bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calculating Global Minimum Points to Binary Polynomial Optimization Problem: Optimizing the Optimal PMU Localization Problem as a Case-Study
Authors: Theodorakatos Nikolaos P. , Moschoudis Angelos P. , Babu Rohit 
Published: February 2024

Abstract
State estimation (SE) is an algorithmic function of an energy management system (EMS). SE provides an actual-time monitoring and control of modern electrical power grids. State Estimation can be worked with sufficiency using Phasor Measurement Units optimally placed within a power grid. This paper concerns the implementation of proper algorithms embedded in optimization solvers to the optimal PMU localization problem solving globally. The optimization model is formulated as a 0 - 1 nonlinear minimization problem. The problem is transformed to a polyhedron using linearization methods and B&B tree. In this model, we use a linear cost function under polynomial constraints and binary restrictions on the design variables in a symbolic format. This mathematical model is programmed in the YALMIP environment which is fully compatible with MATLAB. The 0 - 1 Nonlinear Programming (NLP) model is suitable for getting concisely global optimal solutions. The optimal solution is given by a wrapped optimization engine including a local optimizer routine performing together with a mixed-Integer-Linear Programming routine. The solution is achieved within a zero-gap precisely encountered during the iterative process. This tolerance criterion is a necessity for a successful implementation of the B&B tree because it ensures global optimality with an acceptance relative gap. The minimization model is implemented in a YALMIP code fully compatible with MATLAB in two stages. Initially, an objective function with one term is minimized to discover a number of sensors for wide-area monitoring, control and state estimator applications. Then, an extra product is considered in the objective to suffice maximum reliability for observing the network buses. The numerical minimization models are applied to standard power networks in the direction to be solved globally.
An Incomplete Observability-Constrained PMU Allocation Problem by Using Mathematical and Evolutionary Algorithms
Authors: Theodorakatos Nikolaos P. , Babu Rohit , Moschoudis Angelos P. 
Published: February 2024

Abstract
The purpose of this paper is to introduce several optimization algorithms that can be used to address optimization models in the power network, where the level of observability may be either complete or incomplete. These algorithms include discrete, continuous and metaheuristic methods. Initially, the optimization problem is approached by implementing a zero-one mixed integer linear program solved by several methods, including branch and bound revised simplex and primal dual-simplex in combination with interior point algorithms. To solve the problem of depth-one-unobservability (DoOU), a nonlinear program is proposed using Sequential Quadratic Programming (SQP), Interior-Point methods (IPMs) or YALMIP\s branch-and-bound algorithm. Additionally, the paper proposes the use of metaheuristic algorithms, such as Genetic Algorithms (GAs) and Binary Particle Swarm Optimization (BPSO), to solve optimization problems under incomplete observability. The proposed algorithms are tested using simulations on IEEE standard systems to illustrate their efficiency and reliability in solving the optimization problem under partial observability. Overall, the paper concludes that these algorithms can efficiently lead to the optimum point in a reasonable runtime. Hence, this work examines the problem of putting a restricted PMUs number to make the DoOU and to give a feedback to the state estimation routine accuracy.
Geogebra in the visualization of integrating factors in non-exact differential equations
Authors: Olivares Jorge , Martin P. , Valero E. 
Published: February 2024

Abstract
In the present work, integrating factors used in the solution of non-exact differential equations will be shown with general examples through software application of dynamic geometry GeoGebra. Now these applets are part of theteaching support material in the eigineering careers of the University of Antofagasta on 2020.
Subdiffusive dynamics and hydrodynamic fluctuations: how the latter affect the former.
Authors: Bakalis Evangelos , Zerbetto Francesco 
Published: February 2024

