bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinematics of the motorcar body side deformation process during front-to-side vehicle collision and the emergence of a hazard to car occupants
Authors: Prochowski Leon , Gidlewski Mirosław , Ziubiński Mateusz , Dziewiecki Krzysztof 
Published: January 2021

AbstractThe kinematics of the process of deformation of the motorcar body side in the culminating phase of a front-to-side vehicle collision has been examined as a possible basis for analyzing and modeling the process of emergence of a hazard to car occupants during a road accident. The course of such accidents has a complex nature and their models are necessarily based on the approximation of non-linear elastoplastic characteristics of impact processes, especially during the transition from the compression phase to the restitution phase of the deformation process. For such characteristics to be obtained, a lot of experimental tests have to be carried out. This paper addresses the short-duration processes with a high degree of complexity.A front-to-side motorcar collision model has been prepared, which made it possible to analyze the process of deformation of the car body side and the emergence of a hazard and injuries to car occupants. The results of calculation of the deformation rate and range in various car body zones, velocity of the test dummy placed on driver’s seat and velocity of possible dummy’s impact against the car body side being deformed may be taken as a basis for designing effective occupant protection systems. The kinematics of the phase of vehicle contact and deformation process was modeled with taking into account results of experimental tests, including the curves characterizing the largely non-linear processes that are decisive for the deformation of the car body side. The deformation processes analyzed on these grounds showed at the same time the range of penetration of the deformed body part into the car interior, which causes a hazard to vehicle occupants. The calculation results have shown e.g. that the car body side is deformed to a depth of 0.2 m as quickly as within 0.02–0.03 s. At such a car body side deformation range, the car body part being deformed hits occupant’s body in his/her hips and pelvis area with a velocity of about 6 m/s.
A Mineralogical Investigation on Volatilization of Impurity Elements from Cu-Rich Polymetallic Concentrates During Roasting in Inert Atmosphere
Authors: Prasad Pande Nishant , McElroy Iris , Lennartsson Andreas , Samuelsson Caisa 
Published: January 2021

Abstract
Four different Cu-rich polymetallic concentrates are tested for volatilization of Sb and As during laboratory-scale roasting. The experiments are performed between 200 °C and 700 °C, at intervals of 100 °C and in an inert atmosphere. Sb volatilization is much less (maximum approximately 45 pct) than As volatilization (maximum approximately 95 pct) in these conditions at 700 °C. As volatilization is however limited from the concentrate having As mainly in a tetrahedrite solid solution ((Cu,Ag,Fe,Zn)12(Sb,As)4S13). Sb and As retained in the roasted calcine are found in the low-melting liquid phase, formed at approximately 500 °C. This melt phase gets enlarged and enriched in Sb with an increase in temperature. However, there is noticeable As volatilization from this melt phase with the temperature approaching 700 °C. Furthermore, there is an early and relatively high Sb volatilization from the concentrate having Sb substantially as gudmundite. Micron-scale elemental redistribution in gudmundite in the 350 °C roasted calcine confirms its transformation at this temperature. Other Sb minerals did not undergo any detectable transformation at this temperature, suggesting that the significant Sb volatilization starting between 300 °C and 400 °C was primarily from gudmundite. This benign attribute of gudmundite featured in this work in the context of roasting should also be relevant from the geometallurgical perspective during concentrate production, where concentrates bearing Sb are considered substandard for further Cu extraction irrespective of the Sb mineralogy.
Numerical investigation of the effects of fuselage upsweep in a propulsive fuselage concept
Authors: Habermann Anaïs Luisa , Gokhale Anubhav , Hornung Mirko 
Published: January 2021

AbstractIn recent years, aircraft concepts employing wake-filling devices to reduce mission fuel burn have gained increasing attention. The study presented here aims at a detailed physical understanding of the effects of integrating a propulsive fuselage device on a commercial aircraft. Compared to an isolated, axisymmetric fuselage-propulsor configuration, a propulsive fuselage device experiences an increased circumferential inlet distortion due to three-dimensional geometric features of the aircraft. This study uses three-dimensional CFD simulations to investigate the effect of fuselage upsweep on the aero-propulsive performance of an aircraft configuration featuring a boundary layer ingestion device. It is shown that fuselage upsweep has a negative impact on the performance of a propulsive fuselage device as compared to an axisymmetric configuration. Increasing the upsweep angle by $$\Delta \alpha _{{{\text{SW}},{\text{PFC}}}} = 3.5^\circ$$

Δ

α

SW
,
PFC

=
3
.

