• فهرست مقالات Gaussian Mixture Model

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        1 - Recognizing the Emotional State Changes in Human Utterance by a Learning Statistical Method based on Gaussian Mixture Model
        Reza Ashrafidoost Saeed Setayeshi Arash Sharifi
        Speech is one of the most opulent and instant methods to express emotional characteristics of human beings, which conveys the cognitive and semantic concepts among humans. In this study, a statistical-based method for emotional recognition of speech signals is proposed, چکیده کامل
        Speech is one of the most opulent and instant methods to express emotional characteristics of human beings, which conveys the cognitive and semantic concepts among humans. In this study, a statistical-based method for emotional recognition of speech signals is proposed, and a learning approach is introduced, which is based on the statistical model to classify internal feelings of the utterance. This approach analyzes and tracks the emotional state changes trend of speaker during the speech. The proposed method classifies utterance emotions in six standard classes including, boredom, fear, anger, neutral, disgust and sadness. For this purpose, it is applied the renowned speech corpus database, EmoDB, for training phase of the proposed approach. In this process, once the pre-processing tasks are done, the meaningful speech patterns and attributes are extracted by MFCC method, and meticulously selected by SFS method. Then, a statistical classification approach is called and altered to employ as a part of the method. This approach is entitled as the LGMM, which is used to categorize obtained features. Aftermath, with the help of the classification results, it is illustrated the emotional states changes trend to reveal speaker feelings. The proposed model also has been compared with some recent models of emotional speech classification, in which have been used similar methods and materials. Experimental results show an admissible overall recognition rate and stability in classifying the uttered speech in six emotional states, and also the proposed algorithm outperforms the other similar models in classification accuracy rates. پرونده مقاله
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        2 - Negative Selection Based Data Classification with Flexible Boundaries
        Lena Nemati Mojtaba Shakeri
        One of the most important artificial immune algorithms is negative selection algorithm, which is an anomaly detection and pattern recognition technique; however, recent research has shown the successful application of this algorithm in data classification. Most of the n چکیده کامل
        One of the most important artificial immune algorithms is negative selection algorithm, which is an anomaly detection and pattern recognition technique; however, recent research has shown the successful application of this algorithm in data classification. Most of the negative selection methods consider deterministic boundaries to distinguish between self and non-self-spaces. In this paper, two negative selection based algorithms are proposed for two-class and multi-class classification problems; using a Gaussian mixture model which is fitted on normal space to create a flexible boundary between self and non-self-spaces, by determining the dynamic subsets of effective detectors to solve the problem of data classification. Initialization of effective parameters such as the detection threshold, the maximum number of detectors etc. for each dataset, is one of the challenges in negative selection based classification algorithms, which affects the precision and accuracy of the classification; therefore, an adaptive and optimal calculation of these parameters is necessary. To overcome this problem, the particle swarm optimization algorithm has been used to properly set the parameters of the proposed methods. The experimental results showed that using a Gaussian mixture model and dynamic adjustment of parameters such as optimum number of Gaussian components according to the shape of the boundaries, creation of appropriate number of detectors, and also automatic adjustment of the training and testing thresholds, using particle swarm optimization algorithm as well as utilization of a combinatorial objective function has led to a better classification with fewer detectors. The proposed algorithms showed competitive performance compared with some of the existing classification algorithms, including several immune-inspired models, especially negative selection ones, and other traditional classification methods. پرونده مقاله
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        3 - روشی جدید جهت بخش‌بندی ضایعات مالتیپل اسکلروزیس (MS) در تصاویر MR مغزی
        سیمین جعفری علیرضا کریمیان
        بخش‌بندی ضایعات مالتیپل اسکلروزیس (MS) در تصاویر MR مغزی به منظور کمک به تشخیص و پیگیری این بیماری در سالهای اخیر مورد توجه قرار گرفته است. در این مطالعه از مدل ترکیب گوسی (GMM) برای قطعه‌بندی ضایعات MS در تصاویر MR استفاده شد. به منظور بهینه‌سازی GMM از الگوریتم بیشینه چکیده کامل
        بخش‌بندی ضایعات مالتیپل اسکلروزیس (MS) در تصاویر MR مغزی به منظور کمک به تشخیص و پیگیری این بیماری در سالهای اخیر مورد توجه قرار گرفته است. در این مطالعه از مدل ترکیب گوسی (GMM) برای قطعه‌بندی ضایعات MS در تصاویر MR استفاده شد. به منظور بهینه‌سازی GMM از الگوریتم بیشینه‌سازی امید ریاضی (EM) استفاده می‌شود اما این الگوریتم معمولاً به یک نقطه بهینه محلی همگرا می‌شود که برای رهایی از گیر افتادن در این نقطه، الگوریتم را از نقاط شروع متفاوت اجرا کرده و بهترین نتیجه ذخیره می‌شود که کاری زمانبر است. در این مقاله از استراتژی متفاوتی به منظور تسریع و افزایش دقت این الگوریتم استفاده شده است. همچنین به منظور کاهش میزان محاسبات و افزایش دقت الگوریتم EM، از الگوریتم Fast Trimmed-Likelihood استفاده شد. جهت اعتبارسنجی روش پیشنهادی، تصاویر ناحیه‌بندی شده به روش خودکار با تصاویر ناحیه‌بندی شده توسط دو فرد متخصص مقایسه شده است. نتایج حاصل نشان می‌دهد روش پیشنهادی با کسب رتبه 82% برای ضریب تشابه Dice، قابلیت این را دارد که با دقت بالایی ضایعات MS را تشخیص داده و بخش‌بندی نماید پرونده مقاله
