Adaptive T–S fuzzy controller using reinforcement learning based on Lyapunov stability

In this paper, an adaptive Takagi–Sugeno (T–S) fuzzy controller based on reinforcement learning for controlling the nonlinear dynamical systems is proposed. The parameters of the T–S fuzzy system are learned using the reinforcement learning based on the actor-critic method. This on-line learning algorithm improves the controller performance over the time, which it learns from its own faults through the reinforcement signal from the external environment and tries to reinforce the T–S fuzzy system parameters to converge. The updating parameters are developed using the Lyapunov stability criterion. The proposed controller is faster in learning than the T–S fuzzy that parameters learned using the gradient descent method under the same conditions. Moreover, it is able to handle the load changes and the system uncertainties. The test is carried out based on two mathematical models. In addition, the proposed controller is applied practically for controlling a direct current (DC) shunt machine. The results indicate that the response of the proposed controller has a good performance compared with other controllers.     

A composite pseudospectral method for solving multi-delay optimal control problems involving piecewise constant delay functions

An adaptive numerical method for solving multi-delay optimal control problems with piecewise constant delay functions is introduced. The proposed method is based on composite pseudospectral method using the well-known Legendre–Gauss–Lobatto points. In this approach, the main problem converts to a mathematical optimization problem whose solution is much more easier than the original one. The necessary conditions of optimality associated to nonlinear piecewise constant delay systems are derived. The method is easy to implement and provides very accurate results.     

Probabilistic fuzzy logic controller for uncertain nonlinear systems

This paper proposes a probabilistic fuzzy proportional - integral (PFPI) controller for controlling uncertain nonlinear systems. Firstly, the probabilistic fuzzy logic system (PFLS) improves the capability of the ordinary fuzzy logic system (FLS) to overcome various uncertainties in the controlled dynamical systems by integrating the probability method into the fuzzy logic system. Moreover, the input/output relationship for the proposed PFPI controller is derived. The resulting structure is equivalent to nonlinear PI controller and the equivalent gains for the proposed PFPI controller are a nonlinear function of input variables. These gains are changed as the input variables changed. The sufficient conditions for the proposed PFPI controller, which achieve the bounded-input bounded-output (BIBO) stability are obtained based on the small gain theorem. Finally, the obtained results indicate that the PFPI controller is able to reduce the effect of the system uncertainties compared with the fuzzy PI (FPI) controller.     

Evaluating the educational usability of Telegram as an SNS in ESAP programs from medical students’ perspective

This study aimed to investigate medical students’ evaluation of using Telegram as a Social Networking Site (SNS) in English for Specific Academic Purposes (ESAP) programs. To this end, the students’ explanatory responses about the merits and demerits of the SNS as well as their suggestions for improving its educational usability were collected. The qualitative data analysis of the students’ responses showed the merit codes of accessibility, data exchange, group learning, competitive atmosphere, peer-checking, and time-saving. The demerit codes emerging from the analysis were dependence and cheating, distrust, addiction, distraction, Internet problems, lack of supervision and lack of instruction. The codes derived from the students’ propositions were upgrading the SNS, dynamic atmosphere, blended-learning, teacher involvement, culture of using the platform, cooperative learning, appropriacy of the materials and type of the materials. The findings indicated that the trend of the students’ views about the merits of the site centered on technical categories, their views about the demerits of the system revolved mainly around behavioral categories and their propositions were closely linked to educational categories. The data analysis also showed significant differences in the perceived significance of the codes to the students with accessibility, Internet problems and type of the materials being the most prominent ones in the merit, demerit, and proposition codes respectively. From the findings, it can be concluded that educators should be encouraged to join the SNS to educationally support students, consider the merits and demerits of the SNS before employing it and improve the usability of the site based on the feedback they receive from students. The study suggests that a fine-tuned action plan be outlined with an eye to the technical, educational and behavioral requirements for using the SNS. It is also recommended that educators’ and students’ level and range of activities as well as ethical codes of conduct on the SNS be clearly stipulated in the course plan of programs involving the use of the site.     

