This article describes the experience in the
development and implementation of the method of
qualimetric evaluation of contractors based on the
application of the methodology of multicriteria rating.
The introduction of the qualimetric assessment into the
practice of management activities allows reducing the
risks of selecting unreliable contractors, to increase the
efficiency of construction and investment companies,
and their competitiveness in the construction services
market
The article formulates and solves the task of discrete
control in the thermophilic stage of the composting
process. It is shown, that considering the relay control
entity to maintain specified process conditions requires
the organization of the sliding mode. We have solved the
problem of minimizing the temperature deviation of the
substrate from the set values and the deviation of the
oxygen concentration in the gas phase of the bioreactor
from the specified values. The article shows an algorithm
to compute the discrete control of the composting
process in the thermophilic stage. This article was
prepared in the framework of the scientific project 16-
48-230441 a(R) "Mathematical modeling of the
processes occurring in the automated installation for
year-round production of organic fertilizers in the
conditions of the Krasnodar region", financed by RFBR
and the administration of the Krasnodar region
The intense rhythm of people's lives in many countries has led to the need to develop and produce «fast food» products. They include dry breakfasts of a porous macrostructure in the form of rods, bars, and flakes, made from cereals, legumes, potatoes and dried fruits. Over the past 10 years, ready-to-eat foods that do not require heat treatment have become popular, the range of breakfast cereals has significantly increased, air grains, pads with filling, asterisks and rings have appeared. The global trend of consumption of slowly digestible carbohydrates predominates. Corn flakes and blown grain began to be used as supplements to soup instead of toast, served for tea and coffee. However, the problem of making and marketing specialized dry breakfasts has not yet been fully solved. The aim of the research is to expand the range of specialized dry breakfasts for people with high physical and mental loads. The tasks of modernizing technology and equipment for the production of dry breakfasts were solved. The methods of preparation for extrusion of easily oxidized in the air raw nuts were developed. Formulations of dry breakfasts for people with high physical and mental loads were developed. The objects of the research are analysis of existing technological schemes, grain, fruit and nut raw materials. We used classical methods of research to determine the composition of proteins, lipids and carbohydrates, as well as modern instrumental methods for assessing the qualitative composition of raw materials, semi-finished products and finished products. The research results include the modernization of technology and equipment for the production of breakfast cereals. Formulations of ready-made breakfast cereals with the addition of cereals, dry fruits and nuts have been developed, in order to improve the quality characteristics and nutritional value of the extrudates. The proposed technology and developed recipes are promising for introduction into production
The article describes the modeling process of the
heating system operation of a livestock-breeding
complex. It presents graphs reflecting the influence of
technological parameters of heat supply system of
cattle-breeding complex with a catalytic combustion
device on the parameters of energy efficiency of the
system and the parameters characterizing the stability
of the temperature conditions in the livestock sector
In this work, we have analyzed the multiple
literary sources and summarized the material
regarding beet dietary fibers. Their composition,
physicochemical, physicomechanical and
hygrothermal properties were studied. The study of
the particle-size distribution showed that the
content of the insoluble fraction exceeded the
content of the soluble fractions in all the samples.
The use of the secondary products of processing of
the plant raw material is also critical; they allow
improving the preventive properties of products
and enriching them with dietary fibers, protein, and
mineral elements. The properties and quality of the
raw material are, to the large extent, determined by
and depend upon its granulometric composition,
that is, upon the size of particles that compose this
object. The authors determined the granulometric
composition of the studied nutritional supplements.
It was found out that the use of the combination of
the impacts together with the abrading impact led
to the intensification of the process, a decrease in
the milling time and the uniformity of the obtained
granulometric composition. The choice of the
vertical mill as milling equipment in combination
with the metal balls added to it to increase the
efficiency of milling and uniformity of the
granulometric composition of beetroot fibers was
proved experimentally
In agricultural production, the direction of introduction
of renewable energy for power consumers remote from
the external electrical network is relevant. Here,
prospects are revealed in front of the solar PV stations.
