scholarly journals Optimal Shadowing Filter for a Positioning and Tracking Methodology with Limited Information

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 931 ◽  
Author(s):  
Ayham Zaitouny ◽  
Thomas Stemler ◽  
Shannon Algar
Keyword(s):  
Phase Space ◽  
Real Life ◽  
Positional Information ◽  
Irregular Sampling ◽  
Moving Target ◽  
Limited Information ◽  
Uncorrelated Noise ◽  
Full Phase Space

Positioning and tracking a moving target from limited positional information is a frequently-encountered problem. For given noisy observations of the target’s position, one wants to estimate the true trajectory and reconstruct the full phase space including velocity and acceleration. The shadowing filter offers a robust methodology to achieve such an estimation and reconstruction. Here, we highlight and validate important merits of this methodology for real-life applications. In particular, we explore the filter’s performance when dealing with correlated or uncorrelated noise, irregular sampling in time and how it can be optimised even when the true dynamics of the system are not known.

scholarly journals The Impact of Multidisciplinary Discussion (MDD) in the Diagnosis and Management of Fibrotic Interstitial Lung Diseases

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Ghofran Ageely ◽  
Carolina Souza ◽  
Kaissa De Boer ◽  
Saly Zahra ◽  
Marcio Gomes ◽  
...  
Keyword(s):  
Lung Diseases ◽  
Significant Proportion ◽  
Real Life ◽  
Interstitial Lung Diseases ◽  
Limited Information ◽  
Reference Standard ◽  
Provisional Diagnosis ◽  
Surgical Biopsy ◽  
Academic Center ◽  
The Impact

Accurate diagnosis of interstitial lung disease (ILD) is crucial for management and prognosis but can be challenging even for experienced clinicians. Expert multidisciplinary discussion (MDD) is considered the reference standard for ILD diagnosis; however, there remain concerns regarding lack of validation studies and relative limited information on the impact of MDD in real-life clinical practice. The goal of this study was to assess the effect of MDD in providing a specific ILD diagnosis, changing the diagnosis provided upon referral, and to determine how often and in which way MDD altered management. Material and Methods. Retrospective observational study in an ILD referral tertiary academic center. MDD diagnoses were categorized as specific, provisional, and unclassifiable ILD. Pre-MDD and MDD diagnoses were compared for change in diagnosis and concordance rates for specific diagnoses. Relevant change in management including initiation or change in pharmacological treatment, referral to surgical biopsy, and nonpharmacological management were recorded. Results. 126 cases were included (79M, 47F, 36–93 years, mean 70 y). Specific MDD diagnosis was provided in 62% (78/126); 12% (15/126) had provisional diagnosis, and 21% (27/126) was unclassifiable. Overall agreement for specific pre-MDD and MDD diagnosis was 41% (52/126) and 80% for idiopathic pulmonary fibrosis (IPF) diagnosis. MDD altered diagnosis in 37% (47/126) and changed management in 39% (50/126). Amongst concordant diagnoses, management was altered in 46% (24/52). In summary, MDD provided a specific diagnosis discordant with pre-MDD diagnosis in a significant proportion of cases and was particularly valuable in the diagnosis of non-IPF ILD. MDD often altered management and had relevant impact on management even in cases with concordant pre-MDD diagnosis.

scholarly journals Leaves on trees: identifying halo stars with extreme gradient boosted trees

2018 ◽  
Vol 621 ◽  
pp. A13 ◽  
Author(s):  
Jovan Veljanoski ◽  
Amina Helmi ◽  
Maarten Breddels ◽  
Lorenzo Posti
Keyword(s):  
Phase Space ◽  
New Era ◽  
Massive Galaxies ◽  
Full Phase Space ◽  
Halo Stars ◽  
Machine Learning Model ◽  
Data Release ◽  
Stellar Halo ◽  
Red Giant ◽  
Galactic Astronomy

Context. Extended stellar haloes are a natural by-product of the hierarchical formation of massive galaxies like the Milky Way. If merging is a non-negligible factor in the growth of our Galaxy, evidence of such events should be encoded in its stellar halo. The reliable identification of genuine halo stars is a challenging task, however. Aims. With the advent of the Gaia space telescope, we are ushered into a new era of Galactic astronomy. The first Gaia data release contains the positions, parallaxes, and proper motions for over two million stars, mostly in the solar neighbourhood. The second Gaia data release will enlarge this sample to over 1.5 billion stars, the brightest ~ 5 million of which will have full phase-space information. Our aim for this paper is to develop a machine learning model for reliably identifying halo stars, even when their full phase-space information is not available. Methods. We use the Gradient Boosted Trees algorithm to build a supervised halo star classifier. The classifier is trained on a sample of stars extracted from the Gaia Universe Model Snapshot, which is also convolved with the errors of the public TGAS data, which is a subset of Gaia DR1, as well as with the expected uncertainties for the upcoming Gaia DR2 catalogue. We also trained our classifier on a dataset resulting from the cross-match between the TGAS and RAVE catalogues, where the halo stars are labelled in an entirely model-independent way. We then use this model to identify halo stars in TGAS. Results. When full phase-space information is available and for Gaia DR2-like uncertainties, our classifier is able to recover 90% of the halo stars with at most 30% distance errors, in a completely unseen test set and with negligible levels of contamination. When line-of-sight velocity is not available, we recover ~ 60% of such halo stars, with less than 10% contamination. When applied to the TGAS catalogue, our classifier detects 337 high confidence red giant branch halo stars. At first glance this number may seem small, however, it is consistent with the expectation from the models, given the uncertainties in the data. The large parallax errors are in fact the biggest limitation in our ability to identify a large number of halo stars in all the cases studied.

