bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlocal dynamic temperature stress simulation
Authors: Kuvyrkin G N , Savelyeva I Yu , Kuvshinnikova D A
Published: May 2021

The development of technologies for obtaining consolidated structural materials has increased interest in modelling materials with a heterogeneous structure. For models of such materials, an important factor is the relationship between the characteristics of the micro-(nano- ) level and the laws of continuum mechanics at the macro level. The widespread use of modern structure-sensitive materials in extreme conditions is the reason for the urgency of the problem of developing methods of mathematical modelling that allow describing such materials. New nonlinear dynamic problems that arise in this case require a new approach to the study and prediction of the mechanical behavior of such materials under conditions of high-intensity external influences. The paper considers a nonlocal model of dynamic temperature stresses. The model is based on the methods of globalized continuum mechanics. The basic equations of the model are derived from conservation laws. The model of thermomechanical processes in a nonlocal medium includes integro-differential equations with various boundary conditions. Equations describe stress in structural members. Also, the paper proposes an algorithm based on the finite element method to solve the problem. The distributions of temperature stresses in the nonlocal layer of the material are obtained and the influence of the main parameters of nonlocality on the solution of the problem is analyzed.
Examples of controlling the technological stress state characteristics of layer-by-layer manufactured products in the framework of the accreted solid model
Authors: Parshin D A
Published: May 2021

A mathematical model of quasi-statics of accreted deformable solids is proposed for the mechanical analysis of technological processes of slow multilayer power winding of a thin sheet onto the outer side surface of a sufficiently rigid circular mould made in advance. By using the analytical dependences obtained in the framework of this model, two problems of different type on the technological control of the characteristics of the formed product stress state developing during the winding process are formulated and analytically solved. In these problems, setting appropriate programs for changing in course of this process the thickness of the wound sheet and the tension force applied to it is used as the controlling impact.
The method of boundary states with perturbations as applied to the analysis of geometrically non-linear elastostatic bodies
Authors: Penkov V B , Levina L V , Novikov E A , Nazarov S Yu
Published: May 2021

This study makes a case for the application of the numeric and analytic method of boundary states with perturbations (MBSP) to analytic problems focused on the stress-strain states (SSS) of geometrically non-linear isotropic elastic bodies. The defining relations are represented through a weakly non-linear operator equation that contains (on an additive basis) a non-linear operator decomposable into a linear combination of a sequence of linear operators. A solution is proposed for a simple case of a linearly heterogeneous uniaxial loading problem for a long half-pipe with butt ends subjected to loads. Even in this load scenario, geometrical non-linearity affects the way the body alters its shape and causes buckling. This study analyzes the SSS involved, draws conclusions, and addresses application prospects.
High accurate sine and cosine interpolation with repeated differentiation ability obtained by fast expansions technique
Authors: Chernyshov A D , Popov M I , Litvinov D A
Published: May 2021

Fast trigonometric interpolations on a finite interval with different basis functions and increased accuracy are provided. Sine interpolation exactly coincides with this function at the interpolation points, and derivatives of cosine interpolation of the second example exactly coincide with derivatives of the said function at the interpolation points. In all cases interpolations allow differentiation for a given number of times being equal to the order of a certain boundary function. The applied Fourier series converge quickly and hence they can be limited to a small number of terms, thus greatly saving computing time. These special features allow their use in solving complex applied multi-dimensional problems of integro-differential type. The compact formulas for trigonometric interpolations in an explicit form are given which facilitate their application. An error estimate is provided and, algorithms for applying the described interpolations are setup.
Possibilities for predicting the state of usability web resources
Authors: Astachova I F , Makoviy K A , Khitskova Yu V
Published: May 2021

The article discusses the possibilities of predicting the state of the web resources usability. The usability testing procedure is quite costly from both financial and time points of view. Therefore, a system that reduces these costs is useful for modern organizations. Different approaches of forecasting the number of visitors: ARIMA model and Neural Networks are considered. An important time series property for ARIMA model being applicable is the stationarity of the series. It is shown that this model is not suitable enough for the investigated time series, some types of neural networks are also not suitable for various reasons. As a result, NARX networks are selected, which are successfully used for time series forecasting, providing an opportunity to use an exogenous variable.
Spectral analysis of one class perturbed first order differential operators
Authors: Garkavenko G , Uskova N
Published: May 2021

We use the method of similar operators to study a mixed problem for a first order differential equation with a fractional integration operator. The differential operator defined by the equation is transformed into a similar operator that is an orthogonal direct sum of finite-rank operators. The estimates of eigenvalues, eigenvectors are obtained. The result is used to construct an operator group.
On one physical interpretation of generalized conditions Cauchy-Riemann
Authors: Gladyshev Yu A , Loshkareva E A
Published: May 2021

