Miracle-dz/UniFAR-FTUs huggingface dataset:
Asymptotic Theory for Regressions with Smoothly Changing Parameters

Abstract: We derive asymptotic properties of the quasi-maximum likelihood estimator of smooth transition regressions when time is the transition variable. The consistency of the estimator and its asymptotic distribution are examined. It is shown that the estimator converges at the usual -rate and has an asymptotically normal distribution. Finite sample properties of the estimator are explored in simulations. We illustrate with an application to US inflation and output data.
Surface BR Photometry of Newly Discovered Dwarf Elliptical Galaxies in the Nearby Sculptor and Centaurus A Groups

Prompted by the recent finding of a large number of gas-rich dwarf irregular galaxies in the nearby southern galaxy groups Sculptor (Scl) and Centaurus A (Cen A) we carried out a complementary survey to search for members of the gas-poor dwarf elliptical (dE) galaxy family. In total 18 dE candidates were identified on SRC Sky Survey films covering the group regions. For five dE's in the Scl group and five in the Cen A group, membership information is available from surface brightness fluctuations distance measurements; two dEs in each group also have independent redshift measurements. The remaining eight galaxies have been associated to the groups based on their morphology. We acquired deep B- and R-band CCD images for all galaxies and determined their photometric and structural parameters. According to the magnitude range covered, -14 < MB < -9 (not counting the bright dS0 NGC 59), these objects are local dwarf spheroidal (dSph) analogues. The surface brightness profiles of most dwarfs are strongly nonexponential but are perfectly explained by the three-parametric Sérsic law. The best-fitting Sérsic parameters are compared with corresponding data for Virgo dE's and dSph's. The present dEs follow the relations between the Sérsic parameters and absolute B-band magnitude for Virgo dE's and local dwarfs, thus confirming the membership in the Scl and Cen A groups, respectively. Most of our dwarfs exhibit color gradients in (B-R)0, in the sense of a reddening outward. We also show and discuss the sky distributions and B-band luminosity functions of the Scl and Cen A groups. The completeness magnitude for both populations (from the present survey) is estimated to be M ≈ -13. We find that the composite luminosity function of four nearby galaxy groups is well fitted by a Schechter function down to M = -14 with a faint end slope α = -1.29(±0.10). In the appendices we present best-fitting Sérsic profile parameters for the dSph members of the Local Group and introduce two new dwarf irregulars found in the Cen A group.
Pore Pressure Diffusion and Onset of Induced Seismicity

The Raton Basin of Southern Colorado and Northern New Mexico experienced a significant increase in seismicity over the last several decades, including two M5+ earthquakes. The increase in seismicity started soon after an increase in wastewater disposal associated with coal‐bed methane production. Twenty‐nine wastewater injection wells have operated in the Basin, with several high‐rate injectors located within a kilometer of the most seismically active regions. We developed a pore pressure model to investigate the relationship between pore pressure diffusion and onset of induced seismicity, with an emphasis on the Trinidad fault zones. Our model indicates that sufficient pore pressure increase had accumulated on the northern extent of the Trinidad fault zone to induce seismicity at the time of early‐stage seismic activity. The hydrogeologic architecture of the Basin played a key role in controlling pore pressure perturbation. The basal sedimentary interval with moderately low diffusivity restricted vertical pore pressure diffusion, creating a substantial lag time between wells becoming active and the expression of perturbation in the fault zones. The spatiotemporal relationship between early‐stage seismicity and wastewater injection in conjunction with modeled pore pressures suggests that the early‐stage seismicity in the Raton Basin was likely triggered by pore pressure diffusion.
Observations of Brown Dwarfs

▪ Abstract The brown dwarfs occupy the gap between the least massive star and the most massive planet. They begin as dimly stellar in appearance and experience fusion (of at least deuterium) in their interiors. But they are never able to stabilize their luminosity or temperature and grow ever fainter and cooler with time. For that reason, they can be viewed as a constituent of baryonic “dark matter. ” Indeed, we currently have a hard time directly seeing an old brown dwarf beyond 100 pc. After 20 years of searching and false starts, the first confirmed brown dwarfs were announced in 1995. This was due to a combination of increased sensitivity, better search strategies, and new means of distinguishing substellar from stellar objects. Since then, a great deal of progress has been made on the observational front. We are now in a position to say a substantial amount about actual brown dwarfs. We have a rough idea of how many of them occur as solitary objects and how many are found in binary systems. We have ob.
Common Slope Tests for Bivariate Errors‐in‐Variables Models

