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Search Results: 1 - 10 of 74 matches for " Chakib Marrakchi "
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Rubella associated with hemophagocytic syndrome. First report in a male and review of the literature
Makram Koubaa,Chakib Marrakchi,Imed Maaloul,Saloua Makni
Mediterranean Journal of Hematology and Infectious Diseases , 2012, DOI: 10.4084/mjhid.2012.
Abstract: A 22-year-old man was admitted to our hospital because of fever, skin rash and epistaxis. Physical examination revealed fever (39.5°C), generalized purpura, lymphadenopathy and splenomegaly. Blood tests showed pancytopenia. Bone marrow aspiration and biopsy showed hemophagocytosis with no evidence of malignant cells. Anti rubella IgM antibody were positif and the IgG titers increased from 16 to 50 UI/mL in 3 days. Therefore, he was diagnosed to have rubella-associated hemophagocytic syndrome. We report herein the first case in a man and the sixth case of rubella-associated hemophagocytic syndrome in the literature by search in Pub Med till March 2012.
Acoustic measures of the cry characteristics of healthy newborns and newborns with pathologies  [PDF]
Yasmina Kheddache, Chakib Tadj
Journal of Biomedical Science and Engineering (JBiSE) , 2013, DOI: 10.4236/jbise.2013.68097
Abstract: Several hypotheses have been formulated as a result of observing spectrograms of the audio signals of the newborn infant cry in numerous studies. Our study is based on a few of these hypotheses. The purpose of this article is to differentiate pathological crying from healthy crying through acoustic cry analysis based on neurophysiological parameters of newborns. The automatic estimation of the characteristics of relevant cry signals, such as phonation, hyperphonation, and dysphonation, expressed as percentages, as well as unvoiced sound and mode change percentages, have enabled us to distinguish among the pathologies selected for this study. The results obtained have helped us to make quantitative associations between cry characteristics and pathological conditions affecting newborns.

Characterization of Pathologic Cries of Newborns Based on Fundamental Frequency Estimation  [PDF]
Yasmina Kheddache, Chakib Tadj
Engineering (ENG) , 2013, DOI: 10.4236/eng.2013.510B057
Abstract:

The majority of the sick babies seem in good health at birth and early diagnosis of the various pathologies that can afflict newborn is crucial. For this reason we introduce in this paper the use of the fundamental frequency and the different modes of cries as Hyper-phonation, phonation and high pitched cries to differentiate the pathological cries from the cries of the healthy babies. The automatic estimation of these characteristics enabled us to establish a quantitative characterization of healthy newborn cries and pathologic newborn cries. The results obtained agree with the spectrographic analysis carried out on the healthy and pathologic cries of the newborns.

Splitting of Gaussian Models via Adapted BML Method Pertaining to Cry-Based Diagnostic System  [PDF]
Hesam Farsaie Alaie, Chakib Tadj
Engineering (ENG) , 2013, DOI: 10.4236/eng.2013.510B058
Abstract:

In this paper,we make use of the boosting method to introduce a new learning algorithm for Gaussian Mixture Models (GMMs) called adapted Boosted Mixture Learning (BML). The method possesses the ability to rectify the existing problems in other conventional techniques for estimating the GMM parameters, due in part to a new mixing-up strategy to increase the number of Gaussian components. The discriminative splitting idea is employed for Gaussian mixture densities followed by learning via the introduced method. Then, the GMM classifier was applied to distinguish between healthy infants and those that present a selected set of medical conditions. Each group includes both full-term and premature infants. Cry-pattern for each pathological condition is created by using the adapted BML method and 13-dimensional Mel-Frequency Cepstral Coefficients (MFCCs) feature vector. The test results demonstrate that the introduced method for training GMMs has a better performance than the traditional method based upon random splitting and EM-based re-estimation as a reference system in multi-pathological classification task.


SPECTRAL ANALYSIS OF BUCK AND SEPIC CONVERTERS
CHAKIB ALAOUI
International Journal of Engineering Science and Technology , 2011,
Abstract: Switched mode power converters generate harmonic currents, which will be injected into the utility grid, causing distortion of the utility waveform. They also become a source for the generation of EMI, which may affect the communication systems. This work is about the design and evaluation of the two most frequently used SMPS used in step down mode of operation: the Buck converter and the Sepic converter working in step-down mode of operation. These converters were designed using optimized equations for their components ratings. Simulation results show that although the Buck output voltage is low in harmonics, it has high harmonic contents in currents circulating in its inductor and diode, and hence requires strong filtering. The Sepic converterhas lower harmonic contents than the Buck converter.
Peltier Thermoelectric Modules Modeling and Evaluation
Chakib Alaoui
International Journal of Engineering , 2011,
Abstract: The purpose of this work is to develop and experimentally test a model for the Peltier effect heatpump for the transient simulation in Spice software. The proposed model uses controlled sourcesand lumped components and its parameters can be directly calculated from the manufacturer’sdata-sheets. In order to validate this model, a refrigeration chamber was designed and fabricatedby using the Peltier modules. The overall system was experimentally tested and simulated withSpice. The simulation results were found to be compatible with the experimental results. Thismodel will help designers to better design thermal systems using the Peltier modules.
Design and Simulation of a Modified Architecture of Carry Save Adder
Chakib Alaoui
International Journal of Engineering , 2011,
Abstract: This paper presents a technology-independent design and simulation of a modified architecture ofthe Carry-Save Adder. This architecture is shown to produce the result of the addition fast and byrequiring a minimum number of logic gates. Binary addition is carried out by a series of XOR,AND and Shift-left operations. These operations are terminated with a completion signalindicating that the result of the addition is obtained. Because the number of shift operationscarried out varies from 0 to n for n-bit addends, a behavioral model was developed in which allthe possible addends having 2- to 15-bits were applied. A mathematical model was deductedfrom the data and used to predict the average number of shift required for standard binarynumbers such as 32, 64 or 128-bits. 4-bit prototypes of this adder were designed and simulatedin both synchronous and asynchronous modes of operation.
TESTING AND SIMULATION OF SOLID STATE HEATING AND COOLING
CHAKIB ALAOUI
International Journal of Engineering Science and Technology , 2011,
Abstract: The latest model of solid state Peltier thermoelectric pumps was reviewed and improved. A heating-cooling chamber was designed and fabricated by using the Peltier modules, and its equivalent circuit was extracted and simulated. This chamber was tested under various values of input power in both cooling and heating modes of operations. The experimental results were compared with the proposed model. This model is proven to be accurate and can be extend to any Peltier based thermoelectric system for simulation, and can be used to simulated thermoelectric systems based on these modules.
The Moderating Role of Need for Personal Interaction in the Relationship between E-Quality, E-Satisfaction and Commitment “Case of Moroccan E-Banking Users”
Chakib HAMADI
IBIMA Business Review , 2011,
Abstract: This article demonstrates that the need for personal interaction has no moderating effect on the relationship between e-quality and e-satisfaction, either in the relationship between e-satisfaction and commitment. The results reveal that a high or low need for personal interaction does not modify these relationships for Moroccan e-banking users.
The Impact of Quality of Online Banking on Customer Commitment
Chakib Hamadi
Communications of the IBIMA , 2010,
Abstract: This article demonstrates the existence of a causal relationship between perceived quality, satisfaction and commitment in the context of online banking. The results show that the perceived quality heavily influences the commitment of customers and that this effect is direct and not mediated by satisfaction.
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