Error Level Research Articles

Predicting financial distress in Latin American companies: A comparative analysis of logistic regression and random forest models

Latin America represents a growing financial market. The performance of its private sector corporations is critical, as inadequate performance and financial distress can lead to significant losses for many stakeholders. This study assesses the efficacy of Logistic Regression (LR) and Random Forest (RF) techniques in predicting corporate distress up to three years in advance. Additionally, we discuss relevant indicators and compare our findings in two different scenarios (pre versus pandemic period). The results indicate that RF outperforms LR in terms of predictive power and error levels. The most effective predictors remained consistent over the 20-year period but varied between the two models. Importantly, the performance levels remained unaffected by the COVID-19 pandemic.

A new recursive method based on datasheet information to calculate the double diode model parameters of commercially available photovoltaic modules

In this study, a new method is introduced to compute the double-diode model parameters of commercially available photovoltaic modules. The new method has been based solely on datasheet-supplied electrical data. The new method offers two novelties. First, the dark reverse saturation currents are calculated analytically. Second, the parameters of the double-diode model are calculated by a new recursive procedure using tuning parameters. The validity of the new method is tested for twenty commercially photovoltaic modules with different technologies via the normalized root mean square error tool by comparing the datasheet current-voltage curves with simulated curves. In addition, the proposed method is compared with other methods at different operating conditions and also tested in the field under actual operating conditions using the root mean square error tool. It was founded that the new method calculates the parameters of the double diode model and simulates the current-voltage curves of commercially photovoltaic modules under various operating conditions with a high accuracy. Moreover, the new method is also very competitive with the selected methods and even achieves better simulation accuracy with a very low error level. The obtained results show that the new method is highly accurate, practical, and simple for all photovoltaic users.

Does media coverage of firms' environment, social, and governance (ESG) incidents affect analyst coverage and forecasts? A risk perspective

We examine whether and how media coverage of firms' environment, social, and governance (ESG) incidents is associated with analyst coverage and forecasts. We propound that the risks of firms could either increase or decrease as a result of media-covered ESG incidents, depending on the firms' actions on the media coverage, and thus its impact on analyst coverage and forecasts would vary. Based on a sample of U.S. listed companies, we find evidence that the level of analyst coverage is negatively associated with a firm's ESG incidents covered by the media. This association is more pronounced for firms with more intense industrial product market competition, more severe ESG scandals, or coverage by less sophisticated analysts. We also find that the firms' ESG incidents covered by the media would lead to higher levels of forecast error and dispersion. Our mediation analysis further reveals that business risk and information risk tend to be higher for firms covered by the media for having been involved in ESG incidents, thereby explaining why the analysts' coverage and forecasts for these firms are adversely affected. Overall, our results highlight the importance of curbing corporate social irresponsibility and improving analyst performance in forecasting.

Application of Transition Finite Elements in hpq-Adaptive Modeling and Analysis of Machine Elements

This paper concerns modeling and analysis of machine elements using the adaptive finite element method. The adaptation used is of hpq type, which means that the finite element dimension h and element transverse q and longitudinal p approximation order may be different in each element. These parameters are determined automatically by the program so as to obtain modelling and approximation error levels not higher than the assumed admissible level of the errors. The presented paper focuses on the use of transition elements between basic elements corresponding to the three-dimensional theory of elasticity and the first-order shell model. Three applied transition elements differ in their assumptions regarding the continuity of the displacement, strain and stress fields between the basic models. The effectiveness of the application of transition elements was assessed in terms of: removal of the internal boundary layer at the boundary between the models and convergence of adaptive solutions taking into account these models.

Analisis dan Simulasi Efisiensi Kinerja Sepic Konverter Berbasis Kontroler Konvensional

The technology of components and electronic hardware has evolved to be able to produce a DC/DC current system for power, which is achieved by converting the DC power to higher or lower voltage. This DC voltage variable is commonly called the DC-DC Converter. This final task aims to find out the performance of the DC-DC Sepic Converter series design. The simulated testing of the system using SIMULINK/MATLAB software is subsequently obtained from the data analysis of the theoretical output voltage data and the monitoring of measurements that can be analyzed to determine the error level as well as the level of efficiency of the design of the sepic converter. The test was conducted by setting a constant input voltage of 12 V, a frequency of 50 kHz, with a duty cycle variation of 5% to 65% and a given load of 20 Ω. The result of the design of the Sepic Converter at the time of open loop mode with the value of duty Cycle of 5% produces a minimum voltage that is 0,38 V. Subsequently, when given the duty cicle value of 65%, the maximum voltage is 21,22 V error with the highest error rate of 1 V obtained at the 13th data trial. The average error value is 0,642 V and the standard deviation value is 0,453 V, the greatest efficiency point is 78,50% at the moment of the cycle duty value of 65. While the results of the testing of the Set of Sepic Konverters at the close loop mode, the input tension is given constantly 12 V. The configuration for the parameter value of PI is also constant, namely at the set point of 22,22 V, it is 21,97 V with an error difference 0,25 V.

