bluuebunny/crossref_metadata_2025_split huggingface dataset:
Energy savings strategies in Campus Buildings of Athens - Greece
Authors: Tsala S , Koronaki I P 
Published: February 2021

Abstract
Bioclimatic construction has been an important tool for improving the construction of buildings in recent decades. Energy-saving options in buildings include the use of appropriate materials, exposures and the use of alternative power generation systems. In the present work the basic features of the bioclimatic design and study of the energy saving in the buildings of the polytechnic area located in Zografou is presented. In particular, the RETscreen software is used to test energy savings in the buildings of library, mechanical engineering and management building using photovoltaics. It turns out that an important parameter that affects energy saving is the use of the building and the type of photovoltaic used. This is evidenced by the results of RETscreen that in the case of the Library and the Mechanical Engineering building stable photovoltaic have greater energy savings while in the case of the Management building, biaxial photovoltaics produce greater savings.
Comprehensive analysis of the energy supply potential using local types of renewable energy sources
Authors: Tulegenova A A , Kiseleva S V 
Published: February 2021

Abstract
Over the past decade, a steady tendency towards the increasing use of renewable energy sources in the fuel and energy complex of separate countries and regions is observed. Countries that have large hydrocarbon reserves such as the Republic of Kazakhstan are no exception. The main challenges of using renewable energy sources in these countries are related not only to their spatial and temporal variety, but also to the high cost of produced energycomparing to the traditional energy B sources based on hydrocarbon fuel. The solution to the mentioned problems can be achieved by optimizing the use of renewable energy resources, which requires a comprehensive analysis of the territory in terms of physical-geographic conditions and economic factors. The article offers methodological approaches and the results from a spatial analysis of the energy supply potential to consumers in the Republic of Kazakhstan using the cartography tools. It takes into account not only the distribution of resource potential, but also the environmental factors (specially protected natural areas, water conservation zone, etc.) limiting the installation of power plants based on RES, and the energy consumption schedule. Economic factors include the performance of typical power plants based on RES, as well as the present value of potentially generated energy.
Load capacity evaluation for single lap joints applied in the railway vehicles
Authors: Zadorozny T , Szczepanik M 
Published: February 2021

Abstract
The article will present a comparison performed for two different approaches based on the application of Finite Element Method used to overlap joints “HUCK BOM” modeling. For the given geometric form of the joint two different numerical models will be presented and their load capacity will be determined for each of the modeling methodologies. The first methodology where a simplified joint model using beam elements and rigid elements of the RBE2 type will be compared with the second where the initial tension and the influence of friction on the joint load capacity are taking into account. Finally, a comparison of the results obtained with reference to the time of connection modeling and computation will be given.
Global technology trends through patent data analysis
Authors: Sobolieva T O , Holionko N G , Batenko L P , Reshetniak T I 
Published: February 2021

Abstract
The future success of companies directly depends on their innovative activity, research and development of newly technologies. The article examines global technological trends by comparing the number of patent applications in different fields and the degree of development of prominent business areas. These areas are also identified by the highest-ranking positions of the companies in the annual research of innovation in the world. The study highlights the most patentable technological fields, as well as those with the highest average growth of this indicator. The emphasis is made on the regional context of technology patenting and the most active companies in patenting.
Forming the inner flange of a rib by pulsed-magnetic field pressure
Authors: Kurlaev N V , Ahmed Soliman M E , Detinov M B 
Published: February 2021

Abstract
Electromagnetic flanging is a hole-protrusion of parts, a potential technology for forming sheet aluminum metal, provides rigidity, allows positioning and fixing. This paper describes the behavior of a workpiece formed by an electromagnetic flanging, in which the initial blank of annealed aluminum alloy D16AM with a circular precut hole is formed into the first part of the inner flanging (as the first operation of manufacturing a part of the rib). The purpose of this article is to assess the ability of electromagnetic shaping to produce flanges for aircraft components and to study the forming process using numerical simulation. Design of electromagnetic flanges with some elementary geometric shapes, the purpose of which is to clarify a few geometric defects encountered and to propose some solutions. The numerical model of this part was developed in the LS-DYNA computing environment. An example of the numerical simulation of electromagnetic forming of the inner flange of a rib with the obtained shape of the workpiece mesh using a clamp is given. To avoid corrugation at the corner of the workpiece, the magnetic force was increased by reducing the area of the coil adjacent to the corner.
Data-driven system identification and optimal control of an active rotor-bearing system
Authors: Babin A 
Published: February 2021

