bluuebunny/crossref_metadata_2025 huggingface dataset:
Short term temperature fluctuations affect embryonic and larval development of yellow perch (Perca flavescens)
Authors: Sepulveda Villet Osvaldo J
Published: November 2021

Early life stages of fishes are critical stages due to their importance in enhancing recruitment. Given the high mortality through the embryonic and larval stages, managers have started investigating factors that impact these stages. Environmental factors, such as water temperature, have been found to play a larger role in early life survival. Climate change predications will be more apparent in northern temperate systems like the Great Lakes. Yellow perch Perca flavescens are an important sport fish in the region whose populations have been declining since the 1980s. Yellow perch recruitment is highly erratic due to the species dependence on spring water temperatures. With warming waters occurring earlier in the seasons, it is unsure how wild yellow perch will adapt. The objective of this study was to determine how variations in temperature regimes during the egg incubation period would impact embryonic and larval development in yellow perch. Four different temperature treatments were used in this study: steady temperature at 16°C, a gradient starting at 12°C increasing by 1-2°C every 3-4 days, a heat shock on day six of 20°C for 16 hours to mimic a heat wave event, and finally, a cold shock on day six of 10°C temperatures for 16 hours to mimic a cold snap event. The results of this study confirm that water temperatures severely impact embryonic development and incubation periods of yellow perch, having a significant impact on the percent of failed larvae at the end of the incubation period (P= 0.0005), with the cold shock affecting the lowest percent of failed larvae (0.8%) while the steady treatment had the highest percent (22.9%). Temperature treatment did have a significant impact on the time it took for larvae to successfully hatch out (P<0.001), but no significant effect on observed mortality and estimated mortality (P= 0.96), percent of surviving larvae (P=0.35), or average growth rate of larvae (P=0.16).This study reveals that yellow perch are better adapted to withstand acute cold shifts in water temperature than acute warming events. Climate change could potentially hinder an already struggling Lake Michigan yellow perch population.
Gender is not a relevant matter in habitat selection of the longsnout seahorse Hippocampus reidi Ginsburg, 1933 (Teleostei: Syngnathidae)
Authors: Freret-Meurer Natalie V
Published: November 2021

Habitat selection in certain species may vary according to context and environmental conditions. Sexual differences regarding habitat use have been reported for several species, such as mammals, birds and fish, and have been explained by protection and food resource contexts. This issue is not well studied in seahorses, but it may provide useful data for the management of threatened species. The Longsnout Seahorse has recently been considered near threatened, but many gaps regarding its habitat use are still noted. Seahorses display a particular breeding characteristic, in which males carry the embryos inside a breeding pouch, therefore leading to supposed careful selection of breeding habitats, avoiding predation risks and choosing habitats with high prey availability. In this context, this study aimed to verify differences in habitat selection between male and female Longsnout Seahorse Hippocampus reidi specimens along the coast of the state of Rio de Janeiro. This study took place at 11 sites along the Rio de Janeiro coastline, in southeastern Brazil. Random belt transects (20x5m) were assessed, searching for seahorses and their holdfasts. Random quadrats (50x50cm) divided into 100 cells/each were placed along the transects and benthic cover was counted, in order to establish substrate availability. Results suggested that males select fewer substrate types than females, but no statistical difference was detected. Both male and female H. reidi specimens select mostly Sargassum vulgare as a frequent habitat. The strong association of H. reidi to these seaweed beds suggests vulnerability concerning the degradation of this habitat.
When being pioneers in embracing technological innovation in not enough, an exploration into French Connection
Authors: Majid Jamal
Published: November 2021

The onset of the pandemic and it impact on business has not only warranted business thinking of new, interesting and innovating ways in which to engage with consumer. However, has also warranted fashion brands to re-establish their core values and traits that originally made them successful. This conversation of re-evaluation of the core factors of success is now more important ever if key players in the fashion industry are seeking to engage in evolutionary transformation via the assistance of technology in order to survive and indeed retain their mantel of being vanguards for societal change during and in the aftermath of the pandemic. The necessity for business to engage with technology to entice Millennials and Generation Z more successfully is also of paramount concern. This is warranted in order to provide a counter voice to the negative viewpoints, which exist in relation to the perception of the fashion industry being exploitive and un-sustainable. The incumbents in the fashion industry reaction to the emergent change that the pandemic has created, necessitates all industries to make actionable plans now more than ever, in conjunction with understanding that change is an inevitable ongoing reality of all business and emergent radical changes may be what the business world will encounter in the future. However, it is important to acknowledge the resurgence in the fashion industry must be managed and navigated in a holistic manner. This warrants the inclusion all parts of an organisation working in conjunction with designers towards to the attainment of the same goals. Thus, unity of purpose is now more acute that ever by using French Connection as a case study the author proposes a model within which to embark upon the change process. The time for change is now and if organisation views this with opportunity in a positive manner, the results could prove to be favourable.
Marginal umbilical cord insertions in a bipartite placenta responsible for placenta abruption: a case report
Authors: Nkwabong Elie , Borassi Sylvie
Published: November 2021

