bluuebunny/crossref_metadata_2025_split huggingface dataset:
Short-term fire forecast based on air state gain recurrence and zero-order brown model
Authors: Pospelov Boris , Rybka Evgenіy , Meleshchenko Ruslan , Krainiukov Olekcii , Biryukov Igor , Butenko Tetiana , Yashchenko Oleksandr , Bezuhla Yuliia , Karpets Kostiantyn , Vasylchenko Ruslan 
Published: July 2021

Possibilities of parameterization of the zero-order Brown model for indoor air forecasting based on the current measure of air state gain recurrence are considered. The key to the zero-order parametric Brown forecasting model is the selection of the smoothing parameter, which characterizes forecast adaptability to the current air state gain recurrence measure. It is shown that for effective short-term indoor fire forecast, the Brown model parameter must be selected from the out-of-limit set defined by 1 and 2. The out-of-limit set for the Brown model parameter is an area of effective fire forecasting based on the measure of current indoor air state gain recurrence. Errors of fire forecast based on the parameterized zero-order Brown model in the case of the classical and out-of-limit sets of the model parameters are investigated using the example of ignition of various materials in a laboratory chamber. As quantitative indicators of forecast quality, the absolute and mean forecast errors exponentially smoothed with a parameter of 0.4 are investigated. It was found that for alcohol, the smoothed absolute and mean forecast errors for the classical smoothing parameter in the no-ignition interval do not exceed 20 %. At the same time, for the out-of-limit case, the indicated forecast errors are, on average, an order of magnitude smaller. Similar ratios for forecast errors remain in paper, wood and textile ignition. However, for the transition zone corresponding to the time of material ignition, a sharp decrease in the current measure of chamber air state gain recurrence is observed. It was found that for this zone, the smoothed absolute forecast error for alcohol is about 2 % if the model parameter is selected from the classical set. If the model parameter is selected from the out-of-limit set, the forecast error is about 0.2 %. The results generally demonstrate significant advantages of using the zero-order Brown parametric model with out-of-limit model parameters for indoor fire forecasting
Improving a model of object recognition in images based on a convolutional neural network
Authors: Knysh Bogdan , Kulyk Yaroslav 
Published: July 2021

This paper considers a model of object recognition in images using convolutional neural networks; the efficiency of the model-based process involving the training of deep layers in convolutional neural networks has been studied. There are objective difficulties associated with determining the optimal characteristics of neural networks, so there is an issue related to retraining a neural network. Eliminating the retraining by determining only the optimal number of epochs is insufficient since it does not provide high accuracy.
The requirements for the set of images for model training and verification have been defined. These requirements are better met by the INRIA image set (France).
GoogLeNet (USA) has been established to be a trained model that can perform object recognition on images but the object recognition reliability is insufficient. Therefore, it becomes necessary to improve the effectiveness of object recognition in images. It is advisable to use the GoogLeNet architecture to build a specialized model that, by changing the parameters and retraining some layers, could allow for better recognition of objects in images.
Ten models were trained using the following parameters: learning speed, the number of epochs, an optimization algorithm, the type of learning speed change, a gamma or power coefficient, a pre-trained model.
A convolutional neural network has been developed to improve the precision and efficiency of object recognition in images. The optimal neural network training parameters were determined: training speed, 0.000025; the number of epochs, 100; a power coefficient, 0.25, etc. A 3 % increase in precision was obtained, which makes it possible to assert the proper choice of the architecture for the developed network and the selection of its parameters. That allows this network to be used for practical tasks of object recognition in images.
Building a model and an algorithm for modeling the movement of people carrying goods when they are evacuated from premises
Authors: Pankratov Alexander , Komyak Valentina , Kyazim Kyazimov Tahir oglu , Komyak Vladimir , Tarasenko Olexandr , Antoshkin Oleksiy , Mishcheriakov Iurii , Dolhodush Mykhailo 
Published: July 2021

