Miracle-dz/UniFAR-FTUs huggingface dataset:
Molecular gas in the type 1 Seyfert galaxy NGC 7469: implications for nuclear activity

The results of a search for 2.12-micron H2 1-0 S(1) line emission from the nuclear (not greater than 1 kpc) region in 11 active galaxies are reported. The galaxies observed included type 1 and type 2 Seyferts, LINERs, and starburst nucleus galaxies. H2 emission was detected in one galaxy, the classical type 1 Seyfert NGC 7469. Also reported is the detection of very luminous C-12O 2.6-mm emission from NGC 7469, and optical narrow-band images and long-slit spectroscopy data concerning the ionized gas in this galaxy are presented. These data imply that NGC 7469 not only contains a highly active compact nucleus but also is undergoing a luminous circumnuclear (few-kpc scale) starburst. Most of the other galaxies with known H2 emission also seem to be composite monster/starburst systems and/or interacting galaxies. This result may arise because the molecular gas is associated with the starburst, while the primary form of the mechanical energy necessary to shock-excite the H2 is either outflow (possibly a wind) driven by the compact active nucleus or noncircular motions of gravitational origin. In either case, high-velocity (greater than 300 km/s) collisions between dense molecular clouds and a more ubiquitous, less dense gas phase can drive slow (10-30 km/s)more » shocks into the molecular clouds, exciting the observed H2 emission. 68 references. « less
Toward a taxonomy of coherence relations

Understanding a discourse means constructing a coherent representation of that discourse. Inferring coherence relations, such as cause‐consequence and claim‐argument, is a necessary condition for a discourse representation to be coherent. Despite some descriptively fairly adequate proposals in the literature, there is still no theoretically satisfying account of the links that make a discourse coherent. An adequate account of the relations establishing coherence has to be psychologically plausible, because coherence relations are ultimately cognitive relations. We are proposing a taxonomy that classifies coherence relations in terms of four cognitively salient primitives, such as the polarity of the relation and the pragmatic or semantic character of the link between the units. A classification experiment using fragments of written discourse showed that the 12 classes of coherence relations distinguished in the taxonomy appear to be intuitively plausible and applicable. A second experiment investigating t.
Robust modeling using the generalized epsilon-skew-t distribution

In this paper, an alternative skew Student-t family of distributions is studied. It is obtained as an extension of the generalized Student-t (GS-t) family introduced by McDonald and Newey [10]. The extension that is obtained can be seen as a reparametrization of the skewed GS-t distribution considered by Theodossiou [14]. A key element in the construction of such an extension is that it can be stochastically represented as a mixture of an epsilon-skew-power-exponential distribution [1] and a generalized-gamma distribution. From this representation, we can readily derive theoretical properties and easy-to-implement simulation schemes. Furthermore, we study some of its main properties including stochastic representation, moments and asymmetry and kurtosis coefficients. We also derive the Fisher information matrix, which is shown to be nonsingular for some special cases such as when the asymmetry parameter is null, that is, at the vicinity of symmetry, and discuss maximum-likelihood estimation. Simulation studies for some particular cases and real data analysis are also reported, illustrating the usefulness of the extension considered.
Radio Emission by Plasma Oscillations in Nonuniform Plasmas

Equations of motion for small-amplitude plasma oscillations interacting with the electromagnetic field in slowly varying density or temperature gradients are set up. The radio noise excited by a wave packet of plasma oscillations traversing such gradients using the WKB approximation is then calculated. A similar calculation is made for a density discontinuity. (auth)
Gaussian copula under multiscale volatility

