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991.
992.
We study a nonlinear Schrödinger equation in presence of a magnetic field and relate the number of solutions with the topology of the set where the potential attains its minimum value. In the proofs we apply variational methods, penalization techniques and Ljusternik–Schnirelmann theory. 相似文献
993.
In previous work, Costa and Alves (J Math Sci 161:(6)820–831, 2009; 2011) have presented Branch & Bound and Branch & Cut techniques that allow for the effective computation of nondominated solutions, associated with reference points, of multi-objective linear fractional programming (MOLFP) problems of medium dimensions (ten objective functions, hundreds of variables and constraints). In this paper we present some results that enhance those computations. Firstly, it is proved that the use of a special kind of achievement scalarizing function guarantees that the computation error does not depend on the dimension of the problem. Secondly, a new cut for the Branch & Cut technique is presented. The proof that this new cut is better than the one in Costa and Alves (2011) is presented, guaranteeing that it reduces the region to explore. Some computational tests to assess the impact of the new cut on the performance of the Branch & Cut technique are presented. 相似文献
994.
Sandra Mara Alves Jorge 《代数通讯》2013,41(6):2184-2198
995.
M. C. Câmara Yu. I. Karlovich I. M. Spitkovsky 《Complex Analysis and Operator Theory》2013,7(2):375-407
Necessary and sufficient factorability conditions are established for some new classes of almost periodic matrix functions, and explicit factorization formulas are given whenever the factorization exists. The results are based on the connection between factorability and properties of solutions to a related homogeneous Riemann–Hilbert problem. These solutions, in their turn, are described completely, for the cases at hand, via introduction and consideration of certain asymmetric Toeplitz operators. 相似文献
996.
R. Alves de Souza 《Revista Internacional de Métodos Numéricos para Cálculo y Dise?o en Ingeniería》2013,29(1):38-51
Reinforced concrete elements subjected to membrane forces, i.e., elements subjected to in-plane shear and axial stresses are very common for modeling complex structures such as aircraft hangars, nuclear power plants, offshore oil platforms and long-span bridges. While the design of reinforcement for membrane elements is well adressed the same can not be said regarding the analysis of performance of these elements. Into this context, the present paper aims at providing a numerical tool developed in the Matlab platform, taking into account the “Modified Compression Field Theory”. In order to certificate the performance of the proposed tool, extensive numerical results were compared with experimental results available in the literature. The obtained results revealed that the proposed tool is very confident for the analysis of reinforced concrete membrane elements. 相似文献
997.
José F. Alves Carla L. Dias Stefano Luzzatto 《Annales de l'Institut Henri Poincaré (C) Analyse Non Linéaire》2013
We show that for a large class of maps on manifolds of arbitrary finite dimension, the existence of a Gibbs–Markov–Young structure (with Lebesgue as the reference measure) is a necessary as well as sufficient condition for the existence of an invariant probability measure which is absolutely continuous measure (with respect to Lebesgue) and for which all Lyapunov exponents are positive. 相似文献
998.
Marian Vâjâitu 《Algebras and Representation Theory》2013,16(6):1611-1620
Given a prime number p and K a compact subset of ? p , the topological completion of the algebraic closure of the field of p-adic numbers, we are interested in integral representations for a class of Krasner analytic functions defined on ${\mathbb{P}}^1({\mathbb{C}}_p)\setminus K$ with values in ${\mathbb{P}}^1({\mathbb{C}}_p)$ . We apply these results to study the behavior of Krasner analytic functions around singular points. 相似文献
999.
Victor Alexandru Nicolae Popescu Marian Vâjâitu Alexandru Zaharescu 《Algebras and Representation Theory》2013,16(3):895-904
Given a prime number p and a compact subset X of the topological completion ? p of the algebraic closure of the field of p-adic numbers, we study the set of zeros of Krasner analytic functions defined on ?1(? p ) \ X with values in ? p . 相似文献
1000.
RM Maria TB Moraes CJ Magon T Venâncio WF Altei AD Andricopulo LA Colnago 《The Analyst》2012,137(19):4546-4551
Proton nuclear magnetic resonance ((1)H NMR) spectroscopy for detection of biochemical changes in biological samples is a successful technique. However, the achieved NMR resolution is not sufficiently high when the analysis is performed with intact cells. To improve spectral resolution, high resolution magic angle spinning (HR-MAS) is used and the broad signals are separated by a T(2) filter based on the CPMG pulse sequence. Additionally, HR-MAS experiments with a T(2) filter are preceded by a water suppression procedure. The goal of this work is to demonstrate that the experimental procedures of water suppression and T(2) or diffusing filters are unnecessary steps when the filter diagonalization method (FDM) is used to process the time domain HR-MAS signals. Manipulation of the FDM results, represented as a tabular list of peak positions, widths, amplitudes and phases, allows the removal of water signals without the disturbing overlapping or nearby signals. Additionally, the FDM can also be used for phase correction and noise suppression, and to discriminate between sharp and broad lines. Results demonstrate the applicability of the FDM post-acquisition processing to obtain high quality HR-MAS spectra of heterogeneous biological materials. 相似文献