Abstract
Both diagnostics and control in any piece of rotating machinery is getting more and more attention as computational powers allow storage of big data sets, and we are able to perform approximation, feature extraction and classification of big data. Such transfer from traditional diagnostics and control to machine learning and decision making also makes new ways of system identification based on artificial neural network architectures more attractive as they are more flexible in representing non-linear dynamics. Data-driven linear system identification or non-linear system identification based on artificial neural networks when coupled with optimal control obtained using either traditional or machine learning approaches result in a powerful tool for rotor-bearing system modeling and control that allows using identified model for predictive analysis as well. In the present paper such approach is presented for a rotor system on two journal fluid-film bearings, one of the bearings is equipped with a set of two actuators for feeding pressure control that allows adjustments of rotor position in the bearing. Such adjustments are aimed at decreasing power loss due to friction, so the system is more energy efficient. The presented approach of system identification and modeling can be applied to any similar rotor system.
Welded joint permissible defects influence on the resource of a vertical steel tank under low-cycle loading
Authors: Petrovskaya M V , Konygin S B , Kosareva E A , Kats N G , Levi A A 
Published: February 2021

Abstract
This paper is devoted to the VST determining the residual life issues by the shell welds low-cycle fatigue criterion with permissible defects, taking into account a typical stress concentrator, which has not been fully studied. The fatigue tests results analysis for materials made of low-alloy steel, taking into account welded joints, is given. The Ansys software package has built a model and calculated the stress-strain a vertical steel tank lower belt state for storing oil and oil products VST 20000 with a branch pipe. It is shown that the VST design most dangerous point is in the branch pipe upper part. The maximum stresses and stress amplitudes were obtained in the stub pipe zone and the wornom seam. The cycles to failure performed calculations number showed that the lower VST belt without welded joints wall area withstands 2.4 times more loading cycles than the area with a welded seam and 9.3 times more than the dangerous point in the nozzle stub area.
From technologies to algorithms through the prism of algorithm analysis
Authors: Galkina A I , Grishan I A 
Published: February 2021

Abstract
In anticipation of the predicted transition from the technology economy to the algorithm economy the article is devoted to the analysis of algorithms as an object of intellectual activity of universities registered for the period from 2010 to the present. The selection of information about algorithms and their statistical processing is carried out automatically by the collector_stat program developed by the authors of the article. This article is based on the results of the National Supercomputer Forum (NSCF-2019) and the materials of the joint Fund for electronic resources “Science and education”.
Technological process automation of drinking water deodoration using the methods of machine learning
Authors: Ponomarev S B , Isakov V G , Gorohov M M , Ponomarev D S 
Published: February 2021

Abstract
The study presents an analysis and the possibility of applying machine learning methods to automate the technological process of drinking water deodorization. One of the most actual and popular machine learning methods today is the use of artificial neural networks. Possible neural network structures, activation functions and the number of neural connections were described. The relevance of the introduction of these methods into the system of water management is described.
Hardware implementation of the coding algorithm based on FPGA
Authors: Ibraimov M K , Tynymbayev S T , Park Jongtae , Zhexebay D M , Alimova M A 
Published: February 2021

Abstract
In this article, the efficient implementation multiplier of polynomials irreducible polynomials modulo for cryptographic encryption and decryption using FPGA is presented. For this, the Nexys 4 board based on the Artix-7 Field Programmable Gate Array (FPGA) from Xilinx was chosen. Verilog HDL is used to describe the circuit for reducing a number modulo. The results of a timing simulation of the device are presented in the form of time diagrams for a given 8-bit number, confirming the correct operation of the device. The developed encryption algorithm on the basis of non-positional polynomial notations is intended for software, hardware, and also software and hardware implementation. The main hardware-implemented device in non-positional algorithm of the cryptographic transformation is a device for the multiplication of polynomials irreducible polynomials modulo, which produces routine calculations on data encryption. These mathematical operations are computationally intensive and fundamental arithmetic operations, which are intensively used in many fields such as cryptography, number theory, and finite field arithmetic.
Fuzzy model for assessing the organizational effect of an intelligent process control system
Authors: Smirnov V A , Milova V M , Smirnova M S , Matelenok I V , Zhilnikova N A 
Published: February 2021

Abstract
The article considers the problem of assessing the organizational effect of the functioning of an intelligent decision support system for controlling complex technical systems at the level of a technological control system. The level of organization of activity is used as an indicator of the organizational effect of an intellectual system. To obtain the numerical values of individual indicators of organizational effects, a system of mathematical models is presented that takes into account the specifics of the subject area. Aggregation of heterogeneous indicators to obtain generalized and complex indicators, which are measured on different scales and have a different range of values, is based on a fuzzy classification of parameter values and a fuzzy inference model using the Takagi-Sugeno algorithm. The obtained quantitative assessment of the organizational effect is complemented by a qualitative assessment containing a linguistic description of the level of organization of activities and the degree of expert’s confidence in the result. The considered system of mathematical models for calculating the indicators of the organizational effect can be supplemented depending on the goals, the degree of detail and the depth of analysis and used in the analysis of the effectiveness of existing and future decision support systems and automated information systems at all stages of the life cycle.
Modeling and analysis of fractal growth patterns from the material point
Authors: Teplov A A 
Published: February 2021