Hemorrhage is one of the major causes of maternal death. Main causes of APH are placenta previa, placenta abruption and uterine rupture. Rare causes of placenta abruption include marginal and velamentous umbilical cord insertions. We hereby present a case of placenta abruption due to marginal umbilical cord insertions occurring on a bipartite placenta. A 40-year-old nulliparous African woman, 35 weeks pregnant consulted for dark red pervaginal bleeding, which occurred recently. Past history was unremarkable. Her pregnancy was well followed up. A recent ultrasound scan revealed a fundal inserted placenta. Physical examination revealed a fundal height of 37 cm, no uterine activity, normal fetal heart tones and a blood-stained vulva. Our diagnosis was a mild placenta abruption. An obstetrical ultrasound carried out revealed a normal pregnancy and a retroplacental blood clot of 11mm. A safe baby was born through an emergency cesarean section which revealed a normally inserted bipartite placenta with a 10% placenta detachment located on one placenta half and two cords inserted marginally. The postoperative period was uneventful and she was discharged five days after cesarean section. This case report shows that marginal cord insertion, which can lead to placenta abruption, can be also observed on a bipartite placenta.
Analysis of mechanical strength of weight fraction variation sugar palm fiber as polypropylene-elastomer matrix reinforcement of hybrid composite
Authors: Nitya Santhiarsa I Gusti Ngurah , Praharsini I Gusti Ayu Agung , Alit Suryawati I Gusti Agung , Pratikto Pratikto
Published: November 2021

Currently, the availability of polypropylene, elastomer and sugar palm fiber (Arenga pinnata) is very abundant, which has a good impact on the potential for the development of new composite materials that have good properties and characteristics. Composites are generally a new material composed of two or more different materials with the aim of producing a new material that has better properties than the constituent material. In this study, polypropylene (PP) plastic and elastomer were used as a composite matrix reinforced with sugar palm fiber (Arenga pinnata). The purpose of this study was to determine the value of tensile strength, impact strength, and bending strength of composites with a weight fraction of 20 % (80:20), 30 % (70:30), and 40 % (60:40). Based on the results of the research on hybrid composites of polypropylene and fiber-reinforced elastomers, composites with a weight fraction of 20 % (80:20) got the lowest tensile strength value of 1.153 MPa, while composites with a weight fraction of 40 % (60:40) obtained the highest tensile strength value of 2.613 MPa. Composites with a weight fraction of 20 % (80:20) got the lowest tensile strain value of 0.0049 and the highest tensile strain value of 0.0067 was found in composites with a weight fraction of 40 % (60:40). For the impact strength, the 40 % (40:60) weight fraction composite got the lowest value of 45248.234 kJ/mm2, while the 20 % (80:20) weight fraction composite got the highest impact strength of 17649.97 kJ/mm2. For bending strength results, the composite with a weight fraction of 20 % (80:20) obtained the lowest bending strength of 1.7778 MPa, while the composite with a weight fraction of 30 % (70:30) obtained the highest bending strength of 4.8867 MPa. The highest bending strain was found in the composite with a weight fraction of 20 % (80:20), which was 0.0207.
Development of a hyperparameter optimization method for recommendatory models based on matrix factorization
Authors: Nechaev Alexander , Meltsov Vasily , Strabykin Dmitry
Published: November 2021

Many advanced recommendatory models are implemented using matrix factorization algorithms. Experiments show that the quality of their performance depends significantly on the selected hyperparameters. Analysis of the effectiveness of using various methods for solving this problem of optimizing hyperparameters was made. It has shown that the use of classical Bayesian optimization which treats the model as a «black box» remains the standard solution. However, the models based on matrix factorization have a number of characteristic features. Their use makes it possible to introduce changes in the optimization process leading to a decrease in the time required to find the sought points without losing quality.
Modification of the Gaussian process core which is used as a surrogate model for the loss function when performing the Bayesian optimization was proposed. The described modification at first iterations increases the variance of the values predicted by the Gaussian process over a given region of the hyperparameter space. In some cases, this makes it possible to obtain more information about the real form of the investigated loss function in less time.
Experiments were carried out using well-known data sets for recommendatory systems. Total optimization time when applying the modification was reduced by 16 % (or 263 seconds) at best and remained the same at worst (less than 1-second difference). In this case, the expected error of the recommendatory model did not change (the absolute difference in values is two orders of magnitude lower than the value of error reduction in the optimization process). Thus, the use of the proposed modification contributes to finding a better set of hyperparameters in less time without loss of quality
Development of recommendations on the hierarchy of activities regarding the implementation of the BRC standard in relation to the safety of packaging using the AHP method
Authors: Kawecka Agnieszka , Cholewa-Wójcik Agnieszka , Sikora Tadeusz
Published: November 2021