Evacuation is often the only way to save a person who is in a life-threatening situation. At present, evacuation software is used to simulate the movement of human flows, which does not always reflect the real processes of their movement. Therefore, it is a relevant task to build models for modeling the movement of human flows for different types of emergencies, different categories of human movement, and various spatial forms of their representation. Such a task arises when evacuating people from premises for various functional purposes.
During evacuation, people often carry some goods. When people move carrying some goods, their horizontal projection takes a more complex shape than an ellipse or circle considered in earlier studies. Moreover, in practice, there is often a task to model the movement of people taking into consideration the maximum permissible distances between them.
This paper reports the new quasi-phi functions of interaction between the ellipse and rectangle accounting for the maximum allowable distances between them. The proposed mathematical apparatus has made it possible to formalize the interaction between objects, thereby enabling the construction of a well-substantiated mathematical model, as well as the methods and algorithms for modeling the movement of people carrying some goods.
The possibility to simulate the movement of people with certain objects has shown taking into consideration the maximum permissible distances between them. A test example of the movement of people along four corridors was simulated, in each of which there were 28 people subsequently merging into one flow. Given the uniform distribution of three types of cargo: «backpacks», «suitcases», and «bags on wheels», the movement slowed down by about 4 %. When half of the evacuees had «bags on wheels» that can move away from people at arm’s length, the slowdown was about 6 %.
Formation of a complete stress-strain curve of concrete using digital image corellation
Authors: Blikharskyy Yaroslav , Pavliv Andrii 
Published: July 2021

This paper reports the development and verification of a new procedure for formation of a complete stress-strain curve of concrete with a downward region of strain by using a digital image correlation method. A new technique to build spectle patterns on the surface of concrete is described. That makes it possible to accurately enough reproduce the spectle patterns on the surface of concrete and perform a high-quality analysis of strains involving digital image correlation. The advantages of this research technique have been established when predicting the formation of internal cracks in concrete followed by their propagation. In addition, using the digital image correlation methodology makes it possible to obtain strains of the entire studied plane of the sample at each stage of loading. This procedure provides an opportunity to investigate a change in strains and the movement of individual points or areas when studying concrete surfaces. That is a relevant issue as it enables more detailed diagnostics of existing reinforced concrete structures. To check the accuracy of this procedure application, a mechanical gauge with an accuracy of 0.001 mm was additionally installed. 2 high-speed monochrome CCD cameras with different lenses were used in determining concrete strains involving the digital image correlation technique. The deformations were controlled with a period of time every 250 ms. The load was controlled by an additional third camera with a speed of 50 frames/second. The result of the experimental study is the formed full concrete destruction diagram with a downward region of strain. The deviation of the results of strains based on the mechanical gauge with an accuracy of 0.001 mm with a base of 200 mm from those acquired by the digital image correlation procedure was mainly up to 10 %, which confirms the reliability of the results. The results of this work allow a more accurate calculation of reinforced concrete structures in the practice of design, inspection, or reinforcement of existing structures
Comparative investigation of different types of nickel foam samples for application in supercapacitors and other electrochemical devices
Authors: Kovalenko Vadym , Kotok Valerii 
Published: July 2021

Nickel foam is widely used as a current lead/current collector and the basis of nickel hydroxide electrodes for various electrochemical devices – batteries, hybrid supercapacitors, devices for electrocatalytic oxidation of organic substances. The characteristics of commercial samples of nickel foam produced by Novomet-Perm (Russian Federation) obtained by electroless and then electrochemical nickel plating and Linyi Gelon LIB Co Ltd (China) obtained by electroless nickel plating were studied. The nature of passivity was determined by forming model samples of electrochemical and electroless nickel on a steel base. For the passive sample, activation was carried out by applying a layer of electrochemical nickel from an impact nickel plating solution. Activated, non-activated samples of nickel foam, as well as model samples, were studied by the methods of cyclic voltammetry and galvanostatic charge-discharge cycling in the supercapacitor mode. Comparative analysis of Chinese-made and Russian-made nickel foam samples showed significant passivity of the former – in cyclic voltammetry, the activity was 4.8 times lower, with galvanostatic charge-discharge cycling – 2.59 times lower. It was suggested that high passivity was determined by the fact that the sample consisted of Ni-P or Ni-B alloy. This assumption was proved by the method of natural simulation. The electrochemical activity of electroless nickel was 1.25 times lower than that of electrochemical nickel (according to cyclic voltammetry data) and 1.58 times lower (according to galvanostatic cycling data). For the first time, Chinese-made nickel foam (electroless nickel) was activated by applying a layer of electrochemical nickel from an impact nickel electrolyte. The high activation efficiency was shown as follows – on the cyclic curve, the specific current of the anodic peak increased 8.71 times, and with galvanostatic cycling, the increase in specific capacity was from 1.73 times (at i=120 mA/cm2) to 4.84 times (at i=20 mA/cm2)
Development of binary information compression methods based on the binomial numerical function
Authors: Kulyk Igor , Berezhna Olga , Novhorodtsev Anatoliy , Shevchenko Maryna 
Published: July 2021

