Miracle-dz/UniFAR-FTUs huggingface dataset:
A necessary and sufficient condition for global convergence of the zeros of random polynomials.

Consider random polynomials of the form $G_n = \sum_{i=0}^n \xi_i p_i$, where the $\xi_i$ are i.i. d. non-degenerate complex random variables, and $\{p_i\}$ is a sequence of orthonormal polynomials with respect to a regular measure $\tau$ supported on a compact set $K$. We show that the normalized counting measure of the zeros of $G_n$ converges weakly almost surely to the equilibrium measure of $K$ if and only if $\mathbb E \log(1 + |\xi_0|) e^n) = o(n^{-1})$. Our proofs rely on results from small ball probability and exploit the structure of general orthogonal polynomials. Our methods also work for sequences of asymptotically minimal polynomials in $L^p(\tau)$, where $p \in (0, \infty]$. In particular, sequences of $L^p$-minimal polynomials and (normalized) Faber and Fekete polynomials fall into this class.
Microwave absorption performance of reduced graphene oxide with negative imaginary permeability

In this work, reduced graphene oxide (RGO) aerogels of various pore sizes were fabricated by hydrothermal and lyophilizing processes and their influence on microwave absorption via optimization of electrical conductivity and permittivity was studied. At a fixed aerogel filler loading of 1.7 wt. %, both the electrical conductivity and permittivity of the RGO/wax composites were first increased and then decreased by increasing the pore size in the RGO aerogels. Impressively, when electrical conductivity is sufficiently high, the negative imaginary part of the permeability () can be observed at the same time. This work provides an effective method of fabricating highly efficient electromagnetic wave absorbents while optimizing dielectric loss and impedance matching behaviors, as well as direct evidence on the understanding of the negative phenomenon.
On the connections of sub-Finslerian geometry

A sub-Finslerian manifold is, roughly speaking, a manifold endowed with a Finsler type metric which is defined on a [Formula: see text]-dimensional smooth distribution only, not on the whole tangent manifold. Our purpose is to construct a generalized nonlinear connection for a sub-Finslerian manifold, called [Formula: see text]-connection by the Legendre transformation which characterizes normal extremals of a sub-Finsler structure as geodesics of this connection. We also wish to investigate some of its properties like normal, adapted, partial and metrical.
Nonparametric survival function estimation for data subject to interval censoring case 2

ABSTRACT In this paper, we propose a new strategy of estimation for the survival function S, associated to a survival time subject to interval censoring case 2. Our method is based on a least squares contrast of regression type with parameters corresponding to the coefficients of the development of S on an orthonormal basis. We obtain a collection of projection estimators where the dimension of the projection space has to be adequately chosen via a model selection procedure. For compactly supported bases, we obtain adaptive results leading to general nonparametric rates. However, our results can be used for non-compactly supported bases, a true novelty in regression setting, and we use specifically the Laguerre basis which is -supported and thus well suited when non-negative random variables are involved in the model. Simulation results comparing our proposal with previous strategies show that it works well in a very general context. A real dataset is considered to illustrate the methodology.
Outflowing gas in a compact ionization cone in the Seyfert 2 galaxy ESO 153-G20

We present two-dimensional ionized gas and stellar kinematics in the inner 1.4 × 1.9 kpc2 of the Seyfert 2 galaxy ESO 153-G20 obtained with the Gemini-South/Gemini multi-object spectrograph integral field unit (GMOS-IFU) at a spatial resolution of ~250 pc and spectral resolution of 36 km s−1. Strong [O iii], Hα, [N ii] and [S ii] emission lines are detected over the entire field of view. The stellar kinematics trace circular rotation with a projected velocity amplitude of ±96 km s−1, a kinematic major axis in position angle of 11°, and an average velocity dispersion of 123 km s−1. To analyse the gas kinematics, we used aperture spectra, position–velocity diagrams and single/double Gaussian fits to the emission lines. All lines show two clear kinematic components: a rotating component that follows the stellar kinematics, and a larger-dispersion component, close to the systemic velocity (from which most of the [O iii] emission comes), mainly detected to the south-west. We interpret this second component as gas outflowing at ∼400 km s−1 in a compact (300 pc) ionization cone with a half-opening angle ≤40°. The counter-cone is probably obscured behind a dust lane. We estimate a mass outflow rate of 1.1 M$\odot$ yr−1, 200 times larger than the estimated accretion rate on to the supermassive black hole, and a kinetic to radiative power ratio of 1.7 × 10−3. Bar-induced perturbations probably explain the remaining disturbances observed in the velocity field of the rotating gas component.
(ω,c)‐asymptotically periodic functions, first‐order Cauchy problem, and Lasota‐Wazewska model with unbounded oscillating production of red cells