The message shows that in variables, the generalized Cauchy-Riemann conditions (CRC) coincide with the Maxwell system for the electromagnetic field, and the possible existence of magnetic charges and currents is assumed. This makes it possible to give a physical interpretation to all 8 components of the solution of generalized СRС. When the generalized СRС is taken as a basis, two scalar fields necessarily appear. They are interpreted as some fields of spatially distributed electric and magnetic charges and currents. The introduction of the attached generalized СRC allows us to give a method for determining the potentials of the electromagnetic field under the assumptions made and to determine the gauge transformations more General than the well-known ones. Of course, having made certain restrictions, all the results coincide with those accepted in classical electrodynamics. The author points out that he does not make any physical statements and all constructions are purely mathematical in nature.
Stability of differential-difference parabolic system with distributed parameters on the graph
Authors: Provotorov V V , Zhabko A P
Published: May 2021

The work presents the results of the analysis of the approximation of a differential system with distributed parameters on the network domain. This approximation consider in a space of summable functions with a compact bearer on network domain. The question is whether the differential system retains its main properties when its approximation – uniqueness weak solvability, continuity according to the input data, stability on Lyapunov and in what cases (under what conditions) it is possible to replace the analysis of the differential system by analysis of its differential-difference analogue. The study uses a simplified bearer of functions – graph, which is a private case of a network domain (the graph’s edges are parameterized by a one-dimensional spatial variable that changes on the graph). On the set of these functions study the differential-difference equation. This simplification only frees us from the unnecessary routine technical work, where the function bearer is an arbitrary the network domain of multi-dimensional Euclidean space, but as it does not affect on the transfer of ideas and results presented in the work to this multidimensional event. The transition from a differential system to a differential-difference analogue (differential-different system) is carried out using the method of finite difference on the time variable (Rote semi-digitization method). The conditions of weak uniquely solvability of differential-difference system and continuity of the input data are presented. guaranteeing the stability of a weak solution of differential-differential system. These conditions guarantee the stability of a weak solution of differential-difference system.
Experimental studies of the process of initiation and spread of the dangerous fire factors while burning of the tube stock in the tunnel
Authors: Aqeev P M , Sysoeva T P , Kukharev A A , Sobolev P M , Yakhontova O N
Published: May 2021

The present article is concerned with the analysis of the experimental results performed with full-size large-scale prototypes of tube stock in subways in case of the fire in the tunnel. The process of the fire spread in the passenger compartment and along the tube stock is investigated.
Distributed computing systems synchronization modeling for solving machine learning tasks
Authors: Azarnova T V , Polukhin P V
Published: May 2021

Distributed computing systems are an effective tool for solving complex problems related to processing large amounts of information and data, in particular, machine learning tasks. To improve the efficiency of these systems in solving complex tasks, special methods for synchronization processes modeling, evaluating and predicting processing delays and query execution, developed in the terms of this models. The approaches for the distributed computing systems organization based on the mathematical apparatus of queuing theory, considered in this paper, allow optimizing the requests processing mechanisms related to solving resource allocation problems, and increasing the consistency of computational processes related to machine learning problems.
Assessment of the quality of training of specialists in higher education institutions
Authors: Bezrydin S N , Lupanova A V , Kalach E V
Published: May 2021

The article presents the requirements and various ways to assess the quality of educational services and training of specialists in higher education institutions, and also offers a “comprehensive” indicator of the quality of management systems that takes into account the main results of educational activities of the University – the degree of development of educational programs by students and satisfaction of the main consumers of educational services.
Development of an information and analytical system for presenting data on the refractive properties of the environment
Authors: Bobrov V N , Dushkin A V , Sitnikov A I , Sushko E A
Published: May 2021

The article proposes a variant of constructing an information and analytical system that makes it possible to control the refractive properties of the environment (atmosphere) based on the actual values of its parameters, as well as to determine the numerical values of the refractive index of the atmosphere. Its operation is based on a method that makes it possible to detect errors during measurements by optical systems in a real atmosphere. The main feature of the method under consideration is the comparison of the refractive indices in a real and ideal atmosphere. The difference in the corresponding values of the refractive index of the atmosphere makes it possible to correct the results obtained during measurements by optical systems. This article describes the operation of the software algorithm, which allows not only measuring and evaluating based on information on hydrometeorological parameters and refractive properties of the surface layer of the atmosphere, but also visualizing the results of measurements carried out by optical systems. Experimental studies carried out confirm the high adequacy of the models underlying the described complex.
Construction of a dual attractor for linear randomized systems of iterated functions
Authors: Bukhovets A , Moskalev P , Biryuchinskaya T
Published: May 2021

The Legendre transform is applied to the attractors of linear randomized systems of iterated functions X
1 and X
2, construction using the ordered (F1) and disordered (F2) algorithms. The original attractors X
1 and X
2 have identical similarity dimension d

