bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optical bistability in reflection of the laser pulse in a 1D photonic crystal doped with four-level InGaN/GaN quantum dots
Authors: Shiri Jalil , Khalilzadeh Javad , Asadpour Seyyed Hossein 
Published: February 2021

Abstract
The present study aimed to evaluate the optical properties of 1D photonic crystal (PC) with a defect layer doped by four-level InGaN/GaN quantum dots. Transient and steady-state behavior of the medium completely relies on the intensities and relative phases of coherent coupling fields. In addition, the transient absorption–dispersion spectra of 1DPC can be easily adjusted by choosing the controllable parameters properly. Furthermore, the transmitted and reflected light pulses at

λ
=
1.55
μ
m

(long wavelength) can be tuned by controlling the Rabi frequencies of applied light due to their potential applications in all-optical systems. Furthermore, the effect of relative phase between applied fields on the light propagation was evaluated through the medium. In addition, all-optical switching time was found for subluminal/superluminal and absorption/transmission of light propagation. The required switching time ranges between 2–7 ps. The proposed model may provide some new possibilities for technological applications in optoelectronics and solid-state quantum information science and systems due to large applications in signal processing.
High-efficiency continuous-variable quantum digital signature protocol for signing multi-bit messages
Authors: Zhao Wei , Shi Ronghua , Ruan Xinchao 
Published: February 2021

Abstract
A quantum digital signature (QDS) is guaranteed by the laws of quantum physics and can provide unconditional security to authenticate classical messages. Previous QDS protocols that shared secret keys could be realized using discrete-variable quantum key distribution (DV-QKD), for which the DV-QKD relied on extreme requirements like single-photon detection and extremely weak pulses of light. QDS protocols are mainly focused on how to sign a one-bit message rather than multi-bit messages. In this paper, we present a continuous-variable quantum digital signature (CV-QDS) protocol for signing multi-bit messages. The CV-QDS protocol has better compatibility with existing communication systems and the encoding strategy for multi-bit messages is simpler than before. We hope the continuous-variable protocol could further improve the performance of QDS.
Voltage-dependent plasticity and image Boolean operations realized in a WO
x
-based memristive synapse
Authors: Shi Jiajuan , Lin Ya , Zeng Tao , Wang Zhongqiang , Zhao Xiaoning , Xu Haiyang , Liu Yichun 
Published: February 2021

Abstract
The development of electronic devices that possess the functionality of biological synapses is a crucial step towards neuromorphic computing. In this work, we present a WO
x
-based memristive device that can emulate voltage-dependent synaptic plasticity. By adjusting the amplitude of the applied voltage, we were able to reproduce short-term plasticity (STP) and the transition from STP to long-term potentiation. The stimulation with high intensity induced long-term enhancement of conductance without any decay process, thus representing a permanent memory behavior. Moreover, the image Boolean operations (including intersection, subtraction, and union) were also demonstrated in the memristive synapse array based on the above voltage-dependent plasticity. The experimental achievements of this study provide a new insight into the successful mimicry of essential characteristics of synaptic behaviors.
On the equivalence of self-consistent equations for nonuniform liquids: a unified description of the various modifications
Authors: Frusawa Hiroshi 
Published: February 2021

Abstract
A variety of self-consistent (SC) equations have been proposed for non-uniform states of liquid particles under external fields, including adsorbed states at solid substrates and confined states in pores. External fields represent not only confining geometries but also fixed solutes. We consider SC equations ranging from the modified Poisson–Boltzmann equations for the Coulomb potential to the hydrostatic linear response equation for the equilibrium density distribution of Lennard-Jones fluids. Here, we present a unified equation that explains the apparent diversity of previous forms and proves the equivalence of various SC equations. This unified description of SC equations is obtained from a hybrid method combining the conventional density functional theory and statistical field theory. The Gaussian approximation of density fluctuations around a mean-field distribution is performed based on the developed hybrid framework, allowing us to derive a novel form of the grand-potential density functional that provides the unified SC equation for equilibrium density.
Out-of-equilibrium Frenkel–Kontorova model
Authors: Imparato A 
Published: February 2021

Abstract
A 1D model of interacting particles moving over a periodic substrate and in a position dependent temperature profile is considered. When the substrate and the temperature profile are spatially asymmetric a centre-of-mass velocity develops, corresponding to a directed transport of the chain. This autonomous system can thus transform heath currents into motion. The model parameters can be tuned such that the particles exhibit a crossover from an ordered configuration on the substrate to a disordered one, the maximal motor effect being reached in such a disordered phase. In this case the manybody motor outperforms the single motor system, showing the great importance of collective effects in microscopic thermal devices. Such collective effects represent thus a free resource that can be exploited to enhance the dynamic and thermodynamic performances in microscopic machines.
Support for the personalization of master’s studies based on a fuzzy competency model (on the example of data analysis disciplines)
Authors: Gaibova T V 
Published: February 2021

