Miracle-dz/UniFAR-FTUs huggingface dataset:
Suprathermal electrons generated by the interaction of powerful radio wave with the ionosphere

We present two sets of observations of suprathermal electrons, produced by the interaction of powerful radio wave with the ionosphere, as seen using the incoherent scatter radar (ISR) technique. The observational data are compared with the theory of multiple acceleration of electrons in the strongly excited resonance region near the reflection point of the powerful radio wave. The structure of the wide perturbed region filled with energetic (10–20) eV electrons is determined. The size of this region along the Earth magnetic field is shown to be 100 km. The full power going to the accelerated particles is determined: it is 6–8 kW or (4–6)% of the entire HF radiated power. The power carried by the suprathermal electrons flux escaping into magnetosphere is of the order l kW.
Automated preparation of high‐quality epitaxial graphene on 6H‐SiC(0001)

In this contribution, we present details on a recently installed hot‐wall reactor for graphene growth on silicon carbide (SiC) in argon under atmospheric pressure. Both preparation steps, i.e., the preconditioning of the SiC substrate by hydrogen etching and the graphene growth are performed in this setup in a fully automated manner thus ensuring the preparation of high‐quality graphene on an everyday basis. Samples were characterized by atomic force microscopy and X‐ray induced photoelectron spectroscopy. We present results on the optimization of the hydrogen etching procedure. The thickness distribution of graphene samples grown in the automated process is Gaussian with a mean value of 1.1 monolayers and a standard deviation of 0.17 monolayers. This indicates a highly controlled process.
Pseudo Conditional Maximum Likelihood Estimation of the Dynamic Logit Model for Binary Panel Data

We show how the dynamic logit model for binary panel data may be approximated by a quadratic exponential model. Under the approximating model, simple sufficient statistics exist for the subject-specific parameters introduced to capture the unobserved heterogeneity between subjects. The latter must be distinguished from the state dependence which is accounted for by including the lagged response variable among the regressors. By conditioning on the sufficient statistics, we derive a pseudo conditional likelihood estimator of the structural parameters of the dynamic logit model, which is simple to compute. Asymptotic properties of this estimator are studied in detail. Simulation results show that the estimator is competitive in terms of efficiency with estimators recently proposed in the econometric literature.
Numerical study of nonlinear forced magnetic reconnection.

Two-dimensional numerical simulations are used to investigate nonlinear aspects of forced magnetic reconnection in a zero β highly conducting plasma. This is representative of the solar corona, where reconnection may be induced by external perturbations, e.g., at the photospheric boundary of the corona. The aim is to investigate the energy dissipation by the reconnection, which may provide a mechanism for heating the coronal plasma. The field is taken to be initially a sheared force-free equilibrium in a slab, and the effects of applying a slow deformation to the boundaries are investigated. Previous analytical studies assuming small departures from the initial equilibrium have found that a current sheet forms during an initial ideal phase of evolution, which subsequently relaxes to a reconnected equilibrium, releasing some magnetic energy. The linear theory predicts that the energy release has a singularity when the field is marginally stable to the tearing mode. The nonlinear evolution of the field is c.
Mixed H 1 and Passive Filtering for A Class of Nonlinear Switched Systems with Unstable Subsystems

This paper investigates the mixed H 1 and passive ﬁltering problem for a class of nonlinear switched systems with unstable subsystems. The mixed weighted H 1 and passivity performance index is proposed for switched systems. This new performance index covers the weighted H 1 performance index and the passivity performance index as special cases. Therefore, based on this new performance index, the weighted H 1 ﬁltering problem and the passive ﬁltering problem for nonlinear switched systems with unstable subsystems are solved in a uniﬁed framework. The Takagi–Sugeno (T–S) fuzzy model is an effective tool in approximating most complex nonlinear systems, which utilizes local linear system description for each rule. Using the T–S fuzzy model to approximate each nonlinear subsystem, the nonlinear switched systems are modeled as the switched T–S fuzzy systems. The states of the ﬁltering error system constructed by the augmentation technique will be divergent when unstable subsystems are activated. To overcome this problem, a set of mode-dependent ﬁlters of a Luenberger-like observer type are constructed in this paper. The multiple Lyapunov functions approach and the average dwell time technique are employed to solve the ﬁltering problem. New sufﬁcient conditions for the existence of mixed H 1 and passive ﬁlters are developed, which ensure the ﬁltering error system to be asymptotically stable with a prescribed mixed H 1 and passivity performance index. Moreover, the desired mixed H 1 and passive ﬁlters can be constructed by solving a set of linear matrix inequalities. Finally, two numerical examples are given to demonstrate the effectiveness and advantage of the obtained results.
Quantum versus classical dynamics in the treatment of multiple photon excitation of the anharmonic oscillator

