A new method for the extraction of fetal ECG from the dependent abdominal signals using blind source separation and adaptive noise cancellation techniques
Theoretical Biology and Medical Modelling, 2015
The electrocardiogram (ECG) is a diagnostic tool that records the electrical activity of the hear... more The electrocardiogram (ECG) is a diagnostic tool that records the electrical activity of the heart, and depicts it as a series of graph-like tracings, or waves. Being able to interpret these details allows diagnosis of a wide range of heart problems. Fetal electrocardiogram (FECG) extraction has an important impact in medical diagnostics during the mother pregnancy period. Since the observed FECG signals are often mixed with the maternal ECG (MECG) and the noise induced by the movement of electrodes or by mother motion, the separation process of the ECG signal sources from the observed data becomes quite complicated. One of its complexity is when the ECG sources are dependent, thus, in this paper we introduce a new approach of blind source separation (BSS) in the noisy context for both independent and dependent ECG signal source. This approach consist in denoising the observed ECG signals using a bilateral total variation (BTV) filter; then minimizing the Kullbak-Leibler divergence between copula densities to separate the FECG signal from the MECG one. We present simulation results illustrating the performance of our proposed method. We will consider many examples of independent/dependent source component signals. The results will be compared with those of the classical method called independent component analysis (ICA) under the same conditions. The accuracy of source estimation is evaluated through a criterion, called again the signal-to-noise-ratio (SNR). The first experiment shows that our proposed method gives accurate estimation of sources in the standard case of independent components, with performance around 27 dB in term of SNR. In the second experiment, we show the capability of the proposed algorithm to successfully separate two noisy mixtures of dependent source components - with classical criterion devoted to the independent case - fails, and that our method is able to deal with the dependent case with good performance. In this work, we focus specifically on the separation of the ECG signal sources taken from skin two electrodes located on a pregnant woman's body. The ECG separation is interpreted as a noisy linear BSS problem with instantaneous mixtures. Firstly, a denoising step is required to reduce the noise due to motion artifacts using a BTV filter as a very effective one-pass filter for denoising. Then, we use the Kullbak-Leibler divergence between copula densities to separate the fetal heart rate from the mother one, for both independent and dependent cases.
Technical Indexing of spatial database is discussed in this paper. Several methods of indexing mo... more Technical Indexing of spatial database is discussed in this paper. Several methods of indexing moving objects will be presented taking into account the faults and strengths of each one, the two main types of applications that manage moving objects will be discussed. "2-level index" is one of the recent variant indexing relied on R-tree, thereafter this variant will be presented and located between types of applications, its principle performance will be explained, the main defect which is redundancy of nodes after each update will be shown, and finally our contribution to optimize it will be presented.
Mobile devices leave a huge number of digital traces that are collected as trajectories, describi... more Mobile devices leave a huge number of digital traces that are collected as trajectories, describing the movement of its users or a path followed by any moving object in geographical space over some period of time. However, those mobile devices provide just raw trajectories (x, y, t), ignoring information about their related contextual data, these additional data contribute in producing significant knowledge about movements and provide applications with richer and more meaningful knowledge. Therefore, researchers focus on transforming raw trajectories into semantic trajectories by combining the raw mobility tracks with related contextual data and creating a new type of trajectories called "semantic trajectories", then applying mining techniques. This paper study closely the current researches on modeling and mining semantic trajectories so far, and try to investigate by proposing a descriptive schema including all steps that users can browse from the construction of the trajectories to the analyze of behaviors extracted.
International Journal of Computer Applications, 2015
Mobile devices leave a huge number of digital traces that are collected as trajectories, describi... more Mobile devices leave a huge number of digital traces that are collected as trajectories, describing the movement of its users or a path followed by any moving object in geographical space over some period of time. However, those mobile devices provide just raw trajectories (x, y, t), ignoring information about their related contextual data, these additional data contribute in producing significant knowledge about movements and provide applications with richer and more meaningful knowledge. Therefore, researchers focus on transforming raw trajectories into semantic trajectories by combining the raw mobility tracks with related contextual data and creating a new type of trajectories called "semantic trajectories", then applying mining techniques. This paper study closely the current researches on modeling and mining semantic trajectories so far, and try to investigate by proposing a descriptive schema including all steps that users can browse from the construction of the trajectories to the analyze of behaviors extracted.
2014 Second World Conference on Complex Systems (WCCS), 2014
Handwriting Arabic character recognition is one of the most challenging and complex tasks of rese... more Handwriting Arabic character recognition is one of the most challenging and complex tasks of research in Optical Character Recognition (OCR) and little research has been achieved in this area in the past few decades. This is due to the cursive nature of Arabic writing and the lack of public Arabic handwriting databases. In this paper, we present a general model of OCR system and an overview on several recently researches on offline handwriting Arabic character recognition systems. To evaluate the performance of these systems we compare their results using same database Benchmarking IFN/ENIT.