A copula is a multidimensional joint distribution function on random variables with uniform distribution. Gaussian copula is a special kind of copula that is widely applied in the study of financial markets. Although it is a very popular tool, Gaussian copula has an obvious shortcoming—it cannot show the tail dependence, which is an important property of the copula. The essence of tail dependence is the interdependence when the extreme events occur. Fouque and Zhou (Perturbed Gaussian copula. 2006; submitted) have discussed perturbed Gaussian copula under one stochastic volatility factor with a fast scale, and they used singular perturbation techniques to derive an approximate copula. Our work can be treated as the generalization and extension of the work of Fouque and Zhou (Perturbed Gaussian copula. 2006; submitted). In our paper, we will investigate the problem where the volatilities of goal variables are driven by two random variables, namely, it is a multiscale volatility model. In the model, we use a fast mean reverting Ornstein–Uhlenbeck process to depict the first scale, and a slow varying diffusion process to depict the second scale. We also use the regular and singular perturbation methods developed in the work of Fouque et al. (Multiscale Model. Simul. 2003; 2(1):22–42) to derive the approximate copula. We show that some tail dependence can be restored by Gaussian copula under multiscale stochastic volatility. Copyright © 2008 John Wiley & Sons, Ltd.
Fault Classification using Pseudomodal Energies and Probabilistic Neural Networks

This paper introduces a new fault identification method that uses pseudomodal energies to train probabilistic neural networks (PNNs). The proposed procedure is tested on a population of 20 cylindrical shells and its performance is compared to the procedure which uses modal properties to train probabilistic neural networks. The PNNs trained using pseudomodal energies provide better classification of faults than the PNNs trained using the conventional modal properties.
Local isotropy and anisotropy in a high-Reynolds-number turbulent boundary layer

High-frequency fluctuations of temperature and of longitudinal and vertical velocity components have been measured with high-resolution probes in order to test the local-isotropy assumption. The simultaneous measurements of u’, w’, θ’ and the measurements in two space points with various separations in either the longitudinal or transverse directions were made in the large boundary layer (Rλ = 616) of the I.M.S.T. Air-Sea Interaction Simulation Tunnel. There is consistent evidence that the local-isotropy assumption is satisfied by the velocity field at all scales smaller than twenty times the Kolmogorov microscale (η ≈ 0.27 × 10−3 m), i.e. in the dissipative range of scales but not in the expected inertial subrange. The direct comparisons of the lateral and longitudinal temperature autocorrelation and structure functions show that the temperature field does not verify the isotropy assumption at all scales greater thanor equal to 37 and presumably at even smaller scales. This is confirmed by the study of the temperature-increment skewness and flatness factors. The spectral distribution -of the non-zero derivative skewness (S(θ) = +0.9) shows that it is essentially contributed by those scales for which the dynamic field satisfies isotropy.
MOTIVATION AND CAPACITY IN CHILDREN'S CREATIVITY1

An attempt was made to distinguish between capacity and motivational interpretations of individual differences in children's creativity. Creativity tasks required the child to name as many ideas as he could that met a simple problem requirement. Tasks were given under “base line” conditions and with a reward of one cent for each idea given. If task motivation is the critical determinant of performance, reward should decrease the differences between high and low scorers by decreasing the range of motivation with which the task is approached. However, if these individual differences reflect capacity, reward should increase or leave unchanged the difference in number of ideas given by more and less fluent children. Reward led to an increase in mean number of ideas which was consistent across levels of creativity. Thus, while motivating conditions may alter the level at which the group performs, the data suggest that individual differences in performance derive from differences in capacity rather than motivation for divergent ideational production.
Hot electron diagnostic in a solid laser target by K-shell lines measurement from ultraintense laser–plasma interactions (3×1020 W/cm2,⩽400 J)

Characterization of hot electron production from an ultraintense laser–solid target plasma interaction by using a buried molybdenum K-shell fluor layer technique has been reported. Laser energy was typically 400 J and its intensity was from 2×1018 up to 3×1020 W cm−2 at 20 TW to 1 PW laser power by changing pulse duration from 20 ps down to 0.5 ps. X-ray background noise level was significantly greater, i.e., gamma flash, in the shorter pulse experiments. Data analysis procedures for the experiments were developed. The conversion efficiency from the laser energy into the energy, carried by hot electrons, has been estimated to be ∼50% at 3×1020 W cm−2 laser intensity, higher than ∼18% at 1019 W cm−2 and ∼12% at 2×1018 W cm−2 intensity.
Compact Wideband Bandpass Filter Using Hybrid Hairpin and Half Wave Parallel Coupled Resonator in Multilayer Microstrip Configuration for X-band Application

