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991.
992.
We consider the global and local convergence properties of a class of Lagrangian barrier methods for solving nonlinear programming problems. In such methods, simple bound constraints may be treated separately from more general constraints. The objective and general constraint functions are combined in a Lagrangian barrier function. A sequence of such functions are approximately minimized within the domain defined by the simple bounds. Global convergence of the sequence of generated iterates to a first-order stationary point for the original problem is established. Furthermore, possible numerical difficulties associated with barrier function methods are avoided as it is shown that a potentially troublesome penalty parameter is bounded away from zero. This paper is a companion to previous work of ours on augmented Lagrangian methods.
993.
Various models have been proposed in order to understand the near barrier heavy-ion fusion data. Amongst others the coupled
channel approach of Dasso and Landowne and the neutron flow picture of Stelson are two of the mechanisms which describe well
a large body of near barrier fusion data. From an analysis of16O induced fusion reaction around the barrier for various targets an attempt has been made to identify which out of the above
two mechanisms is more appropriate to explain these data. 相似文献
994.
Alexander A. Khassin Barbara L. Pietruszka Moritz Heintze Valentin N. Parmon 《Reaction Kinetics and Catalysis Letters》2004,82(1):131-137
Methane oxidation with air was studied over a Ni-containing catalyst in a dielectric barrier discharge (DBD) at temperatures
above 625 K. The DBD increases the methane conversion and shifts the process towards partial oxidation. This effect is related
to a catalyst heating by the discharge.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
995.
Rotational isomerism in enaminonitriles was studied using dynamic NMR spectroscopy and molecular modeling. It was found that the barrier to rotation about Cvinyl-NH bond was higher for enaminonitriles derived from aliphatic amines than that of enaminonitriles derived from aromatic amines. It was also found that the rotational isomerism about the Car-Cvinyl bond also exists in enaminonitriles. 相似文献
996.
997.
Ranga Subramanian Stewart E Novick Robert K Bohn 《Journal of Molecular Spectroscopy》2003,222(1):57-62
The microwave spectrum of 2-butynol, CH3CCCH2OH, has been investigated in the frequency range of 6-26.5 GHz. The spectra of the A and E torsional states were observed using Fourier transform microwave spectroscopy. Due to the presence of the cylindrically symmetric CC “spacer” between the methyl group and the rest of the molecule, the barrier to internal rotation, V3, is only 7 cm−1. One conformer of 2-butynol was observed and assigned. The spectrum was analyzed with the ρ-axis method using a very flexible Hamiltonian which gives a fit an order of magnitude better than that obtained with more standard code for internal rotation. The spectroscopic constants are: 23744.(18), 2093.429(1), 1966.358(1), and −400.34(2) MHz for A, B, C, and Dab; 0.48(1) kHz, −30.3(4) kHz, and 4.5(5) MHz for ΔJ, ΔJK, and ΔK; and 0.1406(6), 6.93(9) cm−1, −33.4(7) kHz, and 192.0(9) GHz for ρ, V3, LV, and F, respectively. The root mean squared error of the fit is 14 kHz. The angles between the internal rotor axis and principal axes are θa=12°, θb=78°, with θc held fixed at 90°. 相似文献
998.
In this work we consider a regionR in ℝ
n
given by a finite number of linear inequalities and having nonempty interior. We assume a pointx
o is given, which is close in certain norm to the analytic center ofR, and that a new linear inequality is added to those definingR. It is constructively shown how to obtain a perturbation of the right-hand side of this inequality such that the pointx
o is still close, in the same norm, to the analytic center of this perturbed polytope. This fact plays a central role in interior
point postoptimality techniques for linear programming involving methods of centers. 相似文献
999.
Bernd Kummer 《Mathematical Programming》1997,76(3):579-592
We investigate two homotopies that perturb Kojima’s system for describing critical points of a nonlinear optimization problem
in finite dimension. Each of them characterizes stationary points of a usual penalty and a new “barrier” function. The latter
is a continuous deformation of the objective, symmetric to the penalty from a formal point of view. Stationary points of these
functions appear as perturbed critical points and vice versa. This permits new interpretations of the related solution methods
and allows estimates of the solutions by using implicit function theorems for Lipschitzian equations. 相似文献
1000.