Miracle-dz/UniFAR-FTUs huggingface dataset:
Evaluation of Medium-Range Forecasts for Hurricane Sandy

AbstractOn 30 October 2012 Hurricane Sandy made landfall on the U.S. East Coast with a devastating impact. Here the performance of the ECMWF forecasts (both high resolution and ensemble) are evaluated together with ensemble forecasts from other numerical weather prediction centers, available from The Observing System Research and Predictability Experiment (THORPEX) Interactive Grand Global Ensemble (TIGGE) archive. The sensitivity to sea surface temperature (SST) and model resolution for the ECMWF forecasts are explored. The results show that the ECMWF forecasts provided a clear indication of the landfall from 7 days in advance. Comparing ensemble forecasts from different centers, the authors find the ensemble forecasts from ECMWF to be the most consistent in the forecast of the landfall of Sandy on the New Jersey coastline. The impact of the warm SST anomaly off the U.S. East Coast is investigated by running sensitivity experiments with climatological SST instead of persisting the SST anomaly from the an.
Mathematics majors’ beliefs about proof reading

We argue that mathematics majors learn little from the proofs they read in their advanced mathematics courses because these students and their teachers have different perceptions about students’ responsibilities when reading a mathematical proof. We used observations from a qualitative study where 28 undergraduates were observed evaluating mathematical arguments to hypothesize that mathematics majors hold four specific unproductive beliefs about proof reading. We then conducted a survey about these beliefs with 175 mathematics majors and 83 mathematicians. We found that mathematics majors were more likely to believe that when reading a good proof, they are not expected to construct justifications and diagrams, they can understand most proofs they read within 15 minutes, and understanding a proof is tantamount to being able to justify each step in the proof.
Possible existence of multiple chiral doublets in (106)Rh

Adiabatic and configuration-fixed constrained triaxial relativistic mean field (RMF) approaches are developed for the first time. A new phenomenon, the existence of multiple chiral doublets (M{chi}D), i.e., more than one pair of chiral doublet bands in one single nucleus, is suggested for {sup 106}Rh based on the triaxial deformations and their corresponding proton and neutron configurations.
Detailed Hard X-Ray Measurements of Nuclear Emission from the Seyfert2 Galaxy NGC4388 with Suzaku

We report on a Suzaku observation of the nearby Seyfert 2 galaxy NGC 4388. The overall spectrum is well described by the combination of strongly absorbed power-law plus thin thermal plasma emission, as well as previous observations. Thanks to well-calibrated instruments and a low background level, Suzaku measured the broad-band X-ray spectra more precisely than ever, and enabled us to probe the physical structure of the nuclear region. In addition, a time variability having a factor of 1.5 with a half-day time scale was found up to above 10 keV. The center energy and the Kˇ/K ratio of the narrow Fe-K line, together with less time variability, indicate that the fluorescent material is far from the black hole. A spectral hump around the 30–40 keV band, together with a Compton shoulder of the Fe-K line, requires a significant contribution of the reflection component. This is also consistent with a smaller amplitude of time variability in a higher energy band. A large contribution of the reflection component was not observed by the CGRO/OSSE and BeppoSAX, suggesting that NGC 4388 had been in a higher flux state, and that Suzaku observed its light echo. A He-like Fe-K absorption line was also detected, indicating the existence of highly ionized plasma.
Data analysis of multi-laser standoff spectral identification of chemical and biological compounds

With the availability of tunable broadband coherent sources that emit mid-infrared radiation with well-defined beam characteristics, spectroscopies that were traditionally not practical for standoff detection1 or for development of miniaturized infrared detectors2, 3 have renewed interest. While obtaining compositional information for objects from a distance remains a major challenge in chemical and biological sensing, recently we demonstrated that capitalizing on mid-infrared excitation of target molecules by using quantum cascade lasers and invoking a pump probe scheme can provide spectral fingerprints of substances from a variable standoff distance.3 However, the standoff data is typically associated with random fluctuations that can corrupt the fine spectral features and useful data. To process the data from standoff experiments toward better recognition we consider and apply two types of denoising techniques, namely, spectral analysis and Karhunen-Loeve Transform (KLT). Using these techniques, infrared spectral data have been effectively improved. The result of the analysis illustrates that KLT can be adapted as a powerful data denoising tool for the presented pump-probe infrared standoff spectroscopy.
Vibrationally resolved photoionization of the 1σg and 1σu shells of N2 molecule