One of the main functional units of solar power is
inverters that convert the DC voltage of the solar
panels into alternating current. The article describes
the advantages and disadvantages of the main methods
of voltage regulation of the autonomous inverters of
solar photovoltaic power plants. We have proposed
new structural designs of autonomous voltage
inverters, described their advantages, features of
design and operation for voltage stabilization. We
suggest stand-alone inverters designed using high
frequency link, which will significantly improve mass
and dimensions parameters of the converter. Due to the
use of single-phase transformer with a rotating
magnetic field in stand-alone inverters, we improve the
efficiency of the converter and the reliability of the
work. Patents of the Russian Federation confirmed the
novelty of technical solutions of the considered
schemes of autonomous voltage inverters. Structural
schematics of the voltage regulators considered in the
article, as well as features of their work, will allow to
increase efficiency of preliminary works on
development of autonomous voltage inverters with
improved operational and technical characteristics for
solar photovoltaic power plants
At the nodes of the various machines, we use plain bimetal bearings: a steel base - antifriction cladding layer. Bimetal bearings have increased performance. One of the ways of making such bearings is the way of centrifugal bimetallization with heating of the independent electric arc. An important requirement of this technology is a uniform heating of the workpiece along the entire length until the formation of a continuous layer of the molten cladding material. The process of bimetallization require temperature control, since within the movement of the electric arc, low heat or high heat are possible due to heat dissipation from the ends of the workpiece in the installation and from the outer surface of the workpiece to the environment. A viable option the temperature control of the heat process of bimetallization for industrial conditions is to control the temperature of the outer surface of the steel base. It is necessary to solve the heat problem of the relationship between the temperature on the surface of the workpiece with the temperature on the boundary layers. For this purpose the numerical solution of the mathematical model of the thermal process, which includes the heat transmitting equation of Fourier and heat transfer at the ends of the sleeve according to Newton's law. The equivalent coefficients of heat transfer are obtained based on calculated and experimental thermograms. This is a time-consuming work. To minimize the time of fixing the boundary value problem of the thermal process of bimetallization, in this work we present the preliminary modeling based on the analytical solution of the thermal task of bi-metallization
With the aim of improving the productivity and performance of the sunflower seed separation process in the air-sieve seed-cleaning machine called MVU-1500 its multivariate analysis was carried out. The main indicators of the seed heap separation process were determined according to the feeding of the seed heap onto the sieve of the lattice. The indicators are as follows: completeness of the j-th components screening, the j-th components content in the sieve path, the completeness of their discharge and their content in the discharge from the sieve tier. Having adopted the hypothesis of a possible increase in the efficiency of the separation process in the air-sieve grain cleaning machine, we analyzed the delivery patterns of seed heap components into the pneumatic channel with the aim of optimizing the process. For a more complete assessment of the process indicators under consideration, basic patterns of movement of various components in the sieve-tier lattice were estimated. It was taken into account that in modern designs of air-sieve grain cleaning machines seeds are fed into the pneumatic channel from the sieves. When the width of the lattice is equal to one, the density of the j-th component of the seed heap is constant along the length of each sieve in the stack of sieves and the separation coefficient is constant along the length of the sieve, the expression received estimates the average speed of movement in the first sieve-tier lattice in the steady process of separation. There was evaluated the statistical significance of differences of the j-th component average speed movement on the second sieve- lattice by Student's t-criterion, which showed that they belong to the same sample of random variables and do not have statistically significant differences. Therefore, we can obtain the following velocity values of the heap of sunflower seed movement in the sieve-tier lattice: fragments of stems velocity is 0.0518 m/s; milled seeds velocity is 0.0381 m/s; velocity of sunflower seeds less than 3.2 and 3.2-3.6 mm thick is 0.0835 m/s, velocity of sunflower seeds of 3.6-4.0 mm thick is 0.0453 m/s, that of more than 4.0 mm thick is 0.0410 m/s
The main task in the analysis of time series is the
reconstruction of the dynamical system that generated
this series. To illustrate the nature of the behavior of a
dynamic system described by a nonstationary time
series, a «phase portrait» method is proposed. An
acceptable description of the phase space of a
dynamical system can be obtained if we take instead
of real variables of the system delay vectors
composed of the values of the series at consecutive
moments of time. Restoration in a given class of a
system of differential or difference equations is
performed based on the scalar time series of the
observed process. In order to eliminate the
measurement error and accurately represent the
position of the object in the current, future, or any of
the past moments, it is proposed to apply the Kalman
filter using the known mathematical model of object
dynamics
This article is devoted to the problem of network
attacks recognition, which is essential for providing
network security. A research of neural network
efficiency has been held. Such metaeuristic
algorithms as genetic algorithm, gray wolf
algorithm and firefly algorithm have been applied
for the neural network learning. The algorithms’
fundamentals have been described. Multilayer
perseptrone with sigmoid activation function has
been selected for the task of network attack
presence check. Various configurations of the
neural network have been tested in order to find the
optimal number of layers and neurons per layer,
which ensure the least error. Learning has been
performed by minimization of the average squared
error between the network’s output and its target
value with the help of the listed algorithms. Genetic
algorithm requires accurate parameter picking in
case of any network’s architecture alteration.
Moreover, it is not as fast as firefly and gray wolf
algorithms. Gray wolf algorithm appears to be the
most effective one. However, it loses its efficiency
if the number of layers is increased. Firefly
algorithm proves to be the most universal one.
Although it is less effective than gray wolf
algorithm, it provides the most exact output even if
the network’s structure is changed