Miracle-dz/UniFAR-FTUs huggingface dataset:
Nearly Unstable Processes: A Prediction Perspective

Prediction has long been a vibrant topic in modern probability and statistics. In addition to finding optimal forecast and model selection, it is argued in this paper that the prediction principle can also be used to analyze critical phenomena, in particular, stationary and unstable time series. Although the notion of nearly unstable models has become one of the important concepts in time series econometrics, its role from a prediction perspective is less developed. Based on moment bounds for the extreme-value (EV) and least squares (LS) estimates, asymptotic expressions for the mean squared prediction errors (MSPE) of the EV and LS predictors are obtained for a nearly unstable first-order autoregressive (AR(1)) model with positive error. These asymptotic expressions are further extended to a general class of nearly unstable models, thereby allowing one to understand to what degree such general models can be used to establish a link between stationary and unstable models from a prediction perspective. As applications, we illustrate the usefulness of these results in conducting finite sample approximations of the MSPE for near unit-root time series.
Calculation of Dose Gamma Ray Buildup Factor Up to Thickness of 20mfpUsing Taylor's Method

The dose gamma ray buildup factor for different materials (Al, Cu and Pb) up to 20mfp had been calculated using computer programs, which were constructed to calculate this factor for different materials using Taylor’s formula for point isotropic source . The programs had been designed to work with any atomic number and energy by adapting Lagrange interpolation method according to the studied factors (thickness of the shielding, energy of the gamma ray and atomic number of the shield (. Key words: Dose gamma ray for point isotropic source-Dose gamma ray buildup factor- Taylor’s formula-Lagrange interpolation method.
Pressured Chains: The role of Supply Chain Technology Utilisation

The institutional theory elucidates that businesses seek to provide a reasonable and relevant explanation for their behaviour because they are motivated by the need for social justification within institutional settings that shape their strategic directions and decisions. This study examined the supply chain performance implications of institutional pressures and supply chain technology among Ghanaian firms. The study employed the quantitative method and survey design. Data was sourced from 394 managers of small to large-scale firms operating in the Greater Accra Metropolis of Ghana. Data were analysed using Structural Equation Models (SEM). The study found that institutional pressures positively relate to supply chain performance. It was also discovered that supply chain technology utilisation (SCTU) mediates the relationship between Institutional pressures (INP) and supply chain performance (SCP). The finding shows the relative importance of INP and SCTU on the performance of supply chains of firms in Ghana. The study recommended that firms in Ghana and Africa must pay critical attention to supply chain technology to enhance their supply chain operations. The study provides practical implications for firms by highlighting the importance of institutional pressures and supply chain technology utilization in supply chain performance. This will provide firms with the insight to identify the most important institutional pressures that affect their supply chain technology utilization and performance. The study also encourages the use of technology in supply chain management. This can lead to more efficient and effective supply chains, which can help society by lowering prices and making more products available. The study is unique in its focus as it attempts to shift the discourse beyond how institutional pressures influence firms’ environmental and sustainability performance to how they impact supply chain performance.
Componentes del rendimiento y valor nutritivo de Brachiaria humidicola cv Chetumal a diferentes estrategias de pastoreo

The objective of this paperwas to study the effect of yield of Brachiaria humidicola cv Chetumal grass at different frequencies and intensities of grazing. The cutoff frequencies of 21 and 28 d and the intensities of 9-11 and 13-15 cm were evaluated, which were randomly distributed in a random block design with 2*2 factorial arrangement with three replicates. Management effects on dry matter accumulation were observed, with accumulation at lower frequency and light grazing intensity being greater. Forage production had a seasonal distribution of 66, 26 and 7% in the rainy season, north and dry seasons, respectively. The leaf ratio in harvested forage was 20, 30 and 86% for north, dry and rainy seasons, respectively. Reductions in dry matter digestibility were observed in the north and rainy seasons as the cut interval increased. The crude protein with severe grazing was 11, 10 and 17% higher in the north, dry and rainy times than with light. It is concluded that the highest forage production was obtained when harvesting at a light intensity of 13-15 cm, every 28 d and the highest protein content and digestibility was obtained when the forage was harvested at severe intensity every 21 d.
Length-weight relationships and reproductive biology of commercially important fishes from Ribb Reservoir, Ethiopia

