bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of a time-optimal control system for an extremal object
Authors: Pikina G.A. , Pashchenko F.F. , Pashchenko A.F.
Published: December 2021

The paper presents the derivation of the synthesis method for the algorithm of the time-optimal controller for a third order dynamic system. A model with an extreme second-order transient response with delay was adopted as an object of research. The constant speed actuator is represented by an integrator. The synthesis is based on using the Pontryagin’s maximum principle and describing the dynamics of a system in the state space using canonical variables. The verification of the correctness of the result obtained by the theorem of Feldbaum A.A. on the number of switchings of the direction of movement of the regulating body during the control interval has been executed. To calculate the canonical state variables, it is proposed to use the position of the regulator, the controlled value and the derivative calculated from its values, measured on real objects.
PGU-450 network heaters modes modelling with CCGT participation in regulating the electrical load in the heating mode
Authors: Arakelyan E K , Andryushin A V , Mezin S V , Yagupova Y Y
Published: December 2021

The features of a mathematical model for optimizing the distribution of heat and electricity at a large thermal power plant with a complex composition of equipment as part of traditional heating units and a heating CCGT are considered. The selection and justification of optimization criteria at different stages of preparation and entry of the station to the electricity and capacity market is given. The disadvantages of the previously proposed optimal distribution algorithms are analyzed in relation to thermal power plants with a complex composition of equipment and with a complex scheme for the supply of electricity and heat. A method and algorithm for solving the problem are proposed based on the equivalence of the CHP equipment and the decomposition of the problem taking into account the schemes of electricity and heat output. The description of mathematical optimization methods is given, taking into account the peculiarities of the CCGT operating modes at reduced loads. The requirements for information support when integrating the developed algorithm into the application software of the automated process control system based on the PTC are given.
Ensemble kalman filter and particle filter-based state estimation on electrical power systems
Authors: Cevallos Holger , Intriago Gabriel , Plaza Douglas
Published: December 2021

In this article, a referential study of the sequential importance sampling particle filter with a systematic resampling and the ensemble Kalman filter is provided to estimate the dynamic states of several synchronous machines connected to a modified 14-bus test case, when a balanced three-phase fault is applied at a bus bar near one of the generators. Both are supported by Monte Carlo simulations with practical noise and model uncertainty considerations. Such simulations were carried out in MATLAB by the Power System Toolbox, whereas the evaluation of the Particle Filter and the Ensemble Kalman Filter by script files developed inside the toolbox. The results obtained show that the particle filter has higher accuracy and more robustness to measurement and model noise than the ensemble Kalman filter, which helps support the feasibility of the method for dynamic state estimation applications.
Estimation of the trajectory of magnetic nanoparticles in non-newtonian vascular fluid with cancer through neuronal networks
Authors: Contreras Israel Esteban , Barragán Diego Alejandro , Camargo Luz Helena
Published: December 2021

Treatments to combat cancer seek to reach specific regions to ensure maximum efficiency and reduce the possible adverse effects that occur in the treatment. One of these strategies include the treatment with magnetic nanoparticles (NPM), which has presented promising results, however, aspects involved in the trajectory of the nanoparticles are not yet known. The aim of this work is estimating the behavior of NPM through supervised neural networks, for this, artificial neural networks were implemented, such as multilayer perceptron, with optimization algorithms in which the Levenberg Marquardt algorithm stands out, different trajectories of NPM were simulated, including parameters such as time, position in X and Y, the speed that the nanoparticles can reach and physical factors that interact in the distribution were considered, such as the gravitational field, the magnetic field, the Stokes force, the force of pushing and dragging with different values of viscosity in the blood, generating a database with optimized reaction times that allows a more accurate prediction. The architecture obtained with the artificial neural the network that contains the optimization algorithm [5 4 3 2], presented the best performance with a training MSE of 1.763E-07, a validation uRMSE of 0.0049, and trend probabilities of X 0.62 % and 0.576 % in Y.
Photosynthetic pigment-protein complexes optical response modeling optimized by Differential evolution: algorithm convergence study
Authors: Chesalin Denis D , Pishchalnikov Roman Y
Published: December 2021

