bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pseudospectral method for solving fractional Sturm-Liouville problem using Chebyshev cardinal functions
Authors: Afarideh Alireza , Dastmalchi Saei Farhad , Lakestani Mehrdad , Nemati Saray Behzad 
Published: November 2021

Abstract
This work deals with the pseudospectral method to solve the Sturm-Liouville eigenvalue problems with Caputo fractional derivative using Chebyshev cardinal functions. The method is based on reducing the problem to a weakly singular Volterra integrodifferential equation. Then, using the matrices obtained from the representation of the fractional integration operator and derivative operator based on Chebyshev cardinal functions, the equation becomes an algebraic system. To get the eigenvalues, we find the roots of the characteristics polynomial of the coefficients matrix. We have proved the convergence of the proposed method. To illustrate the ability and accuracy of the method, some numerical examples are presented.
Dynamics of quantum correlations in a qubit-qutrit spin system under random telegraph noise
Authors: Benabdallah Fadwa , Zad Hamid Arian , Daoud Mohammed , Ananikian Nerses 
Published: November 2021

Abstract
We study the dimensionless time evolution of the logarithmic negativity and geometric quantum discord of a qubit-qutrit XXX spin model under the both Markovian and non-Markovian noise channels. We find that at a special temperature interval the quantum entanglement based on the logarithmic negativity reveals entanglement sudden deaths together with revivals. The revival phenomenon is due to the non-Markovianity resulting from the feedback effect of the environment. At high temperatures, the scenario of death and revival disappears. The geometric quantum discord evolves alternatively versus time elapsing with damped amplitudes until the system reaches steady state. It is demonstrated that the dynamics of entanglement negativity undergoes substantial changes by varying temperature, and it is much more fragile against the temperature rather than the geometric quantum discord. The real complex heterodinuclear [Ni(dpt)(H2O)Cu(pba)] · 2H2O [with pba = 1,3-propylenebis(oxamato) and dpt = bis-(3-aminopropyl)amine] is an experimental representative of our considered bipartite qubit-qutrit system that may show remarkable entanglement deaths and revivals at relatively high temperatures and high magnetic field that is comparable with the strength of the exchange interaction J between Cu+2 and Ni+2 ions, i.e., k

B

T ≈ J and μ

B

B ≈ J.
Solitons propagation dynamics in a saturable PT-symmetric fractional medium
Authors: Haji Taghi Tehrani D , Solaimani M , Ghalandari Mahboubeh , Babayar-Razlighi B 
Published: November 2021

Abstract
In the current research, the propagation of solitons in a saturable PT-symmetric fractional system is studied by solving nonlinear fractional Schrödinger equation. Three numerical methods are employed for this purpose, namely Monte Carlo based Euler–Lagrange variational schema, split-step method, and extrapolation approach. The results show good agreement and accuracy. The effect of different parameters such as potential depth, Levy indices, and saturation parameter, on the physical properties of the systems such as maximum intensity and soliton width oscillations are considered.
Design and physics basis for the upcoming DIII-D SAS-VW campaign to quantify tungsten leakage and transport in a new slot divertor geometry
Authors: Abrams T , Sinclair G , Nichols J H , Unterberg E A , Donovan D C , Duran J , Elder J D , Glass F , Grierson B A , Guo H Y , Hall T , Ma X , Maurizio R , McLean A G , Murphy C , Nguyen R , Rudakov D L , Stangeby P C , Thomas D M , Zamperini S A 
Published: November 2021

