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Search for supersymmetry in pp collisions at sqrt(s) = 8 TeV in final states with boosted W bosons and b jets using razor variables
No full textA search for supersymmetry in hadronic final states with highly boosted W bosons and b jets is presented, focusing on compressed scenarios. The search is performed using proton-proton collision data at a center-of-mass energy of 8 TeV, collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 19.7 fb−1. Events containing candidates for hadronic decays of boosted W bosons are identified using jet substructure techniques, and are analyzed using the razor variables MR and R2, which characterize a possible signal as a peak on a smoothly falling background. The observed event yields in the signal regions are found to be consistent with the expected contributions from standard model processes, which are predicted using control samples in the data. The results are interpreted in terms of gluino-pair production followed by their exclusive decay into top squarks and top quarks. The analysis excludes gluino masses up to 1.1 TeV for light top squarks decaying solely to a charm quark and a neutralino, and up to 700 GeV for heavier top squarks decaying solely to a top quark and a neutralino.LPH
Assessment of Timing and Performance based on Trajectories from low-cost GPS/INS Positioning
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The origin of early age expansions induced in cementitious materials containing shrinkage reducing admixtures
No full textStudies on the early-age shrinkage behavior of cement pastes, mortars, and concretes containing shrinkage reducing admixtures (SRAs) have indicated these mixtures frequently exhibit an expansion shortly after setting. While the magnitude of the expansion has been noted to be a function of the chemistry of the cement and the admixture dosage: the cause of the expansion is not clearly understood. This investigation uses measurements of autogenous deformation, X-ray diffraction, pore solution analysis, thermogravimetry, and scanning electron microscopy to study the early-age properties and describe the mechanism of the expansion in OPC pastes made with and without SRA. The composition of the pore solution indicates that the presence of the SRA increases the portlandite oversaturation level in solution which can result in higher crystallization stresses which could lead to an expansion. This observation is supported by deformation calculations for the systems examined. (C) 2010 Elsevier Ltd. All rights reserved.LM
Tensile elongation of unidirectional or laminated composites combining a brittle reinforcement with a ductile strain and strain-rate hardening matrix
No full textWe use the long-wavelength model of Hutchinson and Neale (1977) and Ghosh (1977) to estimate the uniform tensile elongation of two-phase composites deforming quasistatically according to the equistrain rule of mixtures, in which one phase is ductile while the other fractures progressively according to two-parameter Weibull statistics. We use shear-lag models in the literature to quantify load transfer from the ductile phase to the fractured brittle phase, and to estimate the influence of matrix strain and strain-rate hardening, of brittle phase fracture characteristics, and of phase volume and strength ratios, on the composite strain to failure as dictated by the onset of unstable necking. Calculations show that strain and strain-rate hardening of the ductile phase do relatively little to increase the ductility of the composite. Two parameters play a dominant role, namely the brittle-phase Weibull modulus and a dimensionless parameter describing load transfer across the two phases. The main practical implication of this analysis is that, to produce reasonably ductile two-phase composites, the best strategy is to aim for small layer thicknesses. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.LM
Electronic transport across quantum dots in graphene nanoribbons: Toward built-in gap-tunable metal-semiconductor-metal heterojunctions
No full textThe success of all-graphene electronics is severely hindered by the challenging realization and subsequent integration of semiconducting channels and metallic contacts. Here, we comprehensively investigate the electronic transport across width-modulated heterojunctions consisting of a graphene quantum dot of varying lengths and widths embedded in a pair of armchair-edged metallic nanoribbons, of the kind recently fabricated via on-surface synthesis. We show that the presence of the quantum dot enables the opening of a width-dependent transport gap, thereby yielding built-in one-dimensional metal-semiconductor-metal junctions. Furthermore, we find that, in the vicinity of the band edges, the conductance is subject to a smooth transition from an antiresonant to a resonant transport regime upon increasing the channel length. These results are rationalized in terms of a competition between quantum-confinement effects and quantum dot-to-lead coupling. Overall, our work establishes graphene quantum dot nanoarchitectures as appealing platforms to seamlessly integrate gap-tunable semiconducting channels and metallic contacts into an individual nanoribbon, hence realizing self-contained carbon-based electronic devices.C3M
MATHICSE Technical Report : A continuation-multilevel Monte Carlo evolutionary algorithm for robust aerodynamic shape design
No full textThe majority of problems in aircraft production and operation require decisions made in the presence of uncertainty. For this reason aerodynamic designs obtained with traditional deterministic optimization techniques seeking only optimality in a specific set of conditions may have very poor off-design performances or may even be unreliable. In this work, we present a novel approach for robust and reliability-based design optimization of aerodynamic shapes based on the combination of single and multi-objective Evolutionary Algorithms and a Continuation Multi Level Monte Carlo methodology to compute objective functions and constraints that involve statistical moments or statistical quantities such as quantiles, also called Value at risk, (VaR) and Conditional Value at Risk (CVaR) without relying on derivatives and meta-models. Detailed numerical studies are presentedCSQIMATHICSE Technical Report Nr. 06.2018 April 201
System and method for transcoding spectral data with task-based optimization via symmetric non-negative matrix factorization
No full textA computer-implemented method for reconstructing/recovering high-resolution visible light spectral data at a target resolution d, that comprises obtaining a configuration of a low- resolution multi-channel imaging sensor of resolution p, the configuration being enabled to produce measurements results of any one of a plurality of n determined visible light spectra, the low-resolution multi-channel imaging sensor comprising a number p of optical sensors arranged at locations in the spectrometer corresponding each to an attributed measurable wavelength of the visible light, the configuration comprising a definition of the attributed measurable wavelength for each location. The method comprises obtaining a library L comprising a previously measured set of the plurality of n determined visible light spectra at a high-resolution resolution d, the resolution d being greater than the resolution p, constructing a vector of p channel peak wavelengths by determining the first p channels with the highest evenness to maximize encoded information. The method comprises obtaining a set of reference spectra from L by finding the first k cluster centers such that f(H,k) = min(||A- HH'||2) to be used to fit regularization parameters for unknown spectra via Tikhonov regularization and adaptive dictionary learning.AVP-R-TTOLIPIDAlternative title(s) : (de) System und verfahren zur transcodierung von spektraldaten mit aufgabenbasierter optimierung mittels symmetrischer nichtnegativer matrixfaktorisierung (fr) Système et procédé de transcodage de données spectrales avec optimisation à base de tâches via une factorisation de matrice symétrique non négativ