Photosynthetic pigment-protein complexes are the essential parts of thylakoid membranes of higher plants and cyanobacteria. Besides many organic and inorganic molecules they contain pigments like chlorophyll, bacteriochlorophyll, and carotenoids, which absorb the incident light and transform it into the energy of the excited electronic states. The semiclassical theories such as molecular exciton theory and the multimode Brownian oscillator model allows us to simulate the linear and nonlinear optical response of any pigment-protein complex, however, the main disadvantage of those approaches is a significant amount of effective parameters needed to be found in order to reproduce the experimental data. To overcome these difficulties we used the Differential evolution method (DE) that belongs to the family of evolutionary optimization algorithms. Based on our preliminary studies of the linear optical properties of monomeric photosynthetic pigments using DE, we proceed to more complex systems like the reaction center of photosystem II isolated from higher plants (PSIIRC). PSIIRC contains only eight chlorophyll pigments, and therefore it is potentially a very promising subject to test DE as a powerful optimization procedure for simulation of the optical response of a system of interacting pigments. Using the theoretically simulated linear spectra of PSIIRC (absorption, circular dichroism, linear dichroism, and fluorescence), we investigated the dependence of the algorithm convergence on DE settings: strategies, crossover, weighting factor; eventually finding the optimal mode of operation of the optimization procedure.
Post-selected double teleportation and the modelling of its related non-local properties
Authors: Delgado Francisco , Cardoso-Isidoro Carlos
Published: December 2021

Quantum teleportation is a notable basement of quantum processing. It has been experimentally tested with outstanding growing success by introducing improvements and applied advances in the last two decades. Its quantum non-local properties have let to discover and introduce novel implementations based on it in quantum processing, cryptography, quantum resources generation among others. In the current work, we develop a scheme performing double teleportation on two different virtual receivers, while the sender is still able to post-select the final target of teleportation. This process can be then used to generate non-local resources in a coordinated way. Those resources can be transferred to one of the receivers in the form of the non-local resource desired. They are analysed in terms of their parametric behavior, and properties derived from the CHSH inequality.
A general method for rotational averages
Authors: Nessler Reed , Begzjav Tuguldur Kh.
Published: December 2021

The theory of nonlinear spectroscopy on randomly oriented molecules leads to the problem of averaging molecular quantities over random rotation. We solve this problem for arbitrary tensor rank by deriving a closed-form expression for the rotationally invariant tensor of averaged direction cosine products. From it, we obtain some useful new facts about this tensor. Our results serve to speed the inherently lengthy calculations of nonlinear optics.
Experimental Validation of the Mean Pitch Theory
Authors: Meda T , Rogala A
Published: December 2021

There are several types of exterior ballistic models used to calculate projectile’s flight trajectories. The most complex 6 degree of freedom rigid body model has many disadvantages to using it to create firing tables or rapid calculations in fire control systems. Some of ballistic phenomena can be simplified by empirical equations without significant loss of accuracy. This approach allowed to create standard NATO ballistic model for spin stabilized projectiles named Modified Point of Mass Model (PM Model). For fin (aerodynamically) stabilized projectiles like mortar projectiles simple Point of Mass Model is commonly used. The PM Model excludes many flight phenomena in calculations. In this paper authors show the mean pitch theory as an approximation of the natural fin stabilised projectile pitch during flight. The theory allows for simple improvement of accuracy of the trajectories calculation. In order to validate the theory data obtained from shooting of supersonic mortar projectiles were used. The comparison of accuracy between simple PM Model and PM Model including mean pitch theory were shown. Results were also compared with the angle of response theory.
Numerical simulation of changes in the electric properties of biological tissues under local heating by laser radiation
Authors: Kovalenko N V , Smirnov A V , Ryabushkin O A
Published: December 2021

The mathematical model that describes the local heating of biological tissues by optical radiation is introduced. Changes of the electric properties of biological tissues in such process can be used as a reliable tool for analyzing heating and damage degrees of tissues.
Collisions model between magnetic nanoparticles and the arterial wall
Authors: Garzón Daniela , Camargo Luz Helena , Rodríguez Diego Julián
Published: December 2021

At present, there are different treatments against cancer, however, some of them, such as chemotherapy, are very invasive for the human body, since they affect healthy tissues. Magnetic targeting of drugs by means of magnetic nanoparticles is one of the alternative techniques that has emerged in the last decade, it is based on the targeting of drug delivery to the tumor without affecting healthy tissues, via of injected nanoparticles with diamagnetic properties directly into the bloodstream, driven by external magnetic fields produced by permanent magnets. This technique in literature is often come upon as MTD for its acronym in English. In this work, a numerical model was developed in order to quantify the loss of nanoparticles in the process of interaction with the walls of the bloodstream. For this model, the Kinetic technique was used, quantifying the probability of adsorption and absorption taking into account the following parameters: diameter of the nanoparticle (200 nm), density of the nanoparticle (6450 kg · m
-3), diameter of the cell endothelial (0.1 μm - 1 μm), transcellular pores of the fenestrated endothelium (70 nm) and modulus of elasticity of the endothelium (4.1 ± 1.7 kPa).
Prediction of the microstructural grain evolution during selective laser melting by a cellular automata method
Authors: Wang Lin
Published: December 2021

