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71.
E. A. Papa Quiroz P. R. Oliveira 《Journal of Optimization Theory and Applications》2007,135(3):475-490
We introduce a new barrier function to build new interior-point algorithms to solve optimization problems with bounded variables.
First, we show that this function is a (3/2)n-self-concordant barrier for the unitary hypercube [0,1]
n
, assuring thus the polynomial property of related algorithms. Second, using the Hessian metric of that barrier, we present
new explicit algorithms from the point of view of Riemannian geometry applications. Third, we prove that the central path
defined by the new barrier to solve a certain class of linearly constrained convex problems maintains most of the properties
of the central path defined by the usual logarithmic barrier. We present also a primal long-step path-following algorithm
with similar complexity to the classical barrier. Finally, we introduce a new proximal-point Bregman type algorithm to solve
linear problems in [0,1]
n
and prove its convergence.
P.R. Oliveira was partially supported by CNPq/Brazil. 相似文献
72.
M. Sandoli L. Campajola A. De Rosa A. D’Onofrio G. Inglima M. La Commara A. Ordine D. Pierroutsakou V. Roca M. Romano M. Romoli F. Terrasi M. Trotta G. Cardella M. Papa G. Pappalardo F. Rizzo N. Alamanos F. Auger A. Gillibert 《Zeitschrift für Physik A Hadrons and Nuclei》1997,357(1):67-74
The energy spectra of the γ-rays emitted in the 35Cl + 92Mo reaction at incident energy E = 260 MeV were measured in coincidence with the ejectiles produced in dissipative reaction events. The cumulative energy spectrum of the γ-rays coming from the decay of the ejectiles was calculated within the statistical model and its comparison to the experimental spectrum evidences an excess in the data for E γ = 8 to 12 MeV. Such an excess, fitted with a Lorentz curve, is attributed to the preequilibrium GDR γ-decay of the intermediate dinuclear system. The centroid energy of the Lorentz curve corresponds to a dipole oscillation along the symmetry axis of the system and its width is found to be comparable to that of the ground state GDR low energy component of the deformed dinucleus. The small quantal dispersion Δ? = (10.3 ± 0.1)? of the entrance channel angular momentum, determined by analysing the dissipative fragment angular distribution in the framework of the Strutinsky model, is suggested to limit the broadening of the preequilibrium GDR width. 相似文献
73.
Anna Laura Capriotti Grazia Maria Borrelli Valentina Colapicchioni Roberto Papa Susy Piovesana Roberto Samperi Serena Stampachiacchiere Aldo Laganà 《Analytical and bioanalytical chemistry》2014,406(5):1423-1435
Salinity is one of the major abiotic stress conditions limiting crop growth and productivity. Duilio is a wheat genotype that shows tolerant behavior in both salt-stress and drought-stress conditions. Toward better understanding of the biochemical response to salinity in this genotype of durum wheat, a comparative label-free shotgun proteomic analysis based on normalized spectral abundance factors was conducted on wheat leaf samples subjected to increasing salt-stress levels (100 and 200 mmol L-1 NaCl) with respect to untreated samples. We found significant changes in 71 proteins for the first stress level, in 83 proteins at the higher salinity level, and in 88 proteins when comparing salt-stress levels with each other. The major changes concerned the proteins involved in primary metabolism and production of energy, followed by those involved in protein metabolism and cellular defense mechanisms. Some indications of different specific physiological and defense mechanisms implicated in increasing tolerance were obtained. The enhanced salinity tolerance in Duilio appeared to be governed by a higher capacity for osmotic homeostasis, a more efficient defense, and an improvement of protection from mechanical stress by increased cell wall lignifications, allowing a better potential for growth recovery. 相似文献
74.
AbstractThis paper is devoted to the study of proximal distances defined over symmetric cones, which include the non-negative orthant, the second-order cone and the cone of positive semi-definite symmetric matrices. Specifically, our first aim is to provide two ways to build them. For this, we consider two classes of real-valued functions satisfying some assumptions. Then, we show that its corresponding spectrally defined function defines a proximal distance. In addition, we present several examples and some properties of this distance. Taking into account these properties, we analyse the convergence of proximal-type algorithms for solving convex symmetric cone programming (SCP) problems, and we study the asymptotic behaviour of primal central paths associated with a proximal distance. Finally, for linear SCP problems, we provide a relationship between the proximal sequence and the primal central path. 相似文献
75.
