HMM has high power to describe complex phenomena. the Baum-Welch (BW) algorithm is very popular estimation method that use for estimating HMM model parameters but it start with an initial guess and finally converge to...
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HMM has high power to describe complex phenomena. the Baum-Welch (BW) algorithm is very popular estimation method that use for estimating HMM model parameters but it start with an initial guess and finally converge to a local optimum in practice. Chaos often exists in nonlinear systems. It has many good properties such as ergodicity, stochastic properties, regularity and high sensitivity to initial states. In this paper by use of these properties of chaos, an effective hybrid CHAOS-BW optimization method is proposed that uses the Chaos Optimization algorithm to optimize the initial values of Baum Welch algorithm. this algorithm not only overcomes the shortcoming of becoming trapped in local optimum of the BW algorithm, but is also fast and requires less storage than other hybrid optimization algorithms such as GABW, PSOBW and GAPSOBW. Experimental results on Persian digit dataset show that the propose method has both qualities of global search as well as rapid convergence. Comparison with several other more conventional approaches also reveals superior performance of the proposed model.
Membrane proteins play an important role in many biological processes and are attractive drug targets. In this study, membrane proteins are classified using two feature extraction and several classification strategies...
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Membrane proteins play an important role in many biological processes and are attractive drug targets. In this study, membrane proteins are classified using two feature extraction and several classification strategies. the first feature extraction strategy is pseudo amino acid (PseAA) composition; utilizing hydrophobicity and hydrophilicity for reflecting the sequence order effects, while the second method is discrete wavelet analysis (DWT); analyzing the different components of a signal localized both in space and scale domains. the nearest neighbor, probabilistic neural network, support vector machine, random forest, and Adaboost are used as basic learning mechanisms. the predicted results of the base learners are combined using majority voting to form an ensemble classifier. the best accuracy obtained for the Jackknife and independent dataset test is 85.4% and 95.3%, respectively. Using performance measures such as MCC, Sensitivity, Specificity, and F-measure, it has been observed that PseAA based prediction is significantly higher than that of the DWT, and is also the best reported, so far.
Electroencephalographic (EEG) technology has enabled effective measurement of human brain activity, as functional and physiological changes within the brain may be registered by EEG signals. In this paper, electrical ...
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ISBN:
(纸本)9781424471218;9781424471225
Electroencephalographic (EEG) technology has enabled effective measurement of human brain activity, as functional and physiological changes within the brain may be registered by EEG signals. In this paper, electrical activity of human brain due to sound waves of different frequency, i.e. 40 Hz, 500 Hz, 5000 Hz and 15000 Hz, is studied based on EEG signals. Several signal processing techniques, i.e. Principle Component algorithm, discrete Wavelet Transform and Fast Fourier Transform, are applied onto the raw EEG signal to extract useful information and specific characteristics from the EEG signals. this research has shown that the characteristics of EEG signals differ with respect to different frequency of sound waves, and hence the EEG signal can be identified with suitable characterization algorithm using artificial intelligent techniques, such as Artificial neural network, fuzzy logic and adaptive neuro-fuzzy system.
the development of mobile network technology provides a great potential for social networking services. this paper studied data mining for social network analysis purpose, which aims at find people's social networ...
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the development of mobile network technology provides a great potential for social networking services. this paper studied data mining for social network analysis purpose, which aims at find people's social network patterns by analyzing the information about their mobile phone usage. In this research, the real database of MIT's Reality Mining project is employed. the classification model presented in this project provides a new approach to find the proximity between users - based on their registration frequencies to specific cellular towers associated their working places. K-means Algorithm is applied for clustering, and we find the result could achieve the highest accuracy 0.823 at the number groups k = 6. the clustering result successfully reflects the higher proximity (at work) for the intra-class subjects.
Problems of multi-dimensional signal enhancement, segmentation, feature extraction and components classification is essential in many engineering and biomedical applications. the paper is devoted to the use of watersh...
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Problems of multi-dimensional signal enhancement, segmentation, feature extraction and components classification is essential in many engineering and biomedical applications. the paper is devoted to the use of watershed transform and wavelet transform for MR image components detection and discussion of over-segmentation problems. the goal of the paper is in (i) analysis of image de-noising, (ii) discussion of image enhancement, and (iii) multi-resolutional approach application for reduction of over-segmentation problems. Proposed algorithms include the use of wavelet transform and gradient methods in the preprocessing stage and application of the watershed transform for enhanced images. Resulting algorithms are verified for simulated images and applied for a selected MR biomedical images containing different structures.
the GIIDA project aims to develop a digital infrastructure for the spatial information within CNR. It is foreseen to use semantic-oriented technologies to ease information modeling and connecting, according to interna...
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While connected arithmetic discrete lines are entirely characterized, only partial results exist for the more general case of arithmetic discrete hyperplanes. In the present paper, we focus on the three-dimensional ca...
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While connected arithmetic discrete lines are entirely characterized, only partial results exist for the more general case of arithmetic discrete hyperplanes. In the present paper, we focus on the three-dimensional case. that is on arithmetic discrete planes. thanks to arithmetic reductions on a vector n, we provide algorithms either to determine whether a given arithmetic discrete plane with n as normal vector is connected, or to compute the minimal thickness for which an arithmetic discrete plane with normal vector n is connected. (c) 2008 Published by Elsevier B.V.
the paper considers a suboptimal solution to the dual control problem for discrete-time stochastic systems under the amplitude-constrained control signal. the objective of the control is to minimize the two-step quadr...
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ISBN:
(纸本)9789896740016
the paper considers a suboptimal solution to the dual control problem for discrete-time stochastic systems under the amplitude-constrained control signal. the objective of the control is to minimize the two-step quadratic cost function for the problem of tracking the given reference sequence. the presented approach is based on the MIDC (Modified Innovation Dual Controller) derived from an IDC (Innovation Dual Controller) and the TSDSC (Two-stage Dual Suboptimal Control. As a result, a new algorithm, i.e. the two-stage innovation dual control (TSIDC) algorithm is proposed. the standard Kalman filter equations are applied for estimation of the unknown system parameters. Example of second order system is simulated in order to compare the performance of proposed control algorithms. Conclusions yielded from simulation study are given.
discrete tomography deals withthe reconstruction of images from their projections where the images are assumed to contain only a small number of grey values. In particular, there is a strong focus on the reconstructi...
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discrete tomography deals withthe reconstruction of images from their projections where the images are assumed to contain only a small number of grey values. In particular, there is a strong focus on the reconstruction of binary images (binary tomography). A variety of binary tomography problems have been considered in the literature, each using different projection models or additional constraints. in this paper, we propose a generic iterative reconstruction algorithm that can be used for many different binary reconstruction problems. In every iteration, a subproblem is solved based on at most two of the available projections. Each of the subproblems can be solved efficiently using network flow methods. We report experimental results for various reconstruction problems. Our results demonstrate that the algorithm is capable of reconstructing complex objects from a small number of projections. (c) 2008 Elsevier B.V. All rights reserved.
the edge detection algorithms are important in biomedical image analysis. In this work, the histogram equalization and the discrete wavelet transform techniques were used to improve the quality of the gall bladder ult...
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ISBN:
(纸本)9789944898188
the edge detection algorithms are important in biomedical image analysis. In this work, the histogram equalization and the discrete wavelet transform techniques were used to improve the quality of the gall bladder ultrasonic images for edge detection. Also the median filtering algorithm was used after applying the both techniques. then the performances of the two algorithms were compared by several performance measures such as image entropy, paired t-test, and CPU time.
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