1,213 research outputs found
On distinguishability, orthogonality, and violations of the second law: contradictory assumptions, contrasting pieces of knowledge
Two statements by von Neumann and a thought-experiment by Peres prompts a
discussion on the notions of one-shot distinguishability, orthogonality,
semi-permeable diaphragm, and their thermodynamic implications. In the first
part of the paper, these concepts are defined and discussed, and it is
explained that one-shot distinguishability and orthogonality are contradictory
assumptions, from which one cannot rigorously draw any conclusion, concerning
e.g. violations of the second law of thermodynamics. In the second part, we
analyse what happens when these contradictory assumptions comes, instead, from
_two_ different observers, having different pieces of knowledge about a given
physical situation, and using incompatible density matrices to describe it.Comment: LaTeX2e/RevTeX4, 18 pages, 6 figures. V2: Important revisio
Numerical Bayesian state assignment for a three-level quantum system. I. Absolute-frequency data; constant and Gaussian-like priors
This paper offers examples of concrete numerical applications of Bayesian
quantum-state-assignment methods to a three-level quantum system. The
statistical operator assigned on the evidence of various measurement data and
kinds of prior knowledge is computed partly analytically, partly through
numerical integration (in eight dimensions) on a computer. The measurement data
consist in absolute frequencies of the outcomes of N identical von Neumann
projective measurements performed on N identically prepared three-level
systems. Various small values of N as well as the large-N limit are considered.
Two kinds of prior knowledge are used: one represented by a plausibility
distribution constant in respect of the convex structure of the set of
statistical operators; the other represented by a Gaussian-like distribution
centred on a pure statistical operator, and thus reflecting a situation in
which one has useful prior knowledge about the likely preparation of the
system.
In a companion paper the case of measurement data consisting in average
values, and an additional prior studied by Slater, are considered.Comment: 23 pages, 14 figures. V2: Added an important note concerning
cylindrical algebraic decomposition and thanks to P B Slater, corrected some
typos, added reference
The Laplace-Jaynes approach to induction
An approach to induction is presented, based on the idea of analysing the
context of a given problem into `circumstances'. This approach, fully Bayesian
in form and meaning, provides a complement or in some cases an alternative to
that based on de Finetti's representation theorem and on the notion of infinite
exchangeability. In particular, it gives an alternative interpretation of those
formulae that apparently involve `unknown probabilities' or `propensities'.
Various advantages and applications of the presented approach are discussed,
especially in comparison to that based on exchangeability. Generalisations are
also discussed.Comment: 38 pages, 1 figure. V2: altered discussion on some points, corrected
typos, added reference
Numerical Bayesian quantum-state assignment for a three-level quantum system. II. Average-value data with a constant, a Gaussian-like, and a Slater prior
This paper offers examples of concrete numerical applications of Bayesian
quantum-state assignment methods to a three-level quantum system. The
statistical operator assigned on the evidence of various measurement data and
kinds of prior knowledge is computed partly analytically, partly through
numerical integration (in eight dimensions) on a computer. The measurement data
consist in the average of outcome values of N identical von Neumann projective
measurements performed on N identically prepared three-level systems. In
particular the large-N limit will be considered. Three kinds of prior knowledge
are used: one represented by a plausibility distribution constant in respect of
the convex structure of the set of statistical operators; another one
represented by a prior studied by Slater, which has been proposed as the
natural measure on the set of statistical operators; the last prior is
represented by a Gaussian-like distribution centred on a pure statistical
operator, and thus reflecting a situation in which one has useful prior
knowledge about the likely preparation of the system. The assigned statistical
operators obtained with the first two kinds of priors are compared with the one
obtained by Jaynes' maximum entropy method for the same measurement situation.
