Miracle-dz/UniFAR-FTUs huggingface dataset:
Elastic scattering of electrons and positrons by atomic hydrogen and helium at intermediate and high energies

The eikonal Born series (EBS) method is used to analyse the elastic scattering of fast electrons and positrons by atomic hydrogen and helium. The properties of the terms of the Born and Glauber series are discussed, and in particular the dependence of these terms as a function of the (large) incident wavenumber k and the magnitude Delta of the momentum transfer. A more precise EBS treatment of small-angle scattering is presented by improving the calculation of the second Born term in this angular region. The EBS results agree very well with the recent absolute measurements of elastic differential cross sections, both for electron-atomic-hydrogen and electron-helium collisions.
Automatic classification of musical instrument sounds

The aim of the present study is to show that the process of automatic classification of musical instrument sounds is possible on the basis of a limited number of parameters. However, due to the complexity as well as to the unrepeatable nature of musical sounds, both steady and transient states should be taken into account while creating feature vectors. For this purpose a database of musical instrument sounds was built containing various instrument sounds played with a different articulation. Then, this database was used in further experiments consisting of some stages, i.e., preprocessing, parametrization, and pattern recognition. The main subject of this study was the optimization of the set of parameters to be included in the feature vectors. Therefore, the quality of parameters with regard to automatic pattern recognition was analyzed both using statistical methods and learning algorithms.
Coloron excitations of the SU(3) Haldane-Shastry model

In a recent publication, we proposed two possible wave functions for the elementary excitations of the SU(3) Haldane--Shastry model (HSM), but argued on very general grounds that only one or the other can be a valid excitation. Here we provide the explicit details of our calculation proving that the wave function describing a coloron excitation which transforms according to representation $\bar{3}$ under SU(3) rotations if the spins of the original model transform according to representation 3, is exact. We further provide an explicit construction of the exact color-polarized two-coloron eigenstates, and thereby show that colorons are free but that their relative momentum spacings are shifted according to fractional statistics with parameter $g=2/3$. We evaluate the SU(3) spin currents. Finally, we interpret our results within the framework of the asymptotic Bethe Ansatz and generalize some of them to the case of SU($n$).
High resolution study of domain nucleation and growth during polarization switching in Pb(Zr,Ti)O3 ferroelectric thin film capacitors

The domain nucleation and growth during polarization switching in Pb(Zr,Ti)O3 (PZT) ferroelectric thin film capacitors with Pt top (TE) and bottom electrodes (BE) were studied by means of atomic force microscopy (AFM). The experimental configuration used in this study differs from that conventionally used (AFM tip/PZT/BE) where the AFM tip acts as a positionable TE. A small ac voltage was applied between the electrodes with a step by step increasing dc bias voltage. The induced piezoelectric vibration was detected by the AFM tip, its amplitude and phase determined with the lock-in amplifier. The phase difference between the applied ac voltage and the piezoelectric signal as a function of the x-y position was nearly locked at 0 or 180, representing film regions with parallel (in-phase) and antiparallel (antiphase) polarization direction, respectively. The polarization reversal was induced by application of a step by step increasing dc bias field opposite to the polarization of the prepoled sample. At each .
A transformation model for two survival curves: An empirical process approach

SUMMARY A new transformation model for two survival curves with possibly nonproportional hazards is presented. The model assumes the existence of an unknown transformation of the survival curves into Weibull distributions with different shape parameters. The partial likelihood approach fails in the model. A new method of estimation called the empirical process approach is proposed. This approach is based on the strong approximation of the Kaplan-Meier product-limit estimators and associated quantile functions. Asymptotic normality of the generalised least squares estimator derived from the approach is discussed. A readily defined Wald test is an alternative to the log-rank test. From the empirical process approach, a Pearson's x2 goodness-of-fit test of the transformation model assumption can also be derived, giving a new test for the proportionality of hazard functions. The model can be applied for K-sample problems as well.
Complexity Analysis of a Sampling-Based Interior Point Method for Convex Optimization