Summary Likelihood ratio tests are derived for bivariate normal structural relationships in the presence of group structure. These tests may also be applied to less restrictive models where only errors are assumed to be normally distributed. Tests for a common slope amongst those from several datasets are derived for three different cases – when the assumed ratio of error variances is the same across datasets and either known or unknown,and when the standardised major axis model is used. Estimation of the slope in the case where the ratio of error variances is unknown could be considered as a maximum likelihood grouping method. The derivations are accompanied by some small sample simulations,and the tests are applied to data arising from work on seed allometry.
Patterns at primary Hopf bifurcations at a plexus of identical oscillators

Mathematically, an oscillator is a system of ordinary differential equations with a periodic limit cycle, usually arising from a Hopf bifurcation for a stationary solution. A plexus is a collection of such oscillators, coupled to each other via one-way or two-way communication channels. Plexuses model a wide number of phenomena in the mathematically oriented sciences. The primary Hopf bifurcation theory of such a plexus is developed. There are features of the bifurcating solutions which depend only on the combinatorics of the plexus and not on the details of the individual oscillators. Such features are called the pattern of the bifurcation. The relation of patterns to the modes of small oscillations of mechanical systems is discussed. More detailed information is developed for weak coupling. The theory is used to analyze two particular types of plexuses; viz, rings and lines of oscillators. It is then shown that the structure of a plexus permits numerical bifurcation computations to be made more efficien.
Effect of virtual mass force on prediction of pressure changes in condensing tubes

Three-fluid model is used to calculate the pressure drops in a vertical pipe with the annular flow pattern for condensing steam. The three-fluid models are based on the mass, momentum, and energy balance equations for each of the fluid streams in the annular flow. There are discrepancies between predictions of three-fluid model for pressure drops and the experimental data for pressure drops when using the available correlations for steam-film interfacial friction. The correlation by Stevanovic et al. provides good match with experimental data, but it does not take into account some important factors affecting the pressure drops in its three-fluid model. One of these significant factors which is considered in the three fluid model used in the present paper is virtual mass (added mass) force term. Inclusion of the virtual mass force improves the pressure drop predictions such that they agree much better with the experiments.
FORMATION AND IDENTIFICATION OF INTERSTELLAR MOLECULE LINEAR C5H FROM PHOTOLYSIS OF METHANE DISPERSED IN SOLID NEON

Photolysis of methane dispersed (1/1000) in solid Ne at 3 K with vacuum-ultraviolet light from a synchrotron produced infrared absorption lines of several products, including new lines at 3319.3 and 1955.5 cm−1. Based on experiments with isotopic labeling and results of quantum-chemical calculations, these lines are assigned to the C–H stretching and C=C stretching modes, respectively, of interstellar molecule linear C5H radicals.
Retrieval of the Green’s Function from Cross Correlation: The Canonical Elastic Problem

In realistic materials, multiple scattering takes place and average field intensities or energy densities follow diffusive processes. Multiple P to S energy conversions by the random inhomogeneities result in equipartition of elastic waves, which means that in the phase space the available elastic energy is distributed among all the possible states of P and S waves, with equal amounts in average. In such diffusive regimes, the P to S energy ratio equilibrates in a universal way independent of the particular details of the scattering. We study the canonical problem of isotropic plane waves in an elastic medium and show that the Fourier transform of azimuthal average of the cross correlation of motion between two points within an elastic medium is proportional to the imaginary part of the exact Green’s tensor function between these points, provided the energy ratio ES / EP is the one predicted by equipartition in two and three dimensions, respectively. These results clearly show that equipartition is a necessary condition to retrieve the exact Green’s function from correlations of the elastic field. However, even if there is not an equipartitioned regime and correlations do not allow to retrieve precisely the exact Green’s function, the correlations may provide valuable results of physical significance by reconstructing specific arrivals.
Vessel wall tracking based on the modified autocorrelation estimator

In 16 subjects (age 26-74) we recorded radio-frequency (RF) data of the Carotid artery with a Vivid7 scanner (GE Vingmed Ultrasound, Horten, Norway) and Carotid diameters with WallTrack (Pie Medical, Maastricht, The Netherlands). The RF data were stored as complex demodulated radio-frequency data (IQ data) and transferred to a PC for estimation of diameter curves. For the prototype system, diameter curves are derived using a modified autocorrelation method, in contrast to Walltrack where the complex cross-correlation method is applied. For all datasets, 2-5 beats were averaged to calculate representative one-cycle curves. The diameter distension /spl Delta/D as obtained with both systems was in the range 0.27-0.71 mm, and was highly correlated (r = 0.91, p < 0.002, y = 0.99x + 0.03) with a mean difference of -0.03 mm and limits of agreement (mean difference /spl plusmn/ 2*SD of the differences) of -0.15-0.09 mm. The relative distension /spl Delta/D/D ranged from 3.5 to 11.1% and had a correlation coefficient of r = 0.92 (p < 0.002, y = 0.94x + 0.75). The mean difference of /spl Delta/D/D was -0.4%, and the limits of agreement were -2.2-1.4%. In conclusion, this study indicates that it is adequate to use the modified autocorrelation method for vessel wall tracking.
A polarization-independent terahertz plasmon-induced transparency metamaterial based on hybrid graphene-gold structure for bio-sensing

