Summary This article analyzes the performance of vertical handover between UMTS and WiMAX network... more Summary This article analyzes the performance of vertical handover between UMTS and WiMAX networks by defining development architecture for supporting mobility between these two technologies. First, architectures and principles of operation of networks UMTS and WiMAX are detailed and compared. Then the main protocols of mobility are considered as support of handover between UMTS and WiMAX (802.16). Finally, simulation architecture is presented followed by performance analysis modelled by the simulator NS2 in the context of connection-oriented communication.
To examine the long-term causality between Cardiorespiratory Electromyography Galvanic signals fo... more To examine the long-term causality between Cardiorespiratory Electromyography Galvanic signals for 17 drivers taken from Stress Recognition in Automobile Drivers database. Methods: Two statistical methods, co-integration to reveal an eventual existence of a long-term relationship between ECG (Electrocardiograph), EMG (electromyography), GSR (galvanic skin resistance), heart rate (HR) and respiration, well as the Application of the model of Granger causality. Results: ECG shows certain dependence to EMG, GSR, heart rate and respiration. The results for ECG dependent suggest that an increase of 1% in EMG, FOOTGSR, HAND GSR, HR and RESPIRATION implies a variation of ECG which take a value respectively of 0.016248%, 0.007241%, 0.028366%, 0.000511% and 0.000110% in the within dimension based on the FMOLS (Fully Modified Ordinary Least Squares). With same way, the result for ECG suggest that an increase of 1% in EMG, FOOT GSR, HAND GSR, HR and RESPIRATION implies a variation of ECG which take a value respectively, of 0.065684%, 0.014534%, 0.032800%, 0.000304%, 0.005986% in the between dimension based on the same method. The results of panel Granger causality show a bi-directional relationship between ECG and FOOT GSR, HAND GSR and respiration signals, it must be noted as a unidirectional causality from EMG to ECG. Conclusion: This study shows the long-term interaction between the bio signals, and reveal how the understanding of these interactions can help the doctors to understand the risks that may exist between these interactions. The main advantage of a multidimensional and multivariate model is to solve a multitude of problems that prevent doctors to treat the patients better and is not the case for studies in two dimensions.
In this paper we investigate the problem of modeling multi-resident activities. Specifically, we ... more In this paper we investigate the problem of modeling multi-resident activities. Specifically, we explore different approaches based on Hidden Markov Models (HMMs) to deal with parallel activities and cooperative activities. We propose an HMM-based method, called CL-HMM, where activity labels as well as observation labels of different residents are combined to generate the corresponding sequence of activities as well as the corresponding sequence of observations on which a conventional HMM is applied. We also propose a Linked HMM (LHMM) in which activities of all residents are linked at each time step. We compare these two models to baseline models which are Coupled HMM (CHMM) and Parallel HMM (PHMM). The experimental results show that the proposed models outperform CHMM and PHMM when tested on parallel and cooperative activities.
This paper refers to the generation and analysis of data sequences called De Bruijn quaternary se... more This paper refers to the generation and analysis of data sequences called De Bruijn quaternary sequences for modeling of quaternary modulation formats w itch show very interesting properties. In particular, we will focus on the spectrum, autocorrelation function ...
Recently, has emerged a n ew technology, substrate integrated waveguide (SIW) [1] [2], it has bee... more Recently, has emerged a n ew technology, substrate integrated waveguide (SIW) [1] [2], it has been applied successfully to the conception of planar compact components for the microwave and millimeter waves applications [3] [4]. Our study concerns the analysis of right bends of rectangular waveguides under SIW technology by the HFSS code, in order to simulate different chamfrain positions, through the analysis of the transmission coefficient S21. In order to reduce losses of the performance, it is usual to chamfrain the external wall of the waveguide. Thus, through this modeling, we have confirmed the optimal position [5] of the chamfrain. A good agreement between HFSS simulations and reference results has been obtained.
The wireless sensor networks (WSNs) are composed of nodes communicating over a wireless media, wi... more The wireless sensor networks (WSNs) are composed of nodes communicating over a wireless media, without the need for physical infrastructure. In this type of topology, all nodes cooperate to ensure the proper management of the network (control, routing, ...). Fully distributed nature of such networks is the problem of performance (due to the calculation of routes) as well as problems related to the security of exchanges between nodes. In regard to performance due to packet routing, we distinguish protocols inspired by ant colonies that give in most cases, better results. In this paper we present a protocol based on an ant colony to calculate dynamic routes and a cooperation mechanism which allows better quality of service (QoS) management problem in WSNs. Thus, we proposed Qos_Aco a routing protocol based on Ants colony with QoS support requirements in WSNs. Our approach allows to find the path with the least delay (end to end), the more bandwidth, and the shortest number of hops for...