Validity and Reliability of the Lower Extremity Motor Coordination Test (LEMOCOT) in Patients with Multiple Sclerosis

The validity and reliability of the Lower Extremity Motor Coordination Test (LEMOCOT) were assessed in patients with multiple sclerosis (MS). The study involved 60 participants diagnosed with MS (mean age: 48.13 years, range: 24–80 years). Intra-rater reliability was assessed within-day (n = 12), and inter-rater reliability was assessed within-day (n = 45) and between-days (n = 22). For known-groups validity, test scores were compared between participants of different sexes; for convergent validity, test scores were correlated with age, the Five-Repetition Sit-to-Stand test (FSTS), the Berg Balance Scale (BBS), the Lower Extremity Functional Scale (LEFS), and the Expanded Disability Status Scale (EDSS). To test the discriminant validity, the LEMOCOT test scores were correlated with the Mini-Mental State Evaluation (MMSE) and compared according to social history (living alone or not). The LEMOCOT test was tested under three different conditions and found to be very reliable (intraclass correlation coefficient, ICC2,1 > 0.94) with an acceptable error level (standard error of the measurement, SEM, between 1.39 and 3.47 targets and 95% minimum detectable change; MDC95%, between 3.84 and 9.58 targets). Convergent validity was verified, as the LEMOCOT registered very strong correlations with the FSTS test (r = −0.851) and the BBS scale (r = 0.815), a strong correlation with the LEFS scale (r = 0.78), a moderate correlation with the EDSS scale (r = −0.634), all highly significant (p < 0.001), and a weak correlation with age (r = −0.332, p < 0.01). Discriminant validity was also confirmed, as the LEMOCOT demonstrated a weak correlation with the MMSE scale (r = 0.365, p = 0.017) and no differences relative to living environment or sex. The LEMOCOT demonstrated excellent reliability and validity for patients with MS.

Impact of the COVID-19 pandemic on acute ischemic stroke medical care: a prospective study

INTRODUCTION: Acute ischemic stroke (AIS) is not uncommon in patients with novel coronavirus infection. During the COVID-19 pandemic, an increase of the frequency of adverse clinical and functional outcomes of AIS was noted.OBJECTIVE: The recent study was to evaluate the impact of the COVID-19 pandemic on the clinical and diagnostic characteristics of patients with AIS, as well as on the results of various types of treatment.MATERIALS AND METHODS: The prospective study included 460 patients with AIS after systemic or selective thrombolysis, thromboextraction and combination of thromboextraction with thrombolysis and stenting, hospitalized in 2019–2022: 55 patients in 2019, and in 2020–2022 — 405 patients. All patients were clinically evaluated using NIHSS and Rankin scales. Instrumental data included: assessment of computed tomography (CT) lesion size, extracranial and transcranial Duplex ultrasound (DUS) and computed angiography. Patients who received invasive treatment (thromboextraction, including in combination with thrombolysis or stenting) underwent cerebral angiography (CA). The characteristics of cerebral hemodynamics before and after the use of various types of treatment, clinical and functional outcomes were subject for comparison.Statistics: The statistical software Statistica 12.0, SPSS Statistics 17.0 were used. Normality of distribution was assessed using the Shapiro–Wilks test. Comparison of groups based on quantitative parameters was carried out using the Mann–Whitney U test. When testing statistical hypotheses, the acceptable level of error of the first type was considered to be a value not exceeding 0.05. To assess the correlation between parameters, the Spearman method was used.RESULTS: During the pandemic of COVID-19, patients with AIS were younger, had lower percentage of comorbidities and a higher NIHSS score. A significantly lower rate of favorable clinical and functional outcomes was obtained during the pandemic compared to the period before the pandemic, including after the use of invasive treatment methods: only 47% of patients had clinical improvement during the pandemic, while in 2019 the proportion of favorable outcomes was 64% (p=0.003). There was an increase in the share of pulmonary embolism and pneumonia in the structure of mortality from AIS during the pandemic (25% in the period before the pandemic vs 38% during the pandemic). Duplex ultrasound of cerebral arteries demonstrated high comparability with angiography data (correlation coefficient with invasive methods 0.84).DISCUSSION: According to the literature data, strokes are not uncommon in patients with COVID-19, especially in those with severe disease and risk factors. The authors consider thrombosis and/or thromboembolism of cerebral arteries to be possible ways of cerebral ischemia. According to Russian scientists, from the beginning of the pandemic, a significant increase in the incidence of ischemic stroke of varying severity was noted. The statistical pattern we identified confirms the data from literature sources that when infected with the SARS-CoV-2 virus, the brain and cerebral arteries are target organs. It is significant for clinical practice that we have evaluated the clinical and instrumental characteristics of these lesions in relatively homogeneous gender, age and clinical groups.CONCLUSION: The incidence of favorable clinical and functional outcomes during the pandemic was significantly lower compared to the pre-pandemic period. Complete and partial restoration of blood flow, as well as a decrease in the ischemic focus, were significantly more common before the pandemic. The effectiveness of invasive methods of cerebral revascularization during the pandemic were also lower. Duplex ultrasound serves as a reliable method not only for primary diagnosis, but also for dynamic monitoring. Initial changes in hemodynamics in patients with AIS before and during the pandemic did not differ significantly and were represented by hypoperfusion with a decrease in peripheral resistance. In 2020–2022 after treatment, hypoperfusion was observed significantly more often, which can be considered as one of the reasons for the less favorable clinical and functional outcomes obtained during the pandemic.

