Real-time detection and tracking of multiple objects with partial decoding in H.264/AVC bitstream domain

In this paper, we show that we can apply probabilistic spatiotemporal macroblock filtering (PSMF) and partial decoding processes to effectively detect and track multiple objects in real time in H.264|AVC bitstreams with stationary background. Our contribution is that our method cannot only show fast processing time but also handle multiple moving objects that are articulated, changing in size or internally have monotonous color, even though they contain a chaotic set of non-homogeneous motion vectors inside. In addition, our partial decoding process for H.264|AVC bitstreams enables to improve the accuracy of object trajectories and overcome long occlusion by using extracted color information.Comment: SPIE Real-Time Image and Video Processing Conference 200

Numerical analysis of the elastic-plastic behavior of a tubular structure in FGM under pressure and defect presence

Given the field of application and the many advantages, the use of FGM (Functionally Graded Materials) materials has recently been extended in several components and more particularly in cylindrical structures, which have been the subject of several recent studies. Our work aims to use the finite element method to analyze a cylindrical structure in FGM with properties gradated in the direction of the radius (Thickness) solicited purely in internal pressure by the implementation of a UMAT subroutine in the calculation code ABAQUS. The elasto-plastic behavior of the FGM is described by the flow theory represented by the equivalent stress of Von Mises and an incremental hardening variable. The TTO model (Tamura-Tomota-Ozawa) was used only to determine the elastic-plastic properties of the FGM material. The radial, tangential and axial stresses according to the thickness were evaluated in the first part of our work. In the second part, these stresses are evaluated under the same conditions but with the presence of a micro-cavity. The results obtained show clearly that these stresses are in direct relation not only with the thickness and properties of the FGM tube but also with the presence of the cavity

Spondylodiscite tuberculeuse compliquée d’une ischémie aigue des membres inférieurs - à propos d’un cas

Les complications thromboemboliques associées à l´infection par Mycobacterium tuberculosis ont été rapportées dans la littérature et ont eu lieu dans 1,5 à 3,4% de l´infection tuberculeuse. Nous rapportons le cas d’une fillette âgée de 4ans suivie pour spondylodiscite tuberculeuse, admise dans notre formation pour prise en charge d’une ischémie aigue des deux membres inférieurs consommée, ayant nécessité une amputation transtibiale d’un côté et trans-fémorale du coté contro-latéral. Nous discutons les aspects cliniques, physiopathologiques et le lien de causalité.Key words: Thrombose, artère, tuberculose, ischémi

Numerical Simulation of the Mechanical Response of the Tunnels in the Saturated Soils by Plaxis

The forecast of settlement and movements caused by tunneling represents a significant challenge of technology. The evaluation of these movements is indeed of primary importance in order to prevent them. The methods of calculation making it possible to evaluate displacements and deformations in the ground due to tunneling give only one approximation of the true amplitudes of the movements in the ground. It is one of the assets of the Finite Element Method (FEM) which makes it possible a priori to treat configurations more complex and closer to reality. Our objective in this study is to calculate numerically the various movements caused by the construction of a shallow tunnel using a shield using PLAXIS 2D, the behavior of the ground is described by a perfectly plastic elastic model based on the criterion of Mohr-Coulomb. A comparison between the various methods: empirical, analytical and numerical in terms of settlement on the surface was carried out. The validation of these results was made by using results drawn from literature. We have also carried out a parametric study in order to analyze the influence of various geometrical and geotechnical parameters on the behavior of grounds due to tunneling. Lastly, we have treated the same example by supposing the existence of structures near the tunnel in order to see the influence of the presence of other structures on the profile of the settlements caused by tunneling. Results of our work agreed with those in literature

PID vs LQR controller for tilt rotor airplane

The main thematic of this paper is controlling the main manoeuvers of a tilt rotor UAV airplane in several modes such as vertical takeoff and landing, longitudinal translation and the most important phase which deal with the transition from the helicopter mode to the airplane mode and visversa based on a new actuators combination technique for specially the yaw motion with not referring to rotor speed control strategy which is used in controlling the attitude of a huge number of vehicles nowadays. This new actuator combination is inspired from that the transient response of a trirotor using tilting motion dynamics provides a faster response than using rotor speed dynamics. In the literature, a lot of control technics are used for stabilizing and guarantee the necessary manoeuvers for executing such task, a multiple Attitude and Altitude PID controllers were chosen for a simple linear model of our tilt rotor airplane in order to fulfill the desired trajectory, for reasons of complexity of our model the multiple PID controller doesnt take into consideration all the coupling that exists between the degrees of freedom in our model, so an LQR controller is adopted for more feasible solution of complex manoeuvering, the both controllers need linearization of the model for an easy implementation

Numerical study of the effect of the structural disorder on the electronic properties in disordered solids