The response of a one‐dimensional anharmonic Morse oscillator to an intense electromagnetic field has been investigated using both a quasiclassical and quantum mechanical description of the oscillator. The anharmonic nature of the Morse potential reduces the coherence of the quantum excitation process after only a few quanta have been absorbed. The classical and quantum behavior of averaged quantities such as the energy absorbed and the oscillator displacement as a function of time are in good agreement; however, the classical description cannot reproduce the multiphoton resonances. We are led to the conclusion that classical mechanics provides an adequate description of the response of a molecule in an intense laser field provided that multiphoton resonances do not individually play a fundamental role in the process.
Stability analysis of an embankment resting upon a column‐reinforced soil

The design against failure of an embankment resting upon a soft soil improved by a group of columns is investigated with the help of the yield design homogenization approach. Assuming that both constituents of the reinforced ground are purely cohesive materials (‘lime column’ technique), an upper bound estimate for the macroscopic strength condition of the reinforced soil as a homogenized medium is first obtained, providing definite evidence of a shear strength anisotropy associated with the reinforcement preferential orientation. The kinematic method of yield design is then performed on the basis of such a criterion, making use of rotational failure mechanisms involving slip circles in the reinforced ground. Upper bound estimates are finally obtained for the embankment stability factor, as functions of the degree of reinforcement and relative thickness of the soil layer. These results are compared with those derived from a simplified analysis, where the reinforced soil is assumed to exhibit an averaged isotropic cohesion. This comparison clearly indicates that the latter simplified analysis may produce quite unsafe estimates for the embankment stability, which can be attributed to the fact that it fails to capture the inherent strength anisotropy of the reinforced soil. Copyright © 2010 John Wiley & Sons, Ltd.
Model of an Autonomous Monitoring System Based on Long Range Technology

The article presents the results of the development of an integrated monitoring system based on the use of various methods of positioning and wireless transmission of information. The system is based on the use of modern technologies for data transmission over long distances. LoRa technology is at the heart of solving the problem of information transfer and data exchange. The task of monitoring the parameters of the control zone is performed on the basis of data from a distributed network of various sensors that determine the actual parameters and transmit them to the server through a network of relay data transmission nodes. A feature of the presented model is the possibility of forming an autonomous monitoring system that allows you to control the parameters of the atmosphere, the radiation background in hard-to-reach areas, as well as areas where the functioning of stationary systems is disrupted, etc. The positioning problem is solved based on the use of GNSS data. The task of detecting failures in GNSS data reception, as well as the presence of interference, can be solved by applying positioning methods based on signal parameter processing methods. The complex solution proposed in the paper allows us to consider it as one of the alternative systems for monitoring tasks, both on stationary and mobile ground (air, sea) based platforms. Theoretical provisions are confirmed by the results of the experiment to test the functioning of the network of relay nodes for the transmission of coordinate information of the monitoring position with the function of controlling the parameters of the received data packet. The presented model of an autonomous monitoring system can be an element of a decision support system, which is due to the possibility of obtaining actual information about the state of the control object.
A Feasibility Study of Remote Non-Contact Vital Signs (NCVS) Monitoring in a Clinic Using a Novel Sensor Realized by Software-Defined Radio (SDR)

The COVID-19 outbreak has caused panic around the world as it is highly infectious and has caused about 5 million deaths globally. A robust wireless non-contact vital signs (NCVS) sensor system that can continuously monitor the respiration rate (RR) and heart rate (HR) of patients clinically and remotely with high accuracy can be very attractive to healthcare workers (HCWs), as such a system can not only avoid HCWs’ close contact with people with COVID-19 to reduce the infection rate, but also be used on patients quarantined at home for telemedicine and wireless acute-care. Therefore, we developed a custom Doppler-based NCVS radar sensor system operating at 2.4 GHz using a software-defined radio (SDR) technology, and the novel biosensor system has achieved impressive real-time RR/HR monitoring accuracies within approximately 0.5/3 breath/beat per minute (BPM) on student volunteers tested in our engineering labs. To further test the sensor system’s feasibility for clinical use, we applied and obtained an Internal Review Board (IRB) approval from Texas Tech University Health Sciences Center (TTUHSC) and have used this NCVS monitoring system in a doctor’s clinic at TTUHSC; following testing on 20 actual patients for a small-scale clinical trial, we have found that the system was still able to achieve good NCVS monitoring accuracies within ~0.5/10 BPM across 20 patients of various weight, height and age. These results suggest our custom-designed NCVS monitoring system may be feasible for future clinical use to help combatting COVID-19 and other infectious diseases.
ERA-CLIM: Historical Surface and Upper-Air Data for Future Reanalyses

