5,820 research outputs found
On and Off-diagonal Sturmian operator: dynamic and spectral dimension
We study two versions of quasicrystal model, both subcases of Jacobi
matrices. For Off-diagonal model, we show an upper bound of dynamical exponent
and the norm of the transfer matrix. We apply this result to the Off-diagonal
Fibonacci Hamiltonian and obtain a sub-ballistic bound for coupling large
enough. In diagonal case, we improve previous lower bounds on the fractal
box-counting dimension of the spectrum.Comment: arXiv admin note: text overlap with arXiv:math-ph/0502044 and
arXiv:0807.3024 by other author
Generalized Solutions for Quantum Mechanical Oscillator on K\"{a}hler Conifold
We study the possible generalized boundary conditions and the corresponding
solutions for the quantum mechanical oscillator model on K\"{a}hler conifold.
We perform it by self-adjoint extension of the the initial domain of the
effective radial Hamiltonian. Remarkable effect of this generalized boundary
condition is that at certain boundary condition the orbital angular momentum
degeneracy is restored! We also recover the known spectrum in our formulation,
which of course correspond to some other boundary condition.Comment: 7 pages, latex, no figur
The Human Capital âImpactâ on E-Business: The Case of Encyclopedia Britannica
[Excerpt] The term âNew Economyâ has been coined to describe the remarkable economic performance of the 1990s. Stiroh, (1999) an economist at the Federal Reserve Bank of New York observes that its defining characteristic is a âfocus on increasing globalization and expanding information technologyâ (pg. 87). Research suggests that revenues from electronic based business to business trade will double over the next five years from 1.3 trillion in 2003. Revenues from business to consumer trade are predicted to rise from 108 billion over the same time period (Forrester Research, 1998). However, there is increasing attention to the challenges facing business in the new economy, and an increasing chorus of analysts suggesting how tenuous many of these business models really are. A recent Barronâs article showed that many dot-com companies have only days of remaining cash (Willoughby, March 20, 1999). Such a key emerging phenomenon has not escaped the attention of writers, though the existing body of writing has some important gaps. We would classify existing e-business literature into two groups. First, there is a growing body of literature that discusses the how the Internet is transforming business models and organizational strategies. A second, much smaller body of work has focused on e-HR, or more specifically, the implications of the Internet on various HR practices
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Understanding voice, distribution and listening in Digital Storytelling
This article interrogates the commissioning, production and distribution of Digital Storytelling made through collaborations between academics, practitioners and community groups. In this context, Digital Storytelling is defined as a workshop-based process where participants gain the skills and knowledge needed to tell a personal story using their own words and imagery. It starts with a recognition that the development of new forms of media activity enabled by digitalization have led directly to new modes of community-based media which, in turn, have created spaces for practitioners that emphasize the importance of the voice of the participant. Couldryâs (2010) three concepts of voice are used here to interrogate Digital Storytelling, namely opportunities for new voices to speak and be heard, an increased mutual awareness flowing from a greater influence over distribution and exhibition and the potential for new intensities of listening as a means to explore the notion that digitalization increased the range and number of voices across the media. The article argues that the relatively modest ambitions of many Digital Storytelling projects mean that complex issues are either resolved or sidestepped on a pragmatic, case-by-case basis and, because of this, the work is undertheorized and often poorly understood. Processes of institutional mediation within Digital Storytelling bring into question the reliability of Digital Storytelling as a data source and too often condemn Digital Storytelling to modest outcomes
Understanding voice, distribution and listening in Digital Storytelling
This article interrogates the commissioning, production and distribution of Digital Storytelling made through collaborations between academics, practitioners and community groups. In this context, Digital Storytelling is defined as a workshop-based process where participants gain the skills and knowledge needed to tell a personal story using their own words and imagery. It starts with a recognition that the development of new forms of media activity enabled by digitalization have led directly to new modes of community-based media which, in turn, have created spaces for practitioners that emphasize the importance of the voice of the participant.
Couldryâs (2010) three concepts of voice are used here to interrogate Digital Storytelling, namely opportunities for new voices to speak and be heard, an increased mutual awareness flowing from a greater influence over distribution and exhibition and the potential for new intensities of listening as a means to explore the notion that digitalization increased the range and number of voices across the media.
The article argues that the relatively modest ambitions of many Digital Storytelling projects mean that complex issues are either resolved or sidestepped on a pragmatic, case-by-case basis and, because of this, the work is undertheorized and often poorly understood. Processes of institutional mediation within Digital Storytelling bring into question the reliability of Digital Storytelling as a data source and too often condemn Digital Storytelling to modest outcomes
Analysis of unbounded operators and random motion
We study infinite weighted graphs with view to \textquotedblleft limits at
infinity,\textquotedblright or boundaries at infinity. Examples of such
weighted graphs arise in infinite (in practice, that means \textquotedblleft
very\textquotedblright large) networks of resistors, or in statistical
mechanics models for classical or quantum systems. But more generally our
analysis includes reproducing kernel Hilbert spaces and associated operators on
them. If is some infinite set of vertices or nodes, in applications the
essential ingredient going into the definition is a reproducing kernel Hilbert
space; it measures the differences of functions on evaluated on pairs of
points in . And the Hilbert norm-squared in will represent
a suitable measure of energy. Associated unbounded operators will define a
notion or dissipation, it can be a graph Laplacian, or a more abstract
unbounded Hermitian operator defined from the reproducing kernel Hilbert space
under study. We prove that there are two closed subspaces in reproducing kernel
Hilbert space which measure quantitative notions of limits at
infinity in , one generalizes finite-energy harmonic functions in
, and the other a deficiency index of a natural operator in
associated directly with the diffusion. We establish these
results in the abstract, and we offer examples and applications. Our results
are related to, but different from, potential theoretic notions of
\textquotedblleft boundaries\textquotedblright in more standard random walk
models. Comparisons are made.Comment: 38 pages, 4 tables, 3 figure
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Teaching schools evaluation. Research Brief
This Research Brief reports the findings from a two-year study (2013-15) in to the work of teaching schools and their alliances commissioned by the National College for Teaching and Leadership (NCTL). The broad aim of the study was to investigate the effectiveness and impact of teaching schools on improvement, and identify the quality and scope of external support that are required to enhance these . This was achieved through combining qualitative and quantitative data collection and analysis derived from three research activities: case studies of 26 teaching schools alliances (TSAs), a national survey of the first three cohorts of 345 TSAs, and secondary research and analysis of national performance and inspection results
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