Miracle-dz/UniFAR-FTUs huggingface dataset:
Star Formation and the Metallicity Aversion of Long-Duration Gamma-Ray Bursts

Abstract It has been suggested that the apparent bias of long-duration GRBs (LGRBs) to low metallicity environments might be a result of the fact that star-formation is anti-correlated with metallicity. However, if this were the cause, one would expect other indicators of star formation, such as Type II and Type Ic SNe to demonstrate a similar bias. Here we show that local Type Ic and Type II SNe track the star-formation weighted metallicity distribution of the SDSS galaxies. In contrast LGRBs are typically found at far-lower metallicities than would be expected based on the distribution of star-formation. This is true even when one takes into account so-called “dark bursts”. Indeed, while we will present data that show that some LGRBs form at very high metallicities, these objects enter the sample because of the large effective search volume produced by their bright hosts. The bias of LGRBs to low metallicity is real and must be related to a mechanism which is crucial in their formation.
Homogenized constitutive laws for rocks with elastoplastic fractures

This work deals with the development of a constitutive law for fractured rocks. Fractures are considered as penny‐shaped inclusions, whose constitutive law is deduced from an interface law and a regularization procedure. Such a method is applied to linear and non‐linear interface behaviours in order to reproduce effects such as an increase in stiffness during fracture closing, dilatancy or asperity surface degradation. Then, considering the fractured rock as a composite material, we use a Mori–Tanaka method to estimate the homogenized properties of the rock. Numerical experiments illustrate the interest of the proposed homogenization procedure. Copyright © 2007 John Wiley & Sons, Ltd.
Application of a Fault Detection and Isolation System on a Rotary Machine

The paper illustrates the design and the implementation of a Fault Detection and Isolation (FDI) system to a rotary machine like a multishaft centrifugal compressor. A model-free approach, that is, the Principal Component Analysis (PCA), has been employed to solve the fault detection issue. For the fault isolation purpose structured residuals have been adopted while an adaptive threshold has been designed in order to detect and to isolate the faults. To prove the goodness of the proposed FDI system, historical data of a nitrogen centrifugal compressor employed in a refinery plant are considered. Tests results show that detection and isolation of single as well as multiple faults are successfully achieved.
Theoretical Model for Estimation of Resonance Frequency of Rotational Circular Split-Ring Resonators

Absract In this article, a split-ring resonator with a rotated inner ring is analyzed for frequency tuning of the magnetic resonance of the split-ring resonator. Simulated results reveal an increase in the resonance frequency with an increasing angle between the splits. A simple theoretical model is proposed for accurate estimation of this resonance frequency for angular separation between the splits using simplified analytical formulations. The computed results using the proposed model are verified with simulated results. A close comparison between the present formulation and previously measured results for conventional circular split-ring resonators is also revealed.
High Conductivity of Mg-Doped Al0.3Ga0.7N with Al0.4Ga0.6N/AlN Superlattice Structure

The highly conductance of Mg-doped Al0.3Ga0. 7N layer using low-pressure metal organic chemical vapour deposition (MOCVD) on Al0.4Ga0. 6N/AlN superlattice structure was reported. The rapid thermal annealing (RTA) has been employed for the effective activation and generation of holes, and a minimum p-type resistivity of 3 Ω·cm for p-type Al0.3Ga0. 7N was achieved. The RTA annealing impacted on electrical, doping profile and morphological properties of Mg-doped Al0.3Ga0. 7N with Al0.4Ga0. 6N/AlN superlattice structure have been also discussed. The quality of Mg-doped Al0.3Ga0. 7N with Al0.4Ga0. 6N/AlN superlattice structure degraded after annealing from HRXRD. At appropriate annealing temperature and time, surface morphology of Mg-doped Al0.3Ga0. 7N can be improved. A step-like distribution of [Mg] and [H] in p-type Al0.3Ga0. 7N was observed, and thermal diffusion direction of [Mg] and [H] was also discussed.
Stein–Weiss inequalities for the fractional integral operators in Carnot groups and applications

In this article we consider the fractional integral operator I α on any Carnot group 𝔾 (i.e. nilpotent stratified Lie group) in the weighted Lebesgue spaces L p,ρ(x)β (𝔾). We establish Stein–Weiss inequalities for I α, and obtain necessary and sufficient conditions on the parameters for the boundedness of the fractional integral operator I α from the spaces L p,ρ(x)β (𝔾) to L q,ρ(x)−γ (𝔾), and from the spaces L 1,ρ(x)β (𝔾) to the weak spaces WL q,ρ(x)−γ (𝔾) by using the Stein–Weiss inequalities. In the limiting case , we prove that the modified fractional integral operator is bounded from the space L p,ρ(x)β (𝔾) to the weighted bounded mean oscillation (BMO) space BMOρ(x)−γ (𝔾), where Q is the homogeneous dimension of 𝔾. As applications of the properties of the fundamental solution of sub-Laplacian ℒ on 𝔾, we prove two Sobolev–Stein embedding theorems on weighted Lebesgue and weighted Besov spaces in the Carnot group setting. As another application, we prove the boundedness of I α from the weighted Besov spaces to .
Histogram equalization for noise-robust speech recognition using discrete-mixture HMMs

