• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 심포지엄 논문집 정보 및 제어부문
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• pp.99-100
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• 2008

This paper proposes a Gaussian Mixture Model (GMM) - based speech emotion recognition methods using four feature parameters; 1) Fast Fourier Transform(FFT) spectral entropy, 2) delta FFT spectral entropy, 3) Mel-frequency Filter Bank (MFB) spectral entropy, and 4) delta MFB spectral entropy. In addition, we use four emotions in a speech database including anger, sadness, happiness, and neutrality. We perform speech emotion recognition experiments using each pre-defined emotion and gender. The experimental results show that the proposed emotion recognition using FFT spectral-based entropy and MFB spectral-based entropy performs better than existing emotion recognition based on GMM using energy, Zero Crossing Rate (ZCR), Linear Prediction Coefficient (LPC), and pitch parameters. In experimental Results, we attained a maximum recognition rate of 75.1% when we used MFB spectral entropy and delta MFB spectral entropy.

• 융합신호처리학회논문지
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• 제9권2호
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• pp.121-128
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• 2008

정확한 음성 구간 검출은 음성 인식 및 음성 코딩 그리고 음성 통신 시스템 등과 같은 음성 어플리케이션의 성능에 큰 영향을 미친다. 본 논문에서는 실제 운전하고 있는 상태에서 다양한 차량 노이즈 환경의 음성 구간 검출 방법을 제안한다. 기존의 음성 구간 검출은 시간 에너지, 주파수 에너지, 영 교차율, spectral entropy 등 다양한 방법을 사용하였으며 잡음 환경에서 급격하게 성능이 저하되는 단점이 있었다. 본 논문에서는 기존의 spectral entropy를 기반으로 하여 MFB(Mel-frequency Filter Banks) spectral entropy, 기울기 FFT(Fast Fourier Transform) spectral entropy, 기울기 MFB spectral entropy를 이용한 음성 구간 검출 방법을 제안한다. MFB는 멜 스케일과 FFT를 곱한 것으로 멜 스케일은 인간이 소리를 인지할 때 주파수에 대해 비선형적인 스케일이며 음성의 특징을 잘 반영한다. 제안한 MFB spectral entropy 방법은 다양한 차량 잡음 환경에서 음성 및 비음성 분별 능력을 향상시킬 수 있으며 실험 결과 93.21%의 음성 구간 검출율을 나타내었다. 이는 기존의 spectral entropy 방법과 비교할 때 MFB를 이용한 음성 구간 검출 방법이 3.2%의 검출율이 향상되었다.

• Bulletin of the Korean Chemical Society
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• 제11권4호
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• pp.276-281
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• 1990

The equivalent conductance of univalent cation (potassium, silver, thallium and ammonium) perchlorates in methanol containing 18-membered crown ethers, 18-crown-6 (18C6) and 1,10-dithia-18-crown-6 (DT18C6) were measured at different temperatures. The equivalent conductances of ammonium perchlorate were increased by increasing content of DT18C6 exceptionally, due to more favorable solvations than complexations. From the equivalent conductance changes, the formation constants for 1:1 compmlexes have been determined, and the values of enthalpy and entropy changes have been calculated. The complexations of 18C6 and DT18C6 with the univalent cations under investigation are all exothermic and the ${\Delta}$S values are all negative and no considerable differences around 50 J/ (k mol). The selectivity order of 18C6 is $K^+ > Tl^+ > Ag^+ > NH_4^+$, while that of DT18C6 is $Ag^+ > Tl^+ > NH_4^+ > K^+$. By sulfur substitutions in 18C6 result in significant decrease in stability, but the stability of $Ag^+$-DT18C6 complex are $10^4$ times larger than those of $K^+$. This increase of stabilities for $Ag^+$-DT18C6 complex are primary due to the result of favorable exothermic heat of reaction between the polarizable soft cation and soft sulfur centers. In NMR experiment, the stepwise additions of cation perchlorates into crown ether solutions induced two major spectral changes. First, the resonance all shift down field and the cation induced shifts were linear up to 1:1 cation/crown ratio, above which no further changes were observed. On the basis of these results, it could be concluded that 1:1 complex is formed. Second, the magnitudes of cation induced shifts were different each other in same ligand. By addition of silver ion to the solution of DT18C6, the largest shift of proton peak near the sulfur atom was observed. These effects are also arisen from the results of covalent bonding between "soft-soft" interactions.