bluuebunny/crossref_metadata_2025_split huggingface dataset:
On a nonlinear parabolic problem with a boundary control and on its applications
Authors: Гольдман Н.Л. 
Published: August 2021

Рассматривается проблема оптимального управления системой, состоящей из краевой задачи первого рода для квазилинейного параболического уравнения с неизвестным коэффициентом, а также из уравнения изменения по времени этого коэффициента. Обоснованы две постановки вариационных задач с финальным наблюдением, в которых управлением является граничный режим на одной из границ области. Доказаны свойства непрерывности и дифференцируемости соответствующих минимизируемых функционалов. Дано явное представление для дифференциалов через решение сопряженных задач. Установлен вид этих сопряженных задач, доказана их однозначная разрешимость в классе гладких функций. Проведенное исследование связано с моделированием и управлением физико-химическими процессами с изменяющимися внутренними свойствами материалов.
We consider the optimal control in a system consisting of the boundary value problem of the first kind for a quasilinear parabolic equation with an unknown coefficient and an additional equation describing a time dependence of this coefficient. Two variational problems with a boundary control regime are substantiated for the given final observations. Some conditions of continuity and differentiability of the corresponding minimization functionals are formulated and proved. An exact representation for the differentials in terms of the solutions of the conjugate problems is obtained. The form of these conjugate problems and their unique solvability in a class of smooth functions are shown. This study is connected with modeling and control of physical-chemical processes in which the inner properties of materials are subjected to changes.
On Koenig's theorem for integer functions of finite order
Authors: Громов А.Н. 
Published: August 2021

Показано, что теорема Кенига о нулях аналитической функции, примененная к логарифмической производной целой функции конечного порядка, приводит к алгоритму отыскания нулей, для которого областями сходимости являются многоугольники Вороного искомых нулей. Так как диаграмма Вороного последовательности нулей составляет множество меры нуль, то алгоритм имеет глобальную сходимость. Дана оценка скорости сходимости. Для итераций высших порядков, которые строятся с помощью теоремы Кенига, рассмотрено влияние кратности корня на область сходимости и приводится оценка скорости сходимости.
It is shown that Koenig's theorem on zeros of analytic functions applied to the logarithmic derivative of an integer function of finite order leads to an algorithm of finding zeros whose convergence domains are the Voronoi polygons of the zeros to be found. Since the Voronoi diagram of a sequence of zeros is a set of measure zero, this algorithm is globally convergent. The rate of convergence is estimated. For higher-order iterations that are constructed using Koenig's theorem, the effect of root multiplicity on the convergence domain is considered and the convergence rate is estimated for this case.
Digital image reduction for analysis of topological changes in the pore space of the rock matrix during chemical dissolution
Authors: Прохоров Д.И. , Базайкин Я.В. , Лисица В.В. 
Published: August 2021

В работе предложен алгоритм редукции трехмерных цифровых изображений для ускорения вычисления персистентных диаграмм, характеризующих изменения в топологии порового пространства образцов горной породы. Воксели для удаления выбираются исходя из структуры своей окрестности, что позволяет редуцировать изображение за линейное время. Показано, что эффективность алгоритма существенно зависит от сложности устройства порового пространства и размеров шагов фильтрации.
A new algorithm for the reduction of three-dimensional digital images is proposed to improve the performance of persistence diagrams computing. These diagrams represent changes in topology of the pore space in the rock matrix. The algorithm has a linear complexity, since the removal of the voxel is based on the structure of its neighborhood. It is shown that the efficiency of the algorithm depends heavily on the complexity of the pore space and the size of filtering steps.
An experience of applying the parallelization regions for the step-by-step parallelization of software packages using the SAPFOR system
Authors: Колганов А.С. 
Published: August 2021

