43,161 research outputs found
Computing the -coverage of a wireless network
Coverage is one of the main quality of service of a wirelessnetwork.
-coverage, that is to be covered simultaneously by network nodes, is
synonym of reliability and numerous applicationssuch as multiple site MIMO
features, or handovers. We introduce here anew algorithm for computing the
-coverage of a wirelessnetwork. Our method is based on the observation that
-coverage canbe interpreted as layers of -coverage, or simply
coverage. Weuse simplicial homology to compute the network's topology and
areduction algorithm to indentify the layers of -coverage. Weprovide figures
and simulation results to illustrate our algorithm.Comment: Valuetools 2019, Mar 2019, Palma de Mallorca, Spain. 2019. arXiv
admin note: text overlap with arXiv:1802.0844
Collective oscillations of a Fermi gas near a Feshbach resonance
A sum rule approach is used to calculate the zero temperature oscillation
frequencies of a two component trapped atomic Fermi gas in the BCS-Bose
Einstein condensation crossover region. These sum rules are evaluated using a
local density approximation which explicitly includes Feshbach molecules.
Breathing modes show non-monotonic behavior as a function of the interaction
strength, while quadrupole modes are insensitive to interactions for both
spherically symmetric and axially symmetric traps. Quantitative agreement is
found with experiments on atomic system and with other theoretical
approaches.Comment: 7 pages, 4 figure
Dipole-induced vortex ratchets in superconducting films with arrays of micromagnets
We investigate the transport properties of superconducting films with
periodic arrays of in-plane magnetized micromagnets. Two different magnetic
textures are studied: a square array of magnetic bars and a close-packed array
of triangular microrings. As confirmed by MFM imaging, the magnetic state of
both systems can be adjusted to produce arrays of almost point-like magnetic
dipoles. By carrying out transport measurements with ac drive, we observed
experimentally a recently predicted ratchet effect induced by the interaction
between superconducting vortices and the magnetic dipoles. Moreover, we find
that these magnetic textures produce vortex-antivortex patterns, which have a
crucial role on the transport properties of this hybrid system.Comment: 4 pages, 4 figure
Surface Tension in Unitary Fermi Gases with Population Imbalance
We study the effects of surface tension between normal and superfluid regions
of a trapped Fermi gas at unitarity. We find that surface tension causes
notable distortions in the shape of large aspect ratio clouds. Including these
distortions in our theories resolves many of the apparent discrepancies among
different experiments and between theory and experiments.Comment: 4 pages, 4 figures, Published versio
Perfil das comunidades quilombolas paraibanas: índice de vulnerabilidade socioeconômica e ecológica para o desenvolvimento sustentável local - ISE.
O estudo possibilitou definir as dimensões: social, econômica e ecológica das comunidades quilombolas paraibanas. A situação de vulnerabilidade de cada Grupo (cluster means) foi codificada e geoespacializada em um Sistema Geográfico de Informação (SGI) por setor censitário do Estado da Paraíba, após a construção de um índice classificatório correspondente as 38 comunidades quilombolas pesquisadas in loco. Os perfis das Comunidades apresentados para o conjunto do Índice de vulnerabilidade socioeconômica e ecológica (ISE) foram altamente significativos, identificando a necessidade de políticas públicas mais efetivas, por localidades, simplificando significativamente, o investimento dos Programas socioambientais já previstos pelos governos: federal, estadual e municipais em benefício da região
As edificações e os detalhes construtivos voltados para o manejo de dejetos na suinocultura
bitstream/item/58213/1/doc113.pdfProjeto de controle da degradação ambiental decorrente da suinocultura em Santa Catarina
- …