Miracle-dz/UniFAR-FTUs huggingface dataset:
An Efficient Interpolation Procedure for High-Order Three-Dimensional Semi-Lagrangian Models

Abstract An efficient method is proposed for performing the grid interpolations required at each advective time step of a multilevel, limited-area semi-Lagrangian model. The distinctive feature of the method is that it is composed of a cascade of one-dimensional interpolations of entire fields of data through a sequence of intermediate grids. These intermediate grids are formed as hybrid combinations of the standard model grid coordinates, which, together with the Lagrangian coordinates, are delineated by the origins of the trajectories that characterize the semi-Lagrangian method. When applied at Nth-order accuracy, the cascade method requires only O(N) operations compared with O(N3) for the conventional three-dimensional interpolation methods, making the adoption of high-order schemes attractive. The technique was tested on a large number (100) of 48-h forecasts and was found to be as accurate as the conventional interpolation procedures based on point-by-point Cartesian products of one-dimensional inte.
DWARF-NOVA OUTBURSTS

Outburst mechanisms of dwarf novae are discussed. There is a rich variety in outburst behaviors of non-magnetic cataclysmic variable stars, starting from non-outbursting nova-like stars to various sub-classes of dwarf novae (i.e., U Gem-type, Z Cam-type, and SU UMa-type). A unification model for dwarf nova outbursts is proposed within the basic framework of the disk instability model in which two different intrinsic instabilities (i.e., the thermal instability and the tidal instability) within accretion disks play an essential role. Non-magnetic cataclysmic variables are classified into four regions in the orbital-period versus mass-transfer-rate diagram, showing different combinations of stability behavior for the two intrinsic instabilities in accretion disks, and their different outburst behaviors are basically understood in this diagram. We discuss several problems concerning the thermal limit-cycle instability model for dwarf novae above the period gap. We then discuss the thermal-tidal instability model for SU UMa stars, dwarf novae below the period gap, in which the coupling of the two intrinsic instabilities in the accretion disk plays a unique role. In particular, a rich variety of outburst behaviors of cataclysmic variables below the period gap (i.e., starting from "permanent superhumpers", to Z Cam-like SU UMa stars, "ER UMa stars", to ordinary SU UMa stars, and finally to WZ Sge stars) is understood by the thermal-tidal instability model.
Observation of spectral gain narrowing in a high-order harmonic seeded soft-x-ray amplifier

We report an observation of spectral gain narrowing of a high-order harmonic amplified by a soft-x-ray optical-field-ionized plasma. The temporal coherence and spectral linewidth of both the seeded and unseeded soft-x-ray lasers were experimentally measured using a varying-path-difference interferometer. The results showed that the high-order harmonic is subject to a strong spectral narrowing during its propagation in the plasma amplifier without rebroadening at saturation. This is in good agreement with a radiative transfer calculation including gain narrowing and saturation rebroadening.
Characteristics of Ultra-Low q Plasmas in the OHTE Device

The characteristics of plasmas with the safety factor q between that of tokamaks and that of reversed field pinches were studied on the OHTE device, with toroidal fields of up to 3.9 kG and plasma currents of up to 140 kA. Plasmas in this regime (0 < q < 1) are called ultra-low q plasmas. The discharges are globally stable and last much longer than the resistive decay time of the current. A unique feature of most discharges is a series of plateaus in the current (or equivalently q) as the current decreases in a ‘staircase’ fashion. The plateau q is related to the major rational ratios (1/4, 1/3, 1/2, 1, etc.), suggesting plasma self-organization. Profile measurements show that the q-profile is somewhat different from those of the Taylor relaxed states. The soft X-ray temperature measurement indicates that the plasma has burned through the radiation barrier.
EXCHANGE EFFECT OF A HOT FERMIONIC PLASMA CONFINED IN AN ARBITRARY POTENTIAL BARRIER. I: THE WEAK MAGNETIC FIELD LIMIT

