Rihab Bkekri, Anouar Benamor, Mohamed Amine Alouane, Georges Fried and Hassani Messaoud
Assistive technology products are designed to provide additional accessibility to individuals who have physical or cognitive difficulties, impairments and disabilities. The…
Abstract
Purpose
Assistive technology products are designed to provide additional accessibility to individuals who have physical or cognitive difficulties, impairments and disabilities. The purpose of this paper is to deal with the control of a knee joint orthosis intended to be used for rehabilitation and assistive purpose; this control aims to reduce the influence of the uncertainties and eliminating the external disturbances in the system.
Design/methodology/approach
This paper deals with the robust adaptive sliding mode controller (ASMC) of human-driven knee joint orthosis system with mismatched uncertainties and external disturbances. The shank-orthosis system has been modeled and its parameters have been identified. This control reduces the effect of parameter uncertainties and external disturbances on the system performance and improves the system robustness as results. The ASMC was designed to offer the possibility to track the state of the reference model. Moreover, the Lyapunov stability theory was used to study the asymptotical stability of the ASMC.
Findings
The advantage of the robust ASMC method is the tracking precision and reducing the required time for eliminating external disturbances and uncertainties. The experimental results show in real-time in terms of stability and present that the advantages of this control approach are the position tracking and robustness.
Originality/value
In this paper, to deal with the parameter uncertainties of the human-driven knee joint orthosis, an ASMC was successfully applied based on sliding mode and Lyapunov stability theory. It has good dynamic response and tracking performance. Besides, the adaptive algorithm is simple, easy to achieve and has good adaptability and robustness against the parameter variations and external disturbances. The design technique is simple and efficient. The development of this control takes into consideration the perturbation, allowing to track a desired trajectory.
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Rihab Bkekri, Anouar Benamor, Mohamed Amine Alouane, Georges Fried and Hassani Messaoud
The application of the sliding mode control has two obstacle phenomena: chattering and high activity of control action. The purpose of this paper concerns a novel super-twisting…
Abstract
Purpose
The application of the sliding mode control has two obstacle phenomena: chattering and high activity of control action. The purpose of this paper concerns a novel super-twisting adaptive sliding mode control law of a human-driven knee joint orthosis. The proposed control approach consists of using dynamically adapted control gains that ensure the establishment, in a finite time, of a real second-order sliding mode. The efficiency of the controller is evaluated using an experimental set-up.
Design/methodology/approach
This study presents the synthesis of a robust super-twisting adaptive controller for the control of a lower limb–orthosis system. The developed control strategy will take into consideration the nonlinearities as well as the uncertainties resulting from the dynamics of the lower limb–orthosis system. It must also guarantee a good follow-up of the reference trajectory.
Findings
The authors first evaluated on a valid subject, the performances of this controller which were studied and compared to several criteria. The obtained results show that the controller using the Adaptive Super-Twisting algorithm is the one that guarantees the best performance. Validation tests involved a subject and included robustness tests against external disturbances and co-contractions of antagonistic muscles.
Originality/value
The main contribution of this paper is in developing the adaptation super-twisting methodology for finding the control gain resulting in the minimization of the chattering effect.
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Steve D. Mobley, Nina Daoud and Kimberly A. Griffin
While many may assume that all students enrolled at historically Black campuses are African American, recent trends suggest these campuses are becoming increasingly diverse. In…
Abstract
While many may assume that all students enrolled at historically Black campuses are African American, recent trends suggest these campuses are becoming increasingly diverse. In this chapter, we challenge common perceptions about historically Black colleges and universities (HBCUs), highlighting both what is known and yet to be known about enrollment trends and the experiences of students from diverse backgrounds at historically Black campuses. The chapter presents data from the National Center for Education Statistics, tracking changes in enrollments over time. These data are coupled with a review of research on the experiences of non-Black students at HBCUs, largely focusing on White students, but also integrating the narratives of a growing Latina/o/x student population. HBCUs can also be ethnically diverse, and we examine the heterogeneity within the Black student experience based on ethnic identity and immigrant status. We close with recommendations for research and practice, calling for increased attention to how non-Black populations experience, navigate, and engage HBCU campus communities to promote student outcomes and opportunities for learning across difference.