Abstract
Competence models for evaluating important teaching tools for personalizing educational content. This problem is of particular importance for studying in the master’s program, the teacher of each discipline needs the diversity of the educational trajectories of the master’s students and create an adaptive educational environment for both those who deepen their profiling, continuing their education in the previously chosen direction of training, and for those who have changed the vector of professional development. The aim is to demonstrate a fuzzy model for assessing competence using the example of this organization of training in data analysis. It is developed on the basis of the integration of cognitive modeling and fuzzy logic and is distinguished by the ability to analyze the mutual influence of the concepts of the considered area of knowledge of the target level of learning and is the basis for determining the area of acceptable educational trajectories. The implementation of the proposed model will provide high-quality personalization of semi-structured educational content. The author analyzed the modern skill sets of specialists in the field of data science and analytics, as well as methods and tools for competence assessment in the context of learning adaptation. The requirements for the developed concept of soft learning in the context of personalization of learning in the master’s program are determined, the structure of a fuzzy cognitive map is proposed, which allows one to assess the semi-structured competencies of various groups and determine the priority of mastering the concept of the proposed educational content. The proposed approach will make it possible to systematize the process of identifying permissible educational trajectories at the discipline level, depending on the available knowledge and accumulated professional experience, as well as on the student’s career aspirations, thereby expanding the range of possible educational strategies and increasing the level of organization of the educational process on the part of the teacher and the level of self-organization on the part student.
Methods for implementing the concept of “Smart City” based on Bayesian Intelligent Technologies
Authors: Prokopchina S V 
Published: February 2021

Abstract
Information systems based on Bayesian intelligent technologies make it possible to implement monitoring, control and management tools within the framework of the “Smart City” concept. Such tasks are connected, on the one hand, with the processing of large arrays of various types of information, on the other hand, with difficult conditions for solving problems due to uncertainty. This article discusses the methodological aspects of the application of the regularizing Bayesian approach and Bayesian technologies focused on uncertainty and information processing both in the form of data and in the form of various knowledge. It is shown that such systems can be implemented in the form of intelligent cognitive networks with the processing of different types of measurement, statistical, reporting information, integrated with the assessments and decisions of experts and specialists. Examples of using the proposed approach and technologies for solving applied problems of digitalization of urban economy are given.
Modelling of the stress-strain state of a transport tunnel under load as a measure to reduce operational risks to transportation facilities
Authors: Ivanitskaya N V , Baybulov A K , Safronchuk M V 
Published: February 2021

Abstract
In many countries economic policy has been paying increasing attention to the modernization and development of transport infrastructure as a measure of macroeconomic stimulation.Tunnels as an important component of transport infrastructure save a lot of logistical costs.It stimulates increasing freight and passenger traffic as well as the risks of the consequences of unforeseen overloads.The objective of the paper is to suggest the way to reduce operational risks of unforeseen moving load by modeling of the stress-strain state of a transport tunnel under growing load for different conditions and geophysical parameters.
The article presents the results of a study of the stress-strain state (SSS) of a transport tunnel exposed to a mobile surface load. Numerical experiments carried out in the ANSYS software package made it possible to obtain diagrams showing the distribution of equivalent stresses (von Mises - stresses) according to the finite element model of the tunnel. The research results give grounds to assert that from external factors the stress state of the tunnel is mainly influenced by the distance to the moving load. The results obtained make it possible to predict in advance the parameters of the stress-strain state in the near-contour area of the tunnel and use the results in the subsequent design of underground facilities, as well as to increase their reliability and operational safety.
This investigation gives an opportunity not only to reduce operational risks at the design stage, but to choose an optimal balance between investigation costs and benefits of safety usage period prolongation.
Combining Bayesian and logical-probabilistic approaches for fuzzy inference systems implementation
Authors: Kozhomberdieva G I , Burakov D P 
Published: February 2021

