Miracle-dz/UniFAR-FTUs huggingface dataset:
Motivation Factors For Young Basketballers In Aso Modele And Elan Sportif Clubs

: The objective of this research is to study the factors that motivate young basketball players from Aso Modèle and Elan sportif. For this purpose, a mixed survey was conducted among 31 subjects, including 27 young basketball players and 4 coaches, to study the factors that motivate young people to play basketball in both clubs and to analyze the motivation of young people in both clubs; to this end, the theory of self-determination of Déci and Ryan (2002) was used. Thus, we were able to show that the age of the respondents is between 14 and 20 years old (18.00 ± 1.76); results have been obtained that reveal that Aso Modèle players are more intrinsically motivated to achieve while Elan players are more interested in maintaining good relationships with friends (extrinsic motivation with external regulation); and that the motivation of young basketball players varies from one club to another. It was suggested that coaches should take into account the motivation of young people in order to find ways and methods to increase it; in this way, these young people will not only produce better performance but will also be loyal to the club.
Intraseasonal variability of the West African monsoon

The intraseasonal time scale is critical in West Africa where resources are highly rainfall dependent. Three main modes of variability have been identified, two with a mean periodicity of 15 days and one with a mean periodicity around 40 days. These modes have a regional scale and can strongly influence precipitation and convective activity. They are mainly controlled by atmospheric dynamics and land–surface interactions. They can also modulate the very specific phase of the African summer monsoon onset. A better knowledge of the mechanisms controlling this scale is necessary to improve its predictability. Copyright © 2010 Royal Meteorological Society
Le défaut d’approximation forte pour les groupes algébriques commutatifs

Resume. On etablit une suite exacte decrivant l’adherence des points rationnels d’un 1-motif dans ses points adeliques. On en deduit ensuite que le defaut d’approximation forte pour un groupe algebrique commutatif G est essentiellement mesure par son groupe de Brauer algebrique via l’obstruction de Brauer-Manin entiere. Abstract. We give an exact sequence describing the closure of the set of rational points of a 1-motive in its adelic points. From this we deduce that for a commutative algebraic group, the defect of strong approximation is essentially controlled by its algebraic Brauer group, by means of the integral Brauer-Manin obstruction. Mots-cles. Approximation forte, Groupe de Brauer, 1-motif.
Self-triggered control for multi-agent systems with unknown non-linear inherent dynamics

This study focuses on the design of self-triggered controls for first-order multi-agent systems with unknown inherent non-linear dynamics. First, conditions that guarantee the existence of a self-triggered control are provided to solve the consensus problem under fixed communication topologies if the graph has a directed spanning tree. Then, self-triggered strategy under switching communication topologies is studied using polynomial approximations of multiple Lyapunov functions. A methodology for the computation of the feedback gain and the control update time is given. Simulation results show the effectiveness of the proposed strategy.
Delayed reflection of the energy flow at a potential step for dispersive wave packets

We study Klein–Gordon equations with constant coefficients and different dispersion relations on two one‐dimensional semi‐infinite media coupled with transmission conditions. We obtain lower and upper bounds of the reflected part of the energy flow at the connecting point when the frequency band involved in the initial signal is sufficiently narrow. We detect a phenomenon of delayed reflection for low frequency wave packets, which is in accordance with the recent experiments of Haibel and Nimtz. The result is then generalized for a star‐shaped network of n semi‐infinite branches connected at one point. Copyright © 2004 John Wiley & Sons, Ltd.
A time-dependent model for reactive sputter deposition

A time-dependent, spatially resolved model (RSD2013) for dc reactive magnetron sputtering is proposed. The model includes several processes such as reactive gas chemisorption on the target and the substrate, direct and knock-on implantation of reactive species in the target, subsurface compound formation in the target, the deposition of sputter material on the substrate and redeposition of sputtered material back on to the target. A full derivation and motivation of the model is given. This formulation of the model is contained within the software RSD2013, a user-friendly simulation tool for the reactive sputter process. To demonstrate this tool, a time-dependent simulation of a realistic system with an increasing number of available RSD2013 options is discussed.
Invariant Submeans and Semigroups of Nonexpansive Mappings on Banach Spaces with Normal Structure

Abstract In this paper we study the relation between invariant submean and normal structure in a Banach space. This is used to give an improvement and different proof of a fixed point theorem of Lim (also of Belluce and Kirk for commutative semigroups) for left reversible semigroup of nonexpansive mappings on weakly compact convex subsets of a Banach space with normal structure.
A Model of the Early Visual System Based on Parallel Spike-Sequence Detection, Showing Orientation Selectivity

