We extend the applicability of Newton's method for approximating a solution of a nonlinear operator equation in a Banach space setting using nondiscrete mathematical induction concept introduced by Potra and Pták. We obtain new sufficient convergence conditions for Newton's method using Lipschitz and center-Lipschitz conditions instead of only the Lipschitz condition used in F. A. Potra, V. Pták, Sharp error bounds for Newton's process, Numer. Math., 34 (1980), 63–72, and F. A. Potra, V. Pták, Nondiscrete Induction and Iterative Processes, Research Notes in Mathematics, 103. Pitman Advanced Publishing Program, Boston, 1984. Under the same computational cost as before, we provide: weaker sufficient convergence conditions; tighter error estimates on the distances involved and more precise information on the location of the solution. Numerical examples are also provided in this study.
In this paper we contrast linear parametric estimation with non-parametric non-linear neural estimation of the reversion speed a, in the context of the Vasicek model, which is routinely being used for deriving the term structure of the short rate. The sampling parameters of the short-rate, even its realization, were varied widely. Neural regression was employed in an attempt to identify a possibly non-linear relationship, and from that to extract a measure of instantaneous reversion speed (a local equivalent of reversion speed). Neural network models outperformed consistently the linear estimator in ternis of explained variability by more than 10%, indicating a degree of non-linearity in the underlying relationship.
We prove some extension theorems involving uniformly continuous maps of the universal Urysohn space. As an application, we prove reconstruction theorems for certain groups of autohomeomorphisms of this space and of its open subsets.
We present a categorical approach to the extension of probabilities, i.e. normed σ-additive measures. J. Novák showed that each bounded σ-additive measure on a ring of sets A is sequentially continuous and pointed out the topological aspects of the extension of such measures on A over the generated σ-ring σ(A): it is of a similar nature as the extension of bounded continuous functions on a completely regular topological space X over its Čech-Stone compactification βX (or as the extension of continuous functions on X over its Hewitt realcompactification υX). He developed a theory of sequential envelopes and (exploiting the Measure Extension Theorem) he proved that σ(A) is the sequential envelope of A with respect to the probabilities. However, the sequential continuity does not capture other properties (e.g. additivity) of probability measures. We show that in the category ID of D-posets of fuzzy sets (such D-posets generalize both fields of sets and bold algebras) probabilities are morphisms and the extension of probabilities on A over σ(A) is a completely categorical construction (an epireflection). We mention applications to the foundations of probability and formulate some open problems.
Two categories $\mathbb{Set}(\Omega )$ and $\mathbb{SetF}(\Omega )$ of fuzzy sets over an $MV$-algebra $\Omega $ are investigated. Full subcategories of these categories are introduced consisting of objects $(\mathop {{\mathrm sub}}(A,\delta )$, $\sigma )$, where $\mathop {{\mathrm sub}}(A,\delta )$ is a subset of all extensional subobjects of an object $(A,\delta )$. It is proved that all these subcategories are quasi-reflective subcategories in the corresponding categories.
It is shown that a ring $R$ is a $GM$-ring if and only if there exists a complete orthogonal set $\lbrace e_1,\cdots ,e_n\rbrace $ of idempotents such that all $e_iRe_i$ are $GM$-rings. We also investigate $GM$-rings for Morita contexts, module extensions and power series rings.
The main goal of this paper is to construct fuzzy connectives on algebraic completely distributive lattice(ACDL) by means of extending fuzzy connectives on the set of completely join-prime elements or on the set of completely meet-prime elements, and discuss some properties of the new fuzzy connectives. Firstly, we present the methods to construct t-norms, t-conorms, fuzzy negations valued on ACDL and discuss whether De Morgan triple will be kept. Then we put forward two ways to extend fuzzy implications and also make a study on the behaviors of R-implication and reciprocal implication. Finally, we construct two classes of infinitely ⋁-distributive uninorms and infinitely ⋀-distributive uninorms.
We study (non-abelian) extensions of a given hom-Lie algebra and provide a geometrical interpretation of extensions, in particular, we characterize an extension of a hom-Lie algebra g by another hom-Lie algebra h and discuss the case where h has no center. We also deal with the setting of covariant exterior derivatives, Chevalley derivative, Maurer-Cartan formula, curvature and the Bianchi identity for the possible extensions in differential geometry. Moreover, we find a cohomological obstruction to the existence of extensions of hom-Lie algebras, i.e., we show that in order to have an extendible hom-Lie algebra, there should exist a trivial member of the third cohomology., Abdoreza R. Armakan, Mohammed Reza Farhangdoost., and Seznam literatury