It is important to understand the biological aspects of fish for fishing management. This study was conducted from February through October 2021. A total of 1,629 fishes were collected using different fishing gears. The length-weight relationship is a power curve for all fishes and showed a significant ( r 2 > 0.8). All fishes revealed a negative allometric growth pattern except Labeobarbus intermedius . Oreochromis niloticus (1.714 ± 0.009) was found in better condition than other fish species (analysis of variance [ANOVA], p < 0.05). The length at maturity was 24.0 cm and 25.4 cm total length (TL), 28.9 cm and 28.2 cm fork length, and 53.2 cm and 57.5 cm TL for females and males of O. niloticus , L. intermedius and Clarias gariepinus , respectively. Fecundity was ranged between 100–947 eggs/g with absolute fecundity (AF) of 468–3,832 eggs, 200–1,000 eggs/g with AF of 2,752–136,420 eggs, and 505–900 eggs/g with AF of 2,000–6,404 eggs for O. niloticus , C. gariepinus , and L. intermedius , respectively. Their respective mean fecundity was 1,490 ± 91, 23,330 ± 5,070, and 3,096 ± 273 eggs, respectively. Mean fecundity revealed a significant variation between size classes and species (ANOVA, p < 0.05). The fecundity length and fecundity-body weight relationships except ( O. niloticus ) of fishes were curvilinear while the gonad weight (GW)-fecundity relationship was linear for all fish species. The fecundity was moderately associated with increasing length than body weight, and GW for all fishes ( r 2 > 0.6). In conclusion, a tangible management setup is required to sustain the use of fish in the reservoir.
Perinatal Risk Factors in Children Diagnosed with Autism Spectrum Disorder in Dubai: A Case-Control Study

Introduction: Autism spectrum disorder (ASD) is a heterogeneous disorder characterized by deficits in social-emotional reciprocity and associated behavioral symptoms. The goal of this study was to examine perinatal risk factors for ASD and their correlates in a tertiary care hospital in Dubai, United Arab Emirates (UAE). Methods: We conducted a case-control study of 87 children diagnosed with ASD using the DSM-5 criteria, who were born between 1999 and 2014, and diagnosed between 2014 and 2016, and 134 age- and gender-matched control subjects. Data were collected from hospital medical records. Associations between ASD and maternal, birth, and neonatal risk factors were examined using logistic regression analysis. Results: Maternal fever was associated with ASD (p = 0.018), with 0% in the control group and 5% in the cases. Multivariate logistic regression analysis revealed a trend for an association between high birthweight (>4,000 g) and ASD (95% CI: 0.76–59.93, p = 0.086). Conclusion: The data affirmed the established gender difference of approximately four males to one female and supported previous findings associating ASD with prematurity. Larger representative studies are further required to explore risk factors for ASD in the UAE.
Development of diagnostic test instruments to reveal level student conception in kinematic and dynamics

The purpose of this research was to develop a diagnostic test instrument to reveal students' conceptions in kinematics and dynamics. The diagnostic test was developed based on the content indicator the concept of (1) displacement and distance, (2) instantaneous and average velocity, (3) zero and constant acceleration, (4) gravitational acceleration (5) Newton's first Law, (6) and Newton's third Law. The diagnostic test development model includes: Diagnostic test requirement analysis, formulating test-making objectives, developing tests, checking the validity of the content and the performance of reliability, and application of tests. The Content Validation Index (CVI) results in the category are highly relevant, with a value of 0.85. Three questions get negative Content Validation Ratio CVR) (-0.6), after revised distractors and clarify visual presentation; the CVR become 1 (highly relevant). This test was applied, obtained 16 valid test items, with Cronbach Alpha value of 0.80. It can conclude that diagnostic test can be used to reveal the level of students conception in kinematics and dynamics.
Application of the Euler Lagrange Formalism for Determining the Equation of Motion in the Case of Radial Fall into a Non-Rotating, Charged Black Hole

In this paper we set to accomplish two things: determine the equation of motion for an uncharged test probe falling radially into a charged, non-rotating black hole and determine the relationship between coordinate acceleration and coordinate speed. The paper is concerned only what happens outside the event horizon, since we are using only the external Reissner-Nordstrom equations in the derivations. What happens inside the event horizon (the presence of a wormhole connecting the black hole to a white hole) is outside the scope of this paper.
ANALYSIS OF THE MAIN DETERMINANTS OF THE SHADOW ECONOMY BASED ON SELECTED COUNTRIES OF CENTRAL ASIA

