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21.
Gianni Di Pillo Stefano Lucidi Laura Palagi 《Computational Optimization and Applications》1999,12(1-3):157-188
In this paper we describe a Newton-type algorithm model for solving smooth constrained optimization problems with nonlinear objective function, general linear constraints and bounded variables. The algorithm model is based on the definition of a continuously differentiable exact merit function that follows an exact penalty approach for the box constraints and an exact augmented Lagrangian approach for the general linear constraints. Under very mild assumptions and without requiring the strict complementarity assumption, the algorithm model produces a sequence of pairs
converging quadratically to a pair
where
satisfies the first order necessary conditions and
is a KKT multipliers vector associated to the linear constraints. As regards the behaviour of the sequence x
k alone, it is guaranteed that it converges at least superlinearly. At each iteration, the algorithm requires only the solution of a linear system that can be performed by means of conjugate gradient methods. Numerical experiments and comparison are reported. 相似文献
22.
23.
Carlo Anchisi Luciana Corda Antonio Maccioni Gianni Podda Salvatore Cabiddu 《Journal of heterocyclic chemistry》1977,14(8):1331-1336
The preparation and reaction of 1,3,2-benzodioxa- and 1,3,2-benzoxathiarsoles (IIa-b) are described. Spiran derivatives Va-c are obtained by treating IIa-b with Ia-b and triethylamine, while the reaction of IIa-b with sodium hydroxide, ethoxide and p-cresolate gives the compounds VIa-b, VIIa-b and VIIIa-b, that can evolve to Xa-b. Reaction of IIa-b with sodium p-toluenethio-late and n-butyllithium gave the compounds IXa-b and XIa-b respectively. The structure of the prepared compounds has been determined by elemental analysis and spectroscopic data. 相似文献
24.
D'Amelio N Gaggelli E Molteni E Valensin G 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2005,172(1):142-151
In this paper, we present a computer program which simulates NMR multiple quantum-filtered spectra of quadrupolar nuclei as a function of physical parameters, of the type of experiment and experimental conditions. The program works by solving relaxation theory equations for the given system, and it can be useful in order to plan the ideal conditions to set up specific experiments or to give a physical interpretation of experimental results. The program allows to independently follow the dependence of individual coherences and relaxation rates as a function of up to 50 parameters regarding the physical properties of the system under investigation, sample conditions and instrumental setup making it an helpful tool also for teaching purposes. 相似文献
25.
D'Amelio N Gaggelli E Gaggelli N Molteni E Baratto MC Valensin G Jezowska-Bojczuk M Szczepanik W 《Dalton transactions (Cambridge, England : 2003)》2004,(3):363-368
The complexes formed by kanamycin A at three different pH values (5.5, 7.4 and 12.0) were investigated by NMR and EPR spectroscopy. Paramagnetic relaxation contributions to proton relaxation rates were measured using a combination of the TOCSY sequence with the inversion recovery experiment in order to gain signal resolution in the bulk region. Measured contributions were converted into distances and used for structural determination by restrained simulated annealing where all possible chair and boat conformations of the rings were taken into account. The interaction of the Cu(II) ion with the nitrogen of the C ring is apparent at all pH values. At higher pH also the amino group of ring A starts to be involved in the metal coordination sphere. This is accompanied by a switch in conformation of ring C. Structures are consistent with the involvement in the coordination sphere either of the 2' or 4' hydroxyl oxygens at pH 5.5 and the 5 and the 6' hydroxyl oxygens (or the ring oxygen) at pH 12.0. 相似文献
26.
We recall Newtons iteration for computing the inverse or Moore–Penrose generalized inverse of a matrix. Then we specialize this approach to the case of structured matrices where all input, output and intermediate auxiliary matrices are represented in a compressed form, via their short displacement generators. We design a new Newton-like iteration based on a cubic polynomial and show its effectiveness by some numerical experiments for matrices from the Toeplitz-like class and the Cauchy-like class. 相似文献
27.
Begala M Delogu G Maccioni E Podda G Tocco G Quezada E Uriarte E Fedrigo MA Favretto D Traldi P 《Rapid communications in mass spectrometry : RCM》2001,15(12):1000-1010
A set of aminoalkoxy-substituted, differently annullated furocoumarins, differing in the position of the aminoalkoxy chain and in the unsaturation level of the fused ring, has been subjected to electron impact and electrospray ionisation (ESI) experiments. In order to achieve a distinct characterisation of isomeric compounds, which partially failed under electron impact conditions, collision-induced dissociation experiments were performed on protonated molecules. The breakdown curves obtained by varying the tickle voltage on an ion trap ESI instrument led to the desired characterisation. 相似文献
28.
We compute the -limit of a sequence obstacle functionals in the case of periodic obstacles. 相似文献
29.
Gianni Bosi Juan Carlos Candeal Esteban Induráin Esteban Oloriz Margarita Zudaire 《Order》2001,18(2):171-190
In the framework of the analysis of orderings whose associated indifference relation is not necessarily transitive, we study the structure of an interval order and its representability through a pair of real-valued functions. We obtain a list of characterizations of the existence of a representation, showing that the three main techniques that have been used in the literature to achieve numerical representations of interval orders are indeed equivalent. 相似文献
30.
Roberto Gianni Paola Mannucci 《NoDEA : Nonlinear Differential Equations and Applications》2001,8(2):219-235
We prove a well posedness result for a free boundary problem describing the filtration of an incompressible viscous fluid
in a porous medium containing water absorbing granules.?The location of the wetting front (the free boundary) is described
by a Stefan like problem for a parabolic equation which is coupled with an hyperbolic equation describing the absorption kinetic
of the granules.
Received December 1999 相似文献