Miracle-dz/UniFAR-FTUs huggingface dataset:
X-ray variability of NGC 3227 and 5506 and the nature of active galactic nucleus ‘states’

We use X-ray monitoring data obtained over a broad range of time-scales to measure the broad-band power spectral density functions (PSDs) of two Seyfert galaxies: the broadline Seyfert 1 NGC 3227 and the Seyfert 2 NGC 5506, which has recently been identified as an obscured narrow-line Seyfert 1 (NLS 1). Using a Monte Carlo fitting technique, we demonstrate that both PSDs are reminiscent of the PSD of black hole X-ray binaries (BHXRBs) in the high/soft state, and specifically rule out a low/hard-state PSD shape in NGC 3227. This result demonstrates that, at least where variability is concerned, broad-line Seyferts with hard X-ray spectra (photon index � ∼ 1.6) are not simply the analogues of the low/hard state in BHXRBs, and the dichotomy of NLS 1 and broad-line Seyferts cannot be simply interpreted in terms of the two states. We show that the PSD normalization in NGC 3227 is strongly energy-dependent, with larger variability amplitudes at lower energies, unlike NGC 5506 which shows little energy dependence of variability. We demonstrate that this difference is caused by spectral pivoting of the continuum in NGC 3227 at high energies, which is probably also related to the large amplitude of variability seen in the 2‐10 keV band in this active galactic nucleus (AGN). Using the new PSD data and new results in the literature, we replot the PSD break time-scale versus mass plot for all AGNs with PSD breaks measured so far, and demonstrate that higher accretion rate AGNs appear to have relatively shorter break time-scales for their black hole mass than lower accretion rate AGNs. Ke yw ords: methods: statistical ‐ galaxies: active ‐ galaxies: individual: NGC 3227 ‐ galaxies: individual: NGC 5506 ‐ galaxies: Seyfert ‐ X-rays: galaxies.
Relative and Tate homology with respect to semidualizing modules

We introduce and investigate in this paper a kind of Tate homology of modules over a commutative coherent ring based on Tate ℱC-resolutions, where C is a semidualizing module. We show firstly that the class of modules admitting a Tate ℱC-resolution is equal to the class of modules of finite 𝒢(ℱC)-projective dimension. Then an Avramov–Martsinkovsky type exact sequence is constructed to connect such Tate homology functors and relative homology functors. Finally, motivated by the idea of Sather–Wagstaff et al. [Comparison of relative cohomology theories with respect to semidualizing modules, Math. Z. 264 (2010) 571–600], we establish a balance result for such Tate homology over a Cohen–Macaulay ring with a dualizing module by using a good conclusion provided in [E. E. Enochs, S. E. Estrada and A. C. Iacob, Balance with unbounded complexes, Bull. London Math. Soc. 44 (2012) 439–442].
Helium flashes and hydrogen mixing in low-mass population III stars

A one solar mass, zero-metal star is evolved through the peak of the major core helium flash and compared with models for which the metal abundance is Z = 0.0001 and 0.02. Before central hydrogen is exhausted, and long before the major core helium flash occurs, the Z = 0 model experiences a helium-burning thermal runaway at the center. As this model evolves along the giant branch, recurrent helium-burning thermal runaways are initiated at the base of the hydrogen-burning shell. The thermal structure of the electron-degenerate core of the Z = 0 red giant is completely different from that of the higher Z red giants. As a result of this structure, the major flash begins at a location much farther from the center than in the higher Z cases. Most significantly, during the flash in the Z = 0 model, the outer edge of the convective shell formed in the helium zone extends into layer containing hydrogen, which does not occur in the Z = 0.0001 or Z = 0.02 cases. 61 refs.
Comparison of ANOVA-F and ANOM tests with regard to type I error rate and test power

