Lag projective synchronization of fractional-order delayed chaotic systems     

Weiwei Zhang  Jinde Cao  Ranchao Wu  Fuad E. Alsaadi  Ahmed Alsaedi 《Journal of The Franklin Institute》2019,356(3):1522-1534

This paper considers the lag projective synchronization of fractional-order delayed chaotic systems. The lag projective synchronization is achieved through the use of comparison principle of linear fractional equation at the presence of time delay. Some sufficient conditions are obtained via a suitable controller. The results show that the slave system can synchronize the past state of the driver up to a scaling factor. Finally, two different structural fractional order delayed chaotic systems are considered in order to examine the effectiveness of the lag projective synchronization. Feasibility of the proposed method is validated through numerical simulations.  相似文献   

Stabilization of artificial gas-lift process using nonlinear predictive generalized minimum variance control     

Jing Shi  Ahmed Al-Durra  Rachid Errouissi  Igor Boiko 《Journal of The Franklin Institute》2019,356(4):2031-2059

Artificial gas-lift (AGL) is one of the most widely used methods in oil production to maintain acceptable oil flow to the processing equipment and sales when the reservoir pressure is not high enough. In spite of its popularity, the AGL process is prone to casing-heading instability, which is revealed as significant flow oscillation. This is undesirable as it results in production losses and unstable behavior that has negative impact on the downstream equipment. Controller design for such a process is very challenging as it exhibits highly nonlinear dynamics. In this work, the predictive generalized minimum variance control (NPGMV) is employed to derive a robust controller based on the state estimation to stabilize AGL process when casing-heading phenomenon occurs. A closed-form optimal control law is obtained based on the Taylor series approximation. Further, a nonlinear state observer is produced and combined with the controller to ensure closed-loop control through variables that are most beneficial to the system performance, which are unmeasurable and can be obtained only via estimation. Through simulation studies, the effectiveness of the proposed controller is demonstrated.  相似文献   

New modeling approach of secondary control layer for autonomous single-phase microgrids     

Ahmed Bendib  Aissa Chouder  Kamel Kara  Abdelhammid Kherbachi  Said Barkat  Walid Issa 《Journal of The Franklin Institute》2019,356(13):6842-6874

In a microgrid (MG) topology, the secondary control is introduced to compensate for the voltage amplitude and frequency deviations, mainly caused by the inherent characteristics of the droop control strategy. This paper proposes an accurate approach to derive small signal models of the frequency and amplitude voltage at the point of common coupling (PCC) of a single-phase MG by analyzing the dynamics of the second-order generalized integrator-based frequency-locked loop (SOGI-FLL). The frequency estimate model is then introduced in the frequency restoration control loop, while the derived model of the amplitude estimate is introduced for the voltage restoration loop. Based on the obtained models, the MG stability analysis and proposed controllers’ parameters tuning are carried out. Also, this study includes the modeling and design of the synchronization control loop that enables a seamless transition from island mode to grid-connected mode operation. Simulation and practical experiments of a hierarchical control scheme, including traditional droop control and the proposed secondary control for two single-phase parallel inverters, are implemented to confirm the effectiveness and the robustness of the proposal under different operating conditions. The obtained results validate the proposed modeling approach to provide the expected transient response and disturbance rejection in the MG.  相似文献   

Dynamics of a stochastic multigroup SIQR epidemic model with standard incidence rates     

Qun Liu  Daqing Jiang  Tasawar Hayat  Ahmed Alsaedi 《Journal of The Franklin Institute》2019,356(5):2960-2993

In this paper, we consider a stochastic multigroup SIQR epidemic model with standard incidence rates. By using the stochastic Lyapunov function method, we establish sufficient conditions for the existence of a stationary distribution of the positive solutions to the model. Then we establish sufficient conditions for extinction of the diseases. A stationary distribution means that all the individuals can be coexistent and persistent in the long term. Finally, some examples and numerical simulations are introduced to illustrate our theoretical results.  相似文献   