The author develops a general formulation for the free energy of a hot Fermionic plasma confined in an arbitrary smooth potential barrier and a weak magnetic field. The well-known Wigner-Kirkwood expansion turns out to be powerful computational technique in the investigation. The explicit formulae obtained enable one to calculate exchange and confining effects on various physical properties of such systems. As an example, they are applied to calculations of exchange and confining corrections to the diamagnetic susceptibility and the specific heat. The author also constructs some examples by simple choices of the confining potential barrier.
Geometrical derivation of Lagrange’s equations for a system of particles

A concise but general derivation of Lagrange’s equations is given for a system of finitely many particles subject to holonomic and nonholonomic constraints. Based directly on Newton’s second law, it takes advantage of an inertia‐based metric to obtain a geometrically transparent statement of Lagrange’s equations in configuration space. Illustrative examples are included.
Parents and Peers: Gender Stereotypes in the Field of Study

Gender segregation in the field of study is still a pervasive phenomenon in many countries. In this paper, we highlight the crucial role of parents and peers in adolescents’ decision making on their educational choices, leading to a mismatch of talents. We design a lab-in-the-field experiment that exposes 2,500 middle school students in Italy to different information treatments before they choose between a female-typed task (literature) and a male-typed task (math). We find that students choose a more gender-stereotypical subject (girls choose more literature and boys choose more math) when they are induced to think about the recommendation of same-gender parents. The effect is driven by girls who expect literature as a recommendation from their mothers and boys who expect math as a recommendation from their fathers. The field choice of male and female students is not affected when they expect their peers to observe their decision. However, we show that girls shy away from math to avoid interactions in male-dominated contexts.
Challenges Facing BOT Strategy Adoption in the Palestinian Water and Energy Sectors

Global experiences prove that public-private partnership strategies and build-operate-transfer (BOT)in particular, can provide a reliable alternative funding sources, particularly for developing countries with budget deficits that cannot meet public needs. It is observed that, though many best practices were evolved, but yet a lot should be done to develop an integral system to that. Conclusions of previous research reveals that, rational flexibility from all parties will enable enforcing collaborative solutions to BOT risks. To adopt such strategy in Palestine, this requires accurate identification and consideration of general challenges and those specific to Palestine. A questionnaire comprising 55 challenges classified into six categories was administered to key actor-respondents who rated the influence of those challenges. SPSS analysis shows that political and legal challenges were strongest considerations. To build a model of best practices to BOT adoption, we recommend establishing a public corporation to finance BOT projects and further advise the Palestinian government to establish a BOT unit attached to the prime ministers’ office to manage, handle and develop the implementation of this such a strategy. However, such efforts may not succeed if restrictions enforced by the long-term belligerent Israeli occupation persists; these undoubtedly constitute the largest obstacle to Palestine’s development.
Premature ventricular contraction (PVC) classifications by probabilistic neural network (PNN) using the optimal mother wavelets

This paper presented our attempt to determine the reliability and accuracy of classifying Premature Ventricular Contraction (PVC) and several other arrhythmias using optimal mother wavelets and feature dataset obtained from our previous study in [1]. The proposed classifier is Probabilistic Neural Network (PNN) with less-overlapping data set between training and testing. In our previous study of [1], we found that the most outperformed wavelets among the 35 mother wavelets tested are "haar", "db3" and "sym3" with overall average accuracy percentage of 85.47% for "haar" and 84.13% both for "db3" and "sym3". The result is slightly lower (<90%) than expected, as we found that the statistical indices of the wavelet coefficients used might not be good features; instead, using the whole coefficients may give higher accuracy. However, the calculation of peak-to-peak ratio proves to be encouraging as it provides convenient differentiator and is believed to be one of the factors that contribute to high accuracy. Addition to that, the selection of inverted R peak for PVC that do not have R peak also plays important role. It is observed that the accuracy of PVC with no R peak (inverted R peak detection) is to be 91.28% for "haar", 92.19% for "db3" and 92.19% for "sym3"
Empirical pseudopotential calculations of the band structure and ballistic conductance of strained [001], [110], and [111] silicon nanowires