5
∘

leads to an increase in required fuselage fan shaft power by 19%. Furthermore, it is demonstrated that the negative effects of fuselage upsweep on the propulsor’s performance can be effectively mitigated by a circumferential variation in the propulsor nacelle thickness.
PSA-tests bij mannen ouder dan 74 jaar: zwart-wit of toch een grijs gebied?
Authors: Remmers Sebastiaan , Hogenhout Renée , Roobol Monique J. ,   ERSPC Rotterdam Study Group
Published: January 2021

SamenvattingProstaatkankerscreening middels PSA bij mannen > 70–74 jaar wordt afgeraden vanwege overdiagnostiek. In deze studie proberen we te achterhalen of er een subgroep te identificeren is – levensverwachting en kwaliteit van leven in ogenschouw genomen – waarbij screening nog wel zinvol zou kunnen zijn. Geïncludeerd werden mannen van 70–74 jaar die waren ingeloot in de interventiearm van de ERSPC Rotterdam en niet waren gediagnosticeerd met prostaatcarcinoom ten tijde van de screening. In dit artikel worden de incidentie en de mortaliteitsdata beschreven. Uiteindelijk werden 3.040 mannen geïncludeerd. Gedurende een periode van 24 jaar ontwikkelden 202 mannen prostaatkanker (7 %), van wie er 52 (26 %) metastasen kregen en 26 % overleed aan de ziekte. De PSA-waarde ten tijde van screening was voorspellend voor prostaatkankersterfte. De conclusie luidde dat mannen > 74 jaar niet per definitie moeten worden uitgesloten van prostaatkankerscreening, gezien de kans op metastasen en sterftecijfers. Beoordeling van vitaliteit en counseling over nadelen van screening vormen, samen met PSA-bepaling en verdere risicostratificatie, de sleutel tot zinvolle screening.
Coming of Age: Devising Legislation for Adolescent Medical Decision-Making
Authors: Hartman Rhonda Gay 
Published: January 2021

A substantial segment of the American population consists of adolescents. Adolescents, defined as persons between the ages of fourteen and eighteen, have traditionally been regarded as “minors” by law. Minors, as a group, are legally disabled, meaning they are presumed to lack the skills necessary for capable decision-making. Capable decision-making is requisite to the exercise of legal rights. Although the U.S. Supreme Court has extended federal constitutional guarantees to minors, including the liberty right for decision-making in intimate, personal matters, the Supreme Court has observed that vulnerability impairs their decision-making capability. Accordingly, the law regulates decision-making liberties of minors far more extensively than those of adults.The underlying tenet of law governing adolescents—that they lack the skills required for capable decision-making—seems well-settled. It is an artifact from an industrial society that spawned legislation authorizing governmental regulation of adolescents for education and labor in order to protect and promote their health and well-being.
Uncovering the Rationale for Requiring Infertility in Surrogacy Arrangements
Authors: Wilson Robin Fretwell 
Published: January 2021

Anyone who reads numerous statutes is frequently left scratching his or her head: is this provision a deliberate, rational requirement or filler thrown in for no apparent reason? One puzzling requirement peppering state surrogacy statutes is the limitation of surrogate parenting arrangements to couples in which the intended mother is infertile, unable to bear a child or unable to carry the child without unreasonable risk to the mother or child. The legislative history of these statutes offers no explanation for this emphasis on maternal infertility.The only attempted justification for such a requirement comes from commentators who argue that it bars women who want to avoid the nuisance of being pregnant and giving birth from using a surrogate.
Active feedforward control of flexural waves in an Acoustic Black Hole terminated beam
Authors: Cheer J , Hook K , Daley S 
Published: January 2021

Abstract
Acoustic Black Holes (ABHs) are structural features that are typically realised by introducing a tapering thickness profile into a structure that results in local regions of wave-speed reduction and a corresponding enhancement in the structural damping. In the ideal theoretical case, where the ABH tapers to zero thickness, the wave-speed reaches zero and the wave entering the ABH can be perfectly absorbed. In practical realisations, however, the thickness of the ABH taper and thus the wave-speed remain finite. In this case, to obtain high levels of structural damping, the ABH is typically combined with a passive damping material, such as a viscoelastic layer. This paper investigates the potential performance enhancements that can be achieved by replacing the complementary passive damping material with an active vibration control (AVC) system in a beam-based ABH, thus creating an active ABH (AABH). The proposed smart structure thus consists of a piezo-electric patch actuator, which is integrated into the ABH taper in place of the passive damping, and a wave-based, feedforward AVC strategy, which aims to minimise the broadband flexural wave reflection coefficient. To evaluate the relative performance of the proposed AABH, an identical AVC strategy is also applied to a beam with a constant thickness termination. It is demonstrated through experimental implementation, that the AABH is able to achieve equivalent broadband performance to the constant thickness beam-based AVC system, but with a lower computational requirement and a lower control effort, thus offering significant practical benefits.
Numerical modeling of non-stationary heat problems in a two-phase medium
Authors: Gladkikh V S , Ilin V P , Petukhov A V , Krylov A M 
Published: January 2021