In this paper, we introduce a new method of robust speech recognition under noisy conditions based on discrete-mixture hidden Markov models (DMHMMs). DMHMMs were originally proposed to reduce calculation costs in the decoding process. Recently, we have applied DMHMMs to noisy speech recognition, and found that they were effective for modeling noisy speech. Towards the further improvement of noise-robust speech recognition, we propose a novel normalization method for DMHMMs based on histogram equalization (HEQ). The HEQ method can compensate the nonlinear effects of additive noise. It is generally used for the feature space normalization of continuous-mixture HMM (CMHMM) systems. In this paper, we propose both model space and feature space normalization of DMHMMs by using HEQ. In the model space normalization, codebooks of DMHMMs are modified by the transform function derived from the HEQ method. The proposed method was compared using both conventional CMHMMs and DMHMMs. The results showed that the model space normalization of DMHMMs by multiple transform functions was effective for noise-robust speech recognition.
Adhesive contact between a cylinder and a half-space

Numerical simulation for the adhesive contact between a sphere and a half-space is employed. The numerical simulation is performed for a realistic surface force law based on the Lennard-Jones potential between molecules with the Derjaguin approximation. The result is compared with the two-dimensional Maugis model, which uses the Dugdale law. It is found that the Maugis model gives good results, approximating those obtained by the numerical simulation. It is also found that the usual Maugis parameter governs the transition from the two-dimensional JKR model to the two-dimensional rigid cylinder contact. But the rigid body limit found using the Maugis model is different from that found using the numerical simulation.
Bragg gratings fabricated in monomode photosensitive optical fiber by UV exposure through a phase mask

A photolithographic method is described for fabricating refractive index Bragg gratings in photosensitive optical fiber by using a special phase mask grating made of silica glass. A KrF excimer laser beam (249 nm) at normal incidence is modulated spatially by the phase mask grating. The diffracted light, which forms a periodic, high‐contrast intensity pattern with half the phase mask grating pitch, photoimprints a refractive index modulation into the core of photosensitive fiber placed behind, in proximity, and parallel, to the mask; the phase mask grating striations are oriented normal to the fiber axis. This method of fabricating in‐fiber Bragg gratings is flexible, simple to use, results in reduced mechanical sensitivity of the grating writing apparatus and is functional even with low spatial and temporal coherence laser sources.
Clustering of the optical-afterglow luminosities of long gamma-ray bursts

Received 2005 Abstract. We studied the optical afterglows of the 24 pre-SWIFT Gamma-Ray Bursts with known spectroscopic redshift and published estimates of the optical extinction in the source frame. We find an unexpected clustering of the optical aft erglow luminosities measured 12 hours (source frame time) after the trigger. For 21 out of 24 bursts, the distribution of the opt ical luminosities is narrower than the distribution of the X-ray luminosities, and even narrower than the distribution of the ratio between the monochromatic optical luminosities and the total isotropic emitted prompt energy. Three bursts stand apart from the distribution of the other sources, being underluminous by a factor � 15. We compare this result with the somewhat analogous result concerning the luminosity of the X-ray afterglows studied by Gendre & Boer. For all our GRBs we construct the optical to X-ray spectral energy distribution. For all but a minority of them, the optical and the X-ray emissions are consistent with being produced by the same radiation process. We discuss our results in the framework of the "standard" external shock synchrotron model. Finally, we consider the behavior of the first GRBs of k nown redshifts detected by SWIFT. We find that these SWIFT GRBs entirely confirm our findings.
Truncation and Angular-Scattering Corrections for Absorbing Aerosol in the TSI 3563 Nephelometer

The nephelometer, the primary instrument used for accurate in-situ scattering measurements, suffers from small errors due to truncation and angular nonidealities in the light source. Because that error depends on particle size, it has been traditionally estimated from the wavelength dependence of scattering, which also depends on particle size. Absorption by particles alters the scattering wavelength dependence, so the traditional correction is in error by 1–5% for absorbing particles, particularly when that absorption is wavelength-dependent. Single-scattering albedos under 0.9 and absorption Ångström exponents above 2 can have errors of over 2%. This problem will occur only very near sources, including laboratory measurements of combustion aerosol. For these situations, we suggest the correction should be calculated using Mie theory and an assumed refractive index, resulting in less than a 2% error. Scattering wavelength dependence for absorbing particles should not be used as a measurement of particle size.
A turbulence model for magnetohydrodynamic plasmas