A Monte Carlo simulation was conducted to compare the type I error rate and test power of the analysis of means (ANOM) test to the one-way analysis of variance F-test (ANOVA-F). Simulation results showed that as long as the homogeneity of the variance assumption was satisfied, regardless of the shape of the distribution, number of group and the combination of observations, both ANOVA-F and ANOM test have displayed similar type I error rates. However, both tests have been negatively affected from the heterogeneity of the variances. This case became more obvious when the variance ratios increased. The test power values of both tests changed with respect to the effect size (Δ), variance ratio and sample size combinations. As long as the variances are homogeneous, ANOVA-F and ANOM test have similar powers except unbalanced cases. Under unbalanced conditions, the ANOVA-F was observed to be powerful than the ANOM-test. On the other hand, an increase in total number of observations caused the power values of ANOVA-F and ANOM test approach to each other. The relations between effect size (Δ) and the variance ratios affected the test power, especially when the sample sizes are not equal. As ANOVA-F has become to be superior in some of the experimental conditions being considered, ANOM is superior in the others. However, generally, when the populations with large mean have larger variances as well, ANOM test has been seen to be superior. On the other hand, when the populations with large mean have small variances, generally, ANOVA-F has observed to be superior. The situation became clearer when the number of the groups is 4 or 5.
Novel adaptive phase-shifting interferometry

An adaptive phase-shifting interferometry, insensitive to the disturbance of constant term of phase perturbations induced by environmental vibration and air turbulence is introduced. Where high frequency intensity modulation of laser beam and phase lock-in as well as the closed loop control techniques are used. The wobble of interference fringes can be compensated, and sequentially be locked at arbitrarily chosen phases for phase-shifting testing. Comparing with other similar techniques, here the depth of signal modulation is not limited by the magnitude of optical path difference (OPD) and the fringe contrast is not reduced by the modulation, hence a high SNR can be obtained. The experimental results and conclusions are presented.
Resonance fluorescence of ladder- and triangular-type three-level systems: Continuous coherent photon generation

We theoretically investigate resonance fluorescence of a ladder- and a triangular-type three-level atomic system in the full quantization regime. By solving Heisenberg’s quantum kinetic equations of motion of an electron interacting with photons and two coherent laser fields, we obtain the firstorder electric field correlation function, which corresponds to photoluminescence spectrum. When the single electrons in both systems are resonantly excited by two strong cw-laser fields, in contrast to the ladder-type atomic systems emitting mainly incoherent photons, the triangular-type system shows that continuous coherent photons can be selectively generated from three optical transitions by trapping electronic population inversions and manipulated by changing the transition rates.
Distributed leader‐follower flocking control

This paper presents a fuzzy based leader‐follower flocking system. To maintain the distance between robots, we use a fuzzy logic controller to design a “force function” which is related to the relative distance between neighbours. The “force function” is used to control velocity of robots. To prove stability of the flocking system, we build a Hamilton function which is kinetic energy of the flocking system. Utilizing the LaSalle's invariance principle, we prove that the system is stable. Specially, we develop a flocking controller in local form. By using the local controller, the robots in the flocking system only need to know local information (relative distances and relative angles between neighbours). To evaluate performance of the flocking system, we simulate the flocking system tracking trajectories with different shapes. The local flocking algorithm is tested with three Pioneer robots. We use the SICK laser scanner to measure the relative distances and relative angles between neighbours. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Research on an Improved CHI Feature Selection Method

In order to make the features selected are distributed intensively in a certain class ,evenly in that certain class as much as possible, and make features appear in that certain class as many as possible , three adjusted parameters are added to the originally traditional CHI-square feature selection method through analyzing the relevance between features and classes. Var-CHI statistic method based on variance makes the precision and recall improved apparently by comparing the experiments of the traditional CHI-square feature selection method and the improved one.
Hierarchical basis methods for hypersingular integral equations

In this paper we present hierarchical basis methods for the Galerkin approximation of hypersingular integral equations on the interval Γ = (-1, 1). The condition number of the stiffness matrix with respect to the hierarchical basis is shown to behave like O (|log h| 2 ). The implementations are based on the preconditioned conjugate gradient method using a hierarchical basis (HB) preconditioner. The numerical results are presented with a comparison between the HB preconditioner and the BPX (Bramble, Pasciak and Xu) preconditioner.
Central European Journal of Mathematics Ring elements as sums of units