We develop a short-step interior point method to optimize a linear function over a convex body assuming that one only knows a membership oracle for this body. The approach is based a sketch of a universal interior point method using the so-called entropic barrier. It is well known that the gradient and Hessian of the entropic barrier can be approximated by sampling from Boltzmann-Gibbs distributions and the entropic barrier was shown to be self-concordant. The analysis of our algorithm uses properties of the entropic barrier, mixing times for hit-and-run random walks, approximation quality guarantees for the mean and covariance of a log-concave distribution, and results on inexact Newton-type methods.
Research Progress on The Seismic Performance of Fabricated Concrete Structures

In recent decades, the application of prefabricated structures has become more and more extensive, especially for prefabricated concrete structures. The research on its seismic performance plays a significant role in the process of application and promotion of this structure. This paper mainly summarizes the research results on the seismic performance of prefabricated concrete structures, and it is actually based on the seismic research of dry connections, wet connections, new connections and different structural systems. The new dry connections with good seismic performance are considered to have better application prospects. In addition, it analyses the application of seismic design with recoverable functions in this field, and it is concluded that new seismic technologies such as recoverable function structures and damage control structures should be widely used. Finally, the research status of seismic performance of prefabricated concrete structures is summarized and analyzed. In the future promotion and application, it is necessary to continuously update the relevant regulations and improve seismic design methods and technologies.
The Role of Energy Minimization in Algebraic Multigrid Interpolation

Algebraic multigrid (AMG) methods are powerful solvers with linear or near-linear computational complexity for certain classes of linear systems, Ax=b. Broadening the scope of problems that AMG can effectively solve requires the development of improved interpolation operators. Such development is often based on AMG convergence theory. However, convergence theory in AMG tends to have a disconnect with AMG in practice due to the practical constraints of (i) maintaining matrix sparsity in transfer and coarse-grid operators, and (ii) retaining linear complexity in the setup and solve phase. This paper presents a review of fundamental results in AMG convergence theory, followed by a discussion on how these results can be used to motivate interpolation operators in practice. A general weighted energy minimization functional is then proposed to form interpolation operators, and a novel `diagonal' preconditioner for Sylvester- or Lyapunov-type equations developed simultaneously. Although results based on the weighted energy minimization typically underperform compared to a fully constrained energy minimization, numerical results provide new insight into the role of energy minimization and constraint vectors in AMG interpolation.
Spectral Multipliers of Self-Adjoint Operators on Besov and Triebel–Lizorkin Spaces Associated to Operators

Let $X$ be a space of homogeneous type and let $L$ be a nonnegative self-adjoint operator on $L^2(X)$ that satisfies a Gaussian estimate on its heat kernel. In this paper we prove a Hörmander-type spectral multiplier theorem for $L$ on the Besov and Triebel–Lizorkin spaces associated to $L$. Our work not only recovers the boundedness of the spectral multipliers on $L^p$ spaces and Hardy spaces associated to $L$ but also is the 1st one that proves the boundedness of a general spectral multiplier theorem on Besov and Triebel–Lizorkin spaces.
Passivation of Pb0 and Pb1 interface defects in thermal (100) Si/SiO2 with molecular hydrogen

It is found that the passivation of both the Pb0 and Pb1 defects in (100)Si/SiO2 (grown at <750 °C) with molecular H2 may well be described by the same defect‐ H2 reaction‐limited kinetic model applying to interfacial Pb defects in (111) Si/SiO2 grown at 850 °C. Yet, whereas Pb was typified by a single‐valued activation energy Ea=1.66 eV, both Pb0 and Pb1 are found to exhibit a Gaussian spread σEa=0.15±0.03 eV around their respective mean Ea values, determined as 1.51 and 1.57±0.04 eV. Such a spread complies with previous electron spin resonance data on stress‐induced structural variations within the Pb bath. All three interface defects thus passivate comparably.
Classical solutions in three-dimensional Einstein-Maxwell cosmological gravity

The three-dimensional cosmological Einstein-Maxwell equations for fields depending on only one variable are shown to have a hidden SO(2,1) group of invariance. The solution of the coupled field equations is reduced to that of the special relativistic motion of a particle in a given potential. A wide class of exact stationary rotationally symmetric solutions are derived and discussed.
A Sharp Convergence Rate Analysis for Distributed Accelerated Gradient Methods

