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Abdellatif Ben Makhlouf,Mohamed Ali Hammami 제어·로봇·시스템학회 2014 International Journal of Control, Automation, and Vol.12 No.6
In this paper, we point out that inequality (7) of [5] is not correct. A feasible modified and corrected version of the main result is presented. Furthermore, some numerical examples are given to illustrate the applicability of the modified result.
A variant of d'Alembert's and Wilson's functional equations for matrix valued functions
Abdellatif Chahbi,Mohamed Chakiri,Elhoucien Elqorachi 대한수학회 2024 대한수학회논문집 Vol.39 No.3
Given $M$ a monoid with a neutral element $e$. We show that the solutions of d'Alembert's functional equation for $n\times n$ matrices \begin{equation*} \Phi(pr,qs)+\Phi(sp,rq)=2\Phi(r,s)\Phi(p,q),\quad p,q,r,s\in M \end{equation*} are abelian. Furthermore, we prove under additional assumption that the solutions of the n-dimensional mixed vector-matrix Wilson's functional equation \begin{equation*} \left\lbrace\begin{array}{ll} f(pr,qs)+f(sp,rq)=2\Phi(r,s)f(p,q),\\ \Phi(p,q)=\Phi(q,p),\quad p,q,r,s\in M \end{array}\right. \end{equation*} are abelian. As an application we solve the first functional equation on groups for the particular case of $n=3$.
Stability of fractional-order nonlinear systems depending on a parameter
Abdellatif Ben Makhlouf,Mohamed Ali Hammami,Khaled Sioud 대한수학회 2017 대한수학회보 Vol.54 No.4
In this paper, we present a practical Mittag Leffler stability for fractional-order nonlinear systems depending on a parameter. A sufficient condition on practical Mittag Leffler stability is given by using a Lyapunov function. In addition, we study the problem of stability and stabilization for some classes of fractional-order systems.
Cervical Cancer in Morocco: Epidemiological Profile from Two Main Oncological Centers
Berraho, Mohamed,Bendahhou, Karima,Obtel, Majdouline,Zidouh, Ahmed,Benider, Abdellatif,Errihani, Hassan,Nejjari, Chakib Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7
Background: In Morocco, the epidemiological profile of cervical cancer is not well established. The focus of the present study was both epidemiological and pathological characteristics. Methods: For all cases of cervical cancer treated between 2003 and 2007 in the National Institute of Oncology and the Oncology Department of the IbnRochd hospital (Casablanca), 900 cases were randomly selected. Results: The mean age was $52.1{\pm}11.8$ years. The most (90.5%) represented histological type was squamous cell carcinoma. For more than 57.0% cases the mean distance between patient's origin and center of treatment was greater than 100km. According to the FIGO classification, only 17.2% of patients were identified as being in early stages (0 and I). For 72.2% patients the follow-up did not exceed 2 years. At 1 year of following-up 55.8% of patients were alive and 43.4% were lost to following-up. Conclusion: Our study addressed the issue of the burden of cervical cancer in Morocco. The result provides a basis for decision-makers for the development of strategic measures to implement the fight against cervical cancer in Morocco.
Inertia tensor estimation for a rigid nadir pointing satellite based on star tracker
Cheriet, Mohammed E.A.,Bellar, Abdellatif,Ghaffour, Mohammed Y.,Adnane, Akram,Mohammed, Mohammed A. SI Techno-Press 2021 Advances in aircraft and spacecraft science Vol.8 No.2
Accurate inertia properties information is important to reach an optimized estimation of attitude and precise control of a rigid spacecraft. Unfortunately, the satellite is succumbing several influences that can affect the inertia properties, such as fuel consumption and sloshing. Thus, this work inspects the use of star tracker to estimate the attitude, angular velocity and moment of inertia for a rigid nadir pointing satellite by employing extended Kalman filter, without any prior information about the nominal inertia matrix. The proposed estimator is applied in nadir pointing mode and without any constant control torque to avoid the attitude tumbling during the estimation phase, which in turn leads to a catastrophic failure of the satellite mission. The simulation results are compared to three other approaches and validated by Monte Carlo method that elucidates the good performance of the suggested approach and demonstrates its efficiency in satellite inertia tensor and attitude estimation even in worst situations.
Inertia tensor estimation for a rigid nadir pointing satellite based on star tracker
Cheriet, Mohammed E.A.,Bellar, Abdellatif,Ghaffour, Mohammed Y.,Adnane, Akram,Mohammed, Mohammed A. SI Techno-Press 2021 Advances in aircraft and spacecraft science Vol.8 No.2
Accurate inertia properties information is important to reach an optimized estimation of attitude and precise control of a rigid spacecraft. Unfortunately, the satellite is succumbing several influences that can affect the inertia properties, such as fuel consumption and sloshing. Thus, this work inspects the use of star tracker to estimate the attitude, angular velocity and moment of inertia for a rigid nadir pointing satellite by employing extended Kalman filter, without any prior information about the nominal inertia matrix. The proposed estimator is applied in nadir pointing mode and without any constant control torque to avoid the attitude tumbling during the estimation phase, which in turn leads to a catastrophic failure of the satellite mission. The simulation results are compared to three other approaches and validated by Monte Carlo method that elucidates the good performance of the suggested approach and demonstrates its efficiency in satellite inertia tensor and attitude estimation even in worst situations.
