EBP: An Efficient Broadcast Protocol for Warning Message Dissemination in VANETs

Vehicular Ad-hoc Networks (VANETs) enable vehicle-to-vehicle communications to share relevant road information with various applications. Road safety is one of the main objectives of VANETs that has attracted great interest from researchers. Other so-called comfort applications have also been studied which can improve driving experience and passenger safety. In all these applications, sharing of warning messages can help drivers minimize accidents and congestions, and plan better itinerary during the congestion situations or the anticipation of potential and highly hazardous events. In this paper, we present an efficient broadcast protocol (EBP) for broadcasting warning messages in VANETs. As an improved strategy for alert data dissemination, EBP can be applied in whatever the nature of the risk, with a particular focus on mobile dangers. We first conduct an in-depth analysis and evaluation, under different conditions, of the existing approaches and mechanisms used for information dissemination in VANETs. Then, we point out their drawbacks and design the EBP to avoid these drawbacks. As a result, the EBP is an improved, well-justified and more effective protocol. We validate it by simulation experiments under various scenarios

Effect of cement types on carbonation depth of concrete

Reinforced concrete as a building material is the most used in most civil engineering structures. This one is exposed to several attacks (physical, chemical and mechanical). Among these attacks, we can cite the phenomenon of carbonation, which leads to corrosion of the reinforcements and consequently reduces the service life of reinforced concrete structures. In addition, this phenomenon generates additional repair costs, which can sometimes exceed the initial cost of the building. Furthermore, it depends on the type and class of cement, two main classes of cement are used for the formulation of concrete in Algeria, ordinary Portland cements and cements with additions.  This paper enters in the option of sustainable development, in order to study the behavior of these two types of cements against accelerated carbonation. For this purpose, two concrete compositions (based on ordinary Portland cements and cements with additions) were formulated, from these two formulations, samples were made in order to subject them to accelerated carbonation in a chamber rich in CO2 according to the recommendations of the AFPC-AFREM. The results obtained clearly show that concretes based on ordinary Portland cements (OPC) are less sensitive to the phenomenon of carbonation compared to concretes based on blended cements. &nbsp

Survey on QoE/QoS Correlation Models for Video Streaming over Vehicular Ad-hoc Networks

Vehicular Ad-hoc Networks (VANETs) are a new emerging technology which has attracted enormous interest over the last few years. It enables vehicles to communicate with each other and with roadside infrastructures for many applications. One of the promising applications is multimedia services for traffic safety or infotainment. The video service requires a good quality to satisfy the end-user known as the Quality of Experience (QoE). Several models have been suggested in the literature to measure or predict this metric. In this paper, we present an overview of interesting researches, which propose QoE models for video streaming over VANETs. The limits and deficiencies of these models are identified, which shed light on the challenges and real problems to overcome in the future

Modélisation des interactions de coopération dans la conduite d'un projet de simulation

International audienceThis study was carried out within the framework of a research project entitled «CSCW and Simulation: Toward a group-oriented platform of analysis and design of production systems». The object of this project is to analyze the cooperation practices during the conduct of a project of modeling and simulation of a production system, then to specify and develop a simulation groupware with an aim of adding the group dimension to simulation tools. In this paper, we define and we present a modeling of cooperation interactions in the conduct of cooperative simulation project using the Denver Model. We illustrate our approach by presenting our experiment with BSCW system to validate our modeling

EBP: An Efficient Broadcast Protocol for Warning Message Dissemination in VANETs

Vehicular Ad-hoc Networks (VANETs) enable vehicle-to-vehicle communications to share relevant road information with various applications. Road safety is one of the main objectives of VANETs that has attracted great interest from researchers. Other so-called comfort applications have also been studied which can improve driving experience and passenger safety. In all these applications, sharing of warning messages can help drivers minimize accidents and congestions, and plan better itinerary during the congestion situations or the anticipation of potential and highly hazardous events. In this paper, we present an efficient broadcast protocol (EBP) for broadcasting warning messages in VANETs. As an improved strategy for alert data dissemination, EBP can be applied in whatever the nature of the risk, with a particular focus on mobile dangers. We first conduct an in-depth analysis and evaluation, under different conditions, of the existing approaches and mechanisms used for information dissemination in VANETs. Then, we point out their drawbacks and design the EBP to avoid these drawbacks. As a result, the EBP is an improved, well-justified and more effective protocol. We validate it by simulation experiments under various scenarios

Vulnérabilité des ouvrages hydrauliques à travers l’érosion interne. Modélisation d’un écoulement diphasique érodant dans un milieu poreux

