Miracle-dz/UniFAR-FTUs huggingface dataset:
Model Selection via Bayesian Information Criterion for Quantile Regression Models

Bayesian information criterion (BIC) is known to identify the true model consistently as long as the predictor dimension is finite. Recently, its moderate modifications have been shown to be consistent in model selection even when the number of variables diverges. Those works have been done mostly in mean regression, but rarely in quantile regression. The best-known results about BIC for quantile regression are for linear models with a fixed number of variables. In this article, we investigate how BIC can be adapted to high-dimensional linear quantile regression and show that a modified BIC is consistent in model selection when the number of variables diverges as the sample size increases. We also discuss how it can be used for choosing the regularization parameters of penalized approaches that are designed to conduct variable selection and shrinkage estimation simultaneously. Moreover, we extend the results to structured nonparametric quantile models with a diverging number of covariates. We illustrate our theoretical results via some simulated examples and a real data analysis on human eye disease. Supplementary materials for this article are available online.
Consistency of continual reassessment method under model misspecification

SUMMARY This paper studies large sample behaviour of the continual reassessment method used to determine the target dose levels in phase I clinical trials. A sequential maximum likelihood procedure is investigated for local estimation of a given targeted toxicity level. Consistency and asymptotic normality for the maximum likelihood estimates are established under model misspecification and it is shown that, in general, the recommended dose level will converge to the target level. There are, however, situations in which the recommended dose may converge to a level close to the target level, but not necessarily the closest. This contrasts with the conclusions of O'Quigley, Pepe & Fisher (1990) and we describe this situation as well as providing the conditions under which convergence is assured.
Near-field enhanced imaging by a magnetized ferrite slab

This letter demonstrates the near-field imaging enhancement at microwave frequencies of two-dimensional sources by a ferrite slab magnetized to saturation. It is shown that this effect is based on the nonreciprocal amplification of magnetostatic surface waves (MSSW) across the ferrite slab. The inclusion of losses in our analysis has also made it possible to prove this effect for realistic yttrium iron garnet ferrite samples. For ferrite slabs of width d, the resolution at the image plane (at a distance 2d from the source) is better than the resolution in air at a distance d of the source, which leads to an equivalent air length of the ferrite slab less than zero. Since the constitutive parameters of saturated ferrites depend on the external magnetizing field, the operation frequency of the proposed imaging devices can be tuned by varying this biasing field.
Comment on “Observation of long‐duration gyroharmonic resonances: A refutation of the short‐duration explanation for interpreting the anomalous URAP sounder spectra observed in the Io torus” by P. Canu

Canu [2001] presented observations from the GEeS 1, GEeS 2, and ISEE 1 relaxation sounders to argue against the conclusions of Benson et al. [1997] permining to the interpretation of the plasma resonances stimulated by the Ulysses Unified Radio and Plasma Wave (URAP) relaxation sounder in Jupiter's Io plasma toms. He also argued that his observations provided support for the interpretation of these resonances offered by LeSager et al. [1998] rather than the original interpretation of Osherovich et al. [1993]. These studies are important to our understanding of the Io plasma toms because fundamental questions remain concerning the generation mechanisms for these resonances, which have been used to determine the ambient electron density Ne from the deduced electron plasma frequency fpe (fv in ionospheric topside sounder notation) and the absolute value of the magnetic field B from the deduced electron gyrofrequency ice (fH in ionospheric topside sounder notation). A proper understanding of the generation mechanism for these resonances may also be relevant to similar diagnostic applications in the terrestrial magnetosphere. In this regard, additional evidence has been presented that the diagnostics can be based on narrowband magnetospheric emissions, stimulated by natural processes, using scaling laws derived from investigations of ionospheric emissions, with similar frequency spectra, that are stimulated by high-power topside sounders [Benson et al., 2001].
Visible Light Emission and Microplasma Phenomena in Silicon p-n Junction, I.