In an Artinian ring R every element of R can be expressed as the sum of two units if and only if R/J(R) does not contain a summand isomorphic to the field with two elements. This result is used to describe those finite rings R for which Γ(R) contains a Hamiltonian cycle where Γ(R) is the (simple) graph defined on the elements of R with an edge between vertices r and s if and only if r − s is invertible. It is also shown that for an Artinian ring R the number of connected components of the graph Γ(R) is a power of 2. MSC: 16P20, 16U60, 05C45
Higher‐order asymptotics in finance

A primary motivation of higher‐order asymptotic statistical analysis is to improve the first‐order limiting result in accordance with the celebrated Central Limit Theorem in the sense that a better approximation with higher order accuracy can be attained. In this article, several important tools in asymptotic analysis for obtaining higher‐order approximations, including Edgeworth expansions, saddle‐point approximations and Laplace integral method, will be revisited together with an introduction of some of their applications in finance. A new result on bounds for the difference between American and European calls on small dividend paying stock is also provided. WIREs Comput Stat 2012, 4:571–587. doi: 10.1002/wics.1234
A finiteness problem for one dimensional maps

On etudie le lien entre la densite d'applications structurellement stables dans l'espace des applications unimodales de l'intervalle, la finitude des attracteurs et la non-existence d'intervalles d'errance. On montre que dans l'espace des applications unimodales ayant un point critique plat eventuellement periodique, il y a un sous ensemble residuel dont les applications ont une infinite de trappes. Dans cet espace il y a aussi des applications ayant un intervalle d'errance
Image Register Based on PSO and Error Mechanism

When applying the standard particle swarm algorithm to image registering, it has a problem of convergence and the speed of the convergence. Aiming at this, we proposed a modified particle swarm optimization; a simple error correction mechanism is introduced into the update process of the particle, so that the particle’s error evolution can be corrected in time. To test the novel algorithm, we used a typical function to identify it. It can be seen from the simulation results that the convergence ability and the convergence speed of the new algorithm was increased effectively. Then applying the PSO algorithm to image registering, the experiment result is good.
Influences of Ru-doping on the magnetic properties of Ca0.85Pr0.15Mn1−xRuxO3

CaMnO3 is an antiferromagnet, in which the super-exchange interaction taking place between Mn4+ ions plays an important role. The doping of a small amount of 15% Pr into the Ca site, Ca0.85Pr0. 15MnO3, leads to the appearance of Mn3+ ions, and introduces the ferromagnetic (FM) double-exchange interaction between Mn3+ and Mn4+ ions, which is dominant in a narrow temperature range of 90 ∼ 115 K. The FM interaction becomes strong for Ca0.85Pr0. 15MnO3 doped with 4 and 8% Ru into the Mn site (i.e., Ca0.85Pr0.15Mn1−xRuxO3 with x = 0.04 and 0.08). The Curie temperature obtained for x = 0.04 and 0.08 are about 135 and 180 K, respectively. While the FM interaction in the former is dominant due to Mn3+-Mn4+ exchange pairs, the latter has the contribution of Ru ions. This results in remarkable differences in the features of their FM-paramagnetic phase transitions and their coercive fields Hc.
Crystal structure and magnetoresistance of Na-doped LaMnO3

The crystal structure and magnetoresistance of are investigated. La1-xNaxMnO3 crystallizes in a rhombohedrally distorted perovskite structure and exhibits a sharp ferromagnetic transition as well as a negative magnetoresistance at around room temperature. On the basis of alternating-current susceptibility and resistivity measurements as well as a comparison with La1-xNaxMnO3 compounds, it is proposed that Na doping tends to drive the system from a regime characterized by strong Hund coupling and strong electron-phonon coupling to one characterized by weak Hund coupling and weak electron-phonon coupling.
Theory of Scalar Wave Scattering by a Sphere and a Planar Substrate

