Miracle-dz/UniFAR-FTUs huggingface dataset:
Predicción de dificultades estudiantiles mediante técnicas de minería de textos

Uno de los problemas a los que se enfrenta el docente universitario, se relaciona con la falta de retroalimentación por parte de los estudiantes, que le permita conocer las dificultades que ellos enfrentan a la hora de adquirir conocimientos nuevos en clase. Algunos esfuerzos de investigación se han realizado para identificar y clasificar los problemas de los estudiantes, con datos provenientes de las redes sociales, pero limitando los criterios de búsqueda y recuperación de los datos. El presente artículo pretende cubrir la brecha dejada por los trabajos anteriores, mediante la creación de una metodología para predecir las dificultades de los estudiantes universitarios, que utiliza técnicas de extracción de datos provenientes de la red social Twitter y que ha sido plasmada en un flujo de trabajo, que integra técnicas de Minería de Textos, Procesamiento de Lenguaje Natural y Aprendizaje Profundo, usando Algoritmos Supervisados y Redes Neuronales Recurrentes. Para probar la metodología propuesta, se construyó un modelo de clasificación, cuya evaluación es prometedora, pues se alcanzó una precisión y exactitud del 80%. Los resultados obtenidos garantizan la predicción de las dificultades estudiantiles, dotando al docente de una herramienta efectiva para identificar las áreas que demanden mayor atención y poder así brindar ayuda oportuna a los estudiantes que tienen dificultades en el aula.
Kerr black holes with synchronised hair: an analytic model and dynamical formation

East and Pretorius [1] have successfully evolved, using fully non-linear numerical simulations, the superradiant instability of the Kerr black hole (BH) triggered by a massive, complex vector field. Evolutions terminate in stationary states of a vector field condensate synchronised with a rotating BH horizon. We show these end points are fundamental states of Kerr BHs with synchronised Proca hair. Motivated by the “experimental data” from these simulations we suggest a universal (i.e. field-spin independent), analytic model for the subset of BHs with sychronised hair that possess a quasi-Kerr horizon, applicable in the weak hair regime. Comparing this model with fully non-linear numerical solutions of BHs with synchronised scalar or Proca hair, we show the model is accurate for hairy BHs that may emerge dynamically from superradiance, whose domain we identify.
Percepção da Governança Familiar em uma Pequena Empresa de Turismo Rodoviário

Este trabalho foi desenvolvido para melhor entender como governança familiar, um tema relativamente novo, se aplica a pequenas empresas familiares. Empresas familiares tem significativa importância na economia e no índice de empregabilidade. O problema que esse estudo buscou responder foi: como práticas de governança familiar influenciam pequenas empresas no setor de transportes. Para isso, uma entrevista em profundidade foi feita com o dono e gerente de uma pequena empresa de turismo rodoviário de Americana, São Paulo, Brasil. O estudo encontrou que a empresa em questão não adota mecanismos de governça, e muito dos relacionamentos depende da confiança dos membros da família controladora. A adoção de mecanismos de governança corporativa e familiar poderiam gerar resultados positivos para a empresa em questão e outras do setor.
Atomic force microscope local oxidation nanolithography of graphene

We demonstrate the local oxidation nanopatterning of graphene films by an atomic force microscope. The technique provides a method to form insulating trenches in graphene flakes and to fabricate nanodevices with sub-nanometer precision. We demonstrate fabrication of a 25-nm-wide nanoribbon and submicron size nanoring from a graphene flake. We also found that we can write either trenches or bumps on the graphene surface depending on the lithography conditions. We attribute the bumps to partial oxidation of the surface and incorporation of oxygen into the graphene lattice.
The Long-Period AM Herculis--like Cataclysmic Variable RXJ 051541+0104.6

We report the discovery of a new catacysmic variable system, RXJ051541+0104.6. The optical spectrum has a blue continuum with superposed H~I and He~I and II emission lines. The soft X-ray spectrum is well fit with a 50~eV black body. The X-ray and optical data are suggestive of an AM~Herculis system. The X-ray light curve shows extreme variability on timescales of seconds, and suggests an orbital period of order 8~hours, nearly twice that of the longest catalogued AM~Her period. When bright, the X-ray light curve breaks up into a series of discrete bursts, which may be due to accretion of dense blobs of material of about 10$^{17}$~gm mass.
Enhanced pair production of heavy Majorana neutrinos at the LHC

