Considerable attention has recently been given to the routing issue in vehicular ad-hoc networks (VANET). Indeed, the repetitive communication failures and high velocity of vehicles reduce the efficacy of routing protocols in VANET. The clustering technique is considered an important solution to overcome these difficulties. In this paper, an efficient clustering approach using an adapted k-means algorithm for VANET has been introduced to enhance network stability in a highway environment. Our approach relies on a clustering scheme that accounts for the network characteristics and the number of connected vehicles. The simulation indicates that the proposed approach is more efficient than similar schemes. The results obtained appear an overall increase in constancy, proven by an increase in cluster head lifetime by 66%, and an improvement in robustness clear in the overall reduction of the end-to-end delay by 46% as well as an increase in throughput by 74%.

Game-Based Learning (GBL) has become extensively used in Technology-Enhanced Learning (TEL) as a substitute for traditional education methods. Moreover, research has been done in this field proves that it’s very interesting for Learning Game (LG) designers to integrate the latest technologies in order to augment GBL efficiency and to reach more learners. On the other hand, context awareness and adaptation are a crucial aspect in mobile game-based learning. It is thus necessary to place at the disposal of the learner player an adaptive mobile game based learning according to the context. However, the contextualisation in the training is not easy to reach. The diversity of mobile technologies and dynam-ics in mobile environments complicate the process of contextualisation. Further-more, migration and implementation of these novel technologies can be very pricey and require more informatics knowledge and time, which can lead to a huge loss. Thus, the main purpose of this article is to present the proposed e-Adventure architecture using the ZeroCouplage multi-platform Framework that was introduced to solve this problem. We code once and the context awareness for mobile game-based learning is automatically generated.

Today, Vehicular Ad-hoc Networks (VANET) have become an interesting research topic for developing Intelligent Transport Systems. In urban environments, vehicles move continuously and at different speeds, which leads to frequent changes in the network topology. The main issue faced in an urban scenario is the performance of routing protocols when delivering data from one vehicle to another. This paper introduces ECRDP, an Efficient Clustering Routing approach using a new clustering algorithm based on Density Peaks Clustering (DPC) and Particle Swarm Optimization (PSO). First, the PSO algorithm is applied to determine the cluster heads, or a new fitness function for finding the best solutions is formulated using the DPC algorithm. Next, clustering is performed based on the reliability of links parameter between vehicles. Then, a maintenance phase is proposed to update the cluster heads and redistribute the vehicles in the clusters. Finally, the effectiveness of the suggested scheme is evaluated by a simulation operated by MATLAB on a real urban scenario. The results achieved show an overall increase in stability, proven by a reduction in change rate by 74%, and an improvement in performance indicated by an increase in intra-cluster throughput by 34% and inter-cluster by 47%, as well as an overall reduction of average delay by 16%.

Several studies have been conducted in the field of Technology Enhanced Learning(TEL) have shown that the adaptation to learner’s learning styles is a task that must be taken into account during the design phase of the educational sequences in order to increase the student’s motivation. Cognitive psychologists have proposed various models of style, which it’s often represented by using multiple dimensions statistically estimated, each model suggests an instrument for measuring an individual’s learning style. Most of them use questionnaires such as (Honey and Mumford (1992), Kolb (1984), Index of Learning Styles (ILS)). This paper shows the results of a study that was addressed to doctoral students. The sample of the population was made up of 300 persons. The purpose of this study is to illustrate the effectiveness of the French version of the Index Learning Styles (ILS) and uses factor analysis for investigation into various dimensions to help students decrease the time spent on this test. The main finding of this paper is: 1) the integration of the French version of the ILS into eAdventure and 2) the generation of an adaptable learning game (LG) and the developement of a new version of the eAdventure authoring tool based on Eadventure Index of Learning Style (E-ILS), capable of fixing learners’ preferences (desires, habits, etc.).

