Speaker Verification with Non-Audible Murmur Segments by Combining Global Alignment Kernel and Penalized Logistic Regression Machine

INTERSPEECH2008: 9th Annual Conference of the International Speech Communication Association, September 22-26, 2008, Brisbane, Australia.We investigate a novel method for speaker verification with nonaudible murmur (NAM) segments. NAM is recorded using a special microphone placed on the neck and is hard for other people to hear. We have already reported a method based on a support vector machine (SVM) using NAM segments to use a keyword phrase effectively. To further exploit keyword-specific features, we introduce a global alignment (GA) kernel and penalized logistic regression machine (PLRM). In the experiments using NAM from 55 speakers, our method achieved an error reduction rate of roughly 60% compared with the SVM-based method using a polynomial kernel

Study on Speaker Verification with Non-Audible Murmur Segments

INTERSPEECH2007: 8th Annual Conference of the International Speech Communication Association, August 27-31, 2007, Antwerp, Belgium.We investigated a speaker verification method that uses non-audible murmur (NAM) segments using newly collected data and obtained several findings that will be useful when speaker verification systems are made in practice. NAM is recorded using a special microphone placed on the surface of the body, so it includes almost no external noise and is hard for other people to hear. By utilizing these properties, we have already reported a text-dependent method using NAM segments that can use a keyword phrase safely. This paper extends the examination with newly collected data consisting of NAM uttered by 18 male and 9 female imposter speakers and by 18 male and 10 female customer speakers. Experiments with various numbers of training utterances and sessions show that it is effective to use data recorded in multiple sessions. We also investigated the minimum number of training utterances needed in our method

Uncertainty analysis and performance evaluation: a measurement of thermophysical properties of liquid Au in microgravity

A new method for quantifying facility performance has been discussed in this study that encompasses uncertainties associated with thermophysical property measurement. Four key thermophysical properties: density, volumetric thermal expansion coefficient, surface tension, and viscosity of liquid Au have been measured in microgravity environment using two different levitation facilities. Levitation experiments were conducted using the Electrostatic Levitation Furnace (ELF) onboard the ISS in Argon and air, and the TEMPUS Electromagnetic Levitation (EML) facility on a Novespace Zero-G aircraft parabolic flight in Argon. The traditional Maximum Amplitude method was augmented through the use of Frequency Crossover method to identify the natural frequency for oscillations induced on a molten sample during Faraday forcing in ESL. The EML tests were conducted using a pulse excitation method where two techniques, one imaging and one non-imaging, were used to study surface oscillations. The results from both facilities are in excellent agreement with the published literature values. A detailed study of the accuracy and precision of the measured values has also been presented in this work to evaluate facility performance

A quantitative comparison of thermophysical property measurement of CMSX-4® Plus (SLS) in microgravity and terrestrial environments

Density, thermal expansion coefficient, surface tension and viscosity of Ni-based CMSX-4® Plus (SLS) have been measured for a range of liquid temperature by utilizing two Electrostatic Levitation (ESL) facilities. Ground-based tests were conducted using the NASA Marshall Space Flight Center ESL facility in 1.33 kPa Ultra High Vacuum and space-based tests were conducted using ISS-ELF facility in 172 kPa Argon gas atmosphere. The measured values were compared to the available literature data. This study focuses on a detailed uncertainty analysis of the experimental data to measure the accuracy and precision of the measured properties using Guide to the expression of Uncertainty Measurement (GUM) principles. The findings from this study have been utilized to quantify the performances of these two ESL facilities in measuring thermophysical properties

A quantitative comparison of thermophysical property measurement of CMSX-4® Plus (SLS) in microgravity and terrestrial environments

International audienceDensity, thermal expansion coefficient, surface tension and viscosity of Ni-based CMSX-4® Plus have been measured for a range of liquid temperature by utilizing two Electrostatic Levitation (ESL) facilities. Ground-based tests were conducted using the NASA Marshall Space Flight Center ESL facility in 1.33 kPa Ultra High Vacuum and space-based tests were conducted using ISS-ELF in 172 kPa Argon gas atmosphere. The measured values were compared to the available literature data. This study focuses on a detailed uncertainty analysis of the experimental data to measure the accuracy and precision of the measured properties using Guide to the expression of Uncertainty Measurement (GUM) principles. The findings from this study have been utilized to quantify the performances of these two ESL facilities in measuring thermophysical properties