The accuracy of length measurements made using imaging SONAR is inversely proportional to the beamwidth

Abstract Multibeam imaging SONARs have been used for a range of measurement applications, such as measurements of fish lengths. This study aimed to quantify the accuracy of imaging SONAR systems, that varied in frequency and beam geometry, to measure the length of synthetic targets positioned perpendicularly. Blueprint Oculus imaging SONAR systems, with four different (centre) frequencies (750 kHz, 1.2 MHz, 2.1 MHz and 3 MHz), were used to measure the length of three targets of nominal lengths: 10 cm, 20 cm and at ranges between 1 and 15.5 m. The effect of beam geometry on measurement error was then examined using regression analysis. This study found that there was an overestimation of the actual length of the target for all measurements that was inversely proportional to the horizontal beamwidth. The measurement error can be reduced by normalising for beamwidth. However, the variation of measurements (i.e. the precision) was found to also increase with range, which was attributed to the increasing beam separation. It is important that the effect of beamwidth on the accuracy of target length measurements, by imaging SONARs is acknowledged in future studies. One approach to mitigating this problem, is to limit the range at which length measurements are made to a beamwidth that produces an estimated level of error that is acceptable for that study.

On the Performance of Some Estimation Methods in Models with Heteroscedasticity and Autocorrelated Disturbances (A Monte-Carlo Approach)

The proliferation of panel data studies has been greatly motivated by the availability of data and capacity for modelling the complexity of human behaviour than a single cross-section or time series data and these led to the rise of challenging methodologies for estimating the data set. It is pertinent that, in practice, panel data are bound to exhibit autocorrelation or heteroscedasticity or both. In view of the fact that the presence of heteroscedasticity and autocorrelated errors in panel data models biases the standard errors and leads to less efficient results. This study deemed it fit to search for estimator that can handle the presence of these twin problems when they co- exists in panel data. Therefore, robust inference in the presence of these problems needs to be simultaneously addressed. The Monte-Carlo simulation method was designed to investigate the finite sample properties of five estimation methods: Between Estimator (BE), Feasible Generalized Least Square (FGLS), Maximum Estimator (ME) and Modified Maximum Estimator (MME), including a new Proposed Estimator (PE) in the simulated data infected with heteroscedasticity and autocorrelated errors. The results of the root mean square error and absolute bias criteria, revealed that Proposed Estimator in the presence of these problems is asymptotically more efficient and consistent than other estimators in the class of the estimators in the study. This is experienced in all combinatorial level of autocorrelated errors in remainder error and fixed heteroscedastic individual effects. For this reason, PE has better performance among other estimators.

Corneal Characteristics of Myopic Malay School Children and Their Association with Axial Length.

