Abdelhabib Bourouis

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 d...

Queuing theory is the mathematical study of waiting phenomena that allows several performance measures derivation and calculation. Furthermore, queueing systems could be simulated, especially in case of complex models including non-classical concepts. The theory has been applied successfully in diverse fields and the development of a Domain Specific Modeling Language (DSML) for extended queueing systems seems to be a necessity and of great interest. This paper focuses on the cornerstone of this process by providing a minimal but clear and extensible metamodel called EQNM 2 L. Our aim is to induce discussion on and contributions for elaborating a whole mature DSML. The proposed metamodel and the XML-based exchange format are the first step in enhancing interoperability between analytical solvers and simulation tools. Based on the Model Driven Engineering (MDE) approach principles and tools, modeling environments and simulation/analytical code are generated automatically and could be ...

— In this paper we present a new approach for using semantic web technologies in modeling and simulation. In recent years ontologies have been used popularly in many fields to represent and structure their concepts. This work is an attempt to create a specific ontology for the process oriented discrete event simulation domain. The ontology instances represent the model instances. This instance described in XML format and then transformed to another form that is used to generate the simulation code via XSLT rules. The code is generated according to the open source library Japrosim. The objective of this work is to enhance interoperability and automation of the transition from the ontology to the code execution. Keywords-component; Ontology, Semantic Web, modeling and simulation, code generation, interoperability.

For decision makers, the Business Model is crucial for the success of organizations. It reflects manager's assumptions about what customers want, and how an enterprise can best meet those needs and get paid for. Decision support systems can assist in making Business Model design decisions. However, previous work on decision support systems for business models provides no solution for explaining their reasoning for managers. The purpose of this paper is to discuss the development of a new generation of intelligent decision support system that have ability of providing explanations to increase confidence in proposed solutions. The intelligent system by giving some support for the suggested conclusions could be used as learning tool in business schools. The proposed system uses Case-Based Reasoning (CBR) as the resolution methodology, which is an important aspect of artificial intelligence. It is a computational methodology designed to generate new solutions to given problems by an...

Les travaux realises dans ce manuscrit s’inscrivent dans le cadre de l’ingenierie dirigee par les modeles. En partant d’une investigation des possibilites d’utilisation des concept-maps dans les differentes etapes d’un projet de modelisation et de simulation, nous avons developpe un formalisme visuel sous forme de conceptmap pour la modelisation des systemes a evenements discrets. Ce formalisme baptise EQNM2L s’inspire de la theorie des reseaux de files d’attente et s’avere extensible et expressif. Un format d’echange standard base sur XML a ete propose pour favoriser l’interoperabilite entre les outils de simulation et d’analyse. Dans la perspective d’automatiser la generation du code de simulation (ou d’analyse), la transformation de modeles nous a servi de moyen pour obtenir un code Java complet selon la bibliotheque JAPROSIM developpe aussi dans le cadre de ces recherches. La transformation de modeles a ete realisee utilisant XSLT.

Queuing theory is the mathematical study of waiting phenomena that allows several performance measures derivation and calculation. Furthermore, queueing systems could be simulated, especially in case of complex models including non-classical concepts. The theory has been applied successfully in diverse fields and the development of a Domain Specific Modeling Language (DSML) for extended queueing systems seems to be a necessity and of great interest. This paper focuses on the cornerstone of this process by providing a minimal but clear and extensible metamodel called EQNM 2 L. Our aim is to induce discussion on and contributions for elaborating a whole mature DSML. The proposed metamodel and the XML-based exchange format are the first step in enhancing interoperability between analytical solvers and simulation tools. Based on the Model Driven Engineering (MDE) approach principles and tools, modeling environments and simulation/analytical code are generated automatically and could be ...

The aspect-oriented programming paradigm (AOP) as a way of improving the separation of concerns principle has emerged initially at the programming level using strong languages like AspectJ. Currently, it becomes mature to stretch at premature stages of the software development process namely, the Aspect-Oriented Software Development (AOSD) which is a popular topic of software engineering research that leads to more dependable, reusable and maintainable artifacts. In this paper, we propose a UML profile for modeling crosscutting concerns where the separation of concerns is maintained to the level of code and the weaving is done by an AspectJ compiler.