The British Retail Consortium Global Standard for Food Safety enjoys great popularity among food industry companies, the number of companies with the certified standard is rising every year. The packaging used for food packaging has a very large impact on the safety and quality of the packaged food. The purpose of the study was to indicate the requirements of the standard in relation to packaging, which should be implemented firstly by enterprises of the food industry. In the research part, the AHP analysis was conducted on the basis of the experts' recommendations. Decision matrixes for every criterion: hazard analysis concerning packaging, purchase procedure, packaging acceptance procedure were developed. A decision matrix for the main criterion as a result of criteria decision matrix was developed, global decision hierarchy was also developed. Research clearly showed that the most important activity (among the proposed) is hazard analysis, with a 0.517 weighted sum value. In many of the detailed requirements of the standard, hazard analysis and risk assessment (0.333 weighted sum value) are the basis for many activities, including establishing a purchasing procedure (0.163 weighted sum value), accepting packaging (0.297 weighted sum value), or many others. The relevance of this study is the identification of the hierarchy of importance of activities performed within the framework of ensuring the quality and safety of food packaging. A reasonable approach is presented. The AHP method allows indicating the sequence of activities during the implementation of the BRC standard, as evidenced by pilot studies carried out on the basis of procedures related to the safety of packaging. The standard sets up requirements for packaging in the form of packaging management procedure, in which it should be stated how the site operates with packaging. Moreover, there are requirements concerning hazard analysis in relation to packaging
Devising a concept of integrated design and modeling of aircraft
Authors: Grebenikov Oleksandr , Humennyi Andrii , Dveirin Oleksandr , Soboliev Oleksandr , Buival Lilia
Published: November 2021

The analysis of aircraft design methods reported here has revealed that building a competitive aircraft necessitates devising a scientifically based concept of integrated aircraft design employing CAD/CAM/CAE/PLM software suites.
A generalized concept of integrated design and three-dimensional computer modeling of aircraft involving the CAD/CAM/CAE/PLM systems has been developed. Based on the proposed concept, the principles of integrated design of aircraft were devised. The features of designing the training and training-combat aircraft, transport-category aircraft, light civilian aircraft have been described.
A method for determining the take-off weight, design parameters, and formation of the general appearance of aircraft has been improved. The method is intended to form the appearance of the aircraft at the stages of preliminary design, the purpose of which is reduced to determining the permissible version of the aircraft project. The project must meet the predefined requirements and restrictions in the selected aircraft scheme and the assigned set of parameters that characterize its airframe and power plant.
A method of parametric modeling of aircraft has been improved, which includes the stages of creating a master geometry of the aircraft and a model of space distribution. Parametric models of master geometry and models of space distribution, training and training-combat aircraft, transport-category aircraft, light civilian aircraft have been constructed.
Methods of integrated design of aircraft main units have been devised and theoretically substantiated. Parametric models of master geometry of the wing for a training aircraft, the wings, appendage, and fuselage of a light civilian aircraft were built, taking into consideration the design features of aircraft units of various categories
Nutritional value of a dry soluble gerodietetic product for enteral nutrition
Authors: Antiushko Dmytro , Bozhko Tetiiana , Shapovalova Nataliia , Fil Mariia , Brovenko Tеtіana , Tolok Galina , Antonenko Artem , Gyrka Olga , Bodak Mykhailo , Bezruchko Lubomyr
Published: November 2021

Results of conducted experimental studies of the nutritional value of the developed dry soluble gerodietetic product for enteral nutrition are presented. Content of proteins, fats, and carbohydrates (22.8, 11.8, and 56.4 g/100 g of dry product, respectively) was determined and calorific value (422.8 kcal/100 g) and mass fraction of macronutrients in it were calculated (21.5/25.1/53.4 respectively). Their compliance with recommendations of specialists to satisfy nutritional needs of older people, in particular, those with increased physical and neuro-emotional loads, certain dysfunctions, somatic diseases, injuries, and recovering after them were analyzed and determined. Qualitative and quantitative amino acid composition of the product was studied, the rate of its essential and conditionally essential amino acids was calculated on its basis, coefficient of discrepancy of its amino acid composition was found (17.14 %) and biological value of the protein component (82.86 %) was calculated. Experimental studies of the vitamin value of the developed product and its elemental structure were carried out. The dry product has a fairly high content of vitamins (especially ascorbic acid, retinol, thiamine, pyridoxine) and mineral elements (potassium, calcium, phosphorus, magnesium, iron, iodine, selenium). Based on the obtained results, an average level of satisfaction of the daily need for the studied vitamins (on average within 14–41 %), mineral elements (mostly by 10–25 %) from consumption of 100 g of dry product in the prepared liquid state was calculated. The conducted studies have shown high nutritional value, in particular calorific and biological value of the product and conformity of its composition to the needs of the older age groups
Development of a method of structural-parametric assessment of the object state
Authors: Mahdi Qasim Abbood , Zhyvotovskyi Ruslan , Kravchenko Serhii , Borysov Ihor , Orlov Oleksandr , Panchenko Ihor , Zhyvylo Yevhen , Kupchyn Artem , Koltovskov Dmytro , Boholii Serhii
Published: November 2021