The electronic band structure of hydrogen passivated, square cross-section, uniaxially strained [001], [110], and [111] silicon nanowires (Si NWs) has been calculated using nonlocal empirical pseudopotentials calibrated to yield the correct work function and benchmarked against first-principles calculations. We present results regarding the dependence and direct/indirect nature of the bandgap on wire diameter and uniaxial strain as well as the ballistic conductance and effective mass. As a result of practical interest, we have found that the largest ballistic electron conductance occurs for compressively strained large-diameter [001] wires while the smallest transport electron effective mass is found for larger-diameter [110] wires under tensile stress.
Competition of various spin states of LaCoO 3

The spin-state transition in perovskite ${\mathrm{LaCoO}}_{3}$ has been a controversial topic ever since its discovery. To obtain a better physical understanding of its origin we have studied various magnetically ordered states of an enlarged double cell, including the low-spin state, intermediate-spin state, high-spin state, as well as all combinations among these three states. The calculations were done within the unrestricted Hartree-Fock approximation and the real-space recursion method. The density of states and stability of various states are analyzed as functions of model parameters. Our results show that the ground state of the system depends on the competition between the crystal-field splitting $\mathrm{Dq}$ and the Hund's coupling $j$. For a fixed $j$, the ground state of the system changes from the low-spin state to the low-spin high-spin ordered state (LS-HS) and finally to the high-spin high-spin antiferromagnetically ordered state as $\mathrm{Dq}$ is weakened. Our study suggests that the spin-state transition at 90 K probably takes place from the low-spin state to the LS-HS ordered state.
Characteristics of Surface Particle Motion of Coiled Waveguide Caused by Flexural Ultrasonic Waves

A traveling wave miniature ultrasonic motor has been developed using a helical coiled waveguide as a stator, and it has been applied to an intravascular ultrasound (IVUS) probe. In this motor, the elliptical motion of the surface particle due to flexural ultrasonic waves drives the rotor which can be placed inside or outside adjacent to the stator via frictional force. However, the fact that the rotational direction of the outer rotor is the reverse of that of the inner rotor at low frequencies of the flexural wave has not been clarified theoretically. In this study, the surface particle motion is investigated through finite element method (FEM) simulations, and the basis of the rotational directions is clarified.
Averaged equations for inviscid disperse two-phase flow

Averaged equations governing the motion of equal rigid spheres suspended in a potential flow are derived from the equation for the probability distribution. A distinctive feature of this work is the derivation of the disperse-phase momentum equation by averaging the particle equation of motion directly, rather than the microscopic equation for the particle material. This approach is more flexible than the usual one and leads to a simpler and more fundamental description of the particle phase. The model is closed in a systematic way (i.e. with no ad hoc assumptions) in the dilute limit and in the linear limit. One of the closure quantities is related to the difference between the gradient of the average pressure and the average pressure gradient, a well-known problem in the widely used two-fluid engineering models. The present result for this quantity leads to the introduction of a modified added mass coefficient (related to Wallis's ‘exertia’) that remains very nearly constant with changes in the volume fraction and densities of the phases. Statistics of this coefficient are provided and exhibit a rather strong variability of up to 20% among different numerical simulations. A detailed comparison of the present results with those of other investigators is given in § 10. As a further illustration of the flexibility of the techniques developed in the paper, in Appendix C they are applied to the calculation of the so-called ‘particle stress’ tensor. This derivation is considerably simpler than others available in the literature.
Rapid detection of pesticide residue in apple based on Raman spectroscopy