Experimental results on the visible light emission and microplasma phenomena in silicon p – n junction are described. It has been found that the microplasma spot in the p – n junction can be located by scanning small chopped light spot on the junction surface. Combining this method of location of the microplasma spot and the observation by microscope, it is concluded that the light emitting spot does not necessarily coincide with the microplasma spot. Possibility of the effect of impurities on the light-emitting phenomena is discussed briefly in connection with our recent experimental result on the visible light emission from germanium p – n junction. A simple model of p – n junction is proposed for the understanding of microplasma phenomenon.
Downstream instabilities of electronegative plasma discharges

Relaxation oscillations are observed in low-pressure inductive plasma discharges operated with argon and SF6 gas mixtures. The data suggest that instabilities may develop periodically at some downstream location. Linear fluid and kinetic calculations predict ion two-stream instabilities when the positive and negative ions develop sufficiently large drift velocities of opposite sign in the downstream region. The thresholds and the growth rates of the instabilities are calculated and are found in fair agreement with the observations. The instability models can explain several key experimental features.
Relative Equilibria of the Curved N-Body Problem

Introduction. - Preliminary developments. - Equations of motion. - Isometric rotations. - Relative equilibria (RE). - Fixed Points (FP). - Existence criteria. - Qualitative behavior. - Positive elliptic RE. - Positive elliptic-elliptic RE. - Negative RE. - Polygonal RE. - Lagrangian and Eulerian RE. - Saari's conjecture.
A Jet Associated with the Classical T Tauri Star RY Tauri

High spatial resolution images have been taken on the Gemini North telescope of the classical T Tauri star RY Tauri. The Hα image, with the continuum properly subtracted, shows a jet extending out to at least 31″ at a position angle of about 295° from the star. A counterjet extending to at least 3.5′ in the opposite direction is also visible. The knots in the inner part of the jet are probably less than 10 years old. This new Herbig-Haro bipolar jet has been labeled HH 938. Comparison with previous Hubble Space Telescope (HST) images revealed a probable tangential motion of the brightest knot by about 165 km s−1. The orientation of the disk, as given by the average position angle of published polarization measurements, is ≈20°, or almost perpendicular to the direction of the jet. Because of the proximity of its inner knots to the star and their very young dynamical age, this jet is a very good candidate to study jet emission mechanisms.
Optimum simple step-stress accelerated life-tests with competing causes of failure

Optimum simple step-stress accelerated life tests (ALTs) for products with competing causes of failure are presented. The life distribution of each failure cause, which is independent of the others, is assumed to be exponential with a mean that is a log-linear function of the stress, and a cumulative exposure model is assumed. Optimum plans for time-step and failure-step ALTs are obtained which minimize the sum over all failure causes of asymptotic variances of the maximum likelihood estimators of the log mean lives at design stress. The competing causes of failure affect the optimum test plan only through the product of two ratios-the ratio of the sums of the mean lives and the ratio of the sums of the failure rates over all failure causes at low and high stress levels. The effect of this product (of two ratios) is studied. >
Standard Errors of Equipercentile Equating for the Common Item Nonequivalent Populations Design

An equating design in which two groups of examinees from slightly different populations are administered different test forms that have a subset of items in common is widely used. A procedure for equipercentile equating under this design has been previously outlined, but standard errors for this rather complex procedure have not been provided. This paper provides these standard errors and a simulation that verifies the equations for large samples. A real data example is provided for considering issues involved in using these procedures.
Enhanced exciton separation through negative energy band bending at grain boundaries of Cu2ZnSnSe4 thin-films

Local surface potential of Cu2ZnSnSe4 thin-films was investigated by Kelvin probe force microscopy. The surface potential profile across grain boundaries (GBs) shows a rise of 200–600 meV at GBs in a Cu-poor and Zn-poor film with 3.8% efficiency, which means positively charged GBs. In contrast, the GBs in a Cu-poor and Zn-rich film with 2% efficiency exhibit lowering of surface potential by 40 meV. The results indicate that GBs of Cu2ZnSnSe4 films play a role for exciton separation and governing defects for high efficiency could be not only CuZn but also VCu as explained theoretical predictions.
An Experimental Investigation of Viscoelastic Flow past a Circular Cylinder