Towards experimental confirmations of the type-I seesaw mechanism, we explore a prospect of discovering the heavy Majorana right-handed neutrinos (RHNs) from a resonant production of a new massive gauge boson ($Z^{\prime}$) and its subsequent decay into a pair of RHNs ($Z^{\prime}\to NN$) at the future Large Hadron Collider (LHC). Recent simulation studies have shown that the discovery of the RHNs through this process is promising in the future. However, the current LHC data very severely constrains the production cross section of $Z^{\prime}$ boson into dilepton final states, $pp \to Z^{\prime}\to \ell^{+}\ell^{-} $ ($\ell=e$ or $\mu$). Extrapolating the current bound to the future, we find that a significant enhancement of the branching ratio ${\rm BR}(Z^{\prime}\to NN$) over ${\rm BR}(Z^{\prime}\to \ell^{+}\ell^{-}$) is necessary for the future discovery of RHNs. As a well-motivated simple extension of the Standard Model (SM) to incorporate the $Z^\prime$ boson and the type-I seesaw mechanism, we consider the minimal U(1)$_X$ model, which is a generalization of the well-known minimal $B-L$ model without extension of the particle content. We point out that this model can yield a significant enhancement up to ${\rm BR}(Z^{\prime}\to NN)/{\rm BR}(Z^{\prime}\to \ell^{+}\ell^{-}) \simeq 5$ (per generation). This is in sharp contrast with the minimal $B-L$ model, a benchmark model commonly used in simulation studies, which predicts ${\rm BR}(Z^{\prime}\to NN)/{\rm BR}(Z^{\prime}\to \ell^{+}\ell^{-}) \simeq 0.5$. With such an enhancement and a realistic model-parameter choice to reproduce the neutrino oscillation data, we conclude that the possibility of discovering RHNs in the future implies that the LHC experiments will soon discover the $Z^\prime$ boson.
Performance Comparison of Imputation Methods for Mixed Data Missing at Random with Small and Large Sample Data Set with Different Variability

One of the concerns in the field of statistics is the presence of missing data, which leads to bias in parameter estimation and inaccurate results. However, the multiple imputation procedure is a remedy for handling missing data. This study looked at the best multiple imputation methods used to handle mixed variable datasets with different sample sizes and variability along with different levels of missingness. The study employed the predictive mean matching, classification and regression trees, and the random forest imputation methods. For each dataset, the multiple regression parameter estimates for the complete datasets were compared to the multiple regression parameter estimates found with the imputed dataset. The results showed that the random forest imputation method was the best for mostly a sample of 500 irrespective of the variability. The classification and regression tree imputation methods worked best mostly on sample of 30 irrespective of the variability.
The center of mass energy of two colliding particles in the STU black holes

In this paper we consider collision of two particle near the STU black hole and calculate center of mass energy. In the case of uncharged black hole we find that the maximum energy obtained near the black hole horizon which similarly happen for charged black hole. We verify that the black hole charge may be decreased or increased the center of mass energy near the black hole horizon.
Physiochemical and Sensorial Properties of Burgers Produced from Nubian Goat Meat and Beef

Purpose: This study was aimed to evaluate sausage processed from different levels of goat meat replacement beef meat. Methodology: Beef top side cut and goat leg were purchased from local market and used according to A ( Beef 50 % ,goat meat 50 % ) , B( beef 25 % , goat meat 75 % ) , C ( goat meat 100 % ) and D ( Beef 100 % ) as control group, and to compare the goat meat sausages with the most common commercial sausages made with beef. Findings: The chemically, crude protein percentage was significantly different (p<0.05) in sausage treatments where higher in beef sausage, ash, and fat were also different increased with beef meat among sausage treatments, on the other hand moisture content increased with goat meat. Ultimate pH and cooking loss % of sausage treatments were significantly different (p <0.05). Total viable bacterial counts of sausage treatments were determined. Sensory attributes, including color, flavor, juiciness, tenderness, and overall acceptability among the different types of sausages prepared were no significantly differences (p > 0.05) Unique contribution to theory, practice and policy: Goat meat mainly from animals out of quality brands with low commercial value can be valorized when processed, giving the opportunity to increase its consumption and acceptability. In this study goat meat incorporated to the sausage ingredients with beef fat to evaluated the quality and flavor of sausage replacing beef meat. Sudanese Nubian goat meat useful for use in meat processing products with good characteristics and more acceptable for the final products. More researches for use goat meat in other meat products.
The circumstellar environment of high mass protostellar objects. III. Evidence of infall