The problem of scalar wave scattering by a sphere on or near a planar substrate is analytically solved. The solution is a set of wave functions coming in the form of infinite series of spherical and plane waves. In air, the incident plane wave is either scattered by the sphere or reflected from the substrate. A part of these scattered or reflected waves propagate to the other object where it is reflected and scattered again. Such processes of scattering and reflection repeat in turn indefinitely to generate multiply scattered waves, which are represented in the corresponding terms in the infinite series. The term in the series can be arranged in a recognizable manner to explicitly reveal the involved process and the multiplicity of scattering.
Numerical Fluid Dynamics.

By 1755, Euler was explicitly envisaging analytical fluid dynamics as a mathematical science, that of integrating the Euler–Lagrange equations. But by 1915, at least seven different analytical models were being used to explain the behavior of real fluids. From 1945 on, von Neumann was trying to “arithmetize” the approximate solution of the equations associated with these models, with the help of large-scale, high-speed computers. Thus he was envisaging numerical fluid dynamics as a mathematical science.After briefly reviewing the gradual disintegration of Euler’s concept of analytical fluid dynamics as a mathematical science, this survey article tries to assess the present status and future prospects of numerical fluid dynamics, through a series of case studies.
Bandwidth Choice for Average Derivative Estimation

Abstract The average derivative is the expected value of the derivative of a regression function. Kernel methods have been proposed as a means of estimating this quantity. The problem of bandwidth selection for these kernel estimators is addressed here. Asymptotic representations are found for the variance and squared bias. These are compared with each other to find an insightful representation for a bandwidth optimizing terms of lower order than n –1. It is interesting that, for dimensions greater than 1, negative kernels have to be used to prevent domination of bias terms in the asymptotic expression of the mean squared error. The extent to which the theoretical conclusions apply in practice is investigated in an economical example related to the so-called “law of demand. ”
Linear-response calculation of the effective coulomb interaction between closed-shell localized electrons: Cu, Zn, and ZnO

A linear-response method based on plane-wave basis density-functional theory to calculate the effective Coulomb interaction (U) between closed-shell localized electrons is suggested and applied to the 3d closed-shell systems (Cu, Zn, and ZnO). Since the closed-shell localized states are far below the Fermi level, a large local perturbation potential (α) projected to the localized states is applied to induce a purposeful density response (Δn). From the α, the perturbation potential cost for the density response onset, by which the Δn begins to be induced, is removed. The main screening channel for the effective Coulomb interaction is the itinerant electrons deoccupied from the perturbed localized states. The Cu, Zn, and ZnO 3d electron binding energies are calculated based on the local density approximation plus U, with the U values being calculated from the linear-response and being found to be in good agreement with the experimental values.
Ensemble Pruning for Data Dependant Learners

Ensemble pruning searches for a selective subset of members that performs as well as, or better than ensemble of all members. However, in the accuracy / diversity pruning framework, generalization ability of target ensemble is not considered, and moreover, there is not clear relationship between them. In this paper, we proof that ensemble formed by members of better generalization ability is also of better generalization ability. We adopt learning with both labeled and unlabeled data to improve generalization ability of member learners. A data dependant kernel determined by a set of unlabeled points is plugged in individual kernel learners to improve generalization ability, and ensemble pruning is launched as much previous work. The proposed method is suitable for both single-instance and multi-instance learning framework. Experimental results on 10 UCI data sets for single-instance learning and 4 data sets for multi-instance learning show that subensemble formed by the proposed method is effective.
Energetic stability, electronic structure, and magnetism in Mn-doped silicon dilute magnetic semiconductors

