Miracle-dz/UniFAR-FTUs huggingface dataset:
Quantum theory for superradiance

In order to study the cooperative emission of radiation from an extended system of $N$ two-level atoms, we use the master-equation approach within the Born and Markov approximations. All the properties of the emission of radiation can be deduced from the diagonalization of the coupling matrix $\ensuremath{\Gamma}$, where an element ${\ensuremath{\Gamma}}_{\mathrm{jk}}$ gives the coupling between the atoms labeled $j$ and $k$ via the electromagnetic field. We choose a pencil-shaped volume and study analytically the coupling matrix in the limit for small and large Fresnel numbers. For Fresnel numbers of order unity numerical methods are used. Thus we prove that, for the pencil-shaped geometry, any elaborated model must take into account the interaction of the atoms with the infinity of electromagnetic field modes lying inside two small solid angles about the axis of the largest linear dimension, which we label the $z$ axis. In other words, the intensity of radiation emitted by any atom of the system depends on its position with respect to the others and this "propagation effect" cannot be neglected when interpreting superradiance experiments. For small Fresnel numbers the $z$ dependence predominates, in the opposite case the ($x, y$) dependence does, while for Fresnel numbers of order unity the dependence of all three components must be taken into account. Preliminary calculations are given for which only the $z$ dependence is considered; for Fresnel numbers of magnitude of order unity or smaller, the effect of propagation along the $z$ axis displays large delays for the appearance of superradiance with respect to the time at which the superradiant pulse is maximum when the "propagation effects" are neglected (one-mode model).
Dimensionality effects on the strongly interacting Bose-Einstein condensate with three-body interactions

Using the density-functional theory, the Ginzburg Pitaevskii Gross (GPG) equation for Bose-Einstein (BE) condensate, confined in a magnetic trap, is modified to include contribution from three-body collisions in the strongly interacting regime a>>l, 'a' is the scattering length and 'l' being the characteristic low energy length scale. This generalized GPG equation has been solved numerically using the analytically derived Thomas-Fermi order parameter, which also includes three-body interactions. The order parameter, chemical potential, extent of correlation and other ground state properties are computed when the aspect ratio, λ, is varied from1.0 to 0.05 (λ represents the anisotropy of the magnetic trap). As λ is varied from 1.0 to 0.05, the condensate shape changes from isotropic three-dimensional (3-D) to highly anisotropic quasi one-dimensional (1-D). The stability of the BE condensate increases with decrease in λ, which is also borne out by the behavior of chemical potential and the total energy per particle, as there is a decrease of about four times for a=5000 a0 as well as for a=7000 a0, 'a0' being the Bohr radius. The extent of correlations, however, increases by more than five folds, showing that quasi 1-D BE condensate is highly correlated. Both two- and three-body interaction energies show a decrease with decrease in λ: three-body interaction energy staying below two-body interaction energy for a=5000 a0 while for a=7000 a0, a cross-over occurs between the two at λ ~ 0.35. As one goes from 3-D to quasi 1-D, the percentage difference for various physical quantities, computed between only two-body interactions and when both two- and three-body interactions are considered, shows a decrease, suggesting that the effect of three-body collisions become increasingly less significant in agreement with the recent study.
WHEN ARE TWO STEP ESTIMATORS EFFICIENT

Kruskal's theorem is used to provide simple and elegant alternative derivations of the efficiency of some two step estimators (2SE) for models containing anticipated and unanticipated variables. Several new results are established: 2SE is not efficient for a structural equation with current and lagged values of both anticipated and unanticipated variables; 2SE is always efficient for the parameter associated with the current unanticipated variable, and for the parameter associated with the lagged unanticipated variable if there is no lagged dependent variable in the expectations equation; the inclusion of additional regressors in the structural equation and contemporaneous correlation of the structural and expectations errors can both be analysed in a straightforward manner; the single-equation generalized least squares estimator can be as efficient as the systems maximum likelihood estimator.
“Student preference towards the utilization of Edmodo as a learning platform to develop responsible learning environments" study