During the last few years, it became clear that the characterization of the nature of electron states in disordered systems is one of the fundamental topics in condensed matter physics. Along these lines, our present work consists of the study of the effect of the structural disorder on a wide range of electronic properties (density of electron states, participation ratio of electron states and distribution of energy levels). For this, we generate the structural disorder according to three different models: a model named "Shaken lattice’’, a model simulated by molecular dynamics and the model of the random triangles. Concerning the Hamiltonian model, we use a Tight-Binding model with explicit S-type orbitals for the first two structures and a clean Tight-Binding model for the model of the random triangles. Our results show that electron states are localized or delocalized depending on the type of the structural disorder used to generate a particular topologically disordered system.During the last few years, it became clear that the characterization of the nature of electron states in disordered systems is one of the fundamental topics in condensed matter physics. Along these lines, our present work consists of the study of the effect of the structural disorder on a wide range of electronic properties (density of electron states, participation ratio of electron states and distribution of energy levels). For this, we generate the structural disorder according to three different models: a model named "Shaken lattice’’, a model simulated by molecular dynamics and the model of the random triangles. Concerning the Hamiltonian model, we use a Tight-Binding model with explicit S-type orbitals for the first two structures and a clean Tight-Binding model for the model of the random triangles. Our results show that electron states are localized or delocalized depending on the type of the structural disorder used to generate a particular topologically disordered system

Impact of land use changes on soil resources degradation in southern Rif Central, Morocco

Dans le Rif central au nord du Maroc, les écosystèmes forestiers ont subi une régression très forte au profit des zones agricoles. L’installation de la culture du cannabis au détriment de la forêt illustre les rôles importants des forêts sur le plan environnemental, économique et social. L’objectif de ce travail consiste à évaluer et à quantifier l’impact de l’évolution de l’utilisation des terres sur la dégradation des sols dans le Rif Central méridional. La perte de fertilité des sols défrichés a été évaluée à l'aide d'analyses physico-chimiques après 2, 6, 10 et 22 ans de mise en culture. Une simulation manuelle de précipitation a été utilisée pour évaluer l'impact du défrichement suivi de la mise en culture sur le comportement hydrodynamique du sol. Les résultats obtenus montent que la conversion des forêts en zones agricoles ont des conséquences multiples sur le milieu naturel. Le sol devient instable sous les effets des labours successifs qui conduisent à une réduction importante des réserves du sol ; au bout de 22 ans de mise en culture, la matière organique a diminué de 73% de sa teneur initiale et le taux de l’azote s’est réduit de -60%, l’acidité a augmenté d’une unité. Les pertes en sols par l'érosion hydrique ont été évaluées à 3,2 t/ha pour une séquence de précipitation de 80 mm h-1 pendant 45 minutes. Cette dégradation entrave la productivité agricole, ce qui amène les agriculteurs à abandonner ces terres et à chercher de nouvelles parcelles au détriment des forêts pour satisfaire leurs besoins en terres agricoles. Mots clés: Utilisation des terres, Réserves de sol, Érosion hydrique, Rif central, MarocIn the Central Rif in the north of Morocco, forest ecosystems have suffered a very sharp decline in favor of crops. The installation of agriculture at the expense of forests illustrates the important roles of forests on the environmental, economic and social levels. The objective of this work is to assess and quantify the impact of land-use change on land degradation in the southern Central Rif. The loss of fertility of cleared soils was assessed using physico-chemical analyses after 2, 6, 10 and 22 years of cultivation. A manual rainfall simulation was used to assess the impact of clearing followed by cultivation on the hydrodynamic behavior of the soil. The results show that the conversion of forests into agricultural areas has multiple consequences on the natural system. The soil becomes unstable under the effects of successive ploughing which leads to a significant reduction in soil reserves; organic matter decreased by 73% of its initial content and the nitrogen rate decreased by -62.5%, acidity increased by one unit after 22 years of cultivation. Soil losses were estimated at 1126,8 g m-2 h-1 for a precipitation sequence of 80 mm h-1 for 45 minutes. This degradation hinders agricultural productivity, leading farmers to abandon the land and seek new plots at the expense of forests to meet their agricultural land needs. Keywords: Land use, Soil reserves, Water erosion, Central Rif, Morocc

Adaptive Reference Trajectory for Power Quality Enhancement in Three-Phase Four-Wire Standalone Power Supply Systems with Nonlinear and Unbalanced Loads

International audienc

Controlling palladium morphology in electrodeposition from nanoparticles to dendrites via the use of mixed solvents

By changing the mole fraction of water (χwater) in the solvent acetonitrile (MeCN), we report a simple procedure to control nanostructure morphology during electrodeposition. We focus on the electrodeposition of palladium (Pd) on electron beam transparent boron-doped diamond (BDD) electrodes. Three solutions are employed, MeCN rich (90% v/v MeCN, χwater = 0.246), equal volumes (50% v/v MeCN, χwater = 0.743) and water rich (10% v/v MeCN, χwater = 0.963), with electrodeposition carried out under a constant, and high overpotential (−1.0 V), for fixed time periods (50, 150 and 300 s). Scanning transmission electron microscopy (STEM) reveals that in MeCN rich solution, Pd atoms, amorphous atom clusters and (majority) nanoparticles (NPs) result. As water content is increased, NPs are again evident but also elongated and defected nanostructures which grow in prominence with time. In the water rich environment, NPs and branched, concave and star-like Pd nanostructures are now seen, which with time translate to aggregated porous structures and ultimately dendrites. We attribute these observations to the role MeCN adsorption on Pd surfaces plays in retarding metal nucleation and growth