In this paper, the concept of substrate integrated waveguide (SIW) technology is used to design f... more In this paper, the concept of substrate integrated waveguide (SIW) technology is used to design filter for 30 GHz communication systems. SIW is created in the substrate of RT/Duroid 5880 having relative permittivity = 2.2 and loss tangent tanφ = 0.0009. Four Via are placed on the century filter the structures of SIW are modeled using and have been optimized in software HFSS (High Frequency Structure Simulator), à transition is designed for a Ka-band transceiver module with a 28.5GHz center frequency, and then the results are verified using another simulation CST Microwave Studio (Computer Simulation Technology). The return loss are less than -18 dB, and 13 dB respectively. The insertion loss is divided equally -1.2 dB and -1.4 respectively.
This work proposes a new compact triple-band triangular patch antenna for RF energy harvesting ap... more This work proposes a new compact triple-band triangular patch antenna for RF energy harvesting applications in IoT devices. It is realized on Teflon glass substrate with a thickness of 0.67 mm and a relative permittivity of 2.1. Four versions of this antenna have been designed and realized with inclinations of 0°, 30°, 60° and 90° to study the impact of the tilting on their characteristics (S11 parameter, radiation pattern, gain) and to explore the possibilities of their implementation in the architectures of electronic equipment according to the available space. The antenna is also realized on waterproof paper with a thickness of 0.1 mm and a relative permittivity of 1.4 for biomedical domain. All the antennas (vertical antenna, tilted antennas and antenna realized on waterproof paper) have a size of 39 × 9 mm2 and cover the 2.45 GHz and 5.2 GHz Wi-Fi bands and the 8.2 GHz band. A good agreement is obtained between measured and simulated results. Radiation patterns show that all th...
In this paper, a new RF Energy Harvesting (RF-EH) system for Wireless Sensor Network (WSN) feedin... more In this paper, a new RF Energy Harvesting (RF-EH) system for Wireless Sensor Network (WSN) feeding is proposed. It is based on two different monitored architectures using switch circuits controlled by the input powers. One architecture is more adapted to high input powers and the other to low input powers. The two different architectures and the system are designed and realized on Teflon glass substrate with a relative permittivity of 2.1 and thickness of 0.67 mm. They are tested separately as a function of the distance from the relay antenna. A new multiband antenna with a size of 40 × 30 mm2 is used for both architectures and the system. The measured antenna gains are 2.7 dB, 2.9 dB, and 2.55 dB for the frequencies of 1.8 GHz, 2.1 GHz, and 2.66 GHz corresponding to the mobile communication networks, respectively. The rectifier consists of two Schottky diodes forming a full-wave rectifier and voltage doubler. The maximum measured RF-to-DC conversion efficiency is 71.5%. The propose...
Advances in Multidisciplinary Medical Technologies ─ Engineering, Modeling and Findings, 2020
DNA biochip technology (especially in the optical field) can study a large amount of nucleic acid... more DNA biochip technology (especially in the optical field) can study a large amount of nucleic acid records at high throughput. It makes viable the simultaneous scrutiny of quite a few of tens of thousands of genes belonging to a healthy or diseased biological sample in terms of its genome (DNA). This article overviews optical DNA biochips as well as the Network Time Protocol (NTP) protocol deployment for synchronization among the collection database and the optical biochip automaton via the ASTM Elecsys protocol for better real-time detection with diagnosis of genetically mutated cancer. The present study utilizes the UNIX Server platform and NTP to synchronize communication between servers and optical DNA. Section 7.4 brings in automates.
The wireless mesh network is a new emerging technology that will change the world of industrial n... more The wireless mesh network is a new emerging technology that will change the world of industrial networks connectivity to more efficient and profitable. Mesh networks consist of static wireless nodes and mobile customer; have emerged as a key technology for new generation networks. The QoS is designed to promote and support multimedia applications (audio and video), real time (ToIP, VoIP). However guarantee of QoS on wireless networks is a difficult problem by comparison at its deployment in a wired IP network. The reason is the random mobility of nodes, the nature of wireless channel (interference), the multi-hop communication and the lack of a central coordinating authority. Wireless Mesh Networks (WMNs) are commonly considered the most suitable architecture because of their versatility that allows flexible configurations. Different studies have proposed number of protocols in different layers of model TCP/IP to enhance transmission of data and its QoS. This paper mainly focuses on...
