1,721,602 research outputs found
Fulga - izolare și participare comunitară: Fulga - Between Isolation and Participation
No full textIn this paper social exchange relations, association and entrepreneurship as responses to community problems and a low level of local opportunities are studied in a geographical and social isolated Romanian plain commune. The two villages of Fulga commune are traditional communities characterized by strong norms of similarity and conservative values. Trust, openness or other modernity values do not sustain associations and collective actions but the citizens' participation could be situationally motivated. The high proportion of population involved in agricultural field and the number of people eligible for social benefits grater than the number of occupied people are correlated with low levels of human capital and living standard. There are few private initiatives, which are oriented to survival and short-term achievement and they have almost nothing to do with social and economic history of the commune but life history of those involved in
Double Weyl points and Fermi arcs of topological semimetals in non-Abelian gauge potentials
No full textWe study the effect of a non-Abelian SU(2) gauge potential mimicking spin-orbit coupling on the topological semimetal induced by a magnetic field having pi flux per plaquette and acting on fermions in a three-dimensional (3D) cubic lattice. The Abelian pi-flux term gives rise to a spectrum characterized by Weyl points. The non-Abelian term is chosen to be gauge equivalent to both a 2D Rashba and a Dresselhaus spin-orbit coupling. As a result of the anisotropic nature of the coupling between spin and momentum and of the presence of a C-4 rotation symmetry, when the non-Abelian part is turned on, the Weyl points assume a quadratic dispersion along two directions and constitute double monopoles for the Berry curvature. We examine the main features of this system both analytically and numerically, focusing on its gapless surface modes, the so-called Fermi arcs. We discuss the stability of the system under confining hard-wall and harmonic potentials, relevant for the implementation in ultracold atom settings, and the effect of rotation symmetry breaking. © 2016 American Physical Society
Exact diagonalization of cubic lattice models in commensurate Abelian magnetic fluxes and translational invariant non-Abelian potentials
No full textPT invariant Weyl semimetals in gauge symmetric systems
No full textWeyl semimetals typically appear in systems in which either time-reversal (T) or inversion (P) symmetry is broken. Here we show that in the presence of gauge potentials these topological states of matter can also arise in fermionic lattices preserving both T and P. We analyze in detail the case of a cubic lattice model with π fluxes, discussing the role of gauge symmetries in the formation of Weyl points and the difference between the physical and the canonical T and P symmetries. We examine the robustness of this PT-invariant Weyl semimetal phase against perturbations that remove the chiral sublattice symmetries, and we discuss further generalizations. Finally, motivated by advances in ultracold-atom experiments and by the possibility of using synthetic magnetic fields, we study the effect of random perturbations of the magnetic fluxes, which can be compared to a local disorder in realistic scenarios. © 2016 American Physical Society
Some Results on S-<i>contractions</I> of Type <i>e</I>
No full textFulga, Andreea/0000-0002-6689-0355; KARAPINAR, ERDAL/0000-0002-6798-3254In this manuscript, we consider the compositions of simulation functions and E-contraction in the setting of a complete metric space. We investigate the existence and uniqueness of a fixed point for this composite form. We give some illustrative examples and provide an application
3D-Druck industrietauglich machen
No full textS.31-33Im industriellen Bereich hat der 3D-Druck ein großes Manko. Denn bislang hat es an wirksamen Qualitätskontrollen für die gefertigten Bauteile gefehlt. Aus diesem Grund entwickelte Simina Fulga-Beising im Rahmen ihrer Dissertation ein Inline-Kontrollsystem, das auf maschinelles Sehen setzt und sich maschinenunabhängig anbringen lässt. Damit lassen sich Fehler an den Bauteilen schon während des Druckprozesses erkennen.Nr.
Revisiting of Some Outstanding Metric Fixed Point Theorems Via <i>e</I>-contraction
No full textFulga, Andreea/0000-0002-6689-0355; KARAPINAR, ERDAL/0000-0002-6798-3254In this paper, we introduce the notion of alpha-psi-contractive mapping of type E, to remedy of the weakness of the existing contraction mappings. We investigate the existence and uniqueness of a fixed point of such mappings. We also list some examples to illustrate our results that unify and generalize the several well-known results including the famous Banach contraction mapping principle
A Short Note on the Common Fixed Points of the Geraghty Contraction of Type <i>e<sub>s</Sub><
No full textFulga, Andreea/0000-0002-6689-0355; KARAPINAR, ERDAL/0000-0002-6798-3254In this paper, we propose a new contraction type for two self-mappings and investigate the necessary conditions for the existence and uniqueness of coincidence points and common fixed points, respectively. We put some examples to illustrate our main results
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