The drag forces of circular cylinders of infinite or finite span are examined in both Newtonian fluids and dilute polymer solutions. Using some circular cylinders with different ratios of length(l) to diameter(d), the drag forces in the Re range of 1 to 5×104 and the pressure distributions in the Re range of 1.7×104 to 5×104 are measured. The results make it clear that (l) the drag forces decrease at Re 20 with an increase of l/d, (2) the drag forces for dilute polymer solutions reduce more than those for Newtonian fluids at Re< 1×108.
Oscillation regimes of the internal kink mode in tokamak plasmas

The long-term dynamics of the internal kink mode are studied using the non-linear, two-fluid magnetohydrodynamics (MHD) code XTOR-2F (Lütjens et al 2010 J. Comput. Phys. 229 8130). The dynamics of the internal kink are studied in resistive MHD plus transport, and, in addition, also including some two-fluid effects. The simulation results yield a pattern of kink cycles or stationary states with m/n = 1/1 helicity. The threshold for sustained (non-decaying) kink cycles, which characterize sawtooth oscillations, is shown to depend on the plasma pressure, the current and energy diffusion times, and the ion and electron diamagnetic drifts. In particular, the diamagnetic flow stabilization extends the cyclic kink regime into a parameter space that is adequate to carry out studies of sawtooth oscillations in ohmic tokamak discharges.
Error Estimates with Sharp Constants for a Fading Memory Volterra Problem in Linear Solid Viscoelasticity

The problem characterizing nonageing linear isothermal quasi-static isotropic compressible solid viscoelasticity in the time interval [0,T] is described. This is essentially a Volterra equation of the second kind arrived at by adding smooth fading memory to the elliptic linear elasticity equations. We analyze the errors resulting from replacing the relaxation functions with practical approximations, in a semidiscrete finite element approximation, and in a fully discrete scheme derived by replacing the hereditary integral with the trapezoidal rule for numerical integration. The error estimates are sharp in the sense that if certain bounds on the data are independent of T, then so also are the constants involved in them. This is a consequence of bypassing the usual Gronwall lemmas with arguments that are more sensitive to the fading memory of the physical problem.
Selection of Variables in Discriminant Analysis by F-statistic and Error Rate

Five programs for selection of variables in discriminant analysis are compared: the program DISCRIM of McCabe [8]. the BMD07M program, see Dixon [1], the program ALLOC-I of Habhema, Hermana and van den Broek [3], and two more recent programs: SPSS and BMDP7M, see Nie e.a. [10] and Dixon [2]. Emphasis is on the criteria for selection and on the distributional assumptions involved. The programs are compared experimentally using two examples: one with real data, also used by McCabe [8], and one with simulated data.
Isotope shifts and hyperfine structure of 134-138Ba II by fast ion beam-laser spectroscopy

We have measured the isotope shifts of the 5d to 6p transitions in 134-138Ba II, of which the 5d3/2 to 6p1/2 transition has not been measured earlier. We have also obtained values with improved accuracy of the magnetic dipole and electric quadrupole hyperfine coupling constants of the 6p 2Po1/2,3/2 levels in 135,137Ba II. The measurements are performed in the red and orange parts of the optical spectrum using fast ion beam-laser spectroscopy with an improved procedure which avoids calibration of the ion velocity. A comparison with theory is made.
Large-Field CO (J = 1→0) Observations of the Starburst Galaxy M 82

