192 research outputs found

    Knowledge structure representation and automated updates in intelligent information management systems

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    A continuing effort to apply rapid prototyping and Artificial Intelligence techniques to problems associated with projected Space Station-era information management systems is examined. In particular, timely updating of the various databases and knowledge structures within the proposed intelligent information management system (IIMS) is critical to support decision making processes. Because of the significantly large amounts of data entering the IIMS on a daily basis, information updates will need to be automatically performed with some systems requiring that data be incorporated and made available to users within a few hours. Meeting these demands depends first, on the design and implementation of information structures that are easily modified and expanded, and second, on the incorporation of intelligent automated update techniques that will allow meaningful information relationships to be established. Potential techniques are studied for developing such an automated update capability and IIMS update requirements are examined in light of results obtained from the IIMS prototyping effort

    Rapid prototyping and AI programming environments applied to payload modeling

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    This effort focused on using artificial intelligence (AI) programming environments and rapid prototyping to aid in both space flight manned and unmanned payload simulation and training. Significant problems addressed are the large amount of development time required to design and implement just one of these payload simulations and the relative inflexibility of the resulting model to accepting future modification. Results of this effort have suggested that both rapid prototyping and AI programming environments can significantly reduce development time and cost when applied to the domain of payload modeling for crew training. The techniques employed are applicable to a variety of domains where models or simulations are required

    A rapid prototyping/artificial intelligence approach to space station-era information management and access

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    Applications of rapid prototyping and Artificial Intelligence techniques to problems associated with Space Station-era information management systems are described. In particular, the work is centered on issues related to: (1) intelligent man-machine interfaces applied to scientific data user support, and (2) the requirement that intelligent information management systems (IIMS) be able to efficiently process metadata updates concerning types of data handled. The advanced IIMS represents functional capabilities driven almost entirely by the needs of potential users. Space Station-era scientific data projected to be generated is likely to be significantly greater than data currently processed and analyzed. Information about scientific data must be presented clearly, concisely, and with support features to allow users at all levels of expertise efficient and cost-effective data access. Additionally, mechanisms for allowing more efficient IIMS metadata update processes must be addressed. The work reported covers the following IIMS design aspects: IIMS data and metadata modeling, including the automatic updating of IIMS-contained metadata, IIMS user-system interface considerations, including significant problems associated with remote access, user profiles, and on-line tutorial capabilities, and development of an IIMS query and browse facility, including the capability to deal with spatial information. A working prototype has been developed and is being enhanced

    Search for Higgs boson decays to a Z boson and a photon in proton-proton collisions at s \sqrt{s} = 13 TeV

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    Results are presented from a search for the Higgs boson decay H→\toZÎł\gamma, where Z→ℓ+ℓ−\to\ell^+\ell^- with ℓ\ell = e or ÎŒ\mu. The search is performed using a sample of proton-proton (pp) collision data at a center-of-mass energy of 13 TeV, recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138 fb−1^{-1}. Events are assigned to mutually exclusive categories, which exploit differences in both event topology and kinematics of distinct Higgs production mechanisms to enhance signal sensitivity. The signal strength ÎŒ\mu, defined as the product of the cross section and the branching fraction [σ(\sigma(pp→\toH)B()\mathcal{B}(H→\toZÎł)\gamma)] relative to the standard model prediction, is extracted from a simultaneous fit to the ℓ+ℓ−γ\ell^+\ell^-\gamma invariant mass distributions in all categories and is found to be ÎŒ\mu=2.4±\pm0.9 for a Higgs boson mass of 125.38 GeV. The statistical significance of the observed excess of events is 2.7 standard deviations. This measurement corresponds to σ(\sigma(pp→\toH)B()\mathcal{B}(H→\toZÎł)\gamma) = 0.21±\pm0.08 pb. The observed (expected) upper limit at 95% confidence level on ÎŒ\mu is 4.1 (1.8). The ratio of branching fractions B(\mathcal{B}(H→\toZÎł)/B(\gamma)/\mathcal{B}(H→γγ)\to\gamma\gamma) is measured to be 1.5−0.6+0.7^{+0.7}_{-0.6}, which agrees with the standard model prediction of 0.69 ±\pm 0.04 at the 1.5 standard deviation level

