Search results for "basis"

showing 10 items of 760 documents

Critical analysis of the spin-rotation constants of CF2 and CCl2: A theoretical investigation

2005

Quantum chemical ab initio calculations for the spin-rotation constants of difluorocarbene (CF2) and dichlorocarbene (CCl2) were carried out using coupled-cluster techniques with sequences of correlation-consistent basis sets. Theoretical best estimates were obtained using extrapolation to the complete basis-set limit and taking into account corrections for core correlation, additional diffuse functions and zero-point vibrational effects. It is demonstrated that such accurate theoretical estimates can be used either to support or to challenge the analysis of the experimental spectra and the reliability of the resulting data. 2005 Elsevier B.V. All rights reserved.

DifluorocarbeneBasis (linear algebra)ExtrapolationGeneral Physics and AstronomySpectral lineComputational physicschemistry.chemical_compoundchemistryAb initio quantum chemistry methodsLimit (mathematics)Physical and Theoretical ChemistryAtomic physicsRotation (mathematics)Spin-½Chemical Physics Letters
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Implementation of pattern recognition algorithm based on RBF neural network

2002

In this paper, we present implementations of a pattern recognition algorithm which uses a RBF (Radial Basis Function) neural network. Our aim is to elaborate a quite efficient system which realizes real time faces tracking and identity verification in natural video sequences. Hardware implementations have been realized on an embedded system developed by our laboratory. This system is based on a DSP (Digital Signal Processor) TMS320C6x. The optimization of implementations allow us to obtain a processing speed of 4.8 images (240x320 pixels) per second with a correct rate of 95% of faces tracking and identity verification.

Digital signal processorArtificial neural networkPixelComputer sciencebusiness.industryPattern recognitionPattern recognition (psychology)Identity (object-oriented programming)Radial basis functionComputer visionArtificial intelligencebusinessAlgorithmImplementationDigital signal processingSPIE Proceedings
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New Theoretical Solution of Stage-Discharge Relationship for Slit Weirs

2018

In this paper, the flow-process of a slit weir was analyzed on the basis of a theorem of dimensional analysis and incomplete selfsimilarity theory. The theoretically deduced stage-discharge formula then was calibrated using experimental data obtained for a ratio between the weir and the channel width, ranging from 0.05 to 0.25. The deduced stage-discharge relationship allowed measuring discharge values characterized by errors that, for 98% of the measured values, were less than or equal to 5%. The performance of the proposed theoreticalstage-discharge formula also was improved by introducing the Reynolds number (for 98.5% of the measured values the error was less than or equal to 5%, and th…

Dimensional analysiSelf-similarityBasis (linear algebra)0208 environmental biotechnologyDischarge measurements02 engineering and technologyMechanics01 natural sciencesAgricultural and Biological Sciences (miscellaneous)SlitOpen channel flow010305 fluids & plasmas020801 environmental engineeringOpen-channel flowSelf-similarity0103 physical sciencesWeirSettore AGR/08 - Idraulica Agraria E Sistemazioni Idraulico-ForestaliStage (hydrology)Discharge measurementWeirWater Science and TechnologyCivil and Structural EngineeringMathematicsJournal of Irrigation and Drainage Engineering
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A Note on Riesz Bases of Eigenvectors of Certain Holomorphic Operator-Functions

2001

Abstract Operator-valued functions of the form A (λ) ≔ A − λ + Q(λ) with λ ↦ Q(λ)(A − μ)− 1 compact-valued and holomorphic on certain domains Ω ⊂  C are considered in separable Hilbert space. Assuming that the resolvent of A is compact, its eigenvalues are simple and the corresponding eigenvectors form a Riesz basis for H of finite defect, it is shown that under certain growth conditions on ‖Q(λ)(A − λ)− 1‖ the eigenvectors of A corresponding to a part of its spectrum also form a Riesz basis of finite defect. Applications are given to operator-valued functions of the form A (λ) = A − λ + B(λ − D)− 1C and to spectral problems in L2(0, 1) of the form −f″(x) + p(x, λ)f′(x) + q(x, λ)f(x) = λf(x…

Dirichlet problemPure mathematicsApplied MathematicsMathematical analysisHolomorphic functionHilbert spaceeigenvectorsoperator-functionRiesz basisSeparable spacesymbols.namesakeDirichlet boundary conditionsymbolsCauchy's integral theoremAnalysisEigenvalues and eigenvectorsMathematicsResolventJournal of Mathematical Analysis and Applications
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Aggregation of Risk Level Assessments Based on Fuzzy Equivalence Relation

2017

The paper deals with the problem of aggregation of risk level assessments. We describe the technique of a risk level evaluation taking into account values of the risk level obtained for objects which are in some sense equivalent. For this purpose we propose to use the construction of a general aggregation operator based on the corresponding fuzzy equivalence relation. Numerical example of the investment risk level aggregation using an equivalence relation obtained on the basis of different macroeconomic factors for countries of one region is considered.