International audienceInternal erosion is one of the main causes of ruptures in hydraulic works. It can be developed under the form of two basic phenomena: piping erosion and suffusion, they differ in their geometrical and Hydraulic boundary conditions. The risk of rupture is consequently different. The first phenomenon is the most dangerous and fastest if it is not immediately stopped; it leads (drove) very quickly to failure. In the second, the permeability of the medium is slowly modified and after an uninterrupted phase of development, there (can) may be ruptured. Relying on a Darcyflow and law erosion of Papamichos and a law of evolution of the viscosity fluid (Einstein relation), we propose a first approach for modeling the suffusion by the description of the evolution in time of the average porosity of the matrix solid porous medium, the concentration of fluid particles eroded, as well as the evolution of the mass of particles eroded while highlighting the influence of changes in hydraulic and mechanical parameters of the ground on this development as that the coefficient of erosion, the maximum porosity ... etc. The numerical solution of the problem is done by the method of finite differences. The sample is discretized into a set of elementary layers. The basic layer is referenced by the index j and the time by exposing i. For the discretization, we adopted the explicit scheme decentered. The simulation results indicate thatThe suffusion phenomenon is strongly related to hydraulic and mechanical parameters of soil like the erosion coefficientλ and the final porosity max.. Our work is based on the realization of software using Matlab to study the static or dynamic, linear, and rotary electric machines and more particularly the squirrel cage induction motor. These machines are the most common versions of classic electrical machines in every energy system. In this paper, we focus on the implementation of the LEC_RBR software developed in the Electrotechnical Laboratory of Constantine for the determination of the electrical and magnetic quantities in the squirrel cage induction motorL'érosion interne est l'une des causes principales de rupture des ouvrages hydrauliques. Elle peut être développée sous forme de deux phénomènes fondamentaux à savoir le renard hydraulique et la suffusion, ils diffèrent par leurs conditions aux limites géométriques et hydrauliques, le risque de rupture est en conséquence différent. Le premier phénomène est le plus dangereux et le plus rapide, s'il n'est pas immédiatement stoppé, il conduit très rapidement à la rupture. Dans le second, la perméabilité du milieu est lentement modifiée et après une phase de développement ininterrompue, il peut y avoir rupture. En se basant sur une loi d'écoulement type Darcy et une loi d'érosion de Papamichos et enfin une loi d'évolution de la viscosité de fluide (relation d'Einstein), nous proposons une première approche de modélisation de la suffusion, par la mise en évidence de l'évolution dans le temps de la porosité moyenne de la matrice solide du milieu poreux, de la concentration du fluide en particules érodées, ainsi que l'évolution de la masse des particules érodées, tout en mettant en évidence l'influence de la variation des paramètres mécaniques et hydrauliques du sol sur cette évolution tel que le coefficient d'érosion, la porosité maximale ...etc. La résolution numérique du problème est réalisée par la méthode des différences finies. L'échantillon étudié est discrétisé en un ensemble de couches élémentaires. La couche élémentaire est référencée par l'indice j et l'instant par l'exposant i. Pour la discrétisation, on a adopté le schéma explicite décentré. Les résultats de simulation indiquent que le phénomène de suffusion est fortement lié aux paramètres mécaniques et hydrauliques du sol à savoir le coefficient d'érosion λ, la porosité finale Ømax

Vulnérabilité des ouvrages hydrauliques à travers l’érosion interne. Modélisation d’un écoulement diphasique érodant dans un milieu poreux

