Computer Simulation Model Research Articles

Simulation Modeling of an Inhomogeneous Medium, in Particular: Round, Triangular, Square Shapes

The article analyzes and develops an algorithm for the operation of the powder backfill process using vibration oscillations. The results of the study make it possible to predict the main properties of particles of any shape. The developed computer simulation model also provides for the superposition of horizontal and vertical oscillations. It should be noted that the difference between them is that the main one for the implementation of horizontal oscillations is the X - coordinate, and for vertical ones – the Y - coordinate. It is also important that the model algorithm provides for simultaneous application of vibration oscillations, which makes it possible to study the influence of the history of the backfill process. It should also be noted that in this scientific study, a number of experiments were conducted, the change in porosity during the imposition of oscillations was studied, and graphs of the obtained experimental dependences were constructed. Porosity from the main parameters of the bunker, in particular: width and height, is also studied. The obtained results made it possible to record the optimal porosity of the backfill with a reliable deviation error (± 1%).

Computer Simulation Modeling of an Inhomogeneous Medium with Ellipse-Shaped Irregular Elements

The article substantiates the main possibilities of filling with irregular bodies, and provides a visual analysis of the parameters formed as a result of structures. It was found out that the form factor acts as the main indicator of the characteristic parameter of changes in the structure and all other parameters of an inhomogeneous medium. It was also found out that when filling a container with irregular ellipsoid elements, the conditions for non-opening (one-way contact) must be met. The obtained calculations of the form factor show the minimum value of the average coordination number of an inhomogeneous medium. This allows us to assert and predict reliable modelling results (± 2-3%). It is also important that the developed simulation model for modelling an inhomogeneous medium using an irregular (ellipsoid) shape of elements can significantly reduce the time spent on conducting field experiments, as well as simulate irregular elements with different shape factors.

Impact of constrained humeral liner on impingement-free range of motion and impingement type in reverse shoulder arthroplasty using a computer simulation

Dislocation is a major complication of reverse total shoulder arthroplasty (RSA). Humeral liner may be changed to the constrained type when stability doesn't improve by increasing glenosphere size or lateralization with implants, and patients, particularly women with obesity, have risks of periprosthetic instability that may be secondary to hinge adduction on the thorax, but there are few reports on its impact on the range of motion (ROM). This study aimed to determine the influence of humeral liner constraint on impingement-free ROM and impingement type utilizing an RSA computer simulation model. A virtual simulation model was created using 3D measurement software for conducting a simulation study. This study included twenty-five patients with rotator cuff tears and rotator cuff tear arthropathy. Impingement-free ROM and impingement patterns were measured during flexion, extension, abduction, adduction, external rotation, and internal rotation. Four different simulations of 2×2 were performed in each of the 25 cases, a total of 100 simulations: Glenosphere (38mm normal type vs. lateralized type) and humeral liner constraint (normal type vs. constrained type). There were four combinations: normal glenosphere and normal humeral liner, normal glenosphere and constrained humeral liner, lateralized glenosphere and normal humeral liner, and lateralized glenosphere and constrained humeral liner. Significant differences were found in all impingement-free ROM in one-way ANOVA (abduction: p=0.01, adduction: p<0.01, flexion: p=0.01, extension: p=0.02, external rotation: p<0.01, and internal rotation: p<0.01). Tukey's post-hoc tests showed that the impingement-free ROM was reduced during abduction, external rotation, and internal rotation with the combination of normal glenosphere and constrained humeral liner compared to the other combinations, and improved by glenoid lateralization compared to the combination of the lateralized glenosphere and constrained humeral liner. In the impingement pattern, Pearson's chi-squared test showed significantly greater proportion of impingement of the humeral liner into the superior part of the glenoid neck in abduction occurring in the combination of normal glenosphere and constrained humeral liner group compared to the other groups (p<0.01). Bonferroni post-hoc tests revealed that the combination of normal glenosphere and constrained humeral liner was significantly different from that of lateralized glenosphere and constrained humeral liner (p<0.01). Using constrained liners resulted in early impingement on the superior part of the glenoid neck in the normal glenosphere, whereas glenoid lateralization increased impingement-free ROM. This RSA computer simulation model demonstrated that constrained humeral liners led to decreased impingement-free ROM. However, using lateralized glenosphere improved abduction ROM.

Analysis of technical characteristics of typical lower limb balance movements in Tai Chi: a cross-sectional study based on AnyBody bone muscle modeling.