A polarization-independent terahertz metamaterial based on hybrid graphene-gold structure with excellent refractive index sensing characteristics is proposed. The proposed structure exhibits a sharply narrow plasmon-induced transparency peak in the transmission spectrum at the terahertz regime. Obvious frequency shift in the transparency peak can be observed by varying the surrounding medium’s refractive index or the Fermi level in graphene, which can be well applied in bio-sensing technology. Moreover, an electrical RLC circuit model is used to provide a reasonable explanation for the optical response process in the proposed structure. Our work can offer reference value for the application of graphene technology as well as new idea for designing novel biosensors.
Windowed f-k spectra of a three-dimensional wavefield excited by a point source in a two-dimensional multilayered elastic medium

SUMMARY When full 3-D modelling is too costly or cumbersome, computations of 3-D elastic wave propagation in laterally heterogeneous, multilayered 2-D geological structures may enhance considerably our ability to predict strong ground motion for seismological and engineering purposes. Towards this goal, we extend the method based on the combination of the thin-layer finite-element and boundary-element methods (TLFE-BEM) and calculate windowed f -k spectra of the 3-D wavefield. The windowed f -k spectra are spatially localized spectra from which the local properties of the wavefield can be extracted. The TLFE-BEM is particularly suited for calculating the complete wavefield where surface waves are dominant in multilayered media. The computations are performed in the frequency domain, providing the f -k spectra directly. From the results for the 3-D wavefield excited by a point source in a 2-D multilayered, sloped structure, it can be said that the phase velocity of the fundamental-mode Rayleigh wave in a laterally heterogeneous multilayered medium, estimated from the windowed f -k spectra, varies with the location of the point source. For the model calculated in this article, the phase velocity varies between the value for the flat layered structure of the thick-layer side and that for the structure just under the centre of the window. The exact subsurface structure just under the centre of an array in a laterally heterogeneous medium cannot be obtained if we use the f -k spectral analysis assuming a flat layered structure.
Local Orientation Field Based Nonlocal Means Method for Fingerprint Image De-Noising

The de-noising of the fingerprint image is one of the key tasks before the extraction of the minutiae in automatic fingerprint matching. When used for de-noising the fingerprint image, the nonlocal means method can not preserve the local minutiae in the fingerprint image very well. To address this problem, we propose a local orientation field based nonlocal means (NLM-LOF) method in this paper. Experimental results on the simulated and real images show that the proposed method can suppress noise effectively while preserving edges and details in the fingerprint image and it outperforms the state-of-art nonlocal means method in terms of qualitative metrics and visual comparisons.
Before it's too late: a scientist's case for nuclear energy

I was not invited to write a foreword for this book. Dr. Cohen, knowing my busy schedule, would have considered such a request to be an imposition. I volunteered to do so in part to acknowledge my gratitude to him for having been a constant source of reference materials as I have turned my attention increasingly to informing both lay and scientific audiences concerning the biologic effects of low-level ionizing radiation. My primary reason for vol unteering, however, is to point to the importance of such a book for public education at a time when the media, in collaboration with a variety of activist groups, have developed among the people an almost phobic fear of radiation at any level. I take issue with the words of another Nobel laureate, George Wald, who states regularly "Every dose is an overdose. '" This philosophy has re sulted in women refusing mammography for the detection of breast cancer even though this methodology is the most sensitive for detection of such cancers in the early, curable stage, and even though, at present, breast cancer is the leading cause of cancer deaths among women. It has led a Westchester County, New York legislator to state proudly in the New York Times that he v vi I FOREWORD had introduced legislation that would bar all radioactivity from the county's roads. "
Spin-dependent scattering and the spin polarization of a diffusive current in partly disordered L10 epitaxial FePd