In this paper, we study the computation and communication costs in decentralized distributed optimization and give a sharp complexity analysis for the proposed distributed accelerated gradient methods. We present two algorithms based on the framework of the accelerated penalty method with increasing penalty parameters. Our first algorithm achieves the $O\left(\left(\epsilon\sqrt{1-\sigma_2(W)}\right)^{-1}\right)$ complexities for both computation and communication, which match the communication complexity lower bound for non-smooth distributed optimization, where $\sigma_2(W)$ denotes the second largest singular value of the weight matrix $W$ associated to the network. Our second algorithm employs a double-loop and obtains the near optimal $O\left(\sqrt{L/\left(\epsilon(1-\sigma_2(W))\right)}\log\epsilon^{-1}\right)$ communication complexity and the optimal $O\left(\sqrt{L/\epsilon}\right)$ computation complexity for $L$-smooth distributed optimization. When the problem is $\mu$-strongly convex and $L$-smooth, our second algorithm has the near optimal $O\left(\sqrt{L/\left(\mu(1-\sigma_2(W))\right)}\log^2\epsilon^{-1}\right)$ complexity for communication and the optimal $O\left(\sqrt{L/\mu}\log\epsilon^{-1}\right)$ computation complexity. Our communication complexities are only worse by a factor of $\log\epsilon^{-1}$ than the lower bounds for the smooth distributed optimization.
Helium runaways in white dwarfs

The long-term evolution of a carbon-accreting white dwarf (M=0.5 M/sub sun/) has been studied from the onset of accretion to the ignition of helium. The variations in the details of the helium-shell flash have been examined with respect to variations in mass accretion rate. For intermediate rates (10/sup -9/-10/sup -8/ M/sub sun/ yr/sup -1/) the helium flash is potentially explosive, whereas for high rates (5 x 10/sup -8/ M/sub sun/ yr/sup -1/) the shell flash is relatively weak. The results are discussed in the context of the long-term evolution of novae.
Grandparent-grandchild Relationships and the Psychological and Health Outcomes of Early Adult Grandchildren: An Integrative Review

ABSTRACT The aim of the current integrative review was to achieve a better understanding of the associations between the grandparent-grandchild relationship and early adult grandchildren’s psychological and health outcomes. The current article examines the grandparent’s role in view of different aspects of the grandparent-grandchild relationship by analyzing two themes that emerged in the reviewed studies: the general grandparent-grandchild relationship and the relationship with a grandparent with an impairment. Gaps in the research literature, implications for practice and directions for future research are discussed.
Accuracy of computation of crystalline defects at finite temperature

The present paper aims at developing a theory of computation of crystalline defects at finite temperature. In a one-dimensional setting we introduce Gibbs distributions corresponding to such defects and rigorously establish their asymptotic expansion. We then give an example of using such asymptotic expansion to compare the accuracy of computations using the free boundary conditions and using an atomistic-to-continuum coupling method.
Low-Profile SIW-Based Triplex Filtering Antenna With Improved Gain

In this brief, a low-profile triple-fed high-isolation triplex filtering antenna is proposed based on the substrate integrated waveguide (SIW), for the first time. By co-sharing radiators, constructing common feeding resonant cavities and loading additional metal via holes, a closely-spaced-channel triplexer topology is developed with three adjustable frequency passbands. To verify the proposed concept, a prototype operating at 6.68 GHz, 7.52 GHz and 8.0 GHz is designed, simulated and measured. It exhibits high channel-to-channel isolation of over 21.83 dB as well as good passband gains of 7.1 dBi, 4.55 dBi and 5.99 dBi, respectively.
Approximating the Laplace transform of the sum of dependent lognormals