International audienceInternal erosion is one of the main causes of ruptures in hydraulic works. It can be developed under the form of two basic phenomena: piping erosion and suffusion, they differ in their geometrical and Hydraulic boundary conditions. The risk of rupture is consequently different. The first phenomenon is the most dangerous and fastest if it is not immediately stopped; it leads (drove) very quickly to failure. In the second, the permeability of the medium is slowly modified and after an uninterrupted phase of development, there (can) may be ruptured. Relying on a Darcyflow and law erosion of Papamichos and a law of evolution of the viscosity fluid (Einstein relation), we propose a first approach for modeling the suffusion by the description of the evolution in time of the average porosity of the matrix solid porous medium, the concentration of fluid particles eroded, as well as the evolution of the mass of particles eroded while highlighting the influence of changes in hydraulic and mechanical parameters of the ground on this development as that the coefficient of erosion, the maximum porosity ... etc. The numerical solution of the problem is done by the method of finite differences. The sample is discretized into a set of elementary layers. The basic layer is referenced by the index j and the time by exposing i. For the discretization, we adopted the explicit scheme decentered. The simulation results indicate thatThe suffusion phenomenon is strongly related to hydraulic and mechanical parameters of soil like the erosion coefficientλ and the final porosity max.. Our work is based on the realization of software using Matlab to study the static or dynamic, linear, and rotary electric machines and more particularly the squirrel cage induction motor. These machines are the most common versions of classic electrical machines in every energy system. In this paper, we focus on the implementation of the LEC_RBR software developed in the Electrotechnical Laboratory of Constantine for the determination of the electrical and magnetic quantities in the squirrel cage induction motorL'érosion interne est l'une des causes principales de rupture des ouvrages hydrauliques. Elle peut être développée sous forme de deux phénomènes fondamentaux à savoir le renard hydraulique et la suffusion, ils diffèrent par leurs conditions aux limites géométriques et hydrauliques, le risque de rupture est en conséquence différent. Le premier phénomène est le plus dangereux et le plus rapide, s'il n'est pas immédiatement stoppé, il conduit très rapidement à la rupture. Dans le second, la perméabilité du milieu est lentement modifiée et après une phase de développement ininterrompue, il peut y avoir rupture. En se basant sur une loi d'écoulement type Darcy et une loi d'érosion de Papamichos et enfin une loi d'évolution de la viscosité de fluide (relation d'Einstein), nous proposons une première approche de modélisation de la suffusion, par la mise en évidence de l'évolution dans le temps de la porosité moyenne de la matrice solide du milieu poreux, de la concentration du fluide en particules érodées, ainsi que l'évolution de la masse des particules érodées, tout en mettant en évidence l'influence de la variation des paramètres mécaniques et hydrauliques du sol sur cette évolution tel que le coefficient d'érosion, la porosité maximale ...etc. La résolution numérique du problème est réalisée par la méthode des différences finies. L'échantillon étudié est discrétisé en un ensemble de couches élémentaires. La couche élémentaire est référencée par l'indice j et l'instant par l'exposant i. Pour la discrétisation, on a adopté le schéma explicite décentré. Les résultats de simulation indiquent que le phénomène de suffusion est fortement lié aux paramètres mécaniques et hydrauliques du sol à savoir le coefficient d'érosion λ, la porosité finale Ømax

Survey on QoE/QoS Correlation Models for Video Streaming over Vehicular Ad-hoc Networks

Vehicular Ad-hoc Networks (VANETs) are a new emerging technology which has attracted enormous interest over the last few years. It enables vehicles to communicate with each other and with roadside infrastructures for many applications. One of the promising applications is multimedia services for traffic safety or infotainment. The video service requires a good quality to satisfy the end-user known as the Quality of Experience (QoE). Several models have been suggested in the literature to measure or predict this metric. In this paper, we present an overview of interesting researches, which propose QoE models for video streaming over VANETs. The limits and deficiencies of these models are identified, which shed light on the challenges and real problems to overcome in the future

Hidden Markov models & principal component analysis for multispectral palmprint identification

Automatic personal identification from their physical and behavioral traits, called biometrics technologies, is now needed in many fields such as: surveillance systems, access control systems, physical buildings and many more applications. In this paper, we propose an efficient online personal identification system based on Multi-Spectral Palmprint images (MSP) using Hidden Markov Model (HMM) and Principal Components Analysis (PCA). In this study, the band image {RED, BLUE, GREEN and Nearest-InfraRed (NIR)} is rotated with different orientations then applying the PCA technique to each oriented image, to decorrelate the image columns, and concentrate the information content on the first components of the transformed vectors. Thus, the observation vector is formed by concatenate some components of the transformed vectors for all orientations. Subsequently, we use the HMM for modeling the observation vector of each MSP. Finally, log-likelihood scores are used for MSP matching. Our experimental results show the effectiveness and reliability of the proposed approach, which brings both high identification and accuracy rate

Towards Mitigating Jellyfish Attacks Based on Honesty Metrics in V2X Autonomous Networks

In vehicle-to-everything (V2X) networks, security and safety are inherently difficult tasks due to the distinct characteristics of such networks, such as their highly dynamic topology and frequent connectivity disruptions. Jellyfish attacks are a sort of denial of service attack that are challenging to deal with, since they conform to protocol norms while impairing network performance, particularly in terms of communication overhead and reliability. Numerous existing approaches have developed new techniques with which to identify and prevent these attacks; however, no approach has been capable of facing all three types of Jellyfish attacks, which include reordering attacks, delay variance attacks, and periodic drop attacks. In this work, we design a new protocol that analyzes the behavior of every node in a network and selects the trusted routes for data transmission to their intended destination by calculating different Honesty metrics. The OMNET++ simulator was used to evaluate the overall performance of the proposed protocol. Various evaluation metrics, such as the packet delivery ratio, end-to-end delay, and throughput, are considered and compared with other existing approaches