Simple Summary A computational model of primates’ early visual processing, showing orientation selectivity, is presented. The system importantly integrates two key elements: (1) a neuromorphic spike-decoding structure that considerably resembles the circuitry between layers IV and II/III of the primary visual cortex, both in topology and operation; (2) the plasticity of intrinsic excitability, to embed recent findings about the operation of the same area. The model is proposed as a tool for the analysis and reproduction of the orientation selectivity phenomenon, whose underlying neuronal-level computational mechanisms are today the subject of intense scrutiny. In response to rotated Gabor patches the model is able to exhibit realistic orientation tuning curves and to reproduce responses similar to those found in neurophysiological recordings from the primary visual cortex obtained under the same task, considering different stages of the network. This demonstrates its aptness to capture the mechanisms underlying the evoked response in the primary visual cortex. Our tool is available online, and can be expanded to other experiments using a dedicated software library developed by the authors, to elucidate the computational mechanisms underlying orientation selectivity. Abstract Since the first half of the twentieth century, numerous studies have been conducted on how the visual cortex encodes basic image features. One of the hallmarks of basic feature extraction is the phenomenon of orientation selectivity, of which the underlying neuronal-level computational mechanisms remain partially unclear despite being intensively investigated. In this work we present a reduced visual system model (RVSM) of the first level of scene analysis, involving the retina, the lateral geniculate nucleus and the primary visual cortex (V1), showing orientation selectivity. The detection core of the RVSM is the neuromorphic spike-decoding structure MNSD, which is able to learn and recognize parallel spike sequences and considerably resembles the neuronal microcircuits of V1 in both topology and operation. This structure is equipped with plasticity of intrinsic excitability to embed recent findings about V1 operation. The RVSM, which embeds 81 groups of MNSD arranged in 4 oriented columns, is tested using sets of rotated Gabor patches as input. Finally, synthetic visual evoked activity generated by the RVSM is compared with real neurophysiological signal from V1 area: (1) postsynaptic activity of human subjects obtained by magnetoencephalography and (2) spiking activity of macaques obtained by multi-tetrode arrays. The system is implemented using the NEST simulator. The results attest to a good level of resemblance between the model response and real neurophysiological recordings. As the RVSM is available online, and the model parameters can be customized by the user, we propose it as a tool to elucidate the computational mechanisms underlying orientation selectivity.
Fresnel’s formulae and the Minkowski momentum

It is shown that the momentum of an electromagnetic wave in a dielectric medium can be uniquely determined to be the Minkowski momentum by considering oblique incidence of electromagnetic wave on a flat dielectric boundary. The Minkowski momentum is consistent with the Fresnel’s formulae and satifies the energy and momentum conservation laws.
The equilibrium states and the stability analysis of Reynolds stress equations for homogeneous turbulent shear flows

An analysis is performed to examine the equilibrium states and the stability of modeled Reynolds stress equations for homogeneous turbulent shear flows. The system of the governing equations consists of four coupled ordinary differential equations for b11, b22, b12, and e/Sk. Depending on the model constants adopted, the solution of this system may converge, diverge, oscillate, or the equilibrium solution may not exist. It is shown that the rapid part of the pressure–strain correlation is most responsible for such different behaviors. Constraints for the model constants in various Reynolds stress models are obtained by stability conditions for the equilibrium states as well as by their physically realizable bounds. It is observed that most models for the pressure–strain correlation that are linear in the anisotropy tensor are stable and produce reasonable equilibrium solutions. Whereas quadratic or cubic models often oscillate and converge onto unrealistic states, especially under high shear conditions.
The area preserving curve shortening flow with Neumann free boundary conditions

Abstract We study the area preserving curve shortening flow with Neumann free boundary conditions outside of a convex domain in the Euclidean plane. Under certain conditions on the initial curve the flow does not develop any singularity, and it subconverges smoothly to an arc of a circle sitting outside of the given fixed domain and enclosing the same area as the initial curve.
The crack growth prediction in homogeneous materials and bimaterial systems

The new criterion determining the angle of crack propagation in mixed mode loading conditions is proposed. Both monotonic and cyclic loading are considered for homogeneous and bimaterial systems. For bimaterial it is assumed that either the crack does not touch or simply crosses the interface during its growth. The angle of the crack propagation corresponds with the direction where the ratio of the dissipation energy generated in the plastic processes to that generated in the decohesion processes reaches its smallest value. The criterion assumes also that the fracture crack propagation follows the direction for which the distortional component of the strain energy density, TD calculated along the line of the constant dilatation energy density TVC around the crack tip reaches its minimum value. The constant value of TVC is associated with the ultimate tensile stress σC. The criterion involves the T‐stress term that represents a constant stress parallel to the main crack orientation. A critical length of the radius of the decohesion zone determines the fracture condition. In the article a numerical method based on the singular integral technique involving the distribution of edge dislocations to represent the actual crack is proposed. The resulting singular integral equations with Cauchy‐type singularities are solved numerically. The method allows us to determine the stress intensity factors (SIFs) and T‐stress term at the tips of the propagating crack. The results show very good agreement with the numerical data found in the literature. The new equation to determine the fatigue crack growth rate is also proposed and used to trace the fatigue crack path in the homogeneous and bimaterial systems.
An Order-Disorder Transformation Phenomenon in the FeTiO 3 –Fe 2 O 3 Solid Solution Series