Integrating design science research and design based research frameworks for developing education support systems     

Fahd  Kiran  Miah  Shah J.  Ahmed  Khandakar  Venkatraman  Sitalakshmi  Miao  Yuan 《Education and Information Technologies》2021,26(4):4027-4048

Education and Information Technologies - This paper proposes an integrated research framework that takes advantage of the similarities of design science research (DSR) and Design-based research...  相似文献   

Book reviews     

Manzoor Ahmed  Myriam Bacquemaine 《Prospects》1987,17(1):149-157

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Assessing the Emotional Intelligence of Gifted and Talented Adolescent Students in the Kingdom of Bahrain     

Najat Sulaiman Al-Hamdan  Fatima Ahmed Al-Jasim  Ahmed M. Abdulla 《Roeper Review》2017,39(2):132-142

This study assessed the differences in the emotional intelligence of gifted adolescent students and talented adolescent students in Bahrain. The sample consisted of 80 gifted adolescent students and 80 talented adolescent students in Grades 9 through 12. A multivariate analysis of variance (MANOVA) indicates that there were significant differences in emotional intelligence levels, as measured by the Bar-On Emotional Quotient Inventory, between gifted students and talented students in Bahrain in the direction of gifted students. There were differences between the gifted and the talented students in intrapersonal, adaptability, general mood subtest, and total emotional intelligence scores. Finally, gifted males had higher total emotional intelligence scores than gifted females; talented females had higher interpersonal scores than talented males.  相似文献   

The challenge of basic education for all     

Manzoor Ahmed  Gabriel Carron 《Prospects》1989,19(4):559-572

UNICEF Representative in China. Author of several books and articles ou non-formal education, rural development and educational planning.  相似文献   

Views of Omani post-basic education students about religious and cultural tolerance     

Ahmed Hamad Al-Rabaani 《Cambridge Journal of Education》2018,48(1):87-101

The study aims to investigate the views of Omani post-basic education students (Grades 10–12) about religious and cultural tolerance. The sample consisted of 1390 male and female students in grades 10, 11 and 12, from four of Oman’s seven regions. A questionnaire was used to gather data, which consisted of 27 items divided into five domains. The results showed that students place a strong emphasis on the importance of religious and cultural tolerance, both within Oman society and worldwide. They are also not in favour of any type of aggression, religious and cultural symbols or the fuelling of disagreements between religions or cultures. The results also indicated that female students are more strongly concerned with tolerance than males, grade 12 students more concerned than those in grades 10 and 11, and students from Muscat more concerned than those in other less urban areas.  相似文献   

Principals' and teachers' attitudes and knowledge of inclusive education as predictors of effective teaching practices in Ghana     

Ahmed Bawa Kuyini  Ishwar Desai 《Journal of Research in Special Educational Needs》2007,7(2):104-113

Surveys and observations were undertaken in selected primary schools in Ghana to determine whether principals' and teachers' attitudes towards and knowledge of inclusive education, as well as principals' expectations of teachers in implementing inclusion, were predictors of effective teaching practices in their classrooms. The sample of 128 educators (20 principals and 108 teachers) drawn from 20 primary schools in two districts, were required to respond to questionnaire measures of Attitude Towards Inclusive Education Scale (ATIES), Knowledge of Inclusive Education Scale (KIES) and Principals' Expectations Scale (PES). Of the total number of teachers ( N  = 108), 37 were observed during instructional delivery in their classrooms. The data were analysed by a variety of statistical procedures including Regression Analysis and Discriminant Function Analysis. In the context of the Theory of Planned Behaviour (Ajzen, 1985), the results showed that whilst attitudes towards inclusion (attitude element) and knowledge of inclusion (perceived behavioural control element) predicted effective teaching practices, principals' expectations (subjective norm) did not. Implications for the implementation of effective inclusive practices in Ghanaian schools and the need for future research are discussed.  相似文献