v.10 no.1
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• pp.49-57
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• 1988

The phenolic compounds were isolated from the cigarette smoke condensate using two immiscible organic solvents by a partition coefficient. Of them, 20 phenolic compounds were identified by GC and GC/MS. The amount of the phenolic compounds was phenol, p-crestol, hydroxybensoic acid in order. And there was no difference in composition of these compound dependent on leaf tobacco . About 70% amount of these compounds were absorbed to cellulose acetate filter used. The contents and composition of these compounds were various in the commercial cigarette.

• Journal of the Korean Data and Information Science Society
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• v.17 no.4
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• pp.1041-1051
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• 2006

The effectiveness of genetic markers on Hanwoo traceability systems was applied and evaluated from Korean 33 Hanwoo elite sire families. Five microsatellite markers were selected finally, which were located on chromosomes different chromosomes with the end sequencing of 100 HW-YUBAC that were recorded in the NCBI by Yeungnam University. Eleven major microsatellite markers were selected from allele amplified, their frequencies, H(Heterozygosity) and PIC(Polymorphism information content) with Hardy-Weinberg equilibrium. Next, in order to evaluate the power of the markers selected on the individual animal identification with experimental condition, the match probability(MP) and the relatedness coefficient(R) were computed.

• Communications for Statistical Applications and Methods
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• v.13 no.3
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• pp.733-743
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• 2006

To apply and evaluate the effectiveness of genetic markers on Hanwoo traceability systems, samples of 33 Hanwoo individuals from Korean elite sire families were used, and five microsatellite markers were selected finally, which were located on chromosomes different chromosomes with the end sequencing of 100 HW-YUBAC that were recorded in the NCBI by Yeungnam University. Ten major microsatellite markers were selected from alleles amplified, their frequencies, H(Heterozygosity) and PIC(Polymorphism information content) with Hardy-Weinberg equilibrium. Next, in order to evaluate the power of the markers selected on the individual animal identification, the match probability(MP) and the relatedness coefficient(R) were computed.

• Speech Sciences
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• v.7 no.2
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• pp.127-137
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• 2000

This paper presents a macro script to analyze numeric sounds by a speech analysis shareware, Praat, and analyzes those sounds produced by three students who were born and raised in Pusan. Recording was done in a quiet office. To make a meaningful comparison, dynamic time points in relation to the total duration of voicing segments were determined to measure acoustical values. Results showed that a strong correlation coefficient was found between the repetitive production of numeric sounds within and across the speakers. Very high coefficients among diphthongal numbers (0 and 6) which usually show wide formant variation were noticed. This supports that each speaker produced numbers quite coherently. Also, the frequency differences between the three subjects were within a perceptually similar range. To identify a speaker among others may require to find subtle individual differences within this range. Perceptual experiments by synthesized numeric sounds may lead to resolve the issue.

• Speech Sciences
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• v.15 no.3
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• pp.7-15
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• 2008

This paper proposes the method to extract new feature vectors using the difference between the cepstrum for static characteristics and delta cepstrum for dynamic characteristics in speaker recognition (SR). The difference vector (DV) which it proposes from this paper is containing the static and the dynamic characteristics simultaneously at the intermediate characteristic vector which uses the deference between the static and the dynamic characteristics and as the characteristic vector which is new there is a possibility of doing. Compared to the conventional method, the proposed method can achieve new feature vector without increasing of new parameter, but only need the calculation process for the difference between the cepstrum and delta cepstrum. Experimental results show that the proposed method has a good performance more than 2.03%, on average, compared with conventional method in speaker identification (SI).