scholarly journals Charged-Particle Multiplicity Moments as Described by Shifted Gompertz Distribution in e+e−, pp¯, and pp Collisions at High Energies

2020 ◽  
Vol 2020 ◽  
pp. 1-24
Author(s):  
Aayushi Singla ◽  
M. Kaur
Keyword(s):  
Charged Particle ◽  
Phase Space ◽  
Center Of Mass ◽  
Particle Multiplicity ◽  
Charged Particle Multiplicity ◽  
Distribution Analysis ◽  
Factorial Moments ◽  
Hadronic Interactions ◽  
Gompertz Distribution ◽  
Full Phase Space

In continuation of our earlier work, in which we analysed the charged particle multiplicities in leptonic and hadronic interactions at different center-of-mass energies in full phase space as well as in restricted phase space using the shifted Gompertz distribution, a detailed analysis of the normalized moments and normalized factorial moments is reported here. A two-component model in which a probability distribution function is obtained from the superposition of two shifted Gompertz distributions, as introduced in our earlier work, has also been used for the analysis. This is the first analysis of the moments with the shifted Gompertz distribution. Analysis has also been performed to predict the moments of multiplicity distribution for the e+e− collisions at s=500 GeV at a future collider.

scholarly journals Entropy Analysis in Relativistic Heavy-Ion Collisions

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Shakeel Ahmad ◽  
A. Ahmad ◽  
Anuj Chandra ◽  
M. Zafar ◽  
M. Irfan
Keyword(s):  
Phase Space ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collisions ◽  
Strong Correlations ◽  
Entropy Analysis ◽  
Multiphase Transport ◽  
Long Range Correlations ◽  
Ion Collisions ◽  
Full Phase Space ◽  
Multiparticle System

Entropy creation in multiparticle system is investigated by analysing the experimental data on ion-ion collisions at AGS and SPS energies and the results thus obtained are compared with those predicted by multiphase transport and correlation-free Monte Carlo models. Entropies produced in limited- and full-phase space are observed to increase with increasing beam energy. The entropy values, normalized to the maximum rapidity and plotted against pseudorapidity (bin width also normalized to the maximum rapidity), are found to be energy independent, exhibiting a kind of entropy scaling. Such scaling is observed in the full phase space as well as in the regions confined to the forward or backward hemispheres. The findings also reveal that there exist strong correlations amongst the particles produced in the forward and backward hemispheres around the midrapidity. These correlations are found to be of short range in nature, and the contributions from the long-range correlations seem to be absent. PACS numbers: 25.75-q, 25.75.Gz.

scholarly journals Measurements of $${\Xi \left( 1530\right) ^{0}} $$ and $${\overline{\Xi }\left( 1530\right) ^{0}} $$ production in proton–proton interactions at $$\sqrt{s_{NN}}$$ = 17.3 $$\text{ GeV }$$ in the NA61/SHINE experiment

2021 ◽  
Vol 81 (10) ◽  
Author(s):  
A. Acharya ◽  
H. Adhikary ◽  
K. K. Allison ◽  
N. Amin ◽  
E. V. Andronov ◽  
...  
Keyword(s):  
Phase Space ◽  
Transverse Momentum ◽  
Statistical Model ◽  
Beam Momentum ◽  
Proton Proton ◽  
Model Calculations ◽  
Full Phase Space ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra

AbstractDouble-differential yields of $${\Xi \left( 1530\right) ^{0}} $$ Ξ 1530 0 and $${\overline{\Xi }\left( 1530\right) ^{0}} $$ Ξ ¯ 1530 0 resonances produced in p+p interactions were measured at a laboratory beam momentum of 158 $$\text{ GeV }\!/\!c$$ GeV / c . This measurement is the first of its kind in p+p interactions below LHC energies. It was performed at the CERN SPS by the NA61/SHINE collaboration. Double-differential distributions in rapidity and transverse momentum were obtained from a sample of $$26\times 10^6$$ 26 × 10 6 inelastic events. The spectra are extrapolated to full phase space resulting in mean multiplicity of $${\Xi \left( 1530\right) ^{0}} $$ Ξ 1530 0 ($$6.73 \pm 0.25\pm 0.67)\times 10^{-4}$$ 6.73 ± 0.25 ± 0.67 ) × 10 - 4 and $${\overline{\Xi }\left( 1530\right) ^{0}} $$ Ξ ¯ 1530 0 ($$2.71 \pm 0.18\pm 0.18)\times 10^{-4}$$ 2.71 ± 0.18 ± 0.18 ) × 10 - 4 . The rapidity and transverse momentum spectra and mean multiplicities were compared to predictions of string-hadronic and statistical model calculations.