We present large-field (15.7 16.9 arcmin) CO (J = 1! 0) observations of the starburst galaxy M 82, at an angular resolution of 2200 with the NRO 45-m telescope. The CO emission was detected in the galactic disk, outflow (driven by the galactic wind) up to 2 kpc above the galactic plane in the halo, and in tidal streams. The kinematics of the outflow (including CO line splitting) suggests that it has the shape of a cylinder that is diverging outwards. The mass and kinetic energy of the molecular gas outflow are estimated to be (0.26–1.0) 10 Mˇ and (1–4) 10 erg. A clump of CO gas was discovered 3.5 kpc above the galactic plane; it coincides with a dark lane previously found in X-ray observations, and a peak in H I emission. A comparison with H I, hot molecular hydrogen and dust suggests that the molecular gas shows signatures of warm and cool components in the outflow and tidal streams, respectively.
Splashing of water drops on solid and wetted surfaces: hydrodynamics and charge separation

The charges separated by splashes on solid and wetted surfaces are shown to be carried on the liquid fragments ejected from the crown. Experimental observations on the nature of these splashes are presented and mechanisms for the formation and break-up of the crown are proposed. The surface on which a splash occurs is generally left with a positive charge, the magnitude of which decreases with increasing concentration of solute in the drop. This is explained by the disruption of the electrical double layer. When drops containing ammonium hydroxide in excess of 2.5 x 10-5 mol 1_1 splash on ice at — 1 °C the ice receives a positive charge. In this case, freezing potentials appear to play a role in the charging. In an applied electric field the charges separated by splashing increase as the field is increased, in agreement with an induction mechanism of charging. Also, in an applied electric field, the charges initially increase as the impact speed is increased but beyond a certain impact speed the charges decrease. This is explained in terms of the relative magnitudes of the time of contact of the ejected liquid fragments with the crown and the relaxation time of charge carriers in the liquid. The role of charge separation due to splashing in thunderstorm electrification and in the build-up of space charges during rainfall is discussed.
Binocular depth perception of computer-generated patterns

The perception of depth involves monocular and binocular depth cues. The latter seem simpler and more suitable for investigation. Particularly important is the problem of finding binocular parallax, which involves matching patterns of the left and right visual fields. Stereo pictures of familiar objects or line drawings preclude the separation of interacting cues, and thus this pattern-matching process is difficult to investigate. More insight into the process can be gained by using unfamiliar picture material devoid of all cues except binocular parallax. To this end, artificial stereo picture pairs were generated on a digital computer. When viewed monocularly, they appear completely random, but if viewed binocularly, certain correlated point domains are seen in depth. By introducing distortions in this material and testing for perception of depth, it is possible to show that pattern-matching of corresponding points of the left and right visual fields can be achieved by first combining the two fields and then searching for patterns in the fused field. By this technique, some interesting properties of this fused binocular field are revealed, and a simple analog model is derived. The interaction between the monocular and binocular fields is also describea. A number of stereo images that demonstrate these and other findings are presented.
Equating Methods and Sampling Designs

The equating methods used and sampling designs employed by the empirical studies in this special issue are described in this introductory article. This theoretical article sets the stage for the empirical articles that follow by introducing the methods and designs and by relieving subsequent authors of the need to spend much time describing either the methods or sampling designs. Four requisites for equating are listed and the invariance of equating functions requisite is identified as the focus of this special issue. Descriptions are given of the Tucker linear equating method, the Levine equally reliable and unequally reliable linear equating methods, the chained equipercentile equation method, the frequency estimation equipercentile and linear equating methods, and the 3PL item response theory true-score equating method. All these methods employ data collected within an anchor test design. The description of each method focuses on assumptions made by that method, may include some basic mathematical expr.
Self-similar condensation of spherically symmetric self-gravitating isothermal gas clouds

The authors show that similarity solutions for the condensation of spherically symmetric self-gravitating isothermal gas clouds are much more abundant than was hitherto believed; they have discovered that each of the discrete solutions found by previous authors must be replaced by a bounded two-parameter continuum of such solutions. Moreover, the two parameters (z0, w0) admit a clear and useful physical interpretation. z0 characterizes the asymptotic form of a solution as t→-∞ (i.e. at very early times), and reflects how intrinsically unstable against contraction the cloud interior is from the outset. w0 characterizes the asymptotic form of a solution as t→+∞ (i.e. at very late times) and reflects how important external pressure is in driving compression. The evolution of the flow is presented and discussed.
The Optical Counterpart of M101 ULX-1

