1,964 research outputs found
An interactive, generative Punch and Judy show using institutions, ASP and emotional agents
Using Punch and Judy as a story domain, we describe an interactive puppet show, where the flow and content of the story can be influenced by the actions of the audience. As the puppet show is acted out, the audience reacts to events by cheering or booing the characters. This affects the agents’ emotional state, potentially causing them to change their actions, altering the course of the narrative. An institutional normative model is used to constrain the narrative so that it remains consistent with the Punch and Judy canon. Through this vignette of a socio-technical system (STS), comprising human and software actors, an institutional model – derived from narrative theory – and (simplistic) technological interaction artifacts, we begin to be able to explore some of the issues that can arise in STS through the prism of the World-Institution-Technology (WIT) model
Epitaxial Growth of LaSrFeO thin films by laser ablation
We report on the synthesis of high quality LaSrFeO (LSFO)
thin films using the pulsed laser deposition technique on both SrTiO (STO)
and LaAlO (LAO) substrates (100)-oriented. From X-Ray diffraction (XRD)
studies, we find that the films have an out-of-plane lattice parameter around
0.3865nm, almost independent of the substrate (i.e. the nature of the strains).
The transport properties reveal that, while LSFO films deposited on STO exhibit
an anomaly in the resistivity vs temperature at 180K (corresponding to the
charge-ordered transition and associated with a transition from a paramagnetic
to an antiferromagnetic state), the films grown on LAO display a very small
magnetoresistance behavior and present an hysteresis around 270K under the
application of a 4T magnetic field. The changes in transport properties between
both substrates are discussed and compared with the corresponding single
crystals.Comment: 9 pages, 4 figure
Irreducible Hamiltonian approach to the Freedman-Townsend model
The irreducible BRST symmetry for the Freedman-Townsend model is derived. The
comparison with the standard reducible approach is also addressed.Comment: 18 pages, LaTeX 2.0
Sparsity driven ultrasound imaging
An image formation framework for ultrasound imaging from synthetic transducer arrays based on sparsity-driven regularization functionals using single-frequency Fourier domain data is proposed. The framework involves the use of a physics-based forward model of the ultrasound observation process, the formulation of image formation as the solution of an associated optimization problem, and the solution of that problem through efficient numerical algorithms. The sparsity-driven, model-based approach estimates a complex-valued reflectivity field and preserves physical features in the scene while suppressing spurious artifacts. It also provides robust reconstructions in the case of sparse and reduced observation apertures. The effectiveness of the proposed imaging strategy is demonstrated using experimental data
Multi-Resolution Analysis and Fractional Quantum Hall Effect: an Equivalence Result
In this paper we prove that any multi-resolution analysis of \Lc^2(\R)
produces, for some values of the filling factor, a single-electron wave
function of the lowest Landau level (LLL) which, together with its (magnetic)
translated, gives rise to an orthonormal set in the LLL. We also give the
inverse construction. Moreover, we extend this procedure to the higher Landau
levels and we discuss the analogies and the differences between this procedure
and the one previously proposed by J.-P. Antoine and the author.Comment: Submitted to Journal Mathematical Physisc
Atmospheric Variability Of Methyl Chloride During the Last 300 Years From an Antarctic Ice Core and Firn Air
Measurements of methyl chloride (CH3Cl) in Antarctic polar ice and firn air are used to describe the variability of atmospheric CH3Cl during the past 300 years. Firn air results from South Pole and Siple Dome suggest that the atmospheric abundance of CH3Cl increased by about 10% in the 50 years prior to 1990. Ice core measurements from Siple Dome provide evidence for a cyclic natural variability on the order of 10%, with a period of about 110 years in phase with the 20th century rise inferred from firn air. Thus, the CH3Cl increase measured in firn air may largely be a result of natural processes, which may continue to affect the atmospheric CH3Cl burden during the 21st century
Temperature-dependent soft x-ray photoemission and absorption studies of charge disproportionation in LaSrFeO
We have measured the temperature dependence of the photoemission and x-ray
absorption spectra of LaSrFeO (LSFO) epitaxial thin films with
, where charge disproportionation () resulting in long-range spin and charge ordering is known to occur
below K. With decreasing temperature we observed gradual changes
of the spectra with spectral weight transfer over a wide energy range of eV. Above the intensity at the Fermi level () was relatively
high compared to that below but still much lower than that in
conventional metals. We also found a similar temperature dependence for
, and to a lesser extent for . These observations suggest that a
local charge disproportionation occurs not only in the sample below
but also over a wider temperature and composition range in LSFO. This
implies that the tendency toward charge disproportionation may be the origin of
the unusually wide insulating region of the LSFO phase diagram.Comment: 6 pages, 8 figure
Chiral Perturbation Theory for , , and
We use heavy vector meson chiral perturbation theory
to predict differential decay distributions for and in the kinematic region where
(here or ) is much smaller than the
chiral symmetry breaking scale. Using the large number of colors limit we also
predict the rate for in this region (now
). Comparing our prediction with experimental data, we determine
one of the coupling constants in the heavy vector meson chiral Lagrangian.Comment: 14 pages, latex 2e. We include the decay of the tau into the omega,
pi minus and the tau neutrino, and extract a value for the coupling constant
g2, using experimental dat
A provenance task abstraction framework
Visual analytics tools integrate provenance recording to externalize analytic processes or user insights. Provenance can be captured on varying levels of detail, and in turn activities can be characterized from different granularities. However, current approaches do not support inferring activities that can only be characterized across multiple levels of provenance. We propose a task abstraction framework that consists of a three stage approach, composed of (1) initializing a provenance task hierarchy, (2) parsing the provenance hierarchy by using an abstraction mapping mechanism, and (3) leveraging the task hierarchy in an analytical tool. Furthermore, we identify implications to accommodate iterative refinement, context, variability, and uncertainty during all stages of the framework. A use case describes exemplifies our abstraction framework, demonstrating how context can influence the provenance hierarchy to support analysis. The paper concludes with an agenda, raising and discussing challenges that need to be considered for successfully implementing such a framework
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