Miracle-dz/UniFAR-FTUs huggingface dataset:
Assessment of forecasts and forecast uncertainty using feneralized linear regression models for time series count data

This paper evaluates a prediction methodology for forecasting non-Gaussian time series count data using quasi-likelihood regression models. A detailed simulation study is used to assess the accuracy of forecasts from the quasi-likelihood predictor, and to study the effect of several different specifications of the variance–covariance matrix in the quasi-likelihood approach. Effects due to the strength of the autocorrelation and overdispersion on the accuracy of the forecasts are also investigated. Forecasts and forecast uncertainty obtained using the quasi-likelihood predictor are also compared to those obtained using the traditional best linear unbiased predictor (BLUP). Results from this investigation show that the quasi-likelihood predictors give fairly accurate results in a variety of situations and give more accurate forecasts than the BLUP, regardless of the magnitude of the overdispersion, the strength of the autocorrelation, or the nature of the mean function. These results also show that the measure of forecast error associated with the quasi-likelihood predictor more realistically reflects the true variability in the forecast error than that corresponding to the BLUP. Overall, the quasi-likelihood prediction methodology is fairly accurate for forecasting time series count data and may also be an accurate and flexible approach for forecasting other types of non-Gaussian time series data.
Magnetic shielding of Hall thrusters at high discharge voltages

A series of numerical simulations and experiments have been performed to assess the effectiveness of magnetic shielding in a Hall thruster operating in the discharge voltage range of 300–700 V (Isp ≈ 2000–2700 s) at 6 kW, and 800 V (Isp ≈ 3000) at 9 kW. At 6 kW, the magnetic field topology with which highly effective magnetic shielding was previously demonstrated at 300 V has been retained for all other discharge voltages; only the magnitude of the field has been changed to achieve optimum thruster performance. It is found that magnetic shielding remains highly effective for all discharge voltages studied. This is because the channel is long enough to allow hot electrons near the channel exit to cool significantly upon reaching the anode. Thus, despite the rise of the maximum electron temperature in the channel with discharge voltage, the electrons along the grazing lines of force remain cold enough to eliminate or reduce significantly parallel gradients of the plasma potential near the walls. Computed ma.
Symmetrization and optimal control for elliptic equations

On considere un probleme de commande optimale ou u(x) satisfait −div(H(x)⊇u)=1 dans Ω et H(x) est une commande. On introduit la fonctionnelle J Ω (H)=|Ω| −1 ∫ Ω u(x)dx et on montre que si la fonction distribution de H est fixee, alors J Ω (H) est la plus grande quand Ω est une boule et H est radiale
Fusing E-strings to heterotic strings: E+E→H

E-strings arise from M2 branes suspended between an M5 brane and an M9 plane. In this paper we obtain explicit expressions for the elliptic genus of two E-strings using a series of string dualities. Moreover we show how this can be used to recover the elliptic genus of two $E_8\times E_8$ heterotic strings using the Horava-Witten realization of heterotic strings in M-theory. This involves highly non-trivial identities among Jacobi forms, and is remarkable in light of the fact that E-strings are 'sticky' and form bound states whereas heterotic strings do not form bound states.
An analysis of the energy transfer and the locality of nonlinear interactions in turbulence

Using the results of direct numerical simulations of isotropic turbulence, we compute detailed energy exchanges between different scales of motion and investigate how they contribute to the global quantities such as the energy transfer, the spectral energy flux, and the subgrid-scale dissipation. The scales of motion are defined by decomposing velocity fields using sharp spectral and smooth, tangent hyperbolic filters. The analysis of detailed interactions reveals that individual nonlocal contributions are large but significant cancellations lead to the global quantities asymptotically dominated by the local interactions. Implications of these results for turbulence modeling are discussed.
The Infrared Bright Nuclei in the Mid-Infrared