Tai Chi is an excellent traditional Chinese physical fitness exercise, and its unique balancing movements are very important for improving human balance. In this study, the two most representative Tai Chi balance movements, "knee lift balance" and "leg stirrup balance", were selected to establish the lower limb bone muscle model of Tai Chi balance movements by using computer simulation modeling technology, aiming to analyze the characteristics of the lower limb movement mechanisms of typical balance movements, to provide a quantitative theoretical basis for improving the scientific level of Tai Chi. A total of 16 subjects were recruited for this study. the BTS three-dimensional motion capture system and three-dimensional force platform were used for motion data acquisition, the physiological electromyographic signals were collected using BTS surface electromyography, and the lower limb bone muscle model of Tai Chi balance movements was established by AnyBody human simulation. In the knee lift balancing movement, the balance leg hip abduction/adduction angle, hip flexion/extension moment, and the strength of the rectus femoris muscle, biceps femoris short capitis, and iliacus muscle of the amateur group was significantly smaller than that of the professional group (P<0.01). In the leg stirrup balance movement, the knee flexion/extension angle of the balancing leg in the amateur group was significantly greater than that in the professional group (P<0.01), and the hip flexion/extension angle, hip inversion/abduction angle, knee flexion/extension moment, hip flexion/extension moment, the strength iliacus, gluteus maximus, and obturator internus were significantly smaller than those in the professional group (P<0.01). The integral EMG of the biceps femoris of the support leg in the amateur group was significantly smaller than that of the professional group (P<0.01). The integral EMG of the lateral femoral muscle of the balance leg was significantly smaller than that of the professional group (P<0.01). In this study, we found that the balancing leg of the balancing movement has a larger hip joint angle, the stirrup balancing knee joint angle is smaller, and the hip and knee joint moments are larger. This is related to joint activity and muscle activation, and amateurs should pay attention to increasing the range of motion of the hip joint and decreasing the range of motion of the knee joint when practicing to better stimulate exercise of the lower limb joints. In addition, the practice of balancing movements should strengthen the iliacus muscle, which plays an important role in maintaining the stable balance of the lower limbs, and strengthen the knee flexor and extensor muscles and hip adductor/abductor muscles of the balancing leg, thus promoting the stability of the balancing leg movements.

An investigation into the effects of contouring process parameters on the up-skin surface characteristics in laser powder-bed fusion process

Laser powder-bed fusion (L-PBF) additive manufacturing is reshaping how parts are designed and built in the aerospace, automotive, biomedical, and other industries. However, in several applications, the quality of the components in terms of surface roughness, density, and mechanical properties is not comparable to that of parts made by conventional manufacturing processes. Multiple process parameters and associated uncertainties strongly influence the properties of L-PBF built parts. This study aims to understand the effects of contouring process parameters on the formation of up-skin surfaces and roughness variability in an inclined build scenario. Through Design of Experiment (DOE), the influence of the contour process parameters, such as the laser power, scanning speed, contouring offset, and incline angle (θ, between 30° and 60°), on upward-facing surfaces is investigated. Furthermore, a comprehensive multi-physics Computational Thermo-fluid model and Discrete Element Method (DEM) simulation framework is developed to shed light on how contouring scans affect the morphology of the upward-facing surface. The developed thermo-fluid model framework is used to perform multi-track multi-layer simulations of an L-PBF process. Numerical data suggests that a higher laser power enlarges the melt-pool size providing sufficient fusion at the border, hence, improving the density of up-skin regions. A higher density may primarily contribute to a better surface finish for up-skin features. The experimental result analysis shows that in the tested slope range (30° ≤ θ ≤ 60°), the up-skin surface roughness exacerbates with the increase of the incline angle and the scanning speed. On the other hand, a higher laser power will result in better surface finishes. The findings also indicate that a higher linear energy density (LED = Power/Speed) for contour scans is more favourable for the range of parameters tested in this study. Within the range of studied contouring process parameters, the maximum and minimum of average roughness (Ra) values for up-skin surfaces are 21.2 ± 2.9 µm and 8 ± 0.6 µm, respectively.

