Proceedings of the Mediterranean Conference on Information & Communication Technologies 2015

This work comes with a novel study on the design of a CPW-Fed multi band planar antenna. This structure can be integrated easily with passive and active elements. The antenna validated is suitable for GPS, UMTS and WiMAX bands. Its entire area is 70.4 × 45 mm2 and is printed on an FR-4 substrate. Simulation results show that the antenna has a good input impedance bandwidths for S11 ≤ −10 dB, covering the GPS, UMTS and WiMAX bands. This antenna is optimized, miniaturized and simulated by using ADS “Advanced Design System”, with a comparison with another software CST Microwave Studio.

The probe is one of the major components building an indoor system for antenna near field measurement. This device allows to collect the distribution of the field radiated by the antenna under test (AUT), and to transform it into available voltage at its output. Thus, because of the response of the probe to other components of the field radiated by the AUT, to the influence of the geometric parameters of this one and to the problems related to the measuring surface. An unwanted error appear between the voltage and the field, and a step of post-processing is therefore necessary to correct this one. In this paper we address the problem for the correction by the technique of the deconvolution, a probe based on an Open Ended Rectangular WaveGuide (OERWG) is used to validate this approach. Thus, the spatial response of the probe is calculated in module and validated by three AUT, an open ridges rectangular waveguide, an open circular waveguide and a dipole antenna. The results obtained show that the calculated reference field and the reconstructed one are confused for the three antennas under test.

Beam-steering antennas are the ideal solution for a variety of system applications, it is most commonly achieved through using phased arrays, where phase shifters are used to control the relative of the main-beam. In this paper, a low-cost directive beam-steering phased array (DBS-PA) antenna using switched line phase shifters is demonstrated. The proposed DBS-PA antenna has four micro-strip patch antennas, three power dividers and four phase shifters printed on the same Rogers RT-Durroid substrate with a dielectric constant of 2.2 with dimensions of 8 × 3.5 cm. The phased array antenna has a directivity of 11.92 dBi and the main beam direction can be switched between the angles of ±25° with a 3 dB beam-width of 23°. All design and simulations have been carried out using Ansoft HFSS software tool. The frequency considered for the operation is 10 GHz.

This paper presents a V-band buffer amplifier based on 0.15 µm pHEMT from UMS foundry for WPAN applications. This amplifier will be used as a part of a frequency quadrupler in the millimeter wave band at 60 GHz. The amplifier circuit can deliver a gain up to 13 dB at 60 GHz with a low noise figure of 2.4 dB. An input return loss of 18 dB and an output return loss of 10 dB are also achieved by this amplifier. The input P1 dB and IP3 are 0.3 and 27 dBm respectively.

This paper presents the simulation of a UHF RFID (Radio Frequency Identification) system for passive tags, using Advanced Design System software from Agilent Company. Temporal measurements based on a commercial RFID reader are achieved which permit to analyze and to validate the principles of communication between the reader and the tag. Also a test bench is developed to evaluate the effects of high temperature on the reliability of passive UHF RFID tags. The obtained test results show that the thermal storage has a marked effect on the performances of the RFID tags.

Today the security of RFID systems is a very important issue especially for low cost RFID tags. Then, it is difficult for several researchers to adopt a strong encryption algorithm due to the extremely limited computational, storage and communication abilities of the tag. So, the priority in RFID systems is to ensure the integrity, confidentiality and authentication of messages using different algorithms (such as encryption and hashing algorithm). In this paper, we propose a lightweight symmetric key encryption approach that includes integrity as part of the encryption process in order to meet the resource limitations of low cost RFID tags. Furthermore we do not need to use separate hash functions to verify message integrity, thus leading to increase the computational efficiency of the system.

The paper describes a complex design of monitoring system handling created by the use of microcomputer Raspberry PI and LF RFID technology for the needs of monitoring and exploring the behavior of small terrestrial mammals and of selected species of birds. Similar systems already exist, but they are demanding and financially not affordable. To create such a system, low-cost products have been used which are easily modifiable, modular and expandable by measuring other activities. The paper concentrates on RFID/PIT technology. PIT tags are a useful tool to identify and follow individuals within a large population to monitor movement and behavior. Tags transmit a unique identifying number that can be read at a short distance that depends on the tag size and antenna design. Passive RFID tags are inductively charged by the reader and do not have a battery. Tags can remain operational for decades.