We present arcsecond angular-resolution mid-IR images of three IR-bright galaxies, NGC 6240, IRAS 0518-25, and the NGC 3690-IC 694 (Arp 299) system, and we compare the sizes of their emission regions in the mid-IR and near-IR. In all these galaxies, most (~75%) of the mid-IR flux, as measured in the IRAS 12 μm observations, is found in our images to be concentrated within the central few hundred parsecs. In the two galaxies which show a single IR source in the nucleus, IRAS 0518-25 and IC 694, the mid-IR emission is more compact than the near-IR. This suggests that the mid-IR source, warm dust heated by an active galactic nucleus or an unresolved starburst, is more compact than the population of cooler, older stars. In the two galaxies which show double sources in the nucleus, the reverse is the case. That is, the mid-IR is more extended than the near-IR. Similar results are obtained for a handful of other galaxies for which we have high-resolution mid-IR data. Thus in our small sample, the double source nuclei contain starbursts which are more extended than the older stars and the single source nuclei do not. Some of the double sources seen in the IR bright galaxies, for example NGC 3690, are probably starbursts in conjunction with a galactic nucleus rather than twin galactic nuclei.
Irradiation-free, columnar defects comprised of self-assembled nanodots and nanorods resulting in strongly enhanced flux-pinning in YBa2Cu3O7−δ films

The development of biaxially textured, second-generation, high-temperature superconducting (HTS) wires is expected to enable most large-scale applications of HTS materials, in particular electric-power applications. For many potential applications, high critical currents in applied magnetic fields are required. It is well known that columnar defects generated by irradiating high-temperature superconducting materials with heavy ions significantly enhance the in-field critical current density. Hence, for over a decade scientists world-wide have sought means to produce such columnar defects in HTS materials without the expense and complexity of ionizing radiation. Using a simple and practically scalable technique, we have succeeded in producing long, nearly continuous vortex pins along the c-axis in YBa2Cu3O7−δ (YBCO), in the form of self-assembled stacks of BaZrO3 (BZO) nanodots and nanorods. The nanodots and nanorods have a diameter of ∼2–3 nm and an areal density (‘matching field’) of 8–10 T for 2 vol.% incorporation of BaZrO3. In addition, four misfit dislocations around each nanodot or nanorod are aligned and act as extended columnar defects. YBCO films with such defects exhibit significantly enhanced pinning with less sensitivity to magnetic fields H. In particular, at intermediate field values, the current density, Jc, varies as Jc∼H−α, with α∼0.3 rather than the usual values 0.5–0.65. Similar results were also obtained for CaZrO3 (CZO) and YSZ incorporation in the form of nanodots and nanorods within YBCO, indicating the broad applicability of the developed process. The process could also be used to incorporate self-assembled nanodots and nanorods within matrices of other materials for different applications, such as magnetic materials.
The motion of large bubbles in horizontal channels

An experimental investigation of a large long air bubble moving into stationary water in a horizontal channel of rectangular cross-section is presented and three well-defined flow régimes for the water discharged beneath the bubble are described. The influence of surface tension on the bubble velocity is explained using the hypothesis that the radius of curvature of the two-phase interface close to the upper wall does not vary greatly with channel depth and is close to the theoretical value for a channel of such depth that the bubble is just motionless.
Imaging Simulations of Large‐Scale Flux Recovery at Millimeter Wavelengths

We present multiple‐field imaging simulations that explore the issue of large‐scale flux recovery using five current and future millimeter‐wavelength interferometers. The simulations show that nonlinear deconvolutions routinely applied to interferometric maps interpolate and extrapolate to unsampled spatial frequencies and thereby reconstruct much larger scale structures than an analytical treatment of the flux recovery issue would suggest. We show that the fraction of flux recovered for a given observation is a function of the signal‐to‐noise ratio (S/N) of the map; however, even for S/Ns as low as 3, a deconvolved map reconstructs more flux than an un‐deconvolved map. Both the noise‐free and the noise‐added simulations demonstrate that in order to make accurate maps of even moderately large (≳20″) sources at millimeter wavelengths, it is generally necessary to include single‐dish (“total‐power”) or very short spacing data. We demonstrate that for high‐S/N data, how well an individual telescope recovers large‐scale structure for a mosaiced observation is more closely related to the minimum distance between its dishes, Smin - D, than to the minimum center‐to‐center distance, Smin. For a source that is large in one dimension but small in another (e.g., an elliptical Gaussian), the simulations show that the flux recovery is more closely determined by the small dimension than by the long dimension. This may help with the real imaging of spiral galaxies, where the rotation tends to confine the emission in any given channel map to a relatively small region in one dimension. These simulations were motivated by our work with mosaics from the Berkeley‐Illinois‐Maryland Association Survey of Nearby Galaxies (BIMA SONG), but the results apply generally to millimeter‐wavelength interferometric images.
of N-gram