In this paper, we study a new class of functions, which we call (ω,c)‐asymptotically periodic functions. This collection includes asymptotically periodic, asymptotically antiperiodic, asymptotically Bloch‐periodic, and unbounded functions. We prove that the set conformed by these functions is a Banach space with a suitable norm. Furthermore, we show several properties of this class of functions as the convolution invariance. We present some examples and a composition result. As an application, we prove the existence and uniqueness of (ω,c)‐asymptotically periodic mild solutions to the first‐order abstract Cauchy problem on the real line. Also, we establish some sufficient conditions for the existence of positive (ω,c)‐asymptotically periodic solutions to the Lasota‐Wazewska equation with unbounded oscillating production of red cells.
Remote Sensing Scene Classification by Gated Bidirectional Network

Remote sensing (RS) scene classification is a challenging task due to various land covers contained in RS scenes. Recent RS classification methods demonstrate that aggregating the multilayer convolutional features, which are extracted from different hierarchical layers of a convolutional neural network, can effectively improve classification accuracy. However, these methods treat the multilayer convolutional features as equally important and ignore the hierarchical structure of multilayer convolutional features. Multilayer convolutional features not only provide complementary information for classification but also bring some interference information (e.g., redundancy and mutual exclusion). In this paper, a gated bidirectional network is proposed to integrate the hierarchical feature aggregation and the interference information elimination into an end-to-end network. First, the performance of each convolutional feature is quantitatively analyzed and a superior combination of convolutional features is selected. Then, a bidirectional connection is proposed to hierarchically aggregate multilayer convolutional features. Both the top–down direction and the bottom–up direction are considered to aggregate multilayer convolutional features into the semantic-assist feature and appearance-assist feature, respectively, and a gated function is utilized to eliminate interference information in the bidirectional connection. Finally, the semantic-assist feature and appearance-assist feature are merged for classification. The proposed method can compete with the state-of-the-art methods on four RS scene classification data sets (AID, UC-Merced, WHU-RS19, and OPTIMAL-31).
A closed-form quasi-maximum likelihood estimator of bid-ask spread

Abstract We propose a closed-form quasi-maiximum likelihood (QML) estimator of bid-ask spread from daily high-low ranges under both near-ideal and overnight theoretical frameworks. As is shown that the high-low spread estimator is more precise than that only using closing prices, we pay attention to investigating the statistical properties of such kind of range-based spread estimators, and further demonstrating that our estimator is free from overnight adjustment with higher estimation efficiency. Simulation studies show that the QML estimator has relatively lower bias and RMSE, compared with other prevalent low-frequency measures, and the results are more significant under overnight conditions.
Patrones de fermentación y estabilidad aeróbica de ensilaje de sorgo forrajero (Sorghum bicolor M) con diferentes niveles de inclusión de pulpa integral de jícaro ( Crescentia al ata)

Se evaluo la calidad nutritiva, patrones de fermentacion y la estabilidad aerobica de ensilaje de sorgo forrajero (Sorghum Bicolor m.) con diferentes niveles de inclusion de pulpa de jicaro integral ( Crescentia a/ata), en 11 tratamientos con 5 repeticiones, con distintas proporciones de pulpa de jicaro y de sorgo mas melaza al 5%, mediante un diseno completamente al azar (DCA), con micro silos con capacidad de 4 kg, ± 0.7, abiertos a los 230 dias, se valoro Materia Seca, Proteina Bruta, Potencial de Hidrogeno, Nitrogeno Amoniacal y Dias al Deterioro Aerobico; el Analisis de Varianza y comparaciones de medias con la Prueba de Tukey al 95% encontro diferencias significativas entre tratamientos, los tratamientos Tl, T9 y TlO obtuvieron los mejores resultados en cuanto a proteina Bruta, Materia Seca, Potencial de hidrogeno, Nitrogeno amoniacal y dias al deterioro aerobico lo que garantizan un ensilaje de calidad, comprobandose que la pulpa integral de Jicaro tiene un efecto positivo sobre la composicion quimica, la fermentacion y la estabilidad aerobica del ensilaje. La pulpa de Jicaro integral es una alternativa viable y sostenible para la alimentacion animal ya que es un recurso existente en la zona seca de Nicaragua que puede dar respuesta a la problematica de alimentacion en verano.
Structure of the hydrogen fluoride liquid/vapour interface investigated using molecular dynamics simulations