60 GHz frequency band is candidate for future broadband wireless networks for the last mile because of high available of unlicensed bandwidth worldwide. However, 60 GHz frequency band has limited coverage due to the high free-space losses and the waves do not penetrate the walls. Radio over Fiber (RoF) technology combining both, the high capacity of optical communication and the flexibility of wireless access, can help in extending 60 GHz radio coverage in indoor environment. This paper presents a study of RoF link employing IEEE 802.15.3c Physical Layer (PHY) for 60 GHz frequency band. A simulation of 802.15.3c High-speed interface (HSI) mode in radio over fiber system using the co-simulation technique between OptiSystem and Simulink have been realized. Finally, a BER performance of IEEE 802.15.3c HSI mode in Radio over Fiber system versus the Multi-mode Fiber (MMF) length have been calculated.

In this paper, we evaluate a downlink Multi-User Multiple-Input Multiple-Output (MU-MIMO) scenario, in which a 802.11ac access point with multiple antennas (up to 10) is transmitting to two receivers, each one with two antennas. Block diagonalization (BD) method is investigated under the Equivalent Isotropic Radiated Power (EIRP) constraint. This study shows that scaling the transmitted power according to the EIRP constraint can improve the multi-user (MU) sum capacity to single-user (SU) capacity ratio compared to the gain achieved under the transmitted power constraint.

This paper investigates the use of particle swarm optimization (PSO) for joint channel maximization and estimation in large-scale multiuser multiple-input multiple-output (LS-MU-MIMO) cognitive networks with multiple primary users (PUs) and secondary users (SUs) sharing the same spectrum. The PSO algorithm in this paper is applied at two levels; the mobile station (MS) and the base station (BS). At the MS, PSO is used to seek iteratively the transmit beamforming weights that maximize the uplink MIMO channel capacity for each cognitive user, while controlling the interference levels to PUs without involving any gradient search. At the BS, PSO is used for channel estimation without involving any matrix inversion. The performance of the PSO-based capacity-aware (PSO-CA) cognitive system is compared to the one based on the gradient search scheme (GS-CA) and the results show that PSO-CA requires considerably less computational complexity while achieving essentially the same level of performance as the GS-CA.

Detecting moving objects in sequences is an essential step for video analysis. Among all the features which can be extracted from videos, we propose to use Space-Time Interest Points (STIP). STIP are particularly interesting because they are simple and robust low-level features providing an efficient characterization of moving objects within videos. In general, Space-Time Interest Points are based on luminance, and color has been largely ignored. However, the use of color increases the distinctiveness of Space-Time Interest Points. This paper mainly contributes to the Color Space-Time Interest Points (CSTIP) extraction and detection. To increase the robustness of CSTIP features extraction, we suggest a pre-processing step which is based on a Partial Differential Equation (PDE) and can decompose the input images into a color structure and texture components. Experimental results are obtained from very different types of videos, namely sport videos and animation movies.

In a dispersive medium, GPR signal is classified as a nonstationary signal, and which is widely attenuated, as so, some reflected echoes become none visible neither in the time or the frequency representation of the signal. In fact, we are aimed to calculate the travel time inside a cavity, i.e. the time between two transition that are highly attenuated, in order to identify the nature of the dielectric inside this cavity, which become impossible due to the attenuation phenomena. In this outlook, we proposed to analysis this signal using a time-frequency representation. The continuous wavelet transform is the alternative approach to the Fourier transform due to the fact that the spectrogram is limited in the resolution by the width of the window. Besides the Stockwell transform, in addition to the Hilbert Huang transform are widely used for the analyzed of the electrical, biomedical (ECGs), GPR signals, and seismic sections.

This paper presents a new scale and orientation adaptive object tracking system using Kalman filter in a video sequence. This object tracking is an important task in many vision applications. The main steps in video analysis are two: detection of interesting moving objects and tracking of such objects from frame to frame. We use an efficient local search scheme (based on expected likelihood kernel) to find the image region with a histogram most similar to the histogram of the tracked object. In this paper, we address the problem of scale adaptation. The proposed approach tracker with scale selection is compared with recent state-of-the-art algorithms. Experimental results have been presented to show the effectiveness of our proposed system.

In this paper, we address the lexicon insufficient problem used in the automatic spell checker. In order to solve that deficiency, we developed an approach that aims to correct the derived words, considering that the most Arabic words are derived ones by adjusting the Levenshtein algorithm to our need. This method is based on a corpus constituted of surface patterns and roots characterized by a scaled down size compared to conventional approaches The proposed method reduced the execution time while maintaining the highest correction rate.