A method of structural and parametric assessment of the object state has been developed. The essence of the method is to provide an analysis of the current state of the object under analysis. The key difference of the developed method is the use of advanced procedures for processing undefined initial data, selection, crossover, mutation, formation of the initial population, advanced procedure for training artificial neural networks and rounding coordinates. The use of the method of structural-parametric assessment of the object state allows increasing the efficiency of object state assessment. An objective and complete analysis is achieved using an advanced algorithm of evolution strategies. The essence of the training procedure is the training of synaptic weights of the artificial neural network, the type and parameters of the membership function, the architecture of individual elements and the architecture of the artificial neural network as a whole. An example of using the proposed method in assessing the operational situation of the troops (forces) grouping is given. The developed method is 30–35 % more efficient in terms of the fitness of the obtained solution compared to the conventional algorithm of evolution strategies. Also, the proposed method is 20–25 % better than the modified algorithms of evolution strategies due to the use of additional improved procedures according to the criterion of fitness of the obtained solution. The proposed method can be used in decision support systems of automated control systems (artillery units, special-purpose geographic information systems). It can also be used in DSS for aviation and air defense ACS, DSS for logistics ACS of the Armed Forces of Ukraine
Analysis of loss on single-phase dry transformers with non-linear load
Authors: Khristiana Harrij Mukti , Soeparman Sudjito , Wahyudi Slamet , Hasanah Rini Nur
Published: November 2021

The paper studies power losses in transformers due to non-linear loads. The research aims to analyze the power loss in a single-phase dry transformer under a non-linear load. The research uses an SW43W Power supply type, FlukeView Power Quality Analyzer as a DC or AC power supply on the primary side of the transformer. The non-linear load is connected to the secondary side. The loading test of the dry transformer was carried out at non-linear loads. The load variations used 0 %; 12.5 %; 25 %; 37.5 %; 50 %; 62.5 %; 75 %; 87.5 % and 100 %, as well as variations in the THD value by adjusting the ignition angle (α). The non-linear loads used are Half-Wave Rectifier and Controlled Half-Wave Rectifier with resistive loads with variations in THD values. The results showed that the transformer losses comprised Pno load and Pload. The operation of the transformer with constant input voltage and frequency with THDv<5 % resulted in a constant Pno load value at all load values. The greater the percentage of the load, the higher the load. The increase in THD because of non-linear load will increase the load on the transformer. The value of the derating factor is obtained by connecting the increase in losses (∆PLosses), which is influenced by THD and the increase in temperature T(°C) in dry transformers. When the transformer is loaded with a non-linear load, the derating factor<1. THD and derating factor form a linear relationship, when THD increases, the derating factor value decreases. Linear load on the transformer causes a decrease in its capacity, but if it gets a non-linear load with THD=39.1 %, it can withstand a load of 84.294 %, besides the increase in total harmonic distortion will increase losses and reduce transformer capacity
Comparative analysis of means to control the thermal regime of a cooling thermoelement while minimizing the set of basic parameters
Authors: Zaykov Vladimir , Mescheryakov Vladimir , Zhuravlov Yurii
Published: November 2021

This paper reports a comparative analysis of the thermal regime control means while minimizing a set of basic parameters in various combinations with the indicators of reliability and dynamics of the functioning of a single-stage thermoelectric cooler. The connection has been established between the optimal relative operating current corresponding to the minimum of the set on the relative temperature difference and heat sink capacity of the radiator. The results of calculating the main parameters, reliability indicators, time of entering the stationary mode of operation for various current modes of operation at a fixed temperature difference, thermal load at different geometry of the branches of thermoelements are given. A comparative analysis of the main parameters, indicators of the reliability and operational dynamics of a single-stage cooler under various characteristic current modes of operation has been carried out. Minimizing the set of basic parameters in conjunction with the reliability indicators and operational dynamics of the cooling thermoelement provides a decrease in the refrigeration coefficient up to 40 % compared to the maximum cooling capacity mode, as well as the optimal heat sink capacity of the radiator, the amount of energy expended, the time of entering the stationary mode, the relative intensity of failures. The analysis of the influence of the temperature difference at a predefined thermal load on the relative operating current, the time it takes for the cooler to enter the stationary thermal regime, the heat sink capacity of the radiator, the relative intensity of failures has been performed. The devised method of optimal control over the thermal regime of a single-stage thermoelectric cooler based on minimizing the set of basic parameters makes it possible to search for and select compromise solutions, taking into consideration the weight of each of the limiting factors
Characteristics of raw water sources and analysis of the optimal model of the mixing process with parameter design in clean water pump installations
Authors: Tamjidillah Mastiadi , Ramadhan Muhammad Nizar , Setiawan Muhammad Farouk , Iberahim Jerry
Published: November 2021