S
(X
1) = d

S
(X
2), but applying the Legendre transform to X
1 generates a set

X

1

*

with a linearly ordered structure and similarity dimension

1
<

d

S

(

X

1

∗

)

<

d

S

(

X

1

)

, and applying the Legendre transform to X
2 generates a set

X

2

*

with a disordered structure and similarity dimension

d

S

(

X

2

)

<

d

S

(

X

2

∗

)

<
2

.
Optimal deployment and principles of tracing for the distributing lines of pumping plants in the mountain terrain
Authors: Dmitriev E V , Kalach A V , Mokrozub V G , Cherepanov E A
Published: May 2021

In this paper, we propose new graphical algorithms for planning and optimal placement of pumps for outdoor fire extinguishing networks and propose mathematical optimization models for constructing various outdoor fire water supply networks for microdistricts located in mountainous areas (with significant elevation differences). The solution was carried out by constructing Fermat-Torricelli-Steiner points for the optimization problem of constructing a spatial dead-end network in three-dimensional space.
Integration of decoupling capacitors in the structure of controlled metamaterial
Authors: Ishchenko E A , Pasternak Yu G , Pendyurin V A , Fedorov S M
Published: May 2021

The article studies a metamaterial placed in the aperture of a rectangular waveguide with dimensions of 36x18.1 mm to change the phase of the transmitted wave depending on the switched pin diodes. Since pin diodes are switched by supplying a constant voltage to them in the metamaterial structure, capacitors with a capacitance of 35 nF were installed, which make it possible to achieve separation of the constant component of the switching voltage from the alternating one, and, accordingly, ensure switching only in the required nodes. The simulation results contain S-parameters of the system, which prove the possibility of using the proposed metamaterial as a waveguide phase shifter.
On some problems of modelling the non-stationary heat conductivity process in an axisymmetric multilayer medium
Authors: Kalmanovich V V , Kartanov A A , Stepovich M A
Published: May 2021

Some possibilities of solving the non-stationary heat equation in an axisymmetric multilayer medium are considered. The problem is solved by combining Fourier method and the matrix method. The solutions of the first and third boundary value problems are considered. Examples of calculations by the specified method for three-layer and five-layer axisymmetric systems are given.
On some concepts of nonlinear dynamics suitable for use in linguistics
Authors: Kretov A A , Polovinkina M V , Polovinkin I P , Lometc M V
Published: May 2021

In this paper, we describe hypothetical possibilities for applying nonlinear dynamics methods to linguistic research. We suggest to refer to a large text corpus (meta-book of the writer, national language, language of the branch of knowledge) as a fractal object and to measure its fractal dimension (by Hausdorff). We consider the question of practical calculation of fractal dimension, as well as the question of motivation for applying the fractal concept to the language. In addition, we propose to apply some methods of the qualitative theory of differential equations to modelling the growth of the natural language vocabulary.
Personalized medicine software solutions
Authors: Lavlinskaya O Yu , Kurchenkova T V
Published: May 2021

The article examines the example of the implementation of the telemedicine information system – “Medical information system of accompanying chronic diseases therapy”. Based on the current monitoring of blood pressure, heart rate, and antihypertensive therapy prescribed by the doctor. The concept of developing MIS meets the paradigm of modern medicine, supporting the concept of personification, prediction, prevention, patient involvement in the treatment process based on a positive approach to therapy for patients with hypertension. Formal approaches to automatic correction of therapy based on the method of tree solutions are considered.
Models and algorithms for optimizing security management of critical social infrastructure facilities
Authors: Rossikhina L V , Orlova D E
Published: May 2021

Algorithms for managing complex security of objects of critical application are proposed. they differ from their analogues in that classical optimization models are supplemented with coordination models that allow taking into account multi-criteria, hierarchy and interconnectedness of components of managed objects.
Adaptation of the finite element method for a mathematical model on a geometric graph
Authors: Shabrov Sergey , Litvinov Dmitrii
Published: May 2021

In the present paper finite element method is adapted to finding an approximate solution of a mathematical model describing small forced vibrations of a stretched grid of strings located along a geometric graph.
Research of the process of functioning of hierarchical multi-level complex organizational systems
Authors: Sumin V I , Smolentceva T E , Zybin D G , Ageev P M , Golovkin R B
Published: May 2021

In the work the process of increase of efficiency in the functioning of hierarchical multi-level complicated organizational systems (HMCOS) is considered and the elements of operation in the considered systems. To solve this problem the tension level of HMCOS operation is involved. Basing on the formulated principles some normative parameters of HMCOS are defined. Validation of the operation process for HMCOS is performed by the normative parameters in the certain moments of time. Considering all of the stages in HMCOS functioning it was made a conclusion that while choosing the normative parameters for the estimates of functioning of the organizational systems in order to get uniform distribution of tension between the staff it seems reasonable to use entropy model.
Application of the information systems in decision-making at the different levels of an enterprise management
Authors: Sumin V I , Zybin D G , Gantz I S , Golovkin R B , Berger E G
Published: May 2021

