H. R. Sadegh Mohammadi

@acecr.ac.ir

Communications
Iranian Research Institute for Electrical Engineering, ACECR

H. R. Sadegh Mohammadi


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https://researchid.co/arefeh71
24

Scopus Publications

238

Scholar Citations

9

Scholar h-index

9

Scholar i10-index

Scopus Publications

  • Weighted X-Vectors for Robust Text-Independent Speaker Verification with Multiple Enrollment Utterances
    Mohsen Mohammadi, Hamid Reza Sadegh Mohammadi
    Circuits Systems and Signal Processing, 2022
    Speech is a user-friendly signal for identity recognition with low computational complexity and implementation cost. However, the use of speech samples to identify persons involves several limitations, such as degraded performance in real environments due to the presence of different noises and channel effects. In recent years, deep neural network (DNN)-based approaches have provided good results in speaker verification and outperformed the i-vector based methods. The x-vector is a DNN-based speaker embedding that, in combination with probabilistic linear discriminant analysis (PLDA), increases both the accuracy and robustness of speaker verification systems. In this paper, we propose weighted x-vectors as a method for enhancing the speaker verification system in both clean and noisy environments. It exploits the statistical properties of target speaker enrollment x-vectors for weighting the test x-vector to enhance the scoring accuracy and thus the whole verification system. Experiments were conducted using the VoxCeleb dataset, MFCC feature vectors, and PLDA scoring method. The VoxCeleb is a large-scale dataset that contains real-world short-duration speech samples from over 6,000 speakers. Multicondition training for LDA and PLDA was also employed to improve the system’s performance under mismatched noisy circumstances. The findings showed that using weighted x-vectors led to 18% and 10% reductions in equal error rate (EER) term for clean and noisy conditions, respectively. Also, the experiments show that the increase of the number of enrollment x-vectors results in superior performance of the proposed method.
  • Efficient and robust segmentation and tracking of sperm cells in microscopic image sequences
    Fateme Mostajer Kheirkhah, Hamid Reza Sadegh Mohammadi, Abdolhossein Shahverdi
    Iet Computer Vision, 2019
    Sperm motility analysis is an important factor in male fertility diagnosis. This article presents a hybrid segmentation method to detect sperm cells, which is robust to density variation of the cells in the image sequences. In addition, a preprocessing scheme is employed to remove fixed sperm cells and debris, which facilitate and speed up the cells' tracking stage. The article also proposes an automated sperm-tracking algorithm in semen samples image sequences. It is a multi-step tracking scheme, which is an enhanced version of adaptive window average speed (AWAS) tracking algorithm. It retrieves lost sperm cells during the tracking stage in adjacent frames and alleviates the cells collide problem. The proposed tracking algorithm provides both superior accuracy and higher speed compared to those of the other competitive algorithms for image sequences regardless of their particle densities.
  • Weighted I-Vector Based Text-Independent Speaker Verification System
    Mohsen Mohammadi, Hamid Reza Sadegh Mohammadi
    Icee 2019 27th Iranian Conference on Electrical Engineering, 2019
    Speaker recognition is one of the most common and user-friendly methods for biological signals based people identification. Nowadays, Speaker verification based on factor analysis and i-vector space has a great impact on the performance improvement of these systems. In this paper, a method is proposed for weighting the model and test vectors, which utilizes the statistical characteristics of target training vectors. The effect of the use of weighted vectors on the accuracy of scoring and the performance of the entire speaker verification system was evaluated for Mel-frequency cepstral coefficients (MFCC) and power-normalized cepstral coefficients (PNCC) feature vectors, and two scoring methods, i.e., the cosine distance and probabilistic linear discriminant analysis (PLDA). TIMIT database has been used in the evaluation of the system. The test results indicate that the use of proposed weighted vectors reduces the error rate of the speaker verification system significantly.
  • Discriminant Analysis Methods Comparison in I-Vector Space for Speaker Verification
    Mohsen Mohammadi, Hamid Reza Sadegh Mohammadi
    9th International Symposium on Telecommunication with Emphasis on Information and Communication Technology Ist 2018, 2018