Corneal characteristics are unique to each eye and can vary among different levels of refractive errors. However, minimal data are available in the literature on corneal characteristics in myopic Malay school children including the difference between the low myopic group and the moderate myopic group. Therefore, this study aims to determine the corneal characteristics of myopic Malay school children and their associations with axial length. A total of eighty-four data samples were extracted from forty-two myopic Malay school children. Measurements of the central corneal thickness (CCT), corneal curvature, corneal diameter, and axial length were measured using Lenstar LS900, a non-contact optical biometer. Data were later stratified by the spherical equivalent refraction (SER) into a low myopic group and a moderate myopic group, and paired t-test were employed to determine the differences in the corneal characteristics between these two groups. Univariate and multivariate linear regressions were performed to identify factors that are significantly associated with axial length. There was no significant difference in the CCT, corneal curvature and corneal diameter between the low myopic group and the moderate myopic group (t82=0.015, P=0.99), (t82=-0.802, P=0.43) and (t82=-0.575, P=0.57), respectively. Pearson univariate correlation analysis found that axial length significantly correlated with corneal curvature (r=-0.765, P<0.001) and corneal diameter (r=0.614, P<0.001) but no significant correlation found with CCT (r=0.046, P=0.68). Multiple regression analysis showed that axial length was significantly associated with a flatter corneal curvature (P<0.001), older age (P<0.001) and larger corneal diameter (P=0.02). This study reported the corneal characteristics in myopic Malay school children and its associations with axial length. Results of this study can serve as a reference value for the myopic Malay schoolchild population.

Hearables: In-Ear Multimodal Data Fusion for Robust Heart Rate Estimation

Hearables: In-Ear Multimodal Data Fusion for Robust Heart Rate Estimation

Adapting to organizational change in a public sector high-reliability context: the role of negative affect and normative commitment to change

Abstract This study aims to investigate the impact of organizational change in a public sector high-reliability context. Drawing on conservation of resources theory, our theoretical model posits that change can be stressful and cause negative affective reactions toward the change, which undermine adjustment and post-change functioning. A quantitative case study was carried out on a Dutch air force squadron undergoing a significant organizational change, including the collection of three waves of survey data from squadron members. The data underwent analysis through a process of moderated mediation. Consistently with the theoretically derived hypotheses, results show that negative affect toward the change predicted important adjustment indicators, that is, higher levels of work role overload and work errors. Furthermore, we found that the detrimental effects of negative affect were mitigated by the level of normative commitment to change, that is, the felt obligation to provide support for the change. Overall, the study’s intended contribution lies in its detailed examination of change dynamics in the specific context of public high-reliability organizations and its potential to inform theory and practice in that area.

Analisis Peramalan dalam Menentukan Perencanaan Persediaan pada Toko Seragam Sekolah Hermul Jaya

Forecasting is an estimation of future events based on systematically compiled past data using certain methods. Forecasting is necessary as a basis for planning, therefore an appropriate forecasting method is needed to see a lower level of error so that inventory planning can be optimal and efficient. This study aims to find a more suitable method to be used at Hermul Jaya Clothing Store to determine the predicted amount of stock in the store. This research uses a descriptive quantitative approach and POM QM application to calculate the inventory forecast of uniform stores based on two indicators, namely Moving Average, Weighted Moving Average and Expponential Smoothing. From the results of this study, the stock inventory at Hermul Jaya Uniform Store is not yet effective because stock purchases or inventory are made without prior planning or it can be said that this store does not use forecasting methods

Retraction: miR-655 suppresses epithelial-to-mesenchymal transition by targeting Prrx1 in triple-negative breast cancer.

Zhi-Dong Lv, Bin Kong, Xiang-Ping Liu, Li-Ying Jin, Qian Dong, Fu-Nian Li, Hai-Bo Wang, miR-655 suppresses epithelial-to-mesenchymal transition by targeting Prrx1 in triple-negative breast cancer. Journal of Cellular and Molecular Medicine, 20: 864-873. https://doi.org/10.1111/jcmm.12770 The above article, published online on 28 January 2016 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor-in-Chief, Stefan Constantinescu, The Foundation for Cellular and Molecular Medicine, and John Wiley and Sons Ltd. In 2022, the authors asked to retract the article as they found that some images were mistakenly duplicated from their previously published papers. Subsequently, an investigation into concerns raised by a third party revealed inappropriate duplications and manipulation of images between this (Figures2B,D, 3A, 5B, 6C,D and 7B) and five other articles (with the same first or corresponding author) that were published previously or in the same year in a different scientific context. Due to the number and the level of errors identified in the published figures, the editors consider the conclusions of this manuscript substantially compromised. Although the authors initially asked for the retraction, they did not agree to the retraction wording.

