130,127 research outputs found
Principal Nested Spheres for Time Warped Functional Data Analysis
There are often two important types of variation in functional data: the
horizontal (or phase) variation and the vertical (or amplitude) variation.
These two types of variation have been appropriately separated and modeled
through a domain warping method (or curve registration) based on the Fisher Rao
metric. This paper focuses on the analysis of the horizontal variation,
captured by the domain warping functions. The square-root velocity function
representation transforms the manifold of the warping functions to a Hilbert
sphere. Motivated by recent results on manifold analogs of principal component
analysis, we propose to analyze the horizontal variation via a Principal Nested
Spheres approach. Compared with earlier approaches, such as approximating
tangent plane principal component analysis, this is seen to be the most
efficient and interpretable approach to decompose the horizontal variation in
some examples
Supergravity approach to tachyon condensation on the brane-antibrane system
We study the tachyon condensation on the D-brane--antiD-brane system from the
supergravity point of view. The non-supersymmetric supergravity solutions with
symmetry ISO() SO() are known to be characterized by three
parameters. By interpreting this solution as coincident D-branes and
-branes we give, for the first time, an explicit
representation of the three parameters of supergravity solutions in terms of
and the tachyon vev. We demonstrate that the solution and the
corresponding ADM mass capture all the required properties and give a correct
description of the tachyon condensation advocated by Sen on the
D-brane--antiD-brane system.Comment: 9 page
Phenomenological Analysis of and Elastic Scattering Data in the Impact Parameter Space
We use an almost model-independent analytical parameterization for and
elastic scattering data to analyze the eikonal, profile, and
inelastic overlap functions in the impact parameter space. Error propagation in
the fit parameters allows estimations of uncertainty regions, improving the
geometrical description of the hadron-hadron interaction. Several predictions
are shown and, in particular, the prediction for inelastic overlap
function at TeV shows the saturation of the Froissart-Martin
bound at LHC energies.Comment: 15 pages, 16 figure
CTMC calculations of electron capture and ionization in collisions of multiply charged ions with elliptical Rydberg atoms
We have performed classical trajectory Monte Carlo (CTMC) studies of electron
capture and ionization in multiply charged (Q=8) ion-Rydberg atom collisions at
intermediate impact velocities. Impact parallel to the minor and to the major
axis, respectively, of the initial Kepler electron ellipse has been
investigated. The important role of the initial electron momentum distribution
found for singly charged ion impact is strongly disminished for higher
projectile charge, while the initial spatial distribution remains important for
all values of Q studied.Comment: 3 pages, 5 figure
Process migration in UNIX environments
To support process migration in UNIX environments, the main problem is how to encapsulate the location dependent features of the system in such a way that a host independent virtual environment is maintained by the migration handlers on the behalf of each migrated process. An object-oriented approach is used to describe the interaction between a process and its environment. More specifically, environmental objects were introduced in UNIX systems to carry out the user-environment interaction. The implementation of the migration handlers is based on both the state consistency criterion and the property consistency criterion
Correctness criteria for process migration
Two correctness criteria, the state consistency criterion and the property consistency criterion for process migration are discussed. The state machine approach is used to model the interactions between a user process and its environment. These criteria are defined in terms of the model. The idea of environment view was introduced to distinguish what a user process observes about its environment from what its environment state really is and argue that a consistent view of the environment must be maintained for every migrating process
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