This article focuses on assessing the determinants of the shadow economy in Kazakhstan, Kyrgyzstan, and Uzbekistan from 2010 to 2020. Examining the experience of these countries reveals the full range of problems associated with the shadow economy and its impact on economic growth. One of the objectives of the article was to examine the causes of the shadow economy and highlight the highest-income but most vulnerable sectors of the economy. Three Central Asian countries were selected to determine the importance of some factors on the shadow economy in developing countries. To assess the importance of the factors, data for these countries were collected from www.data. worldbank.org and www.theglobaleconomy. com. Empirical research shows that more than 80% of the size of the shadow economy in these countries can be explained by factors such as the total number of employees, the tax rate as a percentage of commercial profits, GDP per capita and imports of goods and services as a percentage of GDP. At the same time, the correlation analysis proves that the increase and active participation of young people of working age reduces the volume of the shadow economy.
Segmentation of point clouds using smoothness constraints

For automatic processing of point clouds their segmentation is one of the most important processes. The methods based on curvature and other higher level derivatives often lead to over segmentation, which later needs a lot of manual editing. We present a method for segmentation of point clouds using smoothness constraint, which finds smoothly connected areas in point clouds. It uses only local surface normals and point connectivity which can be enforced using either k-nearest or fixed distance neighbours. The presented method requires a small number of intuitive parameters, which provide a tradeoff between underand over-segmentation. The application of the presented algorithm on industrial point clouds shows its effectiveness compared to curvature based approaches.
Broadband terahertz half-wave plate based on anisotropic polarization conversion metamaterials

We propose a half wave plate in the terahertz region to realize broadband linear polarization conversion in the reflection mode through anisotropic metamaterials. The structure of this design is composed of two pairs of patches in one unit cell that can rotate the polarization direction of a linearly polarized incident wave for an angle of 2β in a broadband frequency range. This work concentrates mainly on numerical simulations by using the standard finite difference time domain method. The efficiency of the half wave plate is higher than 50%, and PCR is higher than 85% in a broadband frequency range for cross polarization conversion. In the operating frequency band, three polarization conversion peaks can be found with the conversion efficiency nearly 100%. A more outstanding performance can be achieved by using low-loss substrate. The in-depth physical mechanism is revealed by further analysis. Besides, the expressions referring to theoretical decomposed electric field are deduced.
Moduli spaces of curves and enumerative geometry via topological recursion

The thesis considers several enumerative geometric problems concerning the topology of the moduli space of curves and their combinatorics. These enumerative geometric problems are analysed from different intertwined points of view and using different mathematical tools, including Hurwitz theory, Givental theory, cohomological field theories, integrable hierarchies, Fock spaces, quantum curves, and a relatively new powerful technique introduced by Chekhov, Eynard and Orantin known as topological recursion. These subjects lie in the interplay between enumerative algebraic geometry, differential geometry and mathematical physics.
Using geospatial data to identify land grabbing. Detecting spatial reconfigurations during the implementation of the Nacala Development Corridor in Mozambique with remote sensing and land conflicts databases

ABSTRACT The contemporary food system pushes agriculture to a globalized value-chain, affecting landscapes, resource access, and institutional arrangements. Institutions operating in Africa adopt development corridors to integrate multisector investments and induce export-driven primary sector, leading to massive land deals, also known as land-grabbing. Organizations struggle to monitor land deals accurately, lacking spatial precision and contextual information for affected communities. This research examines Mozambique's Nacala Corridor, using geospatial data as a tool to detect spatial (re)configurations due to exported-oriented policies and infrastructure. Data from land conflicts databases (Land Matrix and Environmental Justice) were analyzed with remote sensing Landsat and MODIS imagery using multiple indexes, an EVI time series, and the application of the LandTrendr algorithm. The results show that the temporal and spatial analysis of remote-sensing data is in line with the major political and economic dynamics of the region. Hotspots of land cover changes were detected in the same areas where land grabbing were reported; however, reported and detected land areas did not coincide. Temporal analysis showed that institutional changes played a greater role in triggering land use changes than infrastructure implementation. We conclude that land cover modifications, conflicts, and spatial development initiatives follows policies and institutional arrangements targeting international investments.
Interface roughening in irradiated oxide dispersion strengthened steels

Oxide Dispersion Strengthened steels are considered as promising candidates for nuclear applications as cladding tubes for GEN IV reactors. These materials are reinforced by a fine dispersion of nano-oxides whose semi-coherent flat interfaces constitute trapping sites for radiation-induced point defects. However, the sink strength of such interfaces may change under irradiation since the interfaces become damaged themselves. Therefore, the behavior of semi-coherent flat interfaces under irradiation is under concern. After ion irradiation up to 150 dPa at 500 °C, High Resolution Transmission Electron Microscopy images show that interfaces are no longer sharp but present an irregular mound morphology owing to the destabilization by the nuclear cascade collisions of incoming ions. Further, the kinetic roughening of the interfaces appears to increase with the irradiation dose. However, the low magnitude of the roughness suggests that the interfaces are remarkably stable under irradiation.
On finite expansion of a hole in a thin infinite plate