Retraction: Silencing of Prrx1b suppresses cellular proliferation, migration, invasion and epithelial-mesenchymal transition in triple-negative breast cancer.

Zhi-Dong Lv, Zhao-Chuan Yang, Xiang-Ping Liu, Li-Ying Jin, Qian Dong, Hui-Li Qu, Fu-Nian Li, Bin Kong, Jiao Sun, Jiao-Jiao Zhao, Hai-Bo Wang, Silencing of Prrx1b suppresses cellular proliferation, migration, invasion and epithelial-mesenchymal transition in triple-negative breast cancer. Journal of Cellular and Molecular Medicine, 20: 1640-1650. https://doi.org/10.1111/jcmm.12856 The above article, published online on 29 March 2016 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor-in-Chief, Stefan Constantinescu, The Foundation for Cellular and Molecular Medicine and John Wiley and Sons Ltd. In 2022, the authors asked to retract the article as they found that some images were mistakenly duplicated from their previously published papers. Subsequently, an investigation into concerns raised by a third party, revealed inappropriate duplications of image panels within the article (Figures2A,B and 4D) as well as between this (Figure1B) and three other articles (with the same first or corresponding author) that were published previously in a different scientific context. Due to the number and the level of errors identified in the published figures, the editors consider the conclusions of this manuscript substantially compromised. Although the authors initially asked for the retraction, they did not agree to the retraction wording.

Pengaruh Pembelajaran TGT Menggunakan Kartu Permainan Luck and Ability Terhadap Motivasi Belajar Siswa SMP pada Materi Statistik

This research aims to determine the effect of mathematics learning using the TGT (Team Games Tournament) learning model assisted by luck and ability game cards on students' learning motivation in statistics material. The research method used is pre-experimental design with a one-group pretest-posttest design and uses a quantitative research approach. The subject of this research was class VIII A of Al-Furqon Middle School. The research instruments used were pre-questionnaires and post-questionnaires as well as test results as supporting data. The instrument is a questionnaire given twice (pre-questionnaire and post-questionnaire) which contains statements to measure students' learning motivation before and after implementing the TGT (Team Games Tournament) learning model. Apart from questionnaires, there are test instruments to support learning motivation data. The data analysis technique used is hypothesis testing. However, before carrying out a hypothesis test, the data obtained must first be tested for normality. Based on the calculation of the paired sample t test, it shows that the significance value is 0.000. The significance value shows 0.000 &lt; 0.05 error level, so it can be concluded that Ha is accepted. Acceptance of this Ha means that there is an influence of TGT learning using luck and ability game cards on junior high school students' learning motivation in statistical material.

Image Forgery Detection using ResNet50

Abstract: Image forgery detection is crucial in ensuring the integrity of digital media. In this study, we propose a method for detecting image tampering using Error Level Analysis (ELA) and Convolutional Neural Networks (CNNs) with a ResNet50 architecture. Leveraging the CASIA 2.0 Image Tampering Detection Dataset, which consists of authentic (Au) and tampered (Tp) images, along with metadata and annotations provided in the CASIA 2 Ground truth dataset, we develop and evaluate our model. The dataset comprises 7492 authentic images, 5125 tampered images, and 5123 files of ground truth information. ELA transformations highlight compression discrepancies, aiding in the identification of tampered regions. Our ResNet50-based CNN model, augmented with Global Average Pooling, Dense layers, and Dropout regularization, is trained using Adam optimization and binary cross-entropy loss with early stopping. Evaluation metrics, including training and validation loss/accuracy curves and confusion matrices, are used to assess model performance. The trained model is saved for future use and tested on new images to demonstrate its classification capabilities. Our approach achieves a significant level of accuracy in distinguishing between authentic and tampered images, underscoring its potential for practical image forgery detection applications and contributing to advancements in digital media forensics

Impact of Traffic Flow Rate on the Accuracy of Short-Term Prediction of Origin-Destination Matrix in Urban Transportation Networks

Information about spatial distribution (OD flows) is a key element in traffic management systems in urban transport networks that enables efficient traffic control and decisions to redirect traffic to less congested sections of the network in emergencies. With the development of modern techniques of remote sensing, more and more advanced methods are used to measure traffic and determine OD flows. However, they may produce results with different levels of errors caused by various factors. The article examines the impact of traffic volume and its variability on the error values of short-term prediction of the OD matrix in the urban network. The OD flows were determined using a deep learning network based on data obtained from video remote sensing devices. These data were recorded at earlier intervals concerning the forecasting time. The extent to which there is a correlation between the size of OD flows and the prediction error was examined. The most frequently used measure of prediction accuracy, i.e., MAPE (mean absolute percentage error), was considered. The analysis carried out made it possible to determine the ranges of traffic flow rate for which the MAPE stabilizes at the level of approximately 6%. A set of video remote sensing devices was used to collect spatiotemporal data. They were located at the entrances and exits from the study area on important roads of a medium-sized city in Poland. The conclusions obtained may be helpful in further research on improving methods to determine OD matrices and estimate their reliability. This, in turn, involves the development of more precise methods that allow for reliable traffic forecasting and improve the efficiency of traffic management in urban areas.