This paper presents a new audio watermarking system based on multi-carrier modulation. The proposed system improves the performances of spread spectrum modulations widely used in the existing state of the art watermarking systems. The embedded data is transmitted in the phase of the modulated signal and the amplitude of the carrier signal is computed according to the inaudibility constraint. The new system allows an embedding data rate equivalent to spread spectrum ones with almost no loss of data transparency and with an acceptable detection reliability.

Orthogonal Matching Pursuit (OMP) is one of the most used image reconstruction algorithm in compressed sensing technique (CS). This algorithm can be divided into two main stages: optimization problem and least square problem (LSP). The most complex and time consuming step of OMP is the LSP resolution. QR decomposition is one of the most used techniques to solve the LSP in a reduced processing time. In this paper, an efficient and optimized implementation of QR decomposition on TMS320C6678 floating point DSP is introduced. A parallel Givens algorithm is designed to make better use of the 2-way set associative cache. A special data arrangement was adopted to avoid cache misses and allow the use of some intrinsic functions. Our implementation reduces significantly the processing time; it is 6.7 times faster than the state of the art implementations. We have achieved a 1-core performance of 1.51 GFLOPS with speedups of up to x20 compared to Standard Givens Rotations (GR) algorithm.

Nowadays, with the rapid advancement of internet and the development of digital contents the enormous use of digital data such as multimedia services on the web become a fact. As still images, videos and other works are available in digital form, the ease with each perfect copy can be made may lead large scale unauthorized copying. In this paper a new approach for still image watermarking using least significant bits LSB technique is presented. The proposed algorithm satisfies the invisibility of the embedded colored JPEG image into the cover data under normal viewing conditions. The experimental results based on Matlab simulation by testing Mean square error (MSE), Peak signal to noise Ratio (PSNR) and Normalized Correlation (NC) show that the quality of the watermarked image of our system is higher.

This paper proposes an eye detection method based on neural networks, skin color and eye template. First a multilayer perceptron neural network (MLP) using the retro propagation function with Gabor filter feature is used to detect faces in images. Next a method based on skin color and eyes template used to locate the eyes in detected faces. The results obtained are satisfactory in terms of quality and speed of detection.

In this paper, we present a hard-decision decoding algorithm using Simulated Annealing (SA) technique. The main idea is to find the optimal solution of the transmitted codeword by a process hopping between two different tasks. The simulations, applied on some binary linear block codes over the AWGN channel, show that the Simulated Annealing decoder has the same performance as the Berlekamp-Massey Algorithm (BM). Furthermore SA Decoder is more efficient compared to other Decoder based on Genetic algorithms in terms of performance and run time.

The personal radiofrequency dosimeters are increasingly used for the workers exposure estimation to the electromagnetic radiations in terms of reference level of the fields. The presence of the human body at the vicinity of dosimeter compromises its measurement accuracy. In this paper, the study of interaction between personal radiofrequency dosimeter and human body is presented. First, we deal with the error introduced by the presence of the body and an approach to reduce this impact by adding elements in the dosimeter structure. Indeed, by introducing a metal ground plane and optimizing the height of antenna-ground plane, we can estimate at 10 % close the level of incidental field, that is to say a considerable reduction impact of the body on the dosimeter. We also study the stability of the intrinsic characteristics of the dosimeter (isotropy and front to back ratio). Different simulations were performed in the GSM 900 band with the finite integration technique. In the context of the design of worn-body radiofrequency dosimeters it’s very useful to master these interaction results.

In this paper, we investigate through a theoretical model the effect of duty cycle on reflectivity and bandwidth of optical filters such as Bragg filters. Our work is dedicated to the effect of duty cycle (r) and form factor (Z) on reflectivity, bandwidth and coupling coefficient evolution for different values of the corrugation depth l. The theoretical results are verified by experimental measurements realized on LiNbO₃:Ti.

In this paper, we investigate positioning on the mobile market of a Mobile Virtual Network operator (MVNO). We consider a market segmentation based on brand appeal, taking into account a segment of customers that are attached to the brand of the traditional operator and another segment where customers are less sensitive to the brand appeal of the operator. We consider three cases depending on the presence of the Mobile Network operator (MNO) on each segment and look for assumptions allowing a global Nash equilibrium.