The mechanical properties of additively fabricated metallic parts are closely correlated with their microstructural texture. Knowledge about the grain evolution phenomena during the additive manufacturing process is of essential importance to accurately control the final structural material properties. In this work, a two-dimensional model based on the cellular automata method was developed to predict the grain evolution in the selective laser melting process. The effectiveness of this presented model is proven by comparing the simulated and reported results. The influence of process parameters, like the scanning strategy, laser power, and scanning speed, on the microstructural grain morphology, are numerically evaluated.
Resonances of electromagnetic-induced transparency and electromagnetic-induced absorption at the transition with level momenta J=1/2 in unidirectional wave spectroscopy
Authors: Saprykin E G , Chernenko A A
Published: December 2021

The physical processes that form the saturated absorption resonance spectra on the atomic transition with level momenta J= 1/2 in the field of unidirectional waves of arbitrary intensities are investigated both analytically and numerically. It is shown that the narrow structures of the nonlinear resonance spectra (resonances of electromagnetic-induced transparency and absorption) and the processes forming them are determined by the direction of the light wave polarizations, degree of openness of the atomic transition, and the saturating wave intensity. The conditions under which the nonlinear resonance is exclusively coherent, due to the magnetic coherence of transition levels, are revealed.
Solving partial differential equations in deformed grids by estimating local average gradients with planes
Authors: Pohjonen Aarne
Published: December 2021

For constructing physical science based models in irregular numerical grids, an easy-to-implement method for solving partial differential equations has been developed and its accuracy has been evaluated by comparison to analytical solutions that are available for simple initial and boundary conditions. The method is based on approximating the local average gradients of a field by fitting equation of plane to the field quantities at neighbouring grid positions and then calculating an estimate for the local average gradient from the plane equations. The results, comparison to analytical solutions, and accuracy are presented for 2-dimensional cases.
Dissociation and recombination in the electrolyte flow model
Authors: Shobukhov A , Koibuchi H
Published: December 2021

We propose a one-dimensional model for the dilute aqueous solution of NaCl which is treated as an incompressible fluid placed in the external electric field. This model is based on the Poisson-Nernst-Planck system of equations, which also contains the constant flow velocity as a parameter and considers the dissociation and the recombination of ions. We study the steady-state solution analytically and prove that it is a stable equilibrium. Analyzing the numerical solutions, we demonstrate the importance of dissociation and recombination for the physical meaningfulness of the model.
Monte Carlo studies on shape deformation and stability of 3D skyrmions under mechanical stresses
Authors: Koibuchi H. , Hongo S. , Kato F. , El Hog S. , Diguet G. , Uchimoto T. , Diep H. T.
Published: December 2021

We study the stability/instability of skyrmions under mechanical stresses by Monte Carlo simulations in a 3D disk composed of tetrahedrons. Skyrmions emerge in chiral magnetic materials, such as FeGe and MnSi, under the competition of ferromagnetic interaction (FMI) and Dzyaloshinskii-Moriya interaction (DMI) and are stabilized by the external magnetic field. Recent experimental studies show that skyrmions are also stabilized/destabilized by uniaxial compressive stress perpendicular to or along the magnetic field direction. These phenomena are studied by using a 3D Finsler geometry (FG) model. In this 3D FG model, the DMI coefficient is automatically anisotropic by a geometrically implemented coupling of strains and electronic spins. We find that skyrmions are stabilized (destabilized) by extension (compression) stress along the direction of the applied magnetic field consistent with reported experimental data. This consistency implies that the 3D FG model successfully implements the magnetostrictive or magneto-elastic effect of external mechanical stresses on chiral magnetic orders, including the skyrmion configuration.
Group velocity dispersion in terahertz frequency combs within a generalized Maxwell-Bloch framework
Authors: Seitner Lukas , Popp Johannes , Riesch Michael , Haider Michael , Jirauschek Christian
Published: December 2021

As many molecules have their rotovibrational resonance frequencies in the mid-infrared or terahertz regime, efficient generation of corresponding frequency combs may lead to large progress in gas spectroscopy and sensing. Quantum cascade lasers (QCLs) are among the most promising candidates for a compact and cheap radiation source in this frequency range. This contribution presents a full-wave numerical solution of the Maxwell-Liouville-von Neumann equations, thus avoiding the limited applicability of the rotating wave approximation to moderate field strengths and spectral bandwidths. We include losses and chromatic dispersion of the optically active material in the QCL. The semiclassical approach uses the finite-difference time-domain (FDTD) method to derive update equations for the electric field, starting from the one-dimensional Maxwell equations. There, the optical full-wave propagation is coupled to the electronic quantum system via a polarization term that arises from the evolution of the density matrix. Furthermore, dispersion effects are considered through a classical polarization term and losses are introduced by a finite material conductivity. This work mainly focuses on the integration of group velocity dispersion (GVD) due to the bulk material and, if applicable, the waveguide geometry into the update equations. It is known to be one of the main degradation mechanisms of terahertz frequency combs, but has not yet been added to the existing full-wave solver. The implementation is carried out as Lorentz model and is applied to an experimentally investigated QCL frequency comb setup from the literature. The reported results are in good agreement with the experimental data. Especially, they confirm the need for dispersion compensation for the generation of terahertz frequency combs in QCLs.
Differential operators and reection group of type Dn
Authors: Nonkané Ibrahim , Lawson Latévi M.
Published: December 2021

