Miracle-dz/UniFAR-FTUs huggingface dataset:
X-Ray and Gamma-Ray Emission of the Shell-Type Supernova Remnant RX J1713.7-3946

To study possible origins of high-energy gamma-ray emission from shell-type supernova remnants, RX J1713.7-3946, we model their nonthermal photon spectra from X-ray to very high energy (VHE) gamma-ray bands in the frame of non-linear diffusive shock acceleration, respectively. In our modeling, the accelerated proton spectrum is calculated based on a semi-analytical solution of the problem of particle acceleration at non-linear shock waves with a free escape boundary at some location upstream, and the accelerated electron spectrum is similar to the proton's spectrum when the electron's momentum is much less than its maximum momentum, which is determined by equating the synchrotron loss time with the acceleration time, and the cutoff shapes are assumed to be an super-exponential. In the one-zone model, we calculated the non-thermal photon spectra of the supernova remnants (SNR) for both leptonic and hadronic cases, and found out that the spectra calculated for both cases can reproduce the observed data by Suzaku, Fermi LAT, and HESS under reasonable model parameters. However, high-energy gamma-ray emission would have a hadronic origin if the observed thickness of the X-ray filament of the SNR is taken into account.
Assessment of Nutritional Quality of Products Sold in University Vending Machines According to the Front-of-Pack (FoP) Guide

The aim of this research was to assess the nutritional composition of 654 foods and beverages from vending machines on a University Campus. The guide called “Creating a front of pack nutrition label for pre-packed products sold through retail outlets” from the Department of Health (UK) was used to assess the nutritional composition and to compare values from food and beverage categories. A high proportion of food items had high–moderate content of nutrients related to chronic disease (93, 88, 74 and 49% had high–moderate content of fat, saturated fat, salt and sugar, respectively). On the other hand, a few beverages had high–moderate content of these nutrients, except for sugar (2% high to moderate in fat, 2% in saturated fat, 0% in salt and 39% in sugar). The most frequent food categories were chocolates and bars (10.6%) and breadsticks (8.4%), whereas the most available beverages were water (27.7%) and soft drinks (23.4%). There were no statistically significant differences in the proportion of categories between the health science and humanities faculties, except for energy drinks (p < 0.05) and soft drinks (p < 0.05). Vending machines contribute to an obesogenic environment and do not support healthy snacking. Recommendations in this article should be considered to develop official guidelines to ensure the wider availability of healthy dietary choices in vending machines in university settings.
Synoptic and Topographic Variability of Northern California Precipitation Characteristics in Landfalling Winter Storms Observed during CALJET

Abstract Observations from northern California during the California Landfalling Jets (CALJET) experiment are used to examine the mean characteristics of precipitation and their variances as functions of synoptic and topographic regimes. Ten cases involving the landfall of extratropical cyclones are analyzed with radar and rain gauge data collected at two sites: one in the coastal mountains north of San Francisco (CZD) and the other in the Central Valley just west of Sacramento (KDAX). Aside from the melting-layer bright band, the most striking feature in the 10-case composite vertical profile of radar reflectivity at CZD was a distinct change in slope about 2.5 km above the bright band. This “shoulder” is thought to represent a change in the growth rate of hydrometeors. Although the bright band was quite distinct, about one-third of the profiles in the composite did not exhibit this feature. These nonbrightband (NBB) profiles had a low-level slope where reflectivity increased with decreasing altitude, a .
Stereographic projection for three‐dimensional global discontinuous Galerkin atmospheric modeling

A method to solve the three‐dimensional compressible Navier‐Stokes equations on the sphere is suggested, based on a stereographic projection with a high‐order mapping of the elements from the stereographic space to the sphere. The projection is slightly modified, in order to take into account the domain thickness without introducing any approximation about the aspect ratio (deep‐atmosphere). In a discontinuous Galerkin framework, the elements alongside the equator are exactly represented using a nonpolynomial geometry, in order to avoid the numerical issues associated with the seam connecting the two hemispheres. This is an crucial point, necessary to avoid mass loss and spurious deviations of the velocity. The resulting model is validated on idealized three‐dimensional atmospheric test cases on the sphere, demonstrating the good convergence properties of the scheme, its mass conservation, and its satisfactory behavior in terms of accuracy and low numerical dissipation. A simulation is performed on a variable resolution unstructured grid, producing accurate results despite a substantial reduction of the number of elements.
The Use of Stroboscopic Patterns in the Determination of Speeds of Rotation