Fluorwasserstoff ist eine der einfachsten molekularen Flussigkeiten, die sich jedoch durch seine lineare Geometrie und seinen ausgepragten dipolaren Charakter auszeichnet. Trotz der einfachen Molekulstruktur unterscheiden sich die Eigenschaften der flussigen Phase deutlich von anderen molekularen Flussigkeiten. Fehlendes Verstandnis dieser Besonderheit liegt besonders in der Limitation der experimentellen Untersuchung von Fluorwasserstoff begrundet. In dieser Arbeit wird, unter Verwendung von Molekular-Dynamik Simulationen, die Grenzflache zwischen flussiger und gasformiger Phase von Fluorwasserstoff untersucht. Um die Simulation dieses Systems zu ermoglichen, wird ein bestehendes polarisierbares Model fur Fluorwasserstoffmittels eines klassischen Drude Oszillatorsmodifiziert. Die hier prasentierten Ergebnisse sind die erste mikroskopischen Studie der Grenzflache zwischen flussiger und gasformiger Phase bei Fluorwasserstoff. Das Modell reproduziert qualitativ die experimentell bestimmten thermodynamischen Eigenschaften bei flussig/gasformig-Koexistenz, wobei besonders die Steigung der Dampfdruckkurve und die niedrige Oberflachenspannung hervorzuheben sind. Die niedrige Oberflachenspannung von Fluorwasserstoff fuhrt zu einer stark zerfurchten Grenzflache und der Entstehung von Hohlraumen in der flussigen Phase. Trotz komplexer Morphologie und langwelliger Fluktuationen der Grenzflache kann mit Hilfe von Intrinsischer Analyse die Auspragung stark strukturierter, aufeinanderfolgender Schichten gezeigt werden. Untersuchung der Netzwerkstruktur des simulierten Systems offenbart die Existenz langer, linearer Ketten und stark verzweigter Cluster, die aufgrund der starken Polaritat desModells entstehen. Diese Strukturen konnen auch aus der Grenzregion herausragen und sich deutlich in die gasformige Region erstrecken, wodurch eine einzigartige flussig/gasformig-Morphologie entsteht, die mit keiner anderen molekularen Flussigkeit vergleichbar ist.
Disturbance observer-based fixed-time prescribed performance tracking control for robotic manipulator

ABSTRACT This paper investigates the fixed-time prescribed performance tracking control for the n-DOF uncertain manipulator. First, a novel Barrier Lyapunov Function (BLF) is proposed to guarantee the prescribed performance for the manipulator tracking error. Then, we introduce a disturbance observer to estimate the system uncertainty and disturbance accurately in a predefined time. Next, a composite controller based on the nonsingular fast integral terminal sliding mode is constructed. It is strictly proved that the closed-loop system is stable in fixed-time, which is independent of the initial conditions. Moreover, both transient and steady-state performances of the outputs can be preserved. Finally, numerical simulations and experimental studies are presented to demonstrate the effectiveness of the proposed methods.
Mantle transition zone structure around Hainan by receiver function analysis

We have obtained the upper mantle 410 km discontinuity and 660-km discontinuity structure and transition zone thickness around Hainan by using receiver function method.The data used in this study was teleseismic waveforms recorded by 88 seismic stations of Hainan,Guangdong and Guangxi Regional Seismic Network and National Seismic Network during August,2007 to March,2010.Our results show that the structure of 410 km discontinuity is complex in this region,it is depressed to 447 km locally.The 660 km discontinuity is simple relatively,with the depth around 670km.Transition zone is thinned anomalously by 25±5km within an area approximately 200km in diameter centered northeast of Hainan island,this anomaly is consistent with an excess temperature of ～180℃. The locally thinned transition zone implies that Hainan plume originates from lower mantle.
Influence of an uneven surface on the vibration occurrence affecting the tractor operator