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        4 - Voiced-Unvoiced-Silence Detection of Speech Signal using Combined Spectro-Temporal Features
        Nafiseh Esfandian
        This paper presents a new method for classification of voiced, unvoiced and silence segments of speech signal. In the proposed method, combination of spectro-temporal features is used for speech segmentation. Combined features are extracted using clustering in spectro-t چکیده کامل
        This paper presents a new method for classification of voiced, unvoiced and silence segments of speech signal. In the proposed method, combination of spectro-temporal features is used for speech segmentation. Combined features are extracted using clustering in spectro-temporal domain. Multi-dimensional output of auditory model is clustered using weighted Gaussian mixture model. In this method, after extracting the main clusters for each frame, combined spectro-temporal features such as cluster’s energy, energy difference of clusters and minimum value of normalized cross-correlation between clusters are used for detection of voiced, unvoiced and silence regions of speech. In the proposed algorithm, speech segmentation is performed by comparing each class of features with the appropriate threshold value. Combined spectro-temporal features are used for speech segmentation in noisy conditions. The results demonstrate performance of the proposed algorithm comparing to the other features for speech segmentation. پرونده مقاله
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        5 - A Hybrid of Genetic Algorithm and Gaussian Mixture Model for Features Reduction and Detection of Vocal Fold Pathology
        Vahid Majidnezhad Igor Kheidorov
        Acoustic analysis is a proper method in vocal fold pathology diagnosis so that it can complement and in some cases replace the other invasive, based on direct vocal fold observation, methods. There are different approaches and algorithms for vocal fold pathology diagnos چکیده کامل
        Acoustic analysis is a proper method in vocal fold pathology diagnosis so that it can complement and in some cases replace the other invasive, based on direct vocal fold observation, methods. There are different approaches and algorithms for vocal fold pathology diagnosis. These algorithms usually have three stages which are Feature Extraction, Feature Reduction and Classification. In this paper initial study of feature extraction and feature reduction in the task of vocal fold pathology diagnosis has been presented. A new type of feature vector, based on wavelet packet decomposition and Mel-Frequency-Cepstral-Coefficients (MFCCs), is proposed. Also a new GA-based method for feature reduction stage is proposed and compared with conventional methods such as Principal Component Analysis (PCA). Gaussian Mixture Model (GMM) is used as a classifier for evaluating the performance of the proposed method. The results show the priority of the proposed method in comparison with current methods. پرونده مقاله
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        6 - Random Texture Defect Detection by Modeling the Extracted Features from the Optimal Gabor Filter
        S.Abdollah Mirmahdavi Abdollah Amirkhani Alireza Ahmadyfard M. R. Mosavi
        In this paper, a new method is presented for the detection of defects in random textures. In the training stage, the feature vectors of the normal textures’ images are extracted by using the optimal response of Gabor wavelet filters, and their probability density چکیده کامل
        In this paper, a new method is presented for the detection of defects in random textures. In the training stage, the feature vectors of the normal textures’ images are extracted by using the optimal response of Gabor wavelet filters, and their probability density is estimated by means of the Gaussian Mixture Model (GMM). In the testing stage, similar to the previous stage,at first, the feature vectors corresponding to local neighborhoods of each pixel of the image under inspection are extracted. Then, by computing the likelihood of the test image’s feature vectors’ belonging to the parameters of the GMM, they are compared with a threshold value. Finally, the defective regions are localized in a defect map. The proposed algorithm was evaluated on a set of grayscale ceramic tile images with random textures. The simulations indicate that in comparison with the previous methods, the proposed algorithm enjoys an acceptable computational volume and accuracy in the detection of texture defects. پرونده مقاله
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        7 - Presenting a New Text-Independent Speaker Verification System Based on Multi Model GMM
        Mohammad Mosleh Faraz Forootan Najmeh Hosseinpour
        Speaker verification is the process of accepting or rejecting claimed identity in terms of its sound features. A speaker verification system can be used for numerous security systems, including bank account accessing, getting to security points, criminology and etc. Whe چکیده کامل
        Speaker verification is the process of accepting or rejecting claimed identity in terms of its sound features. A speaker verification system can be used for numerous security systems, including bank account accessing, getting to security points, criminology and etc. When a speaker verification system wants to check the identity of individuals remotely, it confronts problems such as noise effect on speech signal and also identity falsification with speech synthesis. In this system, we have proposed a new speaker verification system based on Multi Model GMM, called SV-MMGMM, in which all speakers are divided into seven different age groups, and then an isolated GMM model for each group is created; instead of one model for all speakers. In order to evaluate, the proposed method has been compared with several speaker verification systems based on Naïve, SVM, Random Forest, Ensemble and basic GMM. Experimental results show that the proposed method has so better efficiency than others. پرونده مقاله