Vol 26, No 2 (2017)

In this paper we propose and realize an algorithm for exact calculation of partition function for planar graph models with binary variables. The complexity of the algorithm is O(N²) Experiments show good agreement with Onsager’s analytical solution for the two-dimensional Ising model of infinite size.

Development of performance principles of wireless sensor networks (WSN) and the methods of information routing in the networks, providing a capability of self-organized and automatic style of the WSN network work, is currently of substantial interest. The attraction of associated model of pulsed oscillator networks seems to be helpful for the design of adaptive synchronization-based information routing in the WSN. An oscillatory network model with pulsed oscillator dynamics and pulsed oscillator interaction is proposed. The initial version of information transfer in the WSN with the help of synchronization of an associated oscillatory network is discussed.

We analyzed the way to increase computational efficiency of video-based image recognition methods with matching of high dimensional feature vectors extracted by deep convolutional neural networks. We proposed an algorithm for approximate nearest neighbor search. At the first step, for a given video frame the algorithm verifies a reference image obtained when recognizing the previous frame. After that the frame is compared with a few number of reference images. Each next examined reference image is chosen so that to maximize conditional probability density of distances to the reference instances tested at previous steps. To decrease the required memory space we beforehand calculate only distances from all the images to small number of instances (pivots). When experimenting with either face photos from Labeled Faces in the Wild and PubFig83 datasets or with video data from YouTube Faces we showed that our algorithm allows accelerating the recognition procedure by 1.4–4 times comparing with known approximate nearest neighbor methods.

An optical sensor of an alternating electric field is described. The sensing element is a crystal quartz plate which reflects incident light by its front surface. Reflected light intensity is modulated by the tested electric field by means of changing the refractive index of the plate. Modulation of the reflection coefficient of the quartz by the tested electric field occurs due to the electro-optic effect. It is noted that the main advantage of the sensor working on the modulation of the reflected light is the ability to use opaque electro-optical media and thin films.

Mechanical action caused by the optical forces connected with the canonical momentum density associated with the local wave vector or classical spin angular momentum, the helicity dependent and the helicity independent forces determined by spin momenta of different nature open attractive prospects to use optical structures for manipulating with nanoobjects of different nature. The main finding of our study consists in demonstration of mechanical action of extraordinary transverse component of the spin angular momentum arising in an evanescent light wave due to the total internal reflection of linearly polarized probing beam with azimuth 45° at the interface ‘birefringent plate–air’.