    Geoeconomic variations in epidemiology, ventilation management, and outcomes in invasively ventilated intensive care unit patients without acute respiratory distress syndrome: a pooled analysis of four observational studies

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    Background: Geoeconomic variations in epidemiology, the practice of ventilation, and outcome in invasively ventilated intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) remain unexplored. In this analysis we aim to address these gaps using individual patient data of four large observational studies. Methods: In this pooled analysis we harmonised individual patient data from the ERICC, LUNG SAFE, PRoVENT, and PRoVENT-iMiC prospective observational studies, which were conducted from June, 2011, to December, 2018, in 534 ICUs in 54 countries. We used the 2016 World Bank classification to define two geoeconomic regions: middle-income countries (MICs) and high-income countries (HICs). ARDS was defined according to the Berlin criteria. Descriptive statistics were used to compare patients in MICs versus HICs. The primary outcome was the use of low tidal volume ventilation (LTVV) for the first 3 days of mechanical ventilation. Secondary outcomes were key ventilation parameters (tidal volume size, positive end-expiratory pressure, fraction of inspired oxygen, peak pressure, plateau pressure, driving pressure, and respiratory rate), patient characteristics, the risk for and actual development of acute respiratory distress syndrome after the first day of ventilation, duration of ventilation, ICU length of stay, and ICU mortality. Findings: Of the 7608 patients included in the original studies, this analysis included 3852 patients without ARDS, of whom 2345 were from MICs and 1507 were from HICs. Patients in MICs were younger, shorter and with a slightly lower body-mass index, more often had diabetes and active cancer, but less often chronic obstructive pulmonary disease and heart failure than patients from HICs. Sequential organ failure assessment scores were similar in MICs and HICs. Use of LTVV in MICs and HICs was comparable (42·4% vs 44·2%; absolute difference -1·69 [-9·58 to 6·11] p=0·67; data available in 3174 [82%] of 3852 patients). The median applied positive end expiratory pressure was lower in MICs than in HICs (5 [IQR 5-8] vs 6 [5-8] cm H2O; p=0·0011). ICU mortality was higher in MICs than in HICs (30·5% vs 19·9%; p=0·0004; adjusted effect 16·41% [95% CI 9·52-23·52]; p<0·0001) and was inversely associated with gross domestic product (adjusted odds ratio for a US$10 000 increase per capita 0·80 [95% CI 0·75-0·86]; p<0·0001). Interpretation: Despite similar disease severity and ventilation management, ICU mortality in patients without ARDS is higher in MICs than in HICs, with a strong association with country-level economic status

    Search for direct pair production of supersymmetric partners of τ\tau leptons in the final state with two hadronically decaying τ\tau leptons and missing transverse momentum in proton-proton collisions at s\sqrt{s} = 13 TeV

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    A search for the direct production of a pair of ττ sleptons, the supersymmetric partners of ττ leptons, is presented. Each ττ slepton is assumed to decay to a ττ lepton and the lightest supersymmetric particle (LSP), which is assumed to be stable and to not interact in the detector, leading to an imbalance in the total reconstructed transverse momentum. The search is carried out in events identified as containing two ττ leptons, each decaying to one or more hadrons and a neutrino, and significant transverse momentum imbalance. In addition to scenarios in which the ττ sleptons decay promptly, the search also addresses scenarios in which the ττ sleptons have sufficiently long lifetimes to give rise to nonprompt ττ leptons. The data were collected in proton-proton collisions at a center-of-mass energy of 13 TeV at the CERN LHC with the CMS detector in 2016–2018, and correspond to an integrated luminosity of 138 fb−1^{-1}. No significant excess is seen with respect to standard model expectations. Upper limits on cross sections for the pair production of ττ sleptons are obtained in the framework of simplified models. In a scenario in which the ττ sleptons are superpartners of left-handed ττ leptons, and each undergoes a prompt decay to a ττ lepton and a nearly massless LSP, ττ slepton masses between 115 and 340 GeV are excluded. In a scenario in which the lifetime of the ττ sleptons corresponds to cτ0cτ_0 = 0.1 mm, where τ0τ_0 represents the mean proper lifetime of the ττ slepton, masses between 150 and 220 GeV are excluded