The results are presented of a molecular line survey to search for the spectral signature of infall towards 77 850 µm continuum sources believed to be candidate high mass protostellar objects. Up to six different transitions, HCO + J = 1 → 0, J = 3 → 2a ndJ = 4 → 3, H2CO 212 − 111, N2H + J = 1 → 0a nd H 13 CO + J = 3 → 2, were observed towards each source. Towards the peak of the 850 µm emission, N2H + was typically strong, with a peak antenna temperature of ∼1.5 K, with a typical linewidth of ∼ 2k m s −1 . The good agreement between the velocity and velocity width of the N2H + and H 13 CO + emission suggests that both species are tracing similar material in the sources. With respect to the velocity of the N2H + , there is a statistically significant excess of blue asymmetric line profiles in both the HCO + J = 1 → 0a nd H 2CO transitions. This excess reaches levels similar to that seen towards samples of low mass protostars, and suggests that the material around these high mass sources is infalling. We identify 22 promising candidate infall sources which show at least one blue asymmetric line profile and no red asymmetric profiles. The infall velocity is estimated to be in the range of 0.1 km s −1 to 1 km s −1 with an implied mass accretion rate of between 2 × 10 −4 M� /yr and 10 −3 M� /yr.
Gravitational aspects of tachyon domain walls

This thesis derives and explores two solutions to the field equations of general rela­ tivity. These solutions are special cases of solutions already present in the literature. However, the present derivation is based on physical cirguments which provides a basis for discussing the solutions as cosmological objects, rather thsin simply as a class of solutions with certain symmetries. This derivation natursJly gives rise to the idea that the space-times indicated are generated by the passage of walls composed of gases of transcendant tachyons. After deriving the solutions, we explore the geodesies that these Wcdls generate. In general, they tend to focus the paths of particles moving through the walls. It is also found that the walls generate blue-shifts in observed photons emitted from sources that pass through the Weills. As applications of these solutions, numerical simulations demonstrate that a toy galaxy petssing through the second type of tachyon wall develops spiral structures which persist for several rota­ tions of the g£daxy, dissolve, and then reform throughout the lifetime of the galaxy. A number of open problems associated with these walls are discussed.
On the convergence of the proximal forward-backward splitting method with linesearches

In this paper we focus on the convergence analysis of the proximal forward-backward splitting method for solving nonsmooth optimization problems in Hilbert spaces when the objective function is the sum of two convex functions. Assuming that one of the functions is Fr\'echet differentiable and using two new linesearches, the weak convergence is established without any Lipschitz continuity assumption on the gradient. Furthermore, we obtain many complexity results of cost values at the iterates when the stepsizes are bounded below by a positive constant.
On variants of the CM2×2(C) M3×3(C) NCG model of elementary particles

