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101.
Aitala EM Amato S Anjos JC Appel JA Ashery D Banerjee S Bediaga I Blaylock G Bracker SB Burchat PR Burnstein RA Carter T Carvalho HS Copty NK Costa I Cremaldi LM Darling C Denisenko K Fernandez A Gagnon P Gerzon S Gobel C Gounder K Halling AM Herrera G Hurvits G James C Kasper PA Kwan S Langs DC Leslie J Lundberg B MayTal-Beck S Meadows B de Mello Neto JR Milburn RH de Miranda JM Napier A Nguyen A d'Oliveira AB O'Shaughnessy K Peng KC Perera LP Purohit MV Quinn B Radeztsky S Rafatian A 《Physical review letters》1996,77(12):2384-2387
102.
The floorplanning (or facility layout) problem consists in finding the optimal positions for a given set of modules of fixed
area (but perhaps varying height and width) within a facility such that the distances between pairs of modules that have a
positive connection cost are minimized. This is a hard combinatorial optimization problem; even the restricted version where
the shapes of the modules are fixed and the optimization is taken over a fixed finite set of possible module locations is
NP-hard. In this paper, we extend the concept of target distance introduced by Etawil and Vannelli and apply it to derive
the AR (Attractor-Repeller) model which is designed to improve upon the NLT method of van Camp et al. This new model is designed
to find a good initial point for the Stage-3 NLT solver and has the advantage that it can be solved very efficiently using
a suitable optimization algorithm. Because the AR model is not a convex optimization problem, we also derive a convex version
of the model and explore the generalized target distances that arise in this derivation. Computational results demonstrating
the potential of our approach are presented. 相似文献
103.
Let R be a local ring with maximal ideal ${\mathfrak{m}}$ admitting a non-zero element ${a\in\mathfrak{m}}$ for which the ideal (0 : a) is isomorphic to R/aR. We study minimal free resolutions of finitely generated R-modules M, with particular attention to the case when ${\mathfrak{m}^4=0}$ . Let e denote the minimal number of generators of ${\mathfrak{m}}$ . If R is Gorenstein with ${\mathfrak{m}^4=0}$ and e ?? 3, we show that ${{\rm P}_{M}^{R}(t)}$ is rational with denominator H R (?t) =?1 ? et?+?et 2 ? t 3, for each finitely generated R-module M. In particular, this conclusion applies to generic Gorenstein algebras of socle degree 3. 相似文献
104.
Ibolya Jankovits Chaomin Luo Miguel F. Anjos Anthony Vannelli 《European Journal of Operational Research》2011,214(2):199-215
The unequal-areas facility layout problem is concerned with finding the optimal arrangement of a given number of non-overlapping indivisible departments with unequal area requirements within a facility. We present a convex-optimisation-based framework for efficiently finding competitive solutions for this problem. The framework is based on the combination of two mathematical programming models. The first model is a convex relaxation of the layout problem that establishes the relative position of the departments within the facility, and the second model uses semidefinite optimisation to determine the final layout. Aspect ratio constraints, frequently used in facility layout methods to restrict the occurrence of overly long and narrow departments in the computed layouts, are taken into account by both models. We present computational results showing that the proposed framework consistently produces competitive, and often improved, layouts for well-known large instances when compared with other approaches in the literature. 相似文献
105.
This paper explores new connections between the satisfiability problem and semidefinite programming. We show how the process of resolution in satisfiability is equivalent to a linear transformation between the feasible sets of the relevant semidefinite programming problems. We call this transformation semidefinite programming resolution, and we demonstrate the potential of this novel concept by using it to obtain a direct proof of the exactness of the semidefinite formulation of satisfiability without applying Lasserre’s general theory for semidefinite relaxations of 0/1 problems. In particular, our proof explicitly shows how the exactness of the semidefinite formulation for any satisfiability formula can be interpreted as the implicit application of a finite sequence of resolution steps to verify whether the empty clause can be derived from the given formula. 相似文献
106.
Rajendra M. Srivastava Maria C. Pereira Wagner W. M. Faustino Kaline Coutinho Janaína V. dos Anjos Sebasti?o J. de Melo 《Monatshefte für Chemie / Chemical Monthly》2009,15(2):1319-1324
Abstract
A simple and easy synthesis of ten arylamidoximes from arylnitriles and hydroxylamine is described. The formation of the arylamides has been observed to a much lesser extent in the present work. A new mechanism for the formation of arylamidoximes, as well as arylamides, from arylnitriles and hydroxylamine is suggested. Quantum mechanical calculations have been carried out to support this mechanism. The enthalpy of formation in conjunction with atomic charges of the reactants and intermediates helped to understand more about the generation of the products. 相似文献107.