Abstract
The simulation of thermal fields and melting permafrost is an important step for engineering construction in many regions of Russia. Water-ice phase transitions in a 3D complicated computation domain must be taken into account. The enthalpy statement with an implicit finite volume method was used to create a good discretization and a local mesh refinement to focus an area near the oil well. System of linear algebraic equations is solved using the iterative conjugate residual or conjugate gradient method in Krylov subspaces with the incomplete factorization algorithm in the Eisenstat modification as a preconditioner. A special high-parallel version of matrix generation and solving a system of the linear algebraic equations code have been developed and then efficiency has been estimated. The performance results of the developed code and temperature fields for different wells configuration (1 well and 4 wells placed as squared) during 5 years have been presented. The results validation was based on the comparison with previous papers and other algorithms. The results of simulations are close those to presented by other authors.
Nested Alternating - Triangular Incomplete Factorization Methods
Authors: Gololobov S V , Il’in V P , Krylov A M , Petukhov A V 
Published: January 2021

Abstract
We consider several versions of incomplete nested factorization methods for solving the large systems of linear algebraic equations (SLAEs) with sparse matrices which arise in grid approximations of the multi-dimensional boundary value problems. Our approach is based on the two-level iterative process in the Krylov subspaces in 3D case. Corresponding hierarchical incomplete factorization is applied to the block tridiagonal matrix structure. At the upper level, the diagonal blocks correspond to 2D grid subproblems which are factorized in the line-by-line framework. Instead of the low and upper triangular matrix factors, the alternating triangular matrices are used, which allows to apply the parallel counter sweeping approaches. The improvement of preconditioners is made by means of generalized compensation principles. To solve SLAE iterative conjugate direction methods in Krylov subspaces are applied. The efficiency of the proposed methods are demonstrated on the set of representative test problems.
Preconditioning methods based on spanning tree algorithms
Authors: Perevozkin D V , Omarova G A 
Published: January 2021

Abstract
The work continues the research performed by Chen and Toledo as a follow-up to Vaidya’s talk. The preconditioners being discussed are based on spanning tree algorithms where the input is the graph arising from the matrix of the system of linear algebraic equations (SLAE). The methods are considered in application to solving various SLAEs with real symmetric and non-symmetric matrices. The research shows that the application area of the preconditioners in question may significantly differ from the domain indicated in the literature.
Sign language recognition through Leap Motion controller and input prediction algorithm
Authors: Enikeev D G , Mustafina S A 
Published: January 2021

Abstract
The sign recognition systems are aimed to help deaf people communicate with society. In this paper we proposed our own concept of sign language recognition, which is based on a co-operative deep learning neural network, a text input prediction algorithm and a feedback from the user. We have pointed out the complexity of the Russian sign language and conceived the fingerspelling recognition. The method utilizes the natural properties of fingerspelling in order to increase the accuracy and recognition performance by predicting the ongoing letter. We also provide a detailed review of data acquisition in the related works. From a hardware perspective, we suggest using Leap Motion controller.
The PCA-seq method applied to analyze of the dynamics of COVID-19 epidemic indicators
Authors: Efimov V M , Polunin D A , Kovaleva V Y , Efimov K V 
Published: January 2021

Abstract
In time series analysis using the SSA method, a univariate series is converted into the multivariate one by shifts. The resulting trajectory matrix is subjected to principal component analysis (PCA). However, the principal components can also be computed using the PCA-Seq method if segments of the original series are selected as objects. The matrix of Euclidean distances between the objects can be obtained using any method, which offers additional opportunities for time series analysis compared to the conventional SSA. In this study, the PCA-Seq method was used to analyze the dynamics of COVID-19 epidemic indicators.
The least-squares collocation method in the mechanics of deformable solids
Authors: Golushko Sergey , Shapeev Vasily , Belyaev Vasily , Bryndin Luka , Boltaev Artem , Gorynin Arseniy 
Published: January 2021

AbstractThe paper is devoted to the application of the least-squares collocation method for solving the two- and one-dimensional problems in the mechanics of deformable solids. Calculation results of the deflections of isotropic and orthotropic elastic plates within the framework of various theories are presented. This paper shows that approximate solutions obtained by the hp-version of the least-squares collocation method converge with a high order and agree with analytical solutions of test problems with a high degree of accuracy. Numerical and mathematical modeling of three-point bending of composite beams was carried out taking into account nonlinear stress-strain relationships, multi-modulus behavior, and incipient fracture. It was found that the simulation results are in good agreement with the results of mechanical tests of three-point bending of composite beams.
On a singular value decomposition of the normal Radon transform operator acting on 3D 2-tensor fields
Authors: Polyakova A P , Svetov I E 
Published: January 2021