The use of stroboscopic patterns for fixing and measuring rotational speeds is discussed. Patterns having as many as nine bands may be utilized. The patterns occur in a definite recurring sequence, according to a simple numerical relation. Most of the speeds intermediate to those at which patterns are stationary may be obtained by correcting for the precession or recession of the patterns.
Formulation and optimization of cubic polynomial joint trajectories for industrial robots

Because of physical constraints, the optimum control of industrial robots is a difficult problem. An alternative approach is to divide the problem into two parts: optimum path planning for off-line processing followed by on-line path tracking. The path tracking can be achieved by adopting the existing approach. The path planning is done at the joint level. Cubic spline functions are used for constructing joint trajectories for industrial robots. The motion of the robot is specified by a sequence of Cartesian knots, i.e., positions and orientations of the hand. For an N -joint robot, these Cartesian knots are transformed into N sets of joint displacements, with one set for each joint. Piecewise cubic polynomials are used to fit the sequence of joint displacements for each of the N joints. Because of the use of the cubic spline function idea, there are only n - 2 equations to be solved for each joint, where n is the number of selected knots. The problem is proved to be uniquely solvable. An algorithm is developed to schedule the time intervals between each pair of adjacent knots such that the total traveling time is minimized subject to the physical constraints on joint velocities, accelerations, and jerks. Fortran programs have been written to implement: 1) the procedure for constructing the cubic polynomial joint trajectories; and 2) the algorithm for minimizing the traveling time. Results are illustrated by means of a numerical example.
Suivi d'objets multiples représentés par leurs frontières pour l'interpolation temporelle dans une séquence d'images

In this paper we present a boundary-based representation of a motionbased image sequence segmentation. A tracking algorithm is associated to this structure which is able to handle several objects simultaneously, in the presence of partial occlusions. This segmentation representation consists in the boundaries between all couples of adjacent regions approximated by a polygonal line. We extend it with a label on each boundary indicating to which region it is belonging from a motion point of view. This information is useful for an efficient predictive tracking of this representation over time. Moreover, we show that the structural information enclosed in our representation is very useful when regions are occluding. This representation can be used for multiple purposes in image sequence analysis (for example region fusion, layering) as well as coding and multimedia applications (for instance motion-compensated compression, temporal interpolation, object manipulation). Among many applications, we particularly consider a temporal image sequence interpolation which can be done at the receiver end of a coder/decoder chain.
Above-band gap two-photon absorption and its influence on ultrafast carrier dynamics in ZnTe and CdTe

We present measurements of transient carrier dynamics subsequent to intense above-band gap femtosecond excitation of the II–VI compounds ZnTe and CdTe, probed in the far infrared by transient terahertz time-domain spectroscopy. The intensity and temperature dependence of the carrier dynamics illuminates the role of two-photon absorption (TPA) of pump photons. At cold temperatures and high excitation intensities TPA results in a photoexcited carrier distribution which requires several picoseconds to thermalize. As a consequence, the dielectric function of the carrier distribution deviates strongly from the Drude model for as long as 20 ps after excitation.
Real-Time FPGA Simulation of High-Voltage Silicon Carbide MOSFETs