The present study investigates the processing and production of four-word sequences such as I don’t really know , at the age of , and I think it’s the . Specifically, we investigate the influence of families of probabilistic measures such as unigram, bigram, trigram, and quadgram frequency of occurrence, logarithmic (log) probability of occurrence, and mutual information. Log probability of occurrence emerged as the predominant predictor family in the onset latency analysis, suggesting that recognition is mainly underpinned by competition between a target N-gram and its family members. In contrast, the amount of experience one has with an N-gram (frequency of occurrence) surfaced as the most prominent predictor in production. Further, probabilistic measures tied to trigrams surfaced as the best predictors in the onset latency analysis, while the measures tied to unigrams were most predictive of production durations. finally, the interactions between probabilistic measures tied to unigrams, bigrams, trigrams, and quadgrams suggest that N-grams of different lengths are processed in parallel in both recognition and production.
Lanczos algorithms for large symmetric eigenvalue computations

0 Preliminaries: Notation and Definitions. - 0.1 Notation. - 0.2 Special Types of Matrices. - 0.3 Spectral Quantities. - 0.4 Types of Matrix Transformations. - 0.5 Subspaces, Projections, and Ritz Vectors. - 0.6 Miscellaneous Definitions. - 1 Real' symmetric' Problems. - 1.1 Real Symmetric Matrices. - 1.2 Perturbation Theory. - 1.3 Residual Estimates of Errors. - 1.4 Eigenvalue Interlacing and Sturm Sequencing. - 1.5 Hermitian Matrices. - 1.6 Real Symmetric Generalized Eigenvalue Problems. - 1.7 Singular Value Problems. - 1.8 Sparse Matrices. - 1.9 Reorderings and Factorization of Matrices. - 2 Lanczos Procedures, Real Symmetric Problems. - 2.1 Definition, Basic Lanczos Procedure. - 2.2 Basic Lanczos Recursion, Exact Arithmetic. - 2.3 Basic Lanczos Recursion, Finite Precision Arithmetic. - 2.4 Types of Practical Lanczos Procedures. - 2.5 Recent Research on Lanczos Procedures. - 3 Tridiagonal Matrices. - 3.1 Introduction. - 3.2 Adjoint and Eigenvector Formulas. - 3.3 Complex Symmetric or Hermitian Tridiagonal. - 3.4 Eigenvectors, Using Inverse Iteration. - 3.5 Eigenvalues, Using Sturm Sequencing. - 4 Lanczos Procedures with no Reorthogonalization for Real Symmetric Problems. - 4.1 Introduction. - 4.2 An Equivalence, Exact Arithmetic. - 4.3 An Equivalence, Finite Precision Arithmetic. - 4.4 The Lanczos Phenomenon. - 4.5 An Identification Test, 'Good' versus' spurious' Eigenvalues. - 4.6. Example, Tracking Spurious Eigenvalues. - 4.7 Lanczos Procedures, Eigenvalues. - 4.8 Lanczos Procedures, Eigenvectors. - 4.9 Lanczos Procedure, Hermitian, Generalized Symmetric. - 5 Real Rectangular Matrices. - 5.1 Introduction. - 5.2 Relationships With Eigenvalues. - 5.3 Applications. - 5.4 Lanczos Procedure, Singular Values and Vectors. - 6 Nondefective Complex Symmetric Matrices. - 6.1 Introduction. - 6.2 Properties of Complex Symmetric Matrices. - 6.3 Lanczos Procedure, Nondefective Matrices. - 6.4 QL Algorithm, Complex Symmetric Tridiagonal Matrices. - 7 Block Lanczos Procedures, Real Symmetric Matrices. - 7.1 Introduction. - 7.2 Iterative Single-vector, Optimization Interpretation. - 7.3 Iterative Block, Optimization Interpretation. - 7.4 Iterative Block, A Practical Implementation. - 7.5 A Hybrid Lanczos Procedure. - References. - Author and Subject Indices.
Pick's theorem

