1,201 research outputs found
Un model geometric al legaturilor directe dintre fenomenele economice
Abstract. In this paper we approach the issue of the evolution of economic phenomena that influence one another. First of all, we introduce a geometric model to establish whether there is a direct influence between two economic phenomena. After this, we find out the strength of this influence and, finally, we suggest a model for the form of this influence.Key words: economic phenomenon; evolution; development; increase; decrease
A HOLISTIC APPROACH OF RELATIONSHIP MARKETING IN LAUNCHING LUXURY NEW PRODUCTS
On the basis of increased complexity of the exchange mechanism, at the beginning of the third millennium the contemporary marketing suffers some physiognomic changes. Holistic orientation of the contemporary marketing is imposed by the new dimensions therelationship marketing, holistic marketing, luxury marketing, residential complex, research on perception of luxury
Local linear convergence of alternating projections in metric spaces with bounded curvature
We consider the popular and classical method of alternating projections for
finding a point in the intersection of two closed sets. By situating the
algorithm in a metric space, equipped only with well-behaved geodesics and
angles (in the sense of Alexandrov), we are able to highlight the two key
geometric ingredients in a standard intuitive analysis of local linear
convergence. The first is a transversality-like condition on the intersection;
the second is a convexity-like condition on one set: "uniform approximation by
geodesics."Comment: Minor revisio
Basic convex analysis in metric spaces with bounded curvature
Differentiable structure ensures that many of the basics of classical convex
analysis extend naturally from Euclidean space to Riemannian manifolds. Without
such structure, however, extensions are more challenging. Nonetheless, in
Alexandrov spaces with curvature bounded above (but possibly positive), we
develop several basic building blocks. We define subgradients via projection
and the normal cone, prove their existence, and relate them to the classical
affine minorant property. Then, in what amounts to a simple calculus or duality
result, we develop a necessary optimality condition for minimizing the sum of
two convex functions
On the linear representations of the symmetry groups of single-wall carbon nanotubes
The positions of atoms forming a carbon nanotube are usually described by
using a system of generators of the symmetry group. Each atomic position
corresponds to an element of the set Z x {0,1,...,n} x {0,1}, where n depends
on the considered nanotube. We obtain an alternate rather different description
by starting from a three-axes description of the honeycomb lattice. In our
mathematical model, which is a factor space defined by an equivalence relation
in the set {(v_0,v_1,v_2)\in Z^3 | v_0+v_1+v_2\in {0,1}}, the neighbours of an
atomic position can be described in a simpler way, and the mathematical objects
with geometric or physical significance have a simpler and more symmetric form.
We present some results concerning the linear representations of single-wall
carbon nanotubes in order to illustrate the proposed approach.Comment: Major change of content. More details will be available at
http://fpcm5.fizica.unibuc.ro/~ncotfa
A Study of the Interactions Between the Double Bonds in Unsaturated Ketones
The interactions between C=C and C=O double bonds in
several unsaturated ketones have been studied by comparing
MIND0/2 caloulations wiith ionisation potentials determined by
photoelectron spectroscopy (PES). With one exception (norbornadienone)
the direct through-space interactions in conjugated .ketones
appear to be negligible, the double bonds couple hyperoonjugatively
via the intervening a bonds. This kind of approach should prove
useful for studying other long range interactions
Properties of finite Gaussians and the discrete-continuous transition
Weyl's formulation of quantum mechanics opened the possibility of studying
the dynamics of quantum systems both in infinite-dimensional and
finite-dimensional systems. Based on Weyl's approach, generalized by Schwinger,
a self-consistent theoretical framework describing physical systems
characterised by a finite-dimensional space of states has been created. The
used mathematical formalism is further developed by adding finite-dimensional
versions of some notions and results from the continuous case. Discrete
versions of the continuous Gaussian functions have been defined by using the
Jacobi theta functions. We continue the investigation of the properties of
these finite Gaussians by following the analogy with the continuous case. We
study the uncertainty relation of finite Gaussian states, the form of the
associated Wigner quasi-distribution and the evolution under free-particle and
quantum harmonic oscillator Hamiltonians. In all cases, a particular emphasis
is put on the recovery of the known continuous-limit results when the dimension
of the system increases.Comment: 21 pages, 4 figure
Synchronous reluctance machine with magnetically-coupled, double three-phase windings
Abstract: Please refer to full text to view abstract Please refer to full text to view abstrac
- …