    Identity vectors are the state-of-the-art feature vectors for speaker recognition applications. One of the most important advantages of i-vector is its allowance for implementation of channel and noise compensatory methods such as linear discriminant analysis (LDA). The motivation for this is to look for new orthogonal axes to achieve superior discrimination between different classes. The axes should comply with the inter-class variance maximization and intra-class variance minimization requirements. The conventional method for the LDA transform computation considers Gaussian distribution assumption and uses parametric representations for both intra- and inter-speaker scatter matrices. Of course, the actual distribution of i-vectors may not necessarily be Gaussian. In this paper, we investigate the performance of LDA, and three nonparametric techniques, i.e., NDA, GDA, and SVDA separately and in combination with LDA. Experiments were conducted on TIMIT and NIST SRE 2008 datasets with MFCC and PNCC feature vectors. The results show that using the combination of parametric and nonparametric methods can lead to better results.
  • Modified histogram-based segmentation and adaptive distance tracking of sperm cells image sequences
    Fateme Mostajer Kheirkhah, Hamid Reza Sadegh Mohammadi, Abdolhossein Shahverdi
    Computer Methods and Programs in Biomedicine, 2018
    Proper recognition and tracking of microscopic sperm cells in video images are vital steps of male infertility diagnosis and treatment. The segmentation and detection of sperms in microscopic image analysis is a complicate process as a result of their small sizes, fast movements, and considerable collisions. Histogram-based thresholding schemes are very popular for this purpose, since they are quite fast and provide almost acceptable results. This paper proposes a combined method for sperm cells detection, which consists of a non-linear pre-processing stage, a histogram-based thresholding algorithm, and a tracking method based on an adaptive distance scheme. The results of conducted experiments verify the superiority of the proposed scheme with incorporated Kittler algorithm compared to the other competitive methods in the majority of cases.
  • Robust features fusion for text independent speaker verification enhancement in noisy environments
    Mohsen Mohammadi, Hamid Reza Sadegh Mohammadi
    2017 25th Iranian Conference on Electrical Engineering Icee 2017, 2017
    So far, many methods have been proposed for speaker verification which provide good results, but their performances reduce in actual noisy environments. A common approach to partially alleviate this problem is the fusion of several methods. In this paper, four systems based on different speech features, i.e., MFCC, IMFCC, LFCC, and PNCC were combined in score-level to improve verification accuracy under clean and noisy speech conditions. The features pairwise and foursome fusion in a speaker verification system based on speaker modeling through the Gaussian mixture model (GMM) were evaluated. TIMIT and NOISEX92 databases were used to implement as the speech and noise datasets, respectively. The experimental results show that the score-level fusion of different feature vectors enhances the accuracy of speaker verification system and this reduces the equal error rates is in some cases up to 44%.
  • Study of speech features robustness for speaker verification application in noisy environments
    Mohsen Mohammadi, Hamid Reza Sadegh Mohammadi
    2016 8th International Symposium on Telecommunications Ist 2016, 2017
    This paper presents a comparative study and evaluation of the performances of four speech feature vectors, i.e., MFCC, IMFCC, LFCC, and PNCC in a speaker verification system based on speaker modeling through the Gaussian mixture model (GMM) under clean and noisy speech conditions. The TIMIT and NOISEX92 dataset were used in implementing the tests for speech signal and noise, respectively. The evaluation results show that IMFCC and PNCC provide superior performance in the presence of noise. In order to enhance the performance of the system under noisy conditions, the application of spectral subtraction algorithm as a pre-processing stage was investigated. It only improved the performance for the speech signal contaminated with white noise.
  • Histogram non-linear transform for sperm cells image detection enhancement
    F. Mostajer Kheirkhah, H. R. Sadegh Mohammadi, A. Shahverdi
    2016 8th International Conference on Information and Knowledge Technology Ikt 2016, 2016
    Proper recognition of microscopic sperm cells in video images is an important step in diagnosis and treatment of male infertility. The small sizes of the sperm cells make their segmentation and detection an important stage in the microscopic images analysis. Histogram-based thresholding schemes are one of the common approaches for this purpose. This paper proposes a non-linear amplitude compression transform method applied as a pre-processing stage for histogram-based thresholding algorithms. The results of conducted experiments verify the higher performance of the proposed scheme when used with Kittler method compared to its utilization with the other competitive algorithms in most cases for this application.
  • Joint frame and Gaussian selection for text independent speaker verification
    Rahim Saeidi, Tomi Kinnunen, Hamid Reza Sadegh Mohammadi, Robert Rodman, Pasi Franti