First-principles study on the energetic stability, electronic structure, and magnetic coupling in Mn-doped silicon with various configurations has been performed systematically. The results show that the poly-Mn atoms prefer to aggregate in the Mn-doped silicon dilute magnetic semiconductor. It is found that the tetrahedral interstitial Mn $({\text{Mn}}_{T})$ atoms assemble together via an intervening substitutional Mn $({\text{Mn}}_{\text{Si}})$ ion, subsequently forming the generally favored ${\text{Mn}}_{T}{\text{-Mn}}_{\text{Si}}{\text{-Mn}}_{T}$-type complexes. The dominant $d\text{\ensuremath{-}}d$ exchange interactions between the ${\text{Mn}}_{\text{Si}}$ and ${\text{Mn}}_{T}$ make all Mn ions in the ${\text{Mn}}_{T}{\text{-Mn}}_{\text{Si}}{\text{-Mn}}_{T}$ structures interact ferromagnetically with each other.
Determination of current-crowding effects on loss of light-output power in InGaN/GaN blue-light-emitting diodes

We analyzed the current-crowding process and its effects on carrier spill-over and light outputpower loss in InGaN/GaN blue-light-emitting diodes. When the current density was measured to be 3.1 times larger, the carrier spill-over was observed to be 1.9 times higher. The effects of current crowding on the loss of efficiency and on carrier spill-over were determined quantitatively. Through this analysis, we were able to correlate the degree of current crowding with the loss rate of lightoutput power. When the injected current was increased 2.5 times, the current-spreading length decreased 1.2 times, and the loss rate of the light-output power increased from 5% to 12%.
Generalized Schottky anomaly

The Schottky anomaly in the specific heat is one of the most universal phenomena in nature. The generalized Schottky anomaly for the combined system of two Hamiltonians \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathcal{H}_1 = - \mu B\sum\nolimits_i {\sigma _i }$$\end{document} (B: magnetic field) and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathcal{H}_2 = - J\sum\nolimits_{\left\langle {i,j} \right\rangle } {\sigma _i \sigma _j }$$\end{document} (J: coupling constant), both showing the Schottky anomaly, is systematically investigated for the first time. For a small magnetic field, we find the new fact that the maximum of the Schottky anomaly increases sharply and the Schottky temperature falls and then rises (making a sharp v shape) as the magnetic field B is increased. For a large magnetic field, as B increases, the maximum of the Schottky anomaly decreases, and the Schottky temperature increases gradually, in agreement with recent experimental measurements.
I Zw 1: Decomposition of the nearby QSO host

The paper presents an analysis of the nearby QSO host I Zw 1 based on new J-band imaging data, obtained with ISAAC at the Very Large Telescope (VLT) of the European Southern Observatory (ESO). As one of the best-studied QSOs with exceptional properties lying between those of QSOs, narrow-line Seyfert 1s, and ultraluminous infrared galaxies , I Zw 1 is a prime candidate for a detailed case study of a QSO host. With its high angular resolution and sensitivity, the new J-ba nd image provides strong evidence for an interaction between I Zw 1 and the western companion galaxy. We present a procedure for subtracting the QSO nucleus from the I Zw 1 image to obtain an undisturbed view on the underlying host galaxy. Based on the derived surface brightness profile and the gas rotatio n curve, the host is classified as a high-surface-brightness Freeman type I galaxy with a central disk surface brightness signific antly larger than that of normal spirals. The surface-brigh tness profile is decomposed into a Plummer bulge and a Kuzmin disk wi th similar luminosities and a bulge-to-disk scale length ra tio of 0.29, comparable to that of nearby spiral hosts with active galactic nuclei (AGN). Different models for the decomposition of the gas rotation curve are discussed. The resulting J-band mass-to-light ratio (M/L) of (0.7± 0.4) M⊙/L⊙ for the disk component suggests a mean solar-type stellar population with a tendency towards young stars. The bulge exhibits a lower M/L of (0.4± 0.2) M⊙/L⊙, which supports previous findings of enhanced starburst act ivity in the nuclear and circumnuclear region.
Additivity of Different Types of Masking

Two experiments were carried out to determine how masking for frequencies either above or below one band of noise combine with the critical‐band type masking produced by a second band of noise. The results of both experiments indicate that at moderately high levels the combination of critical‐band masking with another type of masking results in a 6‐db increase in masking. The implications of this result are discussed.