Future reanalyses might profit from assimilating additional historical surface as well as upper-air data. In the framework of the European Reanalysis of Global Climate Observations (ERACLIM; www.era-clim.eu) project, significant amounts of pre-1957 upper-air and surface data have been cataloged (>2.5 million station days), imaged (>450,000 images), and digitized (>1.25 million station days) to prepare new input datasets for upcoming reanalyses. These data cover large parts of the globe, focusing henceforth on less well-covered regions such as the tropics, the polar regions, and the oceans and on very early twentieth-century upper-air data from Europe and the United States. The total numbers of digitized/inventoried records (i.e., time series of meteorological data at fixed stations or from moving observational platforms) are 80/214 (surface), 735/1,783 (upper air), and 61/101 [moving upper-air (i.e., data from ships, etc.)]. Here, the authors give an overview of the data rescue activities, the data, and t.
The space frequency and origin of the runaway O and B stars

Determinations of space frequency for runaway O and B stars are in very poor agreement, and many possible sources of systematic errors have been put forward. This paper investigates these sources, as well as others, and presents means for determining unbiased (true) space frequencies. When corrected for major sources of systematic error, space frequency determinations for the runaway O stars are in very good agreement but less so for the B-type runaways. The true space frequencies of runaway O and B stars are, respectively, 46 percent and 4 percent, as discussed in this paper. The former value is very supportive, along with other arguments presented in this paper, for runaway O stars being produced from supernova explosions in massive binaries. The origin of the B-type runaways is less clear. 89 refs.
A Virtual Spine Construction Algorithm for a Patient - Specific Pedicle Screw Surgical Simulators

This paper presents an underlying study of a virtual spine construction as part of a surgical simulator. The goal is to create a patient - specific segmentation and rendering algorithm in two aspects, namely geometric modelling and material properties estimation. The spines are isolated from the CT scan data using an in house segmentation algorithm based on U - Net architecture, which are then rendered using the marching cube algorithm. Two rendering parameters (step size and voxel size) are tuned to give the best visual result. The material property are extracted from the gray scale values of the CT scan. The developed algorithm are bench - marked against an open source segmentation software.
Analyzing the effects of digital marketing on brand awareness among internet users

Information technology advancements have influenced how marketing is carried out in the sector with that, a variety of platforms and methods for raising consumer brand awareness. Digital marketing strategies such as advertising, social media marketing, content marketing, email marketing, and website marketing are well-known and used across a variety of industries in our fast-evolving technology. This article provides a thorough analysis of how various digital marketing strategies related to brand recognition. In light of this, the study design for this work is comparative causal, and the primary data used were those that were gathered from 273 consumers of digital media in the province of Riau Island and evaluated using the SmartPLS program. The theory was put to the test, and the results revealed a significant positive association between internet advertising and brand recognition. The study can be further expanded using data from various age groups, geographic locations, and other digital marketing strategies which wasn’t further studied in this study.
“Highly Qualified” to Do What? The Relationship Between NCLB Teacher Quality Mandates and the Use of Reform-Oriented Instruction in Middle School Mathematics

The federal No Child Left Behind Act of 2001 (NCLB) calls for a highly qualified teacher in every classroom. According to the legislation, “highly qualified” is defined as full certification, a bachelor’s degree, and demonstrated content knowledge in all core subjects taught. States, district, and schools are spending considerable resources addressing these provisions, but to what degree are the readily available measures of teacher qualifications associated with the type of teaching advocated by standards-based reform? The authors examine the relationships among educational credentials, preparedness to teach content, participation in professional development, and use of reform-oriented instruction by middle school mathematics teachers using data from the 2000 National Assessment of Educational Progress (NAEP). Their analyses suggest that preparedness to teach mathematics content and participation in content-related professional development activities are associated with reform-oriented teaching, measured here as increased emphases on conceptual learning goals for students and increased use of reform-oriented teaching strategies.
Comparison of the ultraviolet absorption cross section of buckminsterfullerene in the gas phase and in hexane solution

