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showing 10 items of 1277 documents

Topologies on Partial O*-Algebras

2002

In this chapter, we introduce some basic locally convex topologies on partial O*-algebras and we establish general properties of these topologies. In Section 4.1, we compare the graph topologies induced by different O-families on the same domain (and the corresponding families of bounded subsets). In the case where the domain D M of an O-family M is a (quasi-) Frechet space, the structure of bounded subsets in D M can be described in a rather explicit way. Section 4.2 and Section 4.3 are devoted to the topologization of (partial) O*-algebras. Section 4.2 deals with locally convex topologies, the so-called uniform topologies τ u , τ u , τ * u and quasiuniform topologies τ qu , and Section 4.…

Physicssymbols.namesakePure mathematicsFréchet spaceBounded functionHilbert spacesymbolsTopological graph theoryDirect limitOperator normCauchy sequenceNormed vector space
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Mean-Field Game Modeling the Bandwagon Effect with Activation Costs

2015

This paper provides a mean-field game theoretic model of the bandwagon effect in social networks. This effect can be observed whenever individuals tend to align their own opinions to a mainstream opinion. The contribution is threefold. First, we describe the opinion propagation as a mean-field game with local interactions. Second, we establish mean-field equilibrium strategies in the case where the mainstream opinion is constant. Such strategies are shown to have a threshold structure. Third, we extend the use of threshold strategies to the case of time-varying mainstream opinion and study the evolution of the macroscopic system.

Physics::Physics and SocietyStatistics and Probability0209 industrial biotechnologyEconomics and Econometrics02 engineering and technologyMean-field gamesMean field gameActivation costs; Bandwagon effect; Games with infinitely many players; Mean-field games; Mode; Threshold policies;01 natural sciencesActivation costs010305 fluids & plasmasMicroeconomics020901 industrial engineering & automationOpinion dynamicsGames with infinitely many players; Bandwagon effect; Activation costs; Threshold policies; Mean-field games; ModeMean-field game0103 physical sciencesEconomicsThreshold policiesMainstreamBandwagon effectStructure (mathematical logic)Game theoreticApplied MathematicsMode (statistics)Computer Science::Social and Information NetworksComputer Graphics and Computer-Aided DesignComputer Science ApplicationsComputational MathematicsActivation costComputational Theory and MathematicsGames with infinitely many playersGames with infinitely many playerModeSettore MAT/09 - Ricerca OperativaConstant (mathematics)Threshold policieMathematical economicsBandwagon effectDynamic Games and Applications
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Electron Holography for Electric and Magnetic Field Measurements and Its Application for Nanophysics

2011

Abstract Texture constitutes one of the fundamental properties of objects besides color and shape. In several image analysis applications, it is often the only exploitable quality of objects. As such, it has been studied, described, segmented, synthesized, or in short, analyzed extensively. Among the plethora of texture description methods, mathematical morphology deserves special attention as it excels at the exploitation of spatial relationships among pixels, rendering it inherently suitable for texture description. In this chapter, we focus on morphological texture description methods for grey-scale and color images in an effort to spread the advantages of this framework in the context o…

Pixelbusiness.industryComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISIONRangingMathematical morphologyElectron holographyMagnetic fieldRendering (computer graphics)Computer visionArtificial intelligenceSmall particlesbusinessComputingMethodologies_COMPUTERGRAPHICSMathematics
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Influence of pixel size on quantification of airway wall thickness in computed tomography.

2009

Objectives: The purpose of this study was to determine the point where a further decrease in voxel size does not result in better automatic quantification of the bronchial wall thickness by using 2 different assessment techniques. Materials and Methods: The results from the commonly used full-width-at-half-maximum (FWHM) principle and a new technique (integral-based method [IBM]) were compared for thin-section multidetector computed tomography (MDCT) data sets from an airway phantom containing 10 different tubular airway phantoms and in a human subsegmental bronchus in vivo. Correlation with the actual wall thickness and comparison of the wall thicknesses assessed for different voxel sizes …

Pixelmedicine.diagnostic_testbusiness.industryPhantoms ImagingComputed tomographyField of viewBronchiBronchographycomputer.software_genreImaging phantomRadiographic Image EnhancementFull width at half maximumVoxelApproximation errorComputer GraphicsMedicineHumansRadiographic Image Interpretation Computer-AssistedRadiology Nuclear Medicine and imagingbusinessNuclear medicineTomography X-Ray ComputedImage resolutioncomputerSoftwareJournal of computer assisted tomography
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C3N4/reduced graphene oxide photocatalysts loaded with Ag or Ag/Pt for H2 evolution from aqueous solution of triethanolamine

2023

Composites of C3N4/reduced graphene oxide have been used as photocatalysts for triethanolamine photo- reforming with H2 generation in aqueous solution. The rate of H2 production over the Ag loaded best per- forming photocatalyst reached 525 μmol⋅h

Platinum cocatalystC3N4/reduced graphene oxidePhotoreformingGeneral ChemistrySilver cocatalystSettore CHIM/06 - Chimica OrganicaSettore CHIM/07 - Fondamenti Chimici Delle TecnologieH2 evolutionCatalysis
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Effect of air pressure on the electro-generation of H2O2 and the abatement of organic pollutants in water by electro-Fenton process