This paper proposes a new semi-analytical method for estimating the error probability for any digital communication system. We show that the problem of the error probability estimation is equivalent to estimating the conditional probability density function (pdfs) of soft receiver outputs. The proposed method uses Fast Fourier transform inversion for predicting the pdf. Furthermore, we applied Bootstrap criterion for selecting the optimum smoothing parameter which makes this method more accurate. Simulation results have shown that the obtained error probability with the new approach is close to that measured by Monte-Carlo simulation method.

The importance of intelligent network (IN) obliges each organism to secure continuously and efficient manner all equipment and data flowing in the network. This document proposes recommendations for telecommunications companies to improve the security level of its Intelligent Networks. These recommendations are justified by tests made by appropriate tools and implemented in an application in order to manage user’s traceability. Therefore, the authors develop a traceability management solution to fight against inappropriate changes in network equipment and monitored.

This paper proposes a new structural method of features extraction for handwritten, printed and isolated numeral recognition based on Freeman code method. It consists of extending the Freeman directions to 24-connectivity instead of 8-connectivity. This new technique shows its performances for the recognition in comparison with other techniques such as the classic Freeman code, the profile projection and the zoning. Numeral recognition is carried out in this work through k nearest neighbors. Results of simulations show that the proposed technique has obtained better results.

Satellite image segmentation is a principal task in many applications of remote sensing such as natural disaster monitoring and residential area detection…These applications collect a number of features of an image and according to different features of an object will detect the object from the image. This type of image (satellite image) is rich and various in content, the most of methods retrieve the textural features from various methods but they do not produce an exact descriptor features from the image. So there is a requirement of an effective and efficient method for features extraction from the image, some approaches are based on various features derived directly from the content of the image. This paper presents a new approach for satellite image segmentation which automatically segments image using a supervised learning algorithm into urban and non-urban area. The entire image is divided into blocks where fixed size sub-image blocks are adopted as sub-units. We have proposed a fusion of statistical features including global features based on the common moment of RGB image and local features computed by using the probability distribution of the phase congruency computed on each block. The results are provided and demonstrate the good detection of urban area with high accuracy and very fast speed.

Flood risk management, since long based on the hazard control, is increasingly orientated towards an attempt to reduce the vulnerability of territories. In fact, the dangers of flood risk on the territory of Casablanca have been the subject of numerous analyzes, whereas studies on the vulnerability of Morocco’s first economic city are very rare. This work aims to contribute to the development of methods for assessing the vulnerability of the urbanized watershed area of Oued Bouskoura facing the overflow of the latter in case of storm floods. The methodology of this study is the use of a geographic information system coupled with the hierarchical multi-criteria analysis developed by T. Saaty (Saaty 1980) for the identification and quantification of urban elements lying in the natural course of Oued Bouskoura and are at risk of flooding.

Discrete Krawtchouk moments are powerful tools in the field of image processing application and pattern recognition. In this paper we propose an efficient method based on matrix multiplication and symmetry property to compute 3D Krawtchouk moments. This new method is used to reduce the complexity and computational time for 3D object reconstruction. The validity of the proposed algorithm is proved by simulated experiments using volumetric image.

In this work, we propose a new local pattern for face recognition, named Local Gradient Probabilistic Pattern (LGPP). It is an extension of Local Gradient Pattern (LGP) that uses a very important result of probability theory; it is the law large numbers. In this direction, the distribution of the gray levels on a face image follows a law of probability, which is the sum of several normal laws. The current pixel will be evaluated by the confidence interval concept. The suggested model is merged with the most known algorithms of data analysis in the face recognition field, in particular the PCA, the LDA, the 2DPCA and the 2DLDA. The tests carried out on the ORL and YALE databases show the effectiveness of LGPP+2DPCA and LGPP+2DLDA systems. The experimental exactitude is of 96 %.

Many applications in the field of computer graphics are becoming more complex and require more accurate simplification of the surface meshes. This need is due to reasons of rendering speed, the capacity the backup and the transmission speed 3D models over networks. We presented four basic methods for simplifying meshes that are proposed in recent years. The result obtained by the implementation of these methods will be the subject of a comparative study. This study aims to evaluate these methods in terms of preserving the topology and speed.

The Mean Shift algorithm for tracking the location of an object has recently gained considerable interest because of its speediness and efficiency. However, the appearance description using only color features cannot provide enough information when the target and its background have similar colors. In response to this problem, an improved human tracking system based on Mean Shift algorithm is incorporated in this paper. The proposed method combines color-texture features and background information to find the most distinguished features between the target and background for target representation. The experimental results show that the proposed method presents a good compromise between computational cost and accuracy; its performance is compared with recent state-of-the-art algorithm on Benchmark dataset and it achieved excellent results.

