排序方式： 共有46条查询结果，搜索用时 15 毫秒
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Bergey Bradley W. Ketelhut Diane Jass Liang Senfeng Natarajan Uma Karakus Melissa 《Journal of Science Education and Technology》2015,24(5):696-708
Journal of Science Education and Technology - The primary aim of the study was to examine whether performance on a science assessment in an immersive virtual environment was associated with changes... 相似文献
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Space and time are concepts that seem to be embedded in our very consciousness. As we grow up, our ‘intuitive understanding’
of these concepts seems to grow as well. And yet the fact is that our understanding of space-time in the deepest scientific
sense is far from complete, although we have covered a considerable distance along the route. There may still be many surprises
awaiting us on the road ahead. 相似文献
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Theoretical analysis of the ‘simple’ pendulum beyond the small-angle approximation teaches us about anharmonic oscillators
and approximate (perturbative) solutions. Experiments with a simple-to-set-up pendulum teach us about errors in measurements,
and curve fitting of theoretical expressions to experimental data. The pendulum also exhibits frictional damping, a feature
of most real oscillators. 相似文献
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Vasant Natarajan 《Resonance》2010,15(8):723-732
The Physics Nobel Prize, 2009 has been awarded jointly: one half to Charles K Kao “for groundbreaking achievements concerning
the transmission of light in fibers for optical communication”, and the other half to Willard S Boyle and George E Smith “for
the invention of an imaging semiconductor circuit — the CCD sensor”. In this article, we explain the basic ideas behind these
inventions, and why the choice is appropriate in interpreting Alfred Nobel’s will in who should get these prizes. 相似文献
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Katie J. Thralls Suneeta Godbole Todd M. Manini Eileen Johnson Loki Natarajan Jacqueline Kerr 《Journal of sports sciences》2013,31(20):2309-2317
ABSTRACTThis study compared five different methods for analyzing accelerometer-measured physical activity (PA) in older adults and assessed the relationship between changes in PA and changes in physical function and depressive symptoms for each method. Older adult females (N = 144, Mage = 83.3 ± 6.4yrs) wore hip accelerometers for six days and completed measures of physical function and depressive symptoms at baseline and six months. Accelerometry data were processed by five methods to estimate PA: 1041 vertical axis cut-point, 15-second vector magnitude (VM) cut-point, 1-second VM algorithm (Activity Index (AI)), machine learned walking algorithm, and individualized cut-point derived from a 400-meter walk. Generalized estimating equations compared PA minutes across methods and showed significant differences between some methods but not others; methods estimated 6-month changes in PA ranging from 4 minutes to over 20 minutes. Linear mixed models for each method tested associations between changes in PA and health. All methods, except the individualized cut-point, had a significant relationship between change in PA and improved physical function and depressive symptoms. This study is among the first to compare accelerometry processing methods and their relationship to health. It is important to recognize the differences in PA estimates and relationship to health outcomes based on data processing method.Abbreviation: Machine Learning (ML); Short Physical Performance Battery (SPPB); Center of Epidemiologic Studies Depression Scale (CES-D); Physical Activity (PA); Activity Index (AI); Activities of Daily Living (ADL) 相似文献
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Vasant Natarajan 《Resonance》2012,17(11):1048-1053
We discuss the purported link between cell phone radiation and cancer. We show that it is inconsistent with the photoelectric effct, and that epidemiological studies of any link have no scientific basis. 相似文献
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