Abstract
A set of experiments are planned to exploit the high SOL collisionality enabled by a tightly baffled slot divertor geometry to suppress tungsten leakage in DIII-D. A toroidal row of graphite tiles from the Small Angle Slot (SAS) divertor is being coated with 10–15 μm of tungsten. New spectroscopic viewing chords with in-vacuo optics will measure the W gross erosion source from the divertor surface with high spatial and temporal resolution. In parallel, the bottom of the SAS divertor is changed from a flat to a ‘V’ shape. New SOLPS-ITER/DIVIMP simulations conducted with drifts using the planned ‘V’ shape predict a substantial reduction in W sourcing and SOL accumulation in either B × ∇B direction relative to either the old SAS divertor shape or the open, lower divertor. Dedicated studies are planned to carefully characterize the level of W sourcing, leakage, and scrape-off-layer (SOL) accumulation in DIII-D over a wide range of plasma scenarios. Various actuators will be assessed for their efficacy in further reducing high-Z impurity sources and leakage from the slot divertor geometry. This coupled code-experiment validation effort will be used to stress-test physics models and build confidence in extrapolations to advanced, high-Z divertor geometries for next-step devices.
The EMU view of the Large Magellanic Cloud: troubles for sub-TeV WIMPs
Authors: Regis Marco , Reynoso-Cordova Javier , Filipović Miroslav D. , Brüggen Marcus , Carretti Ettore , Collier Jordan , Hopkins Andrew M. , Lenc Emil , Maio Umberto , Marvil Joshua R. , Norris Ray P. , Vernstrom Tessa 
Published: November 2021

Abstract
We present a radio search for WIMP dark matter in the Large Magellanic Cloud (LMC).
We make use of a recent deep image of the LMC obtained from observations of the Australian Square Kilometre Array Pathfinder (ASKAP), and processed as part of the Evolutionary Map of the Universe (EMU) survey.
LMC is an extremely promising target for WIMP searches at radio frequencies because of the large J-factor and the presence of a substantial magnetic field.
We detect no evidence for emission arising from WIMP annihilations and derive stringent bounds on the annihilation rate as a function of the WIMP mass, for different annihilation channels. This work excludes the thermal cross section for masses below 480 GeV and annihilation into quarks.
Closed-loop control of a prosthetic finger via evoked proprioceptive information
Authors: Vargas Luis , Huang He (Helen) , Zhu Yong , Hu Xiaogang 
Published: November 2021

Abstract

Objective. Proprioceptive information plays an important role for recognizing and coordinating our limb’s static and dynamic states relative to our body or the environment. In this study, we determined how artificially evoked proprioceptive feedback affected the continuous control of a prosthetic finger. Approach. We elicited proprioceptive information regarding the joint static position and dynamic movement of a prosthetic finger via a vibrotactor array placed around the subject’s upper arm. Myoelectric signals of the finger flexor and extensor muscles were used to control the prosthesis, with or without the evoked proprioceptive feedback. Two control modes were evaluated: the myoelectric signal amplitudes were continuously mapped to either the position or the velocity of the prosthetic joint. Main results. Our results showed that the evoked proprioceptive information improved the control accuracy of the joint angle, with comparable performance in the position- and velocity-control conditions. However, greater angle variability was prominent during position-control than velocity-control. Without the proprioceptive feedback, the position-control tended to show a smaller angle error than the velocity-control condition. Significance. Our findings suggest that closed-loop control of a prosthetic device can potentially be achieved using non-invasive evoked proprioceptive feedback delivered to intact participants. Moreover, the evoked sensory information was integrated during myoelectric control effectively for both control strategies. The outcomes can facilitate our understanding of the sensorimotor integration process during human-machine interactions, which can potentially promote fine control of prosthetic hands.
Alfvén eigenmode classification based on ECE diagnostics at DIII-D using deep recurrent neural networks
Authors: Jalalvand Azarakhsh , Kaptanoglu Alan A. , Garcia Alvin V. , Nelson Andrew O. , Abbate Joseph , Austin Max E. , Verdoolaege Geert , Brunton Steven L. , Heidbrink William W. , Kolemen Egemen 
Published: November 2021