2015

Abstract The electro-generation of H 2 O 2 and the abatement of the model organic pollutant Acid Orange 7 (AO7) in water by an electro-Fenton process were performed under moderate air pressures (up to 11 bar) for the first time to our knowledge. An increase of the pressure gave rise to a drastic enhancement of the concentration of hydrogen peroxide. In systems pressurized with air at 11 bar, the electro reduction of oxygen at a graphite cathode gave rise to a concentration of H 2 O 2 of about 12 mM, about one order of magnitude higher than that achieved at atmospheric pressure. This result is attributed to the mass transfer intensification induced by the higher local concentration of molecu…

PollutantAtmospheric pressureChemistryGeneral Chemical EngineeringAqueous two-phase systemchemistry.chemical_elementCompact graphite.Wastewater treatmentHydrogen peroxideOxygenCathodelaw.inventionAir pressurechemistry.chemical_compoundAcid orange 7Chemical engineeringlawMass transferEnvironmental chemistryElectrochemistryElectro-FentonGraphiteHydrogen peroxideAOP
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Torsional effects on the molecular polarizabilities of the benzothiazole (A)-benzobisthiazole (B) oligomer A-B13-A

1996

Abstract We outline a method for the calculation of multipole moments and molecular dipole-dipole ( ), dipole-quadrupole ( ), and quadrupole-quadrupole ( ) polarizabilities, which we have successfully applied to benzothiazole (A)-benzobisthiazole (B) oligomer A-B13-A. Three model rotational isomers have been characterized: (1) the fully planar (000) rotational isomer; (2) a conformation with each unit rotated 10° in the alternate direction (+−+), and (3) a rotational isomer with each unit rotated 10° in the same direction (+++). The dipole moment, μ , is smaller for isomers 000 and +−+ than for isomer +++. The calculation of , , and has been performed by use of the interacting induced dipol…

PolymersChemistryStatic ElectricityMolecular ConformationBiophysicsBiochemistryOligomerThiazolesCrystallographychemistry.chemical_compoundDipoleModels ChemicalSolubilityBenzothiazoleComputational chemistryComputer GraphicsPhysics::Atomic and Molecular ClustersPolarComputer SimulationBenzothiazolesPhysics::Chemical PhysicsSolubilityAnisotropyMultipole expansionOrder of magnitudeJournal of Molecular Graphics
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Novel algorithms for 3D surface point cloud boundary detection and edge reconstruction

2019

Abstract Tessellated surfaces generated from point clouds typically show inaccurate and jagged boundaries. This can lead to tolerance errors and problems such as machine judder if the model is used for ongoing manufacturing applications. This paper introduces a novel boundary point detection algorithm and spatial FFT-based filtering approach, which together allow for direct generation of low noise tessellated surfaces from point cloud data, which are not based on pre-defined threshold values. Existing detection techniques are optimized to detect points belonging to sharp edges and creases. The new algorithm is targeted at the detection of boundary points and it is able to do this better tha…

PolynomialBoundary detection Edge reconstruction Point-cloudComputer scienceTKFast Fourier transformComputational MechanicsPoint cloudBoundary (topology)02 engineering and technologySettore ING-IND/14 - Progettazione Meccanica E Costruzione Di Macchine0203 mechanical engineeringlcsh:TA1740202 electrical engineering electronic engineering information engineeringEngineering (miscellaneous)Function (mathematics)lcsh:Engineering designComputer Graphics and Computer-Aided DesignHuman-Computer InteractionComputational MathematicsNoise020303 mechanical engineering & transportsModeling and SimulationCurve fittingArtificial noise020201 artificial intelligence & image processingAlgorithmJournal of Computational Design and Engineering
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Symbolic Worst Case Execution Times

2011

In immediate or hard real-time systems the correctness of an operation depends not only upon its logical correctness, but also on the time in which it is computed. In such systems, it is imperative that operations are performed within a given deadline because missing this deadline constitutes the failure of the complete system. Such systems include medical systems, flight control systems and other systems whose failure in responding punctually results in a high economical loss or even in the loss of human lives. These systems are usually analyzed in a sequence of steps in which first, a socalled control flow graph (CFG) is constructed that represents possible program flows. Furthermore, bou…

PolynomialSequenceCorrectnessWorst-case execution timeComputer scienceCode (cryptography)Control flow graphInteger programmingAlgorithmLongest path problem
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Wavelet Frames Generated by Perfect Reconstruction Filter Banks

2015

It was indicated in Sect. 2.2 that oversampled perfect reconstruction (PR) filter banks generate specific types of frames in the signal space. In this chapter, a family of tight and semi-tight frames is presented. The three- and four-channel filter banks that generate the framed originate from polynomial and discrete splines. Those frames have properties, which are attractive for signal processing, such as symmetry, interpolation, flat spectra. These properties are combined with fine time-domain localization and efficient implementation. This family includes framelets, that have any number of discrete vanishing moments. Non-compactness of their supports is compensated by exponential decay o…

PolynomialSignal processingWaveletComputer scienceInterpolation (computer graphics)Filter (signal processing)Symmetry (geometry)Filter bankSignalAlgorithm
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