Etude comparative des paramètres géométriques et électriques du transistor MESFET bigrille en GaA... more Etude comparative des paramètres géométriques et électriques du transistor MESFET bigrille en GaAs et en 4H-SiC
Technology and Economics of Smart Grids and Sustainable Energy, 2021
Nowadays, electrical grids are using information and communication technologies for providing int... more Nowadays, electrical grids are using information and communication technologies for providing intelligence in electrical grids, since alternative energy sources are increasing to meet the world's energy consumption demand. Interest in Internet of Things (IoT) is lastingly growing and may involve more data-sensitive projects when applied in smart micro-grids (SMGs), and security is a priority to be ensured for power distribution and consumption. Moreover, standards for IoT platforms should be optimized for monitoring such consumption and controlling grid resources, which present more demanding challenges. In such context, this work aims to adopt an appropriate PV-based energy generation system feeding a remote telecom network (RTN), via evaluating its performance, and monitor a related smart micro-grid (SMG) to offer a secure and energy-efficient management for RTNs. Simulink simulations have proved DC/DC converters as the best choice for future telecoms applications by using PV systems. Boost converters reveal to be suitable for PV systems while optimizing a fewer transformers electric energy conversion. A focus is also on how to detect and counteract attacks to prevent power theft/loss while feeding RTNs, showing that the best security choice is the use of Snort to prevent from inside net LAN, and ASA firewall to obstruct attacks from outside.
Methode des elements finis : application a l'etude des caracteristiques electromagnetiques des resonateurs dielectriques
Etude par la methode des elements finis des caracteristiques electromagnetiques (frequence de res... more Etude par la methode des elements finis des caracteristiques electromagnetiques (frequence de resonance, distribution du champ des modes, coefficient de qualite a vide) d'une structure composee de plusieurs resonateurs dielectriques. Etude du couplage entre resonateurs et elements d'excitation et de detection. Visualisation de l'energie des modes par utilisation des cristaux liquides et de la thermographie ir
2020 2nd International Workshop on Human-Centric Smart Environments for Health and Well-being (IHSH), 2021
Among the important challenges for Vehicular Adhoc Network (VANET) Security and Privacy. Most of ... more Among the important challenges for Vehicular Adhoc Network (VANET) Security and Privacy. Most of the solutions for privacy in vanet are based on pseudonyms. And the pseudonyms are digital certificates with very limited information, valid for a short time, and hide the identity of the vehicle. The pseudonym operations (issuing, changing, and revoking) are centralized by a certification authority. In our paper, we propose a fully distributed management for pseudonyms in VANETs. We use the blockchain technology to perform the different operations related to pseudonyms. Our proposal use two blockchains, one for registering pseudonyms, the second for revoked ones. The vehicles are considered as miners in the blockchain. Our approach makes the vehicles in VANET more autonomous in managing the security, and reduce the exchanged data with a centralized authority (Certificate Authority-CA)
International Journal of Electronics and Telecommunications, 2017
The waveguide filter structure is treated by two softwares (HFSS (High Frequency Structure Simula... more The waveguide filter structure is treated by two softwares (HFSS (High Frequency Structure Simulator) and CST (Computer Simulation Technology)). Numerical example is given in this article to demonstrate, step by step, the application of the approach to the design of resonator, direct coupled waveguide and microstrip filters based on electromagnetic (EM) simulations. For this design procedure, the filter structure is simulated by successively adding one resonator at a time. To continue the work illustrates how to design a fourth order coupled resonator based rectangular waveguide circuit in the traditional way. With a large number of variables, such tuning work consumes a lot of time and the convergence of the final result is not guaranteed. A fourth order X-band bandpass filter with a center frequency of 11 GHz and a fractional bandwidth FBW = 0,0273 is designed using this procedure and presented here as an example. The simulated results by CST are presented and compared withthe res...