Abstract
The characteristics of subdiffusion are influenced by hydrodynamic fluctuations, not the scaling of the mean square displacement (MSD) at the long time limit, but rather the transition of this property from ballistic behaviour at early times to its final scaling at large times. Additionally, since a significant portion of the normalised velocity autocorrelation function (NVAF), a widely used motion descriptor, no longer adequately describes the antipersistent character that is typical of a subdiffusive motion, it is also impacted by these fluctuations. The combined findings can lead to misleading conclusions if hydrodynamic fluctuations are not taken into account. Diffusing and vorticity time scales are crucial for the way the motion turns into the final subdiffusion dynamics, whose exponent is determined by the scaling of the friction.
Statistical moments for simulation calibration with model-bridge
Authors: Batalo B , Souza LS , Yamazaki K 
Published: February 2024

Abstract
Computer simulations are actively used for analyzing complex phenomena, especially in fields where access to their real-world counterparts is not feasible, such as physics, chemistry, material science, and others. The key to executing successful simulations is making sure that the parameters of a simulator reflect real-world scenarios, a tedious and error-prone effort addressed through simulation calibration. Recently, several methods have been proposed to automatize this task by learning from previously calibrated simulations using a model-bridge paradigm: a complex simulation is replaced by a simpler surrogate model, which can then be bridged to the calibrated simulation parameters. However, designing the surrogate model is a non-trivial problem involving trade-offs between simplicity of representation, interpretability and calibration accuracy, as well as the complexity of the bridge model required to map the surrogate to calibrated parameters. Further, while effective, such approaches can be non-intuitive for practitioners due to their distance from the simulation. In this paper, we view a simulation as a distribution of output variables, which can be easily represented by statistical moments. This yields a very simple and interpretable surrogate that can be bridged to calibrated parameters with a simple linear regression. We show that our method outperforms previous approaches, in terms of calibration accuracy and time, through experiments on simulations of turbulent flow dynamics and synthetic signals.
LES analysis of local isotropic turbulence depending on the spatial scale of the external forcing field
Authors: Minami Koki , Suzuki Hiroki , Kouchi Toshinori 
Published: February 2024

Abstract
The study investigates the effect of the parameterisation of an external force scheme based on trigonometric functions on turbulence. In particular, the dependence of the generated turbulence on the Reynolds number and the influence of its spatial parameters are investigated. The turbulence used is generated by a large-eddy simulation based on a high-precision finite volume method, and the turbulence energy and isotropy of the turbulence are also investigated. The parameter of the external force field used in this study characterises the wavelength of the trigonometric function, and the influence of this parameter on the spatial scale is studied in detail. As a result, steady turbulent fields are generated and isotropic turbulence is observed at different spatial scales of the external force field with M=2, 3 and 4. The property of increasing turbulence energy with increasing Reynolds number is confirmed.
Computer Simulation of Explosive Emission Processes in Strong Electromagnetic Fields
Authors: Galstyan E.A. , Kudryashova T.A. , Polyakov S.V. , Tarasov N.I. 
Published: February 2024

Abstract
The paper discusses the problem of computer simulation of explosive emission processes in strong electromagnetic fields. In this work, a numerical method for calculating electron emission from the surface of a metal cathode for the axial symmetric geometry of a technical system is proposed. For modelling, the particle method and grid calculations of electromagnetic fields based on Maxwell’s equations are applied. The approach uses the representation of large smoothed Gaussian particles and implements calculations of the electromagnetic fields on Cartesian spatial grids. The software realization is directed towards on parallel computing. The calculation of the emission process in a coaxial cylindrical diode with magnetic self-insulation with the use of developed technique was carried out. The process is considered for two situations: with and without the longitudinal plasma layer. The calculations show that the presence of plasma leads to an increase in the emission current. This result is consistent with the results of experiments.
Modeling of the Influence of Oxidation on the Energy of Interfacial Exchange Interaction in Co/CoO Films
Authors: Brykin L. O. , Afremov L. L. 
Published: February 2024