Several routing protocols have been proposed for ad hoc vehicle networks. They affect directly but differently the quality of the transmitted data. In this paper, we introduce a multipath feature to decrease packet loss in greedy perimeter stateless routing protocol (GPSR). Since using only one path during transmission may cause packet loss due to congestion and saturation in this path. Our enhancement is based on sending the same packet over two different paths to maximize its reception probability. This scheme is evaluated in a highway environment using Omnet++, Veins, and SUMO. The results show that the proposed solution overcomes GPSR in packet delivery ratio.

Background: Case-Based Reasoning (CBR) is a problem-solving paradigm that uses knowledge of relevant past experiences (cases) to interpret or solve new problems. CBR systems allow generating explanations easily, as they typically organize and represent knowledge in a way that makes it possible to reason about and thereby generate explanations. An improvement of this paradigm is ontology-based CBR, an approach that combines, in the form of formal ontologies, case-specific knowledge with domain one in order to improve the effectiveness and explanation capability of the system. Intelligent systems make daily activities more easily, efficiently, and represent a real support for sustainable economic development. On the one hand, they improve efficiency, productivity, and quality, and, on the other hand, can reduce costs and cut waste. In this way, intelligent systems facilitate sustainable development, economic growth, societal progress, and improve efficiency. Aim: In this vision, the p...

Video streaming is one of the challenging issues in vehicular ad-hoc networks (VANETs) due to their highly dynamic topology and frequent connectivity disruptions. Recent developments in the routing protocol methods used in VANETs have contributed to improvements in the quality of experience (QoE) of the received video. One of these methods is the selection of the next-hop relay vehicle. In this paper, a QoE-aware geographic protocol for video streaming over VANETs is proposed. The selection process of the next relay vehicle is based on a correlated formula of QoE and quality of service (QoS) factors to enhance the users’ QoE. The simulation results show that the proposed GeoQoE-Vanet outperforms both GPSR and GPSR-2P protocols in providing the best end-user QoE of video streaming service.

Modeling complex systems, including discrete event systems, remains a challenge. The complexity and the size of such systems prevent understanding their models. This article proposes an approach for reducing queuing networks large models into smaller ones. The objective is to reduce the analysis as well as the simulation times in addition to the better understanding of the system under study. The basic idea is to divide the model into a set of smaller, hierarchically organized and more manageable sub-models, which are analyzed in isolation. The key contributions of this work are the substitution of each sub-model by a single M/G/8 station and the automation of the decomposition process using model transformation techniques. The main conclusion is that the reduction approach provides exact results for the global mean number of clients and mean residence time at the whole network.

At a time when complexity becomes a major issue in system modeling, it becomes necessary to simplify, as much as possible, complex systems to be modeled. The inherent complexity of this latter obstructs understanding of their models. In turn, the number of components, interactions between them and the size of the model, increase when complexity increases. As a result, visualization and comprehension become difficult. As well, the analysis or the simulation of large models becomes time consuming tasks. For these reasons, there is a need to reduce the system size, which reduces the number of components and time analysis or simulation. In this field, there is a wide range of methodologies for reducing large models, but they are often specialized according to modeling languages. In this work, we are interested to queueing networks reduction methodologies. This article gives an approach for reducing EQNM2L (Extended Queuing Networks Modeling and Markup Language) large model to a smaller one. The objective is to reduce the analysis time as well as the simulation time of the network. The basic idea is to divide the model into a set of submodels which are analyzed in isolation. In this work, we propose to substitute each submodel by a single M/G/∞ station. The main conclusion of this work is that this adopted rule provides exact results for the mean number of clients at the network and the mean time spent at the whole network. For other parameters, approximated results are obtained.

ABSTRACT Discrete event simulation (DES) projects implement several crosscutting concerns, such as event scheduling, event handling, and keeping track of a simulation's state which tend to produce a tangling and scattering simulation code. This increases the complexity and reduces the maintainability which requires specific separation of concerns (SOC). The aspect oriented programming (AOP) paradigm puts a greater focus on crosscutting concerns than other language paradigms. It provides language mechanisms such as the prominent AspectJ, that explicitly capture crosscutting concerns in a modular way and thus achieving the benefits that results from improved modularity; code that is easier to design, implement, maintain, reuse and evolve. In this paper, we present the most benefits of using the aspect oriented programming paradigm in the simulation modeling field. Besides that, we identify the main crosscutting concerns for a discrete event simulator.