Preface

Conference COMAT deals with recent trends in structural materials that cover production technologies (casting, forging, rolling, additive manufacturing...), heat and thermo-mechanical treatments, computer modelling and physical simulations and materials characterisation. COMAT started in 2010. Therefore, we celebrated already 12th anniversary of the conference the last year. The event was organized by traditional tandem COMTES FHT Inc. and TANGER Ltd. We had high expectations for this meeting after two years of COVID restrictions. Unfortunately, many of them remained valid till the conference took place and we had very narrow range of foreigner participants and rather low number of participants in comparison with the previous years. Lower number of participants lead to single session conference, which in turn resulted in very friendly and constrictive atmosphere, when all sessions had much more audience and discussions, than it was in the previous years, when parallel sessions systems was implemented. For COMAT 2022 we agreed for the first time on selected paper publication in Materials journal, leading to smaller amount of papers to be found in these proceedings, but we still hope the readers will find these proceedings interesting and inspiring. These articles were reviewed by 20 experts.We are looking forward to seeing you all personally at COMAT 2024.

Which programmes and policies across health and community settings will generate the most significant impacts for youth suicide prevention in Australia and the UK? Protocol for a systems modelling and simulation study

IntroductionSuicide is a leading cause of mortality among young people aged 15–24 globally. Despite the deployment of comprehensive suicide prevention strategies, we still do not know which interventions, for which...

Modeling of Resistance Spot Welding Using FEM

The resistance spot welding process is significant for joining materials in the automotive industry because it offers high speed and can be easily automated. Recently, there has been a demand in the automotive industry to reduce vehicle weight to improve fuel efficiency. Aluminium alloys are considered a viable alternative for auto-body materials to meet this requirement. It not only helps enhance fuel efficiency but also addresses the issue of vehicle corrosion. However, joining aluminium through resistance spot welding presents serious challenges compared to steel. One significant difficulty arises from the faster deterioration of electrodes. Aluminium alloys possess high electrical and thermal conductivity, significant shrinkage during solidification, and a natural oxide coating. These features make the spot welding process for aluminium alloys notably distinct. When exposed to high temperatures, aluminium undergoes a chemical reaction with the copper alloy found in the electrode material. This results in the unpredictable removal of material from the electrode surfaces, causing wear and significantly reducing the lifespan of the electrode during spot welding of aluminium alloys. This decrease in electrode tip longevity poses a significant drawback in weldability, as the durability of the electrode tip significantly affects its suitability for automotive applications. Due to the rapid nature of the process, obtaining crucial information, such as the transient distribution of current density and temperature through experimental methods, becomes challenging. Therefore, this study aims to develop an integrated computer simulation model using the finite element method to analyze the resistance spot welding process of aluminium alloys. Multiple calculations were performed considering different welding currents, weld times, electrode forces, and various surface conditions of the aluminium sheets. The simulation considers the nonlinear, temperature-dependent, thermo-physical properties of the materials. Interestingly, it was observed that in most cases, the nugget diameter is formed within a short time frame of 0.02 to 0.04 seconds, and further application of welding current primarily increases the heating of the electrode face. Moreover, the aluminium sheets’ initial surface condition significantly influences the nugget’s formation. Several other conclusions have been drawn as a result of this study.

Compression of a confined semiflexible polymer under direct and oscillating fields.

The folding transition of biopolymers from the coil to compact structures has attracted wide research interest in the past and is well studied in polymer physics. Recent seminal works on DNA in confined devices have shown that these long biopolymers tend to collapse under an external field, which is contrary to the previously reported stretching of the chain. In this work, we capture the compression of a confined semiflexible polymer under direct and oscillating fields using a coarse-grained computer simulation model in the presence of long-range hydrodynamics. In the case of a semiflexible polymer chain, the inhomogeneous hydrodynamic drag from the center to the periphery of the coil couples with the chain bending to cause a swirling movement of the chain segments, leading to structural intertwining and compaction. Contrarily, a flexible chain of the same length lacks such structural deformation and forms a well-established tadpole structure. While bending rigidity profoundly influences the chain's folding favorability, we also found that subject to the direct field, chains in stronger confinements exhibit substantial compaction, contrary to the one in moderate confinements or bulk where such compaction is absent. However, an alternating field within an optimum frequency can effectuate this compression even in moderate or no confinement. This field-induced collapse is a quintessential hydrodynamic phenomenon, resulting in intertwined knotted structures even for shorter chains, unlike other spontaneous knotting experiments where it happens exclusively for longer chains.