    Search for nonresonant pair production of highly energetic Higgs bosons decaying to bottom quarks

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    A search for nonresonant Higgs boson (H) pair production via gluon and vector boson (V) fusion is performed in the four-bottom-quark final state, using proton-proton collision data at 13 TeV corresponding to 138 fb−1^{-1} collected by the CMS experiment at the LHC. The analysis targets Lorentz-boosted H pairs identified using a graph neural network. It constrains the strengths relative to the standard model of the H self-coupling and the quartic VVHH couplings, Îș2V{\kappa_{2\mathrm{V}}} , excluding Îș2V={\kappa_{2\mathrm{V}}} = 0 for the first time, with a significance of 6.3 standard deviations when other H couplings are fixed to their standard model values.A search for nonresonant Higgs boson (HH) pair production via gluon and vector boson (VV) fusion is performed in the four-bottom-quark final state, using proton-proton collision data at 13 TeV corresponding to 138 fb−1^{−1} collected by the CMS experiment at the LHC. The analysis targets Lorentz-boosted HH pairs identified using a graph neural network. It constrains the strengths relative to the standard model of the HH self-coupling and the quartic VVHH couplings, Îș2VÎș_{2V}, excluding Îș2V=0Îș_{2V} = 0 for the first time, with a significance of 6.3 standard deviations when other H couplings are fixed to their standard model values.A search for nonresonant Higgs boson (H) pair production via gluon and vector boson (V) fusion is performed in the four-bottom-quark final state, using proton-proton collision data at 13 TeV corresponding to 138  fb-1 collected by the CMS experiment at the LHC. The analysis targets Lorentz-boosted H pairs identified using a graph neural network. It constrains the strengths relative to the standard model of the H self-coupling and the quartic VVHH couplings, Îș2V, excluding Îș2V=0 for the first time, with a significance of 6.3 standard deviations when other H couplings are fixed to their standard model values.A search for nonresonant Higgs boson (HH) pair production via gluon and vector boson (VV) fusion is performed in the four-bottom-quark final state, using proton-proton collision data at 13 TeV corresponding to 138 fb−1^{−1} collected by the CMS experiment at the LHC. The analysis targets Lorentz-boosted HH pairs identified using a graph neural network. It constrains the strengths relative to the standard model of the HH self-coupling and the quartic VVHH couplings, Îș2VÎș_{2V}, excluding Îș2V=0Îș_{2V} = 0 for the first time, with a significance of 6.3 standard deviations when other H couplings are fixed to their standard model values.A search for nonresonant Higgs boson (H) pair production via gluon and vector boson (V) fusion is performed in the four-bottom-quark final state, using proton-proton collision data at 13 TeV corresponding to 138  fb-1 collected by the CMS experiment at the LHC. The analysis targets Lorentz-boosted H pairs identified using a graph neural network. It constrains the strengths relative to the standard model of the H self-coupling and the quartic VVHH couplings, Îș2V, excluding Îș2V=0 for the first time, with a significance of 6.3 standard deviations when other H couplings are fixed to their standard model values.A search for nonresonant Higgs boson (HH) pair production via gluon and vector boson (VV) fusion is performed in the four-bottom-quark final state, using proton-proton collision data at 13 TeV corresponding to 138 fb−1^{−1} collected by the CMS experiment at the LHC. The analysis targets Lorentz-boosted HH pairs identified using a graph neural network. It constrains the strengths relative to the standard model of the HH self-coupling and the quartic VVHH couplings, Îș2VÎș_{2V}, excluding Îș2V=0Îș_{2V} = 0 for the first time, with a significance of 6.3 standard deviations when other H couplings are fixed to their standard model values.A search for nonresonant Higgs boson (H) pair production via gluon and vector boson (V) fusion is performed in the four-bottom-quark final state, using proton-proton collision data at 13 TeV corresponding to 138  fb-1 collected by the CMS experiment at the LHC. The analysis targets Lorentz-boosted H pairs identified using a graph neural network. It constrains the strengths relative to the standard model of the H self-coupling and the quartic VVHH couplings, Îș2V, excluding Îș2V=0 for the first time, with a significance of 6.3 standard deviations when other H couplings are fixed to their standard model values.A search for nonresonant Higgs boson (HH) pair production via gluon and vector boson (VV) fusion is performed in the four-bottom-quark final state, using proton-proton collision data at 13 TeV corresponding to 138 fb−1^{−1} collected by the CMS experiment at the LHC. The analysis targets Lorentz-boosted HH pairs identified using a graph neural network. It constrains the strengths relative to the standard model of the HH self-coupling and the quartic VVHH couplings, Îș2VÎș_{2V}, excluding Îș2V=0Îș_{2V} = 0 for the first time, with a significance of 6.3 standard deviations when other H couplings are fixed to their standard model values.A search for nonresonant Higgs boson (H) pair production via gluon and vector boson (V) fusion is performed in the four-bottom-quark final state, using proton-proton collision data at 13 TeV corresponding to 138  fb-1 collected by the CMS experiment at the LHC. The analysis targets Lorentz-boosted H pairs identified using a graph neural network. It constrains the strengths relative to the standard model of the H self-coupling and the quartic VVHH couplings, Îș2V, excluding Îș2V=0 for the first time, with a significance of 6.3 standard deviations when other H couplings are fixed to their standard model values.A search for nonresonant Higgs boson (HH) pair production via gluon and vector boson (VV) fusion is performed in the four-bottom-quark final state, using proton-proton collision data at 13 TeV corresponding to 138 fb−1^{−1} collected by the CMS experiment at the LHC. The analysis targets Lorentz-boosted HH pairs identified using a graph neural network. It constrains the strengths relative to the standard model of the HH self-coupling and the quartic VVHH couplings, Îș2VÎș_{2V}, excluding Îș2V=0Îș_{2V} = 0 for the first time, with a significance of 6.3 standard deviations when other H couplings are fixed to their standard model values.A search for nonresonant Higgs boson (H) pair production via gluon and vector boson (V) fusion is performed in the four-bottom-quark final state, using proton-proton collision data at 13 TeV corresponding to 138  fb-1 collected by the CMS experiment at the LHC. The analysis targets Lorentz-boosted H pairs identified using a graph neural network. It constrains the strengths relative to the standard model of the H self-coupling and the quartic VVHH couplings, Îș2V, excluding Îș2V=0 for the first time, with a significance of 6.3 standard deviations when other H couplings are fixed to their standard model values.A search for nonresonant Higgs boson (H) pair production via gluon and vector boson (V) fusion is performed in the four-bottom-quark final state, using proton-proton collision data at 13 TeV corresponding to 138 fb−1^{-1} collected by the CMS experiment at the LHC. The analysis targets Lorentz-boosted H pairs identified using a graph neural network. It constrains the strengths relative to the standard model of the H self-coupling and the quartic VVHH couplings, Îș2V\kappa_{2V}, excluding Îș2V\kappa_{2V} = 0 for the first time, with a significance of 6.3 standard deviations when other H couplings are fixed to their standard model values