STABILITY OF FRACTIONAL-ORDER NONLINEAR SYSTEMS DEPENDING ON A PARAMETER
Ben Makhlouf, Abdellatif,Hammami, Mohamed Ali,Sioud, Khaled Korean Mathematical Society 2017 대한수학회보 Vol.54 No.4
In this paper, we present a practical Mittag Leffler stability for fractional-order nonlinear systems depending on a parameter. A sufficient condition on practical Mittag Leffler stability is given by using a Lyapunov function. In addition, we study the problem of stability and stabilization for some classes of fractional-order systems.
Frank Jochum,Mohamed Abdellatif,Ashraf Adel,Ahmed Alhammadi,Abdulrahman Alnemri,Eman Alohali,Khaled AlSarraf,Khoula Al-Said,Mahmoud Elzalabany,Hasan M. A. Isa,Sridhar Kalyanasundaram,Naguib Abdel Rehe 대한소아소화기영양학회 2022 Pediatric gastroenterology, hepatology & nutrition Vol.25 No.2
Adequate nutrition in early life is proposed to shape a child’s future health by launching the growth trajectory in the proper direction, which helps to avoid negative metabolic programming effects. Protein intake during infancy and early childhood is of great importance, as it plays a key role in infant metabolic programming and the future risk of obesity. Breastfeeding provides the best nutrition in early life, with many benefits tailored for the baby, including the appropriate quantity and quality of proteins. Considering the high prevalence of childhood, and subsequent adult, obesity in the region, a virtual Middle East expert consensus meeting was held to discuss an effective approach for managing childhood obesity. Leading pediatric experts from Bahrain, Egypt, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates participated in the meeting. The experts discussed, debated, and agreed on certain directions, including the importance of educating parents, endorsing breastfeeding, and ensuring optimum quantity and quality intake of proteins in early life. This expert consensus may serve as the starting point for healthcare professionals in the region who are interested in shaping a healthy future for the generations to come.
Akram Alaya,Abdellatif Nouri,Mohsen Belgith,Hammadi Saad,Riadh Jouini,Mohamed Fadhel Najjar 대한진단검사의학회 2012 Annals of Laboratory Medicine Vol.32 No.3
Background: Studies that evaluate the effect of age on stone composition are scarce. The aim of this study was to highlight the changes in epidemiological characteristics (stone composition and location) of urolithiasis according to patients’ age. Methods: We studied 1,301 urolithiasis patients with age ranging from 6 months to 92 yr (781 males and 520 females). Stone analysis was performed using a stereomicroscope and infrared spectroscopy to determine the morphological type and molecular composition of each stone. Results: The annual average incidence of new stone formation was 31.7 per 100,000 persons. In 71.8% of cases, calculi were located in the upper urinary tract. Compared to other age groups, children and old men were more affected by bladder stones. Calcium oxalate monohydrate was the most frequent stone component, even though its frequency decreased with age (59.5% in young adults and 43.7% in the elderly, P<0.05) in favor of an increase in uric acid stones (11.5% in young adults and 36.4% in the elderly, P<0.05). Struvite stones were rare (3.8%) and more frequent in children than in adults. Conclusions: The analysis of these data showed that urinary stones in Tunisian patients are tending to evolve in the same direction as the stones in patients from industrialized countries. Background: Studies that evaluate the effect of age on stone composition are scarce. The aim of this study was to highlight the changes in epidemiological characteristics (stone composition and location) of urolithiasis according to patients’ age. Methods: We studied 1,301 urolithiasis patients with age ranging from 6 months to 92 yr (781 males and 520 females). Stone analysis was performed using a stereomicroscope and infrared spectroscopy to determine the morphological type and molecular composition of each stone. Results: The annual average incidence of new stone formation was 31.7 per 100,000 persons. In 71.8% of cases, calculi were located in the upper urinary tract. Compared to other age groups, children and old men were more affected by bladder stones. Calcium oxalate monohydrate was the most frequent stone component, even though its frequency decreased with age (59.5% in young adults and 43.7% in the elderly, P<0.05) in favor of an increase in uric acid stones (11.5% in young adults and 36.4% in the elderly, P<0.05). Struvite stones were rare (3.8%) and more frequent in children than in adults. Conclusions: The analysis of these data showed that urinary stones in Tunisian patients are tending to evolve in the same direction as the stones in patients from industrialized countries.