Noise Abatement Approach Using Computer Simulation Model for Urban Indian Road of a Tier-2 City

Noise pollution is a major problem nowadays. In urban context, road traffic is the main source of noise pollution. People directly exposed to road traffic noise suffer from moderate to severe annoyance, headache, stress, feeling of exhaustion, and reduced work performance efficiency. As the sources and severity of noise pollution continue to grow, new approaches are needed to reduce the exposure. In this research, noise abatement has been investigated using a computer simulation model (SoundPLAN essential 4.0). Noise maps were developed using SoundPLAN essential 4.0 software. Noise maps are very beneficial to identify the impact of noise pollution. Data required for mapping are noise data (LAeq), road inventory data, geometric features of mapping area, category wise traffic counts, category wise vehicle speed, meteorological data such as wind velocity, humidity, temperature, air pressure. LAeq observed on all locations of the Central zone of Surat city was greater than the prescribed central pollution control board (CPCB) limits during day time and night time. This paper is focused on using acoustic software for the simulation and calculation methods of controlling the traffic noise. According to the characteristics of traffic noise and the techniques of noise reduction, road traffic noise maps were developed using SoundPLAN essential 4.0 software to predict the scope of road traffic noise. On this basis, four reasonable noise control schemes were used to control noise, and the feasibility and application effect of these control schemes can be verified by using the method of simulation modelling. The simulation results show that LAeq is reduced by up to 5 dB(A). The excess noise can be efficiently reduced by using the corresponding noise reduction methods.

Beyond Chainmail: Computational Modeling of Discrete Interlocking Materials

We present a method for computational modeling, mechanical characterization, and macro-scale simulation of discrete interlocking materials (DIM)---3D-printed chainmail fabrics made of quasi-rigid interlocking elements. Unlike conventional elastic materials for which deformation and restoring force are directly coupled, the mechanics of DIM are governed by contacts between individual elements that give rise to anisotropic deformation constraints. To model the mechanical behavior of these materials, we propose a computational approach that builds on three key components. ( a ): we explore the space of feasible deformations using native-scale simulations at the per-element level. ( b ): based on this simulation data, we introduce the concept of strain-space boundaries to represent deformation limits for in- and out-of-plane deformations, and ( c ): we use the strain-space boundaries to drive an efficient macro-scale simulation model based on homogenized deformation constraints. We evaluate our method on a set of representative discrete interlocking materials and validate our findings against measurements on physical prototypes.

An application of artificial neural networks for solving fractional higher-order linear integro-differential equations

This ongoing work is vehemently dedicated to the investigation of a class of ordinary linear Volterra type integro-differential equations with fractional order in numerical mode. By replacing the unknown function by an appropriate multilayered feed-forward type neural structure, the fractional problem of such initial value is changed into a course of non-linear minimization equations, to some extent. Put differently, interest was sparked in structuring an optimized iterative first-order algorithm to estimate solutions for the origin fractional problem. On top of that, some computer simulation models exemplify the preciseness and well-functioning of the indicated iterative technique. The outstanding accomplished numerical outcomes conveniently reflect the productivity and competency of artificial neural network methods compared to customary approaches.

Adding Tibial Tuberosity Medialization to Medial Patellofemoral Ligament Reconstruction Reduces Lateral Patellar Maltracking During Multidirectional Motion in a Computational Simulation Model

To determine whether adding tibial tuberosity medialization to medial patellofemoral ligament (MPFL) reconstruction reduces lateral patellar maltracking during a dynamic multidirectional activity and to investigate when medial patellofemoral contact pressures are elevated during daily activities, such as squatting. Seven computational models representing knees with patellar instability, including lateral patellar maltracking, were evaluated following simulated MPFL reconstruction (bisect offset index > .75). Tibial tuberosity medialization was added to MPFL reconstruction for each model. Patellar tracking during multidirectional motion was evaluated by simulating pivot landing. Analysis of pivoting focused on early flexion (5° to 40°). Patellofemoral contact pressures during daily function were evaluated by simulating knee squatting. Data were analyzed with paired comparisons between MPFL reconstruction with and without tuberosity medialization. The patella dislocated during pivoting for 2 models with an isolated MPFL reconstruction and for 1 model including tibial tuberosity medialization. Adding tibial tuberosity medialization to MPFL reconstruction significantly decreased bisect offset index by ∼0.1 from 5° to 40° (P < .03). For knee squatting, medializing the tibial tuberosity significantly increased maximum medial contract pressure by ∼0.5 MPa from 30° to 85° (P < .05) but did not significantly influence maximum lateral pressure. In this study of simulated multidirectional motion, MPFL reconstruction did not sufficiently constrain the patella for some knees. Adding tibial tuberosity medialization to MPFL reconstruction in these models reduced lateral patellar maltracking during multidirectional motion but increased pressure applied to medial cartilage during squatting. After establishing the influence of tibial tuberosity medialization on patellar maltracking for an idealized population, as was done in the current study, future simulation studies can be performed to better determine the anatomical characteristics of patients for whom tibial tuberosity medialization is needed to reduce the risk of postoperative patellar maltracking.