The quality characteristics of raw water sources in the regional integrated drinking water supply system (SPAM) of Banjarbakula were investigated and found to maintain the supply of drinking water quantity and quality in accordance with drinking water standards. The optimum model for the mixing process of raw water and poly aluminum chloride (PAC) and pump stroke for the input of water sources from rivers to obtain a composition setting that is in accordance with the raw water sources of each region in the region was selected and determined. So the optimum parameter setting model between alum water, raw water and pump stroke for each raw water source is known and is regionally integrated as a result of a comprehensive study. The integration of Taguchi parameter design and response surface can complement each other and become two methods that go hand in hand in the process of optimizing clean water products. Parameter design provides a very practical optimization step, the basis for this formation refers to the factorial fractional experimental design. However, the absence of statistical assumptions that follow the stages of analysis makes this method widely chosen by researchers and practitioners. With the experimental design of the raw water mixing process, turbidity such as 5 lt/sec, 10 lt/sec, 15 lt/sec, 20 lt/sec and 25 lt/sec and % PAC concentration 5 ppm, 10 ppm, 15 ppm, 20 ppm and 25 ppm with a pump installation stroke of 5 %, 10 %, 15 %, 20 % and 25 % were used. In the process of adding PAC, always pay attention and observe the behavior of the attractive force of the floating particles (flock). The particles were then subjected to SEM (scanning electron microscopy) to determine the dimensions of the flock grains deposited
Analysis of one class of optimal control problems for distributed-parameter systems
Authors: Mamtiyev Kamil , Aliyeva Tarana , Rzayeva Ulviyya
Published: November 2021

In the paper, the method of straight lines approximately solves one class of optimal control problems for systems, the behavior of which is described by a nonlinear equation of parabolic type and a set of ordinary differential equations. Control is carried out using distributed and lumped parameters. Distributed control is included in the partial differential equation, and lumped controls are contained both in the boundary conditions and in the right-hand side of the ordinary differential equation. The convergence of the solutions of the approximating boundary value problem to the solution of the original one is proved when the step of the grid of straight lines tends to zero, and on the basis of this fact, the convergence of the approximate solution of the approximating optimal problem with respect to the functional is established.
A constructive scheme for constructing an optimal control by a minimizing sequence of controls is proposed. The control of the process in the approximate solution of a class of optimization problems is carried out on the basis of the Pontryagin maximum principle using the method of straight lines. For the numerical solution of the problem, a gradient projection scheme with a special choice of step is used, this gives a converging sequence in the control space. The numerical solution of one variational problem of the mentioned type related to a one-dimensional heat conduction equation with boundary conditions of the second kind is presented. An inequality-type constraint is imposed on the control function entering the right-hand side of the ordinary differential equation. The numerical results obtained on the basis of the compiled computer program are presented in the form of tables and figures.
The described numerical method gives a sufficiently accurate solution in a short time and does not show a tendency to «dispersion». With an increase in the number of iterations, the value of the functional monotonically tends to zero
Thermal effect of a fire on a steel beam with corrugated wall with fireproof mineral-wool cladding
Authors: Nekora Valeriia , Sidnei Stanislav , Shnal Taras , Nekora Olga , Lavrinenko Ludmila , Pozdieiev Serhii
Published: November 2021