Five previously reported measurements of the gas-phase absorption cross section for in the ultraviolet region are reviewed in the light of recent improvements in the determination of vapour pressure. An improved gas-phase absorption cross section at is presented and compared with a cross section derived from absorbance measurements in hexane solution by applying the (refractive index-dependent) Chako correction. The agreement between the measured gas-phase absorption cross section and that derived from the solution phase absorbences is very good. The highest energy absorption band (band G, 209 nm) is suppressed in intensity and shifted lower in energy more than the other two bands, E (254 nm) and G (326 nm).
Techno-economic assessment of photovoltaic-based charging stations for electric vehicles in developing countries

ABSTRACT Many countries are planning their transition to renewable-energy-powered transportation sectors. Among those are developing countries, like Jordan, which face financial burdens in the actual implementation due to their economic status. As the penetration of electric vehicles increases, more green-charging stations will be required. Therefore, to encourage investors to initiate the deployment phase, this work presents a better mapping and comparison method for Photovoltaic (PV) battery charging stations across Jordan. It provides a better visual of the stations’ techno-economic performance, so financiers can use it as a guide to building their future stations, given the economic returns presented, particularly since the designed algorithm considered profit-maximization of the highest priority. All the tested PV-battery configurations; namely, PV-Li-Ion, PV-Zn-Br, PV-Lead-acid, PV-Redox flow, and PV-Li-Ion second life, were feasible, with the southern parts of Jordan being more favorable for installation in terms of the techno-economic parameters. However, a PV-Zn-Br station was found to have the highest annual profit of $7,535 with 2.63 years return of investment and a renewable fraction of 96.7%. Finally, although the obtained results discussed the specifics of Jordan, this work can be extended to any other country planning its transition to a green transportation sector; to improve deployment by attracting investors.
Experimental study of the dynamics of conditionally averaged structures in weakly developed electrostatic turbulence

An experimental study of coherent structures in the electrostatic turbulence observed in a steady-state operated, magnetized, cylindrical low-β argon plasma is presented. The conditional averaging technique is used to detect and to characterize large-scale conditional structures. The results of conditional averaging of a single drift wave mode are consistent with theoretical predictions and the data obtained by an azimuthal array of 64 Langmuir probes. In the turbulent regime, large monopole structures in the density fluctuations are identified, which develop by particle trapping due to associated potential structures. These structures lead to transport of particles across magnetic field lines, as evident from the trajectory of the structures. The comparison of the dynamics of conditional structures and unaveraged spatiotemporal structures suggests that they are of the same origin.
Monotone Piecewise Cubic Interpolation

In a 1980 paper [SIAM J. Numer. Anal. , 17 (1980), pp. 238–246] the authors developed a univariate piecewise cubic interpolation algorithm which produces a monotone interpolant to monotone data. This paper is an extension of those results to monotone $\mathcal{C}^1 $ piecewise bicubic interpolation to data on a rectangular mesh. Such an interpolant is determined by the first partial derivatives and first mixed partial (twist) at the mesh points. Necessary and sufficient conditions on these derivatives are derived such that the resulting bicubic polynomial is monotone on a single rectangular element. These conditions are then simplified to a set of sufficient conditions for monotonicity. The latter are translated to a system of linear inequalities, which form the basis for a monotone piecewise bicubic interpolation algorithm.
Indoor 3D Localization Using Monocular Vision

At present, global positioning system (GPS) basically meet the user's needs for location services in outdoor scenes. However, it is difficult to locate where GPS signals are missing in indoor environment. In this paper, we design an indoor localization system based on monocular vision. Firstly, according to the pictures taken by the terminal camera in real time, the feature points of each picture are extracted, and then the position and pose of the monocular camera are estimated by using the direct method to match the features. In order to estimate the three-dimensional depth of feature points, this paper use the depth filter to establish a real time sparse point cloud map. Finally, the real environment is simulated by using the three-dimensional visualization tool RVIZ. The experimental results show that the positioning accuracy of the proposed method in indoor environment can reach 0.04m.
Estimation of the Pareto scale parameter based on grouped data

Abstract We considered point estimation of the scale parameter of the Pareto distribution using grouped data. The maximum likelihood estimator in this situation has no closed form and requires an iterative numerical procedure. Several other estimators that exist in closed form are suggested. Their behavior is examined and compared with the maximum likelihood estimator under a variety of experimental conditions. The results show that some of the suggested estimators have statistical performance which is comparable with that of the maximum likelihood estimator.