Since Query Expansion (QE) is known for its effectiveness in increasing query relevancy in IR Systems, and LOD are currently used in different domains for various objectives like suggesting, to users, alternative options based on features of their previous searches and interests. We suggest an approach to enhance Information Retrieval (IR) in the medical domain through QE using two Linked Open Data (LOD) bases: DBpedia and Wikidata. We use DBpedia entities within the PubMed abstract, as candidates for expansion, along with their associated labels (“rdfs:label”) in DBpedia base. We evaluate our suggested approach, using MEDLINE collection and Indri search engine. Our expansion approach lead to significant improvements; especially in terms of precision and Mean Average Precision (MAP) compared to related approaches; using only one domain dependant/independent source.

Query Expansion (QE) approaches that involve the reformulation of queries by adding new terms to the initial user query, are intended to ameliorate the vocabulary mismatch between the query keywords and the documents' in Information Retrieval Systems (IRS). One big issue in QE is the selection of the right candidate terms for expansion. For this purpose Linked Data can be used, as a valuable resource, for providing additional expansion features such as the values of sub- and super classes of resources. The underlying research question is whether interlinked data and vocabulary items provide features which can be taken into account for query expansion. In this paper, we introduced a new QE approach that aimed at improving IRS by using the well-known distribution based method Bose-Einstein statistics (Bo1) as well as Linked Data from the knowledge base DBpedia using different numbers of expansion terms. We evaluated the effectiveness of each method individually as well as their combinations using two Text REtrieval Conference (TREC) test collections. Our approach has lead to significant improvement in terms of precision, recall, Mean Average Precision (MAP) at rank 10, and normalized Discounted Cumulative Gain (nDCG) at different ranks compared to Pseudo Relevance Feedback (PRF) that we used as a baseline. The results show that the inclusion of semantic annotations clearly improves the retrieval performance over the baseline method.

Vehicular Ad-hoc Networks (VANET) offer several user applications for passengers and drivers, as well as security and internet access applications. To ensure efficient data transmission between vehicles, a reliable routing protocol is considered a significant challenge. This paper suggests a new clustering-based routing protocol combining a modified K-Means algorithm with Continuous Hopfield Network and Maximum Stable Set Problem (KMRP) for VANET. In this way, the basic input parameters of the K-Means algorithm, such as the number of clusters and the initial cluster heads, will not be selected randomly, but using Maximum Stable Set Problem and Continuous Hopfield Network. Then the assignment of vehicles to clusters will be carried out according to Link Reliability Model as a metric that replaces the distance parameter in the K-Means algorithm. Finally, the cluster head is selected by weight function according to the amount of free buffer space, the speed, and the node degree. The simulation results have proved that the designed protocol performs better in a highway vehicular environment, compared to the most recent schemes designed for the same objective. In fact, KMRP reduces traffic congestion, and thus provides a significant increase in Throughput. In addition, KMRP decreases the transmission delay and guarantees the stability of the clusters in high density and mobility, which acts better in terms of the Packet Delivery Ratio.

Information Retrieval (IR) in the medical domain is considered as a challenging task for many reasons. Short health queries tend to lack information on user's intent, and the target corpus may not have sufficient information for Relevance Feedbacks. And even, if the user obtains relevant documents to his/her queries, it is difficult for him/her to understand the technical terms. In contrast, in this paper, we propose an approach for health queries reformulation based on graph matching between two external linked data sources: DBpedia and Unified Medical Language System (UMLS). DBpedia has a broad coverage of topics and less noise compared to Wikipedia articles, and UMLS is specific to the medical domain. We also introduced the degree centrality to measure the graph connectivity and to select the most efficient candidate terms for query expansion. Experimental results on MEDLINE collection using Okapi BM25 as a retrieval model showed that our approach outperformed related methods, and the two sources achieved very good retrieval results. They helped in the diversification of the retrieved documents and the improvement of the recall.