More and more people resort to the web for searching and sharing information about their health using search engines and forums. These tools have many drawbacks such as: the lack of concise answers, difficulties of presentation of the complex needs of information…In this paper, we look at a new way of delivering information to the users via coherent conversations. After completing a comparative study on recent question answering (QA) systems, the major motivation is to find a solution to address their weaknesses. The solution that we propose is a QA system which takes into account the context of research and allows interaction with the user to understand its purpose, by using different types of data sources.

The cell formation problem attempts to group machines and part families in dedicated manufacturing cells such that the inter-cell movement of the products are minimized while the machine utilization are maximized. In this paper, a clonal selection algorithm is proposed for solving this problem. This algorithm introduces theories of clonal selection, hypermutation and receptor edit to construct an evolutionary searching mechanism which is used for exploration. A local search mechanism is integrated to exploit local optima. In order to demonstrate the effectiveness of the proposed algorithm, most widely used benchmark problems are solved and the obtained results are compared with different methods collected from the literature. The results demonstrate that the proposed algorithm is a very effective and performs well on all test problems.

Recently, the nature has become a source of inspiration for the creation of many algorithms. A great research effort has been devoted to the development of new metaheuristics, especially nature-inspired one to solve numerous difficult combinatorial problems appearing in various industrial, economic, and scientific domains. The nature-inspired algorithms offer additional advantages over classical algorithms; they seek to find acceptable results within a reasonable time, rather than an ability to guarantee the optimal or sub-optimal solution. The travelling salesman problem (TSP) is an important issue in the class of combinatorial optimization problem and also classified as NP-hard problem and no polynomial time algorithm is known to solve it. Based on three nature-inspired algorithms, this paper proposes a comparative study to solve TSP. The proposed algorithms are evaluated on a set of symmetric benchmark instances from the TSPLIB library.

In this paper a novel compact planar monopole antenna with a T-shaped coupling feed for LTE/GSM/UMTS operation in the mobile phone is presented and studied. The proposed antenna has a simple structure, a planar configuration and can be directly printed on the system circuit board of the mobile phone. The antenna size is 40 × 20 mm2 it consisting of T-shaped driven strip and a coupled radiating structure. In addition two wide bands can be generated by the designed antenna for the LTE/GSM/UMTS operation in the mobile phone. The proposed antenna is validated by using two electromagnetic softwares CST-MWS and Ansoft HFSS. Operating principle of this antenna and details of the various antenna parameters are also studied and discussed in this paper. The simulated results including return loss, radiation patterns and current distributions are presented for the proposed antenna.

In this paper, we present a theoretical analysis of the joint effect of carrier frequency offset (CFO) and high power amplifier (HPA) nonlinear distortion (NLD) on the signal to interference plus noise ratio (SINR) of filter bank multicarrier (FBMC) systems. A promising class of FBMC modulation, called Cosine Modulated Multitone (CMT), is considered and the analytical SINR is derived in the presence of both HPA NLD and CFO. The simulation results have shown a good agreement with the theoretical analysis.

The deployment of the fourth generation of mobile network (4G) is going round the world, but with different speeds. When considering the Mediterranean area a big difference can be observed, where some countries has started the implementation of 4G, while other countries just started the call to bid for spectrum auctions. In this paper, we discuss the different factors pushing the mobile network operators to decide to invest in 4G infrastructure; by highlighting the challenges and the risks. Then, we model the migration procedure from 2G/3G/3G+ towards a mix infrastructure including the 4G and 4G-beyonds. We model the migration problem as a “shortest path problem” in the state-space. This consists in finding the optimal path, with minimal costs, between start state (current network state) and the target-state at the end of the migration time window. Finally, we focus on algorithms to be applied to solve this shortest-path approach of the migration.

Adaptive modulation and coding (AMC) is a technique that allows the adjustment of modulation and coding based on the quality of the transmission link, to achieve a transmission with higher data rate and better spectral efficiency. The purpose of this paper is to study the influence of AMC on the High Speed Interface Physical layer (HSI PHY) mode of the IEEE 802.15.3c standard. For this we have created a Simulink model representing the schema of the IEEE 802.15.3c transmitter/receiver with an algorithm which allows adaptation in terms of modulation and coding of the transmitter according to the link in accordance with a predefined script.

