Search results for " function"

showing 10 items of 9395 documents

Development and changes in the industrial function of a city with reference to the conception of sustainable development (a study case of Opole)

2015

The principal goal of the paper is to identify the influence of the industrial sphere on the development of and changes in a city, according to rules of sustainable development. The first part of the article is devoted to industrial objects and area which have existed for about 20 years and are characterized by huge changes. It is important to answer the questions: how changes in the case of an obsolete industrial area are related to social and environmental spheres, and what should be done in the case of a negative influence of the industrial sphere on the other two. Furthermore, it is important to identify the performance and actions which are taken by the local government in this context…

sustainable developmenturban policycity developmentindustrial functionStudia Regionalia/ Polish Academy of Sciences. Committee for Space Economy and Regional Planning.
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Representing compact sets of compact operators and of compact range vector measures

1987

symbols.namesakeApproximation propertyNuclear operatorGeneral MathematicsHilbert spacesymbolsFinite-rank operatorCompact operatorTopologyInvariant subspace problemContinuous functions on a compact Hausdorff spaceCompact operator on Hilbert spaceMathematicsArchiv der Mathematik
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Stationary and Nontationary Response Probability Density Function of a Beam under Poisson White Noise

2011

In this paper an approximate explicit probability density function for the analysis of external oscillations of a linear and geometric nonlinear simply supported beam driven by random pulses is proposed. The adopted impulsive loading model is the Poisson White Noise , that is a process having Dirac’s delta occurrences with random intensity distributed in time according to Poisson’s law. The response probability density function can be obtained solving the related Kolmogorov-Feller (KF) integro-differential equation. An approximated solution, using path integral method, is derived transforming the KF equation to a first order partial differential equation. The method of characteristic is the…

symbols.namesakeCharacteristic function (probability theory)Cumulative distribution functionMathematical analysissymbolsFirst-order partial differential equationProbability distributionProbability density functionWhite noiseMoment-generating functionPoisson distributionMathematics
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On the spectrum of semi-classical Witten-Laplacians and Schrödinger operators in large dimension

2005

We investigate the low-lying spectrum of Witten–Laplacians on forms of arbitrary degree in the semi-classical limit and uniformly in the space dimension. We show that under suitable assumptions implying that the phase function has a unique local minimum one obtains a number of clusters of discrete eigenvalues at the bottom of the spectrum. Moreover, we are able to count the number of eigenvalues in each cluster. We apply our results to certain sequences of Schrodinger operators having strictly convex potentials and show that some well-known results of semi-classical analysis hold also uniformly in the dimension.

symbols.namesakeDimension (vector space)Degree (graph theory)Mathematical analysisSpectrum (functional analysis)Thermodynamic limitsymbolsLimit (mathematics)Convex functionAnalysisEigenvalues and eigenvectorsSchrödinger's catMathematicsJournal of Functional Analysis
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Poincare Inequalities and Spectral Gap, Concentration Phenomenon for G-Measures

2002

We produce a new approach based upon inequalities of Poincare’s type for giving constructive estimates of the mixing rate for a family of mixing stationary processes continuously depending on their past called g-measures. We establish also exponential inequalities of Hoeffding’s type leading to a concentration phenomenon for a large class of observables; this last property permits in particular to give the typical behaviour of the n-orbits of a g-measure.

symbols.namesakeDirichlet formMathematical analysissymbolsSpectral gapProduct topologyGibbs measureType (model theory)ConstructiveMixing (physics)MathematicsExponential function
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Saddle index properties, singular topology, and its relation to thermodynamic singularities for aϕ4mean-field model