Abstract
The growth of fractals from a material point is modeled using single-phase and multi-phase algorithms for linear fractals and polygonal fractal forms. The connection of fractal growth processes with the phenomena of formation in nature is considered. A method for analyzing growth processes and their characteristics is proposed. The growth laws of fractals metric characteristics and their transformation when changing the growth algorithm are revealed. The growth path of fractal points and the distribution of the slope angles of their elements are analyzed. The influence of stochastic fluctuations in the length of fractal elements on the process of its growth is modeled. It is shown that the algorithms and methods used for analyzing growth processes have a great potential for modernization and adaptation to a wide range of tasks.
Modification of the ant colony algorithm for multiversion software application development
Authors: Saramud M V , Kovalev I V , Kovalev D I , Voroshilova A A 
Published: February 2021

Abstract
The article discusses a modification of the ant colony algorithm, which is used to solve the problem of forming the composition of multiversion software with a dynamic architecture. The algorithm was tested for a specific composition of multiversion modules. The graphical dependencies that characterize the changes in the parameters of the cost and reliability of the multiversion software complex with the specified resource constraints are presented.
Control system for nonlinear dynamic processes in a buck converter
Authors: Andriyanov A I 
Published: February 2021

Abstract
The paper deals with a control system for nonlinear dynamic processes in a buck converter based on the target-oriented control and belonging to the class of discrete automatic control systems. The main task of the proposed system is to stabilize the desired dynamic mode, which provides a minimum amplitude of output voltage fluctuation. The author proposes a hardware-software calculation method of the fixed point coordinates in the desired periodic mode, when the average values of state variables are determined by hardware using low-frequency filters, and the fluctuation amplitude of the output physical quantity in the desired dynamic mode is estimated on the basis of analytical expressions. Computer simulation of the proposed system is performed and its efficiency is shown. The proposed approach to estimating the coordinates of the fixed point of the desired mode in real time can be applied to a wide class of DC/DC converters.
Investigation of wear behavior of carbide based coated rolling roll materials under dry and lubricated conditions
Authors: Korkmaz Seyma , Pehlivanoglu Mert , Orak Abdulkadir , Cetin M Huseyin 
Published: February 2021

Abstract
In this study, the effect of TiCN and WC-Co coatings on the tribological performance of spheroidal graphite cast iron materials was investigated by wear tests under dry and lubricated conditions. The mechanical and physical effects of the coating processes were analysed by microhardness measurements and visual methods (SEM, EDX, XRD). The tribological effect of WC-Co and TiCN coated specimens were investigated by ball-on-plate wear tests carried out under dry and boron oil emulsion (5% concentration) conditions at 50 N load and 60 rpm sliding speed parameters. The friction coefficient and wear volume results were obtained to investigate the effect of the coating process and boron oil emulsion on friction and wear behaviour. The wear mechanisms were determined with SEM images obtained from the worn surfaces and surfaces analysed elementally with EDX images. Additionally, surface morphology was examined with surface roughness measurements and 2D–3D topography images. According to the microhardness measurement results, it was observed that the spheroidal graphite cast iron with 290 HV hardness reached 1559 HV with TiCN coating and 1440 HV with WC-Co coating. According to the wear test results, it was determined that TiCN and WC-Co coatings decreased the friction coefficient by 32.51% and 12.80%, respectively. When the effect of boron oil usage compared to dry environmental conditions, it was concluded that the friction coefficient and wear volume decreased by a maximum of 54.80% and 53.70%, respectively. Additionally, the roughness values decreased in the experiments where the boron oil emulsion was used. However, although the TiCN coating improved the surface quality, the WC coating negatively affected the surface quality. Surface form images obtained with 2D and 3D topography also support the alteration in roughness values.
Frequency-resolved photon correlations in cavity optomechanics
Authors: Schmidt M K , Esteban R , Giedke G , Aizpurua J , González-Tudela A 
Published: February 2021