Some years ago, the Northwest Mathematics Conference was held in Eugene, Oregon. To add a bit of local flavor, a forester was included on the program, and those who attended his session were introduced to a variety of nice examples which illustrated the important role that mathematics plays in the forest industry. One of his problems was concerned with the calculation of the area inside a polygonal region drawn to scale from field data obtained for a stand of timber by a timber cruiser. The standard method is to overlay a scale drawing with a transparency on which a square dot pattern is printed. Except for a factor dependent on the relative sizes of the drawing and the square grid, the area inside the polygon is computed by counting all of the dots fully inside the polygon, and then adding half of the number of dots which fall on the bounding edges of the polygon. Although the speaker was not aware that he was essentially using Pick's formula, I was delighted to see that one of my favorite mathematical results was not only beautiful, but even useful. (From DeTemple [1989].)
Impact of interface controlling layer of Al2O3 for improving the retention behaviors of In-Ga-Zn oxide-based ferroelectric memory transistor

We characterized the nonvolatile memory thin-film transistors, which was composed of an amorphous indium-gallium-zinc oxide (α-IGZO) active channel and a ferroelectric poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] gate insulator, and investigated the impact of an interface controlling layer. Excellent device performances, such as the field-effect mobility of 60.9 cm2 V−1 s−1, the subthreshold swing of 120 mV/dec, and the memory window of 6.4 V at ±12 V programming, were confirmed for the device without any interface layer. However, the memory retention time was very short. The retention behaviors could be dramatically improved when 4 nm thick Al2O3 layer was introduced between the P(VDF-TrFE) and α-IGZO.
USE OF RECIPROCITY THEOREM FOR COMPUTATION OF LOW-FREQUENCY RADIATION PATTERNS

Starting with a simple word statement of the reciprocity which exists between forces and displacements in a general elastic solid, it is shown that low‐frequency radiation of shear and compressional waves from relatively complex sources can be obtained by solving relatively simple problems in static elasticity. Illustrative examples include radiation from radial and tangential pairs of forces acting on the wall of a cylinder, pressure in a finite cylinder, and a pair of radial forces in a hole in a plate. For the last case, measurements in a plexiglas plate compare favorably with computations.
Thunderstorm-Generated Gravity Waves

Abstract Internal gravity waves have been recorded at London, Ontario, using a network of three microbarographs. It has been shown from experimental observations that internal gravity waves are generated by thunderstorms. The spectral behavior of these waves has been found to be essentially monochromatic. A simple model for the generation of these waves is presented and it is shown that the observed properties of the waves are in good agreement with the features of the suggested model.
Periodic Solutions for Non-linear Equations of Structured Populations

We show the existence of non-trivial periodic solutions for a class of non-linear equations, model of age-structured populations. To this aim we use the theory of Centre Manifold for a class of abstract differential equations introduced by Desch and Schappacher, and show that a Hopf Bifurcation Theorem can be proved for this class of equations. Finally, we consider some special cases, and present an algorithm for the determination of the type of bifurcation, and show that in the considered cases the bifurcation is always supercritical.
A Large H I Shell surrounding the Wolf-Rayet Star HD 191765

Our H I maps reveal the existence of a nearly complete shell at a velocity of vsys = -11.44 km s-1 (Rs ≈ 20.9 pc, vexp ≈ 9.9 km s-1, MH I ≈ 1830 M⊙), which, mainly for morphological reasons, we associate with HD 191765 (although a contribution from the nearby W-R star HD 192103 cannot be totally excluded). The dynamical age of this bubble (∼1.3 × 106 yr) suggests that it was mainly blown during the main-sequence progenitor O-star phase. The kinematic distance corresponding to a local standard of rest velocity of -11 km s-1 is approximately 5 kpc, which is incompatible with the association distance of HD 191765 of 2.1 kpc. Therefore, we conclude that the H I bubble we have detected was blown in gas already in movement with respect to normal Galactic rotation for this region. There is independent evidence that gas at this velocity is present in this line of sight. Recent Hipparcos data analyzed by Moffat et al. give a supersonic proper motion for HD 191765 (projected velocity ∼52 km s-1 at a position angle on the sky of P.A. = -38°). This velocity vector points away from a position very close to the center of the H I bubble, which strengthens the hypothesis of a physical link with the W-R star. The supersonic velocity of the star with respect to the interstellar medium might have generated some compression of the interstellar medium in the southwest region, rendering the Hα gas brighter in that direction with respect to the surroundings.
Combined Dynamics of Boundary and Interior Perturbations in the Eady Setting