Specific features of the information support for the process of decision-making while the enterprise management are considered in the work as well as the architecture of the information systems of a certain kind has been developed. The use of the models during making the analysis in the systems of support for decision-making is developed just as the assessment of the capabilities for these systems are validated at the different levels of management. The goals of support at the high level are examined and the possibility of the use of cognitive images is described as the instrument for data visualization.
Implementation of finite element method for solid mechanics problems in Julia programming language
Authors: Antoshkin A D , Cherednichenko A V , Savelyeva I Yu
Published: May 2021

The paper proposes finite element method algorithm implemented in Julia programming language. The main features of Julia programming language are described. The results of Kirsch problem solution are presented. Comparing obtained results with appropriate calculations with open-source finite element software Code Aster are also presented.
Solving the diffusion-convection problem using MPI parallel computing technology
Authors: Atayan A M
Published: May 2021

The aim of the work is to build a software package for the distributed solution of the problem of matter transfer in a reservoir. A parallel implementation of the grid domain decomposition methods for computationally complex diffusion-convection problems, taking into account the architecture and parameters of a multiprocessor computing system located on the basis of the infrastructure facility of the University of Science and Technology «Sirius», is considered. An algorithm for parallel solution of the formulated hydrophysics problem using MPI technology has been developed. The analysis of the efficiency of the developed parallel algorithms is carried out and the study of the obtained solutions of computationally complex problems of aquatic ecology is carried out.
Necessary and sufficient conditions for the existence of a classical solution of the mixed problem for the wave equation on a graph
Authors: Burlutskaya M Sh
Published: May 2021

We study a mixed problem for the wave equation with integrable potential on the simplest geometric graph consisting of two ring edges that touch at a point. We use a new approach in the Fourier method to obtain necessary and sufficient conditions for the existence of a classical solution. We do not use refined asymptotic formulas for the eigenvalues and any information on the eigenfunctions. The solution is represented by a rapidly convergent series.
Interval estimation of conditional probabilities in Bayesian Belief Network
Authors: Gagarin Yu E , Nikitenko U V , Stepovich M A
Published: May 2021

An interval estimation of conditional probabilities in Bayesian belief network is considered, taking into account the uncertainty of the initial data. To account for errors in the values of functions and arguments, it is proposed to use confluent analysis methods. It is assumed that the conditional probability densities correspond to the normal distribution law. Formulas for interval estimation of conditional probability densities are given, taking into account the errors of their parameters. The results of mathematical modeling of obtaining point and interval estimates of conditional and a posteriori probabilities of the Bayesian belief network are shown.
Computer modeling of process in earth structures of dam type
Authors: Gaynazarov S M , Polatov A M , Ikramov A M , Pulatov S I
Published: May 2021

The article deals with computer modeling of processes in earth structures of dam type, taking into account the nonlinear properties of soil. Large vertical and planned displacements of soil in the body of the dam are formed due to changes in soil density or as a result of the development of plastic shear strains. The application of the von Mises-Botkin and Coulomb hypotheses to the development of plastic strain is investigated.
Mathematical modeling of elastic soil acid treatment
Authors: Galtsev O V
Published: May 2021

The study is devoted to an initial boundary value problem describing the process of cleaning the bottomhole zone of an oil well with acid solution. It is assumed that the soil frame is an elastic solid body and the pore space has double porosity. The physical process is described at the microscopic level by the Stokes equations for the liquid component, the diffusion-convection equation for the concentrations of acid and chemical reaction products, and the Lame equations for the solid frame. Due to soil dissolution, the pore space has an unknown (free) boundary. The lattice Boltzmann method (LBM), the immersed boundary method (IBM) and the finite element method (FEM) are used for computer simulation. Finally, discretization of equations and results of numerical solutions are presented.
Numerical investigation of compact grid-characteristic schemes for acoustic problems
Authors: Golubev V I , Shevchenko A V , Khokhlov N I , Nikitin I S
Published: May 2021

In this paper, an acoustic approximation is considered, which allows to describe the propagation of longitudinal waves in geological media. For the two-dimensional case, a compact numerical scheme is described that provides an increased approximation order on a two-point spatial stencil. To construct it, we used the method of splitting along coordinate axes and the differential continuation of the original system of equations. A number of numerical tests have been carried out, confirming the increased order of approximation.
Development of the mathematical model of the force actuator for deployment of large-sized space structures
Authors: Zimin V N , Krylov A V , Shakhverdov A O
Published: May 2021