Dimerization of European Robin Cryptochrome 4a.

Homo-dimer formation is important for the function of many proteins. Although dimeric forms of cryptochromes (Cry) have been found by crystallography and were recently observed in vitro for European robin Cry4a, little is known about the dimerization of avian Crys and the role it could play in the mechanism of magnetic sensing in migratory birds. Here, we present a combined experimental and computational investigation of the dimerization of robin Cry4a resulting from covalent and non-covalent interactions. Experimental studies using native mass spectrometry, mass spectrometric analysis of disulfide bonds, chemical cross-linking, and photometric measurements show that disulfide-linked dimers are routinely formed, that their formation is promoted by exposure to blue light, and that the most likely cysteines are C317 and C412. Computational modeling and molecular dynamics simulations were used to generate and assess a number of possible dimer structures. The relevance of these findings to the proposed role of Cry4a in avian magnetoreception is discussed.

Three-dimensional spinal shape changes during daily activities

Motivation:Intuitive assessment of spinal motion poses a tremendous challenge to both physicians and computer modelers. On the one side, medically detailed analyses of spinal shapes, such as computer tomography or X-ray images, are usually subject to static boundary constraints, thereby omitting dynamic information. On the other side, complex computer simulations often lack proper calibration aside from few control points, particularly regarding the three-dimensional arrangement of the spinal column and its idiomotion. Purpose:Here, we investigate whether the full three-dimensional changes in spinal shape over time can be concisely detected and depicted. Further, we assess which parts of the spine undergo significant changes during various daily activities. Methods:We utilize a set of previously published motion capture data from the spinous processes (sacrum up to vertebra C7) of 17 healthy individuals performing the daily tasks of standing, walking, stair climbing, sitting down, and lifting. These three-dimensional, time-dependent marker positions were approximated by a Bézier curve at each time instant. The curves’ characteristics, i.e.curvature and torsion, were calculated and juxtaposed for each individual and each activity over time. A statistical parametric mapping revealed significant changes in spinal shape. Results:We found the individual spinal shape characteristics being recognizably preserved during all activities. The walking task did not significantly alter the spinal curvature, while sitting and forward bending significantly altered the lumber and whole spine curvature, respectively. Torsion did not show any significant alterations. Conclusion:Based on these results, we suggest that individualized dynamic information on spinal shapes can improve (i) the evaluation of (healthy) motion characteristics, (ii) the detection of pathologies, and (iii) individualized computer simulation models.

A Boltzmann Electron Drift Diffusion Model for Atmospheric Pressure Non-Thermal Plasma Simulations

We introduce a fluid computational model for the numerical simulation of atmospheric pressure dielectric barrier discharge plasmas. Ion and neutral species are treated with an explicit drift diffusion approach. The Boltzmann relation is used to compute the spatial distribution of electrons as a function of the electrostatic potential and the ionic charge density. This technique, widely used to speed up particle and fluid models for low-pressure conditions, poses several numerical challenges for high-pressure conditions and large electric field values typical of applications involving atmospheric-pressure plasmas. We develop a robust algorithm to solve the non-linear electrostatic Poisson problem arising from the Boltzmann electron approach under AC electric fields based on a charge-conserving iterative computation of the reference electric potential and electron density. We simulate a volumetric reactor in dry air, comparing the results yielded by the proposed method with those obtained when the drift diffusion approach is used for all charged species, including electrons. We show that the proposed methodology retains most of the physical information provided by the reference modeling approach while granting a substantial advantage in terms of computation time.

SIMULATION OF NITROGEN BALANCE UNDER SUB-SURFACE DRAINAGE CONDITIONS AT THEHRI MUKTSAR PUNJAB, USING THE DNDC MODEL V. 9.5

