Results 251 to 260 of about 6,651,187 (298)

Automated Fitting of Nonstandard Models

Multivariate Behavioral Research, 1992
A method for automated parameter estimation and testing of fit of nonstandard models for mean vectors and covariance matrices is described. Nonlinear equality and inequality constraints on the parameters of the model are allowed for. All the user will need to provide are subroutines to evaluate the mean vector and covariance matrix according to the ...
Michael W Browne
exaly   +3 more sources

Numbers and models, standard and nonstandard

Mathematische Semesterberichte, 2010
The author speaks about his personal recollections of Abraham Robinson, mainly concerning nonstandard analysis and also nonstandard algebra as well as nonstandard arithmetic.
exaly   +2 more sources

Nonstandard Models

2007
Martin Vath
exaly   +3 more sources

Exact and nonstandard numerical schemes for linear delay differential models

Applied Mathematics and Computation, 2018
Delay differential models present characteristic dynamical properties that should ideally be preserved when computing numerical approximate solutions. In this work, exact numerical schemes for a general linear delay differential model, as well as for the
Francisco Rodríguez, J A Martin
exaly   +2 more sources

Modeling vagueness by nonstandardness

Fuzzy Sets and Systems, 1998
The paper is a philosophical discussion of some possibilities to model vagueness in mathematics. For this goal, the author takes into consideration nonstandardness and demonstrates that some properties of typically vague predicates (such as ``small'') can be modelled in nonstandard models of arithmetics. The standard numbers represent ``horizon'', i.e.
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Positive and elementary stable nonstandard numerical methods with applications to predator–prey models [PDF]

Journal of Computational and Applied Mathematics, 2006
Positive and elementary stable nonstandard (PESN) finite-difference methods, having the same qualitative features as the corresponding continuous predator–prey models, are formulated and analyzed. The proposed numerical techniques are based on a nonlocal
Hristo Kojouharov
exaly   +2 more sources

Nonstandard models that are definable in models of Peano Arithmetic

Mathematical Logic Quarterly, 2007
AbstractIn this paper, we investigate definable models of Peano Arithmetic PA in a model of PA. For any definable model N without parameters in a model M, we show that N is isomorphic to M if M is elementary extension of the standard model and N is elementarily equivalent to M.
Kazuma Ikeda, Akito Tsuboi
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Nonstandard natural number systems and nonstandard models

Journal of Symbolic Logic, 1981
AbstractIt is known (see [1, 3.1.5]) that the order type of the nonstandard natural number system *N has the form ω + (ω* + ω) θ, where θ is a dense order type without first or last element and ω is the order type of N. Concerning this, Zakon [2] examined *N more closely and investigated the nonstandard real number system *R, as an ordered set, as an ...
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A nonstandard model

Foundations of Physics, 1993
An elementary-particle picture developed primarily by Barut as an alternative to the standard model is re-examined. This model is formulated on the basis of strong short-range magnetic interactions among the stable particles (p, e−, v) and at present is able to account qualitatively for most of the known phenomena.
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Construction of Satisfaction Classes for Nonstandard Models

Canadian Mathematical Bulletin, 1981
AbstractGiven a resplendent model for Peano arithmetic there exists a full satisfaction class over , i.e. an assignment of truth-values, to all closed formulas in the sense of with parameters from , which satisfies the usual semantic rules. The construction is based on the consistency of an appropriate system of -logic which is proved by an analysis ...
Kotlarski, H., Krajewski, S., Lachlan, A. H.   +2 more
openaire   +1 more source