We investigate restrictions to be imposed in the NCG C + M2 + M3 model to make it to fit with phenomenological data. Under strong condi- tions over the NCG field a leptophobic Zboson is got. Recent work (8) shows that naive application of Connes's scheme(7) to the CM2×2(C)�M3×3(C) algebra drives to a model of elementary particles which has not an easy phenomenological fit, nor a trivial method to remove anomalies. In this short letter, we point out that results can be best fitted if we take into account the difference between quark and leptonic sectors. In Connes' work (1), the bialgebra CM2×2(C),CM3×3(C) is rejected because we need to get the quark yukawa couplings of the standard model, and such condition is automatically achieved if we take the bialgebra to be CIH,CM3×3(C). But no restriction was really needed for the lepton sector. So our path of search can start fromCM2×2(C),CM3×3(C) and look for conditions restricting the action on quarks to be quaternionik. Indeed, this can be the case if we demand the fields to show some kind of "Independence between actions by C and by M2×2(C)" Plan of letter is as follows: First we look some justifications for shrinking the M2×2(C) action to beIH over the quarks. We develop the calculation in the bimodule formalism, where it is simpler to separate quark and leptons. Then unimodularity conditions are applied and we examine the resulting fields, then relating it to the phenomenological ones. Finally, we conclude with some comments about where to extend this toy model towards. Remember that a field A is a first order operator A = P a(D,a ' ) which is self-adjoint under the �-involution (see (1, 2, 9) for details). For models of type A = C(M) AF, i.e, an algebra of continuous functions times a finite matrix algebra, this operator decomposes in a term due to the AF and other coming from the one of continuous functions. Theinvolution acts as adjunction in the finite part and anti-adjuction in the continuous one.
Universal afterglow of supernovaless gamma-ray bursts

The well-sampled afterglows of gamma ray bursts (GRBs) not associated with a supernova (SN) explosion, can be scaled down to a simple dimensionless universal formula, which describes well their temporal behavior. Such SN-less GRBs include short hard bursts (SHBs) and long SN-less GRBs. The universal temporal behavior of their afterglows is that expected from a pulsar wind nebula powered by the rotational energy loss of the newly born pulsar.
Automatic Epileptic Seizure Detection Using PSO-Based Feature Selection and Multilevel Spectral Analysis for EEG Signals

Automatic epileptic seizure detection technologies for clinical diagnosis mainly rely on electroencephalogram (EEG) recordings, which are immensely useful tools for epileptic location and identification. Currently, traditional seizure detection methods based only on single-view features have great limitations for the typical dynamic and nonlinear EEG signals. An objective of this paper is to investigate the effect of multiview feature selection and multilevel spectral analysis methods on the identification of the EEG signals for seizure detection. Here, multiview features are extracted from time domain, frequency domain, and information theory to collect adequate information of EEG signals. And a feature selection algorithm based on particle swarm optimization (PSO) is proposed for automatic seizure detection. Moreover, due to the different frequency components of the EEG signals, they are divided into four kinds of brain waves for multilevel spectral analysis. The effect of these four rhythm waves on seizure detection is compared. Three well-known classifiers are employed to classify EEG signals concerning seizure or nonseizure events. The result shows that the average accuracy, specificity, and sensitivity of classification with the CHB-MIT database are 98.14%, 98.64%, and 96.79%, respectively. The application of the PSO-based feature selection method for automatic seizure detection improves accuracy by 5.99% with the SVM classifier. Compared with the state-of-the-art methods, the proposed method has superior competence with high performance for automatic seizure detection. It is further shown that the feature selection method is an indispensable step in seizure detection. With PSO-based feature selection and multilevel spectral analysis, the θ wave in the frequency range of 4-7 Hz shows better performance in the identification of EEG signals and is more suitable for the proposed method. The PSO-based feature selection algorithm for automatic seizure detection can be a useful assistant tool for clinical diagnosis.
Torsional Alfvén resonances as an efficient damping mechanism for non-radial oscillations in red giant stars

Stars are self-gravitating fluids in which pressure, buoyancy, rotation and magnetic fields provide the restoring forces for global modes of oscillation. Pressure and buoyancy energetically dominate, while rotation and magnetism are generally assumed to be weak perturbations and often ignored. However, observations of anomalously weak dipole mode amplitudes in red giant stars suggest that a substantial fraction of these are subject to an additional source of damping localised to their core region, with indirect evidence pointing to the role of a deeply buried magnetic field. It is also known that in many instances the gravity-mode character of affected modes is preserved, but so far no effective damping mechanism has been proposed that accommodates this aspect. Here we present such a mechanism, which damps the oscillations of stars harbouring magnetised cores via resonant interactions with standing Alfven modes of high harmonic index. The damping rates produced by this mechanism are quantitatively on par with those associated with turbulent convection, and in the range required to explain observations, for realistic stellar models and magnetic field strengths. Our results suggest that magnetic fields can provide an efficient means of damping stellar oscillations without needing to disrupt the internal structure of the modes, and lay the groundwork for an extension of the theory of global stellar oscillations that incorporates these effects.
A Financial Risk Early Warning of Listed Companies Based on PCA and BP Neural Network