We have identified the optical counterpart of the ultraluminous X-ray source M101 ULX-1 (CXOKM101 J140332.37+542102), by comparing Hubble Space Telescope Advanced Camera for Surveys images with Chandra ACIS-S images. The optical counterpart has V = 23.75 and colors consistent with those for a mid-B supergiant. Archival Wide Field Planetary Camera 2 observations show that the source brightness is constant to within ~0.1 mag. The physical association of this source with the ULX is confirmed by Gemini Multi-Object Spectrograph observations that show spatially unresolved He II λ4686 and He I λ5876 emission. These results suggest that M101 ULX-1 is a high-mass X-ray binary, but deep spectroscopic monitoring observations are needed to determine the detailed properties of this system.
A simple analytical model for dynamics of time-varying target leverage ratios

Abstract In this paper we have formulated a simple theoretical model for the dynamics of the time-varying target leverage ratio of a firm under some assumptions based upon empirical observations. In our theoretical model the time evolution of the target leverage ratio of a firm can be derived self-consistently from a set of coupled Ito’s stochastic differential equations governing the leverage ratios of an ensemble of firms by the nonlinear Fokker-Planck equation approach. The theoretically derived time paths of the target leverage ratio bear great resemblance to those used in the time-dependent stationary-leverage (TDSL) model [Hui et al., Int. Rev. Financ. Analy. 15, 220 (2006)]. Thus, our simple model is able to provide a theoretical foundation for the selected time paths of the target leverage ratio in the TDSL model. We also examine how the pace of the adjustment of a firm’s target ratio, the volatility of the leverage ratio and the current leverage ratio affect the dynamics of the time-varying target leverage ratio. Hence, with the proposed dynamics of the time-dependent target leverage ratio, the TDSL model can be readily applied to generate the default probabilities of individual firms and to assess the default risk of the firms.
Stability analysis of a boundary layer over a hump using parabolized stability equations

Parabolized stability equations (PSEs) were used to investigate the stability of boundary layer flows over a small hump. The applicability of PSEs to flows with a small separation bubble was examined by comparing the result with DNS data. It was found that PSEs can efficiently track the disturbance waves with an acceptable accuracy in spite of a small separation bubble. A typical evolution scenario of Tollmien–Schlichting (TS) wave is presented. The adverse pressure gradient and the flow separation due to the hump have a strong effect on the amplification of the disturbances. The effect of hump width and height is also examined. When the width of the hump is reduced, the amplification factor is increased. The height of the hump is found to obviously influence the stability only when it is greater than the critical layer thickness.
NNIL, A study in intuitionistic propositional logic

In this paper we study NNIL, the class of formulas of the Intuitionistic Propositional Calculus. IPC with no nestings of implications to the left. We show that the formulas of this class are precisely the formulas of the language of IPC that are preserved under taking submodels of Kripke models for IPC (for various notions of submodel). This makes NNIL an analogue of the purely universal formulas in Predicate Logic. We prove a number of interpolation properties for NNIL, and explore the extent to which these properties can be generalized to more complicated classes of formulas.
A Catalog of Parameters for Globular Clusters in the Milky Way

A database of parameters for globular star clusters in the Milky Way is described which is available in electronic form through the WorldWideWeb. The information in the catalog includes up-to-date measurements for cluster distance, reddening, luminosity, colors and spectral types, velocity, structural and dynamical parameters, horizontal branch morphology, metallicity, and other quantities. This catalog will be updated regularly and maintained in electronic form for widest possible accessibility. Associated Articles Source Paper Catalog Description Catalog Description
SELF-CONTROL IN SPARSELY CODED NETWORKS

A complete self-control mechanism is proposed in the dynamics of neural networks through the introduction of a time-dependent threshold, determined in function of both the noise and the pattern activity in the network. Especially for sparsely coded models this mechanism is shown to considerably improve the storage capacity, the basins of attraction and the mutual information content of the network.