256 research outputs found

    Implementation of 14 bits floating point numbers of calculating units for neural network hardware development

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    An important aspect of modern automation is machine learning. Specifically, neural networks are used for environment analysis and decision making based on available data. This article covers the most frequently performed operations on floating-point numbers in artificial neural networks. Also, a selection of the optimum value of the bit to 14-bit floating-point numbers for implementation on FPGAs was submitted based on the modern architecture of integrated circuits. The description of the floating-point multiplication (multiplier) algorithm was presented. In addition, features of the addition (adder) and subtraction (subtractor) operations were described in the article. Furthermore, operations for such variety of neural networks as a convolution network - mathematical comparison of a floating point ('less than' and 'greater than or equal') were presented. In conclusion, the comparison with calculating units of Atlera was made

    The use of plasma-based deposition with ion implantation technology to produce superhard molybdenum-based coatings in a mixed (C₂H₂+N₂) atmosphere

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    The influence of the pressure of a mixed gaseous atmosphere (80%C₂H₂+20%N₂) and the supply of a high-voltage negative potential in a pulsed form on the elemental and phase composition, structure and physico-mechanical characteristics of the vacuum-arc molybdenum-based coating

    Elastic waves push organic fluids from reservoir rock

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    Elastic waves have been observed to increase productivity of oil wells, although the reason for the vibratory mobilization of the residual organic fluids has remained unclear. Residual oil is entrapped as ganglia in pore constrictions because of resisting capillary forces. An external pressure gradient exceeding an ‘‘unplugging’’ threshold is needed to carry the ganglia through. The vibrations help overcome this resistance by adding an oscillatory inertial forcing to the external gradient; when the vibratory forcing acts along the gradient and the threshold is exceeded, instant ‘‘unplugging’’ occurs. The mobilization effect is proportional to the amplitude and inversely proportional to the frequency of vibrations. We observe this dependence in a laboratory experiment, in which residual saturation is created in a glass micromodel, and mobilization of the dyed organic ganglia is monitored using digital photography.We also directly demonstrate the release of an entrapped ganglion by vibrations in a computational fluid-dynamics simulation