Nonlinear model-predictive control with disturbance rejection property using adaptive neural networks

In this paper, a method is proposed to reject disturbances in the model predictive control (MPC) strategy. In addition, uncertainties in the system parameters (i.e., internal disturbances) are considered as well. To achieve these goals, adaptive neural networks are designed as the predictor model and as the nonlinear disturbance observer, respectively. The disturbances are rejected via the optimization problem of the MPC. Stability of the closed-loop system is studied based on the Input-to-State Stability method. The proposed method is applied to the pH neutralization process and CSTR system and its effectiveness in optimal rejection of the disturbances and satisfying the system constrains is compared with the feed-forward control method.     

The Shaffer–Gee perspective: Can epistemic games serve education?

This paper addresses the issue of how games can reshape education by describing current educational practices. It argues that there are conservative camps that emphasize structure and development of basic literacy and numeracy skills in education as well as liberal camps that emphasize immersion, and notices that both camps fail to train students able to address the crisis of innovation. A post-progressive pedagogy that integrates both structure and immersion to address this innovation crisis is described in the paper. It is also emphasized that epistemic games can serve as excellent tools at the hand of this post-progressive pedagogy.     

Isolation and purification of rat islet cells by flow cytometry

Flow cytometry has been employed as a method to study homogeneity of isolated islet subpopulations. After collagenase digestion of rat pancreas and elutriation of tissue fragments, islets were isolated and dissociated, and cells were analyzed and sorted according to their low forward angle light scattering properties by using automated flow cytometry. A standardized procedure was developed for the preparation of rat islet cell grafts for purification of islet cells. In this process, after collagenase digestion of pancreas, islets were isolated, dissociated, identification by dithizone method and then with enzymatic procedure by DNase and trypsin, the islet cells changed into single cells and beta cells were identified by immunofluorescence method and then assayed by flow cytometry. Methods have been developed for the preparation of suspension of viable rat pancreatic islet cells and their analysis and sorting in the fluorescence activated cell sorter (FACC IV, Becton Dickinson, Sunnyvale, Ca). Flow cytometry of these cells indicated that there were 91% of beta cells in cell suspension. Most of the exocrine particles were lost during digestion. Purified endocrine islet cell grafts were prepared by pure beta-cells, without endocrine non-beta cells. The purified aggregates were devoid of endocrine non-beta cells and damaged cells.     

The Uses and Gratifications of Language in Social Media among the Indian Subcontinental Diaspora in the U.S.

This study examines the uses and gratifications of language in social media among the Indian subcontinental diaspora in the United States, based on data collected from an online survey of 535 adult immigrants following a snowballing technique. Results showed the use of native language is related to the use of home country media, while the use of English language is related to emotional adjustment. This study contributes to the literature on social media, community, and language preference by opening avenues for conducting further research on the usage of language in social media among the Indian subcontinental diaspora in the United States. The findings of this study contribute to an understanding of the influence of social media on language preference.     

General Education Teachers in the United Arab Emirates and Their Acceptance of the Inclusion of Students with Disabilities

In this article, Dr Emad M. Alghazo and Dr Eman El. Naggar Gaad, both assistant professors at the Department of Special Education in the United Arab Emirates University, report on their research into the attitudes of mainstream teachers towards the inclusion of students with disabilities. The research took place in the Emirate of Abu-Dhabi, the capital of the United Arab Emirates, and set out to explore the extent to which general education teachers there accept the inclusion of students with disabilities in mainstream classrooms. The research process incorporated a questionnaire survey, analysed quantitatively, and a series of interviews with teachers to follow up on a range of issues. The analysis of the results takes account of a number of variables, including the gender of the respondents; number of years' experience as a teacher; and type of learner disability. Emad Alghazo and Eman Naggar Gaad report that there is more work to be done on the development of an 'inclusion culture' among teachers in the United Arab Emirates. They close their article by making a series of recommendations for future practice focusing on initial teacher education, continuing professional development and attitudinal change.