Using Buchmann-Williams protocol and relying on the intractability of the discrete logarithm problem in the class group of an imaginary quadratic field, we introduce a new version of Password Authenticated Connection Establishment protocol. This construction (IQF-PACE) can be proved secure in Bellare Pointcheval Rogaway (BPR) model, and provides a variant of the actually elliptic curve instantiation of the PACE protocol to avoid some side channel attacks, particularly, Fault Analysis Attacks (FAAs).

In this paper we develop an algorithm for decoding low-density parity-check (LDPC) code that improve performance and reduce latency time. This algorithm is called Variable Factor Appearance Probability Min Sum (VFAP-MS) and is inspired from the Variable Factor Appearance Probability Belief Propagation (VFAP-BP) algorithm. The presented algorithm exploit the existence of short cycles in the code and strategy for reweighting check nodes, and is suitable for wireless communications applications. Simulation results show that the VFAP-MS algorithm outperforms the standard MS described in the literature.

The Levels Crossings (place of crossing of a railway by a road) are one of the most important sources of accidents in the railway sector in Morocco. For this reason, the National Office of the Moroccan Railways (ONCF) has launched a program which aims at removing hundreds of Level Crossings because of their dangerousness. This paper presents a comparative study between the belief function theory and the imprecise probabilities so as to evaluate the reliability of the Moroccan Level Crossings system over the time by integrating human factor and components failures data uncertainty.

This paper is concerned with the problem of robust stabilization continuous switched nonlinear systems with two additive time varying delays via Takagi-Sugeno (TS) fuzzy model approach. The stabilization conditions for nominal system are derived using Lyapunov-Krasoviskii functional approach. Sufficient conditions for the existence of fuzzy state feedback gain are formulated by linear matrix inequalities. The stabilization robustness is then investigated. Finally, a numerical example is given to show the less conservatism of the stability criteria and the effectiveness of the designed method.

The modeling of a satellite system and its orientation in space is a difficult and important step to define before controlling its attitude. Many methods have been developed since the first satellite was built. In this paper we propose a comparative study of the most important attitude representation methods adopted in the literature. We point out the advantages and disadvantages of each of these methods before choosing the one that suits our objective. Then we present, the Simulink blocks for Rotation angles method, which will be used in our attitude model. After that, we will present the implementation of this model in a system on chip, following the proposed architecture.

The detection of the fetal QRS complex from one composite signal recorded from the abdominal area is a challenging problem for both the biomedical and signal processing communities. In this work, in contrast to the classical approach using Singular Value Decomposition (SVD) based on the analysis of the singular value ratio, we present a new approach using optimal SVD based on difference spectrum energy to detect the QRS complexes of the fetus cardiac activity, also the Undecimated Wavelet Transform (UWT) was used for noise filtering and to determine peaks locations. The result of the R peaks performance measure is calculated for the two approaches. This method is advantageous since it is based on the analysis of one abdominal signal, and it is validated in both the synthetic and real signals.

This paper presents a comparative study between wavelet and steerable pyramid transform for microcalcification clusters. Using multiresolution analysis, mammogram images are decomposed into different resolution levels, which are sensitive to different frequency bands, it is important to extract the features in all possible orientations to capture most of the distinguishing information for classification. The experimental results suggest that S-P shows a clear improvement in the classification performance when compared to wavelet (DWT). These multiresolution analysis methods were tested with the referents mammography Base data MIAS Experimental results show that the steerable pyramid method provides a better.

Sleep spindles are among the hallmarks observed in the electroencephalogram (EEG) that occur during non-rapid eye movement sleep precisely in stage 2. They are transient waveforms of biological and clinical interest. In this paper, we present a method to detect spindles in raw EEG recordings during sleep. The method consists of processing the signal through an adaptive autoregressive model whose features are represented by the zeroes of the model polynomial rather than the prediction coefficients. Tracing in time of the zeros’ modulus shows sharp transitions indicating statistical changes due to the occurrence of spindles. The results obtained were compared to those reported by other techniques based on traditional EEG visual reading used by neurophysiologists.

Telemedicine applications require exposing medical data over open networks, which leads to illegal exploitations. However, safety and confidentiality are required for medical images, because critical judgment is done on those images. Therefore, we propose in this paper, a medical images multiple watermarking scheme. Considering the high sensitivity of medical images, the watermark is embedded without modifying the original host image. Based on visual cryptography concept, difference expansion technique and dominant blocks extraction, this scheme achieves copyright protection by a robust watermark and image authentication by a fragile watermark. The experimental results show that the proposed method can withstand several image processing attacks, and can easily prove the integrity of the image.