In this note, we study the actions of rational quantum Olshanetsky-Perelomov systems for finite reflections groups of type D

n
. we endowed the polynomial ring C[x
1,..., xn
] with a differential structure by using directly the action of the Weyl algebra associated with the ring C[x
1,..., xn
]
W
of invariant polynomials under the reflections groups W after a localization. Then we study the polynomials representation of the ring of invariant differential operators under the reflections groups. We use the higher Specht polynomials associated with the representation of the reflections group W to exhibit the generators of its simple components.
Bearing friction effect on cup anemometer performance modelling
Authors: Alfonso-Corcuera D , Pindado S. , Ogueta-Gutiérrez M , Sanz-Andrés A
Published: December 2021

In the present work, the effect of the friction forces at bearings on cup anemometer performance is studied. The study is based on the classical analytical approach to cup anemometer performance (2-cup model), used in the analysis by Schrenk (1929) and Wyngaard (1981). The friction torque dependence on temperature was modelled using exponential functions fitted to the experimental results from RISØ report #1348 by Pedersen (2003). Results indicate a logical poorer performance (in terms of a lower rotation speed at the same wind velocity), with an increase of the friction. However, this decrease of the performance is affected by the aerodynamic characteristics of the cups. More precisely, results indicate that the effect of the friction is modified depending on the ratio between the maximum value of the aerodynamic drag coefficient (at 0° yaw angle) and the minimum one (at 180° yaw angle). This reveals as a possible way to increase the efficiency of the cup anemometer rotors. Besides, if the friction torque is included in the equations, a noticeable deviation of the rotation rate (0.5-1% with regard to the expected rotation rate without considering friction) is found for low temperatures.
On Harary energy and Reciprocal distance Laplacian energies1
Authors: Trigo Macarena
Published: December 2021

Let G be an graph simple, undirected, connected and unweighted graphs. The Reciprocal distance energy of a graph G is equal to the sum of the absolute values of the reciprocal distance eigenvalues. In this work, we find a lower bound for the Harary energy, reciprocal distance Laplacian energy and reciprocal distance signless Laplacian energy of a graph. Moreover, we find relationship between the Harary energy and Reciprocal distance Laplacian energies.
An Action Principle for Biological Systems
Authors: Summers Richard L.
Published: December 2021

In the analysis of physical systems, the forces and mechanics of all system changes as codified in the Newtonian laws can be redefined by the methods of Lagrange and Hamilton through an identification of the governing action principle as a more general framework for dynamics. For the living system, it is the dimensional and relational structure of its biologic continuum (both internal and external to the organism) that creates the signature informational metrics and course configurations for the action dynamics associated with any natural systems phenomena. From this dynamic information theoretic framework, an action functional can be also derived in accordance with the methods of Lagrange. The experiential process of acquiring information and translating it into actionable meaning for adaptive responses is the driving force for changes in the living system. The core axiomatic procedure of this adaptive process should include an innate action principle that can determine the system’s directional changes. This procedure for adaptive system reconciliation of divergences from steady state within the biocontinuum can be described by an information metric formulation of the process for actionable knowledge acquisition that incorporates the axiomatic inference of the Kullback’s Principle of Minimum Discrimination Information powered by the mechanics of survival replicator dynamics. This entropic driven trajectory naturally minimizes the biocontinuum information gradient differences like a least action principle and is an inference procedure for directional change. If the mathematical expression of this process is the Lagrangian integrand for adaptive changes within the biocontinuum, then it is also considered as an action functional for the living system.
A machine learning approach of finding the optimal anisotropic SPH kernel
Authors: Pereira Marinho Eraldo
Published: December 2021

It is presented a machine learning approach to find the optimal anisotropic SPH kernel, whose compact support consists of an ellipsoid that matches with the convex hull of the self-regulating k-nearest neighbors of the smoothing particle (query).
Numerical solution of generalized fractional Volterra integro-differential equations via approximation the Bromwich integral
Authors: Eshaghi Shiva , Ordokhani Yadollah
Published: December 2021

In this paper, we consider the generalized fractional Volterra integro-differential equations with the regularized Prabhakar derivative and represent the solution of this type of equations in the form of Bromwich integral in the complex plane. Then we select the hyperbolic contour as an optimal contour to approximate the Bromwich integral. Further, an example to show absolute errors for various parameters by using our numerical scheme on hyperbolic contour is given.
A comparison between current-based integral equations approaches for eddy current problems
Authors: Lucchini F , Marconato N
Published: December 2021