Adam J Bai X Baldini AM Baracchini E Bemporad C Boca G Cattaneo PW Cavoto G Cei F Cerri C de Bari A De Gerone M Doke T Dussoni S Egger J Fratini K Fujii Y Galli L Gallucci G Gatti F Golden B Grassi M Grigoriev DN Haruyama T Hildebrandt M Hisamatsu Y Ignatov F Iwamoto T Kettle PR Khazin BI Kiselev O Korenchenko A Kravchuk N Maki A Mihara S Molzon W Mori T Mzavia D Natori H Nicolò D Nishiguchi H Nishimura Y Ootani W Panareo M Papa A Pazzi R Piredda G Popov A Renga F Ritt S Rossella M Sawada R 《Physical review letters》2011,107(17):171801
We present a new result based on an analysis of the data collected by the MEG detector at the Paul Scherrer Institut in 2009 and 2010, in search of the lepton-flavor-violating decay μ(+)e(+)γ. The likelihood analysis of the combined data sample, which corresponds to a total of 1.8×10(14) muon decays, gives a 90% C.L. upper limit of 2.4×10(-12) on the branching ratio of the μ(+)→e(+)γ decay, constituting the most stringent limit on the existence of this decay to date. 相似文献
76.
Let V=V(n,q) denote the finite vector space of dimension n over the finite field with q elements. A subspace partition of V is a collection Π of subspaces of V such that each 1-dimensional subspace of V is in exactly one subspace of Π. In a recent paper, we proved some strong connections between the lattice of the subspace partitions of V and the lattice of the set partitions of n={1,…,n}. We now define a Gaussian partition of [n]
q
=(q
n
−1)/(q−1) to be a nonincreasing sequence of positive integers formed by ordering all elements of some multiset {dim(W):W∈Π}, where Π is a subspace partition of V. The Gaussian partition function gp(n,q) is then the number of all Gaussian partitions of [n]
q
, and is naturally analogous to the classical partition function p(n). In this paper, we initiate the study of gp(n,q) by exhibiting all Gaussian partitions for small n. In particular, we determine gp(n,q) as a polynomial in q for n≤5, and find a lower bound for gp(6,q). 相似文献
77.
Many-body correlations generated by the symmetry potential naturally arise in the molecular-dynamics CoMD-II model. The effect
of these correlations on the collision dynamics at Fermi energies is discussed. In particular we show that two-body correlations
generated by the symmetry potential are able to produce large effects in simple observables such as the charge distributions.
A comparison with the predictions, based on EOS static calculations, is also discussed. 相似文献
78.
Problem-dependent interpolation functions for displacements and rotations are obtained from the exact analytical solution of the 3D Timoshenko beam problem by introducing a full set of boundary conditions. The developed methodology allows us to derive a new solution that coincides with the classical result of the engineering beam theory. In addition, the proposed interpolation enables exact strain recovery at any point within the problem domain. 相似文献
79.
S. A. Wymer J. S. Popovics M. Churma R. Hollinger B. Howland F. Papa B. Shanker J. Terosky 《International Journal of Infrared and Millimeter Waves》1994,15(6):1105-1124
This work is a collection of selected, significant references focussing upon magnetic materials and their interaction with electromagnetic fields. The major topics included are ferrites, plasmas (both atmospheric and laboratory), magnetic composites, magnetic dielectric fluids, ferroelectric liquid crystals. Sections discussing general magnetic materials and phenomena are also included. 相似文献
80.
A.L.S. Angelis H.-J. Besch B.J. Blumenfeld L. Camilleri T.J. Chapin R.L. Cool C. Del Papa L. Di Lella Z. Dimčovski R.J. Hollebeek L.M. Lederman D.A. Levinthal J.T. Linnemann C.B. Newman N. Phinney B.G. Pope S.H. Pordes K.K. Young 《Physics letters. [Part B]》1980,94(1):106-112
As part of a study of large pT phenomena in photon-proton collisions at the CERN ISR, a search for direct single photon production has been performed. A statistical division of the data sample into the fraction consistent with single photon and the fraction due to multiphoton decays of neutral hadrons is accomplished by measuring the average conversion probability for the sample in a one radiation length thick converter. The fraction of the sample attributable to direct single photon production is 〈γ/all〉 = 0.074 ± 0.012 for 6 GeV/c < pT 10 GeV/c, and 〈γ/all〉 = 0.26 ± 0.04 for pT > 10 GeV/c, with an additional systematic uncertainty of ±0.05 for both values. 相似文献