This paper reports a study into the possibility of applying a simplified approach, recommended by standards for conventional steel beams, to determine the heating temperature under the conditions of a fire in relation to steel I-beams with a corrugated wall. The research is predetermined by the limitation of methods that make it possible to determine the heating temperature of this type of beam in a fire using engineering methods with a small amount of calculations.
Technical data on steel beams with cladding have been considered for calculation, the features of heat impact of fire on them have been analyzed, a calculation procedure has been devised, the estimation schemes have been built, and the calculations have been performed. Data on the temperature distribution in the cross-sections of beams with and without cladding were obtained by using a simplified method recommended by standards and the refined method based on a finite-element method.
Mathematical models have been constructed for calculations that describe the effect of a standard temperature regime of fire on the distribution of temperature in each minute in the cross-sections of steel beams with and without cladding. The models have been described on the basis of the differential equation of thermal conductivity, boundary conditions of the third kind, which take into consideration convective and radiant heat transfer.
It was established that the mineral wool cladding of the beam with a corrugated wall is a reliable fire protection agent. The heating temperature of the beam does not reach a critical value of 500 °C in 60 minutes, which provides the class of this beam with the most stringent requirements for its fire resistance in accordance with the classification in line with the acting norms in Ukraine.
The simplified method, recommended by the current standards of the European Union and Ukraine, could be effectively used to analyze the fire resistance of these beams and is the basis of the procedure for the estimated assessment of the fire resistance of these structures
Devising a self-adjusting zero-order Brown’s model for predicting irreversible processes and phenomena
Authors: Pospelov Boris , Andronov Vladimir , Rybka Evgenіy , Krainiukov Olekcii , Maksymenko Nadiya , Biryukov Igor , Zhuravskij Maxim , Bezuhla Yuliia , Morozov Ihor , Yevtushenko Ihor
Published: November 2021

A self-adjusting zero-order Brown’s model has been devised. This model makes it possible to predict with high accuracy not only fires in the premises but also irreversible processes and phenomena of a random and chaotic nature under actual conditions. The essence of the self-adjusting model is that, based on Kalman’s approach, it is proposed to set the smoothing parameter for each time moment. Such a parameter is determined depending on the resulting current forecast error, taking into consideration the real and unknown dynamics of the studied series and noise. That does not require the selection of the smoothing parameter characteristic of known models. In addition, the proposed Brown’s model, unlike the known modifications, does not require setting a dynamics model of the level of the examined time series. The self-adjusting model provides negligible errors and efficiency of the forecast. The operability of the devised model was checked using an example of the experimental time series for the current measure of the recurrence of the increments of the state of the air medium in the laboratory chamber during alcohol combustion. As quantitative indicators of the quality of the forecast error, the current values for the square and absolute values were considered. It has been established that the current square of the forecast error is more than six orders of magnitude smaller compared to the case of a fixed smoothing parameter from a beyond-the-limit set. However, the current square of the forecast error for abrupt changes in the dynamics of the series level is half that of the fixed parameter of the beyond-the-limit set. It is noted that the results confirm the feasibility of the proposed self-adjusting Brown’s model
Optimization of the stages of a ship's cargo plan development for shippining of general cargoes
Authors: Loshkarov Oleksandr , Kornelyuk Olga
Published: November 2021

One of the main tasks in stability calculations is to provide the ship with the necessary (optimal) trim whose final value is influenced by the arrangement of cargo on the ship. Today, however, there are rules and requirements but there is no unified approach to developing a cargo plan for a vessel that simultaneously transports various types of general cargo.
In order to improve the efficiency of the above calculations, a procedure has been proposed to optimize developing a cargo plan for a vessel carrying heterogeneous general cargoes at the same time, the main idea of which is to distribute consignments on the ship in two stages, taking into consideration the compensating trimming moment. The scheme to develop a cargo plan has been improved by introducing the developed procedure. The results of verification confirmed its effectiveness in practice.
Possible deviations of the values for the trim required (optimal) for the voyage from the actual one calculated after the allocation of stocks and consignments of goods have been investigated using an example of the series of developed cargo plans. It should be noted that the value for the trim, required (optimal) and actual, for each individual cargo plan does not differ by more than 8 %.
The results reported in this paper give grounds to assert the expediency of their application when developing cargo plans for tramp shipping vessels. The introduction of the procedure could make it possible to effectively load a vessel with the full utilization of both its carrying capacity and cargo capacity. The use of the proposed scheme for developing a cargo plan to transport heterogeneous cargoes would reduce the total time for calculating the stability and strength of the vessel in general
A comparison of convolutional neural networks for Kazakh sign language recognition
Authors: Kenshimov Chingiz , Mukhanov Samat , Merembayev Timur , Yedilkhan Didar
Published: November 2021

For people with disabilities, sign language is the most important means of communication. Therefore, more and more authors of various papers and scientists around the world are proposing solutions to use intelligent hand gesture recognition systems. Such a system is aimed not only for those who wish to understand a sign language, but also speak using gesture recognition software. In this paper, a new benchmark dataset for Kazakh fingerspelling, able to train deep neural networks, is introduced. The dataset contains more than 10122 gesture samples for 42 alphabets. The alphabet has its own peculiarities as some characters are shown in motion, which may influence sign recognition.
Research and analysis of convolutional neural networks, comparison, testing, results and analysis of LeNet, AlexNet, ResNet and EffectiveNet – EfficientNetB7 methods are described in the paper. EffectiveNet architecture is state-of-the-art (SOTA) and is supposed to be a new one compared to other architectures under consideration. On this dataset, we showed that the LeNet and EffectiveNet networks outperform other competing algorithms. Moreover, EffectiveNet can achieve state-of-the-art performance on nother hand gesture datasets.
The architecture and operation principle of these algorithms reflect the effectiveness of their application in sign language recognition. The evaluation of the CNN model score is conducted by using the accuracy and penalty matrix. During training epochs, LeNet and EffectiveNet showed better results: accuracy and loss function had similar and close trends. The results of EffectiveNet were explained by the tools of the SHapley Additive exPlanations (SHAP) framework. SHAP explored the model to detect complex relationships between features in the images. Focusing on the SHAP tool may help to further improve the accuracy of the model
Analysis of the effect of ultrasonic vibration on nanofluid as coolant in engine radiator
Authors: Sudarmadji Sudarmadji , Santoso Santoso , Susilo Sugeng Hadi
Published: November 2021

