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41.
Vittoria de Nitto Personè 《Annals of Operations Research》2009,170(1):95-112
The aim of this paper is to improve the machine interference model with vacation to deal with more recent problems of the
communication area. To this scope the model is extended to include parallelism in the vacation station. The underlying Markov
process is analyzed and a state arrangement is found that yields an efficient matrix-analytic technique that substantially
lowers down the time- and space-complexity of standard methods. A numerical example of the method effectiveness is presented,
and an example of resource allocation is introduced that finds applications in the QoS management of wireless networks.
The author is thankful to the anonymous referees for the improvements their comments have earned to the quality of the presentation
and to the completeness of the paper. The author is thankful to Giuseppe Iazeolla, whose careful reading of the original draft
of this paper led to significant improvements in its overall quality. This work was partially supported by funds from the
FIRB project “Performance Evaluation of Complex Systems: Techniques Methodologies and Tools” and by the University of Roma
TorVergata project on High Performance ICT Platforms. 相似文献
42.
Nicoletta Panziera Ilaria Fratoddi Maria Vittoria Russo 《Journal of organometallic chemistry》2006,691(12):2648-2656
The new dialkynylated complexes Ru(η6-DEB-Si)(η4-COD), 4a, Ru(η6-DEBP-Si)(η4-COD), 4b1, Ru2(η6,η6-DEBP)(η4-COD)2, 4b2 [COD = 1,5-cyclooctadiene; DEB-Si = 1,4-bis(trimethylsilylethynyl)benzene; DEBP-Si = 4,4′-bis(trimethylsilylethynyl)biphenyl] have been synthesized by the arene exchange reaction with the complex Ru(η6-naphthalene)(η4-COD). The complexes Ru(η6-DEB)(η4-COD), 5a, and Ru(η6-DEBP)(η4-COD), 5b1, have been prepared by desilylation of the corresponding compounds 4a and 4b1. All the complexes have been fully characterized by means of spectroscopic techniques. 相似文献
43.
Moving from the observation that drainage network configurations minimizing total energy dissipation are stationary solutions of the general equation describing landscape evolution, we review theoretical and observational evidence on river patterns and their scale-invariant structure. Exact results complemented by numerical annealing of the basic equation in the presence of additive noise suggest that configurations at (or very close to) the global minimum of energy dissipation differ from dynamically accessible states, which have rather different scaling properties and conform much better to natural forms. Thus we argue that, at least in the fluvial landscape, Nature works through imperfect searches for dynamically accessible optimal configurations. We also show that optimal networks are spanning loopless configurations only under precise physical requirements. This is stated in a form applicable to generic networks, suggesting that other branching structures occurring in Nature (e.g. scale-free and looping) may possibly arise through optimality to selective pressures. Indeed, we show that this is the case. 相似文献
44.
Hierarchical structures in fibrillar collagens 总被引:6,自引:0,他引:6
Ottani V Martini D Franchi M Ruggeri A Raspanti M 《Micron (Oxford, England : 1993)》2002,33(7-8):587-596
45.
Andrew P. Daigle Michael Geiler Anton Geiler Eric DuPré Jacob Modest Yajie Chen Carmine Vittoria Vincent G Harris. 《Journal of magnetism and magnetic materials》2012
Co2Z hexaferrite materials possess intrinsically high permeability, zero field ferromagnetic resonance values (∼1 GHz), and have their magnetic orientation in the plane perpendicular to the c-axis. These characteristics make these materials practical for applications in low to mid ultra-high frequency and L-band microwave device designs. Due to the relatively large size of elements operating within these bands, it has become important to produce large amounts of Co2Z type hexaferrite materials. A modified co-precipitation method has been proposed to produce scalable quantities of high quality Co2Z hexaferrite particles, at ∼24 g/L. These particles have been thoroughly characterized by vibrating sample magnetometry (VSM) and X-ray diffraction (XRD) with regard to phase purity and magnetic properties. After formation and subsequent ball milling, to achieve single domain particles on the order of 0.5–2 um, particles were oriented and pressed into compacts inside a rotating field to ensure magnetization in plane. Samples then underwent VSM, XRD, and scanning electron microscopy to determine the orientation effect. In addition, the complex permittivity and permeability of these samples were measured as a function of applied field and processing conditions. The results show strong orientation in these compacts making them practical for a variety of device applications. 相似文献
46.
Riccardo Fazio Salvatore Iacono Alessandra Jannelli Giovanni Cavaccini Vittoria Pianese 《PAMM》2007,7(1):2150003-2150004
This is a mathematical and numerical study of liquid dynamics in a horizontal capillary. We present a two-liquids model which takes into account the effects of real phenomena like the outside flow dynamics. Moreover, we report on results obtained by an adaptive numerical method. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
47.
Carlo Castellari Fabio Comelli Stefano Ottani 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(10):1182-1183
In the solid-state structure of the title compound, C4H10N+·C14H10Cl2NO2−·H2O, the asymmetric unit contains one cation, one anion and a water molecule. There is a network of hydrogen bonds which is similar to that found in the hydrated diethylammonium diclofenac salt. A comparison is made of the molecular conformation of the anions in the two related structures. 相似文献
48.
49.
Fabrizio Melani Lucia Cecchi Vittoria Colotta Giovanna Palazzino Guido Filacchioni 《Journal of heterocyclic chemistry》1988,25(5):1367-1371
By reacting 2-chloronicotinoyl chloride with acetyl or benzoyl acetate, ethyl 2-methyl- or 2-phenyl-4-oxopyrano[2,3-b]pyridine-3-carboxylates were prepared. The nucleophilic rearrangement of the latter with hydrazines gave rise to the title compounds. 相似文献
50.
Maria Vittoria Barbarulo Francesca Buiarelli Massino Ciardi Alberto Giarrusso Felice Rosati G. P. Cartoni 《Journal of separation science》1995,18(11):705-708
The metabolism of oxabolone cipionate, 17-(3-cyclopentyl-1-oxopropoxy)-4-hydroxyestr-4-en-3-one, a synthetic anabolic steroid, was investigated in man, the cumulative urinary excretion and the metabolism of the compounds being studied by GC-MS in both electron impact and chemical ionization modes. After administration by injection to volunteers, five different metabolities were detected in urine. The metabolites and the parent compound were detected in urine up to a week after administration. 相似文献