Abstract
In the paper, an original way to implement the fuzzy inference systems is considered. The proposed fuzzy inference model is based on usage of conjunction of probabilistic logic and Bayes’ formula at inference stage. For that preconditions of all the specified fuzzy production rules are transformed to the set of probabilistic functions. As the input probabilities, the values of membership functions of input linguistic variables terms are used. At that given set of production rules is reduced in the way that number of rules will be equal to number of terms of output linguistic variables. For that logic expressions of production preconditions are transformed to orthogonal DNFs. Calculated probability values are used as conditional probabilities in determining the posterior distributions on the set of hypotheses corresponding to values of the output linguistic variables. To determine the posterior probability distribution, we use the formula based on the Bayes’ formula. These posterior distributions are used at defuzzification stage for determining final output variable values, because they are calculated as expected values of corresponding random variables. The program implementation has allowed to estimate the proposed model effectiveness and to compare its results with results of traditionally used Mamdani and Sugeno fuzzy inference algorithms.
Application of Bayesian approach and probability theory for calculating territorial risk and zoning on urban area
Authors: Tunakova Y A , Shagidullin A R , Valiev V S , Galimova A R 
Published: February 2021

Abstract
The article describes a new algorithm for assessing territorial risk. The risk in the algorithm is calculated as the ratio of the prior and posterior probabilities of an unfavorable (risk) event. An event is an excess of the threshold content of toxicants in a certain area of space, taking into account how often this event occurred in all other areas of space. This can be used for zoning an urbanized area. We used a probabilistic safety assessment (PSA) apparatus based on hazard modelling and a scenario-based approach. Such an apparatus does not analyse certain integral characteristics of the process, but all possible states in a given time section at the same time, forming a probabilistic model. The probabilistic approach ensures the accuracy and realism of assessments of the state of the environment of an urbanized area that are unattainable for deterministic methods and, in addition, allows you to take into account the cumulative effect of multiple sources of uncertainty. Using the probabilistic method and assessing the level of risks allows you to broadcast complex scientific information in an accessible format to people making environmental decisions. Risk is not an absolute but a relative category. It is heterogeneous in both time and space. Therefore, it can be used when zoning the environment, especially since the parameters that are used to calculate risk very often form the same data arrays necessary for classifying and zoning spatial non-uniformity of the system in general. After analyzing various approaches, we came to the conclusion that for a given time period the probability of an adverse event will be calculated more accurately if we calculate not using the classical formula (the number of cases per time interval), but in the form of the ratio of the posterior and prior probabilities. This takes into account the risk in a certain area of space and correlates with the frequency of the same event in all other areas. To assess the likelihood of polymetallic pollution of environmental objects in an urbanized area with its subsequent zoning, we considered the variability of the metal content in environmental objects. Based on the probabilities that metal concentrations exceeded their threshold values, the territorial relative risk was calculated and zoning of the urbanized territory was carried out. Testing of the considered approaches was carried out in the territory of Kazan on the basis of an array of data of experimental measurements on the content of metals in environmental objects. For sampling, 170 points were selected across the territory of the city of Kazan, which are under the influence of stationary and mobile sources of the influx of metals into the urbanized territory. The probability distribution of exceeding the threshold level of metal content in environmental objects in the territory of Kazan is shown cartographically.
Using semantic field model to create information search engines
Authors: Sachkov V E , Zhukov D O , Andrianova E G 
Published: February 2021

Abstract
In the web infrastructure of information search, the use of semantic methods is considered to be a new round of the technology development. With the emergence of big data, a relevant issue is processing large amounts of data to extract valuable knowledge, especially for text files in natural language. Practice shows that traditional natural language search engines cannot always extract the necessary data from such data sets, as they do not take into account several subtle aspects of the language used in human speech. To solve this problem, the possibilities of using semantic search engines for text processing are being explored. This paper discusses the possible use of the semantic field model developed by the authors, to create a semantic search engine. Experiments have shown that using this model can improve the search accuracy. This model can be additionally used in creation of interactive dialogue systems.
Influence of rainfall dynamics uncertainty on sensitivity analyses results in hydrodynamic models of large urbanised catchments
Authors: Majewska M , Wałek G , Ciupa T , Musz-Pomorska A , Widomski M K 
Published: February 2021