    ICASSP IEEE International Conference on Acoustics Speech and Signal Processing Proceedings, 2010
    Gaussian selection is a technique applied in the GMM-UBM framework to accelerate score calculation. We have recently introduced a novel Gaussian selection method known as sorted GMM (SGMM). SGMM uses scalar-indexing of the universal background model mean vectors to achieve fast search of the top-scoring Gaussians. In the present work we extend this method by using 2-dimensional indexing, which leads to simultaneous frame and Gaussian selection. Our results on the NIST 2002 speaker recognition evaluation corpus indicate that both the 1- and 2- dimensional SGMMs outperform frame decimation and temporal tracking of top-scoring Gaussians by a wide margin (in terms of Gaussian computations relative to GMM-UBM as baseline).
  • Particle swarm optimization for sorted adapted gaussian mixture models
    R. Saeidi, H.R.S. Mohammadi, T. Ganchev, R.D. Rodman
    IEEE Transactions on Audio Speech and Language Processing, 2009
    Recently, we introduced the sorted Gaussian mixture models (SGMMs) algorithm providing the means to tradeoff performance for operational speed and thus permitting the speed-up of GMM-based classification schemes. The performance of the SGMM algorithm depends on the proper choice of the sorting function, and the proper adjustment of its parameters. In the present work, we employ particle swarm optimization (PSO) and an appropriate fitness function to find the most advantageous parameters of the sorting function. We evaluate the practical significance of our approach on the text-independent speaker verification task utilizing the NIST 2002 speaker recognition evaluation (SRE) database while following the NIST SRE experimental protocol. The experimental results demonstrate a superior performance of the SGMM algorithm using PSO when compared to the original SGMM. For comprehensiveness we also compared these results with those from a baseline Gaussian mixture model-universal background model (GMM-UBM) system. The experimental results suggest that the performance loss due to speed-up is partially mitigated using PSO-derived weights in a sorted GMM-based scheme.
  • Hierarchical mixture clustering and its application to GMM based text independent speaker identification
    R. Saeidi, H. R. Sadegh Mohammadi, T. Ganchev, R. D. Rodman
    2008 International Symposium on Telecommunications Ist 2008, 2008
  • Field simulation of a high voltage inductor for series resonant generator
    A. A. Lotfi Neyestanak, M. Jahanbakht, H. R. Sadegh Mohammadi, A. Graeeli
    Journal of Electromagnetic Waves and Applications, 2008
  • Effects of feature domain normalizations on text independent speaker verification using sorted adapted Gaussian mixture models
    Rahim Saeidi, Hamid Reza Sadegh Mohammadi, Todor Ganchev, Robert D. Rodman
    Communications in Computer and Information Science, 2008
  • Speaker identification performance enhancement using Gaussian mixture model with GMM classification post-processor
    H. R. Sadegh Mohammadi, R. Saeidi
    Icspc 2007 Proceedings 2007 IEEE International Conference on Signal Processing and Communications, 2007
  • Text independent speaker verification using enhanced sorted Gaussian mixture model
    R. Saeidi, T. Ganchev, H. R. Sadegh Mohammadi
    Icspc 2007 Proceedings 2007 IEEE International Conference on Signal Processing and Communications, 2007
  • A new segmentation algorithm combined with transient frames power for text independent speaker verification
    R. Saeidi, H. R. Sadegh Mohammadi, R. D. Rodman, T. Kinnunen
    ICASSP IEEE International Conference on Acoustics Speech and Signal Processing Proceedings, 2007
  • Combined inter-frame and intra-frame fast scoring methods for efficient implementation of GMM-based speaker verification systems
    H. R. Sadegh Mohammadi, R. Saeidi, M. R. Rohani, R. D. Rodman
    ICASSP IEEE International Conference on Acoustics Speech and Signal Processing Proceedings, 2007
  • Iranian Journal of Electrical and Computer Engineering: Editorial Note
    Iranian Journal of Electrical and Computer Engineering, 2006
  • Efficient implementation of GMM based speaker verification using sorted Gaussian mixture model
    European Signal Processing Conference, 2006
  • An efficient gmm classification post-processing method for structural Gaussian mixture model based speaker verification
    ICASSP IEEE International Conference on Acoustics Speech and Signal Processing Proceedings, 2006
  • Iranian Journal of Electrical and Computer Engineering: Editorial Note
    Iranian Journal of Electrical and Computer Engineering, 2005
  • Iranian Journal of Electrical and Computer Engineering: Editorial note
    Iranian Journal of Electrical and Computer Engineering, 2004
  • Efficient spectral coding of speech using generalized Sorted Codebook Vector Quantization applied to LSF parameters
    Scientia Iranica, 1999
  • Efficient coding of the short-term speech spectrum with two-step vector quantization methods
    IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences, 1995