Abstract
The interphase exchange interaction energy of ferromagnetic/antiferromagnetic films is determined through the mean spin theory. The thickness of the oxidized layer affects the exchange field, as shown by the Co/CoO film.
Linear stability of viscoplastic flows down an incline
Authors: Calusi Benedetta , Farina Angiolo , Fusi Lorenzo , Iulian Palade Liviu , Rosso Fabio 
Published: February 2024

Abstract
The stability analysis of viscoplastic flows down an inclined plane is done by comparing results obtained through theoretical and numerical studies of “regularized” models. The theoretical analysis is performed for Regularized Bingham and Casson-like fluids via the long-wave approximation method. In particular, the Bingham and the Casson flow have different stability characteristics, for Bingham-type materials an increase in yield stress leads to flow destabilization, while Casson-type materials show the opposite behaviour. The numerical study is performed by using the Papanastasiou and the “exact” Bingham model via a spectral method. The comparison between theoretical and numerical results shows excellent agreement. Our findings highlight that “regularized” and “exact” flow and can have stability characteristics, although they are “practically indistinguishable”. We validate our approach with the Regularized Bingham-like model, which is in rather satisfactory agreement with the experimental data.
Theoretical modeling of the electronic structure and Fermi surfaces of Gd4Sb3 and GdSb2 compounds
Authors: Baidak S T , Lukoyanov A V 
Published: February 2024

Abstract
Our theoretical modeling of the electronic structure in the intermetallic Gd4Sb3 and GdSb2 compounds has been done in the framework of density functional theory accounting for spin-orbit coupling. It revealed the metallic character of the summed total density of electronic states for both materials. The complicated Fermi surfaces were found in the half-metallic Gd4Sb3 compound which corresponds to the band structure. The GdSb2 material is obtained to be a bad metal with the low density of states near the Fermi energy, the Fermi surfaces of GdSb2 are found to have the cylindrical shape.
How Fast Do Distribution and Semantics of Polysemic Words Change?
Authors: Bochkarev Vladimir V. , Shevlyakova Anna V. 
Published: February 2024

Abstract
Creation of large diachronic text corpora triggered studies of evolution of natural languages using quantitative methods in the last decade. For the first time, it became possible to raise questions about general patterns of lexical semantic change. In the work by W. Hamilton et al., 2016, a hypothesis was formulated about a more rapid change in the meanings of polysemic words. In this paper, we consider how frequency of words influence variations of semantic metrics. We use explicit word vector representations and Jensen-Shannon divergence as a measure of change in the distribution and semantics of a word. The obtained results show that changes in the frequency ratio of a word in different meanings can themselves lead to a change in a word distribution, even in the absence of any changes in its meaning. Therefore, the observations made in the work by W. Hamilton et al about correlation between the rate of change of words and their local cluster coefficient in the semantic connection network (considered as a quantitative measure of polysemy) can be fully explained by the effect described in the article.
Passive damping of vibrations of prestressed thin-walled structures using piezoelectric elements connected to electric circuits
Authors: Lekomtsev Sergey V , Matveenko Valerii P , Senin Alexander N 
Published: February 2024

Abstract
In this paper we estimate the influence of static pressure on the efficiency of passive damping of vibrations of a circular cylindrical shell using an open piezoelectric ring connected to a passive electric circuit of different configurations. The mathematical formulation of the problem of the dynamic behavior of an electroelastic structure is based on the variational principle of virtual displacements, which is written in matrix form taking into account the prestressed non-deformed state caused by applied loads, and as well as the work done by external surface forces, inertial forces and external electric field to transfer the free charge. The resulting equation is supplemented by the equation for the electric circuit, which relates the voltage at the piezoelectric ring with the corresponding electric charge. The problem is solved in the framework of 3D formulation using the finite element method. As examples, we consider the serial RL- and resistive R-circuits. Their parameters providing the most effective damping of free vibrations in terms of their decay rate are determined by solving the optimization problem. The results obtained by numerical simulations are compared with the results calculated by the analytical formulas at different values of static pressure.
Predictive analysis in industry
Authors: Echkina Eugenia , Levichev Alexander , Sushko Andrey 
Published: February 2024