Abstract Let (X 1,.,X n ) be multivariate normal, with mean vector 𝛍 and covariance matrix 𝚺, and let S n =e X 1 +⋯+e X n . The Laplace transform ℒ(θ)=𝔼e-θS n ∝∫exp{-h θ(𝒙)}d𝒙 is represented as ℒ̃(θ)I(θ), where ℒ̃(θ) is given in closed form and I(θ) is the error factor (≈1). We obtain ℒ̃(θ) by replacing h θ(𝒙) with a second-order Taylor expansion around its minimiser 𝒙*. An algorithm for calculating the asymptotic expansion of 𝒙* is presented, and it is shown that I(θ)→ 1 as θ→∞. A variety of numerical methods for evaluating I(θ) is discussed, including Monte Carlo with importance sampling and quasi-Monte Carlo. Numerical examples (including Laplace-transform inversion for the density of S n ) are also given.
Tail mutual exclusivity and Tail-VaR lower bounds

In this paper, we extend the concept of mutual exclusivity proposed by [Dhaene, J. & Denuit, M. (1999). The safest dependence structure among risks. Insurance: Mathematics and Economics 25, 11–21] to its tail counterpart and baptize this new dependency structure as tail mutual exclusivity. Probability levels are first specified for each component of the random vector. Under this dependency structure, at most one exceedance over the corresponding Value-at-Risks (VaRs) is possible, the other components being zero in such a case. No condition is imposed when all components stay below the VaRs. Several properties of this new negative dependence concept are derived. We show that this dependence structure gives rise to the smallest value of Tail-VaR (TVaR) of a sum of risks within a given Fréchet space, provided that the probability level of the TVaR is close enough to one.
Low‐complexity robust adaptive generalized sidelobe canceller detector for DS/CDMA systems

A novel low computational complexity robust adaptive blind multiuser detector, based on the minimum output energy (MOE) detector with multiple constraints and a quadratic inequality (QI) constraint is developed in this paper. Quadratic constraint has been a widespread approach to improve robustness against mismatch errors, uncertainties in estimating the data covariance matrix, and random perturbations in detector parameters. A diagonal loading technique is compulsory to achieve the quadratic constraint where the diagonal loading level is adjusted to satisfy the constrained value. Integrating the quadratic constraint into recursive algorithms seems to be a moot point since there is no closed‐form solution for the diagonal loading term. In this paper, the MOE detector of DS/CDMA system is implemented using a fast recursive steepest descent adaptive algorithm anchored in the generalized sidelobe canceller (GSC) structure with multiple constraints and a QI constraint on the adaptive portion of the GSC structure. The Lagrange multiplier method is exploited to solve the QI constraint. An optimal variable loading technique, which is capable of providing robustness against uncertainties and mismatch errors with low computational complexity is adopted. Simulations for several mismatch and random perturbations scenarios are conducted in a rich multipath environment with near–far effect to explore the robustness of the proposed detector. Copyright © 2008 John Wiley & Sons, Ltd.
Actions of measured quantum groupoids on a finite basis

In this article, we generalize to the case of measured quantum groupoids on a finite basis some important results concerning actions of locally compact quantum groups on C*-algebras [S. Baaj, G. Skandalis and S. Vaes, 2003]. Let $\cal G$ be a measured quantum groupoid on a finite basis. We prove that if $\cal G$ is regular, then any weakly continuous action of $\cal G$ on a C*-algebra is necessarily strongly continuous. Following [S. Baaj and G. Skandalis, 1989], we introduce and investigate a notion of $\cal G$-equivariant Hilbert C$^*$-modules. By applying the previous results and a version of the Takesaki-Takai duality theorem obtained in [S. Baaj and J. C. , 2015] for actions of $\cal G$, we obtain a canonical equivariant Morita equivalence between a given $\cal G$-C$^*$-algebra $A$ and the double crossed product $(A\rtimes{\cal G})\rtimes\widehat{\cal G}$.
Finding Edges and Lines in Images

Abstract : The problem of detecting intensity changes in images is canonical in vision. Edge detection operators are typically designed to optimally estimate first or second derivative over some (usually small) support. Other criteria such as output signal to noise ratio or bandwidth have also been been argued for. This thesis is an attempt to formulate a set of edge detection criteria that capture as directly as possible the desirable properties of an edge operator. Variational techniques are used to find a solution over the space of all linear shift invariant operators. The first criterion is that the detector have low probability of error i.e. failing to mark edges or falsely marking non-edges. The second is that the marked points should b The third criterion is that there should be low probability of more than one response to a single edge. The technique is used to find optimal operators for step edges and for extended impulse profiles (ridges or valleys in two dimensions). The extension of the one dimensional operators to two dimensions is then discussed. The result is a set of operators of varying width, length and orientation. The problem of combining these outputs into a single description is discussed, and a set of heuristics for the integration are given. (Author)
Polarmetric classification of scattering centers