In this paper, a comparison between two current-based Integral Equations approaches for eddy current problems is presented. In particular, the very well-known and widely adopted loop-current formulation (or electric vector potential formulation) is compared to the less common J-φ formulation. Pros and cons of the two formulations with respect to the problem size are discussed, as well as the adoption of low-rank approximation techniques. Although rarely considered in the literature, it is shown that the J-φ formulation may offer some useful advantages when large problems are considered. Indeed, for large-scale problems, while the computational efforts required by the two formulations are comparable, the J-φ formulation does not require any particular attention when non-simply connected domains are considered.
Thermodynamic Analysis of Relaxation Model for Non-Equilibrium Phase Behavior of Hydrocarbon Mixtures
Authors: Indrupskiy I M , Chageeva P A
Published: December 2021

Mathematical models of phase behavior are widely used to describe multiphase oil and gas-condensate systems during hydrocarbon recovery from natural petroleum reservoirs. Previously a non-equilibrium phase behavior model was proposed as an extension over generally adopted equilibrium models. It is based on relaxation of component chemical potentials difference between phases and provides accurate calculations in some typical situations when non-instantaneous changing of phase fractions and compositions in response to variations of pressure or total composition is to be considered. In this paper we present a thermodynamic analysis of the relaxation model. General equations of non-equilibrium thermodynamics for multiphase flows in porous media are considered, and reduced entropy balance equation for the relaxation process is obtained. Isotropic relaxation process is simulated for a real multicomponent hydrocarbon system with different values of characteristic relaxation time using the non-equilibrium model implemented in the PVT Designer module of the RFD tNavigator simulation software. The results are processed with a special algorithm implemented in Matlab to calculate graphs of the total entropy time derivative and its constituents in the entropy balance equation. It is shown that the constituents have different signs, and the greatest influence on the entropy is associated with the interphase flow of the major component of the mixture and the change of the total system volume in the isotropic process. The characteristic relaxation time affects the rate at which the entropy is approaching its maximum value.
Parameter estimation for a simplified model of an electrolytic capacitor in transient regimes
Authors: Barbulescu Corneliu , Dragomir Toma-Leonida
Published: December 2021

The real capacitors’ behaviour in electric circuits modelled by a single capacity deviates from the ideal one. In order to find better compromises between precision and simplicity, different C-R-L models are used. In these models, C, R, L are called equivalent parameters and take constant values. Under these assumptions, the capacitors are modelled as lumped parameter subsystems although it is well known that the real capacitors are essentially distributed parameter systems. As highlighted in this paper, the capacitors are also time-variant subsystems. To prove this, we use two types of experimental data: data measured during the capacitor’s discharge process and data obtained from frequency characteristics. The article proposes two estimation methods of equivalent values for the model parameters C and R based on their time variance highlighted by the experimental data. The estimation methods use a system of equations associated with the discharging of capacitors, respectively, with the frequency characteristics via polynomial regression. The experiments were carried out with an electrolytic polymer capacitor rated 220 μF, 25 V, 2.5 A rms, 85 °C, designed mainly for energy storage and filtering, the results being confirmed by experiments performed on other similar capacitors.
Identification test of elements remaining in the barrel after firing, using Differential Scanning Calorimetry
Authors: Plachá A , Prasula P , Recko J
Published: December 2021

The issue of elements remaining in the barrel after firing is crucial both for the safe use of munition, and its reliability. These elements maybe categorized as being part of a metal case or a projectile (for example, fragments of broken connectors between a metal band and a projectile), or those associated with a propelling charge (like unburnt propellant grains). Both groups are undesirable and reflect the ammunition improper work. During own shooting tests of a 120 mm mortar ammunition the problem of unburnt elements remaining in the barrel occurred. The collected material was tested using one of the thermal analysis techniques - Differential Scanning Calorimetry - to characterize and to identify the tested sample.
Grid-characteristic numerical method for medical ultrasound
Authors: Beklemysheva Katerina , Vasyukov Alexey , Ermakov Alexey
Published: December 2021

Grid-characteristic method (GCM) is a fast and reliable numerical method that allows to model wave effects in viscoelastic media with high accuracy, including surface and contact waves. This research is dedicated to the application of GCM to the problem of medical ultrasound. Calculations for High-Intensity Focused Ultrasound (HIFU) were performed on 3D model statements for homogenous and inhomogeneous media, and a qualitative correspondence with experimental data was achieved. Numerical results include estimation of consumed energy (based on Maxwell viscosity model), velocity vector and stress tensor components. Various material parameters were considered, including relaxation time and inclusions of different types.
The theory of the chain fountain revisited
Authors: Anghel Dragos-Victor
Published: December 2021