This article presents a real-time field-programmable gate array (FPGA)-based dynamic model of high-voltage and high-current silicon carbide (SiC) metal-oxide-semiconductor field-effect transistor (mosfet) half-bridge power modules. The dynamic switching model utilizes the Shichman and Hodges equations using voltage-dependent nonlinear device capacitances and module electrical parameters to obtain an accurate dynamic model of the device switching transients. The key device states gate-source voltage, drain current, and drain-source voltage are modeled and discretized using forward Euler discrete integration method. Analysis of synthesizing the discrete-time model into real-time FPGA-based system with real-time data output from the on-board digital-to-analog converter is presented in detail. The model is utilized in modeling a 320-kW, medium-voltage dc/dc dual-active bridge converter and verified using dynamic experimental results from a 3.3-kV SiC mosfet half-bridge power module. It has been shown that the presented discrete-time dynamic switching model accurately describes the turn-on and turn-offswitching transients of the SiC power module at various voltage and current levels. Such models are useful for rapid and cost effective design and prototyping of SiC-based power electronic systems by defining key design and operating parameters, such as deadtime, switching frequency, and switching losses.
Equilibrium charge-state distributions for heavy ions exiting carbon foils

It has been recently shown that equilibrium charge-state distributions (ECSD's) of heavy ions exiting carbon foils are well fitted by the ${\ensuremath{\chi}}^{2}$ model, the Gaussian model, and the reduced ${\ensuremath{\chi}}^{2}$ model in the low-, intermediate-, and high-velocity regions, respectively. A qualitative interpretation of these statistical distributions is given in the present work, and it is pointed out that the reduced ${\ensuremath{\chi}}^{2}$ model is mathematically identical to the ${\ensuremath{\chi}}^{2}$ model if the charge state $i$ is replaced by $Z\ensuremath{-}i$($Z$ is the projectile atomic number) in the probability density function. This equivalence is physically explained by the existence of a charge-state limitation in these two velocity regions. The author discusses also the validity of semiempirical relations giving the mean charge $\overline{i}$ and the standard deviation of the charge $s$ in the different velocity domains. At sufficiently high velocities $\frac{E}{M}\ensuremath{\gtrsim}100$ keV ${\mathrm{amu}}^{\ensuremath{-}1}$, $Z\ensuremath{\lesssim}20$, experimental data available seem to indicate that $\overline{i}$ and $s$ depend monotonically on $Z$ and $v$, but this is not the case at lower velocities where shell effects play a major role. Finally, the author analyzes ECSD's observed for heavy ions, $59\ensuremath{\lesssim}Z\ensuremath{\lesssim}82$, at low energies $\frac{E}{M}\ensuremath{\lesssim}7$ keV ${\mathrm{amu}}^{\ensuremath{-}1}$) and finds that these ECSD's are also very well fitted by the ${\ensuremath{\chi}}^{2}$ model proposed previously for lighter ions, $Z\ensuremath{\lesssim}26$, at $\frac{E}{M}\ensuremath{\lesssim}20$ keV ${\mathrm{amu}}^{\ensuremath{-}1}$. However, for these heavy ions, ECSD's are already Gaussian for $\frac{E}{M}\ensuremath{\gtrsim}5$ keV ${\mathrm{amu}}^{\ensuremath{-}1}$.
Electron spin exchange of shallow donor muonium states

Shallow donor muonium states with small hyperfine frequencies, recently observed in II–VI semiconductor compounds, have a number of unique features that present both opportunities and challenges in understanding muon spin dynamics in the presence of Heisenberg spin exchange. First, the shallow muonium state in CdSe with hyperfine frequency ω0/2π ≈ 0.1 MHz is already in the high field regime even in the earth's magnetic field, where only two precession frequencies are observable by the muon spin rotation (μSR) technique. Second, unlike in the case of more conventional muonium species with a larger hyperfine frequency, the μSR signal of shallow muonium states can be observed even in the transition region, between the slow spin–flip regime and the fast spin–flip regime, where the spin–flip rate and the hyperfine frequency are comparable. The muon spin dynamics in the transition region has not been theoretically explored previously, mainly because normal muonium in vacuum gives no observable signal in this region. Third, in the case of shallow muonium states, the incoherent process defined to be those spin–flip collisions that cause changes in muon spin precession frequencies, becomes crucially important in the transition region, where the incoherent process is entirely negligible in more conventional muonium species. By taking incoherent multiple collisions into account, an analytical expression for the time evolution of the muon spin polarization in Mu is derived, where Mu undergoes repeated spin–flip collisions. Comparisons with Monte Carlo calculations show that the analytical expression obtained in this work can reliably be used to analyse experimental data for shallow donor states not only in the slow spin–flip regime, but also in the transition region up to the onset of the fast regime. The present work confirms a recent experimental finding that, in the transition region, the initial phases of the two precession components of shallow donor states exhibit a strong and unexpected dependence on the spin–flip rate. Such a rate-dependent initial phase is expected to be widely observed in Mu species with hyperfine frequencies less than several tens of megahertz. In order to understand spin dynamics in the transition region in a wider and more general context, Monte Carlo calculations are also carried out for more conventional muonium species with large hyperfine frequencies in which no observable signal can be seen in a transverse field in the transition region and in a large part of the fast regime.
Kinetic simulations of the Kelvin-Helmholtz instability at the magnetopause