The effects of heat treatments on the magnetic properties of the synthesized solid solution x FeTiO 3 –(1- x )Fe 2 O 3 of ilmenite and hematite were examined in detail for compositions x around 0.5. It was confirmed that a transformation from an ordered state (ferrimagnetic one) into a disordered state (antiferromagnetic one) takes place cooperatively at a distinct transition point. This transformation temperature is lowered with decrease in the ilmenite content from 1100°C for x =0.65 to 600°C for x =0.45. The completely disordered specimens could not be obtained for the composition x ≧0.6 by the quench method while the completely ordered state could not be attained in the specimens with x ≦0.5 because of decrease of the transformation temperature for these specimens and a reduction of the rate of ion diffusion at such low temperatures. The results obtained were discussed by using the Bragg-Williams approximation. It was noted briefly that the reverse thermo-remanent magnetism found in this system is clo.
Elongated CO structure in the starburst galaxy NGC 2146

Observations of NGC 2146, obtained in the 115.272-GHz J = 1-0 transition of CO with spatial and velocity resolution of 6 arcsec and 52 km/s (respectively) using the Hat Creek Millimeter Interferometer during January and February 1987, are reported. The data are presented in maps and characterized in detail. An elongated (3.0 x 0.7 kpc) structure consisting of CO at 10 K or warmer and having a velocity gradient of 0.2 km/s pc along its length is detected at the location of the radio continuum emission (not identical to the optical dust lane) and tentatively attributed to an edge-on bar or disk. From the IR/CO luminosity ratios it is inferred that NGC 2146 has starburst activity similar to that of M 82 but on a larger scale. 25 references.
Time‐resolved reflectivity of ion‐implanted silicon during laser annealing

The time‐resolved reflectivity at 0.63 μm from arsenic‐implanted silicon crystals has been measured during annealing by a 1.06‐μm laser pulse of 50‐ns duration. The reflectivity was observed to change abruptly to the value consistent with liquid silicon and to remain at that value for a period of time which ranged from a few tens of nanoseconds to several hundreds of nanoseconds, depending on the annealing pulse intensity. Concurrently, the transmission of the primary annealing beam dropped abruptly. These observations confirm the formation of a metallic liquid phase at the crystal surface during the annealing process.
CRACK PROPAGATION IN FLEXURAL FATIGUE OF CONCRETE

In this paper the behavior of concrete subjected to flexural fatigue loading is studied. Notched concrete beams were tested in a three-point bending configuration. Specimens were subjected to quasi-static cyclic and constant amplitude fatigue loading. The cyclic tests were performed by unloading the specimen at different points in the postpeak part of the quasi-static loading response. Low cycle, high amplitude fatigue tests were performed to failure using four different load ranges. The crack mouth opening displacement was continuously monitored throughout the loading process. Crack propagation caused by quasi-static and fatigue loads is described in terms of fracture mechanics. It is shown that the crack propagation in the postpeak part of the quasi-static load response is predicted using the critical value of the mode I stress intensity factor (\IK\DIC\N). The ultimate deformation of the specimen during the fatigue test is compared with that from the quasi-static test; it is demonstrated that the quasi-static deformation is insufficient as a fatigue failure criterion. It is observed that crack growth owing to constant-amplitude fatigue loading comprises two phases: a deceleration stage where there is a decrease in crack growth rate with increasing crack length, followed by an acceleration stage where the rate of crack growth increases at a steady rate. The crack length where the rate of crack growth changes from deceleration to acceleration is shown to be equal to the crack length at the peak load of the quasi-static response. Analytical expressions for crack growth in the deceleration and acceleration stages are developed, wherein the expressions for crack growth rate in the deceleration stage are developed using the \iR-curve concept, and the acceleration stage is shown to follow the Paris law. It is observed that the crack length at failure for constant amplitude fatigue loading is comparable to that of the corresponding load in the postpeak part of the quasi-static response. Finally, a fracture-based fatigue failure criterion is proposed.
Investigation of the electric field distribution in x-ray detectors by Pockels effect