Одна из основных сложностей разработки параллельной программы для кластера — необходимость принятия глобальных решений по распределению данных и вычислений с учетом свойств всей программы, а затем выполнения кропотливой работы по модификации программы и ее отладки. Большой объем программного кода, а также многомодульность, многовариантность и многоязыковость, затрудняют принятие решений по согласованному распределению данных и вычислений. Опыт использования предыдущей системы САПФОР показал, что при распараллеливании на кластер больших программ и программных комплексов необходимо уметь распараллеливать их постепенно, начиная с наиболее времяемких фрагментов и постепенно добавляя новые фрагменты, пока не достигнем желаемого уровня эффективности параллельной программы. С этой целью предыдущая система была полностью переработана, и на ее основе была создана новая система SAPFOR (System FOR Automated Parallelization). В данной статье будет рассмотрен опыт применения метода частичного распараллеливания, идея которого заключается в том, что распараллеливанию подвергается не вся программа целиком, а ее части (области распараллеливания) — в них заводятся дополнительные экземпляры требуемых данных, производится распределение этих данных и соответствующих им вычислений.
The main difficulty in developing a parallel program for a cluster is the need to make global decisions on the distribution of data and computations, taking into account the properties of the entire program, and then doing the hard work of modifying the program and debugging it. A large amount of code as well as multimoduling, multivariant and multilanguage, make it difficult to make decisions on a consistent distribution of data and computations. The experience of using the previous SAPFOR system showed that, when parallelizing large programs and software packages for a cluster, one should be able to parallelize them gradually, starting with the most time-intensive fragments and gradually adding new fragments until we reach the desired level of parallel program efficiency. For this purpose, the previous system was completely redesigned and a new system SAPFOR (System FOR Automated Parallelization) was created. To solve this problem, the method of incremental or partial arallelization will be considered in this paper. The idea of this method is that not the entire program is subjected to parallelization, but only its parts (parallelization regions) where additional versions of the required data are created and distributed and the corresponding computations are performed. This paper also discusses the application of automated mapping of programs to a cluster using the proposed incremental parallelization method and using the example of a NPB (NAS Parallel Benchmarks) software package.
Computational aspects of mathematical modeling of the shallow water hydrobiological processes
Authors: Сухинов А.И. , Чистяков А.Е. , Литвинов В.Н. , Никитина А.В. , Белова Ю.В. , Филина А.А. 
Published: August 2021

Статья посвящена изучению нелинейных эффектов в динамике популяции промысловой рыбы пиленгас Азовского моря при низкой и высокой ее численности с учетом эффекта Олли, конкуренции за ресурсы, таксиса, вылова, пространственного распределения биогенных веществ и детрита на основе многовидовой модели взаимодействия планктона и рыб. Дискретный аналог разработанной модельной задачи водной экологии, входящей в состав программного комплекса, получен на основе схем второго порядка точности с учетом частичной заполненности расчетных ячеек. Возникающая в процессе дискретизации система сеточных уравнений большой размерности была решена на основе модифицированного попеременно-треугольного метода, имеющего наибольшую скорость сходимости при условии асимптотической устойчивости разностных схем для параболических уравнений, эффективность которого была улучшена на основе уточненных спектральных оценок. Разработка эффективных параллельных алгоритмов численной реализации поставленной задачи биологической кинетики, ориентированных на многопроцессорную вычислительную систему (МВС) и графический ускоритель NVIDIA Tesla K80 с модификацией формата хранения данных, позволила анализировать процессы воспроизводства популяций биогидроценоза в режиме реального и ускоренного времени.
Paper covers the research of nonlinear effects in population dynamics of the pelengas commercial fish of the Azov Sea taking into account the Allee effect, competition for resources, taxis, catching, spatial distribution of biogenic matter and detritus based on a multi-species model of plankton and fish interaction. Discrete analogue of developed model problem of water ecology, included in a software complex, were calculated using schemes of second order of accuracy taking into account the partial filling of computational cells. The system of grid equations of large dimension, arising at discretization, has been solved on the basis of adaptive modified alternately triangual variational method. Effective parallel algorithms were developed for numerical implementation of biological kinetics problem and oriented on multiprocessor computer system and NVIDIA Tesla K80 graphics accelerator with the data storage format modification. Due to it, the reproduction processes of biogeocenose populations have been analyzed in real and accelerated time.
One-dimensional finite difference schemes for splitting method realization in axisymmetric equations of the dynamics of elastic medium
Authors: Садовский В.М. , Садовская О.В. , Ефимов Е.А. 
Published: August 2021

Строятся экономичные разностные схемы сквозного счета для решения прямых задач сейсмики в осесимметричной постановке. При распараллеливании алгоритмов, реализующих схемы на многопроцессорных вычислительных системах, применяется метод двуциклического расщепления по пространственным переменным. Одномерные системы уравнений на этапах расщепления решаются на основе явных сеточно-характеристических схем и неявной разностной схемы типа "предиктор-корректор" с контролируемой искусственной диссипацией энергии. Верификация алгоритмов и программ выполнена на точных решениях одномерных задач типа бегущих монохроматических волн. Сравнение результатов показало неоспоримые преимущества схемы с контролируемой диссипацией энергии по точности расчета гладких решений и целесообразность применения явных монотонных схем при расчете разрывов.
We construct efficient finite difference shock-capturing schemes for the solution of direct seismic problems in axisymmetric formulation. When parallelizing the algorithms implementing the schemes on multiprocessor computing systems, the two-cyclic splitting method with respect to the spatial variables is used. One-dimensional systems of equations are solved at the stages of splitting on the basis of explicit gridcharacteristic schemes and an implicit finite difference scheme of the “predictor–corrector” type with controllable artificial energy dissipation. The verification of algorithms and programs is fulfilled on the exact solutions of one-dimensional problems describing traveling monochromatic waves. The comparison of the results showed the advantages of the scheme with controllable energy dissipation in terms of the accuracy of computing smooth solutions and the advisability of application of explicit monotone schemes when calculating discontinuities.
Economical efficiency of disinfestation of soil in trichocephalosis of sheep
Authors: Mamedova Matanat Magerram kyzy 
Published: August 2021