Abstract
Frequency-resolved photon correlations have proven to be a useful resource to unveil nonlinearities hidden in standard observables such as the spectrum or the standard (color-blind) photon correlations. In this manuscript, we analyze the frequency-resolved correlations of the photons being emitted from an optomechanical system where light is nonlinearly coupled to the quantized motion of a mechanical mode of a resonator, but where the quantum nonlinear response is typically hard to evidence. We present and unravel a rich landscape of frequency-resolved correlations, and discuss how the time-delayed correlations can reveal information about the dynamics of the system. We also study the dependence of correlations on relevant parameters such as the single-photon coupling strength, the filtering linewidth, or the thermal noise in the environment. This enriched understanding of the system can trigger new experiments to probe nonlinear phenomena in optomechanics, and provide insights into dynamics of generic nonlinear systems.
Reinforcement learning in discrete action space applied to inverse defect design
Authors: Loeffler Troy D , Banik Suvo , Patra Tarak K , Sternberg Michael , Sankaranarayanan Subramanian K R S 
Published: February 2021

Abstract
Reinforcement learning (RL) algorithms that include Monte Carlo Tree Search (MCTS) have found tremendous success in computer games such as Go, Shiga and Chess. Such learning algorithms have demonstrated super-human capabilities in navigating through an exhaustive discrete action search space. Motivated by their success in computer games, we demonstrate that RL can be applied to inverse materials design problems. We deploy RL for a representative case of the optimal atomic scale inverse design of extended defects via rearrangement of chalcogen (e.g. S) vacancies in 2D transition metal dichalcogenides (e.g. MoS2). These defect rearrangements and their dynamics are important from the perspective of tunable phase transition in 2D materials i.e. 2H (semi-conducting) to 1T (metallic) in MoS2. We demonstrate the ability of MCTS interfaced with a reactive molecular dynamics simulator to efficiently sample the defect phase space and perform inverse design—starting from randomly distributed S vacancies, the optimal defect rearrangement of defects corresponds a line defect of S vacancies. We compare MCTS performance with evolutionary optimization i.e. genetic algorithms and show that MCTS converges to a better optimal solution (lower objective) and in fewer evaluations compared to GA. We also comprehensively evaluate and discuss the effect of MCTS hyperparameters on the convergence to solution. Overall, our study demonstrates the effectives of using RL approaches that operate in discrete action space for inverse defect design problems.
Optimal flapping wing shape and kinematics are different for different flight velocities: an analysis on local relative wind
Authors: Kumaresan Allwyn , Ganapathy Subramanian L R 
Published: February 2021

Abstract
Different species of insects and birds fly differently. Their wing forms and wing motion are different. Understanding the purpose of this difference will lead to successful development of flapping wing vehicles for different purposes. This paper discusses the influence of one of the important factors which affects the aerodynamic performance of a flapping wing: the local instantaneous relative wind. Its distribution along the span of a flapping wing has been analyzed for the practical flight range of advance ratios ranging from 0 to 1.5 and stroke plane orientations ranging from 0 to 90°. In this domain, the variation of spanwise distributions of magnitude and direction of relative wind are presented separately for downstroke and upstroke of a flapping cycle. Accordingly, qualitative suggestions are given for wing planform design, orientation and twist of the wing, and actuation of wing for effective utilization of the relative wind and obtaining the necessary force distributions for different flight phases. The formulation presented will be helpful for experimenting flapping wings in hovering and forward flight; especially for setting the wing twist for a required angle of attack distribution and designing the flapping kinematics in upstroke and downstroke.
Contrarian effects and echo chamber formation in opinion dynamics
Authors: Ferraz de Arruda Henrique , Benatti Alexandre , Nascimento Silva Filipi , Comin César Henrique , da Fontoura Costa Luciano 
Published: February 2021

AbstractThe relationship between the topology of a network and specific types of dynamics unfolding in networks constitutes a subject of substantial interest. One type of dynamics that has attracted increasing attention because of its several potential implications is opinion formation. A phenomenon of particular importance, known to take place in opinion formation, is echo chambers’ appearance. In the present work, we approach this phenomenon, while emphasizing the influence of contrarian opinions in a multi-opinion scenario. To define the contrarian opinion, we considered theunderdogeffect, which is the eventual tendency of people to support the less popular option. We also considered an adaptation of the Sznajd dynamics with the possibility of friendship rewiring, performed on several network models. We analyze the relationship between topology and opinion dynamics by considering two measurements: opinion diversity and network modularity. Two specific situations have been addressed: (i) the agents can reconnect only with others sharing the same opinion; and (ii) same as in the previous case, but with the agents reconnecting only within a limited neighborhood. This choice can be justified because, in general, friendship is a transitive property along with subsequent neighborhoods (e.g., two friends of a person tend to know each other). As the main results, we found that the underdog effect, if strong enough, can balance the agents’ opinions. On the other hand, this effect decreases the possibilities of echo chamber formation. We also found that the restricted reconnection case reduced the chances of echo chamber formation and led to smaller echo chambers.