Aim of the study: The aim of the study is DNDC model simulation for nitrogen balance in rice-wheat cropping system. Material and methods: The DeNitrification-DeComposition (DNDC) model is a computer simulation model for the biogeochemistry of carbon and nitrogen in agro ecosystems that takes a process-oriented approach. The DNDC model version 9.5 (http:// www.dndc.sr.unh.edu) was selected for estimating nitrogen balance. The model consists of two modules. The first component simulates moisture, soil temperature, pH, and substrate concentration, which are determined by ecological parameters such as soil, climate, anthropogenic activities, and vegetation. It consists of sub-models for plant growth, decomposition, and soil climate. The second module predicts the emission of gasses from plant-soil systems such as methane (CH4), nitrous oxide (N2O), nitrogen oxide (NO), dinitrogen (N2), ammonia (NH3), and carbon dioxide (CO2). The model includes empirical equations developed from laboratory studies and is based on the classical laws of chemistry, physics, and biology. The empirical equations included parameterizing specific biochemical or geochemical reactions. The entire model bridges the primary ecological drivers with the biogeochemical cycles of C and N (see: Figures 1 and 2). Results and conclusions: This study used the DNDC model to estimate nitrogen balance in the study area. A calibrated and validated DNDC model was used to simulate NO3-N loss in runoff and leachate from a rice–wheat cropping system from 2018 to 2020. The total nitrogen balance estimated by the DNDC model was negative (–99.44 kg N ha–1 yr–1) and positive (69.1 kg N ha–1 yr–1) for rice and wheat cropping systems, respectively, in the study area.

Strategies for Controlling a Whole-Body Task With Uncertain Initial Conditions: Application to the Upstart on Bars.

The upstart is commonly used on bars in artistic gymnastics following a release and regrasp skill, where the gymnast will perform a flighted element before catching the bar. The variability of the flighted element leads to varying initial conditions prior to the upstart. The aim of the study was to understand how technique can be manipulated in order to ensure success at the task despite this variability. More specifically, the study aimed to quantify the ranges of initial angular velocity a gymnast could cope with in an upstart using (a)a fixed timing technique, (b)with one additional parameter to modify timings as a function of initial angular velocity, and (c)a further additional parameter to extend the range. Relationships were established, using computer simulation modeling, between the movement pattern parameters, which defined the technique, and the initial angular velocity of the upstart. A two-parameter relationship outperformed both the one-parameter relationship and the fixed timing solution in terms of the range of initial angular velocities the model could cope with. One of the two parameters governed the time by which the initiation of the shoulder extension should be reduced as a function of increased initial angular velocity, and the other parameter performed the same function for the remaining timing parameters at the hip and shoulder. The present study suggests that gymnasts, and, therefore, humans, may be able to modify movement patterns to cope with uncertain initial conditions using a relatively small number of parameters.

Numerical Study of the Local Scouring Process and Influencing Factors of Semi-Exposed Submarine Cables

Local scouring might result in the spanning of submarine cables, endangering their mechanical and electrical properties. In this contribution, a three-dimensional computational fluid dynamics simulation model is developed using FLOW-3D, and the scouring process of semi-exposed submarine cables is investigated. The effects of the sediment critical Shields number, sediment density, and ocean current velocity on local scouring are discussed, and variation rules for the submarine cables’ spanning time are provided. The results indicate that three scouring holes are formed around the submarine cables. The location of the bottom of the holes corresponds to that of the maximum shear velocity. The continuous development of scouring holes at the wake position leads to the spanning of the submarine cables. The increase in the sediment’s critical Shields number and sediment density, as well as the decrease in the ocean current velocity, will extend the time for maintaining the stability of the upstream scouring hole and retard the development velocity of the wake position and downstream scouring holes. The spanning time has a cubic relationship with the sediment’s critical Shields number, a linear relationship with the sediment density, and an exponential relationship with the ocean current velocity. In this paper, the local scouring process of semi-exposed submarine cables is studied, which provides a theoretical basis for the operation and maintenance of submarine cables.

Attitudes and beliefs toward physics: A mini review

A mini review of attitudes and beliefs toward physics has been carried out. The purpose of this study was to address aspects that influence attitudes and beliefs toward physics and various learning models that can increase attitudes and beliefs toward physics. The method used in this study was literature review. Literature review was done by searching for keywords, i.e.: attitudes towards physics and beliefs towards physics. This keyword search was done through Google Scholar, Base, and Core search engines. We have obtained 25 articles that matched the keywords and have been screened with the limitation of the year of publication, namely the last 10 years. Through this literature review it can be obtained that physics attitudes and beliefs were influenced by gender and personality, grade level, type of school, and age. Contradictions regarding aspects that influence attitudes and beliefs about physics occur in the gender aspect. Various learning methods to improve attitudes and beliefs about physics were cooperative learning models with jigsaw, Science Technology Engineering and Mathematics (STEM), concept maps, peer instruction methods, open inquiry methods, learning integrated with music, and learning using a computer simulation model.