The statistical theory of inhomogeneous turbulence is applied to develop a system of model equations for magnetohydrodynamic (MHD) turbulence. The statistical descriptors of MHD turbulence are taken to be the turbulent MHD energy, its dissipation rate, the turbulent cross helicity (velocity-magnetic field correlation), turbulent MHD residual energy (difference between the kinetic and magnetic energies), and turbulent residual helicity (difference between the kinetic and current helicities). Evolution equations for these statistical quantities are coupled to the mean-field dynamics. The model is applied to two MHD-plasma phenomena: turbulence evolution with prescribed mean velocity and magnetic fields in the solar wind, and mean flow generation in the presence of a mean magnetic field and cross helicity in tokamak plasmas. These applications support the validity of the turbulence model. In the presence of a mean magnetic field, turbulence dynamics should be subject to combined effects of nonlinearity and Alfvén waves; consequences for the dissipation rate of MHD residual energy are discussed.
Power-law behaviors from the two-variable Langevin equation: Ito’s and Stratonovich’s Fokker–Planck equations

We study the power-law behaviors generated from the stochastically dynamical system governed by the well known two-variable Langevin equations. The stationary solutions of the corresponding Ito, Stratonovich and Zwanzig (backward Ito) Fokker–Planck equations are solved under a new fluctuation–dissipation relation; they are presented in a unified form of the power-law distributions with a power index containing two parameters κ and σ, where κ measures the distance away from thermal equilibrium and σ distinguishes the above three forms of the Fokker–Planck equations. The numerical calculations show that the Ito, the Stratonovich and the Zwanzig forms of the power-law distributions are all exactly the stationary solutions based on the two-variable Langevin equations.
ANALYSIS OF NARROW AND BROAD PROFILES OBSERVED FOR THE λ6614 DIFFUSE INTERSTELLAR BAND

We present an analysis of the diverse spectral profiles observed for the λ6614 diffuse interstellar band (DIB). This includes the anomalous Herschel 36 profile, exhibiting a prominent, broad red tail, and the typically observed narrow profiles, exhibiting much narrower, but noticeable red tails. This study was motivated by the inability of previous rotational contour modeling work to account for the narrow and broad red tails. We show that the full profiles, for all the observations, can consistently be modeled as a superposition of two overlapping DIBs, with peaks at 6613.6 and 6614.2 Å. Each DIB is plausibly fit using a prolate, parallel band, symmetric top spectral contour model. For λ6613.6, there are small differences in the rotational constants, less than 1%, between the upper and lower transition states; whereas, for λ6614.2, the differences are much larger, ∼ −5%. These results are consistent with λ6614.2 being the source of the narrow and broad red tails. The fit residuals are shown to be consistent with contributions from overlapping spectra, attributed to closely spaced vibrational sequences, originating from low frequency vibrations. We suggest that such sequences may be the source of the anomalous broadening needed to obtain good spectral fits to narrow DIB profiles. We discuss how λ6614.2 and the other Herschel 36 extended red tail DIBs help bridge the association gap between the narrow, absorption DIBs and the even broader and more redshifted emission features observed for the Red Rectangle. Finally, the broader implications of this study, in the context of identifying DIB molecular carriers, are discussed.
Stability analysis of event-triggered networked control systems with time-varying delay

Networked control systems(NCSs) are facing a great challenge from the limitation of network communication resources. Event-triggered control (ETC) is often used to reduce the amount of communications while still keeping a satisfactory performance of the system, by transmitting the state measurements only when an event-triggered condition is met. However, some network-induced problems would happen inevitably, such as communication delay. The delay can degrade the control performance significantly and can even lead to instability. In this paper, we study an NCS considering both ETC and time-varying delay, which is rare in the literature. We formulate the system as a discretized piecewise linear system with exponential uncertainty. Then the model is embedded in a polytopic approximation with better structure suitable for stability analysis. Stability conditions are derived in terms of linear matrix inequalities (LMIs). Finally, the developed method is illustrated by a numerical example.
Rigorous Evaluation of Ohmic-Loss Effects for Accurate Design of Traveling-Wave Antennas