scholarly journals Real-life evaluation of a rapid antigen test (Panbio™ COVID-19 Ag Rapid Test Device) for SARS-CoV-2 detection in asymptomatic close contacts of COVID-19 patients

2020 ◽  
Author(s):  
Ignacio Torres ◽  
Sandrine Poujois ◽  
Eliseo Albert ◽  
Javier Colomina ◽  
David Navarro
Keyword(s):  
Point Of Care ◽  
Real Life ◽  
Rapid Test ◽  
Optimal Timing ◽  
Upper Respiratory Tract ◽  
Limited Information ◽  
Rt Pcr ◽  
Test Device ◽  
Household Contacts ◽  
Close Contacts

ABSTRACTObjectivesThere is limited information on the performance of rapid antigen detection (RAD) tests to identify SARS-CoV-2-infected asymptomatic individuals. In this field study, we evaluated the Panbio™ COVID-19 Ag Rapid Test Device (Abbott Diagnostics, Jena, Germany) for the purpose.MethodsA total of 634 individuals (355 female; median age, 37 years; range, 9-87) were enrolled. Household (n=338) contacts were tested at a median of 2 days (range, 1-7) after diagnosis of the index case and non-household contacts (n=296) at a median of 6 days (range, 1-7) after exposure. RAD testing was carried out at the point of care. The RT-PCR test used was the TaqPath COVID-19 Combo Kit (Thermo Fisher Scientific, Massachusetts, USA).ResultsIn total, 79 individuals (12.4%) tested positive by RT-PCR, of whom 38 (48.1%) yielded positive RAD results. The overall sensitivity and specificity of the RAD test was 48.1% (95% CI: 37.4-58.9) and 100% (95% CI: 99.3-100), respectively. Sensitivity was higher in household (50.8%; 95% CI: 38.9-62.5) than in non-household (35.7%; 95% CI:16.3-61.2%) contacts. Individuals testing positive by RAD test were more likely (P<0.001) to become symptomatic than their negative counterparts.ConclusionThe Panbio test displays low sensitivity in asymptomatic close contacts of COVID-19 patients, particularly in non-household contacts. Nonetheless, establishing the optimal timing for upper respiratory tract collection in this group seems imperative to pinpoint test sensitivity.

scholarly journals Higher order QCD effects and particle density in full phase space from highp T interactions at the ISR

1991 ◽  
Vol 52 (4) ◽  
pp. 551-557 ◽  
Author(s):  
◽  
A. Breakstone ◽  
C. D. Buchanan ◽  
R. Campanini ◽  
H. B. Crawley ◽  
...  
Keyword(s):  
Phase Space ◽  
Particle Density ◽  
Higher Order ◽  
Full Phase Space

scholarly journals Impedance-Based Stability Analysis of Paralleled Grid-Connected Rectifiers: Experimental Case Study in a Data Center

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2109 ◽  
Author(s):  
Henrik Alenius ◽  
Tomi Roinila
Keyword(s):  
Stability Analysis ◽  
Data Center ◽  
Large Scale ◽  
Real Life ◽  
System Stability ◽  
Limited Information ◽  
Impedance Measurements ◽  
Grid Connected Converters ◽  
The Stability

Grid-connected systems often consist of several feedback-controlled power-electronics converters that are connected in parallel. Consequently, a number of stability issues arise due to interactions among multiple converter subsystems. Recent studies have presented impedance-based methods to assess the stability of such large systems. However, only few real-life experiences have been previously presented, and practical implementations of impedance-based analysis are rare for large-scale systems that consist of multiple parallel-connected devices. This work presents a case study in which an unstable high-frequency operation, caused by multiple paralleled grid-connected rectifiers, of a 250 kW data center in southern Finland is reported and studied. In addition, the work presents an experimental approach for characterizing and assessing the system stability by using impedance measurements and an aggregated impedance-based analysis. Recently proposed wideband-identification techniques based on binary injection and Fourier methods are applied to obtain the experimental impedance measurements from the input terminals of a single data center rectifier unit. This work provides a practical approach to design and implement the impedance-based stability analysis for a system consisting of multiple paralleled grid-connected converters. It is shown that the applied methods effectively predict the overall system stability and the resonant modes of the system, even with very limited information on the system. The applied methods are versatile, and can be utilized in various grid-connected applications, for example, in adaptive control, system monitoring, and stability analysis.

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