Science in the Indian Universities     

Rais Ahmed  Madhulika Rakesh 《Minerva》1992,30(1):51-61

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Negotiating Academic Learning and Research: The Spiritual Praxis of Graduate Students of Color     

Riyad Ahmed Shahjahan  Lara Barker 《Equity & Excellence in Education》2013,46(4):456-472

Drawing on data collected in a qualitative study of racially minoritized faculty members, this article examines the challenges these faculty members faced in bringing different aspects of their spirituality into their scholarly work as graduate students. This article explores the questions: How do racially minoritized graduate students negotiate their spiritual identities and integrate their spiritual epistemologies and cultural knowledge into academic practices, and what challenges do they face in doing both? This article presents three salient themes: sacred subjectivity in student-focused research, spiritual praxis in the classroom, and new visions for inclusive spiritual expression in the academy. By focusing our analysis on study participants' strategies for resisting pressures to closet their beliefs, this article affirms the importance of legitimizing the spiritual epistemological perspectives of racially minoritized graduate students in creating a more equitable and diverse higher education culture.  相似文献   

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   

Observer based leader-following consensus of second-order multi-agent systems with nonuniform sampled position data     

Syed Ali Ajwad  Tomas Ménard  Emmanuel Moulay  Michael Defoort  Patrick Coirault 《Journal of The Franklin Institute》2019,356(16):10031-10057

This paper deals with the leader-following consensus problem of multi-agent systems with the consideration that each agent can only transmit its position state to the neighbors at irregular discrete sampling times. In the proposed algorithm, a continuous-discrete time observer is designed for the continuous estimation of both position and velocity from the discrete position information of the neighbors. These estimated states are then used for designing a continuous control law which solves the leader-following consensus problem. Moreover, the dynamics of the leader is not fixed and can be controlled through an external input. The stability analysis has been carried out by employing the Lyapunov approach which provides sufficient conditions to tune the parameters according to the maximum allowable sampling period. The developed algorithm has been simulated and then tested on an actual multi-robot system consisting of three differential drive wheeled robots. Both simulation and hardware results validate the effectiveness of the control algorithm.  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   

A conceptual model of taste receptors     

Syed Shamil B.Sc.  Ph.D.  C.Chem.  M.R.S.C.  M.I.F.S.T.  Gordon G. Birch B.Sc.  Ph.D.  D.Sc.  F.R.C.S.  F.I.F.S.T. 《Endeavour》1990,14(4)

Of all the senses, that of taste is perhaps the hardest to define and quantify and elucidation of the underlying mechanisms is unrespondingly difficult. This article describes a conceptual model — at the molecular level — for the four basic taste modalities, using apparent specific volume as a fundamental parameter. It also considers possible practical applications.  相似文献   

Book reviews     

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

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