    Properties of superhard nanostructured coatings Ti-Hf-Si-N

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    New superhard coatings based on Ti-Hf-Si-N featuring high physical and mechanical properties were fabricated. We employed a vacuum-arc source with HF stimulation and a cathode sintered from Ti-Hf-Si. Nitrides were fabricated using atomic nitrogen (N) or a mixture of Ar/N, which were leaked-in a chamber at various pressures and applied to a substrate potentials. RBS, SIMS, GT-MS, SEM with EDXS, XRD, and nanoindentation were employed as analyzing methods of chemical and phase composition of thin films. We also tested tribological and corrosion properties. The resulting coating was a two-phase, nanostructured nc-(Ti, Hf)N and α-Si3N4. Sizes of substitution solid solution nanograins changed from 3.8 to 6.5 nm, and an interface thickness surrounding α-Si3N4 varied from 1.2 to 1.8 nm. Coatings hardness, which was measured by nanoindentation was from 42.7 GPa to 48.6 GPa, and an elastic modulus was E = (450 to 515) GPa. The films stoichiometry was defined for various deposition conditions. It was found that in samples with superhard coatings of 42.7 to 48.6GPa hardness and lower roughness in comparison with other series of samples, friction coefficient was equal to 0.2, and its value did not change over all depth (thickness) of coatings. A film adhesion to a substrate was essentially high and reached 25MPa. В работе получены новые сверхтвердые покрытия на основе Ti-Hf-Si-N с высокими физико-механическими свойствами. В процессе синтеза методом вакуумно-дугового осаждения с применением ВЧ напряжения распылялся цельнолитой катод Ti-Hf-Si. Нитриды формировались в среде атомарного азота (N) или в смеси Ar/N, которые напускались в камеру при различных давлениях. Химический и фазовый составы тонких пленок анализировался методами RBS, SIMS, GT-MS, SEM с EDXS, РСА, а твердость определялась наноиндентированием. Исследовались трибологические и коррозионные свойства покрытий. Полученные покрытия являются двухфазными наноструктурированными nс-(Ti, Hf)N и α-Si3N4. Размеры нанозерен твердого раствора варьировались от 3,8 до 6,5 нм, а толщина окружающей оболочки α-Si3N4 менялась от 1,2 до 1,8 нм. Твердость покрытий H составляла 42,7 48,6 ГПа, а модуль упругости Е принимал значения от 450 ГПа до 515 ГПа. Определена стехиометрия пленок при различных условиях осаждения. Установлено, что в образцах сверхтвердых покрытий с твердостью 42,7 48.6 ГПа наблюдалась более низкая шероховатость по сравнению с другими образцами, коэффициент трения составлял 0,2, и его значение не изменялось по всей глубине (толщине) покрытия. Адгезия пленки к подложке достигла 25 МПа. У роботі отримані нові надтверді покриття на основі Ti-Hf-Sі-N з високими фізико-механічними властивостями. У процесі синтезу методом вакуумно-дугового осадження із застосуванням ВЧ напруги розпорошувався суцільнолитий катод Tі-Hf-Sі. Нітриди формувалися у середовищі атомарного азоту (N) або у суміші Ar/N, які напускалися у камеру при різних тисках. Хімічний і фазовий склади тонких плівок аналізувалися методами RBS, SІMS, GT-MS, SEM з EDXS, РСА, а твердість визначалася наноіндентуванням. Досліджувалися трибологічні та корозійні властивості покриттів. Отримані покриття є двофазними наноструктурованими nс-(Tі, Hf)N і -Sі3N4. Розміри нанозерен твердого розчину варіювалися від 3,8 до 6,5 нм, а товщина навколишньої оболонки -Sі3N4 змінювалася від 1,2 до 1,8 нм. Твердість покриттів H становила 42,7 48,6 ГПа, а модуль пружності Е приймав значення від 450 ГПа до 515 ГПа. Визначено стехіометрію плівок при різних умовах осадження. Встановлено, що у зразках надтвердих покриттів із твердістю 42,7 48.6 ГПа спостерігалася нижча шорсткість у порівнянні з іншими зразками, коефіцієнт тертя становив 0,2, і його значення не змінювалося за глибиною (товщиною) покриття. Адгезія плівки до підкладки досягла 25 МПа

    Implementation of 14 bits floating point numbers of calculating units for neural network hardware development

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    An important aspect of modern automation is machine learning. Specifically, neural networks are used for environment analysis and decision making based on available data. This article covers the most frequently performed operations on floating-point numbers in artificial neural networks. Also, a selection of the optimum value of the bit to 14-bit floating-point numbers for implementation on FPGAs was submitted based on the modern architecture of integrated circuits. The description of the floating-point multiplication (multiplier) algorithm was presented. In addition, features of the addition (adder) and subtraction (subtractor) operations were described in the article. Furthermore, operations for such variety of neural networks as a convolution network - mathematical comparison of a floating point ('less than' and 'greater than or equal') were presented. In conclusion, the comparison with calculating units of Atlera was made

    Nanostructured multielement (TiHfZrNbVTa)N coatings before and after implantation of N+ ions (1018 cm 2 ): Their structure and mechanical properties

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    Multielement high entropy alloy (HEA) nitride (TiHfZrNbVTa)N coatings were deposited by vacuum arc and their structural and mechanical stability after implantation of high doses of N+ ions, 1018 cm 2 , were investigated. The crystal structure and phase composition were characterized by X-ray diffraction (XRD) and Transmission Electron Microscopy, while depth-resolved nanoindentation tests were used to determine the evolution of hardness and elastic modulus along the implantation depth. XRD patterns show that coatings exhibit a main phase with fcc structure, which preferred orientation varies from (1 1 1) to (2 0 0), depending on the deposition conditions. First-principles calculations reveal that the presence of Nb atoms could favor the formation of solid solution with fcc structure in multielement HEA nitride. TEM results showed that amorphous and nanostructured phases were formed in the implanted coating sub-surface layer (100 nm depth). Concentration of nitrogen reached 90 at% in the near-surface layer after implantation, and decreased at higher depth. Nanohardness of the as-deposited coatings varied from 27 to 38 GPa depending on the deposition conditions. Ion implantation led to a significant decrease of the nanohardness to 12 GPa in the implanted region, while it reaches 24 GPa at larger depths. However, the H/E ratio is P0.1 in the sub-surface layer due to N+ implantation, which is expected to have beneficial effect on the wear properties