Abstract
Modern tokamaks have achieved significant fusion production, but further progress towards steady-state operation has been stymied by a host of kinetic and MHD instabilities. Control and identification of these instabilities is often complicated, warranting the application of data-driven methods to complement and improve physical understanding. In particular, Alfvén eigenmodes are a class of ubiquitous mixed kinetic and MHD instabilities that are important to identify and control because they can lead to loss of confinement and potential damage to the walls of a plasma device. In the present work, we use reservoir computing networks to classify Alfvén eigenmodes in a large labeled database of DIII-D discharges, covering a broad range of operational parameter space. Despite the large parameter space, we show excellent classification and prediction performance, with an average hit rate of 91% and false alarm ratio of 7%, indicating promise for future implementation with additional diagnostic data and consolidation into a real-time control strategy.
Evaluating the Effectiveness of an Intrusion Detection System Based on Matrix Games and Fuzzy Sets
Authors: Vilkov V B , Dergachev A I , Chernykh A K , Abu-Khasan M S 
Published: November 2021

Abstract
We consider a problem formulated as a matrix game in which the gain of officials using a specific intrusion detection system (criminal actions) of intruders (player 1) is the probability of timely detection of these criminal actions (player 2). As a rule, it is not possible to unambiguously set the probability of timely detection of criminal actions, so it is proposed to use the apparatus of fuzzy set theory to evaluate it. Reviewed and discussed the basic concepts of fuzzy set theory, and an example of practical application of this theory to assess the efficiency of the detection system of criminal damage. Application of fuzzy set theory in assessing the possible actions of an attacker can detect existing vulnerabilities in information security of automated systems continue to spend improving the detection of criminal acts (hackers) to prevent the possibility of applying economic and other damage to the company.
Efficiency of Installation of an Additional Gas-Air Heat Exchanger When Operating a Steam Boiler on Gas and Liquid Fuel
Authors: Bakirov F , Ibragimov E 
Published: November 2021

Abstract
The article presents the results of calculating the efficiency of reconstruction of the gas and air paths of a steam boiler when working on gas and liquid fuel due to the installation of additional gas-air heat exchangers. Due to the utilization of the thermal energy of the flue gases in the newly installed heat exchangers, the air is heated in front of the boiler air heaters and the fuel efficiency is increased by increasing the boiler efficiency. The increase in the efficiency of the "gross" boiler during the operation of the considered TGM-84 boiler on fuel oil with an average annual operating mode was 2.81 %. The flue gas temperature after the boiler air heaters was 178 °C, and the air temperature at the inlet to the air heaters was 99 °C at the average annual load of the boiler, which ensures an almost corrosion-free operation of the air heater packing. It is revealed that when the liquid fuel boilers, installation of new heat exchangers and their strapping on the side of the air and flue gas has a shorter payback period than the boiler gas fired. The simple payback period of the considered technical solution was 6,82 years when working on gas fuel and 1,35 years when working on liquid fuel.
Adaptive Threshold Scheme for Pulse Detection under Condition of Background Nonstationary Noise
Authors: Shcherbina A O , Lukovenkova O O , Solodchuk A A 
Published: November 2021

Abstract
The paper describes a new adaptive threshold scheme for detecting pulses in high-frequency signals against a background of non-stationary noise. The result of the scheme operation is to determine the pulse boundaries by comparing the signal amplitude-time parameters with the threshold. The threshold value is calculated in non-overlapping windows of fixed length and depends only on the background noise level. The detected pulses undergo additional shape checking, taking into account their characteristics. The parameters of the algorithms for detecting pulses and checking their shape can be adjusted for any type of high-frequency pulse signals. This threshold scheme is tuned to detect pulses in high frequency geoacoustic emission signals. The results of the scheme operation on an artificial signal and on fragments of a geoacoustic signal are given, a comparison is made between the proposed scheme and the previously used (outdated) one. The new threshold scheme proposed by the authors is less sensitive to the choice of the initial threshold value and it is more stable in operation. When processing 15-minute fragments of a geoacoustic signal, the new scheme correctly detects, on average, 5 times more pulses.
Development and Application of Convolutional Neural Network for the Recognition of Objects in the Scheme of Electric Grid
Authors: Rezaeva M A , Semendyaev R Y 
Published: November 2021

