3,105 research outputs found

    The Development of Instruments for Assessment of Instructional Practices in Standards-Based Teaching

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    We provide a description and rationale for the development of two instruments: 1) a classroom observation protocol; and, 2) a teacher interview protocol—designed to document the impact of reform-based professional development with undergraduate mathematics and science faculty, and its impact on the resultant preparation of teachers. Constructed upon review of the research on teaching and standards documents in mathematics and science, these instruments form the basis for data collection in a three-year longitudinal study of teaching practice among early career teachers as well as undergraduate college faculty. In addition, we suggest further applications of the observation protocol beyond the original purpose of our research study

    Adapting structuration theory to understand the role of reflexivity: Problematization, clinical audit and information systems

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    This paper is an exploratory account of the further development and application of a hybrid framework, StructurANTion, that is based on Structuration Theory and Actor Network Theory (ANT). The use of social theories in general and their use in information systems (IS) research in particular is explored leading to the use of the framework to examine the concept of what are termed humanchine networks in the context of clinical audit, within a healthcare Primary Care Trust (PCT). A particular focus is on the manner in which information systems-based reflexivity contributes to both entrenching a networks’ structurated order as well as contributing to its emancipatory change. The case study compares clinic-centric and patientcentric audit and seeks to further extend the understanding of the role of information and information systems within structurated humanchine activity systems. Conclusions indicate that the use of more socially informed IS methods and approaches can incorporate more emancipatory ideals and lead to greater adoption and usage of more relevant and useful clinical information systems and practices

    Measurements of the short-term stability of quartz crystal resonators: A window on future developments in crystal oscillators

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    Recent measurements of the inherent short-term stability of quartz crystal resonators are presented. These measurements show that quartz resonators are much more stable for times less than 1s than the best available commercial quartz oscillators. A simple model appears to explain the noise mechanism in crystal controlled oscillators and points the way to design changes which should permit more than 2 orders of magnitude improvement in their short-term stability. Calculations show that a reference signal at 1 THz, derived from frequency multiplying a 5 MHz source with the above measured crystal stability, should have an instantaneous or fast linewidth of order 1 Hz. These calculations explicitly include the noise contribution of our present multiplier chains and are briefly outlined

    Asymptotic silence-breaking singularities

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    We discuss three complementary aspects of scalar curvature singularities: asymptotic causal properties, asymptotic Ricci and Weyl curvature, and asymptotic spatial properties. We divide scalar curvature singularities into two classes: so-called asymptotically silent singularities and non-generic singularities that break asymptotic silence. The emphasis in this paper is on the latter class which have not been previously discussed. We illustrate the above aspects and concepts by describing the singularities of a number of representative explicit perfect fluid solutions.Comment: 25 pages, 6 figure

    Randomized Smoothing for Stochastic Optimization

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    We analyze convergence rates of stochastic optimization procedures for non-smooth convex optimization problems. By combining randomized smoothing techniques with accelerated gradient methods, we obtain convergence rates of stochastic optimization procedures, both in expectation and with high probability, that have optimal dependence on the variance of the gradient estimates. To the best of our knowledge, these are the first variance-based rates for non-smooth optimization. We give several applications of our results to statistical estimation problems, and provide experimental results that demonstrate the effectiveness of the proposed algorithms. We also describe how a combination of our algorithm with recent work on decentralized optimization yields a distributed stochastic optimization algorithm that is order-optimal.Comment: 39 pages, 3 figure

    Continuous Proctoclysis.

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    Cosmological Phase Transitions and their Properties in the NMSSM

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    We study cosmological phase transitions in the Next-to-Minimal Supersymmetric Standard Model (NMSSM) in light of the Higgs discovery. We use an effective field theory approach to calculate the finite temperature effective potential, focusing on regions with significant tree-level contributions to the Higgs mass, a viable neutralino dark matter candidate, 1-2 TeV stops, and with the remaining particle spectrum compatible with current LHC searches and results. The phase transition structure in viable regions of parameter space exhibits a rich phenomenology, potentially giving rise to one- or two-step first-order phase transitions in the singlet and/or SU(2)SU(2) directions. We compute several parameters pertaining to the bubble wall profile, including the bubble wall width and Δβ\Delta\beta (the variation of the ratio in Higgs vacuum expectation values across the wall). These quantities can vary significantly across small regions of parameter space and can be promising for successful electroweak baryogenesis. We estimate the wall velocity microphysically, taking into account the various sources of friction acting on the expanding bubble wall. Ultra-relativistic solutions to the bubble wall equations of motion typically exist when the electroweak phase transition features substantial supercooling. For somewhat weaker transitions, the bubble wall instead tends to be sub-luminal and, in fact, likely sub-sonic, suggesting that successful electroweak baryogenesis may indeed occur in regions of the NMSSM compatible with the Higgs discovery.Comment: 49 pages + 2 appendices, 6 figures. v2: Minor corrections; matches version published in JHE
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