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81.
In most real-life bilateral teleoperators the available physical parameters are uncertain and the communications exhibit variable time-delays. In order to confront these situations and only assuming that a bound of the time-delays is known, the present work reports an adaptive controller which ensures asymptotic convergence of both position errors and velocities to zero, provided that a sufficient condition on the control gains is met. Compared to previous related works that only treated constant time-delays, the stability analysis does not rely on the cascade interconnection structure of the local and remote nonlinear dynamics and the linear interconnection map. Instead, the paper employs a different Lyapunov candidate function that incorporates a strictly positive term, the local and remote position error. Some simulations, in free space and interacting with a rigid wall, and experiments, using two nonlinear manipulators, illustrate the performance of the proposed control scheme in the presence of uncertain parameters and variable time-delays. 相似文献
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In this report, we demonstrate a simple and low cost method that can be reproducibly used for fabrication of microfluidic devices in nitrocellulose. The fluidic patterns are created via a laser-based direct-write technique that induces polymerisation of a photo-polymer previously impregnated in the nitrocellulose. The resulting structures form hydrophobic barriers that extend through the thickness of the nitrocellulose and define an interconnected hydrophilic fluidic-flow pattern. Our experimental results show that using this method it is possible to achieve microfluidic channels with lateral dimensions of ∼100 μm using hydrophobic barriers that form the channel walls with dimensions of ∼60 μm; both of these values are considerably smaller than those that can be achieved with other current techniques used in the fabrication of nitrocellulose-based fluidic devices. A simple grid patterned nitrocellulose device was then used for the detection of C-reactive protein via a sandwich enzyme-linked immunosorbent assay, which served as a useful proof-of-principle experiment. 相似文献
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Higher Education - In recent years, government policies that target the rapid internationalization of Japanese higher education have provided new career opportunities especially for scholars with... 相似文献
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Dockrell J. E. Papadopoulos T. C. Mifsud C. L. Bourke L. Vilageliu O. Bešić E. Seifert S. Gasteiger-Klicpera B. Ralli A. Dimakos I. Karpava S. Martins M. Sousa O. Castro S. Søndergaard Knudsen H. B. Donau P. Haznedar B. Mikulajová M. Gerdzhikova N. 《European Journal of Psychology of Education - EJPE》2022,37(2):293-320
School classrooms within the EU are multilingual learning environments. The diversity of pupils in classrooms raises significant challenges for teachers, but to date, there are no data from large-scale surveys that compare views within and across European countries. A bespoke questionnaire was designed to examine views of current classroom learning environments with respect to the multilingualism. The questionnaire was piloted and subsequently completed by 2792 teachers across different European countries. Eleven countries provided sufficient data for analyses. Results from structural equation modelling showed that teachers’ attitudes could be reliably measured across Europe with the use of carefully devised questionnaire, whose loading and factor structure remained invariant across countries. Teachers’ views about multilingualism were most challenged by the numbers of children in their classes, not the percentage of multilingual pupils in the class. Countries differed in how they perceived multilingualism, with their differences leading to distinctive country clusters. Gender and education level (elementary vs. secondary) differences were also observed irrespective of country. These findings enhance our understanding of the role that the characteristics of teachers and their classrooms play in a multilingual setting across diverse European settings. The practical relevance of the results and new opportunities for teacher training are discussed.
相似文献86.
