24 research outputs found

    Implementation of CAVENET and its usage for performance evaluation of AODV, OLSR and DYMO protocols in vehicular networks

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    Vehicle Ad-hoc Network (VANET) is a kind of Mobile Ad-hoc Network (MANET) that establishes wireless connection between cars. In VANETs and MANETs, the topology of the network changes very often, therefore implementation of efficient routing protocols is very important problem. In MANETs, the Random Waypoint (RW) model is used as a simulation model for generating node mobility pattern. On the other hand, in VANETs, the mobility patterns of nodes is restricted along the roads, and is affected by the movement of neighbour nodes. In this paper, we present a simulation system for VANET called CAVENET (Cellular Automaton based VEhicular NETwork). In CAVENET, the mobility patterns of nodes are generated by an 1-dimensional cellular automata. We improved CAVENET and implemented some routing protocols. We investigated the performance of the implemented routing protocols by CAVENET. The simulation results have shown that DYMO protocol has better performance than AODV and OLSR protocols.Peer ReviewedPostprint (published version

    An annealing approach to router nodes placement problem in wireless mesh networks

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    Mesh router nodes placement is a central problem to Wireless Mesh Networks (WMNs). An efficient placement of mesh router nodes is indispensable for achieving network performance in terms of both network connectivity and user coverage. Unfortunately the problem is computationally hard to solve to optimality even for small deployment areas and a small number of mesh router nodes. As WMNs are becoming an important networking infrastructure for providing cost-efficient broadband wireless connectivity, researchers are paying attention to the resolution of the mesh router placement problem through heuristic approaches in order to achieve near optimal, yet high quality solutions in reasonable time. In this work we propose and evaluate a Simulated Annealing (SA) approach to placement of mesh router nodes in WMNs. The optimization model uses two maximization objectives, namely, the size of the giant component in the network and user coverage. Both objectives are important to deployment of WMNs; the former is crucial to achieve network connectivity while the later is an indicator of the QoS in WMNs. The SA approach distinguishes for its simplicity yet its policy of neighborhood exploration allows to reach promising areas of the solution space where quality solutions could be found. We have experimentally evaluated the SA algorithm through a benchmark of generated instances, varying from small to large size, and capturing different characteristics of WMNs such as topological placements of mesh clients. The experimental results showed the efficiency of the annealing approach for the placement of mesh router nodes in WMNs.Peer ReviewedPostprint (published version

    Using bi-clustering algorithm for analyzing online users activity in a virtual campus

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    Data mining algorithms have been proved to be useful for the processing of large data sets in order to extract relevant information and knowledge. Such algorithms are also important for analyzing data collected from the users' activity users. One family of such data analysis is that of mining of log files of online applications that register the actions of online users during long periods of time. A relevant objective in this case is to study the behavior of online users and feedback the design processes of online applications to provide better usability and adaption to users' preferences. The context of this work is that of a virtual campus in which thousands of students and tutors carry out the learning and teaching activity using online applications. The information stored in log files of virtual campuses tend to be large, complex and heterogeneous in nature. Hence, their mining requires both efficient and intelligent processing and analysis of user interaction data during long-term learning activities. In this paper, we present a bi-clustering algorithm for processing large log data sets from the online daily activity of students in a real virtual campus. Our approach is useful to extract relevant knowledge about user activity such as navigation patterns, activities performed as well as to study time parameters related to such activities. The extracted information can be useful not only to students and tutors to stimulate and improve their experience when interacting with the system but also to the designers and developers of the virtual campus in order to better support the online teaching and learning.Peer ReviewedPostprint (published version

    Hybrid algorithms for independent batch scheduling in grids

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    Grid computing has emerged as a wide area distributed paradigm for solving large-scale problems in science, engineering, etc. and is known as the family of eScience grid-enabled applications. Computing planning of incoming jobs efficiently with available machines in the grid system is the main requirement for optimised system performance. One version of the problem is that of independent batch scheduling, in which jobs are assumed to be independent and are scheduled in batches aimed at minimising the makespan and flowtime. Given the hardness of the problem, heuristics are used to find high quality solutions for practical purposes of designing efficient grid schedulers. Recently, considerable efforts were spent in implementing and evaluating not only stand-alone heuristics and meta-heuristics, but also their hybridisation into even higher level algorithms. In this paper, we present a study on the performance of two popular algorithms for the problem, namely Genetic Algorithms (GAs) and Tabu Search (TS) and two hybridisations involving them, namely, the GA (TS) and GA-TS, which differ in the way the main control and cooperation among GA and TS are implemented. The hierarchic and simultaneous optimisation modes are considered for the bi-objective scheduling problem. Evaluation is done using different grid scenarios generated by a grid simulator. The computational results showed that the hybrid algorithm outperforms both the GA and TS for the makespan parameter, but not for the flowtime parameter.Peer ReviewedPostprint (author's final draft