The purpose of this paper is to suggest an approach for increasing the convergence speed of Halley’s method to solve a non-linear equation. This approach is based on the second order Taylor polynomial and on Halley’s formula. By applying it a certain number of times, we obtain a new family of methods. The originality of this family is manifested in the fact that all its sequences are generated from one exceptional formula that depends on a natural integer parameter p . In addition, under certain conditions, the convergence speed of its sequences increases with p . The convergence analysis shows that the order of convergence of all proposed methods is three. A study on their global convergence is carried out. To illustrate the performance of this family, several numerical comparisons are made with other third and higher order methods.

In this study a validated antenna into simulation and through measurement has been described and analyzed. The coplanar waveguide (CPW) technique has been chosen to feed the radiating patch while the two ground planes have been partially designed in the top side of the substrate. The fractal geometry, applied to the circular radiator, has been obtained by merging the circular and rectangular shapes. The fiberglass FR-4, with a single side of 35μm copper thickness, has been used to achieve the antenna material with a permittivity of 4.4, a thickness of 1.6 mm, a loss tangent of 0.025 and an overall dimension of 34x43 mm 2 . The proposed CPW fractal antenna has been configured to operate in the frequency range 3.1-10.6 GHz published by the federal communications commission (FCC) as an ultra-wide band (UWB). To calculate the return loss, the gain, the current density and the radiation pattern of the simulated antenna, two electromagnetic solvers have been involved which are the CST microwave studio and ADS. The series of measurement have been performed by using the network analyzer and the anechoic chamber in order to confirm the computed antenna.

In this work, new design and simulation of a microstrip power limiter based on Schottky diode is presented. The proposed circuit is a zero bias power limiter built by associating a transmission line in parallel to a four Schottky rectifier bridge circuit. The first circuit using a single stage rectifier is analyzed and simulated. To improve this single stage, a second and final limiter is designed with two stages rectifier. Simulation results for the final circuit show an ideal limiter behavior and good performance of limiting rate up to 20dB for a threshold input power varying from 5 dBm to 30 dBm. While insertion loss remains low at small signal.

The high mobility and frequent changes in the network topology remain a great divergence between Vehicular Ad-hoc Network (VANET) and Mobile Ad-hoc Network (MANET). This makes existing routing protocols for MANET imperfect for a VANET environment. In order to ensure good data transmission between vehicles, it is mandatory to improve these protocols to this new environment. Ad-hoc On-demand Distance Vector (AODV) is one of the most proposed reactive protocols in the literature for MANET, but its direct application in VANET returns poor performance results. In this paper, we propose an Efficient Routing Protocol using an improved Distance-Based Broadcasting and Fuzzy Logic System (ERPFL), which is an extension of the AODV routing protocol. In the first, the proposed scheme uses an improved Distance-Based Broadcasting method in route discovery process. Each vehicle selects the most suitable neighbours to send a route request, using different mobility parameters such as distance, velocity and direction. Then, the destination vehicle selects the best route from the most reliable routes received, using the Fuzzy Logic System. Link Expiration Time and Link Reliability Model are considered input metrics for this system. The simulation results show that ERPFL saves network bandwidth resources which contributes to a higher data transmission ratio. In addition, our proposed protocol efficiently distributes data packets, decreases the hop count and reduces network routing time.

In this paper, we propose a routing protocol using an adaptive K-Harmonic Means (RPKHM) in order to improve the lifetime of links between vehicles and to increase the stability of the vehicular network. First, the number and initial positions of the centroids are determined using a mathematical model that takes into account the total number of vehicles and the network topology. Whereas, the clustering is done using a similarity value based on the Euclidean distance, the difference in speed and direction of the vehicles. Finally, the maintenance of the clusters and the selection of new cluster heads are based on a cost function, which takes into account the total size of the free buffer and expected transmission count (ETX). The simulation results show the efficiency of the proposed scheme in terms of Packet Delivery Ratio, average End-to-End Delay, and Throughput.