Numerical simulation of White–Metzner fluid in a 4:1 contraction
International Journal for Numerical Methods in Fluids, 2001
ABSTRACT A finite volume technique has been introduced in an attempt to simulate a viscoelastic f... more ABSTRACT A finite volume technique has been introduced in an attempt to simulate a viscoelastic flow. The steady flow of a White-Metzner fluid through a 4:1 abrupt contraction has been chosen as a prototype example because of the existence of previous simulations in the literature. The finite volume method (FVM) is used to discretize the conservation and constitute equations with a Hybrid scheme with appropriate treatment of source terms. The FVM is proven to be quite capable of handling numerically viscoelastic models with low computational cost. Its use is recommended as a viable alternative to the solution of viscoelastic problems using a variety of constitutive models. Copyright
A new method for the extraction of fetal ECG from the dependent abdominal signals using blind source separation and adaptive noise cancellation techniques
Theoretical Biology and Medical Modelling, 2015
The electrocardiogram (ECG) is a diagnostic tool that records the electrical activity of the hear... more The electrocardiogram (ECG) is a diagnostic tool that records the electrical activity of the heart, and depicts it as a series of graph-like tracings, or waves. Being able to interpret these details allows diagnosis of a wide range of heart problems. Fetal electrocardiogram (FECG) extraction has an important impact in medical diagnostics during the mother pregnancy period. Since the observed FECG signals are often mixed with the maternal ECG (MECG) and the noise induced by the movement of electrodes or by mother motion, the separation process of the ECG signal sources from the observed data becomes quite complicated. One of its complexity is when the ECG sources are dependent, thus, in this paper we introduce a new approach of blind source separation (BSS) in the noisy context for both independent and dependent ECG signal source. This approach consist in denoising the observed ECG signals using a bilateral total variation (BTV) filter; then minimizing the Kullbak-Leibler divergence between copula densities to separate the FECG signal from the MECG one. We present simulation results illustrating the performance of our proposed method. We will consider many examples of independent/dependent source component signals. The results will be compared with those of the classical method called independent component analysis (ICA) under the same conditions. The accuracy of source estimation is evaluated through a criterion, called again the signal-to-noise-ratio (SNR). The first experiment shows that our proposed method gives accurate estimation of sources in the standard case of independent components, with performance around 27 dB in term of SNR. In the second experiment, we show the capability of the proposed algorithm to successfully separate two noisy mixtures of dependent source components - with classical criterion devoted to the independent case - fails, and that our method is able to deal with the dependent case with good performance. In this work, we focus specifically on the separation of the ECG signal sources taken from skin two electrodes located on a pregnant woman's body. The ECG separation is interpreted as a noisy linear BSS problem with instantaneous mixtures. Firstly, a denoising step is required to reduce the noise due to motion artifacts using a BTV filter as a very effective one-pass filter for denoising. Then, we use the Kullbak-Leibler divergence between copula densities to separate the fetal heart rate from the mother one, for both independent and dependent cases.
Technical Indexing of spatial database is discussed in this paper. Several methods of indexing mo... more Technical Indexing of spatial database is discussed in this paper. Several methods of indexing moving objects will be presented taking into account the faults and strengths of each one, the two main types of applications that manage moving objects will be discussed. "2-level index" is one of the recent variant indexing relied on R-tree, thereafter this variant will be presented and located between types of applications, its principle performance will be explained, the main defect which is redundancy of nodes after each update will be shown, and finally our contribution to optimize it will be presented.
Mobile devices leave a huge number of digital traces that are collected as trajectories, describi... more Mobile devices leave a huge number of digital traces that are collected as trajectories, describing the movement of its users or a path followed by any moving object in geographical space over some period of time. However, those mobile devices provide just raw trajectories (x, y, t), ignoring information about their related contextual data, these additional data contribute in producing significant knowledge about movements and provide applications with richer and more meaningful knowledge. Therefore, researchers focus on transforming raw trajectories into semantic trajectories by combining the raw mobility tracks with related contextual data and creating a new type of trajectories called "semantic trajectories", then applying mining techniques. This paper study closely the current researches on modeling and mining semantic trajectories so far, and try to investigate by proposing a descriptive schema including all steps that users can browse from the construction of the trajectories to the analyze of behaviors extracted.
International Journal of Computer Applications, 2015
Mobile devices leave a huge number of digital traces that are collected as trajectories, describi... more Mobile devices leave a huge number of digital traces that are collected as trajectories, describing the movement of its users or a path followed by any moving object in geographical space over some period of time. However, those mobile devices provide just raw trajectories (x, y, t), ignoring information about their related contextual data, these additional data contribute in producing significant knowledge about movements and provide applications with richer and more meaningful knowledge. Therefore, researchers focus on transforming raw trajectories into semantic trajectories by combining the raw mobility tracks with related contextual data and creating a new type of trajectories called "semantic trajectories", then applying mining techniques. This paper study closely the current researches on modeling and mining semantic trajectories so far, and try to investigate by proposing a descriptive schema including all steps that users can browse from the construction of the trajectories to the analyze of behaviors extracted.
2014 Second World Conference on Complex Systems (WCCS), 2014
Handwriting Arabic character recognition is one of the most challenging and complex tasks of rese... more Handwriting Arabic character recognition is one of the most challenging and complex tasks of research in Optical Character Recognition (OCR) and little research has been achieved in this area in the past few decades. This is due to the cursive nature of Arabic writing and the lack of public Arabic handwriting databases. In this paper, we present a general model of OCR system and an overview on several recently researches on offline handwriting Arabic character recognition systems. To evaluate the performance of these systems we compare their results using same database Benchmarking IFN/ENIT.
Numerical simulation of White–Metzner fluid in a 4:1 contraction
International Journal for Numerical Methods in Fluids, 2001
ABSTRACT A finite volume technique has been introduced in an attempt to simulate a viscoelastic f... more ABSTRACT A finite volume technique has been introduced in an attempt to simulate a viscoelastic flow. The steady flow of a White-Metzner fluid through a 4:1 abrupt contraction has been chosen as a prototype example because of the existence of previous simulations in the literature. The finite volume method (FVM) is used to discretize the conservation and constitute equations with a Hybrid scheme with appropriate treatment of source terms. The FVM is proven to be quite capable of handling numerically viscoelastic models with low computational cost. Its use is recommended as a viable alternative to the solution of viscoelastic problems using a variety of constitutive models. Copyright
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