Two-dimensional hybrid simulations with particle ions and fluid electrons are used to calculate the kinetic evolution of the Kelvin-Helmholtz instability for a magnetopauselike configuration. The unidirectional magnetic field is essentially transverse to the plasma flow velocity, which is the most unstable case according to linear theory and models the flow dynamics in the subsolar region of the magnetopause for northward interplanetary magnetic field. We recover effects analogous to those found in MHD simulations, including a mode cascade to longer wavelengths. The boundary layer consists of coherent structure and is not well described by a diffusive process. Isolated structures on the order of the ion gyroradius are formed which can cross the boundary in either direction. We describe how the time evolution of these structures represents transport across boundary layers, and we consider the possible connection of these entities to flux transfer events and other structure seen in the low-latitude boundary layer at the Earth's magnetopause as well as to flux ropes commonly observed near the ionopause of Venus. We also discuss the relation of the hybrid calculations to previous MHD simulations and to observations.
Comparison of Systemic Financial Risks in the US before and after the COVID-19 Outbreak - A Copula-GARCH with CES Approach

The analysis and prediction of systemic financial risks in the US during the COVID-19 pandemic is of great significance to the stability of financial markets in the US and even the world. This paper aims to predict the systemic financial risk in the US before and during the COVID-19 pandemic by using copula–GJR–GARCH models with component expected shortfall (CES), and also identify systemically important financial institutions (SIFIs) for the two comparative periods. The empirical results show that the overall systemic financial risk increased after the outbreak of the COVID-19 pandemic, especially in the first half of the year. We predicted four extreme risks that were basically successful in capturing the high risks in the US financial markets. Second, we identified the SIFIs, and depository banks made the greatest contribution to systemic risk from four financial groups. Third, after the outbreak of the epidemic, the share of Broker–Dealer and Other Institutions in the overall systemic risk has apparently increased. Finally, we recommend that the US financial regulators should consider macro-prudential guidance for major financial institutions, and we should pay more attention to Broker–Dealers, thereby improving the financial stability of the US and the global financial markets.
Students' Perceptions About Teachers' Competence Through Student Learning Motivation and its Implications on Learning Outcomes of Economic Subjects