The paper presents a study of the influence of an uneven surface and number of tractor hours on vibration that is transmitted to the operator's hand-arm system during operation. The study was conducted on the asphalt, gravel and grass traversal during 2015 and 2016. The results indicate that the movement of a tractor on different agrotechnical surfaces generates vibrations of varying intensity that affect the hand-arm system of the operator. The highest vibration values were recorded on the asphalt, while the least vibrations were measured on the grass. The measured maximum vibration values are lower than the permissible 5 m·s−2 in the direction of all three axes, making it possible to assume that they are not harmful to the health of the operator.
Influência da rigidez da parte anterior da entressola do tênis no deslocamento angular do pé e na potência de joelho durante a marcha

Introducao: A rigidez de compressao da parte anterior da entressola do tenis pode influenciar na cinematica e cinetica dos membros inferiores. E possivel que uma entressola com menor rigidez aumente o deslocamento angular dos segmentos do pe e aumente a potencia dos membros inferiores. Objetivo: Avaliar a influencia da rigidez da parte anterior da entressola do tenis no deslocamento angular dossegmentos do pe, joelho e quadril e na potencia de tornozelo, joelho e quadril durante a fase de apoio da marcha. Metodo: Dados cinematicos e cineticos tridimensionais do membro inferior de 37 sujeitos saudaveis utilizando dois niveis diferentes de rigidez da parte anterior da entressola do tenis (condicoes baixa-rigidez e alta-rigidez) foram obtidos durante a fase de apoio da marcha por meio da utilizacao do sistema Qualisys ProReflex sincronizado a uma plataforma de forca. As variaveis dependentes do estudo foram: deslocamento angular de antepe-tibia eretrope nos planos frontal e transverso e de joelho e quadril no plano transverso e potencia de tornozelo, joelho e quadril no plano sagital durante a fase de apoio da marcha. Os dados foram analisados inicialmente extraindo a amplitude total de movimento de antepe-tibia e retrope das curvas de deslocamento angular e pela aplicacao da analise de componentes principais para extrair as diferencas em formato e magnitude nas curvas de deslocamento angular e de potencia entre asduas condicoes. Resultados: A condicao baixa-rigidez apresentou maior amplitude de movimento total no plano transverso de antepe-tibia e retrope do que a condicao alta-rigidez (=0,05). A analise de componentes principais detectou diferencas estatisticamente significativas em formato e magnitude entre as curvas dedeslocamento angular e de potencias duas condicoes. Conclusoes: Os achados sugerem a influencia da rigidez de compressao da parte anterior da entressola sobre a cinematica dos segmentos do pe e sobre a geracao de potencia na articulacao do joelho durante a fase de apoio da marcha. A condicao baixa-rigidez foi associada a um atraso na geracao de energia durante a fase final de apoio o que pode influenciarnegativamente o desempenho do individuo durante a marcha.
New distribution function estimators and tests of perfect ranking in concomitant-based ranked set sampling

Abstract Ranked set sampling (RSS) allows us to draw inference about the population parameters more efficiently as compared with that in simple random sampling. Recent publication has shown that using the concomitant information can lead to improved estimation of the cumulative distribution function (CDF) under RSS set up. In this article, new estimators for both in-stratum and overall CDF are proposed. The proposed estimators are then used for estimating the differential entropy, Bohn and Wolfe model and fraction-of-random model. Three new simple tests for the assumption of perfect ranking are also produced. Our simulation results show that the suggested estimators as well as the perfectness tests provide higher efficiency against their competitors. For illustrative purposes, the proposed procedures are applied on empirical data set in the medical field.
Computation of Admissible Marking Sets in Weighted Synchronization-Free Petri Nets by Dynamic Programming

We study the computation of admissible marking sets in generalized Petri nets. We first show that the admissibility checking in the generalized Petri net is NP-hard. Then, we consider a special subclass of generalized Petri nets called weighted-synchronization-free nets in which each transition has at most one input place. For a net in this subclass, we propose a generating function to compute by dynamic programming the set of admissible markings for a given generalized mutual exclusion constraint.
Does January Effect Exist in Jordan Pre and Post the 2008 Global Financial Crisis