The paper discusses the combined methods of increasing heat transfer, effects of adding nanofluids and ultrasonic vibration in the radiator using radiator coolant (RC) as a base fluid. The aim of the study is to determine the effect of nanoparticles in fluids (nanofluid) and ultrasonic vibration on the overall heat transfer coefficient in the radiator. Aluminum oxide nanoparticles of 20–50 nm in size produced by Zhejiang Ultrafine powder & Chemical Co, Ltd China were used, and the volume concentration of the nanoparticles varied from 0.25 %, 0.30 % and 0.35 %. By adjusting the fluid flow temperature of the radiator from 60 °C to 80 °C, the fluid flow rate varies from 7 to 11 lpm. The results showed that the addition of nanoparticles and ultrasonic vibration to the radiator coolant increases the overall heat transfer coefficient by 62.7 % at a flow rate of 10 liter per minute and temperature of 80 °C for 0.30 % particles volume concentration compared to pure RC without vibration. The effect of ultrasonic vibration on pure radiator coolant without vibration increases the overall heat transfer coefficient by 9.8 % from 385.3 W/m2·°C to 423.3 W/m2·°C at a flow rate of 9 liter per minute at a temperature of 70 °C. The presence of particles in the cooling fluid improves the overall heat transfer coefficient due to the effect of ultrasonic vibrations, nanofluids with a volume concentration of 0.25 % and 0.30 % increased about 10.1 % and 15.7 %, respectively, compared to no vibration. While, the effect of nanoparticles on pure radiator coolant at 70 °C enhanced the overall heat transfer coefficient by about 39.6 % at a particle volume concentration of 0.35 % compared to RC, which is 390.4 W/m2·°C to 545.1 W/m2·°C at 70 °C at a flow rate of 10 liter per minute
Experimental dependences of measurement data on the volume of inhaled air in multi-frequency electrical impedance tomography
Authors: Aleksanyan Grayr
Published: November 2021

This paper proposes an approach to modeling the process of artificial ventilation of human lungs by their controlled filling with a fixed volume of air, using an incentive spirometer Coach 2. This makes it possible to simulate the ventilation process for a healthy person and to link the assigned respiratory volume to measurement data. The results of experimental studies of the developed system of multifrequency electric impedance tomography are presented. The tests were performed for the frequency range from 50 kHz to 400 kHz (with a pitch of 50 kHz) at assigned respiratory volumes from 500 ml to 4,000 ml (with a pitch of 500 ml) for five inhalation/exhalation cycles. The scheme of research: active inhalation ‒ passive exhalation, the number of tested volunteers ‒ 3 people from the developers of the system. As a result, the dependences of the measured values of changes in potentials on the frequency of injected current for different respiratory volumes in three test participants without pathologies of the respiratory function and the external respiration function were obtained. The obtained results of the experimental studies show that there is a dependence of the value of the measurement data both on the volume of inhaled air and on the frequency of the injected current. This feature can be used to develop a number of medical devices for personalized monitoring of human lung function. It was also revealed that there are frequencies at which the maximum spread of measurement data according to the results of a series of repeated experiments is observed. At the same time, the nature of the change in the measurement data of the EIT at an increase in the volume of inhaled air is the same for all test participants. It is assumed that this feature can also be used to increase the EIT personalization degree
Implementation of the solution to the oil displacement problem using machine learning classifiers and neural networks
Authors: Daribayev Beimbet , Mukhanbet Aksultan , Nurakhov Yedil , Imankulov Timur
Published: November 2021