    Probing heavy Majorana neutrinos and the Weinberg operator through vector boson fusion processes in proton-proton collisions at s=\sqrt{s} = 13 TeV

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    The first search exploiting the vector boson fusion process to probe heavy Majorana neutrinos and the Weinberg operator at the LHC is presented. The search is performed in the same-sign dimuon final state using a proton-proton collision data set recorded at s=\sqrt{s} = 13 TeV, collected with the CMS detector and corresponding to a total integrated luminosity of 138 fb−1^{-1}. The results are found to agree with the predictions of the standard model. For heavy Majorana neutrinos, constraints on the squared mixing element between the muon and the heavy neutrino are derived in the heavy neutrino mass range 50 GeV-25 TeV; for masses above 650 GeV these are the most stringent constraints from searches at the LHC to date. A first test of the Weinberg operator at colliders provides an observed upper limit at 95% confidence level on the effective ΌΌ\mu\mu Majorana neutrino mass of 10.8 GeV.The first search exploiting the vector boson fusion process to probe heavy Majorana neutrinos and the Weinberg operator at the LHC is presented. The search is performed in the same-sign dimuon final state using a proton-proton collision dataset recorded at s=13  TeV, collected with the CMS detector and corresponding to a total integrated luminosity of 138  fb−1. The results are found to agree with the predictions of the standard model. For heavy Majorana neutrinos, constraints on the squared mixing element between the muon and the heavy neutrino are derived in the heavy neutrino mass range 50 GeV–25 TeV; for masses above 650 GeV these are the most stringent constraints from searches at the LHC to date. A first test of the Weinberg operator at colliders provides an observed upper limit at 95% confidence level on the effective ΌΌ Majorana neutrino mass of 10.8 GeV.The first search exploiting the vector boson fusion process to probe heavy Majorana neutrinos and the Weinberg operator at the LHC is presented. The search is performed in the same-sign dimuon final state using a proton-proton collision data set recorded at s\sqrt{s} = 13 TeV, collected with the CMS detector and corresponding to a total integrated luminosity of 138 fb−1^{-1}. The results are found to agree with the predictions of the standard model. For heavy Majorana neutrinos, constraints on the squared mixing element between the muon and the heavy neutrino are derived in the heavy neutrino mass range 50 GeV-25 TeV; for masses above 650 GeV these are the most stringent constraints from searches at the LHC to date. A first test of the Weinberg operator at colliders provides an observed upper limit at 95% confidence level on the effective ΌΌ\mu\mu Majorana neutrino mass of 10.8 GeV

