Search results for "Set theory"
showing 10 items of 751 documents
Stereoselective Syntheses of Naturally Occurring 5,6-Dihydropyran-2-ones
2007
The published syntheses of naturally occurring 5,6-dihydropyran-2-ones are reviewed. Figure options Download full-size image Download as PowerPoint slide
Generalized John disks
2014
Abstract We establish the basic properties of the class of generalized simply connected John domains.
A Mountain Pass Theorem for a Suitable Class of Functions
2009
Existence of viscosity solutions to two-phase problems for fully nonlinear equations with distributed sources
2018
In this paper we construct a viscosity solution of a two-phase free boundary problem for a class of fully nonlinear equation with distributed sources, via an adaptation of the Perron method. Our results extend those in [Caffarelli, 1988], [Wang, 2003] for the homogeneous case, and of [De Silva, Ferrari, Salsa, 2015] for divergence form operators with right hand side.
Semmes surfaces and intrinsic Lipschitz graphs in the Heisenberg group
2018
A Semmes surface in the Heisenberg group is a closed set $S$ that is upper Ahlfors-regular with codimension one and satisfies the following condition, referred to as Condition B. Every ball $B(x,r)$ with $x \in S$ and $0 < r < \operatorname{diam} S$ contains two balls with radii comparable to $r$ which are contained in different connected components of the complement of $S$. Analogous sets in Euclidean spaces were introduced by Semmes in the late $80$'s. We prove that Semmes surfaces in the Heisenberg group are lower Ahlfors-regular with codimension one and have big pieces of intrinsic Lipschitz graphs. In particular, our result applies to the boundary of chord-arc domains and of redu…
Corrigendum to “Imaginary time propagation code for large-scale two-dimensional eigenvalue problems in magnetic fields” [Comput. Phys. Comm. 184(3) (…
2016
Evaluation of legendre functions of argument greater than one
1997
Abstract In this paper we present an algorithm to evaluate Legendre functions of the first and second kinds ( P v , Q v ) for integraland half-integral order and argument greater than one. The code is based on the calculation of the continued fraction for the Q 's. the Wronskian relating P 's and Q 's and the application of forward recurrence relations for the P 's and backward recurrence for the Q 's. We also show an application of these algorithms to the evaluation of the electrostatic field due to a charged toroidal conductor at potential V .
Panel Summary Perceptual Learning and Discovering
1994
The problem of learning and discovering in perception is addressed and discussed with particular reference to present machine learning paradigms. These paradigms are briefly introduced by S. Gaglio. The subsymbolic approach is addressed by S. Nolfi, and the role of symbolic learning is analysed by F. Esposito. Many of the open problems, that are evidentiated in the course of the panel, show how this is an important field of research that still needs a lot of investigation. In particular, as a result of the whole discussion, it seems that a suitable integration of different approaches must be accurately investigated. It is observed, in fact, that the weakness of the most part of the existing…
Fittingmengen und lockettabschnitte
1990
Abstract The theory of Lockett sections is transferred from Fitting classes to Fitting sets. This in general works only partially; in some special groups (which I call “mobility” groups), however, among these the stable linear groups, a literal translation of the Fitting class theory is possible. As the groups relevant in outer Fitting pairs actually are mobility groups, a new way of deriving information on the Lockett section of a Fitting class arises. This is used to present a simplified, if nonsoluble, counter-example to Lockett's conjecture and to decide a related question. Also, an approach to generating Fitting classes is given.