In x- and γ-ray semiconductor detectors, the distribution of the internal electric field strongly affects their charge-collection properties. In planar detectors, the electric field distribution depends not only on the semiconductor characteristics, but mainly on the nature of the electrical contacts. This is an issue in CdTe and CdZnTe (CZT) detectors, where many efforts have been devoted to the study and the improvement of contacts, with the aim of suppressing dark current to low values and enhancing the collection of the photo-generated carriers. This work explores the effect of recently developed electrodes for CdTe detectors on the internal electric field distribution by exploiting the voltage-induced birefringence, which is shown by zincblende-structured materials such as CdTe. We used the transverse Pockels effect, in which near-infrared radiation impinges on the side of the CdTe detector parallel to the contact planes, and therefore perpendicular to the electric field. The implemented set-up and the procedure to reconstruct the electric field distribution is presented. The system allows us to extract maps of the electric field with a good spatial resolution, and to study its dependence on the applied voltage. The use of the Pockels effect appears to be a powerful tool, not only to gain information on the electric field, but also to analyse the time evolution observed, at room temperature, in the performance of these detectors.
Billiard systems on quadric surfaces and the Poncelet theorem

Billiard systems constrained to move on a quadric surface with confocal quadric boundaries were studied. The trajectory of a billiard is described as a collection of geodesic segments joining on the boundary. At the joining points, the trajectory obeys the law of reflection. It was found that the geodesic segments are all tangent to a common confocal quadric curve (a caustic) on this quadric surface. If a trajectory is closed, then all trajectories sharing the same caustic quadric are all closed and have the same period and length. Thus a generalization of Poncelet’s theorem on a quadric surface is achieved. The elliptical billiard systems on spheres and pseudospheres were studied and results were obtained that are similar to those on a plane. The results can be extended to n dimensions.
Measurements and predictions for nonevaporating sprays in a quiescent environment

Yule et al. (1982) have conducted a study of vaporizing sprays with the aid of laser techniques. The present investigation has the objective to supplement the measurements performed by Yule et al., by considering the limiting case of a spray in a stagnant environment. Mean and fluctuating velocities of the continuous phase are measured by means of laser Doppler anemometry (LDA) techniques, while Fraunhofer diffraction and slide impaction methods are employed to determine drop sizes. Liquid fluxes in the spray are found by making use of an isokinetic sampling probe. The obtained data are used as a basis for the evaluation of three models of the process, including a locally homogeneous flow (LHF) model, a deterministic separated flow (DSF) model, and a stochastic separated flow (SSF) model. It is found that the LHF and DSF models do not provide very satisfactory predictions for the test sprays, while the SSF model does provide reasonably good predictions of the observed structure.
The structure of the dissipation region for component reconnection: Particle simulations

Results from a kinetic simulation of component reconnection are presented. Reconnection proceeds in a current sheet with 104 degrees magnetic field rotation. As a result, magnetic reconnection forms distinctively different signatures from what was found from kinetic models of anti‐parallel reconnection. In particular, ion and electron flow patterns are substantially distorted, the shear magnetic field component does not exhibit a quadrupolar structure, and electron orbits in the diffusion region are substantially modified. The emphasis of the investigation is on the modifications to the diffusion region, with particular emphasis on the electron diffusion zone. Electron pressure nongyrotropies can support collisionless magnetic reconnection even when electron motion in diffusion region is strongly affected by the guide magnetic field.
A Numerical Solution for an Inverse Natural Magneto-Convection Problem

An inverse boundary-value problem arising in natural magneto-convection is formulated and investigated numerically for the first time. The physical problem takes place in a square cavity whose boundary contains a left hostile wall on which no boundary condition can be prescribed or measured and a right accessible wall on which two boundary conditions, i.e., boundary temperature and heat flux data, are overspecified. A novel algorithm, based on a regularized dual-reciprocity boundary-element method (DRBEM), is presented. Accurate and stable numerical results at various convective Rayleigh and magnetic Hartmann numbers are reported for retrieving a discontinuous time-varying step heat flux in one example, and a uniform boundary temperature in the second example.
Mass transport mechanisms in partially stratified estuaries

A number of mechanisms which transport dissolved constituents and maintain the salt balance in estuaries are described. Although some of these have already been analysed, two which appear to be the most important in many real estuaries have received little previous attention. The Mersey Estuary is used as an example in which to estimate the amount of mass transported by each mechanism. The computations show in part how little is known and how much hypothesis is still required in spit? e of the number of previous estuarine studies; one may conclude, however, that in many real estuaries the most important mass transport mechanism is the net (non-tidal) transverse circulation, which is induced in part by the boundary geometry and in part by the longitudinal density gradient.
Ultrafast phase-resolved pump-probe measurements on a quantum cascade laser

The dynamics of optical gain in an InGaAs/AlInAs quantum cascade laser is studied in midinfrared pump-probe measurements. Pump and probe pulses of identical wavelength, polarization, and propagation direction through the laser waveguide are detected separately by electro-optic sampling. For injection currents below the lasing threshold, we observe an absorption decrease in the laser transition with a ≈3 ps recovery time. Above threshold, the gain strongly saturates and shows a fast recovery time decreasing with current. Such kinetics is superimposed by oscillations with a frequency of 0.8 THz originating from coherent electron tunneling through the injection barrier.