This paper presents a new design of wideband filter for X-band application using hybrid hairpin resonator and half wave coupled line resonator in multilayer microstrip configuration. Different resonator shapes were put on two substrates with different dielectric constants. In this work R/T Duroid 6010 and R/T Duroid 5880 with dielectric constant 10.2 and 2.2 respectively were used as the substrates, producing a very small filter size, only at 10 × 10 cm2. This configuration is not only producing compact size filter, but also high bandwidth since the overlapping gap between two resonators produces a tight coupling which is needed for wideband filter. The filter can cover whole X-band frequencies by producing 44% bandwidth at 10.2 GHz center frequency with excellent responses, where the measured passband return loss for this filter is better than –12.5 dB and the insertion loss is better than 2.3 dB.
The Maintenance of Low-Frequency Atmospheric Anomalies

Abstract A linear budget is used to ascertain which of several proposed processes are most important in maintaining four prominent low-frequency perturbation patterns in a perpetual January general circulation model simulation with fixed ocean temperatures. In the budget technique the time-average model equations are separated into those terms that are in common with the steady, adiabatic linearized form of the model equations and the remaining terms, which are treated as forcing terms. By examining the linear response to each of these forcing terms for prominent episodes of the low-frequency patterns, the terms that are most important in maintaining the low-frequency patterns can be determined.The results indicate that interactions between the low-frequency patterns and the time-mean zonal asymmetries of the model climate are crucial to the maintenance of the patterns. Of equal importance are anomalous fluxes from transients, without which the low-frequency anomalies would not be maintained. Vorticity fl.
A new spectroscopic technique for imaging the spatial distribution of nonradiative defects in a scanning transmission electron microscope

A new spectroscopic technique for imaging the spatial distribution of nonradiative defects in semiconductor materials is presented. The technique combines the versatility and sensitivity of deep‐level transient spectroscopy (DLTS) with the capability for defect analysis at high resolution of the scanning transmission electron microscope. This scanning DLTS method (SDLTS) is illustrated by observing Cu‐related defect centers in Ga1−xAlxAs epitaxial layers. A high sensitivity (3×1015 Cu defects cm−3 have been detected) and a spatial resolution of 2 μ or better illustrate the potential of the technique for the study of the electrical behavior of defects in semiconductor devices.
Rapid Changes of Photospheric Magnetic Fields around Flaring Magnetic Neutral Lines

In this paper we study the short-term evolution of magnetic fields associated with five flares in δ-sunspots. We concentrate on the analysis of the magnetic gradient along the flaring neutral lines (NLs). Obvious changes of the magnetic gradient occurred immediately and rapidly following the onset of each flare. A rapid gradient increase was found to be associated with three events, while a decrease was associated with the other two. The changes were permanent, and therefore not likely due to the flare emissions. In addition, we evaluated the mean relative motions between the two magnetic polarities in these δ-regions, in the directions parallel and perpendicular to the flaring NLs. We derived the mean positions of the two magnetic polarities using a center-of-mass (CoM) calculation and found that (1) converging motions correspond to a gradient increase and diverging motions, to a decrease; (2) for all the events, there appeared a sudden release of magnetic shear associated with each flare, signified by a decrease of CoM separation between 500 and 1200 km in the direction parallel to the NLs. Combining the findings presented here with those in previous papers, we propose that these results are evidence of magnetic reconnection at or close to the photosphere. When an active region is away from the solar disk center, the reconnected transverse fields cause an apparent increase of the flux in the polarity toward the limb and a decrease for the polarity closer to the disk center. This observational pattern was indeed found for all 10 available events that have been studied in the literature and in this paper. Finally, we offer some predictions for future observations when high-quality vector magnetogram sequences become available.
Does the Baryon Fraction in Clusters Imply an Open Universe

