13,227 research outputs found

    Use of the Pyramid Model for Supporting Preschool Refugees

    Get PDF
    Response to Intervention (RtI) is being applied to early childhood settings for the support of positive behavior and social development through the Pyramid Model (Fox, Carta, Strain, Dunlap & Hemmeter, 2010). This qualitative study assessed the use of the Pyramid Model for preschool aged refugee children living in a refugee resettlement community. Many young refugee children have experienced trauma (George, 2010) and some experience behavior and social challenges (Almqvist & Brandell-Forsberg, 1997). Twenty-five preschool service providers were interviewed about their use of the Pyramid Model for the support of preschool refugee students. Themes to be shared include how ECEs are implementing the practices outlined in the Pyramid Model along with strategies for adapting recommended practices to meet the needs of refugee families

    Hierarchical approach to 'atomistic' 3-D MOSFET simulation

    Get PDF
    We present a hierarchical approach to the 'atomistic' simulation of aggressively scaled sub-0.1-μm MOSFETs. These devices are so small that their characteristics depend on the precise location of dopant atoms within them, not just on their average density. A full-scale three-dimensional drift-diffusion atomistic simulation approach is first described and used to verify more economical, but restricted, options. To reduce processor time and memory requirements at high drain voltage, we have developed a self-consistent option based on a solution of the current continuity equation restricted to a thin slab of the channel. This is coupled to the solution of the Poisson equation in the whole simulation domain in the Gummel iteration cycles. The accuracy of this approach is investigated in comparison to the full self-consistent solution. At low drain voltage, a single solution of the nonlinear Poisson equation is sufficient to extract the current with satisfactory accuracy. In this case, the current is calculated by solving the current continuity equation in a drift approximation only, also in a thin slab containing the MOSFET channel. The regions of applicability for the different components of this hierarchical approach are illustrated in example simulations covering the random dopant-induced threshold voltage fluctuations, threshold voltage lowering, threshold voltage asymmetry, and drain current fluctuations

    Future supernovae data and quintessence models

    Full text link
    The possibility to unambiguously determine the equation-of-state of the cosmic dark energy with existing and future supernovae data is investigated. We consider four evolution laws for this equation-of-state corresponding to four quintessential models, i.e. i) a cosmological constant, ii) a general barotropic fluid, iii) a perfect fluid with a linear equation-of-state and iv) a more physical model based on a pseudo-Nambu-Goldstone boson field. We explicitly show the degeneracies present not only within each model but also between the different models : they are caused by the multi-integral relation between the equation-of-state of dark energy and the luminosity distance. Present supernova observations are analysed using a standard χ2\chi^2 method and the minimal χ2\chi^2 values obtained for each model are compared. We confirm the difficulty to discriminate between these models using present SNeIa data only. By means of simulations, we then show that future SNAP observations will not remove all the degeneracies. For example, wrong estimations of Ωm\Omega_m with a good value of χmin2\chi^2_{min} could be found if the right cosmological model is not used to fit the data. We finally give some probabilities to obtain unambiguous results, free from degeneracies. In particular, the probability to confuse a cosmological constant with a true barotropic fluid with an equation-of-state different from -1 is shown to be 95% at a 2σ2 \sigma level.Comment: 12 pages. This improved version has been accepted for publication in M.N.R.A.

    Hot Spots on the Fermi Surface of Bi2212: Stripes versus Superstructure

    Full text link
    In a recent paper Saini et al. have reported evidence for a pseudogap around (pi,0) at room temperature in the optimally doped superconductor Bi2212. This result is in contradiction with previous ARPES measurements. Furthermore they observed at certain points on the Fermi surface hot spots of high spectral intensity which they relate to the existence of stripes in the CuO planes. They also claim to have identified a new electronic band along Gamma-M1 whose one dimensional character provides further evidence for stripes. We demonstrate in this Comment that all the measured features can be simply understood by correctly considering the superstructure (umklapp) and shadow bands which occur in Bi2212.Comment: 1 page, revtex, 1 encapsulated postscript figure (color

    Statefinder -- a new geometrical diagnostic of dark energy

    Get PDF
    We introduce a new cosmological diagnostic pair {r,s}\lbrace r,s\rbrace called Statefinder. The Statefinder is dimensionless and, like the Hubble and deceleration parameters H(z)H(z) and q(z)q(z), is constructed from the scale factor of the Universe and its derivatives only. The parameter r(z)r(z) forms the next step in the hierarchy of geometrical cosmological parameters used to study the Universe after HH and qq, while the parameter s(z)s(z) is a linear combination of qq and rr chosen in such a way that it does not depend upon the dark energy density ΩX(z)\Omega_X(z). The Statefinder pair {r,s}\lbrace r,s\rbrace is algebraically related to the the dark energy pressure-to-energy ratio w=p/ϵw=p/\epsilon and its time derivative, and sheds light on the nature of dark energy/quintessence. Its properties allow to usefully differentiate between different forms of dark energy with constant and variable ww, including a cosmological constant (w=1w = -1). The Statefinder pair can be determined to very good accuracy from a SNAP type experiment.Comment: 7 pages, 3 figures. Final version to be published in JETP Lett., presentation shortened, references added and updated, consideration of brane cosmological models included, conclusions unchange

    Challenges to transferring and sharing of tacit knowledge within a construction supply chain

    Get PDF
    Purpose – This paper investigates the potential challenges that hinder the effective transfer and sharing of Tacit Knowledge (Knowledge Communication) within a construction supply chain (CSC). Design/Methodology/Approach – This study identifies six challenges (through literature review) with fifteen positive correlations between them. Quantitative methodology is employed to validate those challenges and correlations between challenges. Firstly, data is collected through semi-structured e-survey questionnaire. Afterwards, a Frequency and Kruskal-Wallis H test is run for initial validation of identified challenges. A correlation analysis is used to highlight the taxonomic relations between those challenges. Finally, the study establishes the rank order of the first and following challenges. Findings – This study highlights that traditional ways of working with construction organisations are the predominant challenge that hinders effective transferring and sharing of Tacit Knowledge. The cause of challenges is the fragmented nature of CSC. Also, it brings out the correlation between those challenges. The study draws the conclusion and recommendation to implement Knowledge Communication (KC) within a CSC. Originality/Value – The study highlights the challenges that hinder KC in a construction process of a CSC. It establishes that the fragmented nature of the construction sector is not the first challenge that hinders implementation of transferring and sharing of Tacit Knowledge but somewhat traditional organisation structures and working processes. This is the first paper that investigates and tests the challenges in four dimensions and establishes the rank order of challenges with crucial distinction in a KC approach within a CSC. Conclusion – This study identifies the rank order of challenges. It also discusses the implementation of KC within a CSC. It reflects the current understanding of KC in the construction sector and pinpoints the contribution of this study in academia and practice. Keywords - Construction Supply Chains, Knowledge Management, Tacit Knowledge, Transferring and Sharing Tacit Knowledge, Knowledge Communication in Construction Processes, Knowledge Communicatio
    corecore