In the companion paper the case of measurement data consisting in absolute
frequencies is considered.Comment: 10 pages, 4 figures. V2: added "Post scriptum" under Conclusions,
slightly changed Acknowledgements, and corrected some spelling error
Cosmic variance of the galaxy cluster weak lensing signal
Intrinsic variations of the projected density profiles of clusters of
galaxies at fixed mass are a source of uncertainty for cluster weak lensing. We
present a semi-analytical model to account for this effect, based on a
combination of variations in halo concentration, ellipticity and orientation,
and the presence of correlated haloes. We calibrate the parameters of our model
at the 10 per cent level to match the empirical cosmic variance of cluster
profiles at M_200m=10^14...10^15 h^-1 M_sol, z=0.25...0.5 in a cosmological
simulation. We show that weak lensing measurements of clusters significantly
underestimate mass uncertainties if intrinsic profile variations are ignored,
and that our model can be used to provide correct mass likelihoods. Effects on
the achievable accuracy of weak lensing cluster mass measurements are
particularly strong for the most massive clusters and deep observations (with
~20 per cent uncertainty from cosmic variance alone at M_200m=10^15 h^-1 M_sol
and z=0.25), but significant also under typical ground-based conditions. We
show that neglecting intrinsic profile variations leads to biases in the
mass-observable relation constrained with weak lensing, both for intrinsic
scatter and overall scale (the latter at the 15 per cent level). These biases
are in excess of the statistical errors of upcoming surveys and can be avoided
if the cosmic variance of cluster profiles is accounted for.Comment: 14 pages, 6 figures; submitted to MNRA
A Creative Review on Integer Additive Set-Valued Graphs
For a non-empty ground set , finite or infinite, the {\em set-valuation}
or {\em set-labeling} of a given graph is an injective function , where is the power set of the set . A
set-indexer of a graph is an injective set-valued function such that the function defined by for
every is also injective, where is a binary operation on
sets. An integer additive set-indexer is defined as an injective function
such that the induced function
defined by is
also injective, where is the set of all non-negative integers.
In this paper, we critically and creatively review the concepts and properties
of integer additive set-valued graphs.Comment: 14 pages, submitted. arXiv admin note: text overlap with
arXiv:1312.7672, arXiv:1312.767
Detection of Methicillin-Resistant Staphylococcus aureus (MRSA) Using Loop Mediated Isothermal Amplification (LAMP)
Staphylococcus aureus is one of the most common pathogens that cause a wide
range of infections ranging from skin and soft tissue infections to invasive, life
threatening infections. The emergence of methicillin-resistant Staphylococcus aureus
(MRSA) substantially increased healthcare burdens associated with Staphylococcal
infections because of high morbidity and mortality and increasing the need for efficient
and cost-effective screening methods, for high-risk patients. The objective of this study
is to develop two molecular methods, real-time PCR and loop-mediated isothermal
amplification (LAMP), and validate them following Clinical Laboratory Improvement
Amendments (CLIA) and College of American Pathologists (CAP) standards. The real
time PCR assay was developed targeting mecA, mecC, nuc, and coa to detect S. aureus
and methicillin-resistance. The assay had high precision, a linear range of 104-108
CFU/ml, and 95% accuracy. The assay detects MRSA, MSSA, MR-CoNS, and MS
CoNS. The LAMP assay was developed targeting the same genes; however, its lower
limit of detection was 106 CFU/ml, which was much higher than that of the real-time
PCR assay. Additional studies are required to optimize the performance characteristics
of the LAMP assay further. Nevertheless, the real-time PCR assay developed in this
study will be useful for the detection of MRSA in a cost-effective manner
Strong Integer Additive Set-valued Graphs: A Creative Review
For a non-empty ground set , finite or infinite, the {\em set-valuation}
or {\em set-labeling} of a given graph is an injective function , where is the power set of the set . A
set-indexer of a graph is an injective set-valued function such that the function defined by for
every is also injective., where is a binary operation on
sets. An integer additive set-indexer is defined as an injective function
such that the induced function
defined by is
also injective, where is the set of all non-negative integers
and is its power set. An IASI is said to be a
strong IASI if for every pair of adjacent vertices
in . In this paper, we critically and creatively review the concepts
and properties of strong integer additive set-valued graphs.Comment: 13 pages, Published. arXiv admin note: text overlap with
arXiv:1407.4677, arXiv:1405.4788, arXiv:1310.626
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