AbstractWe consider the problem of reconstructing the potential part of a symmetric 2-tensor field defined in a unit ball by its known values of the normal Radon transform. To solve the problem, a singular value decomposition of the normal Radon transform operator is constructed. The basis functions and fields using the Jacobi, Gegenbauer polynomials and spherical harmonics are constructed.
On nonconvex optimal control problems
Authors: Strekalovsky A S 
Published: January 2021

Abstract
The paper addresses the general optimal control (OC) problem with inequality constraints and a cost functional of Bolza given by d.c. functions with respect to the state in the terminal and integrand parts of the functionals. First, we reduce the original OC problem with inequality constraints to the one without constraints with the help of the Exact Penalization Theory. Further, we show that the auxiliary (penalized) problem also possesses the state-DC-structure. Employing this property, we develop the new Global Optimality Conditions (GOCs) and discuss some its features allowing to construct the new schemes of local and global searchers. Finally we elucidate the relations of the GOCs to the classical OC theory, in particular, to the Pontryagin’s maximum principle.
Coordinate basis adaptation of cataloging of unified immovable complexes included into the Russian-Chinese initiative project “One Belt – One Way” (by example railway transport)
Authors: Portnov A M 
Published: January 2021

AbstractCoordinate support is a fundamental basis to study the characteristics of objects and phenomena which occur in the surrounding space. Parameterization of the characteristics is impossible if the rules for describing objects either within themselves or concerning their topological properties are not established. The rules for the metric description of the terrain objects at the level of general state geodetic and cartographic support tasks are determined. Nevertheless, there are quite important tasks to describe some elements of the sets for which the established rules are not considered as optimal, so it will be a more efficient solution to switch to alternative parameters of metric systems. Such objects include linear objects (such as real estate, buildings, natural objects) on the Earth’s surface which are characterized by a significant accumulation of errors in their description in the established coordinate systems (projections). If considered applied, there is some certain necessity to determine (calculate) the optimal rules (parameters) in a number of cases in order to form the metric system of their description for the design and departmental cataloging.
Preferential attachment in the citation network of scientific articles
Authors: Scherbakova N G , Bredikhin S V 
Published: January 2021

Abstract
We study the citation network of scientific articles in the hypothesis that the likelihood of connecting to a node depends on the node’s degree, a mechanism called the preferential attachment. We show that the rate at which articles acquire citations linearly depends on the number of citations already received and we find the functional form of the dependence basing on the analysis of the dynamic source data. We also investigate the effect of the article age on receiving citations and show that there is the exponential decay of interest to old articles. Nevertheless the distribution of citations has the power-law form.
Statistical filtering algorithms based on the maximum cross section method for stochastic systems with regime switching
Authors: Averina T , Rybakov K 
Published: January 2021

Abstract
New statistical algorithms are formed to estimate the state vector of stochastic systems with regime switching. These algorithms are based on the particle method, i.e., on numerical methods for solving stochastic differential equations, methods for modeling conditional Markov processes with a finite set of states, and methods for calculating weights. An important part of proposed algorithms is the use of the maximum cross section method and its modification, which allows the exact simulation of the regime switching process. This paper continues the authors’ research in the field of statistical methods and algorithms of the analysis and filtering for continuous-time stochastic systems.
A discontinuous particle method for the inviscid Burgers’ equation
Authors: Bogomolov S V , Filippova M A , Kuvshinnikov A E 
Published: January 2021

Abstract
The discontinuous particle method for simple problems associated with gas dynamics is under consideration. The origin of the method is based on the micro-model describing the movement of particles with prescribed velocities. We show that with the micro-model the inviscid Burgers’ equation is solved in a weak sense. Numerical experiments have confirmed a low viscosity of the method: the solution is smeared by only one particle.
Method for optimizing the shell of open pit mines based on parallel computing
Authors: Petrov D V , Mikhelev V M , Petrova E V 
Published: January 2021

Abstract
One of the main stages in design of mineral development process is solution of finding optimal open pit problem. It is necessary to take into account the spatial distribution of mineral components and the allowable slope angles of the sides during solving this problem. The basis for performing calculations to optimize the extraction of reserves is a digital block model of the mineral deposit. The larger and more accurate block model of the ore deposit requires more computationally complex calculation process. In this regard, using of parallel computing in this area is very relevant. The importance of solving this problem determined by the need to have an accurate model of the open pit at various stages of its development. This model depends from current cost of useful components and the costs of their extraction. This task formulated as the Ultimate Pit Problem (UPIT). Existing approaches for solving this problem does not use modern high-performance computing approaches. This complicates analysis of large models using existing methods. The long data processing time makes it difficult to increase the accuracy of the constructed quarry models, which in turn negatively affects decision-making on the field development plan and entails lost profit. In this paper analysed the methods of computer modelling open pits from the position of parallelizing computations during profit optimization and proposes a mathematical formulation of the problem of searching for open pit limits based on block extraction order graph.