RECENT SCHOLAR PUBLICATIONS

  • Weighted X-Vectors for Robust Text-Independent Speaker Verification with Multiple Enrollment Utterances
    M Mohammadi, HR Sadegh Mohammadi
    Circuits, Systems, and Signal Processing 41 (5), pp. 2825-2844, s00034-021 … , 2022
    2022
    Citations: 7
  • Design, Development and Fabrication of Two-Parameter Synthetic Short-Circuit Test for VCB Using Nnetwork-Connected Current Circuit
    A Omidkhoda, J Jafari Behnam, MS Mirghafourian, A Geraiely, ...
    Nashriyyah-i Muhandisi-i Barq va Muhandisi-i Kampyutar-i Iran 79 (2), 88 , 2020
    2020
  • Efficient and Robust Segmentation and Tracking of Sperm Cells in Microscopic Image Sequences
    F Mostajer Kheirkhah, HR Sadegh Mohammadi, A Shahverdi
    IET Computer Vision 13 (5), 489-499 , 2019
    2019
    Citations: 16
  • Weighted I-vector based text-independent speaker verification system
    M Mohammadi, HRS Mohammadi
    2019 27th Iranian Conference on Electrical Engineering (ICEE), 1647-1653 , 2019
    2019
    Citations: 2
  • Discriminant Analysis Methods Comparison in I-Vector Space for Speaker Verification
    M Mohammadi, HR Sadegh Mohammadi
    The 9th International Symposium on Telecommunications (IST'2018), 166-172 , 2018
    2018
  • Modified Histogram-Based Segmentation and Adaptive Distance Tracking of Sperm Cells Image Sequences
    F Mostajer Kheirkhah, HR Sadegh Mohammadi, A Shahverdi
    Computer Methods and Programs in Biomedicine 154, 173-182 , 2018
    2018
    Citations: 16
  • Design and Manufacturing of a One Million Volt Residual Voltage Lightning Current Generator
    A Omidkhoda, J Jafari Behnam, MS Mirghafourian, A Geraieli, ...
    Nashriyyah-i Muhandisi-i Barq va Muhandisi-i Kampyutar-i Iran 53 (1), 39 , 2017
    2017
  • Robust Features Fusion for Text Independent Speaker Verification Enhancement in Noisy Environments
    M Mohammadi, HR Sadegh Mohammadi
    25th Iranian Conference on Electrical Engineering, 5 pp. , 2017
    2017
    Citations: 28
  • Study of Speech Features Robustness for Speaker Verification Application in Noisy Environments
    M Mohammadi, HR Sadegh Mohammadi
    8th International Symposium on Telecommunications, 5 pp. , 2016
    2016
    Citations: 2
  • Histogram Non-Linear Transform for Sperm Cells Image Detection Enhancement
    F Mostajer Kheirkhah, HR Sadegh Mohammadi, A Shahverdi
    Eighth International Conference on Information and Knowledge Technology (IKT … , 2016