Teachers can simply establish and administer online learning communities using Edmodo, and students may connect and collaborate with their peers and teachers whenever they want, from any location. A safe and cost-free educational learning network, Edmodo. To promote participation and responsible learning, this study sought to ascertain how much students preferred to utilize the academic social networking site Edmodo. The goal of this essay is to determine whether using Edmodo as a teaching tool is appropriate that more teachers should employ to support a student-centered, technologically-based learning environment where students participate and put their ideas about responsible learning into practice. The study was carried out in a private institution in Banjarharjo, Central Java. Only 320 of the 280 degree-seeking participants were actually used in the analysis. This study used a quantitative methodology,and a survey with research-designed questions was utilized to collectresponds on a Likert scale of 1 to 5, with 1 being strongly agree and 5 being strongly disagree. To encourage students' decision to utilize Edmodo for teaching and learning, the survey question was developed using the RASE (Resources, Activity, Promote, and Evaluation) method. The study's findings demonstrate that using specific Edmodo features increases student engagement and promotes responsible learning. The analysis's conclusion confirms that the students prefer Edmodo mostly for its resources. assistance and communication tools including forums, chat rooms, and online activities are also available. Students love working on online classes because of Edmodo's great and user-friendly social learning platform. The findings of this study might prompt educators to reconsider how they run their classrooms.
Classification of Motor Imagery EEG Signals Based on Data Augmentation and Convolutional Neural Networks

In brain–computer interface (BCI) systems, motor imagery electroencephalography (MI-EEG) signals are commonly used to detect participant intent. Many factors, including low signal-to-noise ratios and few high-quality samples, make MI classification difficult. In order for BCI systems to function, MI-EEG signals must be studied. In pattern recognition and other fields, deep learning approaches have recently been successfully applied. In contrast, few effective deep learning algorithms have been applied to BCI systems, especially MI-based systems. In this paper, we address these problems from two aspects based on the characteristics of EEG signals: first, we proposed a combined time–frequency domain data enhancement method. This method guarantees that the size of the training data is effectively increased while maintaining the intrinsic composition of the data. Second, our design consists of a parallel CNN that takes both raw EEG images and images transformed through continuous wavelet transform (CWT) as inputs. We conducted classification experiments on a public data set to verify the effectiveness of the algorithm. According to experimental results based on the BCI Competition IV Dataset2a, the average classification accuracy is 97.61%. A comparison of the proposed algorithm with other algorithms shows that it performs better in classification. The algorithm can be used to improve the classification performance of MI-based BCIs and BCI systems created for people with disabilities.
CONTINUUM OBSERVATIONS OF SOME HOT HELIUM-RICH STARS

Measurements are presented of the continuous energy distributions of six hot, helium-rich stars. The data have been used to determine the size of the Balmer discontinuities in all pro. gram stars and a search has been made for evidence for the presence of the helium discontinuity at A3422. Key words: helium-rich stars - spectrophotometry - Balmer and helium discontinuities
The Impact of Mobile-Assisted Social Language Learning Activities on Speaking Skills and Self-Efficacy Development

In traditional English as a foreign language (EFL) speaking classes, students have insufficient time and opportunities to practice (Zhan et al., 2015). In addition, they lack cultural and communicative contexts (Ko et al., 2021) to improve their speaking skills. Furthermore, a large number of students, especially in Asian countries, have low self-efficacy with regard to their English-speaking competence and try to avoid any activities that require speaking in public (Sun et al., 2017). In this study, we designed social language learning (SLL) activities to bridge the above-mentioned gaps and developed a mobile-assisted SLL system to support students’ participation in SLL activities. We explored how our SLL activities affect language learners’ speaking performance and self-efficacy and investigated their SLL networks and perceived acceptance of the mobile-assisted SLL system. A total of 58 graduate students were recruited for the study and randomly divided into two groups: a control group in which students completed assigned tasks using the traditional method and an experimental group in which students completed assigned tasks using the mobile SLL system. Our results showed that while the speaking skills of students in the two groups improved after the study, the learning gains of the experimental students in EFL fluency, lexis, pronunciation, and content were significantly better than those of the control students. The experimental students significantly outperformed their counterparts on the dimension of culturality, authenticity, and abundance of created verbal content. The self-efficacy of the experimental students was much better than that of the control students. The results also showed that the interaction degree of the experimental students improved, and they positively perceived applications of the mobile-assisted SLL system to EFL learning. Based on the results, several suggestions and precautions were proposed for educators and researchers in the field to consider.
Quantum computation using NMR

This article reviews recent work done by us an some initial steps towards the implementation of quantum computation using liquid state NMR. We describe how special kinds of states required for such computation (called pseudo-pure states) can be created from a thermal ensemble of spins. We demonstrate the implementation of several quantum logic gates through one- and two-dimensional NMR methods, using transition- and spin- selective pulses. Finally, we discuss the implementation of the Deutsch-Jozsa algorithm using NMR.
A study of English word category prediction based on neural networks