The potential of Raman spectroscopy in the analysis of low concentration organic contaminants on apples' surface was evidenced in this study. Chlorpyrifos, an organophosphorus pesticide, was used as a probe for this purpose. The characteristic peaks of fingerprints of pesticide on an aluminum substrate and apple fruit cuticle without pesticide residue were acquired first. Then a concentration range of chlorpyrifos (commercial products at 40%) solutions were made using deionised and distilled water. Single 100 μL droplets of the chlorpyrifos solutions were placed gently on apple fruit cuticles and left to dry before analysis. Through comparative analysis of the Raman spectra data collected, 341, 632 and 1237cm-1 were identified to detect the chlorpyrifos pesticide residue on apple surface. Based on the relationship between the Raman intensity of the most prominent peak at around 632cm-1 and the pesticide concentrations, the limit of detection of ordinary Raman spectrum for chlorpyrifos was estimated to be 48ppm.
Almost Sure Stabilizability and Riccati's Equation of Linear Systems with Random Parameters

Linear systems with stationary time-varying parameters are considered. The notions of almost sure stabilizability and almost sure detectability are explored. Under these properties the asymptotic behavior of the associated Riccati equation is described. In particular, the stability of the Kalman filter and the convergence of linear observers are proved.
Modified cauchy kernels and functional calculus for operators on Banach space

Abstract In Banach space operators with a bounded H∞ functional calculus, Cowling et al. provide some necessary and sufficient conditions for a type-ω operator to have a bounded H∞ functional calculus. We provide an alternate development of some of their ideas using a modified Cauchy kernel which is L1 with respect to the measure ]dz]/]z]. The method is direct and has the advantage that no transforms of the functions are necessary.
Ratios of Normal Variables

This article extends and amplifies on results from a paper of over forty years ago. It provides software for evaluating the density and distribution functions of the ratio z/w for any two jointly normal variates z,w, and provides details on methods for transforming a general ratio z/w into a standard form, (a+x)/(b+y) , with x and y independent standard normal and a, b non-negative constants. It discusses handling general ratios when, in theory, none of the moments exist yet practical considerations suggest there should be approximations whose adequacy can be verified by means of the included software. These approximations show that many of the ratios of normal variates encountered in practice can themselves be taken as normally distributed. A practical rule is developed: If a
Switching characteristics and maximum repetitive frequency of InGaAsP/InP bistable injection lasers

Switching characteristics of nonuniformly pumped InGaAsP/InP buried-heterostructure bistable lasers are investigated both experimentally and theoretically. The automatic turn-on phenomenon, which is a random process, was observed. For repetitive operation, turn-on delay time and the necessary duration of the switch-off pulse practically limited the maximum repetitive frequency. For switch-on, triggering the saturable absorption region is more effective. For reducing the minimum switch-off pulse width, either higher doping of reverse biasing at the absorption region is recommended. The tradeoff of OFF pulse width with threshold current, and stable operation are discussed. With some improvements in device parameters, bistable operation at a repetitive frequency over 1 GHz is expected. >
Resonant frequencies of arbitrarily shaped microstrip patch antennas using two-dimensional circuit model

Two-dimensional circuit is used to determine the resonant frequencies of the arbitrarily shaped, single-layer microstrip patch antennas. This circuit is based on the long transmission line model in the frequency domain. Derivation, analysis, and treatment of boundaries are given. Simple matrix form is obtained and the problem is reduced to an eigenvalue problem which is solved to get the required solution. The resonant frequencies of the resulting circuit are the required resonant frequencies of the patch antenna. Numerical results are given and are compared with the available analytical and experimental results reported by others.
Coherent acoustic phonons in hexagonal manganite LuMnO3

