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271.
There is now widespread recognition that digital technologies, particularly portable hand held devices capable of Internet connection, present opportunities and challenges to the way in which student learning is organized in schools, colleges and institutions of higher education in the 21st Century. Traxler, Journal of the Research Centre for Educational Technology, 6(1), 3–15 (2010) suggests such devices are pervasive and ubiquitous, conspicuous and unobtrusive, noteworthy and taken-for-granted with everyone typically owning one, using one and often having more than one. As a consequence it has been argued that the availability of such devices, controlled mainly by the student and not the teacher, has the potential to change the traditional dynamics and pedagogical patterns of the learning environment (Burden et al. 2012). Education institutions, however, typically remain organized around spatial and temporal considerations such as buildings, timetables, calendars and internal structures which are designed to classify and manage students. In the case study reported here students and faculty teaching staff from the College of Education in the Kuwait University were surveyed in order to assess their access to such technologies, their capability to use them effectively in support of achieving planned learning outcomes and the implications for change that could emanate from such findings. 相似文献
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273.
In this work, synchronization of chaotic Colpitts circuits, using adaptive controllers to combat circuit parameter mismatches and channel distortions, is studied by numerical simulations. Synchronization errors caused by different main circuit components are compared, and compensation for time-constant and time-varying circuit parameter mismatches is demonstrated. Different kinds of channel distortions, including time-constant and time-varying channel attenuation, Additive White Gaussian Noise (AWGN) are all investigated by numerical simulations and discussed. Simulation results indicated that the synchronization performance of chaotic Colpitts circuits can be greatly improved by applying adaptive controllers when parameter mismatches and channel attenuation are considered as time-constant or time-varying, but have no obvious enhancements regarding the effect on AWGN channel. 相似文献
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276.
Spelling skills have been identified as one of the major barriers to written text production in young English writers. By contrast oral language skills and text generation have been found to be less influential in the texts produced by beginning writers. To date, our understanding of the role of spelling skills in transparent orthographies is limited. The current study addressed this gap by examining the contribution of spelling, oral language and text generation skills in written text production in Italian beginner writers. Eighty-three children aged 7–8 years participated in the study. Spelling, lexical retrieval, receptive grammar, and written sentence generation and reformulation skills were assessed and children were asked to write a text on a set topic. A factor analysis revealed that the children’s written text production was captured by three factors: productivity, complexity and accuracy. In contrast to results from children learning to write in opaque orthographies, such as English, this study showed that receptive grammar and written sentence generation skills accounted for significant variance in measures of productivity, complexity and accuracy in Italian children’s written text production. Spelling skills contributed to text accuracy and quality and explained more variance than receptive grammar in microstructural accuracy. By contrast, oral grammatical skills explained more variance in text quality than spelling. The current study shows the differential impact of language systems, such as Italian, on written text production. Implications for assessment and instruction are outlined. 相似文献
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278.
Analysis of self-reflections of undergraduate education students in a project involving web-supported counterintuitive science demonstrations is reported in this paper. Participating students (N?=?19) taught science with counterintuitive demonstrations in local elementary school classrooms and used web-based resources accessed via wireless USB adapters. Student reflections to seven questions were analyzed qualitatively using four components of reflection (meeting objectives/perception of learning, dynamics of pedagogy, special needs accommodations, improving teaching) deriving 27 initial data categories and 12 emergent themes. Overall the undergraduates reported meeting objectives, engaging students in pedagogically relevant learning tasks including, providing accommodations to students with special needs, and gaining practice and insight to improve their own teaching. Additional research is needed to arrive at generalizable findings concerning teaching with web-supported counterintuitive science demonstrations in elementary classrooms. 相似文献
279.
Based on the momentum conservation approach, a theoretical model was developed to predict the superficial liquid velocity, and a correlation equation was established to calculate the gas holdup of an annular external- loop airlift reactor(AELAR)in the bubble flow and developing slug flow pattern. Experiments were performed by using tap-water and silicone oil with the viscosity of 2.0 mm2/s(2cs-SiO)and 5.0 mm2/s(5cs-SiO)as liquid phases. The effects of liquid viscosity and flow pattern on the AELAR performance were investigated. The predictions of the proposed model were in good agreement with the experimental results of the AELAR. In addition, the comparison of the experimental results shows that the proposed model has good accuracy and could be used to predict the gas holdup and liquid velocity of an AELAR operating in bubble and developing flow pattern. 相似文献
280.
T Padmanabhan 《Resonance》2007,12(2):4-16
The discovery of the cosmic microwave background radiation in 1965 was a defining moment in the history of cosmology — the
science that deals with the universe as a whole, its origin, evolution and future. This discovery was recognized with Nobel
Prizes to Penzias and Wilson in 1978. The Nobel Prize in Physics for 2006 further acknowledged the importance of the study
of this background radiation. The precise measurement of the spectrum of this radiation and its variation across the sky have
helped our understanding of the evolution of structures in the universe. This article explains these discoveries and their
importance.
T Padmanabhan is a professor at IUCAA, Pune. He is interested in all aspects of theoretical physics, and especially in those
in which gravity plays a role. 相似文献