Discrete mathematics0209 industrial biotechnologyMathematical optimizationRisk levelBasis (linear algebra)Financial risk02 engineering and technologyFuzzy equivalence relation020901 industrial engineering & automationOperator (computer programming)0202 electrical engineering electronic engineering information engineeringEquivalence relation020201 artificial intelligence & image processingMathematics
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On a linear diophantine problem of Frobenius

1993

Abstract In this paper, linear diophantine problem of Frobenius is discussed. A theorem concerning the largest integer g m (a1,a2) and the smallest integer G m (a1,a2) with m different representations with a1,a2 as basis is proved.

Discrete mathematicsBasis (linear algebra)Diophantine equationElectrical and Electronic EngineeringSafety Risk Reliability and QualityCondensed Matter PhysicsAtomic and Molecular Physics and OpticsSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsInteger (computer science)MathematicsMicroelectronics Reliability
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Thin bases of order h

2003

Abstract A subset A⊆ N 0 is called a basis of order h if every positive integer can be represented as a sum of h members of A . Thin bases of order h will be constructed in this paper, for each h ⩾2, where the value of lim sup A(n)/ n h is smaller than that of thin bases known so far. In the most important case h =2 it is shown that for the considered class of bases (which generalizes an ansatz of Stohr) the result is best possible up to an e >0.

Discrete mathematicsCombinatoricsClass (set theory)Algebra and Number TheoryIntegerOrder (group theory)Value (computer science)Basis (universal algebra)MathematicsAnsatzJournal of Number Theory
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Basis-set completeness profiles in two dimensions

2002

A two-electron basis-set completeness profile is proposed by analogy with the one-electron profile introduced by D. P. Chong (Can J Chem 1995, 73, 79). It is defined as Y(alpha, beta) = sigmam sigman (Galpha(1)Gbeta(2)/(1/r12)/ psim(1)psin(2)) (psim(1)psin(2)/r12/Galpha(1)Gp(2)) and motivated by the expression for the basis-set truncation correction that occurs in the framework of explicitly correlated methods (Galpha is a scanning Gaussian-type orbital of exponent alpha and [psim] is the orthonormalized one-electron basis under study). The two-electron basis-set profiles provide a visual assessment of the suitability of basis sets to describe electron-correlation effects. Furthermore, they…

Discrete mathematicsComputational MathematicsAngular momentumBasis (linear algebra)TruncationCompleteness (order theory)ExponentGeneral ChemistryExpression (computer science)Linear subspaceBasis setMathematicsJournal of Computational Chemistry
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The Alternating BWT: an algorithmic perspective

2020

Abstract The Burrows-Wheeler Transform (BWT) is a word transformation introduced in 1994 for Data Compression. It has become a fundamental tool for designing self-indexing data structures, with important applications in several areas in science and engineering. The Alternating Burrows-Wheeler Transform (ABWT) is another transformation recently introduced in Gessel et al. (2012) [21] and studied in the field of Combinatorics on Words. It is analogous to the BWT, except that it uses an alternating lexicographical order instead of the usual one. Building on results in Giancarlo et al. (2018) [23] , where we have shown that BWT and ABWT are part of a larger class of reversible transformations, …

Discrete mathematicsFOS: Computer and information sciencesSettore INF/01 - InformaticaGeneral Computer ScienceBasis (linear algebra)Computer scienceAlternating Burrows-Wheeler TransformGalois wordRank-invertibilityField (mathematics)Data structureTheoretical Computer ScienceTransformation (function)Difference cover algorithmComputer Science - Data Structures and AlgorithmsData Structures and Algorithms (cs.DS)Time complexityAlternating Burrows-Wheeler Transform; Difference cover algorithm; Galois word; Rank-invertibilityWord (computer architecture)Data compression
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Constructive proofs of representation theorems in separable Hilbert space

1964

Discrete mathematicsHilbert's second problemPure mathematicsHilbert manifoldRiesz representation theoremApplied MathematicsGeneral MathematicsRigged Hilbert spaceCylinder set measureHilbert's basis theoremConstructivesymbols.namesakesymbolsKuiper's theoremMathematicsCommunications on Pure and Applied Mathematics
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