In this work, the effects of the ohmic losses on the radiation properties are extensively evaluated for the general class of the traveling-wave antennas. For arbitrary aperture distributions, rigorous analytical approaches have been developed to take into account the dissipation in conductors and/or dielectrics that can adversely affect the basic design parameters, such as efficiency and leakage constant. Consequently, fundamental information is achieved both to quantify the alterations in the antenna performances due to misappreciation of the ohmic losses and, above all, to appropriately correct the synthesis procedures for improved radiation patterns. Important applications of this analysis refer to topologies of leaky-wave antennas.
Recent progress in development and nonlinear optical device application of optical fibers incorporated with noble metal nanoparticles

Recent progress in development and nonlinear optical device application of germano-silicate optical fibers incorporated with noble metal nanoparticles are presented. Novel macro-optical properties, such as linear absorption, resonant optical nonlinearity, and optical limiting properties of the fibers fabricated by modified chemical vapor deposition and solution doping techniques are experimentally and theoretically demonstrated based on surface plasmon resonance effect and nonlinear confinement of the noble metal nanoparticles. Applications of the fibers for all-optical signal gating with the cascaded long period gratings and for a new method to determine the third-order susceptibility of optical fibers are discussed.
A special case of Neumann's system and the Kowalewski-Chaplygin-Goryachev top

The authors present L operators both for the special case of Neumann's system and the Kowalewski-Chaplygin-Goryachev top. These are quantum systems integrable by the quantum inverse scattering (R-matrix) method. L operators, being 2*2 matrices, satisfy an algebra generated by an R matrix of the XXX type. The close connection between the two models is demonstrated. They carry out a non-obvious separation of variables and also give a dynamical group scheme for the eigenstate problem of Neumann's system. This separation differs from those in Euler angles and allows them to find eigenenergies in an effective way.
Applications of the Lambert W function to analyze digital camera sensors

The Lambert W function is applied via Maple to analyze the operation of the modern digital camera sensors. The Lambert W function had been applied previously to understand the functioning of diodes and solar cells. The parallelism between the physics of solar cells and digital camera sensors will be exploited. Digital camera sensors use p-n photodiodes and such photodiodes can be studied using the Lambert W function. At general, the bulk transformation of light into photocurrent is described by an equivalent circuit which determines a dynamical equation to be solved using the Lambert W function. Specifically, in a camera senor, the precise measurement of light intensity by filtering through color filters is able to create a measurable photocurrent that is proportional to image point intensity; and such photocurrent is given in terms of the Lambert W function. It is claimed that the drift between neighboring photocells at long wavelengths affects the ability to resolve an image and such drift can be represented effectively using the Lambert W function. Also is conjectured that the recombination of charge carries in the digital sensors is connected to the notion of “noise” in photography and such “noise” could be described by certain combinations of Lambert W functions. Finally, it is suggested that the notion of bias, and varying the width of the depletion zone, has a relationship to the ISO “sped· of the camera sensor; and such relationship could be described using Lambert W functions.
Models for Variable-Stress Accelerated Life Testing Experiments Based on Wiener Processes and the Inverse Gaussian Distribution

Variable-stress accelerated life testing trials are experiments in which each of the units in a random sample of units of a product is run under increasingly severe conditions to get information quickly on its life distribution. We consider a fatigue failure model in which accumulated decay is governed by a continuous Gaussian process W(y) whose distribution changes at certain stress change points to < t l < < … <t k , Continuously increasing stress is also considered. Failure occurs the first time W(y) crosses a critical boundary ω. The distribution of time to failure for the models can be represented in terms of time-transformed inverse Gaussian distribution functions, and the parameters in models for experiments with censored data can be estimated using maximum likelihood methods. A common approach to the modeling of failure times for experimental units subject to increased stress at certain stress change points is to assume that the failure times follow a distribution that consists of segments of Weib.
Focused Information Criterion and Model Averaging in Quantile Regression

In this article, we study model selection and model averaging in quantile regression. Under general conditions, we develop a focused information criterion and a frequentist model average estimator for the parameters in quantile regression model, and examine their theoretical properties. The new procedures provide a robust alternative to the least squares method or likelihood method, and a major advantage of the proposed procedures is that when the variance of random error is infinite, the proposed procedure works beautifully while the least squares method breaks down. A simulation study and a real data example are presented to show that the proposed method performs well with a finite sample and is easy to use in practice.
An effective field theory model for differential elliptic cohomology at the Tate curve

We construct a model for differential elliptic cohomology at the Tate curve whose cocycles are families of 2-dimensional effective supersymmetric field theories. A geometrically-motivated modularity condition requires partition functions to take values in TMF with complex coefficients. Cocycles satisfying this condition yield classes in a 24-periodic differential cohomology theory whose coefficients are the ring of integral modular forms. We construct examples of cocycles from families of string manifolds and principal bundles with structure group the monster.