2004

We investigate the potential energy surface of a ${\ensuremath{\phi}}^{4}$ model with infinite range interactions. All stationary points can be uniquely characterized by three real numbers ${\ensuremath{\alpha}}_{+},{\ensuremath{\alpha}}_{0},{\ensuremath{\alpha}}_{\ensuremath{-}}$ with ${\ensuremath{\alpha}}_{+}+{\ensuremath{\alpha}}_{0}+{\ensuremath{\alpha}}_{\ensuremath{-}}=1$, provided that the interaction strength $\ensuremath{\mu}$ is smaller than a critical value. The saddle index ${n}_{s}$ is equal to ${\ensuremath{\alpha}}_{0}$ and its distribution function has a maximum at ${n}_{s}^{\mathrm{max}}=1∕3$. The density $p(e)$ of stationary points with energy per particle $e$, as well as…

symbols.namesakeDistribution functionMean field theoryEuler characteristicPotential energy surfaceZero (complex analysis)symbolsGround stateTopologyEnergy (signal processing)Real numberMathematicsPhysical Review E
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Special Functions for the Study of Economic Dynamics: The Case of the Lucas-Uzawa Model

2004

The special functions are intensively used in mathematical physics to solve differential systems. We argue that they should be most useful in economic dynamics, notably in the assessment of the transition dynamics of endogenous growth models. We illustrate our argument on the Lucas-Uzawa model, which we solve by the means of Gaussian hypergeometric functions. We show how the use of Gaussian hypergeometric functions allows for an explicit representation of the equilibrium dynamics of the variables in level. In contrast to the preexisting approaches, our method is global and does not rely on dimension reduction.

symbols.namesakeEndogenous growth theorySpecial functionsDimensionality reductionGaussiansymbolsContrast (statistics)Hypergeometric functionOptimal controlRepresentation (mathematics)Mathematical economicsMathematicsSSRN Electronic Journal
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Excitation energies and photoabsorption oscillator strengths of the Rydberg series in CF3Cl. A linear response and quantum defect study.

2007

Vertical excitation energies of the CF(3)Cl molecule have been obtained from a response function approach with a CC reference function to determine absolute photoabsorption oscillator strengths in the molecular-adapted quantum defect orbital formalism (MQDO). The present work covers more highly excited Rydberg states than have been experimentally reported. Assessing of the reliability of the present calculations is provided through a comparative analysis between the results of the molecule and the Cl atom. This can be used to allow for predictions of the same type of properties in other analogous systems.

symbols.namesakeFormalism (philosophy of mathematics)Quantum defectChemistryExcited stateRydberg formulasymbolsMoleculePhysical and Theoretical ChemistryReference functionAtomic physicsExcitationThe journal of physical chemistry. A
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A Stieltjes Approach to Static Hedges

2014

Static hedging of complicated payoff structures by standard instruments becomes increasingly popular in finance. The classical approach is developed for quite regular functions, while for less regular cases, generalized functions and approximation arguments are used. In this note, we discuss the regularity conditions in the classical decomposition formula due to P. Carr and D. Madan (in Jarrow ed, Volatility, pp. 417–427, Risk Publ., London, 1998) if the integrals in this formula are interpreted as Lebesgue integrals with respect to the Lebesgue measure. Furthermore, we show that if we replace these integrals by Lebesgue–Stieltjes integrals, the family of representable functions can be exte…

symbols.namesakeGeneralized functionLebesgue measureDirect methodMathematical analysisBounded variationStochastic gamesymbolsApplied mathematicsRiemann–Stieltjes integralAbsolute continuityLebesgue integrationMathematics
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Constant inner potential DFT for modelling electrochemical systems under constant potential and bias

2021

Electrochemical interfaces and reactions play a decisive role in e.g. clean energy conversion but understanding their complex chemistry remains an outstanding challenge. Constant potential or grand canonical ensemble (GCE) simulations are indispensable for unraveling the properties of electrochemical processes as a function of the electrode potential. Currently, constant electrode potential calculations at the density functional theory (DFT) level are carried out by fixing the Fermi level of the simulation cell. However, the Fermi level from DFT calculations does does not always reflect the experimentally controlled electrode potential or describe the thermodynamic independent variable in G…

symbols.namesakeGrand canonical ensembleMaterials scienceChemical physicsFermi levelsymbolsDensity functional theoryConstant (mathematics)ElectrocatalystForce field (chemistry)Electrode potentialElectrochemical potential
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