Abstract
One of the current design problems in the electric power industry is the labor intensity of synthesizing mathematical models to calculate the electrical modes of the network. It takes a lot of time to compose a detailed model of a large power system based on circuit diagram data. To simplify, speed up, and automate the data input, a convolutional neural network is proposed. In this paper the definition of convolutional neural network is given, its elements are described, the architecture of neural network is developed, the accuracy of its work on the schematic diagrams of various power systems is 0.84.
Graphical Analysis of Day - Night Temperature Difference by Interpolation and Approximation Methods for the Energy Converter of the Environment
Authors: Chelukhin V , Aung Piei Zon 
Published: November 2021

Abstract
Today, a lot of attention is paid to the search for environmentally friendly renewable energy sources. The most frequently considered such energy sources are wind energy, solar technology, the use of the energy of sea waves and biomass.
Each of them has a drawback that prevents its widespread adoption. For example, wind farms create noise during their operation, are rigidly tied to the place where there are acceptable wind resources.
To date, an energy converter has been developed, which works on the basis of the use of the ambient temperature difference during the day - the temperature is high during the day, and the temperature decreases at nightAs a rule, this temperature difference is in the range of about 5-9 degrees, although there are regions in which this difference is much higher, for example, in winter in Urengoy it can reach up to 30 degrees. An energy converter of this type is considered in works / 1-2/.
The basis of the operation of such a converter is the change in the linear size of bodies, for example, plexiglass, with a change in temperature. When the temperature rises during the day, when the temperature is high, the rod lengthens, while at night, when the temperature is low, the linear dimensions of the rod decrease. This is exactly what is used to obtain energy through the use of a container. A conventional capacitor is used, one plate of which is fixed, the second plate of this capacitor is movable and connected to a dielectric plexiglass rod. When the temperature changes, for example, at a high temperature, the rod lengthens, the plates of the container come closer and the capacity will be maximum. At night, when the temperature decreases, the plexiglass rod is shortened, the plate moves away and the capacity decreases.
If, at maximum capacity, the capacitor is charged and disconnected from the source, then the charge on it will be constant. At night, when the rod shrinks its linear dimensions, the movable plate moves away, the capacity falls. Since the charge on the container is constant, the voltage increases and we get an increase in energy, which is obtained from the day-night temperature difference and the change in the linear dimensions of the dielectric rod.
Computational Model for Radial Plain Bearing with Non-Circular Bearing Surface Profile and Fusible Coating on Shaft Surface
Authors: Mukutadze M A , Novakovich M V , Zadorozhnaya N S 
Published: November 2021

Abstract
The paper presents a study based upon: a Newtonian fluid flow equation (“thin layer”), a continuity equation, and an equation of the molten-profile radius for a shaft coated with a fusible metal alloy; considering a mechanical energy dissipation rate formula, the authors produced an asymptotic and accurate automodel solution for the zero approximation (melting ignored) and first approximation (adjusted for melting) of a radial plain bearing featuring a fusible metal coating and a bearing profile adapted to the specific friction parameters. The paper further presents analytical dependencies describing the molten surface radius, velocity and pressure fields for zero and first approximation. Besides, it determines the key operating parameters of the frictional couple, the bearing capacity, and the friction. It also shows how the parameters arising from the melting of the surface affect the bearing capacity and friction where the bearing surface profile is adapted to the specific conditions of friction.
Analysis and Development Potential of Predictive Models for Energy Flows of Autonomous Hybrid Energy Systems
Authors: Berdonosov V D , Vasilev G V , Zhivotova A A 
Published: November 2021