We analyze the chain fountain effect-the chain siphoning when falling from a container onto the floor. We argue that the main reason for this effect is the inertia of the chain, whereas the momentum received by the beads of the chain from the bottom of the container (typically called “kicks”) plays no significant role. The inertia of the chain leads to an effect similar to pulling the chain over a pulley placed up in the air, above the container. In another model (the so called “scientific consensus”), it was assumed that up to half of the mechanical work done by the tension in the chain may be wasted when transformed into kinetic energy during the pickup process. This prevented the chain to rise unless the energy transfer in the pickup process is improved by the “kicks” from the bottom of the container. Here we show that the “kicks” are unnecessary and both, energy and momentum are conserved-as they should be, in the absence of dissipation-if one properly considers the tension and the movement of the chain. By doing so, we conclude that the velocity acquired by the chain is high enough to produce the fountain effect. Simple experiments validate our model and certain configurations produce the highest chain fountain, although “kicks” are impossible.
Digital literacy of indonesian prospective physics teacher: Challenges beyond the pandemic
Authors: Rahmawati A Z , Haryanto Z , Sulaeman N F
Published: December 2021

Pandemic covid-19 reinforces the needs of digital technology in all aspects, including education. Digital literacy skills become essential for all teachers and also prospective teachers. This study aims to find an overview of the digital literacy capabilities of prospective physics teachers. This study was a quantitative descriptive research with data collection using an instrument in a questionnaire that included 29 items from 4 aspects of digital literacy: Accessing content, creating content, transliteracy, and evaluating content. The sample consisted of 171 physics education students from 3 State Universities in Indonesia. The result showed the level of digital literacy in the moderate category. From the four aspects, creating content related to creating or presenting information on various digital platforms showed lower results than accessing content, transliteracy, and evaluating content. In a prospective science teacher curriculum, creating learning content on digital platforms needs to be developed. This research finding suggests that digital literacy needs to be enhanced during the prospective science teachers’ program.
Analysis of problem-solving ability of physics education students in STEM-based project based learning
Authors: Susanti E , Maulidah R , Makiyah Y S
Published: December 2021

This study is a quantitative descriptive. This study aimed to describe the problem-solving abilities of physics education students in the 2nd School Physics Laboratory course. The subjects of this study were 65 people consisting of 2 classes with the determination of the sample using the purposive sampling technique. Data collected is done through a problem-solving ability instrument which includes four indicators recognizing problems, planning solutions, solving problems, and evaluating. Based on the results of the data analysis, the conclusion is that students’ problem-solving abilities have been at a high level with a percentage average of 79. The caused by learning that applies STEM-based Project-Based Learning (PjBL). The learning helps develop students’ abilities in planning, communicating, solving problems, and making the right decisions from the problems given. This learning can train students’ skills in planning, organizing, negotiating, and making conventions about the issues of the task to be done, who is responsible for each task, and how the information will be collected and presented.
Physics e-module: A review and bibliometric analysis
Authors: Dewantara D , Sofianto E W N , Misbah  , Munawaroh D
Published: December 2021

The Covid-19 pandemic has brought significant changes in education and the tendency of face-to-face learning to be online. Therefore, several studies have developed e-modules to support learning, one of which is physics learning. This research is the result of a review based on a bibliometric analysis of the physics e-module. The data was obtained based on articles published in journals and proceedings on Google Scholar in 2020-2021, namely when the Covid-19 pandemic happened. These were selected via Publish or Perish (PoP) software. The data has been sorted until found 74 articles from 142 articles. The data were processed in depth using VOSviewer software. The results showed how the network, overlay, and density were between pieces. It also showed other information regarding the distribution of the authors and their affiliations. Based on this analysis, it was suggested that there is a need to strengthen collaboration between writers and research focused on students’ abilities and skills.
Development of student worksheets based on STEM approach to improve students’ critical thinking skills
Authors: Sutarto  , Prihatin J , Hariyadi S , Wicaksono I
Published: December 2021

The development of Worksheets based on the STEM approach pays attention to the elements of writing, the hierarchy of materials, and the selection of questions as an efficient and effective stimulus. This research aims to produce Worksheets based on the STEM approach that meets the feasibility of improving students’ critical thinking skills. The development model in this research refers to the 4D (four-D) research and development model by taking sample data from high school science students in the former Besuki Residency, namely Jember, Situbondo, Banyuwangi, and Bondowoso Regencies. The research instrument uses tests, observations, and documentation. The research results show that Worksheets based on the STEM approach meet the valid, practical, and effective criteria for improving students’ critical thinking skills. This research implies that the availability of Worksheets is expected for students to research teaching materials independently. In Worksheet, students will get materials, summaries, and assignments related to the material.
The effect of physics learning using ardouno uno based media on higher-order thinking skills
Authors: Matsun  , Boisandi  , Sari I N , Hadiati S , Saputri D F
Published: December 2021