The application of data compression methods is an effective means of improving the performance of information systems. At the same time, interest is aroused to the methods of compression without information loss which are distinguished by their versatility, low needs of costs during implementation, and the possibility of self-control.
In this regard, the application of binomial numbering systems is promising. The numerical function of the binomial numbering system is used for compression. It makes it possible to put sequences in one-to-one compliance with their numbers. In this case, the transition from binary combinations to binomial numbers is used as an intermediate stage.
During the study, theorems were formulated that indicate properties of compressing and restoring the mappings as well as the ways of their implementation. Models of compression processes were obtained on the basis of a numerical function, both for the case of compressible equilibrium combinations and the case when sequences of a general form are to be compressed. The compression models include coding steps based on binary binomials.
The study results show the effectiveness of applying the compression based on the binomial numerical function. A 1.02 times increase in speed of information transmission through a communication channel was observed in the worst case and 18.29 times in the best case depending on the number of ones in 128-bit equilibrium combinations. The proposed methods are advantageous due to their high compression ratio (from 1.01 to 16 times for general 128-bit sequences) and versatility: combinations are compressed in which the number of ones is 75 % of their total variation range. The developed methods ensure control of errors during conversions. They are undemanding to computation resources and feature low implementation costs.
Influence of sesame flour on physicochemical properties of sour milk drinks
Authors: Qin Xuanxuan , Samilyk Maryna , Luo Yanghe , Sokolenko Viktoriia 
Published: July 2021

This study aimed to investigate the technological properties of kefir fortified with defatted sesame flour (DSF). We have developed a recipe for producing kefir with the addition of 0, 2, 4, 6, 8 % DSF. The physicochemical parameters (pH, titratable acidity) and rheological properties (water-holding capacity, viscosity) of the samples within 28 days of storage were studied. All the samples were stored at a temperature of 4 °C. Nuclear magnetic resonance and chromatographic analysis were performed to determine the optimal shelf life of the product. It was found that fermentation ends on the seventh day of storage, while a low content of free water is observed. The recommended optimal storage time for kefir enriched with DSF is within 14 days. The introduction of 2 % DSF in kefir increases the content of vitamin E by three times (from 0.32 to 0.93 mg/100 g) and the content of proteins – by 1 % (from 3.36 to 4.3 %). The result showed that the pH value decreases with the introduction of DSF and is within the normal range during the entire storage period of the product (from 4.38 to 4.07). In this case, the total titratable acidity increases from 112.07 to 163.52 °T. An increase in viscosity (by 3 Pa∙s) and water-holding capacity (by almost 6 %) is observed with the addition of 2 % additive. Due to the high water-holding capacity and viscosity, dietary fiber content (up to 0.68 %), kefir supplemented with DSF showed high storage stability. The addition of 2 % DSF to kefir can increase the nutritional value and improve the structural stability of the product. DSF is a waste product with a bright prospect for use in the manufacture of fermented milk drinks
Design of systems for integrated processing of dairy raw materials in the cheese industry
Authors: Yatskov Mykola , Korchyk Natalia , Besediuk Volodymyr 
Published: July 2021

For the functioning of integrated systems for processing dairy raw materials in the cheesemaking industry, it is proposed to consider the basic concepts of synthesis of production systems. In order to implement the concept of waste minimization, it is proposed to separate the industrial wastewater into flows based on the concentration and values of the main parameters, as well as to protect the cheese whey from entering the water treatment facilities and direct it for disposal. The possibilities of implementing the concepts of deep raw materials processing into a target product have been analyzed, as well as the full utilization of raw and auxiliary materials. To this end, an experimental study was performed on the extraction of protein clots and adjusting the buffer capacity of infant dairy products using cheese whey. The study results indicate the insufficient effect of extracting the protein clot from whey (5–50 %) by combining the thermal and chemical processes. It was established that the redox conditions of the medium, in terms of the Eh indicator, can significantly affect the results, in close connection with the pH parameter and the estimated value of rH2. It was found that the optimal conditions for the functioning of lactic acid microflora in the production of soft cheeses can be ensured by adjusting the Eh indicator through the introduction of whey of pH=4.4–4.6 units, Eh≤–0.1 V. Whey is introduced at the stage of dairy raw material fermentation, which creates optimal conditions for the formation of a clot until reaching rH2 in the range from −5 to –7, and increases the product output by 1.5–7 %. The results of the experimental study indicate the high potential of using whey desalinated by ion exchange in order to reduce the buffer capacity in terms of acidity and adjust the redox conditions for infant milk mixtures until achieving rH2=15.5–15.9. The research reported in this paper could be the basis for the further development of systems for the integrated processing of dairy raw materials in the cheesemaking industry
Determination of adhesion of the coating deposited by arc spraying with pulsation of atomizing air flow
Authors: Zakharova Iryna 
Published: July 2021

