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 $d$ of the system increases.Comment: 21 pages, 4 figure

Synchronous reluctance machine with magnetically-coupled, double three-phase windings

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