Theoretical and experimental study of vibrationally resolved partial photoionization cross sections and angular asymmetry parameter β for the 1σg and 1σu shells of N2 molecule in the region of the σ* shape resonance is reported. The measurements were made at the synchrotron radiation facility SPring-8 in Japan. The calculations in the random phase approximation have been performed using the relaxed core Hartree–Fock wavefunctions with the fractional charge of the ion core equal to 0.7. With its help, the role of interchannel coupling between the closely spaced 1σg and 1σu shells was studied. The experiment demonstrates the existence of a correlational maximum in the 1σu shell photoionization cross section induced by the σ* shape resonance in the 1σg shell. This maximum reveals itself even more clearly in the angular asymmetry parameter β for the v′ = 0 and v′ = 1 vibrational states of the ion. The calculation in the random phase approximation gives a consistent interpretation of the experimental data.
Molecular‐beam‐epitaxial growth and magnetic properties of (111)Pt/Co/Ag, Pt/Co, and Ag/Co/Pt superlattices

The structural and the magnetic properties of (111)Pt/Co/Ag, Pt/Co, and Ag/Co/Pt superlattices (SLs) were studied. The samples were grown at 373 K on Ag buffer layers preformed on 7×7‐(111)Si substrates by molecular‐beam epitaxy. Reflection high‐energy electron diffraction indicated that in‐plane lattice constants of Co, Pt, and Ag layers changed continuously during layer growth in Pt/Co/Ag SLs with thin Co layers and Pt/Co SLs. The effective magnetic anisotropy energy Keff of a Pt/Co/Ag SL was similar to Keff, an average of Keff values of a Pt/Co and an Ag/Co SL with the same Co layer thicknesses. This suggests that the origins of perpendicular magnetic anisotropy in the Pt/Co system are different from those in the Au/Co system investigated earlier, in which the difference between the Au/Co and Au/Co/Ag SLs is small in Keff value.
Retrieval-induced forgetting of arithmetic facts but not rules

Retrieval of a multiplication fact (2×6 =12) can disrupt retrieval of its addition counterpart (2+6=8). We investigated whether this retrieval-induced forgetting effect applies to rule-governed arithmetic facts (i.e., 0×N=0, 1×N=N). Participants (n=40) practised rule-governed multiplication problems (e.g., 1×4, 0×5) and multiplication facts (e.g., 2×3, 4×5) for four blocks and then were tested on the addition counterparts (e.g., 1+4, 0+5, 2+3, 4+5) and control additions. Increased addition response times and errors relative to controls occurred only for problems corresponding to multiplication facts, with no problem-specific effects on addition counterparts of rule-governed multiplications. In contrast, the rule-governed 0+N problems provided evidence of generalisation of practice across items, whereas the fact-based 1+N problems did not. These findings support the theory that elementary arithmetic rules and facts involve distinct memory processes, and confirmed that previous, seemly inconsistent findings of RIF in arithmetic owed to the inclusion or exclusion of rule-governed problems.
Condensation Measurement of Horizontal Cocurrent Steam/Water Flow

Condensation of steam on a subcooled water layer was studied in a cocurrent horizontal channel at atmospheric pressure. The heat transfer coefficients were found to vary from 1.3 kWS/m/sup 20/C to 20 kW/m/sup 20/C, depending on whether the liquid interface was smooth or wavy, increased with increasing steam flow rates and water flow rates. For all cases, 50 to 90 percent of the steam condensed within 1.2 m from the entrance. The average Nusselt numbers were correlated with average steam and water Reynolds numbers an average liquid Prandtl numbers, for both smooth and wavy interface flows. Finally, a correlation of the average heat transfer coefficient and condensation rate for wavy interface flow was obtained as a function of inlet conditions and distance downstream.
A Search for Wide Binaries at the North Galactic Pole using Precise Radial Velocities