A special class of large-sized space systems is formed by transformable structures that have different configurations in transport and operating states. Transformable large-sized space structures are delivered into orbits in a folded transport state and after that they are deployed into operating position. Now problems of the mathematical modeling of deployment dynamics of such systems attract a great interest of scientists. When the structure is transformed, impact dynamic loads arise in the system elements. To ensure a smooth «controlled» opening of the transformable structures and to exclude the dynamic impact loads in their constructed elements, it is proposed to use force actuators made of material with a shape memory effect. Now, to create mechanisms with elements made of the materials with the shape memory effect, the role of experimental methods is very important. Preliminary experimental studies of the force actuator made of such material as titanium nickelide were carried out. Deformation and force characteristics of the actuator obtained in these studies prove the possibility to use it for reliable deployment of the promising transformable space structures. Based on the fulfilled theoretical and experimental studies, the mathematical model describing the force actuator functionality is proposed.
Solution of the first basic physically nonlinear problem of elasticity theory for anisotropic bodies
Authors: Ivanychev D A , Novikov E A
Published: May 2021

The study looks upon the process of the physically non-linear deformation of transversely isotropic homogeneous continuous solid bodies made from composites where the reinforcing elements are far more rigid than the binder. The solution of the physically non-linear problems employs the simplified theory of plasticity as proposed by B.E. Pobedra. The study proposes an approach to the writing out of an explicit solution that builds on the small parameter method. Ilyushin plasticity functions (that fall within the generalized Hooke’s law) are assigned discrete small values, and the resulting equations are then decomposed into power series in small parameters. The values of such small parameters are the measures of the deflection of the non-linear vs. the linear medium. Such decomposition produces an analytical coordinate & small parameters function enabling an immediate solution of the non-linear problem using just one linear elasticity field, which, in turn, is also created exclusively in reliance on the method of boundary states. Below are the results of solutions of test problems featuring a transversely isotropic cylinder with homogeneous boundary conditions. High precision in this case is achieved as early on as the third iteration. In problems with non-trivial boundary conditions, maximal precision is achieved at the first iteration and heavily depends on small parameter values. Each of the problems presented provides a detailed convergence analysis and graphic illustrations of the results.
Calculation of the problem of thermoplasticity on the example of a stationary power plant flange using free software Code Aster
Authors: Maksimova E A , Cherednichenko A V , Savelyeva I Yu
Published: May 2021

The construction of a geometric model and finite element approximation of the flange of a stationary power plant is presented. Modelling and meshing were held using Salome-Meca modules. The paper provides a brief description of the key commands in AsterStudy module for modeling this problem. A numerical calculation of the heat-stress state of the flange of a stationary power plant was performed using free Code Aster software. Distributions of temperature for four periods, flange deformation, displacements, and also equivalent von Mises stresses are given as a results of the study.
Modified ant colony optimization algorithm for solving the vehicle routing problem with a given load capacity
Authors: Medvedev S N , Medvedeva O A
Published: May 2021

The article presents a mathematical model of the Vehicle routing problem with loading constraints in the form of a mathematical programming problem. A modification of the Ant colony optimization algorithm is presented to solve the problem. The main idea of the modification is to use the probabilistic rule of returning the agent (ant) to the depot before full unloading. The source of such behavior of the agent can be the concept of «fullness» of the ant. The computational experiment for comparing the classical and modified Ant colony optimization algorithms is presented. Testing was carried out according to two schemes: intensive testing and cross-testing. The conclusions about the efficiency of the proposed algorithm are presented.
An approach to design of large-sized deployable hoop space antenna reflector
Authors: Meshkovsky V Ye , Sdobnikov A N , Kisanov Yu A
Published: May 2021

Amongst the large-sized transformable space antennas, the most attention is currently paid to developing of antennas with hoop-shaped reflectors. The developers are faced with the necessity of looking for optimal design concepts. This paper shows the various concepts of building of the reflectors of the cable-rod scheme, containing a circular load-bearing framework (load-bearing rim) with a deployment drive set on it and the reflecting surface shape-generating structure, assembled into a single construction by the cable and rod elements. The difference between the proposed design concepts of the reflectors is the various structures of the controllable unfolding mechanisms. In the first alternative of the reflector structure, the unfolding process is supported by the cable, which restrains relative displacements of the tips of the initially compressed springs. The second alternative supposes the cable not to be the restraining element, but an active unit of the unfolding mechanism. This paper also describes various alternatives for connection between tension tie cables and the load-bearing rim. It is shown that the alternative of connection of the tension tie cables to the middles of the load-bearing rim edges allows to perform stress analysis of the structure elements and to obtain required characteristics of the spring drive. The numerical calculations for optimal angular position of the deployment drive pulleys holder relative to the sections of the load-bearing rim for the second alternative of the reflector design, which provides the most force effect on shape-generating structure of the reflector, when the knitted mesh fabric is being pulled, are under consideration in this article. The calculations are confirmed by experimental investigations.
Design features of an information-measuring and control system for landing a swarm of small unmanned aerial vehicles
Authors: Pasechnikov I I , Pasechnikov R I , Nazarov A S , Rodionov D V
Published: May 2021