JAPROSIM is a free and open source discrete event simulation (DES) framework implemented in Java programming language for building discrete event simulation models. Separation of concerns (SOC) is one of the basic principles applied in design in order to improve software quality. Aspect oriented programming (AOP) has been proposed as a new technology that claims the application of this principle in the best way, through the modularisation of crosscutting concerns in additional units namely, aspects. In this paper, the main JAPROSIM crosscutting concerns are identified and adequate solutions using the AspectJ language are presented. An empirical evaluation of the Aspect Oriented version of JAPROSIM is performed using the AOPmetrics tool. The results obtained show that the separation of JAPROSIM crosscutting concerns improves its quality attributes as modularity, understandability, maintainability, reusability, and testability.

Mobile Ad hoc networks attract more attention over the years, but the security matter of this type of network makes it hard to achieve all of their advantages. Cryptographic key management is the cornerstone for building any robust network security solution. Identity-based cryptography is a promising solution that resists well the key escrow problem which is suitable for Mobile Ad hoc networks. In this paper, we give an overview of the most important identity-based encryption schemes proposed in the last decade; combined with other techniques to enhance it and provide better results for Mobile Ad hoc networks. Hence, we give a comparative analysis to highlight their advantages and weaknesses. This work gives insights into a recent research to point out its interesting features, take advantages of its strength, ovoid its weaknesses and to lay out the future directions in this area.

This paper is about using xml standard to enhance simulation models exchange, reuse and high level interoperability. We present the concept and demonstrate the utility of the QNML, which is an XML dialect for describing queueing networks. Our work is split into three stages. Firstly, a graphical modelling framework allows users to visually specify their models and generates the equivalent QNML document. In a reciprocal way, graphical models may also be generated from those XML documents. Secondly, XML models are automatically translated into executable simulation models using XSLT. Finally, simulation trace and results are also described in XML to facilitate further processing.

L'un des problèmes majeur de la simulation à événements discrets est la difficulté de détecter le début de la phase d'équilibre. L'inclusion des données de la transitoire initiale dans les résultats de la simulation conduit à des biais statistiques dans les estimations des indices de l'état d'équilibre. Théoriquement, ce problème peut être appréhendé grâce à plusieurs techniques mais dans la pratique peu de simulateur sont doté de mécanismes de détection de la phase d'équilibre. La bibliothèque de simulation à événements discrets Japrosim est l'un des outils qui ne possède pas ce mécanisme de détection de la phase d'équilibre. L'objectif souhaitable est d'intégrer cette bibliothèque avec un mécanisme de détection de la phase d'équilibre.

The problem of realizing the Separation Of Concerns (SOC) principle is at the heart of the software crisis where crosscutting concerns tend to produce a messed simulation systems by decreasing their modularity, and reducing their reuse. Aspect-Oriented Programming paradigm is newly technique introduced for software development. It may co-exist with other methodologies, such as object-oriented, in order to keep the most system interesting properties, such as
reusability and adaptability. In this paper, we present a synthetic study of the most efforts of using the aspect oriented programming paradigm (AOP) in the simulation modeling field. Besides that, we explore the promising perspectives in this research area and our ongoing work towards an Aspect Oriented Simulation Framework (Japrosim).

This paper describes important features of JAPROSIM, a free and open source simulation library implemented in Java programming language. It provides a framework for building discrete event simulation models. The process interaction world view adopted by JAPROSIM is discussed. We present the architecture and major components of the simulation library. In order to ascertain important features of JAPROSIM, examples are given. Further motivations are discussed and suggestions for improving our work are given.

A large research effort has been devoted to enrich mainstream languages as C, C++, Java, Python with simulation capabilities. The most common choice is to provide the additional simulation functionality through a software library. Independently of the architectural level at which they are provided (application, library, language), the simulation capabilities embody a world view for their users. In this paper we present the architecture and major components of an object-oriented simulation library written in Java. The process-
interaction worldview adopted by the library is discussed. A practical example is given in order to ascertain important features of the library. Further motivations  are  discussed  and  suggestions  for improving our work are given.

