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1.
This study presents a variational-perturbation approach for the three-dimensional stress analysis around a curvilinear cutout in composite laminates. The solution is based on a composite expansion and assumed stress finite element methods. Stress field solutions for angleply and cross-ply laminates containing an elliptical hole have been presented. The effects of the ellipse aspect ratio and the fiber orientation on the interlaminar shear stress magnitude have been investigated. A failure criterion based on the interlaminar distortional energy function has been suggested. According to this criterion, it was found that, for angle-ply laminates containing an elliptical hole, a delamination failure initiation occurs at a point along the perpendicular to the direction of loading. 相似文献
2.
Monika Pinchas 《Signal, Image and Video Processing》2011,5(1):29-37
Recently, a Maximum Entropy (MaxEnt) algorithm and its derivation called WNEW algorithm were presented by the same author.
It was shown that the MaxEnt and WNEW algorithm have improved equalization performance compared with Godard’s, reduced constellation
algorithm and the sign reduced constellation algorithm. In this paper, a new equalization method is proposed for the 16QAM
and 64QAM input constellation based on the WNEW algorithm which is extended with some polynomials of the equalized output
and optimized with the mean square error criteria. According to simulation results, the new equalization method leads to over
15 dB advantage in the residual Intersymbol Interference compared to the results presented by Godard, 10 dB advantage compared
with the WNEW algorithm and 5 dB advantage compared with the MaxEnt algorithm. 相似文献
3.
Axel E. Jungk Moshe Luwisch Shraga Pinchas Gerhard M. J. Schmidt 《Israel journal of chemistry》1977,16(4):308-310
It is shown that the specific pathway of a complex photochemical reaction in the solid state is governed by the molecular conformation and its retention, and by the molecular packing. 2′-Nitrochalcone and those of its derivatives which are isomorphous with it display the s-trans conformation in the solid state and yield indigos upon irradiation. However, this conformation is not sufficient to ensure photoreactivity: thus the s-trans-4-bromo-derivative does not yield indigo. The same derivative in the s-cis conformation (in a second crystal form) has a crystal structure similar to that of the parent compound, and also does not yield indigo. 相似文献
4.
5.
The infrared and Raman spectra of normal and 89.5 atom % 18O-labelled sodium sulphate have been measured both for the solid salts and for their aqueous solutions. All the fundamentals of S16O2?4 and S18O2?4 have been observed. The observed isotopic frequency ratios of these fundamentals agree excellently with theory. 相似文献
6.
Monika Pinchas 《Signal, Image and Video Processing》2013,7(1):67-74
In this paper, I propose for the noisy, real, and two independent quadrature carrier case, an approximated closed-form expression for the achievable minimum mean square error (MSE) performance obtained by blind equalizers where the error that is fed into the adaptive mechanism which updates the equalizer’s taps can be expressed as a polynomial function of the equalized output of order three like in Godard’s algorithm. The proposed closed-form expression for the achievable MSE is based on the step-size parameter, on the equalizer’s tap length, on the channel power, on the signal to noise ratio (SNR), on the nature of the chosen equalizer, and on the input signal statistics. Since the channel power is measurable or can be calculated if the channel coefficients are given, there is no need anymore to carry out any simulation with various step-size parameters, different values for the signal to noise ratio (SNR) and equalizer’s tap length for a given equalization method, and input signal statistics in order to find the MSE performance in the convergence state. 相似文献
7.
Monika Pinchas 《Signal, Image and Video Processing》2012,6(2):325-340
In this paper, I propose for the noiseless, real and two independent quadrature carrier case some approximated conditions
on the step-size parameter, on the equalizer’s tap length and on the channel power, related to the nature of the chosen equalizer
and input signal statistics, for which a blind equalizer will not converge anymore. These conditions are valid for type of
blind equalizers where the error that is fed into the adaptive mechanism that updates the equalizer’s taps can be expressed
as a polynomial function of the equalized output of order three like in Godard’s algorithm. Since the channel power is measurable
or can be calculated if the channel coefficients are given, there is no need anymore to carry out any simulation with various
step-size parameters and equalizer’s tap length for a given equalization method and input signal statistics in order to find
the maximum step-size parameter for which the equalizer still converges. 相似文献
8.
Shraga Shoval Yehiel Rosenfeld & Ronie Navon 《Computer-Aided Civil and Infrastructure Engineering》2001,16(3):180-187
Palletizing concrete pavement blocks is a labor-intensive task that requires high levels of workmanship, skill, and concentration. This article proposes an automatic system in which palettes with required design patterns are assembled automatically off-site and then shipped to the construction site. The efficiency of the assembly process can be improved by incorporating automatic equipment consisting of assembly heads and feeders. An algorithm was developed to determine the optimal layout of the feeders (of different blocks) around the palette and the exact assembly sequence of each layer of blocks. Experimental results show that the algorithm is near optimal and that the solutions provided by it reduce palletizing cycle time for various patterns and sizes of concrete block by 20 to 30 percent. 相似文献
9.
The laminar boundary layer equations for the compressible flow due to the finite difference in rotation and temperature rates are solved for the case of uniform suction through the disk. The effects of viscous dissipation on the incompressible flow are taken into account for any rotation rate, whereas for a compressible fluid they are considered only for a disk rotating in a stationary fluid. For the general case, the governing equations are solved numerically using a standard finite element scheme. Series solutions are developed for those cases where the suction effect is dominant. Based on the above analytical and numerical solutions, a new asymptotic finite element scheme is presented. By using this scheme one can significantly improve the pointwise accuracy of the standard finite element scheme. 相似文献
10.
S. Pinchas 《Israel journal of chemistry》1969,7(1):5-10
The infrared absorption of crystalline powders and D2O solutions of normal and 84.5 atom % 18O-labelled sodium arsenate as well as normal and 83.3 atom % 18O-labelled sodium permanganate was measured in the 780–980 cm?1 region. The ν1 and ν3 fundamentals of the aqueous As18O43? ion appear at 834(sh) and 866(s) cm?1 while the respective As18O43? values are 808 and 822 cm?1 These as well as other data are shown to indicate that the water molecules which hydrate this ion are attached to its As atom. The ν3 frequency of the aqueous Mn18O4? ion is observed at 917 cm?1 and that of hydrated Mn18O4? at 878 cm?1. 相似文献