The problem of a small unmanned aerial vehicles (SUAV) swarm landing on a robotic platform is solved. The necessity of creating a controlled waiting area for a SUAV in the landing system is shown using simulation. The principle of SUAV air traffic organisation in the space-time waiting zone and the issues of a safe landing are revealed. The structure of the information-measuring and control system of the SUAV landing with the space-time waiting area and the buffer landing zone is proposed. Its main features are given and the possibility for landing a SUAV swarm of various structure is shown.
River mouth areas hydrodynamics mathematical modeling
Authors: Sukhinov A I , Kuznetsova I Yu , Chistyakov A E , Litvinov V N
Published: May 2021

The article is devoted to the mathematical modeling results description of hydrodynamic processes in seas mouth areas. 3D hydrodynamics mathematical model description is given, which is used to calculate the 3D velocity vector fields of the aquatic environment movement in mouth areas. The approximation of the differential equations of the mathematical model is based on the balance method taking into account the fullness of the control areas. The use of this combination of methods made it possible to more accurately description the complex geometry of the coastline and seabed. Due to this, it was possible to reduce the calculation error at the boundaries of the computational domain and to increase the calculation accuracy. A software package for modeling hydrodynamic processes in mouth areas has been developed in C++. The description of the software package and the results of its operation are given.
Using of machine learning methods in cardiology
Authors: Firyulina M A , Kashirina I L
Published: May 2021

In the modern world, artificial intelligence and machine learning affect many areas of life. Medicine is no exception. It is one of the most important areas of application of intelligent technologies. This article describes the experience of building machine learning models in cardiology and discusses the features of their development, analyses various machine learning algorithms used in problems of cardiological practice, examines ways to improve their accuracy and efficiency.
Application of the Q-learning algorithm for the intellectual mode of the manipulator arm for moving to a present position
Authors: Yakovlev A Yu , Krasnaya A A , Medvedev S N
Published: May 2021

The article is devoted to the search for a certain kinematic scheme that determines the movement of the arm links of an industrial manipulator. A robotic complex with a single-circuit hydraulic system of arm element drives is considered. The problem of the automatic transition of the arm to a user-specified state has been solved, taking into account the restrictions on the simultaneous movement of the arm links and the minimum and maximum heights of the manipulator. To solve the problem, we used the machine learning method – Q-learning.
Radiopacity endowed magnetic nanocomposite with hyperthermia and in vitro mineralization potential: a combinatorial therapeutic system for osteosarcoma
Authors: Sneha K R , Sreeja S , Sailaja G S
Published: May 2021

The development of clinically advanced multifaceted therapeutic materials for osteosarcoma is at the forefront of cancer research. Accordingly, this work presents the design of a multifunctional magnetic nanocomposite composed of maghemite, strontium doped hydroxyapatite and silica nanoparticles prospectively holding indispensable therapeutic features such as magnetic hyperthermia, in vitro biomineralization, sustained drug release and intrinsic radiopacity for the treatment of osteosarcoma. The optimal composition has been identified by sequentially modulating the ratio of precursors of the magnetic nanocomposite synthesized by sol–gel technique. Structural and morphological characterization by x-ray diffraction, fourier transform infrared spectrum, Brunauer–Emmet–Teller and transmission electron microscopy analyses followed by VSM, hyperthermia and micro-CT analyses essentially assisted in the selective configuration of biofunctional properties. Results exemplify that MSHSr1 has a saturation magnetization of 47.4 emu g−1 and attained hyperthermia temperature (42 °C) at a very low exposure time of 4 min. MSHSr1 is further unique with respect to its exceptional x-ray attenuation ability (contrast enhancement 154.5% in digital radiography; CT number 3100 HU), early biomimetic mineralization (in vitro) evident by the formation of spheroidal apatite layer (Ca/P ratio 1.33) harvested from FESEM–EDX analysis and controlled release of Doxorubicin, the clinically used chemotherapeutic drug: 87.7% at 120 h in tumour analogous pH (6.5) when compared to physiological pH (71.3% at 7.4). MTT assay complemented with cytoskeleton (F-actin) staining of human osteosarcoma (HOS) cells affirm biocompatibility of MSHSr1. In vitro biomineralization authenticated by Alizarin red S and von Kossa staining has been further corroborated by semi-quantitative calcium estimation of HOS cells cultured with MSHSr1 for two weeks. The results therefore validate the multifunctionality of MSHSr1, and hence could be proposed as a combinatorial therapeutic nanocomposite for osteosarcoma treatment.
Independent oil palm smallholder management practices and yields: can RSPO certification make a difference?
Authors: De Vos Rosanne E , Suwarno Aritta , Slingerland Maja , Van Der Meer Peter J , Lucey Jennifer M
Published: May 2021