The aim of this paper lies in investigating the existence of the January effect at the Amman Stock Exchange (ASE) pre and post the 2008 global financial crisis. For this purpose, the monthly returns of all stock prices in (ASE) have been calculated and analyzed for the period January 2000-December, 2018. The said analysis covered three periods as follows: the first one is the whole period; the second period is from January 2000-December 2007, while the third period is from January 2009-December 2018. Regression models with dummy variables and monthly returns of all shares have been used. The results indicated that the January effect exists at (ASE) during the whole period and the period before the global crisis, while the January effect after the global crisis 2008 does not exist at (ASE). Conversely, the results showed the existence of the December effect. Therefore, there is an opportunity for investors at (ASE) to benefit from these findings.
Turbulent drag reduction in Taylor-Couette flows using different super-hydrophobic surface configurations

Turbulent drag reduction (DR) in an incompressible Taylor-Couette flow configuration using different patterns of “idealized” superhydrophobic surfaces (SHS) on rotating inner-wall is investigated using direct numerical simulations (DNS). Three dimensional DNS studies based on the finite difference method in cylindrical annuli of aspect ratio (Γ) = 6.0 and radius ratios (η) = 0.5 and 0.67 have been performed at Reynolds numbers (Re) 4000 and 5000. The SHS comprised of streamwise or azimuthal microgrooves (MG), spanwise or longitudinal MG, grooves inclined to the streamwise direction (spiral), and microposts. The SHS have been modeled as shearfree areas. We were able to achieve a maximum DR up to 34% for the streamwise aligned SHS, while we got drag enhancement of 4% for the spiral SHS at η = 0.67. The SHS cause slip at the wall as well as near-wall turbulence modification, both governing the DR. We have tried to understand the role of the effective slip and modified turbulence dynamics responsible for DR by analyzing the statistics of mean flow, velocity fluctuations, Reynolds stresses, turbulence kinetic energy (TKE), and near-wall streaks. Most of the results show enhanced production of near-wall streamwise velocity fluctuations and TKE resulting in near-wall turbulence enhancement, yet we observed DR for most of the cases, thereby implying slip to be the dominant contributor to DR in comparison to modified near-wall turbulence.Turbulent drag reduction (DR) in an incompressible Taylor-Couette flow configuration using different patterns of “idealized” superhydrophobic surfaces (SHS) on rotating inner-wall is investigated using direct numerical simulations (DNS). Three dimensional DNS studies based on the finite difference method in cylindrical annuli of aspect ratio (Γ) = 6.0 and radius ratios (η) = 0.5 and 0.67 have been performed at Reynolds numbers (Re) 4000 and 5000. The SHS comprised of streamwise or azimuthal microgrooves (MG), spanwise or longitudinal MG, grooves inclined to the streamwise direction (spiral), and microposts. The SHS have been modeled as shearfree areas. We were able to achieve a maximum DR up to 34% for the streamwise aligned SHS, while we got drag enhancement of 4% for the spiral SHS at η = 0.67. The SHS cause slip at the wall as well as near-wall turbulence modification, both governing the DR. We have tried to understand the role of the effective slip and modified turbulence dynamics responsible for DR b.
Electronic, structural and vibrational properties of calcium monohydride

Thanks to the quantum chemistry approach, a global study has been performed for numerous excited electronic states of calcium monohydride denoted CaH. The CaH molecule is considered as a three effective electrons system. It was treated on the Multireference Configuration Interaction level of theory using the effective core potentials including Core Polarization Potential operator with large Gaussian basis sets. Hence, the Potential Energy Curves (PECs) for 2,4∑+, 2,4∏ and 2,4Δ symmetries have been determined. These curves exhibit an attracted behavior in the avoided crossings region due to the strong interactions between Ca and H. Then, their relative spectroscopic constants have been calculated by solving the vibrational Schrödinger equation using the PECs. Finaly, the vibrational properties and the electric dipole moments of CaH have been investigated and analyzed in detail.
Chiral molecules-ferromagnetic interfaces, an approach towards spin controlled interactions

Chiral symmetry is ubiquitous in Biology, Physics, and Chemistry. The biomolecules essential for life on Earth—such as deoxyribonucleic acid (DNA), sugars, and proteins—display homochirality that affects their function in biological processes. Ten years ago, it was discovered that electron transfer through chiral molecules depends on the direction of the electron spin, and more recently, it was shown that the charge displacement in chiral molecules creates transient spin polarization. Thus, the properties of ferromagnet/chiral molecule interfaces are affected by spin exchange interactions, via the overlap of the chiral molecule with the ferromagnet's spin wave function. This effect offers a mechanism for homochiral bias in Biology, which was previously unappreciated, and an approach to enantioselective chemistry and chiral separations, which is controlled by the electron spin.