FPGA Implementation of Convolutional Neural Networks with Fixed-Point Calculations

Neural network-based methods for image processing are becoming widely used in practical applications. Modern neural networks are computationally expensive and require specialized hardware, such as graphics processing units. Since such hardware is not always available in real life applications, there is a compelling need for the design of neural networks for mobile devices. Mobile neural networks typically have reduced number of parameters and require a relatively small number of arithmetic operations. However, they usually still are executed at the software level and use floating-point calculations. The use of mobile networks without further optimization may not provide sufficient performance when high processing speed is required, for example, in real-time video processing (30 frames per second). In this study, we suggest optimizations to speed up computations in order to efficiently use already trained neural networks on a mobile device. Specifically, we propose an approach for speeding up neural networks by moving computation from software to hardware and by using fixed-point calculations instead of floating-point. We propose a number of methods for neural network architecture design to improve the performance with fixed-point calculations. We also show an example of how existing datasets can be modified and adapted for the recognition task in hand. Finally, we present the design and the implementation of a floating-point gate array-based device to solve the practical problem of real-time handwritten digit classification from mobile camera video feed

TEACHING METHODS IN THE UNIVERSITY COURSE “BIOPHYSICS”

The article presents some methods and results of experimental teaching biophysics at Pskov State University (Russian Federation). The goal of any university is to train highly qualified specialists. To achieve this aim, the authors suggest following interdisciplinary approach to the educational process. Some topics of the lecture presentations, video clips and demonstration educational experiments as well as examples of computer modelling of biophysical processes are considered. Subjects of the real and virtual biophysical, biological and medical experimental tasks for students working in an educational university physical laboratory are discussed

OPTICAL PROPERTIES OF LASER-COLOURING MARKED STAINLESS STEEL

Laser colour-marking method often displace conventional marking techniques. Complicated technology of laser-induced periodic surface structure creation on stainless steel samples allows changing their surface morphology and optical properties, which were studied in this work by atomic force microscopy (AFM), laser scanning microscopy, reflectance spectroscopy and ellipsometry. Reflectance spectra of the samples demonstrate reflectance maxima correlate with the visible colours of the samples and with the extrema in the non-monotonic spectral dependences of the derivative of real part of complex dielectric permittivity extracted from the ellipsometric data. Thus, the most intensive light scattering takes place when the real part of complex dielectric permittivity falls down quickly with changing wavelength. We did not observe any “azimuth anisotropy” in our optical measurements at constant incidence angle: the spectra were the same independently of the light incidence plane orientation (parallel or perpendicular to the previous laser light spot scanning direction). We suppose that this selective resonance-like light scattering is due to the sample surface inhomogeneity, which is the result of previous laser treatment. This assumption agrees with estimations based on laser microscope and AFM images as well as with predictions of Mie theory. Thus, the colours of the samples under study are due to the light scattering by randomly distributed surface species with different sizes.

Coulomb Correlations and Magnetic Anisotropy in ordered L10L1_0 CoPt and FePt alloys

We present results of the magneto-crystalline anisotropy energy (MAE) calculations for chemically ordered $L1_0$ CoPt and FePt alloys taking into account the effects of strong electronic correlations and spin-orbit coupling. The local spin density + Hubbard U approximation (LSDA+U) is shown to provide a consistent picture of the magnetic ground state properties when intra-atomic Coulomb correlations are included for both 3$d$ and 5$d$ elements. Our results demonstrate significant and complex contribution of correlation effects to large MAE of these material.Comment: revised version; 4 pages, 2 figure

Determination of the shelterbelts influence on the average productivity of agrophytocenoses based on geostatistical analysis of spatial data and the NDVI

Shelterbelts effect positively on the elements of the microclimate, the water regime of soils, the agronomic properties of the soil, soil fertility in the agricultural landscape. The assessment of the influence of the density of shelterbelts on the overall productivity of arable land is poorly studied. In this study, the methodology for assessing of such impact with using GIS technologies is suggested. We propose to use the Normalized Vegetation Index (NDVI), as a standardized index showing the relative biomass of vegetation, averaged for each working area within the studied region for working plots of arable land with an area of more than 25 hectares in the Belgorod oblast. Paired correlation analysis between the density of shelterbelts and arable land productivity showed the weak relationship (R2= 0.124), however, the classification of the density of shelterbelts with the interval of 0.5 km/km2 allowed us to reveal the linear regression dependence y = 0.0059x + 0.5195 (R2 = 0.989) of arable land productivity from the density of shelterbelts. Taking into account that many abiotic factors can affect the yield, we additionally proposed to carry out typing to identify areas of the same type in terms of the relief of the earth’s surface, climatic conditions and productivity. To do this, the spatial clustering (K-means algorithm) was proposed to use. It was revealed that the productivity of agrophytocenoses increases by 10% with the increasing of the density of shelterbelts by 2 times with an average slope steepness of up to 2°. In physical terms, the yield of winter wheat will increase by 0.28 t/ha. Soil-protective crop rotations are an additional factor in increasing the value of the NDVI index on slopes more than 2°

Problems of Organizing Critical Thinking Training for University Students

The paper aims to determine the factors that hinder forming and developing critical thinking of students and ways to overcome them in higher education. First, it is a problem of low motivation and a low level of self-regulation in critical thinking training. These problems reduce the effectiveness of all those methods and techniques for forming critical thinking that teachers use. We propose applying differentiated learning (multilevel learning) as one of the most effective ways to solve the problem of organizing critical thinking training. Moreover, we consider that at the beginning of training, it is necessary to determine the personal qualities of students, such as purposefulness, self-discipline, perseverance, tolerance, academic motivation, and self-regulation of cognitive activity. During the learning process, it is necessary to use multilevel tasks and exercises to cover all categories of students. This is because these tasks are based on some volitional qualities of the personality and motivation for learning. This approach is systemic and makes it possible to achieve high efficiency in teaching critical thinking