Wireless power transmission is an alternative energy solution to supply power to the electrical and electronics equipment without wired connection. In this paper we present an antenna array design which is the crucial part in a Rectenna (rectifier + antenna) system. The developed design consists of a new 3×3 antenna array having an operating frequency of 2.45 GHz with inclined slots at the center of each antenna element to improve the circular polarization and V-shaped slots to enhance the bandwidth around the operating frequency. The proposed design provides a high gain of 9.14dBi and overall size of 26.18×11.86 cm 2 .Simulation and measurement results are in good agreement which make this antenna very suitable for WPT applications.

This article presents a new miniature microstrip antenna in the ISM "Industrial Scientific and Medical" band, at 2.45 GHz. This microstrip antenna is designed for RFID reader system, by exploiting the fractal technique and the CPW fed; this antenna is printed on FR4 substrate with dielectric constant of 4.4. The validated antenna has a good matching input impedance range from 2.27 GHz to 2.68 GHz with a stable radiation pattern, a gain of 2.2 dBi, and a directivity of 1.91 dB. The total area of the final circuit is 21.22 x 32.05 mm2. A prototype of the proposed antenna has been fabricated and measured.

In this paper, we present a new design of a microwave microstrip power limiter validated by simulation into ADS (Advanced Design Software) software. The power limiter is built on a FR4 microstrip using a Zero Biais Schottky diodes from Avago technologies. The optimization and validation of this devices follows two steps. Firstly, a basic circuit formed of two parallel lines which exhibit an electrical line difference of half wave. The final circuit is formed by cascading two basic circuits. This circuit exhibits ideal power limiter characteristics. The power limiter threshold is registered at 0dBm. The power range is validated from -20dBm to 30dBm.

This chapter presents the design of some miniature antenna for RFID application, in the ISM (industrial, scientific, and medical) band at 915 MHz and 2.45 GHz, by using two techniques. The first technique is the use of slots inserted into the microstrip antenna, and the second technique is the use of the fractal structure. In the end, both techniques are used together in one structure to get the benefit of each technique at the same time. These antennas are designed for RFID system. They can be used in a variety of fields such as access control, transport, banks, health, and logistics. One major consideration for handheld and portable RFID system applications is the compact size. Therefore, the design of miniature RFID antennas is important, and the microstrip antenna is a good choice because they are known to be low-profile, low weight, easy to make, and mechanically robust.

The wireless system of communication has recently known a considerable evolution, which has led to the appearance of a new type of networks called Vehicular Ad hoc Networks (VANET). This innovative approach is crucial for enhancing the quality of the driving experience as a whole: the safety of the drivers, traffic management and the entertainment of the passengers. Thus, the selection of an appropriate routing protocol is necessary to support high mobility, rapid changing topology and capacity of mobility prediction. In this paper, we evaluate the performance of a set of well-known routing protocols used in VANET, namely AODV, DSR and DSDV in terms of Packet Delivery Ratio (PDR), Throughput, and Normalized Routing Load (NRL), in order to find out the suitable routing protocol for high density traffic area such as Casablanca. In this paper, the real map of Casablanca is edited by Open Street Map (OSM), and the “Simulation of Urban Mobility” (SUMO) tool is used to create the mobility model, while the traffic model generation and the simulations are carried out using Network Simulator 2 (NS2).

In this article, a novel limiters power is designed and validated by ADS software. The new limiter is based on a mictrostrip circuit and uses MSFET transistors and Schottky diode as actives components. This Power Limiter have been optimized in two steeps: the first circuit is composed of one stage. Simulation of this circuit presents some limitation in termes of limitation rate. To improve this performance, a new circuit composed of two stages is simulated and optimized. The final circuit exhibits 25 dB of limitation rate while insertion loss is -1 dB with a threshold input power level of 0 dBm until a maximum input power level of 30 dBm.

One of the well known techniques that are used to increase the relevancy of user queries is query reformulation through the expansion of queries. Also, Linked data are being used in various fields and available for different domains. This paper aimed at improving Information Retrieval results using