Gold nanoparticles (AuNPs) have been synthesized by greener method using chloroauric acid as precursor and extract of Acorus calamus rhizome as reducing agent. Formation of AuNP was confirmed by the presence of Surface Plasmon Resonance (SPR) peak in UV–Visible spectral analysis. XRD and FT-IR spectral analyses were performed for characterization. SEM images show spherical morphology and HR-TEM images reveal nanosize of AuNPs. The AuNPs were then coated on cotton fabric by pad-dry-cure method and characterized by SEM with EDAX technique. The results reveal the deposition of AuNPs on the surface of cotton fabric. Uncoated cotton, neat extract coated cotton and extract containing AuNPs coated cotton fabrics were then tested for antibacterial activity against Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli) bacterial strains by AATCC 100 test method. It showed that the extract containing AuNPs coated cotton fabric had higher antibacterial activity than other test samples against E. coli. UV-DRS analysis performed on extract containing AuNPs coated cotton fabric showed improved UV-blocking property than uncoated cotton fabric and neat extract coated cotton fabric. 相似文献
108.
C. Calza M.J. Anjos S.M.F. Mendonça de Souza A. Brancaglion Jr. R.T. Lopes 《Applied Physics A: Materials Science & Processing》2008,90(1):75-79
In this work, X-ray microfluorescence with the synchrotron radiation technique was applied in the analysis of pigments found
in decorative paintings in the sarcophagus of an Egyptian mummy. This female mummy, from the Roman Period, which was embalmed
with the arms and legs swathed separately is considered one of the most important pieces of the Egyptian Collection from the
National Museum (Rio de Janeiro, Brazil). The measurements were performed at the XRF beamline D09B of the Brazilian Synchrotron
Light Laboratory (LNLS), using the white beam and a Si(Li) detector with resolution of 165 eV at 5.9 keV. The possible pigments
found in the samples were: Egyptian blue, Egyptian green frit, green earth, verdigris, malachite, ochre, realgar, chalk, gypsum,
bone white, ivory black and magnetite. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were applied
to the results in order to verify if the samples belong to the same period of a linen wrapping fragment, whose provenance
was well established.
PACS 07.85.Nc; 07.85.Qe; 78.70.En 相似文献
109.
Aitala EM Amato S Anjos JC Appel JA Ashery D Banerjee S Bediaga I Blaylock G Bracker SB Burchat PR Burnstein RA Carter T Carvalho HS Copty NK Cremaldi LM Darling C Denisenko K Devmal S Fernandez A Fox GF Gagnon P Gerzon S Gobel C Gounder K Halling AM Herrera G Hurvits G James C Kasper PA Kwan S Langs DC Leslie J Lichtenstadt J Lundberg B MayTal-Beck S Meadows B de Mello Neto JR Mihalcea D Milburn RH de Miranda JM Napier A Nguyen A d'Oliveira AB O'Shaughnessy K Peng KC Perera LP Purohit MV 《Physical review letters》2001,86(21):4773-4777
We have studied the diffractive dissociation into dijets of 500 GeV/c pions scattering coherently from carbon and platinum targets. Extrapolating to asymptotically high energies (where t(min)-->0), we find that when the per-nucleus cross section for this process is parametrized as sigma = sigma0Aalpha, alpha has values near 1.6, the exact result depending on jet transverse momentum. These values are in agreement with those predicted by theoretical calculations of color-transparency. 相似文献
110.
Aitala EM Amato S Anjos JC Appel JA Ashery D Banerjee S Bediaga I Blaylock G Bracker SB Burchat PR Burnstein RA Carter T Carvalho HS Copty NK Cremaldi LM Darling C Denisenko K Deval S Fernandez A Fox GF Gagnon P Gerzon S Gobel C Gounder K Halling AM Herrera G Hurvits G James C Kasper PA Kwan S Langs DC Leslie J Lichtenstadt J Lundberg B MayTal-Beck S Meadows B de Mello Neto JR Mihalcea D Milburn RH de Miranda JM Napier A Nguyen A d'Oliveira AB O'Shaughnessy K Peng KC Perera LP Purohit MV 《Physical review letters》2001,86(21):4768-4772
We present the first direct measurements of the pion valence-quark momentum distribution which is related to the square of the pion light-cone wave function. The measurements were carried out using data on diffractive dissociation of 500 GeV/c pi(-) into dijets from a platinum target at Fermilab experiment E791. The results show that the /q&q> light-cone asymptotic wave function describes the data well for Q2 approximately 10 (GeV/c)(2) or more. We also measured the transverse momentum distribution of the diffractive dijets. 相似文献