The purpose of this study was to determine the effectiveness of contextual media with Arduino Uno-based media on students’ higher-order thinking skills on density material. The population of this research is class XII IPA MAN 1 Pontianak totaling six classes, with samples of class XII IPA A and class XII IPA B. This study is quasi-experimental with a pretest-posttest group design—sampling with a simple random technique to determine the experimental and control classes. The data collection technique used is a test in the form of pretest and post-test questions. The data analysis technique used is the one-party t-test based on the sig value and the normalized gain (N-gain). The results of research data analysis showed that contextual learning media with media based on Arduino Uno had a positive effect and improved students’ higher-order thinking skills than students who used conventional media. It is indicated by the results of the t-test with a value of sig. The post-test score is 0.001, and the results of the improvement test with the N-gain of the experimental class are in the medium category, higher than the control class category, namely low. So that learning physics using learning media based on Ardouno Uno has a positive effect and can improve students’ Higher Order Thinking skills.
Electronic thermodynamics teaching materials based on authentic learning to practice students’ problem-solving skills: Aspects of validity
Authors: Rizki M , Wati M , Misbah M
Published: December 2021

The purpose of this study was to describe the validity of authentic learning-based electronic thermodynamic teaching materials to train students’ problem-solving skills during the covid-19 pandemic. The model used in this study was the ASSURE development model, which only reached the third stage, namely Selection of Media and Materials. The validation of teaching materials was assessed by three validators consisting of two physics education academics and one practitioner. Based on the validation results, it was found that the authentic learning-based electronic thermodynamic teaching material for training students’ problem-solving skills was declared valid with a value of 3.14. Appropriate teaching materials can then be used in schools’ teaching and learning processes and tested for practicality and effectiveness.
Accelerating teacher career through improving competence in scientific publications: Physics teacher perspectives
Authors: Admoko S , Supardi Z A I , Wasis  , Suprapto N , Realita A , Prahani B K , Muhayatin S , Irfa’i M , Dakri  , Suyanto  , Hati H S , Misbah M
Published: December 2021

In promotion of teachers career to a higher level are required to write scientific papers. This study aims to describe the physics teacher’s perspective on the promotion process they have experienced so far and the obstacles they face. This research is a descriptive research, data collection through questionnaire and information deepening is done through interviews. The sample of this research is 73 physics teachers. Based on the results of data analysis, it can be seen that more than 65% of physics teachers have difficulty in fulfilling scientific publication requirements for promotion, 85% of respondents have done classroom action research (CAR), but only about 44% have published in the form of scientific articles. In general, teachers have experience in conducting CAR, but they still lack experience in writing scientific articles. Most physics teachers expect local schools and education offices to cooperate with universities to organize training and mentoring of scientific publications. This study can be concluded that the main obstacle to the promotion of physics teachers is caused by the low ability to carry out scientific publications. The results of this study are expected to provide consideration to stakeholders in making decisions and actions related to teacher promotion, especially regarding the mandatory requirements for scientific publications.
A Simple Brushless Motor and Propeller Test Stand for Experiment from Home
Authors: Prasetiyo Erwan Eko
Published: December 2021

A brushless motor and propeller test stand is used to test brushless motors and propellers. This testing instrument is still only available in research laboratories. Students and researchers are unable to use laboratory facilities because of the Covid-19 epidemic, thus students must be able to do tests independently from home. Purchasing this testing instrument would be too expensive for students. It is essential to construct a brushless motor and propeller testing instrument at home using simple components that are easy to get on the marketplace. The design concept reads force data using a loadcell sensor and an HX711 driver, and current and voltage data with an INA 219 sensor. The brushless motor’s rotational speed is controlled by a potentiometer. Force, current, voltage, and power are all examples of test results data. A 16×2 LCD is used to show data immediately. Data is also transmitted via a USB connection to a computer device for storage or additional analysis. This study proposes a simple brushless motor and propeller test stand that can measure forces from 0 gf to 1000 gf with an error rate of 0.72 %. The power that can be read ranges from 0 mW to 18960 mW, with a 0.59 % error rate.
Design and Performance Analysis of 600 W On-Grid Solar Power Plant System based on Maximum Power Point Tracking (MPPT)
Authors: Yuniarti Nurhening , Wardhana Alex Sandria Jaya , Saputra Bagas Woro
Published: December 2021

This research aimed to make, test, and analyse the performance of 600 W on-grid solar power plant system based on maximum power point tracking (MPPT). This research used a developmental research method with the ADDIE model that was developed by Robert Maribe Branch. The results obtained data that the average power that was produced and distributed to the PLN grid reached 22.5 W with 95.67% efficiency from the grid-tie inverter usage.
Development Mobile Application Android Based for Sensor and Transducer
Authors: Hatmojo Y I , Azis S M
Published: December 2021