Clusters are the largest objects in the universe where one can measure both the total baryonic mass and the total mass. Under the assumption that the baryonic mass fraction of clusters should be equal to the universal value, it has been argued that comparing the baryonic mass fraction of clusters to the value derived by nucleosynthesis constraints requires an open universe. We test these arguments using numerical simulations. We find that the cluster total masses are underestimated and that the baryons are more concentrated in clusters. These two effects together reconcile the observed cluster baryonic mass fraction with a flat universe
Distribution of radial energy deposition around the track of energetic charged particles in silicon

The distribution of radial energy deposition around the track of carbon, aluminum, and iron ions with energy range from 10 MeV to 10 GeV inside silicon was calculated. A simple and direct approach was developed utilizing a corrected semianalytical model. The results of the present work agree very well with Monte Carlo calculations as well as stopping power tables.
On the statistical distribution of the widths and spacings of nuclear resonance levels

Abstract If the average spacing of the resonance levels is very small as compared with the range of energy in which the spacing or width of the levels changes appreciably on the average, one can speak of a statistical distribution of the level spacings and widths. The question then comes up naturally, whether the ‘distribution law’ for width and spacing is different for protons, neutrons, etc., i.e. whether it depends on the long-range interaction of the scattered particle. It is pointed out that while the average width must depend on the long-range interaction (on account of the penetration factor) the distribution of the widths, if these are measured in terms of their average, can be expected to be independent therefrom. In the case of the level spacings, not only the distribution about the average, but the average itself is also independent of the long-range interaction. It is pointed out, incidentally, that the logarithmic derivative of the wave function at the surface of the nucleus will have, on the whole, a positive value between resonances because of the greater effect of the high-energy resonances than that of the bound states.
Three-Dimensional Object Reconstruction and Recognition Using Computational Integral Imaging and Statistical Pattern Analysis

In this paper, we discuss computational reconstruction and statistical pattern classification using integral imaging. Three-dimensional object information is numerically reconstructed at arbitrary depth-levels by averaging the corresponding pixels. The longitudinal distance and object boundary are estimated where the standard deviation of the intensity is minimized. Fisher linear discriminant analysis combined with principal component analysis is adopted for the classification of out-of-plane rotated objects. The Fisher linear discriminant analysis maximizes the class-discrimination while the principal component analysis minimizes the error between the original and the restored images. The presented method provides promising results for the distortion-tolerant pattern classification.
A family of Hurwitz groups with non-trivial centres

In this paper a new family of quotients of the triangle group < x, y, z | x2 = y3 = z7 = xyz = 1 > is obtained. It is shown that for every positive integer m divisible by 3 there is a Hurwitz group of order 504m6 having a centre of size 3, and as a consequence there is a Riemann surface of genus 6m6 + 1 with the maximum possible number of automorphisms.
Transient growth of droplet instabilities in a stream

Droplet deformation is the first stage of all aerodynamically induced-breakups, considerably affecting the characteristics of the atomization. In the present study, using an adaptive volume of fluid method, two and three-dimensional direct numerical simulations have been performed to understand droplet deformation. A high Reynolds number and a range of relatively high Weber numbers are chosen, addressing the shear breakup of droplets in a stream. The study is focused on the initiation and growth of instabilities over the droplet. The role of Kelvin-Helmholtz and Rayleigh-Taylor instabilities in wave formation and azimuthal transverse modulation are shown and the obtained results for the most amplified wave-numbers are compared with instability theories for zero and non-zero vorticity layers. The present results for the most amplified wave-numbers and deformation topologies are in good agreement with the previous experimental results.
Preliminary Investigation on Lithium Hydride as Fuel for Solid-Fueled Scramjet Engines