During electric arc spraying, during the transfer of molten metal by air flow, there is a significant burnout of alloying elements with the formation of a large amount of oxides, which negatively affects the adhesion of the coating to the base. A solution to the problem of increasing the adhesion strength by using pulsation of the atomizing air flow is proposed. At the optimal frequency of the pulsed flow shut-off, the time of formation of liquid metal droplets at the ends of the electrodes coincides with the frequency of pulses of the spraying flow. As a result, the droplets acquire an optimal size, they are transported by an air flow with conservation of energy, a lower mass of oxygen and, as a consequence, a significant decrease in the oxidation of alloying elements in the sprayed material. The existing test methods of sprayed coatings for adhesion strength to the base are analyzed. The design of a modernized device for determining the adhesion strength is developed and described, which provides complex loading of the coating with a combination of tear-off and shear. The tests revealed a significant (up to two times) increase in the adhesion strength of aluminum, zinc-aluminum and steel (Sv08A) coatings applied with air pulsation. This is achieved by increasing the number of fusion zones of the coating particles between themselves and with the base. It is shown that the effect of the pulsation frequency on the adhesion strength changes along a curve with a maximum corresponding to a frequency of 70–80 Hz, regardless of the coating material. It has been established that the aluminum coating has an increased tendency to oxidation, as a result of which it is 15–20 % inferior to the zinc-aluminum coating in adhesion strength. The data obtained substantiate the use of the proposed spraying technology in production
Development of a solar element model using the method of fractal geometry theory
Authors: Budanov Pavlo , Kyrysov Ihor , Brovko Kostiantyn , Rudenko Dmytro , Vasiuchenko Pavlo , Nosyk Andrii 
Published: July 2021

It is shown that in the existing models of the solar cell, assumptions were made about the ideally smooth surface topography, which had a significant impact on the calculation of the output parameters. It is proposed to take into account the real working area of the receiving surface of the solar cell to improve the accuracy, linearity and stability of the current-voltage characteristics. A geometric model of the structure of the receiving surface of a solar cell has been developed, which describes and takes into account geometric changes in the structure of a semiconductor conducting layer, in the presence of damaging defects in the form of local inhomogeneities, micropores and macrocracks. It was found that the receiving surface with damaging defects is a porous inhomogeneous structure and has fractal properties: self-similarity, invariance, scalability. It is proposed to determine the real working area, to use the method of the theory of fractal geometry and, as an effective quantitative parameter for assessing the change in fractal structure, to choose the value of the fractal dimension. The obtained analytical expressions for the improved model establish the relationship between the output parameters and determine the degree of filling of the current-voltage characteristic for the output power and efficiency. The computational experiment showed that the real area can be much less than the geometric area of the topological relief and is quantitatively related to the change in fractal dimension in the range from 2.31 to 2.63. The obtained data on the real area, when solving analytical expressions for the solar cell model, play an important role in ensuring the stability and linearity of the current-voltage characteristic, increasing its accuracy up to 5 %.
Development of a method for selected financing of scientific and educational institutions through targeted capital investment in the development of innovative technologies
Authors: Levchenko Iaroslava , Dmytriieva Oksana , Shevchenko Inna , Britchenko Igor , Kruhlov Vitalii , Avanesova Nina , Kudriavtseva Oksana , Solodovnik Olesia 
Published: July 2021

The problem of supporting scientific and educational institutions is considered. A method of selective financing of scientific and educational institutions that create innovative technologies taking into account their investment in innovative developments is proposed. On the basis of statistical data on the indicators for assessing the activities of scientific and educational institutions and the indicator of the innovative potential of a scientific and educational institution from the production of innovations (PNn), their rating was calculated. The essence of PNn is to compare the indicators of the volumes of income of the special fund Dsfn and the volume of expenditures of the scientific and educational institution Vn.
In order to stimulate scientific and educational institutions to create innovative technologies, it was proposed to introduce targeted investments. The problem of quantifying the rate of premium on the basis of an integrated approach in terms of indicators of innovative potential from the production of innovations and the rating of a scientific and educational institution for 2 institutions (namely: K and H) has been solved. Institution K will receive a large increase, and institution N will receive a smaller increase, the value of which will be 56.23 % and 43.76 %, respectively. The results showed the independence of the indicator of the innovative potential of a scientific and educational institution from the production of innovations from the previous rating of a scientific and educational institution, or vice versa. The proposed methodology has been tested by an experimental method, targeted investments have been determined based on an integrated approach in terms of indicators of innovative potential and the rating of a scientific and educational institution.
This study is of practical interest to government authorities and grantors when allocating funds according to the vector of selective financing of scientific and educational institutions through targeted investments in the development of innovative technologies, and theoretically – to researchers dealing with issues of financial security, protectionism and public administration