Abstract
The article is devoted to the analysis and development potential for predictive models of energy flows of autonomous hybrid energy systems. The article considers the results of the analysis in the form of a morphological table and TRIZ–evolutionary map. The research defined the most promising in predicting energy flows are hybrid models that include more than one architecture. For example, DCNN + LSTM or MLP + LS–SVR. The authors intend to continue research in the direction of creating predictive models of wind energy flows for autonomous hybrid energy systems.
Practical Aspects of Modernization of Electrical Equipment of the Substation
Authors: Bodrug N S , Skripko O V 
Published: November 2021

Abstract
Currently, one of the important problems for domestic energy is the replacement of an outdated fleet of equipment at substations of electric power systems (EPS). The paper addressed the issue of upgrading the "Ice" substation in part of the selection of switches, checking the reliability of switches and the reliability of the substation in general. The substation characteristic is given, the changes in the main scheme of the substation electrical connections are substantiated, switches for all substation voltages are selected according to the current short circuit currents. To assess the degree of reliability of the selected switches, the substation is determined by their probability of refusal. Based on the assessment of the likelihood of failures and other equipment for the substation, the estimated time of trouble-free operation was determined, the average time of trouble-free operation and the average substation recovery time.
DDoS Protection Method for Servers
Authors: Fedorov V Kh , Balenko E G , Vershennik E V , Zakalkin P V 
Published: November 2021

Abstract
Cyberspace, a global artificial space, has emerged and become part of all human activities, which exposes communication network elements, in particular service servers, to attacks, whether from individual hackers and cyberterrorists or from organized communities. Denial-of-service or DDoS attacks are the most common type. These are intended solely to cause a denial of service in various information systems, including service servers. This paper presents a method that can improve protection of servers that provide various resources (services) by reasonable management of filter rules and IP address lists.
Four-dimensional Integral Model of Dry Friction on the Example of Wheel Movement
Authors: Salimov M S , Saypulaev G R , Merkuriev I V 
Published: November 2021

Abstract
A four-dimensional model of dry friction in the interaction of a solid wheel and a horizontal rough surface is investigated. It is assumed that there is no separation between the wheel and the horizontal surface. The movement of the body occurs in conditions of combined dynamics, when in addition to the sliding movement, the body participates in spinning and rolling. The equation of motion of the wheel is compiled using the Appel equation.
The resulting model of sliding, spinning, and rolling friction is given for the case where the contact area is a circle. The cumbersome integral expressions were replaced by fractional-linear Pade approximations. Pade approximations accurately describe the behavior of the components of the friction model. A mathematical model is proposed that describes the simultaneous sliding, spinning and rolling of a solid wheel. The dependences of the parallel and perpendicular components of the friction force and the torque of the spinning friction were ploted with respect to the parameter that characterizes the movement of the wheel. Comparisons of the integral friction model and the model based on Pade approximations are presented. The results of the comparison showed a qualitative correspondence of the models. After obtaining the equation of motion, the simulation of motion at a constant control torque of the wheel is carried out. The graphs allow you to match the logical behavior of the wheel
movement.
Adaptation Parameters of Time Series Models for Forecasting
Authors: Klevtsov S I , Maksimov A V 
Published: November 2021

Abstract
Prospects for using time series to predict changes in technical parameters in real time are considered. The task is to assess the trend dynamics of the parameter. Adaptive polynomial models of the first and second order, based on the method of multiple exponential smoothing, were selected for forecasting. The models have been modified to adapt to the peculiarities of the computing process in the microcontroller. The initial data, the acceleration values in three axes, were obtained using a three-axis accelerometer installed on the vehicle. Comparison of the forecasting results showed that the second-order adaptive polynomial model is generally more preferable from the point of view of the reduced error. Both models can be used to estimate the change in a parameter for an arbitrary number of prediction intervals. The efficiency of using the models for the forecasting problem largely depends on the determination of the adaptation parameters, such as the smoothing constant and the initial estimates of the coefficients of the time series model. The paper considers the features of the behavior of the models and defines the rules for the selection of adaptation parameters depending on the nature of the change in the technical parameter over time.