Les observations, realisees avec le velocimetre digital CfA, de 247 etoiles centrees sur la region SA 57 au pole nord galactique, complet pour les etoiles de type avance plus brillantes que V=12, sont presentees. Les vitesses radiales sont tabulees. Une estimation des distances et une redefinition des types spectraux sont realisees. La presence de binaires detachees parmi les paires de separation angulaire comprise entre 1 et 600 secondes d'arc est analysee
Sensitivity analysis of nonlinear programs and differentiability properties of metric projections

This paper is concerned with a study of differentiability properties of the optimal value function and an associated optimal solution of a parametrized nonlinear program. Second order analysis is presented essentially under the Mangasarian-Fromovitz constraint qualification when the corresponding vector of Lagrange multipliers is not necessarily unique. It is shown that under certain regularity conditions the optimal value function possesses second order directional derivatives and the optimal solution mapping is directionally differentiable. The results obtained are applied to an investigation of metric projections in finite-dimensional spaces.
Lyapunov type inequalities for a second order differential equation with a damping term

For a second order differential equation with a damping term, we establish some new inequalities of Lyapunov type. These inequalities give implicit lower bounds on the distance between zeros of a nontrivial solution and also lower bounds for the spacing between zeros of a solution and/or its derivative. We also obtain a lower bound for the first eigenvalue of a boundary value problem. The main results are proved by applying the Holder inequality and some generalizations of Opial and Wirtinger type inequalities. The results yield conditions for disfocality and disconjugacy. An example is considered to illustrate the main results.
Flow past an impulsively started circular cylinder

An accurate method is described for integrating the Navier-Stokes equations numerically for the time-dependent flow past an impulsively started circular cylinder. Results of integrations over the range of Reynolds numbers, based on the diameter of the cylinder, from 5 to ∞ are presented and compared with previous numerical, theoretical and experimental results. In particular, the growth of the length of the separated wake behind the cylinder has been calculated for R = 40, 100 and 200 and is found to be in very good agreement with the results of recent experimental measurements. The calculated pressure distribution over the surface of the cylinder for R = 500 is also found to be in reasonable agreement with experimental measurements for the case R = 560. For Reynolds numbers up to 100 the equations were integrated until most of the features of the flow showed a close approximation to steady-state conditions. The results obtained are in good agreement with previous calculations of the steady flow past a circular cylinder. For R > 100 the integrations were continued until the implicit method of integration broke down by reason of its failure to converge. A secondary vortex appeared on the surface of the cylinder in the case R = 500, but for higher Reynolds numbers, including the case R = ∞, the procedure broke down before the appearance of a secondary vortex. In all cases the flow was assumed to remain symmetrical.
Modelling global temperature trends using cointegration and smooth transitions

We analyse annual northern and southern hemisphere temperature data from 1856 to 1998 using models that contain either stochastic linear trends or deterministic non-linear trends. We find that changes in southern hemisphere temperatures lead to changes in northern hemisphere temperatures, with no evidence of feedback, in both types of model. Where the models differ is that the assumption of stochastic linear trends leads to a common trend with constant growth throughout the sample period, whereas with deterministic non-linear trends there are divergent trend growth paths in the two hemispheres after the early part of the twentieth century.
Predictions for statistical properties of forming spheroidal galaxies

We show that the features of the recent astrophysically motivated model by Granato et al. are fully consistent with the available statistical measurements of galaxies at (sub)millimetre wavelengths. We quantitatively predict the impact of this scenario on near-future cosmological observations dealing with spatial and flux statistical distribution of (sub)millimetre galaxies. We show that the expected angular correlation function of spheroids is compatible with available data. We compute the expected power spectrum of fluctuations due to clustering at the frequencies of the High Frequency Instrument (HFI) on ESA's Planck satellite: the clustering signal is found to be detectable in regions of low interstellar dust emission. A further distinctive prediction of the adopted model is a remarkably high fraction of gravitationally lensed sources at bright millimetre/submillimetre fluxes. In fact, since most spheroids burn at redshift z≃ 2–3 according to the adopted model, gravitational lensing amplifies a significant number of high-z forming spheroidal galaxies, which will be detectable by large-area, shallow surveys at millimetre/submillimetre wavelengths, such as those carried out by Planck/HFI. Allowing for other source populations, we find that the fraction of gravitationally lensed millimetre/submillimetre sources at fluxes >100 mJy is expected to be up to ≃40 per cent.
Vortex-In-Cell and Probability Density Function Approach for a Passive Scalar Field in a Mixing Layer