Abstract A theoretical study is undertaken of the relative influence of intermediate-level, near-surface, and tropopause-level perturbations upon flow development and cyclogenesis. The study is based upon two complementary quasigeostrophic models with consideration given to different types of perturbations of Eady-like basic states. First, the standard linear Eady model is refined to include an interior, vertically localized potential vorticity (PV) wave perturbation, and the wave's influence upon the growth of the boundary waves is examined as a function of its vertical location and its initial phase and amplitude. It is shown that the pseudoresonance arising from the interaction of the interior PV wave with a surface-confined wave is highly transient and comparatively weak. In contrast, a PV wave located at midlevel can have supraexponential sustained impact upon the perturbation growth that results from a combination of its direct forcing effect and its ability to maintain the two Eady edge waves near .
Properties of Jupiter's magnetospheric turbulence observed by the Galileo spacecraft

In collisionless plasmas, turbulence is thought to play an important role in mass transport and energy dissipation. Magnetic fluctuations in the Jovian magnetosphere are essential in a turbulent state. Previous studies of that turbulence have focused on the large scales using low time resolution of magnetic field data. Here we extend those studies to cover a wider range of scales by combining both low and high‐time‐resolution data of Galileo magnetometer. We use particle data from the plasma instrument and include energetic particle contributions to estimate the local plasma parameters. We obtain 11 power spectra of magnetic field in the frequency range of 10−4–1 Hz, which covers both magnetohydrodynamics and ion kinetic scales. The frequencies of the evidenced spectral breaks are found to be relatively well correlated with the characteristic scales of heavy ion. The spectral indices below and above the spectral breaks are found to be broad and cover the ranges of 0.6–1.9 and 1.7–2.5, respectively. An analysis of higher‐order statistics shows an intermittent feature of the turbulence, found to be more prominent in the plasma sheet than in the lobe. Furthermore, a statistical survey of the power of the fluctuations using low‐time‐resolution data suggests a radially varying dawn‐dusk asymmetry: the total power is larger in the duskside (dawnside) at <50 RJ (>80 RJ), which would reflect flow shear and global magnetospheric activity.
Regional Characteristics of Scale-based Precipitation Systems from Ten Years of TRMM PR Data

The regional characteristics of scale-based precipitation systems on the basis of the size of the systems were investigated using a 10-year dataset from the Precipitation Radar aboard the Tropical Rainfall Measuring Mission satellite. The size of a precipitation system is defined as the number of contiguous rain pixels. The first result is on the diurnal features of precipitation systems stratified by size as small ( 104 km2) rain area and stratiform/convective types, respectively. It was found that large overland precipitation systems developed mostly in the evening, following the early-afternoon rainfall maxima of small systems. While large systems showed clear migration properties, small systems had rain peaks at nearly the same local time, that is, without propagation. The diurnal features of small systems were almost uniform over the land or oceans. However, the vertical profiles of rainfall rates obtained for small systems exhibited regional variations. The second result is on the spatial and interannual variations in extreme events. The extreme events are defined as 1000 systems with the highest volumetric rainfall. These events were unevenly distributed and appeared particularly around the mouth of the La Plata basin and the northwestern and western Pacific. The year-to-year variations in these extreme events over the global tropics were consistent with the occurrence of tropical cyclones over the western Pacific.
Mass Flow Rate Control in a Cylindrical Capillary by an AC Electric Field at High Zeta Potential

In the present study we obtain the mass flow rate characteristics in a cylindrical capillary due to a time-periodic electric field at high zeta potential, extending the conventional thin electrical double layer limit. The capillary cross section is divided into two regimes, the high potential regime (near surface region), and the low potential regime (capillary central line region). To obtain the potential distribution inside the capillary, the nonlinear part of the Poisson-Boltzmann equation is approximated by a linear function for the low potential regime and by an exponential function for high potential regime. Using the approximated potential distributions, the governing electro-hydrodynamic equation is then solved semi-analytically, where the imposed electric field and the velocity field is assumed to have the form which consist of a steady state term and a time-periodic term. A theoretical investigation on the mass flow rate, the phase difference is carried out on the basis of pulsation frequency, e.