For the first time in the soil-climatic condition of the west region of Azerbaijan economical efficiency disinfestation of soil in trichocephalosis of sheep is found out. The use of solution sodium hypochlorite as disinfestational preparation in condition of bad trichocephalosis of sheep farm let it get more effective results using the least expenditure force and means. The efficiency of disinfestation is explained by high bioavailability of the preparation and optimal concentration of acting substance. It was identified that economical disinfestation of soil with the use of sodium hypochlorite is 22,30 azn (1 azn= 0, 022 ruble).
Differentiation of yield and grain quality of winter wheat varieties depending on agrotechnological techniques in the conditions of the Smolensk region
Authors: Romanova Iraida Nikolaevna , Nikitin Alexander Nikolaevich , Ptitsyna Natalia Vasilevna , Puzik Alexander Alexandrovich , Perepichai Marina Igorevna , Lyakina Olga Aleksandrovna 
Published: August 2021

The research was aimed at studying the formation of the yield level, as well as the quality indicators of winter wheat grain, depending on the studied agricultural practices (the seeding rate, the dose of mineral fertilizers), as well as the suitability of grain for its further processing. The objects of research in the experiment were new varieties of winter wheat of domestic selection: Solnechnaya and Danaya. The highest yield was in the winter wheat varieties Danaya (5 million pieces/ha) and Solnechnaya (5.5 million pieces/ha) with fractional application of nitrogen fertilizers according to the scheme N30+60+30P90K90 kg/ha a.i. It was 6.17 and 5.68 t/ha, respectively. In terms of yield, the Danaya variety is higher than the Solnechnaya variety by 0.49 t / ha. Physico-chemical and technological indicators were the highest with fractional application of nitrogen fertilizers (N30+60+20+10P90K90). Thus, in the winter wheat variety, the solar mass of 1000 grains increased by 4.60 g; nature-by 42 g/l; protein content-by 1.10%; vitreous-by 10%; gluten content - by 8.6%. The grain of the Danaya winter wheat variety was distinguished by physical and chemical parameters. The difference between the varieties was: 5.57 g; 71 g / l; 14%; 1.6%; 8.5%, respectively. Nitrogen fertilizers with their fractional application at a dose of 120 kg / ha d. v. for both varieties increases not only the yield, but also the quality of grain suitable for food, baking and technological purposes.
Using multivariate statistical methods to estimate the model maize population
Authors: Gudova Lyudmila Aleksandrovna , Zaytsev Sergey  Aleksandrovich , Zhuzhukin Valeriy  Ivanovich , Kurasova Lyudmila Gennadievna , Lekarev Andrey Vladimirovich 
Published: August 2021

In order to objectively assess the degree of similarity of varieties and hybrids by a set of indicators and to interpret a large amount of data in breeding practice, methods of multidimensional statistics are used, including factor and cluster analyzes. The study included 42 maize hybrids (FAO 100-499) of the selection of various scientific institutions of Russia, which were assessed according to the following characteristics: the length of the interphase stage of seedlings - flowering of panicles and ears, plant height, ear attachment height, grain yield, number of grains per ear, crude protein and crude fat content. Factor analysis made it possible to calculate the correlation coefficients between the variables under consideration and to reveal high positive correlations between the interfacial stages of a panicle seedlings–flowering and seedlings–-flowering of ears (r = 0.99), plant height and ear attachment height (r = 0, 81), the length of the interphase periods and the ear height (r = 0.77). A significant correlation coefficient was determined between the traits, the length of the interphase periods, seedlings – flowering of panicles and ears with grain yield (r = 0.34 and 0.36, respectively), grain yield and number of grains per ear (r = 0.37). When calculating the weights of the variables for the components, it was found out that the largest contribution (variance 54.814%) to the first hypothetical factor was made by the following signs: interphase periods of panicle seedlings–flowering and of ear seedlings–flowering, plant height, ear attachment height, grain yield, 1000 grain weight. The use of cluster analysis made it possible to group the studied hybrids at 32 iteration steps (Euclidean distance - 7.340) into 10 clusters with different breeding values. The hybrids that make up the clusters are characterized by a similar set of features within the clusters and significant differences between the clusters, confirmed by the method of unorganized repetitions of one-way ANOVA.
Peculiarities of genital tract microbiocenosis and immunological homeostasis in reproductive-age women with uterine leiomyoma
Authors: Kornatska A.H. , Trokhymovych O.V. , Chubei G.V. , Flaksemberh M.A. , Stamboli L.V. 
Published: August 2021