    2016
    Citations: 8
  • Joint frame and Gaussian selection for text independent speaker verification
    R Saeidi, T Kinnunen, HR Sadegh Mohammadi, R Rodman, P Fränti
    2010 IEEE International Conference on Acoustics, Speech and Signal … , 2010
    2010
    Citations: 8
  • Joint frame and gaussian selection for text independent speaker verification
    HRS Mohammadi
    … Speech and Signal… , 2010
    2010
  • Particle Swarm Optimization for Sorted Adapted Gaussian Mixture Models
    R Saeidi, HR Sadegh Mohammadi, T Ganchev, RD Rodman
    IEEE Transactions on Audio, Speech, and Language Processing 17 (2), 344 - 353 , 2009
    2009
    Citations: 37
  • Design and Implementation of a Computer System for Partial Discharge Process and Detection
    AAL Neyestanak, HR Sadegh Mohammadi, AE Forooshani, A Graeili
    Electric Power Conference, 2008. EPEC 2008. IEEE Canada, 1-6 , 2008
    2008
    Citations: 2
  • Hierarchical mixture clustering and its application to GMM based text independent speaker identification
    R Saeidi, HR Sadegh Mohammadi, T Ganchev, RD Rodman
    2008 International Symposium on Telecommunications, 770-773 , 2008
    2008
    Citations: 4
  • Effects of Feature Domain Normalizations on Text Independent Speaker Verification Using Sorted Adapted Gaussian Mixture Models
    R Saeidi, HR Sadegh Mohammadi, T Ganchev, RD Rodman
    Computer Society of Iran Computer Conference, 493-500 , 2008
    2008
    Citations: 1
  • Field Simulation of a High Voltage Inductor for Series Resonant Generator
    AA Lotfi Neyestanak, M Jahanbakht, HR Sadegh Mohammadi, A Graeeli
    Journal of Electromagnetic Waves and Applications 22 (17-18), 2391-2398 , 2008
    2008
  • Text Independent Speaker Verification using Enhanced Sorted Gaussian Mixture Model
    R Saeidi, T Ganchev, HR Sadegh Mohammadi
    2007 IEEE International Conference on Signal Processing and Communications … , 2007
    2007
  • Speaker identification performance enhancement using Gaussian mixture model with GMM classification post-processor
    HR Sadegh Mohammadi, R Saeidi
    2007 IEEE International Conference on Signal Processing and Communications … , 2007
    2007
    Citations: 10
  • Design and Implementation of a 125 kV/1000 kVA High-Voltage Test System Using Series-Resonance Technique
    AA Lotfi-Neyestanak, HR Sadegh Mohammadi
    Nashriyyah-i Muhandisi-i Barq va Muhandisi-i Kampyutar-i Iran 11 (3), 129 , 2007
    2007