Wireless Sensor Networks (WSN) is designed to collect information across a large number of limite... more Wireless Sensor Networks (WSN) is designed to collect information across a large number of limited battery sensor nodes. Therefore, it is important to minimize the energy consumption of each node, which leads to the extension of the network life. Our goal is to design an intelligent WSN that collects as much information as possible to process it intelligently. To achieve this goal, an agent has been migrated to each node in order to process the information and to cooperate with these neighboring nodes while Mobile Agents (MA) can be used to reduce information between nodes and send those to the base station (Sink). This work proposes to use communication architecture for wireless sensor networks based on the Multi Agent System (MAS) to ensure optimal information collection. The collaboration of these agents generates a simple message that summarizes the important information in order to transmit it by a mobile agent. To reduce the size of the MA, the nodes of the network have been g...
In Smart Grid, data aggregation is considered as an essential paradigm in assessing information a... more In Smart Grid, data aggregation is considered as an essential paradigm in assessing information about current energy usage. To achieve the privacy-preserving goal, several homomorphic-based solutions have been proposed. However, these solutions either consider one-dimensional information or use costly pairing computation in order to ensure source authentication. In fact, smart grid data is likely to be multidimensional (e.g. time, purpose, etc.) for more accurate control. In addition, the aggregation node in smart grid needs to verify data that come from several smart meters in a residential area; hence, the verification must be cost-efficient. In this paper, we propose a scheme that considers multidimensional aggregation with privacy preserving and an efficient verification of smart grid data. The proposal is based on elliptic curve cryptography along with homomorphic encryption and without pairings. The performance analysis shows the efficiency of the scheme for smart grid communications in comparison to existing schemes. For instance, we show that, when an aggregator node is responsible of 600 smart meters, it spends approximately 14s to verify the data in pairing-based schemes, while only 0.3s is needed for verification within the proposed scheme.
Mobile communication systems present an actuality subject in academic and industrial research act... more Mobile communication systems present an actuality subject in academic and industrial research activities due to several phenomena such as interferences, multipath, fading and shadowing. All this lead to a severe perturbation on handover mechanism which depends on specific reports, essentially, reference signal received power (RSRP) and signal-to-interference and noise ratio (SINR). In this paper, we design a new technique in handover domain; it consists of combining energy detection method used in cognitive radio with least mean square (LMS) process in order to prognosticate the handover impact in a realistic scenario of heterogeneous LTE network. More exactly, technique sense of the word "triggering" will be changed to a probability of detection. The proposed algorithm cycle follows two main steps; Firstly, predict at what time the absence of spectrum (primary user) will occur, using a predicted sensing probability. Secondly, search others spectrums in this time by calculating the probability of detection for each sensed signal and hand-off secondary user in the best spectrum. The results achieved of the simulation are evaluating, it shows that the proposed method predict the original probability of detection correctly with minimal errors and select the best spectrum successfully contraly to standard handover process.
International Journal of Advanced Computer Science and Applications, 2017
To examine the long-term causality between Cardiorespiratory Electromyography Galvanic signals fo... more To examine the long-term causality between Cardiorespiratory Electromyography Galvanic signals for 17 drivers taken from Stress Recognition in Automobile Drivers database. Methods: Two statistical methods, co-integration to reveal an eventual existence of a long-term relationship between ECG (Electrocardiograph), EMG (electromyography), GSR (galvanic skin resistance), heart rate (HR) and respiration, well as the Application of the model of Granger causality. Results: ECG shows certain dependence to EMG, GSR, heart rate and respiration. The results for ECG dependent suggest that an increase of 1% in EMG, FOOTGSR, HAND GSR, HR and RESPIRATION implies a variation of ECG which take a value respectively of 0.016248%, 0.007241%, 0.028366%, 0.000511% and 0.000110% in the within dimension based on the FMOLS (Fully Modified Ordinary Least Squares). With same way, the result for ECG suggest that an increase of 1% in EMG, FOOT GSR, HAND GSR, HR and RESPIRATION implies a variation of ECG which take a value respectively, of 0.065684%, 0.014534%, 0.032800%, 0.000304%, 0.005986% in the between dimension based on the same method. The results of panel Granger causality show a bi-directional relationship between ECG and FOOT GSR, HAND GSR and respiration signals, it must be noted as a unidirectional causality from EMG to ECG. Conclusion: This study shows the long-term interaction between the bio signals, and reveal how the understanding of these interactions can help the doctors to understand the risks that may exist between these interactions. The main advantage of a multidimensional and multivariate model is to solve a multitude of problems that prevent doctors to treat the patients better and is not the case for studies in two dimensions.
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Papers by Mohammed Feham