Smallholders are a substantial part of the oil palm sector and thus are key to achieving more sustainable production. However, so far their yields remain below potential. The Roundtable on Sustainable Oil Palm (RSPO) aims to include smallholders in sustainability certification to strengthen rural livelihoods and reduce negative environmental impacts. This study aims to determine if and how certified smallholders perform differently from their non-certified counterparts in terms of management practices and yields, and to what extent this is related to RSPO certification. Certified smallholders had significantly better management practices in terms of planting material (tenera) and fertiliser use (16.8 vs 4.8 bags ha−1 yr−1) and had significantly higher yields (22.5 vs 14.5 ton fresh fruit bunches ha−11 yr−11, corrected for palm age). Planting material and harvesting frequency significantly explained higher yields. These differences could not be attributed to certification per se but were probably due to pre-certification conditions, including strong group organisation. It remains a question as to how sustainability certification can be a driver of change by including smallholders who have relatively larger yield gaps, and who lag behind in eligibility criteria for certification.
Fractional Brownian motion in superharmonic potentials and non-Boltzmann stationary distributions
Authors: Guggenberger Tobias , Chechkin Aleksei , Metzler Ralf
Published: May 2021

We study the stochastic motion of particles driven by long-range correlated fractional Gaussian noise (FGN) in a superharmonic external potential of the form U(x) ∝ x
2n
(

n
∈
N

). When the noise is considered to be external, the resulting overdamped motion is described by the non-Markovian Langevin equation for fractional Brownian motion. For this case we show the existence of long time, stationary probability density functions (PDFs) the shape of which strongly deviates from the naively expected Boltzmann PDF in the confining potential U(x). We analyse in detail the temporal approach to stationarity as well as the shape of the non-Boltzmann stationary PDF. A typical characteristic is that subdiffusive, antipersistent (with negative autocorrelation) motion tends to effect an accumulation of probability close to the origin as compared to the corresponding Boltzmann distribution while the opposite trend occurs for superdiffusive (persistent) motion. For this latter case this leads to distinct bimodal shapes of the PDF. This property is compared to a similar phenomenon observed for Markovian Lévy flights in superharmonic potentials. We also demonstrate that the motion encoded in the fractional Langevin equation driven by FGN always relaxes to the Boltzmann distribution, as in this case the fluctuation-dissipation theorem is fulfilled.
Effect of cropping rotation patterns on rice productivity in irrigated rice fields
Authors: Suprihatin A , Purwanto B H , Hanudin E , Nurudin M
Published: May 2021

Crop rotation has an important role in increasing soil fertility (chemical, physical and biological), production, and sustainable land use. The aim of this study to determine the variables affecting rice productivity in irrigated rice fields in several crop rotation patterns. The fieldwork was taken place in irrigated rice fields, Imogiri District - Bantul, Yogyakarta, Indonesia. The experimental design used in this study was Oversite design, on four irrigated rice fields that applied four different crop rotation patterns: rice-rice-corn (RRM), rice-rice-soybean (RRS), rice-rice-rice ( CCR), and rice-rice-rice grown organically (COR). The rice variety Inpari 23 was grown during wet season (February - May 2018) while during dry season (June – September 2018), the rice variety Mentik Wangi was planted. The data were analyzed by ANOVA at 5% level, and continued with HSD level 5% using SAS 9.1.3. portable, while the correlation analysis used SPSS. The results showed that the highest production of MDG was obtained from CCR cropping pattern while the lowest production from RRM cropping pattern. The Inpari 23 grown in wet season produced higher MDG (6,092 kg ha−1 ) than Mentik Wangi which grown in dry season (5,110 kg ha−1 ). The production of MDG has a positive correlation with plant height, dry weight of grain and weight of 1.000 grains. Since the irrigated rice fields used in this study had a moderate level of fertility, the results showed that differences in crop rotation patterns and rice cultivation techniques in irrigated rice fields that have moderate soil fertility did not affect crop productivity. The productivity have more influenced by the choice of rice varieties planted in each planting period.
Effect of CaCl2 and Alginate-Essential Oil Edible Coating in Maintaining Quality and Antioxidant Content in Rose Apple cv. Dalhari
Authors: Anjani A M , Setiawan C K , Utama N A
Published: May 2021