Impacts of temporal resolution of atmospheric de-aliasing products on gravity field estimation

SUMMARY Despite the increasing accuracies of GRACE (Gravity Recovery and Climate Experiment)/GRACE-FO (GRACE Follow-On) gravity field models through worldwide endeavours, the temporal aliasing effect caused by the imperfect background models used in gravity field modelling is still a crucial factor that degrades the quality of gravity field solutions. Since the important role of temporal resolution of atmospheric de-aliasing models, this paper specifically investigates the influence of temporal resolution on gravity field modelling from the perspectives of frequency, spectral and spatial domains. To this end, we introduced the gravitational acceleration and geoid height derived from the static gravity field GOCO06s in the inner integral. The introduction of the static gravity field has a comparable impact on LRI (Laser Ranging Interferometers) range-rate residuals as the accuracy of the LRI range-rate data, despite its magnitude of being less than 0.1 mm in the spatial domain. This finding also highlights the significance of error level in existing de-aliasing products as a crucial factor that restricts the current accuracy of gravity field solutions. Further analyses show that increasing the temporal resolution from 3 to 1 hr has an insignificant impact on the gravity solutions in both the frequency and spectral domains, which is also smaller than that caused by using different atmospheric data sets. However, in the spatial domain, LRI range-rate residuals can be effectively mitigated in certain regions of the Southern Hemisphere at mid- and high-latitudes by increasing the temporal resolution. Particularly, the discrepancies of mass change estimates brought about by enhancing temporal resolution have distinct characteristics, especially in the Congo River and the Amazon River Basins. The mass changes in terms of equivalent water height derived by using P4M6 filtering show that the maximum root mean square value of spatial differences caused by improving the temporal resolution of the atmospheric de-aliasing models can reach ∼13.4 mm in the subregion of the Congo River Basin. However, using different atmospheric data sets can lead to a maximum difference of ∼16.5 mm. For the Amazon River Basin, the corresponding maximum discrepancy is ∼18.1 mm, and that caused by improving temporal resolution is ∼9.4 mm. We further divide the Congo River Basin into several subregions using a lat-lon regular grid with a spatial resolution of 3°. The subsequent time-series results of mass changes reveal that the maximum contribution of temporal resolution and changes in the atmospheric data sets can reach 11.09 and 21.24 per cent, respectively. This suggests that it is necessary to consider the temporal resolution of de-aliasing products when studying mass changes at a regional scale.

MODELING OF THE ELECTRONIC AND ELASTIC PROPERTIES OF THE Y&lt;sub&gt;3&lt;/sub&gt;Al&lt;sub&gt;5&lt;/sub&gt;O&lt;sub&gt;12&lt;/sub&gt; CRYSTAL

In this scientific work, we conducted a comprehensive study of yttrium aluminum garnet using computer modeling methods. Our efforts are focused on the precise analysis of elastic properties, the development of equations of state, as well as a detailed study of crystal and band structures. We conducted a detailed study of the mechanical parameters of the material, such as the modulus of elasticity and the Poisson's ratio, using modern computational methods. Virtual modeling methods allow us to study in detail the mechanical characteristics of the material. The main focus is on the creation and verification of computer models that accurately reflect the elastic properties of the crystal. The values obtained using various hybrid functionals were compared with experimental data. Virtual models allowed not only to study in detail the mechanical characteristics of the material, but also provided results that are significantly close to real experimental data. Comparisons were carried out according to the following parameters: cell parameters, band gap energy, effective charges of crystal atoms, equations of state and elastic properties. Also, the error levels relative to the experimental data are determined. We present the results of the analysis of the crystal structure of yttrium aluminum garnet achieved using various exchange-correlation hybrid functionals such as B3PW, B3LYP, HSE06, PBE. This aspect of the study includes the analysis of the crystal lattice parameters, the distribution of atoms in the crystal and the band structure, which is important for a complete understanding of the properties of the material.