Data Mining aims is to extract maximum of knowledge automatically or semi-automatically from huge databases using interactive exploration tools. In this article, we focus on the exploration of medical data to study the case of analyzed sperm samples according to the criteria of the WHO (World Health Organization) using a powerful analysis tool for exploring the results of classification algorithms, clustering and regression. For this research, 100 volunteers provide a semen sample and they were also asked to complete a validated questionnaire on their lifestyle and health status. Sperm concentration is also linked to socio-demographic and environmental factors.

In this study we propose an extension of the mathematical model developed by Derouich et al. [1] by considering the dynamics of healthy people. Moreover an optimal control approach is proposed in order to reduce the burden of pre-diabetes and diabetes with its complications. Our model shows that the number of pre-diabetics and diabetics with and without complications can be limited by a control and hence the overall burden of diabetes can be reduced. The dynamics of a population of healthy, pre-diabetics and diabetics in presence and absence of complications is studied in a period of 10 years with and without optimal control.

A down-conversion layer placed on the front side of silicon solar cells waveguides has the potential to cute one high-energy photon into two low energy photons. This paper examines the Tb3+/Yb3+ energy transfer efficiency in a 70SiO₂–30HfO₂ glass and glass-ceramics waveguide in order to convert absorbed photons at 488 nm in photons at 980 nm. The evaluation of the transfer efficiency between Tb3+ and Yb3+ is obtained by comparing the luminescence decay of Tb with and without Yb co-doping ions. A transfer efficiency of 25 % obtained with glass-ceramic sample and 6 % with glass sample proving that glass-ceramic can be a viable system to fulfil our requirements.

This paper presents an analysis of the nonlinear dynamics of a current-fed boost converter for PV applications with an MPPT algorithm. First, the model of the converter is derived. Simulation results using this model show that the system can exhibit period doubling bifurcation and subharmonic oscillation when some design parameters are varied. Then, the discrete-time modeling approach and Floquet theory is used to perform a stability analysis of the system periodic orbits, to explain the mechanism of losing their stability and to locate the stability limits in the parameter space. Based on the study, a design of the system free from the undesired subharmonic oscillation can be done. The theoretical results are validated by means of numerical simulations from the circuit-level switched model.

In this work, we present the results concerning the design, implementation and test of a photovoltaic installation with two regulation systems, one is a commercial regulator and the other is designed in this work. This latter optimizes the installation operation by a new approach with improved control blocks: MPPT, charging/discharging process, estimates the state of charge and manages the energy between blocks. The regulation systems experiment during 4 days with weather disturbances shows the robustness of the designed one which improves the battery life: the accuracy and speed on the maximization of the power supplied by panels, precision of the state of charge estimation, improvement of the energy management at the charge/discharge.

This chapter presents a PV system composed by a photovoltaic array connected to a DC-DC boost converter with resistive load in order to extract the maximum power generated by the PV panel. This paper presents a model of photovoltaic (PV) system to investigate the P-V characteristics under varying irradiation and temperature conditions. The proposed photovoltaic model is used for evaluating the techniques of maximum power point tracking (MPPT). For this reason, a comparative study between two control methods for maximum power point tracking (MPPT) algorithms in photovoltaic (PV) systems is investigated and well presented. The two MPPT controllers presented in this work are: The Fuzzy Logic Controller (FLC) and the Sliding Mode Controller (SMC). The MPPT controller based on the fuzzy-logic-algorithm is considered as an intelligent technique and it uses directly the DC-DC converter duty cycle as a control variable and it provides a fast response and good performances against the climatic and load changes. The SMC presents, also a very good response for tracking the maximum power point (MPP) for photovoltaic systems. The input parameters that were considered are the voltage and the current. The duty cycle determined by the MPPT controller is used to generate the optimal MPP under different operating conditions. Simulation results show that both algorithms can effectively perform the MPPT hence improving the efficiency of PV systems and via the comparison it is possible to understand the advantages of every controller.

This paper represents a design and simulation of Rectangular Dielectric Resonator Antenna (RDRA) for base stations operating in the UMTS (Universal Mobile Telecommunications System). The Dielectric resonator is planned to be used as a radiating element, fed by a 50 Ω Microstrip transmission line technique at frequency around 2 GHz. The return loss, input impedance, VSWR and radiation patterns are studied. The simulation results were performed using two numerical methods. The conception was realized using finite integration method (CST microwave studio) and verified by finite element method (HFSS: Ansoft high frequency structure simulator).

