2,107 research outputs found

    The hole in the wall: self organising systems in education

    Get PDF
    Transcript of a keynote speech by Sugata Mitra at “Into something rich and strange” – making sense of the sea-change, the 2010 Association for Learning Technology Conference in Nottingham, England. In the chair, Richard Noss, Co-director of the London Knowledge Lab. This text transcript is at http://repository.alt.ac.uk/855/ [82 kB PDF]. A one hour video of the talk is on the ALT-C 2010 web site at http://www.alt.ac.uk/altc2010/ and on the ALT YouTube channel at http://youtube.com/ClipsFromALT/. Alongside this there will be an experimental version of the video that includes the #altc2010 twitter stream at the time of Sugata’s talk. Made publicly available by ALT in November 2010 under a Creative Commons Attribution-Non-Commercial 2.0 UK: England & Wale

    On topological upper-bounds on the number of small cuspidal eigenvalues

    Full text link
    Let SS be a noncompact, finite area hyperbolic surface of type (g,n)(g, n). Let ΔS\Delta_S denote the Laplace operator on SS. As SS varies over the {\it moduli space} Mg,n{\mathcal{M}_{g, n}} of finite area hyperbolic surfaces of type (g,n)(g, n), we study, adapting methods of Lizhen Ji \cite{Ji} and Scott Wolpert \cite{Wo}, the behavior of {\it small cuspidal eigenpairs} of ΔS\Delta_S. In Theorem 2 we describe limiting behavior of these eigenpairs on surfaces SmMg,n{S_m} \in {\mathcal{M}_{g, n}} when (Sm)({S_m}) converges to a point in Mg,n\overline{\mathcal{M}_{g, n}}. Then we consider the ii-th {\it cuspidal eigenvalue}, λic(S){\lambda^c_i}(S), of SMg,nS \in {\mathcal{M}_{g, n}}. Since {\it non-cuspidal} eigenfunctions ({\it residual eigenfunctions} or {\it generalized eigenfunctions}) may converge to cuspidal eigenfunctions, it is not known if λic(S){\lambda^c_i}(S) is a continuous function. However, applying Theorem 2 we prove that, for all k2g2k \geq 2g-2, the sets Cg,n14(k)={SMg,n:λkc(S)>14}{{\mathcal{C}_{g, n}^{\frac{1}{4}}}}(k)= \{ S \in {\mathcal{M}_{g, n}}: {\lambda_k^c}(S) > \frac{1}{4} \} are open and contain a neighborhood of i=1nM0,3Mg1,2{\cup_{i=1}^n}{\mathcal{M}_{0, 3}} \cup {\mathcal{M}_{g-1, 2}} in Mg,n\overline{\mathcal{M}_{g, n}}. Moreover, using topological properties of nodal sets of {\it small eigenfunctions} from \cite{O}, we show that Cg,n14(2g1){{\mathcal{C}_{g, n}^{\frac{1}{4}}}}(2g-1) contains a neighborhood of M0,n+1Mg,1{\mathcal{M}_{0, n+1}} \cup {\mathcal{M}_{g, 1}} in Mg,n\overline{\mathcal{M}_{g, n}}. These results provide evidence in support of a conjecture of Otal-Rosas \cite{O-R}.Comment: 24 pages, 1 figur

    International Trade and Local Organization of Production - Two Elementary Propositions

    Get PDF
    This paper argues that international trade should affect local organization of production in a systematic way. By using the standard Heckscher-Ohlin-Samuelson model we show that the export sector is more likely to demonstrate fragmentation, entrepreneurship and outsourcing compared to the import-competing sector in a typical labor abundant country. Liberal trade regime will promote entrepreneurship in general. This is the first elementary proposition. Local outsourcing also establishes a clear link between trade and productivity. This is the second elementary proposition.Trade, outsourcing, entrepreneurship, productivity
    corecore