    Measurement of the electroweak production of WÎł\gamma in association with two jets in proton-proton collisions at s\sqrt{s} = 13 TeV

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    A measurement is presented for the electroweak production of a W boson, a photon (Îł \gamma ), and two jets (j) in proton-proton collisions. The leptonic decay of the W boson is selected by requiring one identified electron or muon and large missing transverse momentum. The two jets are required to have large invariant dijet mass and large separation in pseudorapidity. The measurement is performed with the data collected by the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb−1 ^{-1} . The cross section for the electroweak WÎł \gamma jj production is 23.5 −4.7+4.9 ^{+4.9}_{-4.7} fb, whereas the total cross section for WÎł \gamma jj production is 113 ± \pm 13 fb. Differential cross sections are also measured with the distributions unfolded to the particle level. All results are in agreement with the standard model expectations. Constraints are placed on anomalous quartic gauge couplings (aQGCs) in terms of dimension-8 effective field theory operators. These are the most stringent limits to date on the aQGCs parameters fM,2−5/Λ4f_{\mathrm{M},2{-}5}/\Lambda^4 and fT,6−7/Λ4f_{\mathrm{T},6{-}7}/\Lambda^4.A measurement is presented for the electroweak production of a W boson, a photon (Îł), and two jets (j) in proton-proton collisions. The leptonic decay of the W boson is selected by requiring one identified electron or muon and large missing transverse momentum. The two jets are required to have large invariant dijet mass and large separation in pseudorapidity. The measurement is performed with the data collected by the CMS detector at a center-of-mass energy of 13  TeV, corresponding to an integrated luminosity of 138  fb-1. The cross section for the electroweak WÎłjj production is 23.5-4.7+4.9  fb, whereas the total cross section for WÎłjj production is 113±13  fb. Differential cross sections are also measured with the distributions unfolded to the particle level. All results are in agreement with the standard model expectations. Constraints are placed on anomalous quartic gauge couplings (aQGCs) in terms of dimension-8 effective field theory operators. These are the most stringent limits to date on the aQGCs parameters fM,2–5/Λ4 and fT,6–7/Λ4.A measurement is presented for the electroweak production of a W boson, a photon (Îł\gamma), and two jets (j) in proton-proton collisions. The leptonic decay of the W boson is selected by requiring one identified electron or muon and large missing transverse momentum. The two jets are required to have large invariant dijet mass and large separation in pseudorapidity. The measurement is performed with the data collected by the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb−1^{-1}. The cross section for the electroweak WÎł\gammajj production is 23.5 −4.7+4.9^{+4.9}_{-4.7} fb, whereas the total cross section for WÎł\gammajj production is 113 ±\pm 13 fb. Differential cross sections are also measured with the distributions unfolded to the particle level. All results are in agreement with the standard model expectations. Constraints are placed on anomalous quartic gauge couplings (aQGCs) in terms of dimension-8 effective field theory operators. These are the most stringent limits to date on the aQGCs parameters fM,2−5f_\mathrm{M,2-5}//Λ4\Lambda^4 and fT,6−7f_\mathrm{T,6-7}//Λ4\Lambda^4
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