We have observed coherent acoustic phonons in the hexagonal manganite LuMnO3 using two-color femtosecond optical pump-probe spectroscopy. The dependence of the oscillatory component of the photoinduced reflectivity on the probe wavelength and incident angle is consistent with a propagating strain pulse. Moreover, the frequency, dephasing, and phase of the oscillation are found to be temperature dependent. In particular, a large phase shift occurs in the vicinity of the Neel temperature (TN), which we relate to the temperature-dependent on-site Mn d–d transition that is coupled to antiferromagnetic ordering, as recently observed in optical conductivity measurements.
Effect of a parallel electric field on the whistler mode instability in the magnetosphere

A dispersion relation for the whistler mode wave propagation in an anisotropic warm magnetoplasma in the presence of a weak parallel electrostatic field has been derived from linearized coupled Boltzmann-Maxwell equations with collision frequency independent of particle velocity. An expression for the growth rate has been derived in the presence of an electric field and for small temperature anisotropy (A<1) for the whistler mode wave. Under suitable approximation we recover the earlier known results. The modifications introduced in the growth rate by the electric field and temperature anisotropy have been discussed using observed plasma parameters at 6.6 RE. It is observed that growth (damping) of whistler mode waves is possible when the wave vector is parallel (antiparallel) to the static electric field. The effect of the electric field is more pronounced at low frequency (higher wave number) wave spectrum.
Acoustical effect of progressive undercutting of percussive aluminum bars

Standard vibraphone bars consist of aluminum beams which are traditionally tuned with an arched undercut, for the purpose of aligning the musical overtones harmonically. The acoustical effect of various progressions of undercuts on aluminum bars was studied using both an aluminum bar and a finite element computer model. The spectral signature of the aluminum bar was examined with a spectrum analyzer, and the corresponding eigenmodes were imaged with an electronic speckle pattern interferometer. These methods were used to analyze the changes in natural frequencies of the bar as matter was removed from various locations. Additionally, the aural character of each cut was captured with an audio recording, and the fundamental tone was normalized over all recordings to make possible a subjective comparison of the timbral differences of differently cut bars.
Analysis of delay variability at isolated signalized intersections

On urban arterials, travel time variability is largely dependent on the variability in the delays vehicles experience at signalized intersections. The interpretation of delay evolvement at intersections will give a comprehensive insight into arterial travel time variability and provide more possibilities for travel time estimation. Accordingly, an analytical model is proposed to study delay variability at isolated, fixed-time controlled intersections. Classic cumulative curves are utilized to derive average delay (per cycle) formulas by assuming a deterministic overflow queue. Then, an analogy with the Markov chain process is made to clarify the mechanism of stochastic delays and overflow queues at signalized intersections. It was found that, in undersaturated cases, the shape of the delay distribution changes very little over time, whereas for saturated and oversaturated cases the delay distribution is time-dependent and becomes flatter with an increasing number of cycles. The analysis of arrival distributions, e.g., Poisson and binomial, produces the conclusion that the variability of arrivals has a significant effect on delay estimates in both undersaturated and oversaturated conditions. A larger variance of arrival flow results in a larger variance of delay distribution. All of these analyses can help road authorities to gain insights into arterial travel time variability.
Correction to Interferometric Measurements of Absolute Gravity Arising from the Finite Speed of Light

A general formula for the correction arising from the finite speed of light is derived for interferometric absolute gravimetry and is applied to some gravimeters. To attain an accuracy of a few μGal (1 μGal = 10-8 m/s2) level in gravimeters using the direct free-fall method the initial velocity should be carefully taken into account, but this correction is not necessary in ones which use the symmetric rise-and-fall method.
A Study of General Education Astronomy Students' Understandings of Cosmology. Part I. Development and Validation of Four Conceptual Cosmology Surveys

This is the first in a series of five articles describing a national study of general education astronomy students’ conceptual and reasoning difficulties with cosmology. In this paper, we describe the process by which we designed four new surveys to assess general education astronomy students’ conceptual cosmology knowledge. These surveys focused on the expansion and evolution of the universe, the Big Bang, and the evidence for dark matter in spiral galaxies. We also present qualitative evidence for the validity of these surveys.