The objective: To determine the features of the microbiocenosis of the genital tract and immunological homeostasis and in women of reproductive age with uterine leiomyoma.Materials and methods. The microbiocenosis of the genital tract and immunological homeostasis of 308 women with uterine leiomyoma aged 23–49 years were studied. The control group included 30 healthy women aged 24–37 years. Results. In women of reproductive age, the development of uterine leiomyoma is associated with a significant violation of the microecology of the genitals, the presence of nonspecific vaginitis and bacterial vaginosis, increased frequency and concentration of pathogenic flora (staphylococci and streptococci with hemolytic properties, enterobacteria), STIs or reducing the concentration of protective microflora.The study of the peculiarities of the functioning of the immune system at the local level in the presence of uterine leiomyoma indicates unidirectional disorders in the state of local immunity and changes in the protective function of cervical mucus in the examined women. Thus, under conditions of uterine leiomyoma, there is a significant activation of local immunological factors, as evidenced by a significant increase in the concentration of IgG, IgA and the appearance of IgM in cervical mucus in 27,5–32,5 % of women with uterine leiomyoma. In addition, there was suppression of phagocytic activity of neutrophils, which was manifested by a significant decrease in activity and intensity of phagocytosis, with a decrease in their functional reserve by NRT test, which creates conditions for intracellular persistence of infection, activation and persistence of inflammatory progression.Conclusions. The obtained data indicate a violation of the microecology of the genitals and the intensity of immunogenesis in women with uterine leiomyoma, which indicates that the inflammatory process of the genitals is one of the significant factors that lead to the emergence and progression of uterine leiomyoma.
Fixed time synchronization of a class of chaotic systems based via the saturation control
Authors: Fu Jiaojiao , Luo Runzi , Huang Meichun , Su Haipeng 
Published: August 2021

In this paper, we discuss the fixed time synchronization of a class of chaotic systems based on the backstepping control with disturbances. A new and important fixed time stability theorem is presented. The upper bound estimate formulas of the settling time are also given which are different from the existing results in the literature. Based on the new fixed time stability theorem, a novel saturation controller for the fixed time synchronization a class of chaotic systems is proposed via the backstepping method. Finally, the new chaotic system is taken as an example to illustrate the applicability of the obtained theory.
Syrinx shunts for syringomyelia: a systematic review and meta-analysis of syringosubarachnoid, syringoperitoneal, and syringopleural shunting
Authors: Rothrock Robert J. , Lu Victor M. , Levi Allan D. 
Published: August 2021

OBJECTIVE
Syringomyelia is a debilitating, progressive disease process that can lead to loss of neurological function in patients already experiencing significant compromise. Syringosubarachnoid, syringoperitoneal, and syringopleural shunts are accepted treatment options for patients with persistent syringomyelia, but direct comparisons have been lacking to date. The authors conducted a systematic review of the literature and meta-analysis to compare clinical outcomes between these three syrinx shunt modalities.

METHODS
Utilizing PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for systematic reviews, Ovid Embase, PubMed, Scopus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, American College of Physicians Journal Club, and Database of Abstracts of Review of Effectiveness were searched to identify all potentially relevant studies published from inception until July 2020. Data were extracted and analyzed using meta-analysis of proportions. The primary study outcome was the rate of reoperation based on the initial shunt modality. Secondary outcomes included clinical improvement, clinical deterioration, and complications following shunt placement.

RESULTS
A total of 22 articles describing 27 distinct treatment cohorts published between 1984 and 2019 satisfied the inclusion criteria. This captured 473 syrinx shunt procedures, 193 (41%) by syringosubarachnoid shunt, 153 (32%) by syringoperitoneal shunt, and 127 (27%) by syringopleural shunt, with an overall median clinical follow-up of 44 months. The pooled incidences of revision surgery were estimated as 13% for syringosubarachnoid, 28% for syringoperitoneal, and 10% for syringopleural shunts, respectively (p-interaction = 0.27). The rate of clinical improvement was estimated as 61% for syringosubarachnoid, 64% for syringoperitoneal, and 71% for syringopleural shunts. The rate of clinical deterioration following placement was estimated as 13% for syringosubarachnoid, 13% for syringoperitoneal, and 10% for syringopleural shunts.

CONCLUSIONS
The preferred modality of syrinx shunting remains a controversial topic for symptomatic syringomyelia. This study suggests that while all three modalities offer similar rates of clinical improvement and deterioration after placement, syringoperitoneal shunts have a greater rate of malfunction requiring surgical revision. These data also suggest that syringopleural shunts may offer the best rate of clinical improvement with the lowest rate of reoperation.