14,435 research outputs found
Roll function in a flight simulator
Method introduces roll into the flying-spot scanner by modifying the scanning waveforms
Moduli spaces of noncommutative instantons: gauging away noncommutative parameters
Using the theory of noncommutative geometry in a braided monoidal category,
we improve upon a previous construction of noncommutative families of
instantons of arbitrary charge on the deformed sphere S^4_\theta. We formulate
a notion of noncommutative parameter spaces for families of instantons and we
explore what it means for such families to be gauge equivalent, as well as
showing how to remove gauge parameters using a noncommutative quotient
construction. Although the parameter spaces are a priori noncommutative, we
show that one may always recover a classical parameter space by making an
appropriate choice of gauge transformation.Comment: v2: 44 pages; minor changes. To appear in Quart. J. Mat
A study of the means of increasing the dynamic range of visual simulation by means of a flying-spot scanner Final report
Increasing dynamic range of visual simulation for pilots using flying spot scanne
Financial Engineering and Rationality: Experimental Evidence Based on the Monty Hall Problem
Financial engineering often involves redefining existing financial assets to create new financial products. This paper investigates whether financial engineering can alter the environment so that irrational agents can quickly learn to be rational. The specific environment we investigate is based on the Monty Hall problem, a well-studied choice anomaly. Our results show that, by the end of the experiment, the majority of subjects understand the Monty Hall anomaly. Average valuation of the experimental asset is very close to the expected value based on the true probabilities.experiment, behavioral finance
The Gysin Sequence for Quantum Lens Spaces
We define quantum lens spaces as `direct sums of line bundles' and exhibit
them as `total spaces' of certain principal bundles over quantum projective
spaces. For each of these quantum lens spaces we construct an analogue of the
classical Gysin sequence in K-theory. We use the sequence to compute the
K-theory of the quantum lens spaces, in particular to give explicit geometric
representatives of their K-theory classes. These representatives are
interpreted as `line bundles' over quantum lens spaces and generically define
`torsion classes'. We work out explicit examples of these classes.Comment: 27 pages. v2: No changes in the scientific content and results.
Section 5 completely re-written and a final section added; suppressed two
appendices; added references; minor changes throughout the paper. To appear
in the JNc
Regional Strategies of Multinational Pharmaceutical Firms
This paper examines the R&D and strategies of the world’s largest firms in the pharmaceuticals sector and finds a high degree of intra-regional sales. R&D and sales are more concentrated within North America and Europe than in Asia. In addition, the relative size of the U.S. market, compared to other parts of the triad, creates imbalances with respect to R&D, sales and international strategy.
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Polymer Matrix Nanocomposites by Inkjet Printing
This paper describes work on a continuing project to form functional composites that contain
ceramic nanoparticles using a Solid Freeform Fabrication (SFF) inkjet printing method. The process
involves inkjet deposition of monomer/particle suspensions in layers followed by curing each layer in
sequence using UV radiation. The reactive monomer is hexanediol-diacrylate (HDODA); the polymer
forming reaction proceeds by a free radical mechanism. The liquid monomer containing nanoparticles
is essentially a printing ink formulation. Successfully suspending the particles in the monomer is
critical. We have developed a surface treatment method for forming stable suspensions of the
nanoparticles so that they remain discrete throughout the processing sequence.
The SFF process involves careful control of the polymer cure so that the interface between layers
is seamless and residual stresses in the composites are eliminated. An immediate use for such
composites is in optical applications as gradient refractive index lenses (GRIN). GRIN lenses have
planar surfaces, eliminating the need for costly grinding and polishing. The planar surfaces also
eliminate optical aberrations that result at the edges of spherical lenses and diminish the accuracy of
focus.
If the appropriate nanoparticles are fully dispersed they will modify the polymer's refractive index
without interfering with light transmission. The effect is additive with volume concentration. Using
'inks' of different compositions in a multiple nozzle inkjet printer allows the formation of composites
with precise composition gradients. Since an object is built one planar layer at a time, changes can be
made readily both within each layer and from layer to layer. Inkjet printing with picoliter resolution is
ideal for this task.
Working with SiC nanoparticles in HDODA as a model system for demonstrating the inkjet
deposition process, nanocomposite films with a linear concentration gradient varying from 0 to 4.5%
(wt) were fabricated on Silicon wafers. These composites are 30 layer films, which total 140µm in
thickness. Each layer in the composite is about 5 µm in thickness. Analytical methods for
characterizing the dispersion of the nanoparticles in the composite and some of the salient optical
properties of the composites also were established. The status of the program is reviewed in this
paper.Mechanical Engineerin
Gauge Theory for Spectral Triples and the Unbounded Kasparov Product
We explore factorizations of noncommutative Riemannian spin geometries over
commutative base manifolds in unbounded KK-theory. After setting up the general
formalism of unbounded KK-theory and improving upon the construction of
internal products, we arrive at a natural bundle-theoretic formulation of gauge
theories arising from spectral triples. We find that the unitary group of a
given noncommutative spectral triple arises as the group of endomorphisms of a
certain Hilbert bundle; the inner fluctuations split in terms of connections
on, and endomorphisms of, this Hilbert bundle. Moreover, we introduce an
extended gauge group of unitary endomorphisms and a corresponding notion of
gauge fields. We work out several examples in full detail, to wit Yang--Mills
theory, the noncommutative torus and the -deformed Hopf fibration over
the two-sphere.Comment: 50 pages. Accepted version. Section 2 has been rewritten. Results in
sections 3-6 are unchange
Moduli Spaces of Instantons on Toric Noncommutative Manifolds
We study analytic aspects of U(n) gauge theory over a toric noncommutative
manifold . We analyse moduli spaces of solutions to the self-dual
Yang-Mills equations on U(2) vector bundles over four-manifolds ,
showing that each such moduli space is either empty or a smooth Hausdorff
manifold whose dimension we explicitly compute. In the special case of the
four-sphere we find that the moduli space of U(2) instantons with
fixed second Chern number is a smooth manifold of dimension .Comment: 44 pages, no figure
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