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Ramon B. Goings, Travis J. Bristol and Larry J. Walker
There is limited discussion in the teacher education literature about the experiences of pre-service black male teachers generally and the ethnic diversity among black male…
Abstract
Purpose
There is limited discussion in the teacher education literature about the experiences of pre-service black male teachers generally and the ethnic diversity among black male pre-service teachers specifically. Thus, this paper aims to explore the experiences of Frank, a black male refugee health education major attending an historically black college and university (HBCU).
Design/methodology/approach
This research study is theoretically guided by selected tenets of Bush and Bush’s (2013) African American male theory and Goodman et al.’s (2006) transition framework and uses a qualitative approach to explore Frank’s transition experiences when coming to America, attending college and engaging in his student teaching experience.
Findings
Frank experienced some difficulty transitioning to America, as a result of not having a strong financial foundation. During his college transition, Frank believed that the HBCU environment was nurturing; however, he encountered numerous ethnocentrically charged hostile confrontations from US-born black students at his university because of his accent. While he had some disagreements with the US education system in terms of discipline, Frank believed that his accent served as an asset during student teaching.
Originality/value
This study adds to the burgeoning research that explores the intersectional identities among pre-service black male teachers. As we argue in this paper, researchers, policymakers and practitioners cannot treat black male teachers as a monolithic group and must contemplate the unique supports needed that can attend to the racial and ethnic needs of black male teachers.
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This Society, originally known as “The National Pure Food Association,” has been reconstituted under the above title. The objects of the Society are to assist as far as possible…
Abstract
This Society, originally known as “The National Pure Food Association,” has been reconstituted under the above title. The objects of the Society are to assist as far as possible in checking the widespread evils of food adulteration, for this purpose to bring about a public realisation of the admittedly serious character of food frauds, and, under expert advice, to co‐operate with constituted authority in effecting their repression. The policy of the Society is directed by a representative Council, and, the Society being thus established on an authoritative basis, cannot fail to become a powerful and valuable organisation if adequately and generously supported by the public. The governing body of the Society is constituted as follows:—
Mohamed E. Lalami, Hala Rifaï, Samer Mohammed, Walid Hassani, Georges Fried and Yacine Amirat
– The purpose of this paper is the control of lower limb orthosis acting at the knee joint level for a passive rehabilitation purpose.
Abstract
Purpose
The purpose of this paper is the control of lower limb orthosis acting at the knee joint level for a passive rehabilitation purpose.
Design/methodology/approach
A control law, based on a saturated proportional derivative controller, is proposed in order to drive the shank-foot-orthosis system along a desired trajectory.
Findings
The proposed control law is tested in real time using the orthosis EICOSI of the LISSI-Laboratory. The experiments show that the proposed control law is capable of providing satisfactory trajectory tracking performance given only the knee joint angle measurement. Moreover, the control law is robust with respect to external disturbances.
Originality/value
Robust control of an actuated lower limb orthosis.
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Meseret F. Hailu and Maima Chea Simmons
The educational experiences of Black immigrant women in P-16 education are often understudied in critical scholarship about race, ethnicity, and gender. The existing literature on…
Abstract
The educational experiences of Black immigrant women in P-16 education are often understudied in critical scholarship about race, ethnicity, and gender. The existing literature on Black students in US higher education tends to overlook within-group diversity, oftentimes highlighting the experience of domestically born African Americans and neglecting the experiences of Black people born outside of the country. To address this gap in the education discourse, we examined the experiences of Black, African immigrant girls and women who have experienced all or part of their P-16 education in the United States. Using a combination of Critical Race Feminism (CRF) and transnationalism as our theoretical frameworks, we sought to answer two research questions: (1) How do Black immigrant women in the film describe their process of racial, ethnic, and gender identity formation? and (2) What are the literacy practices and educational experiences of Black African girls and women? Methodologically, we drew from Saldaña's (2009) model of film-based qualitative inquiry to analyze the documentary Am I: Too African to be American or Too American to be African? (directed by Dr Nadia Sasso). In our analysis, we foreground the lived experiences of eight women from three African countries: Nigeria, Sierra Leone, and Senegal. Major findings from this qualitative analysis include: (1) the importance of cultural negotiation for immigrant girls and women, (2) the presence of dualities in language and ways of speaking in education, (3) a tumultuous racial identity formation process, and (4) the linked perceptions of students' gender identity and beauty. Finally, we present implications for immigration policy, inclusive research, and equitable practice across P-16 education.
