4,785 research outputs found
Optimal properties of some Bayesian inferences
Relative surprise regions are shown to minimize, among Bayesian credible
regions, the prior probability of covering a false value from the prior. Such
regions are also shown to be unbiased in the sense that the prior probability
of covering a false value is bounded above by the prior probability of covering
the true value. Relative surprise regions are shown to maximize both the Bayes
factor in favor of the region containing the true value and the relative belief
ratio, among all credible regions with the same posterior content. Relative
surprise regions emerge naturally when we consider equivalence classes of
credible regions generated via reparameterizations.Comment: Published in at http://dx.doi.org/10.1214/07-EJS126 the Electronic
Journal of Statistics (http://www.i-journals.org/ejs/) by the Institute of
Mathematical Statistics (http://www.imstat.org
On Az\'ema-Yor processes, their optimal properties and the Bachelier-drawdown equation
We study the class of Az\'ema-Yor processes defined from a general
semimartingale with a continuous running maximum process. We show that they
arise as unique strong solutions of the Bachelier stochastic differential
equation which we prove is equivalent to the drawdown equation. Solutions of
the latter have the drawdown property: they always stay above a given function
of their past maximum. We then show that any process which satisfies the
drawdown property is in fact an Az\'ema-Yor process. The proofs exploit group
structure of the set of Az\'ema-Yor processes, indexed by functions, which we
introduce. We investigate in detail Az\'ema-Yor martingales defined from a
nonnegative local martingale converging to zero at infinity. We establish
relations between average value at risk, drawdown function, Hardy-Littlewood
transform and its inverse. In particular, we construct Az\'ema-Yor martingales
with a given terminal law and this allows us to rediscover the Az\'ema-Yor
solution to the Skorokhod embedding problem. Finally, we characterize
Az\'ema-Yor martingales showing they are optimal relative to the concave
ordering of terminal variables among martingales whose maximum dominates
stochastically a given benchmark.Comment: Published in at http://dx.doi.org/10.1214/10-AOP614 the Annals of
Probability (http://www.imstat.org/aop/) by the Institute of Mathematical
Statistics (http://www.imstat.org
Optimal embeddings of ultradistributions into differential algebras
We construct embeddings of spaces of non-quasianalytic ultradistributions into differential algebras enjoying optimal properties in view of a Schwartz type impossibility result, also shown in this article. We develop microlocal analysis in these algebras consistent with the microlocal analysis in the corresponding spaces of ultradistributions
Multidimensional Binning Techniques for a Two Parameter Trilinear Gauge Coupling Estimation at LEP II
This paper describes two generalization schemes of the Optimal Variables
technique in estimating simultaneously two Trilinear Gauge Couplings. The first
is an iterative procedure to perform a 2-dimensional fit using the linear terms
of the expansion of the probability density function with respect to the
corresponding couplings, whilst the second is a clustering method of
probability distribution representation in five dimensions. The pair production
of W's at 183 GeV center of mass energy, where one W decays leptonically and
the other hadronically, was used to demonstrate the optimal properties of the
proposed estimation techniques.Comment: (25 pages, 11 figures
A First Mass Production of Gas Electron Multipliers
We report on the manufacture of a first batch of approximately 2,000 Gas
Electron Multipliers (GEMs) using 3M's fully automated roll to roll flexible
circuit production line. This process allows low-cost, reproducible fabrication
of a high volume of GEMs of dimensions up to 3030 cm. First tests
indicate that the resulting GEMs have optimal properties as radiation
detectors. Production techniques and preliminary measurements of GEM
performance are described. This now demonstrated industrial capability should
help further establish the prominence of micropattern gas detectors in
accelerator based and non-accelerator particle physics, imaging and
photodetection.Comment: 11 pages, 10 figures, to be submitted to Nucl. Instr. Meth.
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