The concept of heterogeneous networks has already begun with the 4G that will allow communications using all types of services based on IP, and perform a soft handoff between heterogeneous networks. Decisions for vertical handoff in heterogeneous, affect the QoS of the mobile users, which are also dependent upon the mobility. Consequently the choice of the right radio interfaces, at a given moment when mobile terminal has more than one available wireless or mobile network can be based on various factors beside signal strength. In this paper using the IEEE 802.21 standard, we propose to study the impact of handoff latency in lost packet with various speed of the mobile.

The issue of our paper is to expose an original technique to improve the performance of RFID TAG in terms of its geometric dimensions and radiation pattern. This technique exploits the non uniform transmission lines (NUTLs) features to design the passive antenna element on the RFID TAG. We have yet demonstrated that geometric dimensions are reduced and the radiation pattern of the tag was improved by such use of NUTLs. Optimization of the profiles of the different elements of non uniform Lines achieves the appropriate radiation diagram and improves the radiation intensity, consequently.

We theoretically investigate the classical analogue of electromagnetically induced transparency (EIT) in a plasmonic structure constituted by double side cavities connected symmetrically to a waveguide. The EIT is demonstrated by simply detuning the sizes of the two cavities (i.e., the length difference ΔL, keeping their width w similar). The physical mechanism behind the EIT resonance is unveiled as being caused by the destructive and constructive interference between the confined modes in the two cavities. The former play the role of two coupled radiative oscillators. The proposed structure may have important applications for designing integrated devices such as: narrow-frequency optical filters, novel sensors and high-speed switches.

This paper presents propagation of millimeter wave in order to determine the evolution of signal in outdoor environment, we design a wireless transceiver and we evaluate the performance of the High Speed Interface Physical Layer (HSI PHY) of IEEE 802.15.3c standard for investigate the coverage performance of the 60 GHz WLAN. Co-simulation techniques between heterogeneous environment have been used, Advanced Design System (ADS2011) for radio frequency and Matlab/simulink for baseband signal; we have compared the performance of three modulations schemes (64QAM, 16QAM and QPSK) by measuring the Error Vector Magnitude (EVM).

A wireless mobile sensor network is a group of independent wireless mobile sensor nodes which forms a temporary network without the use of any centralized management or fixed infrastructure. Communication protocols are responsible for maintaining the routes in the network and guarantee reliable communication. On the other hand, appropriately adjusting the sensors transmission power is crucial for reducing network energy consumption. This paper proposes a comparison of routing strategies and the impact of variable transmission power for each mobile sensor node on the performance of these communication techniques for mobile wireless sensor networks with the aim of outlining design considerations of protocols for mobile environments. We analyze the performance of both reactive routing protocols Ad hoc On Demand Distance Vector protocol (AODV), Dynamic Source Routing (DSR) protocol and proactive protocol Destination-Sequenced Distance Vector routing protocol (DSDV) in different scenarios. The selected protocols are compared on the basis of various parameters, which include packet delivery ratio, total packet loss, network lifetime, and control overhead using variable number of nodes and speeds.

Wireless Sensor Network (WSN) is a collection of small electronic nodes capable to sense and collect the information of interest in different application. However, these devices are limited in power supply, that is why energy efficient in a crucial factor of wireless sensor nodes. Many researches were performed in order to minimize the energy consumption in different layers of the network and especially at the Medium Access Control (MAC) layer as it coordinate all the sensor nodes to the share the wireless medium. Therefore, a well-designed MAC protocol can prolong the network life. In our survey, we first outline the sensor network properties that are crucial for the design of MAC layer protocols. Then we have compared a set of MAC techniques in terms of their suitability to be used in WSN emphasizing their strengths and weaknesses. Our goal is to yield a foundation for future MAC protocol design, and to detect important design issues that can allow us to enhance the performance of the wireless sensor network.

In this paper, we analyze the voice communication over Long Term Evolution (LTE) network which is transmitted using a voice over internet protocol (VoIP), as in LTE the core network is purely packet switched, designed for high data throughput. Similarly to legacy circuit-switched network, serving the largest number of users performing simultaneous VoIP calls, and ensuring their satisfaction will be the main objective for LTE operators willing to introduce voice over LTE service. To simulate the impact of scheduling strategies in the VoIP capacity, we use the Open Wireless Network Simulator (OpenWNS). With the obtained results, we show the VoIP capacity bottleneck. We also recommend the best strategies to improve the VoIP capacity.