We report magnetic domain wall (DW) resistance in epitaxial films of FePd. When equal numbers of Fe and Pd atoms are present, this material forms an ordered structure with alternating crystal planes of Fe and Pd. We prepared films enriched with Pd to varying degrees, gradually degrading this structure. As might be expected, this increased the electrical resistivity of the films by introducing extra defects that can scatter electrons. However, unexpectedly, the additional resistance arising from the ∼10 nm thick DWs rose as a proportion of the overall resistivity, roughly doubling when halving the degree of chemical ordering—as determined from x-ray diffraction measurements—within the films. These data can be used to infer a rise in the spin polarization of the current flowing in the layers when extra Pd atoms are introduced. On the other hand, a separate measurement of spin polarization using a superconducting point contact technique that is insensitive to electron scattering revealed no changes as extra Pd was introduced. We conclude that Pd atoms scatter electrons of one spin far more strongly than the other, suggesting a possible means of producing highly spin-polarized currents for use in spintronic devices.
Thresholds of tone pitch contour discrimination for English listeners

This study aims to provide psychophysical data on English language listeners' ability to discriminate tone pitch contours. Just noticeable differences (JND) of F0 contour changes were measured in six native listeners of American English. Previous work in our lab found English listener thresholds for offsets of falling tones to be significantly lower than those for onsets of rising tones. To what extent this difference is due to the position of the F0 shift versus the direction of the F0 contour is unclear. In this study, we control for 4 experimental factors: stimulus type (speech, nonspeech), position of F0 shift (onset, offset), direction of shift (upward, downward), and F0 contour direction (falling, rising). Preliminary results reveal that English listeners had significantly lower psychophysical thresholds for F0 shifts at the offset than at the onset. No significant difference was found for F0 shift direction, F0 contour direction, or stimulus type. The current data suggests that the F0 shift position was the primary determinant in our previous study, and replicates other findings showing that English listeners perceive tones on a psychophysical base. Future work will examine these results in relation to those of native tone language listeners.
INCREASING PROTON POLARIZATION IN AGS AND RHIC

Polarized protons were accelerated in AGS and RHIC up to 100 GeV during the 2002 polarized proton run. We examined some of the major sources of depolarization in both the AGS and RHIC. In the AGS uncorrected depolarization due to weak intrinsic resonances and coupled spin resonances result in a net loss on the order of 40%. We studied in detail the responses of these resonances to tune, skew quadrupole strength and partial snake strength and compared them against predictions given by an enhanced version of DEPOL [1]. Three solutions to the remaining weak and coupled spin resonances in the AGS were examined. An 11.4% partial solenoidal snake successfully flipped the spin during an intrinsic resonance crossing, the first time a strong partial snake has been tested in this way. Next we re-examine the proposal to add a family of 12 quadrupoles to the 15th lattice location in the AGS [2] to suppress the weak intrinsic resonances and proposed the addition of a second family of six skew quadrupoles in the 15th location to suppress the coupled spin resonances. In RHIC higher order snake resonances were observed and measured for the first time. Their location and behavior appeared consistent with current snake resonance theory. Finally using the measured multipole fields along a fixed surface and current, a full field map was developed for RHIC’s Siberian snakes. These field maps were used to help control and calibrate the orbit and spin tune in RHIC.
Kinematic dynamo problem in a linear velocity field

A magnetic field is shown to be asymptotically (t → ∞) decaying in a flow of finite conductivity with v = Cr, where C = Cζ(t) is a random matrix. The decay is exponential, and its rate does not depend on the conductivity. However, the magnetic energy increases exponentially owing to growth of the domain occupied by the field. The spatial distribution of the magnetic field is a set of thin ropes and (or) layers.
The applications of fixed-point theorem in optimisation problems

The fixed-point theorem is widely used in different engineering applications. The present paper focuses on its applications in optimisation. A Matlab toolbox, which implements the branch-and-bound optimisation method based on the fixed-point theorem, is used for solving different real-life test problems, including estimation of model parameters for the Jiles-Atherton model.
Wavelet Filtering to Extract Coherent Vortices from Altimetric Data

Abstract Because of the optimal features of wavelet processing, the use of wavelets for describing and analyzing signals in 2D turbulence has been generalized since a decade ago. In spite of the close analogy between 2D turbulence and geophysical fluid dynamics, few works have tried to generalize the rich framework of wavelet techniques to the study of experimental signals in oceanography. In this paper, the authors extend a prominent wavelet technique designed for the study of direct numerical simulations (DNSs) on 2D turbulence, the coherent vortex simulation, and analyze with it ocean velocity fields obtained from sea surface height maps derived from satellite altimetry. The authors demonstrate the pertinence of this technique to describe altimetry data, resulting in a description of oceanic flows with a reduced number of degrees of freedom. In particular, it is shown that the western Mediterranean circulation is well approximated by a field of extracted coherent vortices when an appropriate wavelet ba.