Background: The problem in this study is about the low economic learning outcomes obtained by students based on the average score of the national exams for SMA Negeri in Kuningan Regency in 2015-2019 which tends to fluctuate. AIM: The purpose of this study was to determine the direct and indirect effect of students' perceptions of teacher competencies consisting of personality, pedagogic, professional, and social competencies on learning motivation and their implications for learning outcomes. Method: This research is quantitative research with a survey method using the Area Probability Sample technique. The population of this research is all students of class XI IPS SMA Negeri in Kuningan Regency, totaling 2,676 students spread over 19 schools. As for the research sample as many as 316 students spread over 10 schools. The data analysis technique used path analysis. Based on the results of the descriptive analysis of student perceptions of teacher competence, learning motivation, and learning outcomes, they are in a good category. The results of path analysis obtained the regression equation = 0.108? 1 + 0.301? 2 + 0.241? 3 + 0.418? 4 + 0.355? 1 and = 0.064? 1 + 0.168? 2 + 0.290? 3 + 0.276? 4 + 0.252? + 0.342? 2. The results of the path analysis show that there is a direct influence on students' perceptions of personality competence at 10.8%, pedagogic competence by 30.1%, professional competence at 24.1%, and social competence by 41.8% learning motivation. The direct influence of students' perceptions of personality competence is 6.4%, pedagogic competence is 16.8%, professional competence is 29% and social competence is 27.6% on learning outcomes. The indirect effect of students' perceptions of personality competence gets a count of 2.24, pedagogic competence count of 4.35, professional competencies get a count of 2.77, and social competence gets a count of 2.97, which means it is greater than table 1.97, which means on the indirect effect of learning outcomes through learning motivation Findings: Students' perceptions of teacher competencies which consist of personality, pedagogic, professional, and social competencies have a positive and significant impact on learning motivation and implications for learning outcomes both directly and indirectly.f
Experimental demonstration of plasmonic-grating-assisted optical biosensor

We experimentally demonstrate the possibility to implement an optical bio-sensing platform based on the shift of the plasmonic band edge of a 2D-periodic metal grating. Several 2D arrangements of square gold patches on a silicon substrate were fabricated using electron beam lithography and then optically characterized in reflection. We show that the presence of a small quantity of analyte, i.e. isopropyl alcohol, deposited on the sensor surface causes a dramatic red shift of the plasmonic band edge associated with the leaky surface mode of the grating/analyte interface, reaching sensitivity values of ~650nm/RIU. At the same time, dark field microscopy measurements show that the spectral shift of the plasmonic band edge may also be detected by observing a change in the color of the diffracted field. Calculations of both the spectral shift and the diffracted spectra variations match the experimental results very well, providing an efficient mean for the design of sensing platforms based on color observation.
Temperature Dependence of the Dielectric Permittivity of BaTiO3-CoFe2O4 Ceramic Composites

Two-phase ceramic composites of cobalt ferrite dispersed in a barium titanate matrix were prepared and their dielectric permittivity was characterized. A rounding of their dielectric constant near the ferroelectric transition temperature of the BaTiO 3 phase was observed. A generalized brick-wall model, taking into account the BaTiO 3 contribution, fitted with the Landau-Devonshire theory, and the CoFe 2 O 4 permittivity, experimentally determined, was used in order to obtain their effective dielectric constant. The effective model was applied to the discussion and fitting of the temperature dependence of the dielectric permittivity of the composites. The Landau-Devonshire coefficients for the BaTiO 3 phase were also obtained.
The Role of the North American Topography on the Maintenance of the Great Plains Summer Low-Level Jet*

Abstract Summer precipitation over the central United States depends strongly on the strength of the Great Plains low-level jet (LLJ). The Geophysical Fluid Dynamics Laboratory’s new generation of the atmospheric general circulation model (GCM) and the linear and nonlinear stationary wave models are used in this study to examine the role of North American topography in maintaining the Great Plains summer mean LLJ and precipitation. Atmospheric GCM experiments were first performed with and without the North American topography and with prescribed climatological sea surface temperatures. Results show that the Great Plains LLJ disappears completely in the experiment when the North American topography is removed, while the summer seasonal mean LLJ is well simulated in the experiment with full earth topography. In the absence of the North American topography, the summer precipitation is significantly reduced over the central United States and increased along the Gulf States and northeast Mexico. Linear and non.
Far Ultraviolet Spectroscopic Explorer Observations of the Low-Mass X-Ray Binary 2A 1822−371 (V691 Coronae Australis)

FUSE observations were taken around the 5.57 hr binary orbit of the low-mass eclipsing X-ray binary 2A 1822-371 (V691 CrA). The spectra are presented in four phase bins, corresponding to the observing windows from the FUSE satellite. We describe the far-ultraviolet flux, the O VI emission, and their changes through the binary orbit, and compare them with previous optical studies.