The aim of this work is to study the combustion of a LiH grain in a supersonic airstream, as a preliminary to investigate its potential as fuel in a solid-fueled scramjet. This hydride is interesting because it reacts exothermically with many substances and contains hydrogen, suggesting its use when a much higher density (compared with that of LH 2 ) would be beneficial. In fact, LiH releases H 2 and Li by thermal decomposition; at the same time, the Li produced behaves as a highly energetic fuel in the presence of a high-temperature airstream. Because of the scarce data present in literature, the thermochemical properties of LiH and its decomposition were calculated, estimated, or modeled, and issues associated with its combustion in a hot supersonic stream were investigated; a simplified physical model describing its vaporization and combustion was built that was successively simulated by means of a computational fluid dynamics code. Results show that LiH is an ideal candidate for solid-fueled-scramjet applications, behaving not only as a high-energy-density bifuel system, but also as a safe and compact hydrogen carrier. An intense flame zone is predicted to be present over the decomposing surface and downstream of the grain; the flame is stable and high temperatures (on the order of 2900 K) are obtainable. Moreover, specific impulse and thrust density predicted at a flight Mach = 7 are also interesting, being 10,000 and 200―300 m/s, respectively.
Some remarks on bonus systems in automobile insurance

Abstract Extract For a long time premiums in automobile insurance in Sweden have been regulated by bonus systems (for a definition see 1.1.1). Several such systems have been used and still more suggested. This paper deals with the basic principles underlying the idea of a bonus system: how does it work under various conditions and what should be the purpose of it. Although these questions have been discussed a good deal internally among actuaries, they have not got the attention they deserve in the actuarial journals. This may be due at least partly to the difficulty of formulating the problem in a matematical form and in a realistic way.
Dynamics of relativistic magnetized blast waves

The dynamics of a relativistic blast wave propagating through a magnetized medium is considered, taking into account possible inhomogeneities of density and magnetic field and additional energy supply. Under the simplifying assumption of a spherically symmetric explosion in a medium with toroidal magnetic field self-similar solutions for the internal dynamics of the flow are derived. In the weakly magnetized case, when the bulk of the flow may be described by the unmagnetized solutions, there is a strongly magnetized sheath near the contact discontinuity (when it exists). Self-similar solutions inside the sheath are investigated. In the opposite limit of strongly magnetized upstream plasma new analytical self-similar solutions are found. Possible application to the physics of gamma-ray bursts is discussed.
Optical back-action in silicon nanowire resonators: bolometric versus radiation pressure effects

We study optical back-action effects associated with confined electromagnetic modes in silicon nanowire resonators interacting with a laser beam used for interferometric read-out of the nanowire vibrations. Our analysis describes the resonance frequency shift produced in the nanowires by two different mechanisms: the temperature dependence of the nanowire's Young's modulus and the effect of radiation pressure. We find different regimes in which each effect dominates depending on the nanowire morphology and dimensions, resulting in either positive or negative frequency shifts. Our results also show that in some cases bolometric and radiation pressure effects can have opposite contributions so that their overall effect is greatly reduced. We conclude that Si nanowire resonators can be engineered for harnessing back-action effects for either optimizing frequency stability or exploiting dynamic phenomena such as parametric amplification.
Epitaxial strain-induced changes in the cation distribution and resistivity of Fe-doped CoFe2O4

The distribution of cations in Fe-doped cobalt ferrite (Co1−xFe2+xO4) is investigated as a function of epitaxial strain through x-ray absorption measurements of samples grown on SrTiO3, MgO, and CoCr2O4-buffered MgAl2O4 (001). In agreement with recent theoretical calculations, compressive (tensile) strain results in the films having a larger (smaller) degree of cation inversion for iron doping levels up to x = 0.62. Measurements of the resistivity further conclude that the degree of cation inversion has a direct effect on the size of the bandgap for stoichiometric CoFe2O4, an effect that is reduced as the iron doping level is increased.