721 research outputs found
Mathematical description of stress-strain state of trunnion of ball mill taking into account temperature field
The article considers the trunnion of a ball mill in the framework of theory of elasticity, which is subjected to an uneven thermal impact due to the heating of the load. Equations describing the radial displacement of the point inside the trunnion of a ball mill are obtained. The equations describing the movement of trunnion points of the ball mill are derive
Modeling of Injection Parameters for Diesel Engine Injector Nozzles with the Additional Precision Guiding Interface
AbstractPerfection of output parameters of diesel engines is considered as a result of the rail-pressure increase and modernization of nozzle tribosystems represented at high (up to 300 MPa) values of the fuel pressure. The nozzle with the modified design and additional (bottom) precision guiding interface is used and hydrodynamic parameters of injection are analyzed. The computational fluid-dynamic (CFD) modeling for estimation of hydrodynamic parameters of the fuel flow and force distribution in the “needle – nozzle body” system is used. The results of the injection modeling and contact parameters for the modified design of nozzle precision interfaces are established and discussed. The ways of increasing the stability of needle position in the nozzle body with perfection of parameters of fuel injection are presented
Periodic chiral magnetic domains in single-crystal nickel nanowires
We report on experimental and computational investigations of the domain
structure of ~0.2 x 0.2 x 8 {\mu}m single-crystal Ni nanowires (NWs). The Ni
NWs were grown by a thermal chemical vapor deposition technique that results in
highly-oriented single-crystal structures on amorphous SiOx coated Si
substrates. Magnetoresistance measurements of the Ni NWs suggest the average
magnetization points largely off the NW long axis at zero field. X-ray
photoemission electron microscopy images show a well-defined periodic
magnetization pattern along the surface of the nanowires with a period of
{\lambda} = 250 nm. Finite element micromagnetic simulations reveal that an
oscillatory magnetization configuration with a period closely matching
experimental observation ({\lambda} = 240 nm) is obtainable at remanence. This
magnetization configuration involves a periodic array of alternating chirality
vortex domains distributed along the length of the NW. Vortex formation is
attributable to the cubic anisotropy of the single crystal Ni NW system and its
reduced structural dimensions. The periodic alternating chirality vortex state
is a topologically protected metastable state, analogous to an array of
360{\deg} domain walls in a thin strip. Simulations show that other remanent
states are also possible, depending on the field history. Effects of material
properties and strain on the vortex pattern are investigated. It is shown that
at reduced cubic anisotropy vortices are no longer stable, while negative
uniaxial anisotropy and magnetoelastic effects in the presence of compressive
biaxial strain contribute to vortex formation.Comment: 15 pages, 11 figure
The modular structure of the adaptive machine learning system
Machine learning system based on the modular structure can tune to particular subject area flexibly and form the optimal individual educational trajector
Multi-critera selection of a corporate system by using paired comparison analysis
The paper presents the results of comparing foreign corporate information systems (CISs) obtained by using the classical analytic hierarchy process (AHP). The eight most common corporate information systems of international standards were analyzed, there were determined some classes of criteria which are vital when selecting a system, and for each criterion 3-4 most suitable systems were identifie
Algorithm for individual learning content formation in automated machine learning system
The study describes the algorithms used in the formation of individual learning content which can be used in machine learning. The algorithm for generating educational content based on the input test procedure, thereby reducing the number of elementary units of knowledge in the educational conten
Decision support system for the expert assessment of social risks
The study is devoted to the development of decision support systems in the expert assessment of social risk
System analysis of properties of coatings and indicators of the process of plasma and electrolytic oxidations quality
The article is devoted to solution of the problem of systematization of the parameters for the model that associate the properties of the obtained coatings with the qualitative properties of coatings on the basis of the method of plasma-electrolytic oxidation (PEO) of valve metals. Nowadays for the synthesis of the required parameters of technological processing regimes (electrical regimes, concentrations of the components of the electrolyte) in the process of coatings’ forming various measured parameters of the coating are use
Formal methods of analysis and synthesis for decisions options during corporate information system development
The article presents a generalized approach to decision making in the process of application development based on cyclically repeating actions, including the synthesis of solution options and their analysis. They considered the basic methods of analysis and synthesis used in decision-making process on the design of corporate information systems (CIS). The description of the proposed generalized semantic model is given on
the example of component interaction of the Integrated complex of high-level development tools and the functioning environment of corporate-level information systems (Platform). They analyzed the process of CIS IT infrastructure on the basis of the Platform and the specific steps of making a management decision for this
exampl
- …