This paper describes word category prediction based on neural network models for constructing an accurate word recognition system. It is difficult to represent hidden linguistic structure and make an N‐gram word prediction model using traditional stochastic approaches. In this paper, two neural network models that can learn hidden linguistic structure are proposed. These models can easily be expanded from Bigram to N‐gram networks. They were tested by training experiments with an open English text database. The Trigram word category prediction rates show that neural network models are comparable to stochastic models. Trigram neural network models compress information about 150 times, which is the ratio of the Trigram stochastic model free parameters (893 = 704 969) to the neural network model link weights (4649). In addition, this paper proposes a new method that dynamically controls the training parameters, updating step size and momentum. These techniques are effective for calculating the efficiency of this system.
Validating the Chinese Version of the Personal Accountability Measure for Assessing Teachers’ Perceptions and Experiences of Teacher Accountability in China

The study aims to validate the Chinese version of Personal Accountability Measure (PAM-Ch), which is used to assess the subjective aspect of teacher accountability, by surveying 1146 teachers enrolled in professional development courses offered by a public university in Beijing. The validation process involved two phases. First, the samples were randomly divided into three subgroups—for subgroup 1 (n = 390), exploratory factor analysis was computed; for subgroup 2 (n = 359), confirmatory factor analysis (CFA) was computed; and, for subgroup 3 (n = 381), a new CFA was performed for cross-validation. Second, Cronbach’s α, composite reliability (CR), average variance extracted (AVE), maximum shared variance (MSV), and average shared variance (ASV) were calculated for testing the reliability and validity. Throughout the process, three measurement models were tested for the adaptation of the PAM-Ch in this study. The results found that Model 2 was the best fit for the data, whose factor loadings ranged from 0.72–0.95 for internal accountability (factor 1) and 0.75–0.89 for external accountability (factor 2). The CRs of these two factors were 0.963 and 0.916, respectively, and the AVE values were 0.790 and 0.645, respectively, indicating that the PAM-Ch is a reliable and valid measure.
Inter-Intra Modal Representation Augmentation With DCT-Transformer Adversarial Network for Image-Text Matching

Image-text matching has become a challenging task in the multimedia analysis field. Many advanced methods have been used to explore local and global cross-modal correspondence in matching. However, most methods ignore the importance of eliminating potential irrelevant features in the original features of each modality and cross-modal common feature. Moreover, the features extracted from regions in images and words in sentences contain cluttered background noise and different occlusion noise, which negatively affects alignment. Different from these methods, we propose a novel DCT-Transformer Adversarial Network (DTAN) for image-text matching in this paper. This work can obtain an effective metric based on two aspects: i) DCT-Transformer uses DCT (Discrete Cosine Transform) method based on a transformer mechanism to extract multi-domain common representations and eliminate irrelevant features from different modalities (inter-modal). Among them, DCT divides multi-modal content into chunks of different frequencies and quantifies them. ii) The adversarial network introduces an adversary idea by combining the original features of various single modalities and the multi-domain common representation, alleviating the background noise within each modality (intra-modal). The proposed adversarial feature augmentation method can easily obtain the common representation that is only useful for alignment. Extensive experiments are completed on the benchmark datasets Flickr30 K and MS-COCO, demonstrating the superiority of the DTAN model over the state-of-the-art methods.
Nonlinear evolution of Langmuir and electromagnetic pulses in a warm, unmagnetized plasma: modulational instability, integrability and self-focusing in 2 + 1 dimensions

The nonlinear dynamics of wave envelopes modulated in 2 + 1 dimensions is considered for two systems in plasma physics: (i) Langmuir pulses and (ii) intense (but weakly relativistic) electromagnetic (EM) pulses. Using singular perturbation techniques applied to an envelope approximation, both problems are reduced to the two-dimensional nonlinear Schrödinger (2DNLS) system, which describes the dynamics of two coupled slowly varying potentials. The general 2DNLS system exhibits a rich variety of phenomena, including enhanced (compared with ‘longitudinal’ propagation) modulational stability and (1D) soliton formation; decay of 1D solitons over long time scales; self- focusing regimes (determined by a virial-type condition); as well as integrability and 2D solitons. Applying our recent results on the 2DNLS system, we determine which of these phenomena can actually occur here and compute the parameter regimes. (i) The 2DNLS system for the Zakharov equations is modulationally unstable for all parameter values. It also has an integrable sector and a self-focusing regime. (ii) The 2DNLS system describes coupled ‘longitudinal’ and ‘transverse’ modulations of linearly or circularly polarized EM pulses propagating through a warm unmagnetized two-component neutral plasma with arbitrary masses (i.e. electron—positron or electron—ion). The pulse can accelerate particles to weakly (but not fully) relativistic velocities; relativistic, ponderomotive and harmonic effects all contribute to the nonlinear terms. The resulting 2DNLS system does not admit a self-focusing regime. Parameter values leading to an integrable case (the so-called ‘Davey—Stewartson I’ equations, which admit 2D soliton solutions) are computed; however, the required values would not be attainable in a laboratory or astrophysical setting. None the less, the existence of new nonlinear modulational instabilities associated with the second spatial degree of freedom already represents an important potential limitation on any (1 + 1)-dimensional approach to nonlinear evolution and modulational instability of plasma EM waves.
Looking for Synergies in Healthy Upper Limb Motion: A Focus on the Wrist

