593 research outputs found
A shooting algorithm for problems with singular arcs
In this article we propose a shooting algorithm for a class of optimal
control problems for which all control variables appear linearly. The shooting
system has, in the general case, more equations than unknowns and the
Gauss-Newton method is used to compute a zero of the shooting function. This
shooting algorithm is locally quadratically convergent if the derivative of the
shooting function is one-to-one at the solution. The main result of this paper
is to show that the latter holds whenever a sufficient condition for weak
optimality is satisfied. We note that this condition is very close to a second
order necessary condition. For the case when the shooting system can be reduced
to one having the same number of unknowns and equations (square system) we
prove that the mentioned sufficient condition guarantees the stability of the
optimal solution under small perturbations and the invertibility of the
Jacobian matrix of the shooting function associated to the perturbed problem.
We present numerical tests that validate our method.Comment: No. RR-7763 (2011); Journal of Optimization, Theory and Applications,
published as 'Online first', January 201
Milagrito: a TeV air-shower array
Milagrito, a large, covered water-Cherenkov detector, was the world's first
air-shower-particle detector sensitive to cosmic gamma rays below 1 TeV. It
served as a prototype for the Milagro detector and operated from February 1997
to May 1998. This paper gives a description of Milagrito, a summary of the
operating experience, and early results that demonstrate the capabilities of
this technique.Comment: 38 pages including 24 figure
The Intentional Use of Service Recovery Strategies to Influence Consumer Emotion, Cognition and Behaviour
Service recovery strategies have been identified as a critical factor in the success of. service organizations. This study develops a conceptual frame work to investigate how specific service recovery strategies influence the emotional, cognitive and negative behavioural responses of . consumers., as well as how emotion and cognition influence negative behavior. Understanding the impact of specific service recovery strategies will allow service providers' to more deliberately and intentionally engage in strategies that result in positive organizational outcomes. This study was conducted using a 2 x 2 between-subjects quasi-experimental design. The results suggest that service recovery has a significant impact on emotion, cognition and negative behavior. Similarly, satisfaction, negative emotion and positive emotion all influence negative behavior but distributive justice has no effect
Neutralino Dark Matter, b-tau Yukawa Unification and Non-Universal Sfermion Masses
We study the implications of minimal non-Universal Boundary Conditions in the
sfermion Soft SUSY Breaking (SSB) masses of mSUGRA. We impose asymptotic b-tau
Yukawa coupling Unification and we resort to a parameterization of the
deviation from Universality in the SSB motivated by the multiplet structure of
SU(5) GUT. A set of cosmo-phenomenological constraints, including the recent
results from WMAP, determines the allowed parameter space of the models under
consideration. We highlight a new coannihilation corridor where
neutralino-sbottom and neutralino-tau sneutrino-stau coannihilations
significantly contribute to the reduction of the neutralino relic density.Comment: 38 pages, 27 Figures, Latex; Version accepted for publication in PR
Damage estimates from long-term structural analysis of a wind turbine in a U.S. wind farm environment
Signatures of Baryon non-conserving Yukawa couplings in a supersymmetric theory
Renormalization effects of large baryon-nonconserving Yukawa couplings
lower the right handed squark masses keeping the left-handed squark masses
virtually untouched at the lowest order. At low energy they enhance the
mass-splitting between left and right handed squarks of the same generation as
well as intergenerational mass splitting among squarks, potentially detectable
in future colliders or in rare decays. The predicted mass of the lightest stop
squark becomes lower than the experimental bound for larger ranges of parameter
space than that of the Baryon-conserving case, hence, further constraining the
parameter space of a supersymmetric theory when baryon violation is included.Comment: 16 pages, six figures, captions.sty include
Higgs Boson Physics in the -channel at Colliders
Techniques and strategies for discovering and measuring the properties of
Higgs bosons via -channel production at a collider, and the
associated requirements for the machine and detector, are discussed in detail.
The unique feature of -channel production is that, with good energy
resolution, the mass, total width and partial widths of a Higgs boson can be
directly measured with remarkable accuracy in most cases. For the expected
machine parameters and luminosity the Standard Model (SM) Higgs boson \hsm,
with mass \lsim 2\mw, the light \hl of the minimal supersymmetric Standard
Model (MSSM), and the heavier MSSM Higgs bosons (the CP-odd \ha and the
CP-even \hh) can all be studied in the -channel, with the heavier states
accessible up to the maximal over a large fraction of the MSSM
parameter space. In addition, it may be possible to discover the \ha and
\hh by running the collider at full energy and observing excess events in the
bremsstrahlung tail at lower energy. The integrated luminosity, beam resolution
and machine/detector features required to distinguish between the \hsm and
\hl are delineated.Comment: 87 pages, uuencoded tex file and postscript figure files submitted,
full postscript file, including embedded figures, is available via anonymous
ftp at ftp://ucdhep.ucdavis.edu/gunion/higgs_mupmum.p
The exposure of the hybrid detector of the Pierre Auger Observatory
The Pierre Auger Observatory is a detector for ultra-high energy cosmic rays.
It consists of a surface array to measure secondary particles at ground level
and a fluorescence detector to measure the development of air showers in the
atmosphere above the array. The "hybrid" detection mode combines the
information from the two subsystems. We describe the determination of the
hybrid exposure for events observed by the fluorescence telescopes in
coincidence with at least one water-Cherenkov detector of the surface array. A
detailed knowledge of the time dependence of the detection operations is
crucial for an accurate evaluation of the exposure. We discuss the relevance of
monitoring data collected during operations, such as the status of the
fluorescence detector, background light and atmospheric conditions, that are
used in both simulation and reconstruction.Comment: Paper accepted by Astroparticle Physic
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