A Reynolds-averaged simulation based on the vortex-in-cell (VIC) and the transport equation for the probability density function (PDF) of a scalar has been developed to predict the passive scalar field in a two-dimensional spatially growing mixing layer. The VIC computes the instantaneous velocity and vorticity fields. Then the mean-flow properties, i.e. the mean velocity, the root-mean-square (rms) longitudinal and lateral velocity fluctuations, the Reynolds shear stress, and the rms vorticity fluctuations are computed and used as input to the PDF equation. The PDF transport equation is solved using the Monte Carlo technique. The convection term uses the mean velocities from the VIC. The turbulent diffusion term is modeled using the gradient transport model, in which the eddy diffusivity, computed via the Boussinesq's postulate, uses the Reynolds shear stress and gradients of mean velocities from the VIC. The molecular mixing term is closed by the modified Curl model. The computational results were compared with two-dimensional experimental results for passive scalar. The predicted turbulent flow characteristics, i.e. mean velocity and rms longitudinal fluctuations in the self-preserving region, show good agreement with the experimental measurements. The profiles of the mean scalar and the rms scalar fluctuations are also in reasonable agreement with the experimental measurements. Comparison between the mean scalar and the mean velocity profiles shows that the scalar mixing region extends further into the free stream than does the momentum mixing region, indicating enhanced transport of scalar over momentum. The rms scalar profiles exhibit an asymmetry relative to the concentration centerline, and indicate that the fluid on the high-speed side mixes at a faster rate than the fluid on the low-speed side. The asymmetry is due to the asymmetry in the mixing frequency cross-stream profiles. Also, the PDFs have peaks biased toward the high-speed side.
Steady inclined flows of granular-fluid mixtures

We extend a recent theory for steady uniform gravity-driven flow of a highly concentrated granular-fluid mixture over an erodible bed between frictional sidewalls. We first include angles of inclination greater than the angle of repose of the particles; then, we introduce a boundary condition for flow over a rigid bumpy bed. We compare the predictions of the resulting theory with the volume flow rates, depths and angles of inclination measured in the experiments on dry and variously saturated flows over rigid and erodible boundaries. Finally, we employ the resulting theory, with the assumption that the flow is shallow, to solve, in an approximate way, for the variation of height and average velocities along a steady non-uniform inclined flow of a granular-fluid mixture that moves over a rigid bumpy bed. The solutions exhibit features of the flow seen in the experiments – for example, a dry bulbous snout in advance of the fluid, whose length increases with increasing number of the particles and that disappears with increasing velocity – for which satisfactory explanations were lacking.
Ultraviolet InGaN and GaN Single-Quantum-Well-Structure Light-Emitting Diodes Grown on Epitaxially Laterally Overgrown GaN Substrates

Ultraviolet (UV) InGaN and GaN single-quantum-well-structure light-emitting diodes (LEDs) were grown on epitaxially laterally overgrown GaN (ELOG) and sapphire substrates. When the emission wavelength of UV InGaN LEDs was shorter than 380 nm, the external quantum efficiency (EQE) of the LED on ELOG was much higher than that on sapphire only under high-current operation. At low-current operation, both LEDs had the same EQE. When the active layer was GaN, EQE of the LED on sapphire was much lower than that on ELOG even under low-and high-current operations, due to the lack of localized energy states formed by alloy composition fluctuations. When the emission wavelengths were in the blue and green regions, EQE was almost the same between LEDs on both ELOG and sapphire due to a large number of deep localized energy states formed by large alloy composition fluctuations. The localized energy states are responsible for the high efficiency of InGaN-based LEDs in spite of a large number of dislocations.
ALMOST SURE BOUNDEDNESS OF RANDOMLY SAMPLED SYSTEMS