Recent studies on human upper limb motion highlighted the benefit of dimensionality reduction techniques to extrapolate informative joint patterns. These techniques can simplify the description of upper limb kinematics in physiological conditions, serving as a baseline for the objective assessment of movement alterations, or to be implemented in a robotic joint. However, the successful description of kinematic data requires a proper alignment of the acquisitions to correctly estimate kinematic patterns and their motion variability. Here, we propose a structured methodology to process and analyze upper limb kinematic data, considering time warping and task segmentation to register task execution on a common normalized completion time axis. Functional principal component analysis (fPCA) was used to extract patterns of motion of the wrist joint from the data collected by healthy participants performing activities of daily living. Our results suggest that wrist trajectories can be described as a linear combination of few functional principal components (fPCs). In fact, three fPCs explained more than 85% of the variance of any task. Wrist trajectories in the reaching phase of movement were highly correlated among participants and significantly more than trajectories in the manipulation phase ( $\text{p}< 0.01$ ). These findings may be useful in simplifying the control and design of robotic wrists, and could aid the development of therapies for the early detection of pathological conditions.
Association of the serum chemerin level with the development of diabetic retinopathy in patients with type 1 diabetes mellitus

Background: In patients with type 2 diabetes mellitus, the development of diabetic retinopathy (DR) correlates positively with elevated serum chemerin levels. This study was aimed at investigating the probable association between the serum chemerin level and the development of DR in patients with type 1 diabetes mellitus (T1DM). Methods: In this cross-sectional study, we included Egyptians and classified them into four groups: group 1, including healthy individuals; group 2, including patients with T1DM without DR; group 3, including patients with T1DM with non-proliferative DR (NPDR); and group 4, including patients with T1DM with proliferative DR (PDR). The assessment included best-corrected distance visual acuity assessment, slit-lamp biomicroscopy, funduscopy, fundus fluorescein angiography, and macular ocular coherence tomography. Fasting blood samples were obtained from all participants to measure serum chemerin, glycated hemoglobin (HbA1c), total cholesterol, triglyceride, and creatinine levels. Serum chemerin levels were compared among the groups, and their correlations with age, duration of diabetes, HbA1c, total cholesterol, triglyceride, and creatinine levels were analyzed. Results: We recruited 209 participants, including 46 healthy individuals in group 1, 52 patients (T1DM and no DR) in group 2, 61 patients (T1DM and NPDR) in group 3, and 50 patients (T1DM and PDR) in group 4, with comparable mean ages and sex ratios among groups. The diabetes duration, body mass index, HbA1c, total cholesterol, triglyceride, and serum chemerin levels differed significantly among the groups (all P < 0.001), whereas the creatinine level did not (P > 0.05). The serum chemerin level was significantly higher in group 4 than in groups 3 and 2, in group 3 than in group 2, and in groups 3 and 4 than in group 1 (all P < 0.001). However, it was comparable between groups 1 and 2 (P > 0.05). It correlated with the duration of T1DM and HbA1c, total cholesterol, triglyceride, and creatinine levels but not with age. Conclusions: Patients with T1DM with DR showed higher serum chemerin levels than those with T1DM without DR or healthy individuals. Serum chemerin levels were higher in those with PDR than in those with NPDR. Thus, serum chemerin levels are a potential biomarker of the development and severity of DR in patients with T1DM. Nevertheless, future diagnostic accuracy studies are required to confirm these potential applications.
High-Order Quasi-Elliptic Bandpass Filters Using Mixed EM Coupling Hairpin-Comb Resonators

Mixed electric and magnetic (EM) coupling hairpin-comb resonators and their applications in third- and fifth-order bandpass filters are presented in this paper. By adjusting the coupling lengths and the distances between the resonators, the coupling coefficient can be changed to desired values. Meanwhile, the mixed EM coupling contributes to a controllable transmission zero. Design and fabrication of the proposed third- and fifth-order filters show the advantages. N–1 transmission zeros are realized by N resonators without cross-coupling or source-load coupling. The selectivity of passband is outstanding. The locations of the transmission zeros can be precisely described. Moreover, it is convenient to design high-order inline filter with quasielliptic response.