Information on the treatment of edible coatings alginate and various concentrations of essential oils has not been known to antioxidant and anthocyanin changes in rose apple during storage.This study was aimed to determine the effect of CaCl2 and edible coating towards changes in antioxidants, anthocyanins, and chlorophyll during storage. It was also to determine the concentration of the best combination of immersion of CaCl2 and essential oils to the antioxidant, anthocyanin, and chlorophyll content found in rose apple var. Dalhari. The research was conducted by experimental CRD (Completely Randomized Design) factorial design. The first factor was the concentration of CaCl2 consist of two levels ie 0% and 2%. The second factor was the type and concentration of essential oil consist of 3 levels, namely 1% vanilla, 0.7% cinnamon and 0% essential oil. The results of the combination of CaCl2 and essential oils has no significant effect on antioxidant, anthocyanin, and chlorophyll content.
Response of Trichoderma sp and shallot varieties towards plant growth and disease incidence
Authors: Korlina E , Sulastrini I , Waluyo N
Published: May 2021

The main diseases that commonly attack shallots include purple blotch disease (Alternaria porri), anthracnose (Colletotrichum gloeosporioides), wilt (Fusarium oxysporum) and Stemphylium vesicarium. Purple blotch disease can cause yield losses of 3-57%. The research is aimed to measure the response of Trichoderma sp and other varieties to the growth and development of shallot disease. The study was conducted at IP2TP Margahayu Indonesian Vegetable Research Institute (IVEGRI), in August - November 2019. The research used a randomized block design (RBD) with 12 treatments and 3 replications. The treatments consisted of three varieties which are Batu Ijo, Sumenep, Trisula, Violeta 1, Maja Cipanas, and Ambasador in combination with Trichoderma and without Trichoderma. Results for the parameters of plant height and number of leaves showed that varieties that have been Trichoderma applied have reached higher height than those without Trichoderma. Ambasador showed the highest plant height (46.27 cm) and the highest number of leaves (44.16 cm). A The intensity of the purple blotch disease attacks A. porri (0.67-8,00%) and S. vesicarium (6.67-23.33%) on all varieties treated with Trichoderma lower than without Trichoderma s for the number of tillers, it is almost the same as an average of 6-7 tillers, except for Sumenep that has only 3-4 seedlings. For wet weight and dry weight per clump in the varieties applied to Trichoderma, the weight per clump is higher than those without Trichoderma, and yet wet weight and dry weight for Batu Ijo without Trichoderma application are relatively similar.
Lesson learned from the development of sustainable rice farming in peatland
Authors: Fawzi N I , Qurani I Z
Published: May 2021

Future food production is expected to meet the capacity in providing food for 9.7 billion people in the world by 2050. As the population rises, the demand for rice cropping areas in Indonesia will double to approximately 16.5 million ha by 2040. Deploying arable land intensification alone would hardly fill the gap. In Indonesia, around 140,000 – 187,000 hectares of agriculture areas have been lost due to residential or industrial purposes every year, especially in Java Island. This research attempted to explore the viable farming method to improve rice production in peatland which has the potential to be cultivated as arable land. Three main issues hindered the development of rice growth: acidic soil and water, irrigation, and rice variety adaptation. Despite these constraints, the experiments in Pulau Burung District, Indragiri Hilir Regency, Riau using rice varieties Mekongga, IR 64, and Cilamaya Muncul managed to yield an average up to 4-ton/ha of rice grain. This number is close to the Indonesian average productivity of 5-ton/ha. In practice, the experiments leverage on an integrated water resource management and the selected ameliorant. The yield range in peatland is often limited by productivity factors such as pest, fertilizer, water, next to the cost of providing ameliorant. By further developing the practice, sustainable rice farming can contribute in securing staple food production.
Olfactory Response of Plutella xylostella (Lepidoptera: Yponomeutidae) Adults to Refugia Plant
Authors: Asmoro P P , Dadang  , Pudjianto  , Winasa I W
Published: May 2021

Selection of refugia plants is an important step when engineering the agroecological system. The refugia plants can be repellent or attractant to insect pests and in many species the role of each plant can be studied using the olfactory responses of the insect to volatile chemical cues emitted by the plant. The objective of this study was to determine the olfactory response of Plutella xylostella (Lepidoptera: Yponomeutidae) adults to several refugia plant candidates. Y-tube olfactometer tests were used to determine responses of P. xylostella to candidate plant species including: Ageratum conyzoides, Galinsoga parviflora, Synedrella nodiflora, Sphagneticola trilobata, Brassica rapa, Rorippa indica, Arachis pintoi, Ocimum basilicum, Apium graveolens, and Portulaca oleracea. Olfactory choice tests were conducted to compare preferences of insect. The results showed that R. indica, G. parviflora, and S. trilobata flowers attracted P. xylostella. R. indica and B. rapa leaves had high attractiveness for P. xylostella adults. At the same time, the A. graveolens, A. conyzoides, and O. basilicum leaves showed potential repellency. The conclusions of this study are R. indica and B. rapa have potential for use as trap crops, while A. graveolens, O. basilicum, and A. conyzoides have potential as repellent plants. Further study is necessary to test the olfactory response of P. xylostella’s natural enemies to these refugia plants.