Japrosim is a discrete event simulation (DES) framework that has been developed for academic and industrial purposes based on object oriented paradigm. It contains several
crosscutting concerns such as animation, steady state detection, keeping track of a simulation’s state and graphical user interface (GUI). These concerns cross its modules and tend to decrease its modularity, understandability, maintainability, reusability, and testability properties. One of the latest offerings of software engineering domain is the aspect-oriented (AO) paradigm, which provides the ability to break free of object-oriented (OO) decomposition, and describe design with a greater degree of separation
of concerns. In this paper, we identify Japrosim crosscutting
concerns and propose practical AO solutions by means of the
de facto AspectJ.

JAPROSIM is a well designed library, free and open source that adopts the popular process-interaction worldview. It is implemented in Java programming language allowing deep access to its powerful features and can serve as a basis for the development of dedicated object-oriented simulation environments. The paper presents architecture and major components of the library. The process-interaction world view adopted by JAPROSIM is discussed. A modeling example is given in order to highlight JAPROSIM capabilities. Important features of JAPROSIM are summarized and suggestions for improving our work are given.

JAPROSIM is a free and open source discrete event simulation  (DES)  framework  implemented  in  Java programming  language  for  building  discrete  event simulation models. Separation of concerns (SOC) is one of the basic principles applied in design in order to improve software quality. Aspect oriented programming (AOP) has been proposed as a new technology that claims the application of this principle in the best way, through the modularisation of crosscutting concerns in additional units namely, aspects. In this paper, the main JAPROSIM crosscutting concerns are identified and adequate solutions using the AspectJ language are presented. An empirical evaluation of the Aspect Oriented version of JAPROSIM is performed using the AOPmetrics tool. The results obtained show that the separation of JAPROSIM crosscutting concerns improves its quality attributes as modularity, understandability,  maintainability,  reusability,  and testability.

The aspect-oriented programming paradigm (AOP) as a way of improving the separation of concerns principle has emerged initially at the programming level using strong languages like AspectJ. Currently, it becomes mature to stretch at premature stages of the software development process namely, the Aspect-Oriented Software Development (AOSD) which is a popular topic of software engineering research that leads to more dependable, reusable and maintainable artifacts. In this paper, we propose a UML profile for modeling crosscutting concerns where the separation of concerns is maintained to the level of code and the weaving is done by an AspectJ compiler.

Aspect-oriented modeling and simulation is a new approach which uses the separation of concerns principle to enhance the quality of models and simulation tools. It adopts the separation of concerns (SOC) principle. Thus, crosscutting concerns such as processes synchronization, steady state detection, and graphical animation could be separated from simulation functional modules. The capture of crosscutting concerns in a modular way is carried out to cope with complexity and to achieve the required engineering quality factors such as robustness, modularity, adaptability, and reusability. This paper provides a summary of aspect-oriented paradigm with its usage in simulation by illustrating the main crosscutting concerns that may infect simulation systems. A practical example is given with the use of the Japrosim discrete event simulation library.

The object-oriented software suffers from code tangling and code scattering problems leading to weak code reusability and difficult application evolution. New approaches supporting an advanced separation of concerns (ASoC) are proposed to overcome this dilemma. These latter provide a more powerful constructs for software decomposition than the object-oriented paradigm and their comparison is increasingly considered as an important issue.
This paper is dedicated to the comparison and the assessment of two samples of ASoC approaches: aspect-oriented programming (AOP) and subject-oriented programming (SOP).

This  paper  describes  important  features  of JAPROSIM, a free and open source simulation library implemented in Java programming language. It provides a framework for building
discrete event simulation models. The process interaction world view adopted by JAPROSIM is discussed. We present the architecture and major components of the simulation library. A pedagogical example is given in order to illustrate how to use JAPROSIM for building discrete event simulation models. Further motivations are discussed and suggestions for improving our work are given.

Discrete event simulation (DES) projects implement several crosscutting concerns, such as event scheduling, event handling, and keeping track of a simulation’s state which tend to produce a tangling and scattering simulation code. This increases the complexity and reduces the maintainability which requires specific separation of concerns (SOC). The aspect oriented programming (AOP) paradigm puts a greater focus on crosscutting concerns than other language paradigms. It provides language mechanisms such as the prominent AspectJ, that explicitly capture crosscutting concerns in a modular way and thus achieving the benefits that results from improved modularity; code that is easier to design, implement, maintain, reuse and evolve. In this paper, we present the most benefits of using the aspect oriented programming paradigm in the simulation modeling field. Besides that, we identify the main crosscutting concerns for a discrete event simulator.