    Performance evaluation of a wireless sensor network considering mobile event

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    Presently, there are many research work for sensor networks. In our previous work, we implemented a simulation system for sensor networks. But, we considered that the event node is stationary in the observation field. However, in many applications the event node may move. For example, in an ecology environment the animals can move randomly. In this work, we want to investigate how the sensor network performs in the case when the event node moves. We carried out the simulations for lattice topology and TwoRayGround radio model considering AODV and DSR protocols. We compare the simulation results for two cases: when the event node is mobile and stationary. The simulation results have shown that the routing efficiency for the case of mobile event node is better than the stationary event node using AODV protocol. Also, the goodput for the mobile event node case does not change too much compared with the stationary event case using AODV,but the goodput is not good when the number of nodes is increased.Peer ReviewedPostprint (published version

    Implementation of an e-learning system using P2P, web and sensor technologies

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    This work is motivated by the need to develop decentralized P2P approaches to support learning and teaching activity in virtual universities. In this paper, we present the implementation of the JXTA-based e-learning P2P system. We also show the design and implementation of a SmartBox environment that will be used for stimulating the learners to increase the learning efficiency. The proposed e-learning P2P system is a useful tool for monitoring and controlling learnerspsila activity. We evaluate the proposed system by experimental results and show that proposed system has a good performance. In the future, we aim to use it in real virtual campus environments.Peer ReviewedPostprint (published version

    A Proposed Framework for Combining Smart Environment and Heuristic Diagnostic Teaching Principles in Order to Assess Students’ Abilities in Math and Supporting Them During Learning

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    In this paper, we propose the use of the smart environment based on Internet of Things (IoT), P2P technology and Heuristic Diagnostic Teaching principles for identifying learning abilities in mathematics and creative traits for students that are diagnosed within Autism Spectrum disorder (ASD). Many children with autism are highly interested and motivated by smart devices such as computers and touch screen tablets. These types of assistive technology devices get children with autism to interact, make choices, respond, gain new communication skills and create P2P communication between children, caregivers and therapists. Our proposed system uses JXTA-Overlay platform and SmartBox device to support students during their learning process by getting and maintaining their concentration on a given task. We propose to evaluate children’s ability in math using the Heuristic Diagnostic Teaching principles. Our new system combined with various visual systems, such as objects, photographs, pictures, realistic drawings, line drawings, and written words, can be used with assorted modes of technology, as long as the child can readily comprehend the visual representation. Vocabulary skills, mathematics skills and other life skills can be taught through our proposed system. We propose to use different assessment tools to learn about students’ ability in math

    An annealing approach to router nodes placement problem in wireless mesh networks

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    Mesh router nodes placement is a central problem to Wireless Mesh Networks (WMNs). An efficient placement of mesh router nodes is indispensable for achieving network performance in terms of both network connectivity and user coverage. Unfortunately the problem is computationally hard to solve to optimality even for small deployment areas and a small number of mesh router nodes. As WMNs are becoming an important networking infrastructure for providing cost-efficient broadband wireless connectivity, researchers are paying attention to the resolution of the mesh router placement problem through heuristic approaches in order to achieve near optimal, yet high quality solutions in reasonable time. In this work we propose and evaluate a Simulated Annealing (SA) approach to placement of mesh router nodes in WMNs. The optimization model uses two maximization objectives, namely, the size of the giant component in the network and user coverage. Both objectives are important to deployment of WMNs; the former is crucial to achieve network connectivity while the later is an indicator of the QoS in WMNs. The SA approach distinguishes for its simplicity yet its policy of neighborhood exploration allows to reach promising areas of the solution space where quality solutions could be found. We have experimentally evaluated the SA algorithm through a benchmark of generated instances, varying from small to large size, and capturing different characteristics of WMNs such as topological placements of mesh clients. The experimental results showed the efficiency of the annealing approach for the placement of mesh router nodes in WMNs.Peer Reviewe

    An IoT-Based System for Supporting Children with Autism Spectrum Disorder

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    In this paper, we implement and evaluate the performance of a new system based on Internet of Things (IoT) and P2P technology for supporting learning and improving the quality of life for children with Autism Spectrum Disorder (ASD). Many children with autism are highly interested and motivated by smart devices such as computers and touch screen tablets. These types of assistive technology devices get children with autism to interact, make choices, respond, and tell parents what they are interested, need, think, and maybe even feel. Our proposed system uses JXTA-Overlay platform and Smart Box device to monitor the children and create P2P communication between children, caregivers and therapists. Various visual systems, such as objects, photographs, realistic drawings, line drawings, and written words, can be used with assorted modes of technology, as long as the child can readily comprehend the visual representation. Vocabulary skills, mathematics skills and other life skills can be taught through our proposed system. We evaluated the effect of our system during study sessions of children diagnosed with ASD. The experimental results show that our system teaches new skills to children with ASD and the Smart Box increases the concentration of children during studying
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