3,377 research outputs found
A Posteriori Probabilistic Bounds of Convex Scenario Programs with Validation Tests
Scenario programs have established themselves as efficient tools towards
decision-making under uncertainty. To assess the quality of scenario-based
solutions a posteriori, validation tests based on Bernoulli trials have been
widely adopted in practice. However, to reach a theoretically reliable
judgement of risk, one typically needs to collect massive validation samples.
In this work, we propose new a posteriori bounds for convex scenario programs
with validation tests, which are dependent on both realizations of support
constraints and performance on out-of-sample validation data. The proposed
bounds enjoy wide generality in that many existing theoretical results can be
incorporated as particular cases. To facilitate practical use, a systematic
approach for parameterizing a posteriori probability bounds is also developed,
which is shown to possess a variety of desirable properties allowing for easy
implementations and clear interpretations. By synthesizing comprehensive
information about support constraints and validation tests, improved risk
evaluation can be achieved for randomized solutions in comparison with existing
a posteriori bounds. Case studies on controller design of aircraft lateral
motion are presented to validate the effectiveness of the proposed a posteriori
bounds
\Lambda_b Lifetime from the HQET Sum Rule
The HQET sum rule analysis for the \Lambda_b matrix element of the four-quark
operator relevant to its lifetime is reported. Our main conclusion is that the
lifetime ratio \tau(\Lambda_b)/\tau(B^0) can be as low as 0.91.Comment: 5 pages, latex, no figures, uses sprocl.sty (included). Talk by C.
Liu at Int. Conf. on Flavor Phys., Zhang-Jia-Jie, 31/5-6/6 200
g-2 in composite models of leptons
Based on the bound state description of the muon and general relativistic
covariant quantum field theory, we illustrate with a simple composite model
that the observed deviation of (g-2)_\mu can be a demonstration of the
substructure of the muon and give the constraints on the radius of the muon in
different cases of light constituents and heavy constituents.Comment: 14 pages, 4 eps figures, revtex, several arguments and some
references renewe
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