The problem of oil displacement was solved using neural networks and machine learning classifiers. The Buckley-Leverett model is selected, which describes the process of oil displacement by water. It consists of the equation of continuity of oil, water phases and Darcy’s law. The challenge is to optimize the oil displacement problem. Optimization will be performed at three levels: vectorization of calculations; implementation of classical algorithms; implementation of the algorithm using neural networks. A feature of the method proposed in the work is the identification of the method with high accuracy and the smallest errors, comparing the results of machine learning classifiers and types of neural networks. The research paper is also one of the first papers in which a comparison was made with machine learning classifiers and neural and recurrent neural networks. The classification was carried out according to three classification algorithms, such as decision tree, support vector machine (SVM) and gradient boosting. As a result of the study, the Gradient Boosting classifier and the neural network showed high accuracy, respectively 99.99 % and 97.4 %. The recurrent neural network trained faster than the others. The SVM classifier has the lowest accuracy score. To achieve this goal, a dataset was created containing over 67,000 data for class 10. These data are important for the problems of oil displacement in porous media. The proposed methodology provides a simple and elegant way to instill oil knowledge into machine learning algorithms. This removes two of the most significant drawbacks of machine learning algorithms: the need for large datasets and the robustness of extrapolation. The presented principles can be generalized in countless ways in the future and should lead to a new class of algorithms for solving both forward and inverse oil problems
Determining the optimal parameters of ultra-high-frequency treatment of chickpeas for the production of gluten-free flour
Authors: Omaraliyeva Aigul , Botbayeva Zhanar , Agedilova Mereke , Abilova Meruyert , Zhanaidarova Aidana
Published: November 2021

This paper describes the materials and results of studying the properties of such a leguminous crop as the chickpea variety Miras 07 of Kazakhstan selection in order to obtain gluten-free flour and further process it to produce confectionery products.
The research involved the ultra-high-frequency (UHF) treatment of chickpea grain to improve quality indicators and reduce anti-alimentary factors.
A change in the protein fraction of chickpeas was determined under exposure to ultra-high-frequency processing. The study has proven the effectiveness of ultra-high-frequency treatment of chickpea for 180 seconds.
Based on chemical analysis, it was found that the exposure to ultra-high-frequency treatment fully preserved the vitamin and mineral complex, compared with untreated chickpeas. When chickpea grain is heated for 180 seconds, up to 20 % of the starch contained in the grain passes into dextrin, which is easily absorbed by humans while the toxic substances are destroyed.
The change in the protein fraction of chickpeas during ultra-high-frequency processing was determined. With ultra-high-frequency treatment of chickpea flour at 180 seconds of exposure, the protein fraction content remains unchanged at 79.8 %. The result based on the IR spectrum data indicates that ultra-high-frequency processing did not affect the protein-amino acid composition of the examined Miras 07 chickpea variety.
The current study has confirmed the effectiveness of ultra-high-frequency chickpea treatment, which leads to the intensification of biochemical processes in the processed product due to the resonant absorption of energy by protein molecules and polysaccharides.
Under the influence of ultra-high-frequency treatment, there is a decrease in the microbiological contamination of raw materials while the organoleptic indicators improve. According to the microbiological indicators of chickpea flour, the content of microorganisms was 1×103 CFU/g, which meets the requirements for sanitary and hygienic safety
Technology development of fatty acids obtaining from soapstok using saponification
Authors: Sytnik Natalia , Kunitsia Ekaterina , Kalyna Viktoriia , Petukhova Olena , Ostapov Kostiantyn , Ishchuk Volodymyr , Saveliev Dmytro , Kovalova Tetiana , Kostyrkin Oleg , Petrova Olena
Published: November 2021

The processing of oil refining waste is essential from economic and environmental points of view. An important issue is the processing of soapstock to extract fatty acids, which are raw materials for various industries.
The two-stage method of fatty acids obtaining from soapstock using saponification with sodium hydroxide solution and decomposition with sulfuric acid is investigated.
The peculiarity of the work is the study of the influence of soapstock saponification conditions on the key efficiency indicators of fatty acid extraction: yield and neutralization number.
A sample of soapstock was obtained as a result of alkaline neutralization of sunflower oil. Soapstock quality corresponds to DSTU 5033 (CAS 68952-95-4): mass fraction of total fat – 68.5 %, fatty acids – 62.6 %, neutral fat – 5.9 %.
Rational saponification conditions were determined: duration (85 min.) and concentration of sodium hydroxide solution (45 %). After saponification, the soapstock was subjected to decomposition with sulfuric acid under the following conditions: temperature 90 °C, duration 40 min. Under the rational saponification conditions, the yield of fatty acids (91.8 %) and the neutralization number (187.1 mg KOH/g) were determined. The obtained fatty acids correspond to the first-grade fatty acids according to DSTU 4860 (CAS 61788-66-7). Acid indicators: mass fraction of moisture and volatile substances – 1.5 %, mass fraction of total fat – 98.0 %, cleavage depth – 69.2 % oleic acid.
The use of the soapstock saponification stage before decomposition leads to an improvement in the quality indicators and an increase in the neutralization number of fatty acids by 4 %, yield – by 16.2 %.
The results of the study make it possible to produce fatty acids from soapstock by two-stage technology with high yield and neutralization number