239 research outputs found
Entropy estimate of probability densities having assigned moments: Hausdorff case
AbstractConsidered here are absolutely continuous probability distributions, concentrated on the interval [0, 1], and with the first M algebraic moments assigned. Lower and upper bounds for entropy are provided solely in terms of assigned moments
Presentazione
Presentazione del numero monografico della rivista "Linguae &", dedicato ai risultati del corso di alta formazione \u201cCostruire l\u2019Europa: lingue, culture e letterature dal Medioevo alle Modernit\ue0\u201d, rivolto a docenti di scuole secondarie e a giovani studiosi e dedicato ad approfondire il ruolo delle discipline umanistiche, prime fra tutte la filologia romanza, nella fondazione del concetto di Europa, con particolare riguardo alle sue declinazioni linguistiche, letterarie e culturali, tenutosi a Urbino dal 17 al 21 luglio 2017
Statistical properties of acoustic emission signals from metal cutting processes
Acoustic Emission (AE) data from single point turning machining are analysed
in this paper in order to gain a greater insight of the signal statistical
properties for Tool Condition Monitoring (TCM) applications. A statistical
analysis of the time series data amplitude and root mean square (RMS) value at
various tool wear levels are performed, �nding that ageing features can
be revealed in all cases from the observed experimental histograms. In
particular, AE data amplitudes are shown to be distributed with a power-law
behaviour above a cross-over value. An analytic model for the RMS values
probability density function (pdf) is obtained resorting to the Jaynes' maximum
entropy principle (MEp); novel technique of constraining the modelling function
under few fractional moments, instead of a greater amount of ordinary moments,
leads to well-tailored functions for experimental histograms.Comment: 16 pages, 7 figure
Towards standardisation:comparison of five whole genome sequencing (WGS) analysis pipelines for detection of epidemiologically linked tuberculosis cases
BackgroundWhole genome sequencing (WGS) is a reliable tool for studying tuberculosis (TB) transmission. WGS data are usually processed by custom-built analysis pipelines with little standardisation between them.AimTo compare the impact of variability of several WGS analysis pipelines used internationally to detect epidemiologically linked TB cases.MethodsFrom the Netherlands, 535 Mycobacterium tuberculosis complex (MTBC) strains from 2016 were included. Epidemiological information obtained from municipal health services was available for all mycobacterial interspersed repeat unit-variable number of tandem repeat (MIRU-VNTR) clustered cases. WGS data was analysed using five different pipelines: one core genome multilocus sequence typing (cgMLST) approach and four single nucleotide polymorphism (SNP)-based pipelines developed in Oxford, United Kingdom; Borstel, Germany; Bilthoven, the Netherlands and Copenhagen, Denmark. WGS clusters were defined using a maximum pairwise distance of 12 SNPs/alleles.ResultsThe cgMLST approach and Oxford pipeline clustered all epidemiologically linked cases, however, in the other three SNP-based pipelines one epidemiological link was missed due to insufficient coverage. In general, the genetic distances varied between pipelines, reflecting different clustering rates: the cgMLST approach clustered 92 cases, followed by 84, 83, 83 and 82 cases in the SNP-based pipelines from Copenhagen, Oxford, Borstel and Bilthoven respectively.ConclusionConcordance in ruling out epidemiological links was high between pipelines, which is an important step in the international validation of WGS data analysis. To increase accuracy in identifying TB transmission clusters, standardisation of crucial WGS criteria and creation of a reference database of representative MTBC sequences would be advisable
Multivariate truncated moments problems and maximum entropy
We characterize the existence of the Lebesgue integrable solutions of the
truncated problem of moments in several variables on unbounded supports by the
existence of some maximum entropy -- type representing densities and discuss a
few topics on their approximation in a particular case, of two variables and
4th order moments.Comment: Revised version, to appear in Analysis and Mathematical Physic
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