Sökning: "Hidden Markov model"

Visar resultat 6 - 10 av 69 avhandlingar innehållade orden Hidden Markov model.

1. 6. Speech Enhancement Using Nonnegative MatrixFactorization and Hidden Markov Models

   Författare :Nasser Mohammadiha; Arne Leijon; W. Bastiaan Kleijn; Cédric Févotte; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Speech enhancement; noise reduction; nonnegative matrix factorization; hidden Markov model; probabilistic latent component analysis; online dictionary learning; super-Gaussian distribution; MMSE estimator; temporal dependencies; dynamic NMF;

   Sammanfattning : Reducing interference noise in a noisy speech recording has been a challenging task for many years yet has a variety of applications, for example, in handsfree mobile communications, in speech recognition, and in hearing aids. Traditional single-channel noise reduction schemes, such as Wiener filtering, do not work satisfactorily in the presence of non-stationary background noise. LÄS MER

3. 7. Model Based Speech Enhancement and Coding

   Författare :David Yuheng Zhao; Bastiaan Kleijn; Peter Kabal; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; statistical model; Gaussian mixture mdel GMM ; hidden Markov model HMM ; moise reduction; Telecommunication; Telekommunikation;

   Sammanfattning : In mobile speech communication, adverse conditions, such as noisy acoustic environments and unreliable network connections, may severely degrade the intelligibility and natural- ness of the received speech quality, and increase the listening effort. This thesis focuses on countermeasures based on statistical signal processing techniques. LÄS MER

4. 8. Hidden Markov Models: Identification, Inverse Filtering and Applications

   Författare :Robert Mattila; Bo Wahlberg; Cristian R. Rojas; John Lygeros; Jan H. van Schuppen; Tobias Rydén; Ayca Özcelikkale; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hidden Markov models; HMM; inverse filtering; identification; estimation; method of moments; counter-adversarial autonomous systems; adversarial signal processing; belief estimation; abdominal aortic aneurysm; medical; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : A hidden Markov model (HMM) comprises a state with Markovian dynamics that is hidden in the sense that it can only be observed via a noisy sensor. This thesis considers three themes in relation to HMMs, namely, identification, inverse filtering and applications. LÄS MER

5. 9. Modelling Allelic and DNA Copy Number Variations using Continuous-index Hidden Markov Models

   Författare :Susann Stjernqvist; Matematisk statistik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hidden Markov models; DNA copy number; allelic copy number; Markov chain Monte Carlo;

   Sammanfattning : In human cells there are usually two copies of each chromosome, but in cancer cells abnormalities could exist. The differences consist of segments of chromosomes with an altered number of copies. There can be deletions as well as amplifications and the lengths of the segments can also vary. LÄS MER

7. 10. Lip-motion and speech biometrics in person recognition

   Författare :Maycel Isaac Faraj; Högskolan i Halmstad; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Audio-visual recognition; biometrics; Biometric recognition; Speaker verification; Speaker authentication; Person identification; Lip movements; Motion; Structure tensor; Orientation; Optical flow; Hidden Markov Model; Gaussian Markov Model; Lip-motion; Image analysis; Bildanalys;

   Sammanfattning : Biometric identification techniques are frequently used to improve security, e.g. in financial transactions, computer networks and secure critical locations. The purpose of biometric authentication systems is to verify an individual by her biological characteristics including those generating characterisitic behaviour. LÄS MER