4,331 research outputs found

    Discussion Behaviors and Quiz Performance as a Function of Points for Discussion

    Get PDF
    22 leaves. Advisor: Earle L. CanfieldThe Problem: Social and point-token reinforcement were implemented to increase student question-asking and discussion behaviors. Procedure: Three groups of university college students in small discussion classes were the participants in this study. Baseline data was collected on frequency of student discussion behaviors and on accuracy scores on both an immediate and delayed review quiz. Findings: Results demonstrate that social and point-token reinforcement were highly effective for increasing the rate of discussion behaviors. In addition, increased accuracy scores on the immediate review quiz following discussion of material to be contained in those quizzes were noted. No improvement on the delayed review quiz was observed. Conclusion: Implications are that student interaction with academic material in the form of discussion can increase academic performance. Recommendations: It would appear that efforts should be made to promote as much of this interaction as possible in the classroom

    Heat flow, weighted Bergman spaces, and real analytic Lipschitz approximation

    Get PDF
    We show that, for f any uniformly continuous (UC) complex-valued function on real Euclidean n-space ℝn, the heat flow f˜(t) is Lipschitz for all t > 0 and f˜(t) converges uniformly to f as t → 0. Analogously, let Ω be any irreducible bounded symmetric (Cartan) domain in complex n-space ℂn and consider the Bergman metric β(·,·) on Ω. For f any β-uniformly continuous function Ω, we show that there is a Berezin-Harish-Chandra flow of real analytic functions Bλf which is β-Lipschitz for each λ ≥ p (p, the genus of Ω) and Bλf converges uniformly to f as λ → ∞. For a certain subspace of UC we obtain stronger approximation results and we study the asymptotic behaviour of the Lipschitz constants. © 2015 by De Gruyter

    New direction for gamma-rays

    Full text link
    The origin of energetic gamma-ray bursts is still unknown. But the detection of polarization of gamma-rays provides fresh insight into the mechanism driving these powerful explosions.Comment: Nature "News & Views", RE Coburn & Boggs (astro-ph/0305377

    Completing the puzzle of the 2004-2005 outburst in V0332+53: the brightening phase included

    Full text link
    Analysis of the data obtained with the RXTE observatory during a powerful outburst of the X-ray pulsar V0332+53 in 2004-2005 is presented. Observational data covering the outburst brightening phase are analysed in detail for the first time. A comparison of source parameters and their evolution during the brightening and fading phases shows no evidence for any hysteresis behaviour. It is found that the dependences of the energy of the cyclotron absorption line on the luminosity during the brightening and fading phases are almost identical. The complete data sequence including the outburst brightening and fading phases makes it possible to impose the more stringent constraints on the magnetic field in the source. The pulse profile and pulsed fraction are studied as functions of the luminosity and photon energy.Comment: 9 pages, 10 figures, accepted for publication in MNRA

    Multiple Cyclotron Lines in the Spectrum of 4U 0115+63

    Get PDF
    We report phase resolved spectroscopy of the transient accreting pulsar, 4U0115+63. For the first time, more than two cylotron resonance scattering features are detected in the spectrum of an X-ray pulsar. The shape of the fundamental line appears to be complex, and this is in agreement with predictions of Monte-Carlo models. As in other pulsars, the line energies and optical depths are strong functions of pulse phase. One possible model for this is an offset of the dipole of the neutron star magnetic field.Comment: 5 pages. To appear in "Proceedings of the 5th Compton Symposium

    First results from TOO observations of the Aql X-1 field with INTEGRAL

    Full text link
    We present results of observations of the Aql X-1 field performed in March-April 2003 with the INTEGRAL observatory. This TOO (Target Of Opportunity) INTEGRAL observations was initiated upon receiving an indication from the ASM/RXTE that the source started an outburst. Thirteen X-ray sources were detected by the INTEGRAL imagers, JEM-X and IBIS, during these observations. We present a preliminary spectral and timing analysis for several bright sources in the field, Aql X-1, X1901+03, 4U1907+097, XTE J1908+094 and X1908+075. We also detected two X-ray bursts from Aql X-1 near the end of the general outburst episode.Comment: 5 pages, 7 figures, accepted for publication in the A&

    Longitudinal study of local authority child and family social workers (wave 1) Findings from a 5 year study of local authority child and family social workers in England.