Financial risk, as one of the most influential and destructive risks in business, will make enterprises unable to escape the fate of bankruptcy if not warned and prevented in time. In the paper, we conducted research on the financial risk early warning of listed companies. A total of 250 companies were randomly selected from the Chinese A-share market from 2019 to 2021. By building the 26 financial indicators of listed companies and constructing the PCA-BP neural network, we compared the financial risk early warning effects among PCA-BPNN, SVM, and Logistic. It is found that the financial data processed by PCA can better adapt to the financial risk early warning model. The PCA-BPNN model improved the prediction accuracy of the financial risk early warning, which has strong generalization ability for the prediction of financial risk. Research findings have certain reference significance for precise judgment on the financial risk of companies.
The Effect of Nutritional Supplements on Fat- Soluble Vitamins and Fatty acids in The Milk of Breastfeeding Mothers during the Period of Breastfeeding

The study included a group of breastfeeding mothers from Salah al-Din Governorate and the surrounding villages, and the nursing mothers were divided into two groups and the number of breastfeeding mothers in each group was 6 mothers, three mothers in the city and three mothers in the village, and they were given nutritional supplements for vitamins and fatty acids, both according to his group. Results for breastfeeding mothers' milk before and after giving them nutritional supplements, there are differences in the levels of vitamins and fatty acids. It was noticed that the level of vitamins in the milk after nursing mothers took the nutritional supplement differed, so it was retinol (242-268) μg / L for mothers in the city and (213-260). g / L for mothers in the village and β--carotene (320-367) μg / L for mothers in town and (315-361) μg / L for mothers in the village and α-tocopherol (182-279) g / L for mothers in town and (120-225) μg / L for mothers in the village and calciferol (309-382) μg / L for mothers in the city and (258-269) μg / L for mothers in the village. As for the omega group for breastfeeding mothers, the levels of fatty acids in their milk were after Breastfeeding mothers take a nutritional supplement only and Mega (3,6,9) all fatty acids in the milk of breastfeeding mothers increased, so it was for lauric acid (18.02-20.01) mg / L for mothers in the city and (18.02-20.11) mg / L for mothers in the village and for palmitic acid (18.07-24.25) mg / L for mothers in the city and (24.25-26.15) mg / L for mothers in the village and for oleic acid (14.09-29.93) mg / L for mothers in the city and (29.43-29.13) mg / L for mothers in the village and for linoleic acid (22.13-28.16) mg / L for mothers in the city and (22.11-22.14) mg / L for mothers in the village, and for linoleic acid (22.26-26.59) mg / L for mothers in the city and (26.15-26.54) mg / L for mothers in the village and for Arachidonic acid (12.94-18.15) mg / L for mothers in the city and (12.94-18.15) mg / L for mothers in the village, and this explains that breast milk is directly affected by the nutritional intake and nutritional supplements taken by breastfeeding mothers during the breastfeeding period
Further Developments of the Fringe-Imaging Skin Friction Technique

Various aspects and extensions of the Fringe-Imaging Skin Friction technique (FISF) have been explored through the use of several benchtop experiments and modeling. The technique has been extended to handle three-dimensional flow fields with mild shear gradients. The optical and imaging system has been refined and a PC-based application has been written that has made it possible to obtain high resolution skin friction field measurements in a reasonable period of time. The improved method was tested on a wingtip and compared with Navier-Stokes computations. Additionally, a general approach to interferogram-fringe spacing analysis has been developed that should have applications in other areas of interferometry. A detailed error analysis of the FISF technique is also included.
Stochastic Recurrences and their Applications to the Analysis of Partition-Valued Processes

The thesis consists of two parts. In the first part (Chapter 1) a new technique is developed for the asymptotic analysis of the moments of linear random recurrences, and some general results are presented for the absorption times of non-increasing Markov chains. In the second part (Chapters 2 and 3) we establish new results for two models where linear distributional recurrences occur: these are the stick-breaking partitions (Chapter 2) and exchangeable coalescents (Chapter 3).