MOST CITED SCHOLAR PUBLICATIONS

  • Particle Swarm Optimization for Sorted Adapted Gaussian Mixture Models
    R Saeidi, HR Sadegh Mohammadi, T Ganchev, RD Rodman
    IEEE Transactions on Audio, Speech, and Language Processing 17 (2), 344 - 353 , 2009
    2009
    Citations: 37
  • Robust Features Fusion for Text Independent Speaker Verification Enhancement in Noisy Environments
    M Mohammadi, HR Sadegh Mohammadi
    25th Iranian Conference on Electrical Engineering, 5 pp. , 2017
    2017
    Citations: 28
  • Efficient implementation of GMM based speaker verification using sorted Gaussian mixture model
    HR Sadegh Mohammadi, R Saeidi
    14th European Signal Processing Conference, 2006, 1-4 , 2006
    2006
    Citations: 20
  • A new segmentation algorithm combined with transient frames power for text independent speaker verification
    R Saeidi, HR Sadegh Mohammadi, RD Rodman, T Kinnunen
    2007 IEEE International Conference on Acoustics, Speech and Signal … , 2007
    2007
    Citations: 18
  • Low cost vector quantization methods for spectral coding in low rate speech coders
    HR Sadegh Mohammadi, WH Holmes
    1995 International Conference on Acoustics, Speech, and Signal Processing 1 … , 1995
    1995
    Citations: 18
  • Efficient and Robust Segmentation and Tracking of Sperm Cells in Microscopic Image Sequences
    F Mostajer Kheirkhah, HR Sadegh Mohammadi, A Shahverdi
    IET Computer Vision 13 (5), 489-499 , 2019
    2019
    Citations: 16
  • Modified Histogram-Based Segmentation and Adaptive Distance Tracking of Sperm Cells Image Sequences
    F Mostajer Kheirkhah, HR Sadegh Mohammadi, A Shahverdi
    Computer Methods and Programs in Biomedicine 154, 173-182 , 2018
    2018
    Citations: 16
  • An efficient GMM classification post-processing method for structural Gaussian mixture model based speaker verification
    R Saeidi, HR Sadegh Mohammadi, MK Amirhosseini
    2006 IEEE International Conference on Acoustics Speech and Signal Processing … , 2006
    2006
    Citations: 11
  • Speaker identification performance enhancement using Gaussian mixture model with GMM classification post-processor
    HR Sadegh Mohammadi, R Saeidi
    2007 IEEE International Conference on Signal Processing and Communications … , 2007
    2007
    Citations: 10
  • Histogram Non-Linear Transform for Sperm Cells Image Detection Enhancement
    F Mostajer Kheirkhah, HR Sadegh Mohammadi, A Shahverdi
    Eighth International Conference on Information and Knowledge Technology (IKT … , 2016
    2016
    Citations: 8
  • Joint frame and Gaussian selection for text independent speaker verification
    R Saeidi, T Kinnunen, HR Sadegh Mohammadi, R Rodman, P Fränti
    2010 IEEE International Conference on Acoustics, Speech and Signal … , 2010
    2010
    Citations: 8
  • Combined inter-frame and intra-frame fast scoring methods for efficient implementation of GMM-based speaker verification systems
    S Mohammadi HR, R Saeidi, MR Rohani, RD Rodman
    2007 IEEE International Conference on Acoustics, Speech and Signal … , 2007
    2007
    Citations: 8
  • Study of model parameters effects in adapted Gaussian mixture models based text independent speaker verification
    R Saeidi, HR Sadegh Mohammadi, MK Amirhosseini
    Proc. International Symp. of Telecommunications, IST 2005 1, 387-392 , 2005
    2005
    Citations: 8
  • Weighted X-Vectors for Robust Text-Independent Speaker Verification with Multiple Enrollment Utterances
    M Mohammadi, HR Sadegh Mohammadi
    Circuits, Systems, and Signal Processing 41 (5), pp. 2825-2844, s00034-021 … , 2022
    2022
    Citations: 7
  • Fine-coarse split vector quantization: an efficient method for spectral coding
    HR Sadegh Mohammadi, WH Holmes
    Fifth Australian International Conference on Speech Science and Technology 1 … , 1994
    1994
    Citations: 6
  • Hierarchical mixture clustering and its application to GMM based text independent speaker identification
    R Saeidi, HR Sadegh Mohammadi, T Ganchev, RD Rodman
    2008 International Symposium on Telecommunications, 770-773 , 2008
    2008
    Citations: 4
  • Efficient GMM-UBM system in text independent speaker verification using structural Gaussian mixture models,''
    R Saeidi, HR Sadegh Mohammadi, MK Amirhosseini
    Proc. International Symp. of Telecommunications, IST2005 1, 39-44 , 2005
    2005
    Citations: 3
  • Weighted I-vector based text-independent speaker verification system
    M Mohammadi, HRS Mohammadi
    2019 27th Iranian Conference on Electrical Engineering (ICEE), 1647-1653 , 2019
    2019
    Citations: 2
  • Study of Speech Features Robustness for Speaker Verification Application in Noisy Environments
    M Mohammadi, HR Sadegh Mohammadi
    8th International Symposium on Telecommunications, 5 pp. , 2016
    2016
    Citations: 2
  • Design and Implementation of a Computer System for Partial Discharge Process and Detection
    AAL Neyestanak, HR Sadegh Mohammadi, AE Forooshani, A Graeili
    Electric Power Conference, 2008. EPEC 2008. IEEE Canada, 1-6 , 2008
    2008
    Citations: 2