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201.
Ivan Nunes da Silva Wagner Caradori do AmaralLucia Valeria de Arruda 《Applied Mathematical Modelling》2007
This paper presents an efficient approach based on recurrent neural network for solving nonlinear optimization. More specifically, a modified Hopfield network is developed and its internal parameters are computed using the valid subspace technique. These parameters guarantee the convergence of the network to the equilibrium points that represent an optimal feasible solution. The main advantage of the developed network is that it treats optimization and constraint terms in different stages with no interference with each other. Moreover, the proposed approach does not require specification of penalty and weighting parameters for its initialization. A study of the modified Hopfield model is also developed to analyze its stability and convergence. Simulation results are provided to demonstrate the performance of the proposed neural network. 相似文献
202.
O. Životský K. Postava L. Kraus M. Foldyna J. Pištora 《Journal of magnetism and magnetic materials》2006
In this paper we investigate the surface magnetic properties of as-quenched (AQ) CoFeCrBSi ribbons prepared by planar flow casting method with using magneto-optic Kerr effect (MOKE). Measured hysteresis loops in longitudinal and transversal configurations enable us to obtain the information of ribbons surface magnetic properties. Moreover, we suggest new magneto-optic method, which is based on measurements of magneto-optical effects depending on DC current flowing through the ribbon. Experimental data of AQ ribbons are then compared with the model, which describes the influence of incidence angle on magneto-optical angles. 相似文献
203.
O. P. Galkin V. S. Gostev O. E. Popov L. V. Shvachko R. F. Shvachko 《Acoustical Physics》2006,52(3):252-258
The experimental data on the sound field structure, which were obtained by emitting a continuous pseudonoise signal (a midfrequency of 3.2 kHz) in a two-channel oceanic waveguide, are compared with the calculations performed by the wave program with allowance for the fine structure of the sound speed inhomogeneities. A considerable increase in the intensity of the sound field with a definite angular spectrum is observed in the upper channel in the first shadow zone, and, in the experiment, the increase begins nearer to the sound source than predicted by the wave and ray calculations for a smooth sound speed profile. These features of the field structure are explained by the illumination of the shadow zone by the regular scattering of signals from highly anisotropic fine-structure inhomogeneities of the sound speed profile, which are clearly pronounced in the region of the given oceanic experiment. 相似文献
204.
Detection of hepatocarcinoma in rats by integration of the fluorescence spectrum: Experimental model
J. C. Marcassa J. Ferreira S. Zucoloto O. de Castro e Silva Jr. L. G. Marcassa V. S. Bagnato 《Laser Physics》2006,16(5):827-832
The incorporation of spectroscopic techniques into diagnostic procedures may greatly improve the chances for precise diagnostics. One promising technique is fluorescence spectroscopy, which has recently been used to detect many different types of diseases. In this work, we use laser-induced tissue fluorescence to detect hepatocarcinoma in rats using excitation light at wavelengths of 443 and 532 nm. Hepatocarcinoma was induced chemically in Wistar rats. The collected fluorescence spectrum ranges from the excitation wavelength up to 850 nm. A mathematical procedure carried out on the spectrum determines a figure of merit value, which allows the detection of hepatocarcinoma. The figure of merit involves a procedure which evaluates the ratio between the backscattered excitation wavelength and the broad emission fluorescence band. We demonstrate that a normalization allowed by integration of the fluorescence spectra is a simple operation that may allow the detection of hepatocarcinoma. 相似文献
205.
THE FIRST EXPERIMENT OF A THz GYROTRON WITH A PULSE MAGNET 总被引:1,自引:0,他引:1
T. Idehara H. Tsuchiya O. Watanabe La Agusu S. Mitsudo 《International Journal of Infrared and Millimeter Waves》2006,27(3):319-331
A THz gyrotron with a pulse magnet has been designed, constructed and operated in FIR FU. It is developed as one of high frequency
gyrotrons included in Gyrotron FU Series. The gyrotron has already achieved the first experimental result for high frequency
operations whose radiation frequency exceeds 1 THz. In this paper, the design detail and the operation test results for sub-terahertz
to terahertz range are described. The second harmonic operation is confirmed experimentally at the expected frequency of 1.005
THz due to TE6,11 cavity mode at the magnetic field intensity of 19.0 T. 相似文献
206.
207.
V. M. Kuz’kin O. Yu. Lavrova S. A. Pereselkov V. G. Petnikov K. D. Sabinin 《Acoustical Physics》2006,52(1):65-76
The space-time spectral characteristics of the field of background internal waves (IW) are obtained for two oceanic shelf
regions (the Atlantic shelf of the United States and the Kamchatka shelf) and analyzed. Within the framework of a numerical
experiment, it is shown that the observed anisotropy of the IW field may considerably affect the low-frequency sound fluctuations
in the aforementioned regions and, in particular, may change the interference invariant of the sound field. 相似文献
208.
Using a density-functional method that employs linear combinations of atomic orbitals as basis sets, nonlocal norm-conserving pseudopotentials and the generalized gradient approximation for exchange and correlation, we found that at 0 K the atoms of an Fe monolayer on the Ni (111) surface occupy hcp rather than fcc sites, in keeping with previous predictions made using the ab initio all-electron full-potential linearized augmented plane wave method with the local spin density approximation. 相似文献
209.
We have studied the characteristic features of carbazole phosphorescence quenching by benzophenone in toluene at 77 K. We
have shown that the decrease in the relative phosphorescence intensity for carbazole (energy donor) by a greater factor than
we see for the relative change in its decay time is due to the fact that a change in the phosphorescence decay time occurs
only for carbazole molecules participating in triplet-triplet energy transfer, while the substantial decrease in the phosphorescence
intensity for carbazole with no change in the phosphorescence decay time is connected with quenching of its singlet states.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 4, pp. 554–556, July–August, 2006. 相似文献
210.
O. A. Vasilyev 《JETP Letters》2002,75(3):162-166
The Harris-Aharony criterion for a static model predicts that if a specific heat exponent α>0, then this model does not exhibit self-averaging. In the two-dimensional percolation model, the index α= ?1/2. This means that, in accordance with the Harris-Aharony criterion, the model can exhibit self-averaging properties. We study numerically the relative variances R M and R χ for the probability M of a site belonging to the “infinite” (maximum) cluster and for the mean finite-cluster size χ. It was shown that two-dimensional site-bond percolation on the square lattice, where the bonds play the role of the impurity and the sites play the role of the statistical ensemble over which the averaging is performed, exhibits self-averaging properties. 相似文献