Abstract
Predictive analytics is a field of knowledge that allows you to make informed decisions, prepare for unforeseen situations and anticipate all kinds of emergencies. Recently, predictive analysis has been actively used in industry: based on historical data, the model makes a probabilistic forecast of the device’s behavior in the near future. This paper provides a comparative analysis of two predictive models, which both could self-learn and had the property of self-correction. The accuracy of predicting the development of a defect in industrial equipment, as well as the prediction horizon, were evaluated. Particular attention is paid to the peculiarity of working with data obtained from production sensors.
Application of higher-order FV-WENO scheme to the interaction between shock wave and bubble
Authors: Yu J , Hao Y , Sheng Z X , Zhang X P , Chen J P , Zhang J , Yang J 
Published: February 2024

Abstract
The high-order finite volume-WENO (Weighted Essentially Non-Oscillatory) scheme combines the finite volume method with the WENO method, allowing for high-order accuracy and accurate simulation of complex physical phenomena. It has advantages in handling shock waves and bubble interactions. The idea of this method is to discretize the physical equations into a set of conservation equations and use the WENO method to calculate the numerical fluxes on each finite volume cell. This approach is effective in dealing with problems such as shock wave propagation, bubble deformation, and evolution. In fluid dynamics simulation and research, the high-order FV-WENO scheme has significant application prospects. It can provide accurate numerical solutions and simulate complex physical phenomena, making it widely applicable in scientific research and engineering. In this study, we simulated the interactions between shock waves and single or double bubbles, obtaining the complete process of bubble collapse with clear bubble interfaces and strong program stability.
Asymptotic behaviour for a parabolic p-Laplacian equation with an advection force
Authors: Aal-Rkhais Habeeb A. , Qasim Ruba H. 
Published: February 2024

Abstract
The rescaling method is presented to allow us establishing the interface functions and the nonnegative local solutions to the evolution of nonlinear degenerate parabolic p-Laplacian process with conservation laws that are posed in one-dimensional space. This equation has a self-similar solution which represents the main feature of this work. The Cauchy problem (CP) for this equation with specific restrictions in the range of parameters and the negative advection coefficient is considered. In this work, there are several regions to discuss the qualitative analysis for the local weak solutions and the asymptotic interfaces in the irregular domains. The dominating of the advection force over the p-Laplacian type diffusion will appear clearly in these regions. Moreover, the solutions of the CP for the degenerate parabolic p-Laplacian advection equations are asymptotically equal to the solutions of advection equations under some restrictions.
Invasive-Invaded Interaction Incorporating a Bramson Model with Density-Dependent Diffusion and a Non-Lipschitz Reaction
Authors: Luis Díaz Palencia José 
Published: February 2024

Abstract
The primary objective of the presented study is to investigate the pairwise interaction dynamics between invasive and invaded species, considering a model characterized by a non-regular, non-Lipschitz type reaction, as well as non-homogeneous diffusion. To achieve this, we begin with the foundational model proposed by Bramson in 1988 and tailor it to account for density-dependent diffusion and the non-Lipschitz type reaction, rendering it more applicable to our specific ecological scenario. Subsequently, our newly developed model is subjected to different analyses to ascertain the existence and uniqueness of positive weak solutions. It is noteworthy that density-dependent diffusive operators exhibit a property known as “finite propagation”, which manifests as the existence of a propagating front in the ecological system. Furthermore, we delve into the problem domain by employing the concept of traveling waves to identify specific solutions. A key outcome of our investigation is as follows: When both species propagate at significantly different speeds in the context of traveling waves, the interaction between them is deemed unstable, resulting in oscillations in the concentration of the invaded species. Conversely, when both species propagate within a similar range of speeds, the dynamics of the system are predominantly governed by the invasive species.
AMS Subject Classification: 35K55, 35K57, 35K59, 35K65
Identification of Variables Affecting Levels of Salt Concentrations in Shatt Al-Arab Water Using Modified Kernel Principal Component Analysis
Authors: Husham Mohammed Albasri Ahmed , Abdul Hameed Ashour Marwan 
Published: February 2024

