Testing images independently of translations and linear deformations

This article considers the theory of construction of criteria that are independent of the motions of images, as as well rotations and linear deformations. A method is presented for construction of new types of criteria that have the following distinctive features: they make it easy to construct functionals for measurement of the characteristics of motion of standard images; the theory can easily be extended to the case of grey-scale and colored images; the criteria that are obtained are amenable to parallel computation; the proposed theory makes it easy to construct new criteria. Translated from Izmeritel’naya Tekhnika, No. 8, pp. 13–16, August, 1996.     

Crack growth and residual strength characteristics of two grades of glass-reinforced aluminium ‘Glare’

Crack growth and residual strength tests have been conducted on both Glare 3 and Glare 4 material. Results have been compared with those for 2024-T3 monolithic aluminium alloy showing improvements in fatigue life of up to 100 times and improvements in residual strengths of up to 40%. The potential weight savings and general structural performance improvements of the Glare material make it most attractive for future aerospace vehicle design, despite its current higher manufacturing costs.     

Effects of sex steroids on sensory and motor spinal mechanisms

The male copulatory pattern uses muscles in the penis for erection and penile insertion, the lower trunk for pelvic thrusting, and the sex accessory organs for seminal emission. Organization of the nuclei controlling penile muscles is achieved through cell growth, dendritic arborization, and synaptogenesis, actions dependent on androgen but not estrogen. Testosterone (T) and dihydrotestosterone (DHT) but not estradiol (E2), stimulate pelvic thrusting vigor by synchronizing discharge of motoneurons innervating pelvic muscles. Pelvic thrusting rhythmicity, regulated by spinal interneurons, is produced in female rabbits by E2 or T but not by DHT. Reflex contraction of the seminal vesicles, due to penile insertion, is facilitated by androgen presumably by its effect on preganglionic neurons of the hypogastric nerve, located in the dorsal commissural nucleus.     

Radiative-conductive heat transfer in a cylindrical monocrystal grown by the vertically oriented crystallization method

The steady-state two-dimensional problem of the radiative-conductive heat transfer in a cylindrical monocrystal is solved. The solution is obtained numerically by the time-independent technique. Convergence of the iteration process is achieved by including the relation between the intensity of the nonlinear source in the energy equation and the desired temperature field at a particular time step. An algorithm for calculating the intensity field and the nonlinear source is given. In calculating the first approximation of the temperature distribution, the method of moments is used. The results obtained are given.Moscow Institute of Railroad Transport Engineers, Moscow, Russia. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 66, No. 1, pp. 76–82, January, 1994.     

Anomalous photoemission threshold in high-T c oxide superconductor with Cs and K submonolayers

The photoemission threshold and photocurrent spectra were investigated for Bi₂Sr₂CaCu₂O₈ crystals with K or Cs submonolayer films. The different films of K or Cs were deposited on the Bi-O surface in the temperature range 80–250 K. We observed an appreciable (up to 0.3 eV) energy shift of the threshold and a strong modification of the photocurrent spectra for different temperatures and submonolayer coverages. The appropriate model of such a phenomena is based on a quasimetallic K or Cs clusters effect and additional 2D-polaronic effect.     

Purification and some properties of a xylanase from Aspergillus sydowii MG49

Aspergillus sydowii MG49 produces a 30-kDa exosplitting xylobiohydrolase during growth on xylan. A specific chemical modification and substrate protection analysis of purified xylanase provided evidence that tryptophan and carboxy and amino groups are present at the catalytic site of this enzyme. Thermal inactivation of the xylanase occurs because of irreversible polymolecular aggregation, which is slower in the presence of glycerol.     

Chemical control of superconducting properties of (Y,Ca)(Sr,Ba)2Cu2.7Ga0.3O7−δ

The partial substitution of Ga at the Cu(1) (chain) sites of the YBa₂Cu₃O₇ structure allows synthesis at ambient pressure of Ba-free analogs, e.g., YSr₂Cu_2.7Ga_0.3O_7?δ . Materials with this composition have been found to be nonsuperconducting, but superconductivity has been induced by one or more of the following methods: Ca substitutions at the Y site; Ba substitutions at the Sr site; annealing in high-pressure oxygen. The influence of these chemical manipulations onT _c has been monitored and all methods have been found to enhanceT _c . The electronic effects of Ba substitutions have been deduced indirectly using powder neutron diffraction, and such substitutions appear to result in a redistribution of hole density into the Cu(1) sites from the superconducting CuO₂ planes.     

A prototype 3D optically interconnected neural network

We report the implementation of a prototype three-dimensional (3D) optoelectronic neural network that combines free-space optical interconnects with silicon-VLSI-based optoelectronic circuits. The prototype system consists of a 16-node input, 4-neuron hidden, and a single-neuron output layer, where the denser input-to-hidden-layer connections are optical. The input layer uses PLZT light modulators to generate optical outputs which are distributed over an optoelectronic neural network chip through space-invariant holographic optical interconnects. Optical interconnections provide negligible fan-out delay and allow compact, purely on-chip electronic H-tree type fan-in structure. The small prototype system achieves a measured 8-bit electronic fan-in precision and a calculated maximum speed of 640 million interconnections per second. The system was tested using synaptic weights learned off system and was shown to distinguish any vertical line from any horizontal one in an image of 4×4 pixels. New, more efficient light detector and small-area analog synapse circuits and denser optoelectronic neuron layouts are proposed to scale up the system. A high-speed, feed-forward optoelectronic synapse implementation density of up to 10⁴/cm² seems feasible using new synapse design. A scaling analysis of the system shows that the optically interconnected neural network implementation can provide higher fan-in speed and lower power consumption characteristics than a purely electronic, crossbar-based neural network implementation