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Université de Neuchâtel

GSM speech coding and speaker recognition

Besacier, Laurent ; Grassi, Sara ; Dufaux, Alain ; Ansorge, Michael ; Pellandini, Fausto

In: Proceedings of the International Conference on Acoustics, Speech, and Signal Processing (ICASSP97), 2000, vol. 2, p. 1085-1088

This paper investigates the influence of GSM speech coding on text independent speaker recognition performance. The three existing GSM speech coder standards were considered. The whole TIMIT database was passed through these coders, obtaining three transcoded databases. In a first experiment, it was found that the use of GSM coding degrades significantly the identification and verification...

Université de Neuchâtel

Etude du cratère du Nördlingen-Ries (Allemagne) selon les macles de la calcite

Girardin, Claude ; Burkhard, Martin (Dir.)

Mémoire de diplôme universitaire : Université de Neuchâtel, 2006.

Ce travail de diplôme porte sur l’étude des macles de la calcite autour du cratère du Nördlingen-Ries (Allemagne). Ce cratère de météorite a un diamètre de 25 km environ et est âgé de 14.7 Ma. Celui-ci se situe dans le Jura Souabe et les roches affleurentes sont composées de calcaire d’âge jurassique. Les macles sont utilisées pour déterminer les déformations enregistrées...

Université de Neuchâtel

Adaptive block-size transform coding for image compression

Bracamonte, Javier ; Ansorge, Michael ; Pellandini, Fausto

In: Proceedings of the International Conference on Acoustics, Speech, and Signal Processing (ICASSP97), 1997, vol. 4, p. 2721-2724

In this paper we report the results of an adaptive block-size transform coding scheme that is bascd on the sequential JPEG algorithm. This minimum information-overhead method implies a transform coding technique with two différent block sizes: N x N and 2N x 2N pixels. The input image is divided into blocks of 2N x 2N pixels and each of these bocks is...

Université de Neuchâtel

Efficient algorithm to compute LSP parameters from 10th-order LPC coefficients

Grassi, Sara ; Dufaux, Alain ; Ansorge, Michael ; Pellandini, Fausto

In: Proceedings of the International Conference on Acoustics, Speech, and Signal Processing (ICASSP97), 1997, vol. 3, p. 1707-1710

Line Spectrum Pair (LSP) representation of Linear Predictive Coding (LPC) parameters is widely used in speech coding applications. An efficient method for LPC to LSP conversion is Kabal’s method. In this method the LSPs are the roots of two polynomials P'p(x) and Q'p(x), and are found by a zero crossing search followed by successive bisections and interpolation. The...

Université de Neuchâtel

Influence of GSM speech coding algorithms on the performance of text-independent speaker indentification

Grassi, Sara ; Besacier, Laurent ; Dufaux, Alain ; Ansorge, Michael ; Pellandini, Fausto

In: Proceedings of the International COST 254 Workshop on Intelligent Communication Technologies and Applications, with Emphasis on Mobile Communications, 1999, vol. 254, p. 307-311

This paper investigates the influence, on theperformance of a text-independent speaker identification system, of the three speech coding algorithmsstandardized for use in the GSM wireless communication network. The speaker identification system isbased on Gaussian Mixture Models (GMM) classifiers. Only the influence of the speech codingalgorithms was taken into account. This was done bypassing...

Université de Neuchâtel

Interactions between environmental change and shallow water carbonate buildup along the northern Tethyan margin and their impact on the Early Cretaceous carbon isotope record

Föllmi, Karl B. ; Godet, Alexis ; Bodin, Stéphane ; Linder, Pascal

In: Paleoceanography, 2006, vol. 21, no. PA4211, p. 1-16

The evolution of the Early Cretaceous, northern Tethyan carbonate platform was not only influenced by changes in sea level, detrital influx, and surface water temperature but also by changes in trophic levels. We distinguish between phases of carbonate production dominated by oligotrophic photozoan communities and by mesotrophic and eventually colder-water heterozoan communities. Superimposed on...

Université de Neuchâtel

Speaker recognition on compressed speech

Grassi, Sara ; Dufaux, Alain ; Besacier, Laurent ; Ansorge, Michael ; Pellandini, Fausto

In: Proceedings of the International COST 254 Workshop on Friendly Exchanging through the Net, 2000, vol. 254, p. 117-122

We have investigated the influence of GSM speechcoding in the performance of a text-independent speakerrecognition system based on Gaussian Mixture Models(GMM) classifiers.The performance degradation due to the utilization ofthe three GSM speech coders was first assessed, usingthree transcoded databases, obtained by passing theTIMIT through each GSM coder / decoder. The codeddatabases were used...

Université de Neuchâtel

Implementation of Automatic Speech Recognition for Low-Power Miniaturized Devices

Grassi, Sara ; Ansorge, Michael ; Pellandini, Fausto ; Farine, Pierre-André

In: Proceedings of the 5th COST 276 Workshop on Information and Knowledge Management for Integrated Media Communication, 2003, vol. 276, no. 5, p. 59-64

This paper describes the development and implementation of a discrete speech recognizer for application in miniaturized, portable low-power devices. The recognizer is based on Hidden Markov Models (HMMs) and uses Linear Predictive Coefficients (LPC) converted to cepstrum to parameterize the input speech. The implemented recognizer has a complexity of 0.67 MIPS and a recognition performance of...

Université de Neuchâtel

Low Complexity Image Matching in the Compressed Domain by using the DCT-phase

Bracamonte, Javier ; Ansorge, Michael ; Pellandini, Fausto ; Farine, Pierre-André

In: Proceedings of the 6th COST 276 Workshop on Information and Knowledge Management for Integrated Media Communication, 2004, vol. 267, no. 6, p. 88-93

This paper presents a new, simple, and efficient algorithm for image matching in the compressed domain. The proposed technique operates directly on transformed frequency-domain data, which makes it a good choice when dealing with standard-compliant Discrete Cosine Transform (DCT)-based compressed images since it avoids the large computational overhead associated with the decoding stage....

Université de Neuchâtel

Distributed speaker recognition using the ETSI Aurora standard

Grassi, Sara ; Ansorge, Michael ; Pellandini, Fausto ; Farine, Pierre-André

In: Proceedings of the 3rd COST 276 Workshop on Information and Knowledge Management for Integrated Media Communication, 2002, vol. 276, no. 3, p. 120-125

The ETSI “Aurora” is a standard for distributed speech recognition over the mobile cellular network. We have investigated the use of the features defined in this standard for speaker recognition, in a text-independent system based on Gaussian Mixture Models (GMM). The application context is distributed speaker recognition for user authentication on the mobile cellular network....