Abstract
This study paper is an attempt to bring to light a new approach in the treatment of the Gaussian function. The Gaussian function is considered the basis for building the elements of the kernel matrix within the methodology of the kernel principal components that aims to reduce the dimensions and then determine the most influential variables. Besides, it works on reducing the mathematical complexity that can arise because of multidimensionality, especially if it is the data suffers from a non-linear problem in describing the relationships. This research paper has included processing the introductory parameter matrix (H) by adopting two types of matrices, namely (H
1 diagonal, and H
2 hybrid diagonal). For achieving the benefit of this paper, it has been applied to the phenomenon of salt concentrations in Shatt al-Arab water in Basra Governorate through a number of climatic variables for identification of the most influential variables. The modified Gaussian function (MGK) was used and compared with the traditional method (TGK) by adopting two methods of estimating the introductory parameter matrix H. The simulation results brought to light that the (MGK) could not achieve better results than the (TGK) for any type of matrices (H
1 & H
2), estimated by the two methods (NS-R, ROT). Despite this fact, the (MGK) and (TGK) were consistent in determining the climatic variables most affected by the rise in salt concentrations when adopting the (NS-R) method, which are (air temperature, minimum temperature, maximum temperature, and solar brightness). While when adopting the (ROT), the (MGK) determined other variables, while the traditional method identified the same variables mentioned above.
Unsupervised texture classification of 3D X-ray Micro-computed Tomography images
Authors: Almeghari Tamara A. I. , Soufiane Jouini Mohamed , Hjouj Fawaz 
Published: February 2024

Abstract
Characterizing rock proprieties is crucial in the oilfield to evaluate hydrocarbon reserves. Several studies showed a high correlation between rock properties and textures. Therefore, we propose integrating texture information in the images to identify precisely the most representative textures in highly heterogeneous rocks to estimate their properties. First, we implemented a steerable pyramid decomposition to extract the texture features. Then, those parameters were used as input for the Self-organizing map to classify the textures. Finally, by applying several models and comparing their results, we suggested the best approach to implement for texture classification.
Detailed Analysis of Energy Consumption for an Office Building
Authors: Bazenkov N , Petrov I 
Published: February 2024

Abstract
Modern buildings consume a significant share of global power production. The primary sources of the power consumption are heating, ventilation and air conditioning (HVAC), light, cooking equipment, technical equipment like elevators, office facilities. Optimization of the buildings power consumption requires real-life data both for strategic planing and operational control. Here we analyze detailed power consumption of a research institute campus which is a medium-sized office buildings. Our data contain detailed electric measurements of 100 three-phase power lines which power all facilities inside the building. Each line is associated with several power consumers like lights, HVAC and office equipment. We analyze weekly and monthly trends, typical patterns in power consumption, and provide rough analysis of what classes of power consumers are most active in specific periods of time.
40 MHz triggerless readout of the CMS Drift Tube muon detector
Authors: Migliorini M. , Pazzini J. , Triossi A. , Zanetti M. ,   the CMS Muon Group
Published: February 2024

AbstractThe Level-1 trigger scouting system of the CMS experiment aims at intercepting the intermediate data produced by the L1 trigger processors before the final trigger decision. This system can be complemented by adding the raw stream of data collected from the detector front-end, whenever the throughput is manageable. In this work, the triggerless readout of the CMS Drift Tubes (DT) detector is presented. This is realized by reading a sector of the DT which has been equipped with the preproduction of Phase-2 upgrade front-end boards. A Xilinx VCU118 acts as a concentrator of the Phase-2 demonstrator lpGBT links and transmits data to a server via 100G TCP/IP. First results coming from a test-stand mimicking the sector demonstrator are shown.