    Get PDF
    The longitudinal study investigates recruitment, retention and career progression in local authority child and family social work over 5 years. This is the first of 5 reports. It provides workforce information for employers and policy makers. Topics covered in this report include: •entry routes into local authority child and family social work •current employment and career history •workplace wellbeing •management, supervision and working environment •job satisfaction •career progression and future career plan

    Toeplitz quantization on Fock space

    Get PDF
    For Toeplitz operators Tf(t)T_f^{(t)} acting on the weighted Fock space Ht2H_t^2, we consider the semi-commutator Tf(t)Tg(t)Tfg(t)T_f^{(t)}T_g^{(t)} - T_{fg}^{(t)}, where t>0t > 0 is a certain weight parameter that may be interpreted as Planck's constant \hbar in Rieffel's deformation quantization. In particular, we are interested in the semi-classical limit \begin{equation}\tag{*} \lim\limits_{t \to 0} \|T_f^{(t)}T_g^{(t)} - T_{fg}^{(t)}\|_t. \end{equation} It is well-known that Tf(t)Tg(t)Tfg(t)t\|T_f^{(t)}T_g^{(t)} - T_{fg}^{(t)}\|_t tends to 00 under certain smoothness assumptions imposed on ff and gg. This result was recently extended to f,g \in \textup{BUC}(\C^n) by Bauer and Coburn. We now further generalize ()(*) to (not necessarily bounded) uniformly continuous functions and symbols in the algebra VMOL\textup{VMO}\cap L^{\infty} of bounded functions having vanishing mean oscillation on Cn\mathbb{C}^n. Our approach is based on the algebraic identity Tf(t)Tg(t)Tfg(t)=(Hfˉ(t))Hg(t)T_f^{(t)}T_g^{(t)} - T_{fg}^{(t)} = -(H_{\bar{f}}^{(t)})^*H_g^{(t)}, where Hg(t)H_g^{(t)} denotes the Hankel operator corresponding to the symbol gg, and norm estimates in terms of the (weighted) heat transform. As a consequence, only ff (or likewise only gg) has to be contained in one of the above classes for ()(*) to vanish. For gg we only have to impose lim supt0Hg(t)t<\limsup_{t \to 0} \|H_g^{(t)}\|_t < \infty, e.g.~g \in L^{\infty}(\C^n). We prove that the set of all symbols fL(Cn)f\in L^{\infty} (\mathbb{C}^n) with the property that limt0Tf(t)Tg(t)Tfg(t)t=limt0Tg(t)Tf(t)Tgf(t)t=0\lim_{t \rightarrow 0}\|T^{(t)}_fT^{(t)}_g-T^{(t)}_{fg}\|_t= \lim_{t \rightarrow 0} \| T_g^{(t)}T_f^{(t)}-T_{gf}^{(t)}\|_t=0 for all gL(Cn)g\in L^{\infty}(\mathbb{C}^n) coincides with VMOL\textup{VMO}\cap L^{\infty}. Additionally, we show that limt0Tf(t)t=f\lim\limits_{t \to 0} \|T_f^{(t)}\|_t = \|f\|_{\infty} holds for all f \in L^{\infty}(\C^n). Finally, we present new examples, including bounded smooth functions, where ()(*) does not vanish

    Local Index Formula on the Equatorial Podles Sphere

    Full text link
    We discuss spectral properties of the equatorial Podles sphere. As a preparation we also study the `degenerate' (i.e. q=0q=0) case (related to the quantum disk). We consider two different spectral triples: one related to the Fock representation of the Toeplitz algebra and the isopectral one. After the identification of the smooth pre-CC^*-algebra we compute the dimension spectrum and residues. We check the nontriviality of the (noncommutative) Chern character of the associated Fredholm modules by computing the pairing with the fundamental projector of the CC^*-algebra (the nontrivial generator of the K0K_0-group) as well as the pairing with the qq-analogue of the Bott projector. Finally, we show that the local index formula is trivially satisfied.Comment: 18 pages, no figures; minor correction
    corecore