3,896 research outputs found
Spaceability in Banach and quasi-Banach sequence spaces
Let be a Banach space. We prove that, for a large class of Banach or
quasi-Banach spaces of -valued sequences, the sets , where is any subset of , and
contain closed infinite-dimensional subspaces of (if
non-empty, of course). This result is applied in several particular cases and
it is also shown that the same technique can be used to improve a result on the
existence of spaces formed by norm-attaining linear operators.Comment: 9 page
On a Gibbs sampler based random process in Bayesian nonparametrics
We define and investigate a new class of measure-valued Markov chains by resorting to ideas formulated in Bayesian nonparametrics related to the Dirichlet process and the Gibbs sampler. Dependent random probability measures in this class are shown to be stationary and ergodic with respect to the law of a Dirichlet process and to converge in distribution to the neutral diffusion model.Random probability measure; Dirichlet process; Blackwell-MacQueen PĂłlya urn scheme; Gibbs sampler; Bayesian nonparametrics
Fast method for the determination of short-chain-length polyhydroxyalkanoates (scl-PHAs) in bacterial samples by In Vial-Thermolysis (IVT)
none8siA new method based on the GCâMS analysis of thermolysis products obtained by treating bacterial
samples at a high temperature (above 270 C) has been developed. This method, here named âIn-Vial-
Thermolysisâ (IVT), allowed for the simultaneous determination of short-chain-length polyhydrox-
yalkanoates (scl-PHA) content and composition. The method was applied to both single strains and
microbial mixed cultures (MMC) fed with different carbon sources.
The IVT procedure provided similar analytical performances compared to previous Py-GCâMS and Py-
GC-FID methods, suggesting a similar application for PHA quantitation in bacterial cells. Results from the
IVT procedure and the traditional methanolysis method were compared; the correlation between the
two datasets was
fit for the purpose, giving a R2 of 0.975. In search of further simplification, the rationale
of IVT was exploited for the development of a âfield methodâ based on the titration of thermolyzed
samples with sodium hydrogen carbonate to quantify PHA inside bacterial cells. The accuracy of the IVT
method was
fit for the purpose.
These results lead to the possibility for the on-line measurement of PHA productivity. Moreover, they
allow for the fast and inexpensive quantification/characterization of PHA for biotechnological process
control, as well as investigation over various bacterial communities and/or feeding strategies.mixedF. Abbondanzi; G. Biscaro; G. Carvalho; L. Favaro; P. Lemos; M. Paglione; C. SamorĂŹ; C. TorriF. Abbondanzi; G. Biscaro; G. Carvalho; L. Favaro; P. Lemos; M. Paglione; C. SamorĂŹ; C. Torr
A class of measure-valued Markov chains and Bayesian nonparametrics
Measure-valued Markov chains have raised interest in Bayesian nonparametrics
since the seminal paper by (Math. Proc. Cambridge Philos. Soc. 105 (1989)
579--585) where a Markov chain having the law of the Dirichlet process as
unique invariant measure has been introduced. In the present paper, we propose
and investigate a new class of measure-valued Markov chains defined via
exchangeable sequences of random variables. Asymptotic properties for this new
class are derived and applications related to Bayesian nonparametric mixture
modeling, and to a generalization of the Markov chain proposed by (Math. Proc.
Cambridge Philos. Soc. 105 (1989) 579--585), are discussed. These results and
their applications highlight once again the interplay between Bayesian
nonparametrics and the theory of measure-valued Markov chains.Comment: Published in at http://dx.doi.org/10.3150/11-BEJ356 the Bernoulli
(http://isi.cbs.nl/bernoulli/) by the International Statistical
Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm
Motion deblurring of faces
Face analysis is a core part of computer vision, in which remarkable progress
has been observed in the past decades. Current methods achieve recognition and
tracking with invariance to fundamental modes of variation such as
illumination, 3D pose, expressions. Notwithstanding, a much less standing mode
of variation is motion deblurring, which however presents substantial
challenges in face analysis. Recent approaches either make oversimplifying
assumptions, e.g. in cases of joint optimization with other tasks, or fail to
preserve the highly structured shape/identity information. Therefore, we
propose a data-driven method that encourages identity preservation. The
proposed model includes two parallel streams (sub-networks): the first deblurs
the image, the second implicitly extracts and projects the identity of both the
sharp and the blurred image in similar subspaces. We devise a method for
creating realistic motion blur by averaging a variable number of frames to
train our model. The averaged images originate from a 2MF2 dataset with 10
million facial frames, which we introduce for the task. Considering deblurring
as an intermediate step, we utilize the deblurred outputs to conduct a thorough
experimentation on high-level face analysis tasks, i.e. landmark localization
and face verification. The experimental evaluation demonstrates the superiority
of our method
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