Abstract
This paper presents an analysis method of rainfall uncertainty influence on the variability of modelled runoff from a municipal catchment. The model of 41.75 km2 basin prepared in SWMM 5.0 software was used in this study. The developed model consisted of 120 sub-catchments of area 5-100 ha and terrain slope 0.2 – 6%. The share of the impervious surface area of sub-catchments was in the range of 1 – 80%. The model was preliminary calibrated basing on measurement data for six rainfall-runoff events at four measuring cross-sections. To allow assessment of time-related rainfall intensity variability influence on maximal flow values registered at measuring cross-sections, the length of time step was changed by a division of registered data values on 30 minutes periods. The uncertainty parameterisation was performed for analysed rainfall events (resolution 30 minutes) by introduction the subsequent values of θ = {0.3; 0.4; 0.5; 0.6; 0.7}. Thus, it was assumed that for θ = 0.3, 30% of hourly rainfall dropped during the first 30 minutes, the remaining 70% during the next time step, etc. For the assumed θ = 0.3 – 0.7 values influence calculations of calibrated parameters variability (retention depth of impervious, impervious surfaces, the roughness of impervious surfaces, retention depth of pervious surfaces, and roughness of pervious surfaces) on modelled values of maximal flows at measuring cross-sections were performed. In order to supplement the analysis, the influence of impervious terrains spatial variability at measuring cross-sections on determined dynamics of maximal flows concerning SWMM 5.0 calibrated parameter values was assessed.
Structural factors influence on strength properties of S235JR steel welded joints
Authors: Miturska I , Rudawska A 
Published: February 2021

Abstract
The paper presents the results of strength tests of welded joints of S235JR structural steel. Welded joints of various geometries were made: butt joints, overlap joints with a single weld, overlap joints with double welds, overlap joints with spot welds, overlap joints with hole welds, and double-flanged seam. The strength tests carried out made it possible to determine the destructive force. Eight joints of each type were made. Based on the results obtained, a statistical analysis was carried out to determine the influence of structural factors on the strength of welded joints and to assess the repeatability of the process of making joints of a given type. This analysis allows verifying which of the tested geometries of welded joints are the most strength and stability, which is especially important when designing new structures or planning renovation of existing structures. The analysis showed that the highest strength as well as the highest repeatability was obtained in the case of overlapped joints with double welds – destructive force at 37 367 MPa. The lowest strength was characterised by double-flanged seam – destructive force 8 603 MPa.
Neural modelling of solar radiation variability
Authors: Ronkiewicz T , Aleksiejuk-Gawron J , Awtoniuk M , Kurek J 
Published: February 2021

Abstract
Artificial neural networks are increasingly used in engineering and technical sciences, especially to solve problems under process uncertainty. The mathematical model presented in this article describes cloud variability. The application of the model can increase the efficiency of solar systems because the response time of the solar panel to changing weather conditions is crucial. The model involves an artificial neural network that serves to determine the degree of daily cloud coverage based on three data – the month, daily solar radiation sum and total harmonic distortion factor (THD). The THD factor is determined for daily solar radiation courses using a Fast Fourier Transform. Approaching the daily variability of solar radiation as a sine wave allows employing the THD factor in an unconventional and innovative way. The modelling data have been derived from the measurements of the meteorological station of the Institute of Mechanical Engineering of the Warsaw University of Life Sciences. MATLAB Software (2019a) was used for data processing and network modelling. The model is verified using the mean square error. The performed analysis provides promising results and conclusions.
Numerical modelling of forming load on pre-stressed dies
Authors: Bulzak T , Wójcik Ł , Szala M 
Published: February 2021

Abstract
The article presents a method of numerical modelling of the load on pre-stressed dies. Numerical modelling was performed in two stages. In the first stage, a simulation of the process of extruding with stiff tools was performed. In the second stage, load on the tools obtained in the first stage was implemented and strength tests of the dies were performed. Four construction variants of the tools made of steel and sintered carbide were analysed. In the first set of tools, a monolithic die with a container was used. In the second set, a die and a divided container were applied. In the third set, a die and a container stressed with a singular ring were used. In the last set, a die with a container stressed with two rings was analysed. As a result, distributions of reduced, radial, tangential, and axial stresses were presented for various construction variants. Die and container made of sintered carbide stressed with two rings ensure the necessary strength of tools and correct progression of the process.
The crack surface morphology investigation of S355J2 steel after bending-torsion fatigue
Authors: Macek W , Marciniak Z , Branco R , Szala M , Rehmus-Forc A 
Published: February 2021

AbstractThe paper describes the analysis of crack surface morphology of S355J2 steel specimens after bending-torsion fatigue. These experimental investigations of the surface topography were carried out using the focus variation microscope, an optical 3D measurement device. Selected results of measured fracture surfaces for S355J2 steel were analysed according to the surface texture ISO 25178 standard. Differences in roughness values for different loadings were demonstrated. For profile Rx and areal Sx parameters, characteristic relationships of fracture zones have been demonstrated. It has been shown that roughness profile Ra for the rupture area is higher than for the propagation area, as well as increases after both the LCF and HCF tests and increases with the torsional loading level. However, Sa in the propagation area increases and the rupture area decreases.