The aims of this research are: (1) producing a mobile applications android based for sensor and transducer field of study on vocational education; (2) know the quality of the product mobile applications android based for sensor and transducer field study on vocational education. The method used is the Software Development Life Cycle with the Waterfall model. The stages in Waterfall model are: (1) requirements definition; (2) system and software design; (3) implementation and unit testing; (4) integration and system testing; (5) operation and maintenance. The black box test results show the performance of Sensor application software can all function properly. While the results of the compatibility test show the application can run on various android systems (at least Android 4.2).
Information System for Disaster Mitigation Using Google Data Traffic
Authors: Jati Handaru , Mahali Muhammad Izzuddin , Agung Dewanto Satriyo
Published: December 2021

The Head of the Data Information Center and Public Relations of the National Disaster Management Agency predicts the potential for forest fires in 2018 will increase. The areas that are burned are border areas, both provincial/district/city borders because border areas are poorly supervised. This study aims to (1) Develop an Information System that can be used for Disaster Mitigation Using Google Data Traffic (2) Ensure that the developed Information System is suitable for use for Disaster Mitigation Using Google Data Traffic to obtain accurate traffic data. Google Data Traffic is a giant database used by the Google company to provide real-time traffic information through the Google Maps application. Google Maps uses multiple iterations of satellite cameras and uses Google Earth to map traffic including congestion information and the shortest possible path alternatives. The development method chosen is the Rational Unified Process (RUP). This research uses several methods in data collection including observation, interviews, and questionnaires. Interviews were conducted with prospective users of the application, namely firefighter drivers and people in disaster-prone areas. Questionnaires are used to provide a set of questions to respondents. In the determination test, the recall and precision values are calculated from the data generated by the developed system. While the function test uses descriptive data analysis techniques with the percentage feasibility formula. This research produces an application that can assist firefighters in carrying out their daily duties to be more effective and efficient and the test results on this application show that it is declared feasible in terms of efficiency, performance and compatibility.
Improving online learning interactivity with 3D virtual classroom models
Authors: Wardani R , Jati H , Nurkhamid  , Indrihapsari Y , Setialana P , Budiyanto A M , Ardiansyah M N
Published: December 2021

The world of education is experiencing a very significant impact of the Covid-19 pandemic. Online learning is a solution in overcoming learning limitations due to social distancing. Researchers developed a 3d virtual classroom using a Minecraft model to increase online learning interactivity. The 3 dimensional virtual classroom model design that has been developed has received respondents’ acceptance of 90.00% in the “Very Eligible” category. Testing the 3 virtual classroom features feature got a percentage of 90.83% with the “Very Eligible” category to produce a sense of presence. In the interactivity test, character interaction is 89.17% in the “Very Eligible” category. The effectiveness of online learning continuity using the 3D virtual classroom model tested gets 89.17% with the “Very Eligible” category. In addition, the test uses an average score of SUS (System Usability Scale) of 73.67, so it can be concluded that the 3D virtual classroom model is “acceptable” as an online learning medium.
Evaluating UI in Digital Skills Training: Human Centered-Design approach from UI Sanbercode Bootcamp
Authors: Fiducia  , Suprapto
Published: December 2021

Sanbercode is a digital skill training program, which can be studied by various classes of training. In the Covid-19 pandemic, much is felt: health, economics, to learning activities. These conditions require learning activities to be carried out at home. The purpose of this training is to enhance a person’s digital abilities or digital skilss. Sanbercode training is done online the web that is easy to access, it is hoped can take place more interactive, real, and fun. The approach applied to UI involves human centered-design. Found eight issues on the features consistent with human centered-design and conducted heuristic evaluations by evaluators. The results show a decline in the number following improvement solutions.
Item Selection on The Moodle-Based Computerized Adaptive Test
Authors: Haryanto  , Neng-Shu Y , Hadi S , Ali M , Husna AF , Wardhana ASJ
Published: December 2021

In this industrial era, all areas of life have been entered. There are five central issues that support performance, namely numerical physical devices, production tools, programs, interfaces, and networks. The Modular Object-Oriented Dynamic Learning Environment (Moodle) in order to support Industrial technology has been equipped with adaptive test facilities. Adaptive Moodle can be used to organize a communicative and interactive test process because of the communication features (chat, messaging, or forum). In addition, Adaptive Moodle can be used to administer online tests. Adaptive tests are tests whose quiz presentations will adjust to the user’s abilities. The results of the research that has been carried out regarding the selection of items on the Moodle-based computerized adaptive test (CAT) were obtained: (1) The Moodle adaptive test worked successfully in accordance with the research objectives, (2) Based on user responses, the selection of items on the Moodle adaptive test items had worked well for the exam, (3) The Moodle adaptive test can run according to its function, namely adaptive to the user’s ability.