This paper discusses the almost sure boundedness of linear and nonlinear randomly sampled systems. It is shown that if an autonomous linear randomly sampled system exhibits almost sure asymptotic stability, then the system is almost surely bounded input–bounded output. Moreover, for a bounded input, the second moment of the output remains bounded and this bound is easily computable.It is also found that linear or nonlinear systems which are almost surely asymptotically stable for a null input remain almost surely bounded when the input consists of an uncorrelated noise with finite variance.
Cross-identifications and astro-photometric comparisons of the ICRF with recent catalogs of quasars

The ICRF represents the most accurate astrometric catalog that is the primary reference frame adopted by the IAU General Assembly at Kyoto in 1997. Despite its importance, an exhaustive study of both the sky coverage and the physical properties of the extragalactic sources representing the ICRF is lacking. The object of the present paper is to extract some information concerning these sources and cross-identify them with the data gathered by Veron-Cetty & Veron (2003, A&A, 412, 399), which is the largest compilation of various catalogs of quasars. After this cross-identification of the sources, we carry out a study of some general features of the ICRF concerning the visual magnitudes, the redshifts, and the flux at radio wavelengths.
Simulation of Combustion Instabilities in Liquid Rocket Engines with Acoustic Perturbation Equations

The authors present a new method for predicting combustion instabilities in liquid rocket engines. This method is based on the solution of the linearized governing equations for a three-dimensional combustor geometry in the time domain. The aim of this paper is to show the general feasibility of the approach and to explain the general behavior of the model. The computational domain comprises the combustion chamber itself and the convergent part of the nozzle. The heat release is included via a source term in the linearized energy equation. In the example of the European Aestus engine, it is shown that the model is able to predict the different oscillation modes without any preliminary assumptions about them. An analysis of the influence of the nozzle illustrates that its behavior is automatically included in the approach by design. In comparison to the solution of the full Navier―Stokes equations, the method has the advantage of a much lower numerical cost.
Calculating total acoustic power output using modal radiation efficiencies

Over the last 20 years a great deal of work has been devoted to obtaining expressions describing the radiation efficiencies of structural mode shape functions, in an effort to qualify the radiation characteristics of the structure. These modal radiation efficiencies cannot, however, be used directly in the calculation of total radiated acoustic power, as this latter quantity is not equal to the sum of the acoustic power radiated by each mode vibrating on its own. This paper addressed the problem of using modal radiation efficiencies to calculate the total acoustic power output of a simply supported rectangular panel. It is shown that there is an extremely simple way to use modal radiation efficiencies to calculate the total acoustic power output of the panel, the accuracy of which is limited only by the same low‐frequency constraints placed upon the accuracy of the modal radiation efficiencies themselves.
Two Stage Least Absolute Deviations Estimators

In this paper the method of least absolute deviations is applied to the estimation of the parameters of a structural equation in the simultaneous equations model. A class of estimators called two stage least absolute deviations estimators is defined, their asymptotic properties are derived, and the problem of finding the optimal member of the class is considered. IN THIS PAPER WE APPLY the method of least absolute deviations to the estimation of the parameters of a structural equation in the simultaneous equations model. We define a class of estimators called two stage least absolute deviations estimators (2SLAD) and derive their asymptotic properties. They are so named as their relationship to the two stage least squares estimator (2SLS) is analogous to the relationship of the least absolute deviations estimator (LAD) to the least squares estimator (LS) in the standard regression model. The LAD estimation has been extensively studied in the context of the standard regression model and its usefulness is universally recognized. In this paper we show that the advantage of 2SLAD over 2SLS in the simultaneous equations model can be as great as that of LAD over LS in the standard regression model, if 2SLAD is properly defined. This last clause is very important, since the results of this paper indicate that the LAD analogue of 2SLS that has been considered before in the literature is not an appropriate method.