    Influence of the Bilayer Thickness of Nanostructured Multilayer MoN/CrN Coating on Its Microstructure, Hardness, and Elemental Composition

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    Multilayer nanostructured coatings consisting of alternating MoN and CrN layers were obtained by vacuum cathode evaporation under various conditions of deposition. The transition from micron sizes of bilayers to the nanometer scale in the coatings under investigation leads to an increase in hardness from 15 to 35.5 GPa (with a layer thickness of about 35 nm). At the same time, when the number of bilayers in the coat- ing decreases, the average Vickers hardness increases from 1267 HV0.05 to 3307 HV0.05. An increase in the value of the potential supplied to the substrate from –20 to –150 V leads to the formation of growth textures in coating layers with the [100] axis, and to an increase in the intensity of reflections with increasing bilayer thickness. Elemental analysis carried out with the help of Rutherford backscattering, secondary ion mass spectrometry and energy dispersion spectra showed a good separation of the MoN and CrN layers near the surface of the coatings

    Extensive Chaos in the Nikolaevskii Model

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    We carry out a systematic study of a novel type of chaos at onset ("soft-mode turbulence") based on numerical integration of the simplest one dimensional model. The chaos is characterized by a smooth interplay of different spatial scales, with defect generation being unimportant. The Lyapunov exponents are calculated for several system sizes for fixed values of the control parameter ϵ\epsilon. The Lyapunov dimension and the Kolmogorov-Sinai entropy are calculated and both shown to exhibit extensive and microextensive scaling. The distribution functional is shown to satisfy Gaussian statistics at small wavenumbers and small frequency.Comment: 4 pages (including 5 figures) LaTeX file. Submitted to Phys. Rev. Let

    Investigation of nanoscale TiN/MoN multilayered systems, fabricated using Arc evaporation

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    Using the vacuum-arc evaporation method we fabricated periodic multilayered TiN/MoN structures with different bilayer periods λ ranging from 8 to 100 nm. We found that molybdenum nitride and titanium nitride layers grown on steel show local partial epitaxy and columnar growth across interfaces. A molybdenum-titanium carbide interlayer was evidenced between the substrate and the multilayer. Molybdenum nitride and titanium nitride layers contain small (5÷30 nm) grains and are well crystallized with (100) preferred orientation. They were identified as stoichiometric fcc TiN and cubic γ-M2N. Non-cubic molybdenum nitride phases were also detected. The hardness of the obtained structures achieved great values and maximal hardness was 31÷41.8 GPa for the multilayered structure with a 8 nm period. Hardness of the obtained coatings is 25÷45% higher in comparison with the initial single-layer nitride coatings, plasticity index of multilayered structure is 0.075

    DEVELOPMENT OF A GROUP OF MOBILE ROBOTS FOR CONDUCTING COMPREHENSIVE RESEARCH OF DANGEROUS WAVE CHARACTERISTICS IN COASTAL ZONES

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    New methods and approaches for carrying out comprehensive measurements of hazardous waves (tsunami, storm surges) and background wave climate with telemetrically related group of ground, surface and underwater based robots are discussed. The design and equipment list of the ground robot are considered. It includes three various types of movers, an add-on for the installation of devices on the mobile platform and the hardware part. Ground robot was tested in 2016 on the coast of Sakhalin Island, cape Svobodny. Based on test results there were made conclusions on the possibility of increasing mobility of the ground robot and expanding its use. Specially designed underwater robot collects data using a video inspection system and a hydrostatic wave recorder with a string sensor. It has the ability to adjust the position of the center of gravity to increase stability when driving on steep slopes of the seabed. The surface robot was designed for conducting detailed bathymetry measurements of investigated water areas by means of a multi-beam echo sounder. Underwater and surface-based robots were tested in July 2017 on Sakhalin Island. Both robotic systems were merged into the united local network. The results of their operation were obtained to verify the data from measuring systems of the ground robot. In 2018, it is planned to conduct a series of tests involving the three robots and merging them into a local network to manage and process data in real-time
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