A complete solution for all values of applied pressure is obtained for the expansion of a hole of zero radius in an initially uniform infinite sheet. The analysis is compared with those of previous investigators and found to be simpler and/or more complete. It is shown that the results are applicable to the expansion of a finite hole in a uniform sheet and to theexpansion of a hole in a tapered sheet.
Nonlinear and Adaptive Intelligent Control Techniques for Quadrotor UAV – A Survey

Parametric uncertainties and coupled nonlinear dynamics are inherent in quadrotor configuration and infer adaptive nonlinear approaches to be used for flight control system. Numerous adaptive nonlinear and intelligent control techniques, which have been reported in the literature for designing quadrotor flight controller by various researchers, are investigated in this paper. As a priori, each conventional nonlinear control technique is discussed broadly and then its adaptive/observer based augmentation is conferred along with all possible variants. Among conventional nonlinear control approaches, feedback linearization, backstepping, sliding mode, and model predictive control, are studied. Intelligent control approaches incorporating fuzzy logic and neural networks are also discussed. In addition to adaption based parametric uncertainty handling, various other aspects of each control technique regarding stability, disturbance rejection, response time, asymptotic, exponential and finite time convergence etc., are discussed in sufficient depth. The contribution of this paper is the provision of detailed and in depth discussion on quadrotor nonlinear control approaches to the flight control designers.
The Use of STEM-Based Learning Activities to Promote Computational Thinking of Grade 5 Students

This study aimed to investigate the effects of STEM-based activities on grade 5 students’ science learning achievement, computational skills, and satisfaction with the learning experience. The study involved 30 grade 5 students in the Thai context, and data were collected through a learning management plan designed using STEM-based activities, a learning achievement test, a computational thinking test, and a satisfaction questionnaire. Mean scores, standard deviation, and a paired samples t-test were used to analyze the data. The results showed that STEM-based activities had a positive impact on grade 5 students’ learning achievement and computational thinking skills. Moreover, the students expressed a high level of satisfaction with the STEM-based activities, which provided an engaging and relevant learning experience. These findings contribute to the growing body of evidence supporting the effectiveness of STEM-based activities in promoting student achievement and satisfaction with the learning experience.
The scientific applications of big data in science of science

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Estimation and Testing in Panel Data with Cross-Section Dependence

This thesis makes a contribution the econometrics of panel data with cross-section dependence (CSD). It consists of five self-contained papers. The most popular approach to account for CSD is to attribute the co-movements of observed variables across entities to unobserved common factors and to estimate these factors via simple cross-section averages of the data. The chapters in this thesis investigate the properties of regression estimators that are based on this approach and suggest new tests that rely on cross-sectionaverages to capture the impact of latent common factors.Chapter two points out a problem with the Common Correlated Effects (CCE) estimator of Pesaran (2006) that appears in the empirically relevant case when the number of factors is strictly less than the number of observables used in their estimation. Specifically, the use of too many observables causes the second moment matrix of the estimated factors to become asymptotically singular, an issue that has not yet been appropriately accounted for. We show that the dominating method of proving the asymptotic properties of the CCE estimator breaks down in this case and suggest a more general method of proof.Chapter three develops PANICCA, an approach to panel unit root testing that combines the merits of the two most popular approaches for testing for a unit root in panel data with CSD. We take over the separate treatment of idiosyncratic and common components inherent in the PANIC framework which allows todetermine the source of nonstationarity specifically. In order to decompose the observed data into its two components, we use cross-section averages of all available variables, a simple, yet powerful approach with good small sample properties.Chapter four considers models where the impact of latent factors converges to zero as the number of individuals tends to infinity. These so-called weak factors constitute a setting for which the two dominating regression estimators for panel data with CSD are not explicitly conceived for. We investigate theasymptotic properties of these two estimators and set up minimal conditions for the factor strength under which asymptotic normality and consistency can be proven.Chapter five suggests a Hausman test statistic based on the difference between Pesaran’s (2006) CCE estimator and the OLS estimator. Under the null hypothesis of no cross-section dependence, this difference has a higher rate of convergence than the estimators themselves. As an immediate consequence, the test statistic diverges at a higher rate than the popular CD test of Pesaran (2004) when the data are crosssectionally correlated, thus leading to a test with higher power.Chapter six provides a simple and user-friendly way of measuring the contribution of different markets on developments in the fundamental price of an asset. We note that standard models for price discovery can be represented in the form of a common factor model and use a decomposition based on cross-section averages to separate idiosyncratic and common components of the observed price series.