George K. Georgiou Timothy C. Papadopoulos Eleni L. Kaizer 《Reading and writing》2014,27(8):1379-1394
The present 10-year longitudinal study examined how rapid automatized naming (RAN) components—articulation time and pause time—relate to reading fluency. Seventy-five Greek-speaking children were followed from Grade 1 to Grade 10 and were assessed five times (in Grades 1, 2, 4, 6, and 10) on RAN (digits and objects) and reading fluency (word reading efficiency, phonemic decoding efficiency, and text reading fluency). The results indicated first that a substantial amount of variance in reading fluency was accounted for by what articulation time and pause time shared. In addition, the unique contribution of pause time to reading fluency decreased across time and the unique contribution of articulation time increased across time. Viewed in conjunction with the developmental changes in the RAN components, our findings suggest that the RAN tasks are processed and executed in different ways across time. 相似文献
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Ioannis Papadopoulos 《Science & Education》2014,23(1):61-77
This paper describes a classroom experiment where students use techniques found in the history of mathematics to learn about an important mathematical idea. More precisely, sixth graders in a primary school follow Archimedes’s method of exhaustion in order to compute the number π. Working in a computer environment, students inscribe and circumscribe regular polygons inside and around a circle in order to find the approximate area of the circle. They then compute the ratio of that approximation to the area of a square with side-length equal to the radius of the circle. This ratio indicates how many times larger the area of the circle is than the area of the square. Mirroring Archimedes’s findings, students discover that as they increase the number of sides in their polygons, the numerical results they obtain convince them that this number is almost equal to 3.14. 相似文献
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This paper uses an autoethnography to recount my experiences with SportHelp, a UK youth sports charity. Using a layered account format, which jumps through time and space, I demonstrate the extent to which neoliberal values have influenced the continuity and change of SportHelp. This paper does not constitute an attack on the charity, its staff, nor the charity sector. The focus is on how the wider neoliberal context shapes how SportHelp operates. The findings are analysed in terms of Foucault’s (2008, The birth of biopolitics. Lectures at the Collége de France, 1978–79. Basingstoke: Palgrave Macmillan) notion of governmentality by examining SportHelp’s monitoring and reporting practices, as well as the managers’ use of New Public Management discourse. The conclusion reflects on the extent to which neoliberal governmentality, though in some instances beneficial for SportHelp, ultimately does more harm than good. This paper, by offering an ‘insider’s view’, adds to the literature calling for a change in how policy makers and funders shape the current hypercompetitive socio-political landscape. Charities should be supported, not discouraged, to develop holistic programmes that move beyond ‘economic rationales’ and are capable of addressing the multifaceted needs of their service users. 相似文献
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Eleni A. Kortianou Ioannis G. Nasis Stavroula T. Spetsioti Andreas M. Daskalakis Ioannis Vogiatzis 《Cardiopulmonary Physical Therapy Journal》2010,21(3):12-19
Physical training is beneficial and should be included in the comprehensive management of all patients with COPD independently of disease severity. Different rehabilitative strategies and training modalities have been proposed to optimize exercise tolerance. Interval exercise training has been used as an effective alternative modality to continuous exercise in patients with moderate and severe COPD.Although in healthy elderly individuals and patients with chronic heart failure there is evidence that this training modality is superior to continuous exercise in terms of physiological training effects, in patients with COPD, there is not such evidence. Nevertheless, in patients with COPD application of interval training has been shown to be equally effective to continuous exercise as it induces equivalent physiological training effects but with less symptoms of dyspnea and leg discomfort during training.The main purpose of this review is to summarize previous studies of the effectiveness of interval training in COPD and also to provide arguments in support of the application of interval training to overcome the respiratory and peripheral muscle limiting factors of exercise capacity. To this end we make recommendations on how best to implement interval training in the COPD population in the rehabilitation setting so as to maximize training effects.Key Words: interval exercise training, chronic obstructive pulmonary disease, exercise tolerance, pulmonary rehabilitation 相似文献
90.
Dockrell J. E. Papadopoulos T. C. Mifsud C. L. Bourke L. Vilageliu O. Bešić E. Seifert S. Gasteiger-Klicpera B. Ralli A. Dimakos I. Karpava S. Martins M. Sousa O. Castro S. Knudsen H. B. Søndergaard Donau P. Haznedar B. Mikulajová M. Gerdzhikova N. 《European Journal of Psychology of Education - EJPE》2022,37(2):321-323
European Journal of Psychology of Education - A Correction to this paper has been published: https://doi.org/10.1007/s10212-021-00539-z 相似文献