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This chapter introduces the tenets of international student critical race theory (IntlCrit) by expanding the critical race methodology to better account for the racialized…
Abstract
This chapter introduces the tenets of international student critical race theory (IntlCrit) by expanding the critical race methodology to better account for the racialized experiences of international students of color (SOC) in higher education. IntlCrit emphasizes recognizing international SOC as a racialized student body and acknowledges international students' different racial contexts and experiences in their home countries beyond the US dominant monolithic paradigm of racism (Black and White). IntlCrit provides a conceptual foundation for scholarly discourse on race and racism by offering a set of tailored tenets while utilizing tenets of critical race theory (CRT). The tailored tenets can further advance critical analyses to examine developmental processes of racial “othering” and understand the ways that racism affects international SOC in the internationalization of higher education. The IntlCrit tenets include: recognizing and humanizing international SOC as a racial body; evolving international students' eyes (racial identity development); acknowledging intersectional and transnational identities; using an expansive and inclusive historical approach; centering race and racism on international students' experiential knowledge; challenging notions of color-evasiveness and meritocracy in the internationalization of higher education; and committing to global justice. While IntlCrit tenets are focused on addressing the contexts of international students, the framework provides critical perspectives that can be useful in understanding the experiences of different international student groups by nationality or region. Indeed, it can contribute to more extensive discussions regarding how racism functions globally and in the United States. Lastly, it is important to note that the IntlCrit tenets are not definitive or permanent but are a meaningful initiative that challenges inequities and inequalities toward international students' racial experience. I hope the IntlCrit perspectives contribute to including race and racism in international education scholarship and enhancing the policies and practices in diversity, equity, and inclusion to embrace the global, multicultural, and multi-ethnic/racial contexts.
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HyeJin Tina Yeo, Malaika McKee and William Trent
In this chapter, EYES theory proposes that international students view themselves and appraise their social standing of their own race based in relationship to extant social…
Abstract
In this chapter, EYES theory proposes that international students view themselves and appraise their social standing of their own race based in relationship to extant social perceptions of racial stereotypes in the United States. These stereotypes are determined by geography which exude from the legacy of enslavement in the United States. EYES theory proposes that international students view racial differences through these dynamics by assessing their own identity in regards to race, colorsim and group identification. Specifically, international students use racial groups to classify, rank, and understand racial differences that are informed by these social geographies that impart a white/black racial discourse by which international students navigate their social status. EYES theory challenges the intellectual perception of heterogeneity among international students and in regards to race posits that international students experience mico and macrolevel contexts regarding race due to the socio-historical legacy of racism in the United States. The authors anticipate that EYES theory may have implications for study in other geographical contexts where a black white dichotomy serves as the parameter for understanding racial relationships and hegemony.
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THE Classification of Technology has long been a fruitful source of controversy and discussion, and the problems presented by such discussions are becoming more prominent every…
Abstract
THE Classification of Technology has long been a fruitful source of controversy and discussion, and the problems presented by such discussions are becoming more prominent every day and are among the most interesting to the librarian with a speculative turn of mind. Dr. Richardson in his synthesis of classification arrives at the conclusion that the order of knowledge is the order of things, and that the order of classification is the order of things. Therefore the correct order or arrangement of Technology should follow the same order as that placed before us by Dr. Richardson. To make provision for the better and more systematic classification of Technology for the student and craftsman is the office and responsibility of the librarian.