Polarimetric diversity can be exploited in synthetic aperture radar (SAR) for enhanced target detection and target description. Detection statistics and target features can be computed from either polarimetric imagery or parametric processing of SAR phase histories. We adopt an M- ary Bayes classification approach and derive Bayes-optimal decision rules for detection and description of scattering centers. Scattering centers are modeled as one of M canonical geometric types with unknown amplitude, phase and orientation angle; clutter is modeled as one of M canonical geometric types with unknown amplitude, phase and orientation angel; clutter is modeled as a spherically invariant random vector. For the Bayes optimal decision rules, we provide a simple geometric interpretation and an efficient computational implementation. Moreover, we characterize the certainty of decisions by deriving an approximate posteriori probability.
The density of eigenvalues seen from the soft edge of random matrices in the Gaussian beta-ensembles

We characterize the phenomenon of "crowding" near the largest eigenvalue $\lambda_{\max}$ of random $N \times N$ matrices belonging to the Gaussian $\beta$-ensemble of random matrix theory, including in particular the Gaussian orthogonal ($\beta=1$), unitary ($\beta=2$) and symplectic ($\beta = 4$) ensembles. We focus on two distinct quantities: (i) the density of states (DOS) near $\lambda_{\max}$, $\rho_{\rm DOS}(r,N)$, which is the average density of eigenvalues located at a distance $r$ from $\lambda_{\max}$ (or the density of eigenvalues seen from $\lambda_{\max}$) and (ii) the probability density function of the gap between the first two largest eigenvalues, $p_{\rm GAP}(r,N)$. Using heuristic arguments as well as well numerical simulations, we generalize our recent exact analytical study of the Hermitian case (corresponding to $\beta = 2$). We also discuss some applications of these two quantities to statistical physics models.
On sunlet graphs connected to a specific map on {1, 2, . . . , p − 1}

In this article, we study the structure of the graph implied by a given map on the set $S_p=\{1,2,\dots,p-1\}$, where $p$ is an odd prime. The consecutive applications of the map generate an integer sequence, or in graph theoretical context a walk, that is linked to the discrete logarithm problem.
Conservation Properties of the Trapezoidal Rule in Linear Time Domain Analysis of Acoustics and Structures

The trapezoidal rule, which is a special case of the Newmark family of algorithms, is one of the most widely used methods for transient hyperbolic problems. In this work, we show that this rule conserves linear and angular momenta and energy in the case of undamped linear elastodynamics problems, and an ``energy-like measure'' in the case of undamped acoustic problems. These conservation properties, thus, provide a rational basis for using this algorithm. In linear elastodynamics problems, variants of the trapezoidal rule that incorporate ``high-frequency'' dissipation are often used, since the higher frequencies, which are not approximated properly by the standard displacement-based approach, often result in unphysical behavior. Instead of modifying the trapezoidal algorithm, we propose using a hybrid finite element framework for constructing the stiffness matrix. Hybrid finite elements, which are based on a two-field variational formulation involving displacement and stresses, are known to approximate the eigenvalues much more accurately than the standard displacement-based approach, thereby either bypassing or reducing the need for high-frequency dissipation. We show this by means of several examples, where we compare the numerical solutions obtained using the displacement-based and hybrid approaches against analytical solutions.
Generalized Nonlinear Complementary Attitude Filter

A = matrices a = true value ~ A = Â T A ; left multiply error â = estimated value a = measured value ~ a = error between estimated and true values hai = time-averaged expectation value A;B , fA;Bg = commutator or anticommutator of A and B A = equilibrium point AI = CAC ; matrix in inertial frame Ps A , Pa A = symmetric or antisymmetric projection of A x = vectors x = matrix equivalent form of cross product xI = Cx; vector in inertial frame