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Performance of Analysis Cognitive Radio with Cooperative Sensing under Malicious Attacks over Nakagami Faded Channels

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Wireless Engineering and Technology 2016年第2期7卷 67-74页

作者： Hagar O. Shazly Asmaa Saafan hesham el badawy Hadia M. el Hennawy Faculty of Engineering Ain Shams University Cairo Egypt National Telecommunication Institute (NTI) Cairo Egypt

The different realistic propagation channels are faced frequently the multipath fading environments. The main goal of this system design (cognitive radio network) is to improve the efficiency of spectrum access on a non-interfering basis. This system achieves high utilization for the limited spectrum in order to fulfill needs for all users’ demands which are considered as a problem in wireless communications due to rapidly increasing in wireless applications and service. This system is exposed to attack due to the vulnerabilities existence in this system. So, the main outcome of this paper is to investigate the performance of the cooperative sensing in cognitive radio networks under malicious attacks over different channel impairments, and to illustrate the most suitable individual probability of detection in real faded channel by using Nakagami model. This paper illustrates the effectiveness of the attacks and fading on the performance of spectrum sensing process.

关键词： Cognitive Radio Cooperative Sensing Malicious Attacks Nakagami Faded Channels

Performance Assessment for LTE-Advanced Networks with Uniform Fractional Guard Channel over Soft Frequency Reuse Scheme

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Wireless Engineering and Technology 2013年第4期4卷 161-170页

作者： Mahammad A. Safwat hesham M. el-badawy Ahmad Yehya Hosni el-Motaafy Department of electrical Engineering Alazhar University Cairo Egypt Department of electronics and Computer Engineering HIT Egypt Network Planning Department National Telecommunication Institute Cairo Egypt

Dropping probability of handoff calls and blocking probability of new calls are two important Quality of Service (QoS) measures for LTE-Advanced networks. Applying QoS for Cell edge users in soft frequency reuse scheme in LTE system is a challenge as they already suffer from limited resources. Assigning some resources for handover calls may enhance dropping probability but this is in price of degradation in the blocking probability for new calls in cell-edge. Uniform Fractional Guard Channel (UFGC) is a call admission policy that provides QoS without reserving resources for handover calls. In this paper, the performance of Soft Frequency Reuse (SFR) in presence of Uniform Fractional Guard Channel (UFGC) will be investigated using queuing analysis. The mathematical model and performance metrics will be deduced in this assessment. The impact of UFGC will be evaluated in edge and core part separately. Then the optimal value for the parameter of UFGC will be obtained to minimize the blocking probability of new calls with the constraint on the upper bound on the dropping probability of handoff calls.

关键词： Soft Frequency Reuse Queuing Uniform Fractional Guard Channel

Novel Optimized Cross-Layer Design with Maximum Weighted Capacity Based Resource Allocation for AMC/HARQ Wireless Networks

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Wireless Engineering and Technology 2013年第2期4卷 77-86页

作者： Reham A. el-Mayet hesham M. el-badawy Salwa H. elramly electronic and Communication Department Ain Shams University Cairo Egypt National Telecommunication Institute Cairo Egypt

To provide quality-of service (QoS) guarantees for heterogeneous applications, most recent wireless communications technologies and standards combine the error-correcting capability of hybrid automatic repeat request (HARQ) schemes at the data link layer (DLL) with the adaptation ability of the adaptive modulation and coding (AMC) modes at the physical layer (PHY) layer. This paper aims to investigate the aggregated system capacity as well as the breakdown of this capacity for different ACM modes in each HARQ scheme. This investigation was done by using maximum weighted capacity (MWC) resource allocation at the PHY layer in conjunction with a novel packet error rate (PER)-based scheduling at the medium access control (MAC) layer. As a result, the dominant AMC mode corresponding to channel SNR was available.

关键词： AMC Cross-Layer Design HARQ Nakagami-m Fading Channel QoS

Energy Efficiency Behavior in Heterogeneous Networks under Various Operating Situations of Cognitive Small Cells

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Wireless Engineering and Technology 2015年第1期6卷 9-23页

作者： Amr A. Fahmy Asmaa M. Saafan hesham M. el-badawy Salwa el-Ramly Faculty of Engineering Ain-Shams University Cairo Egypt National Telecommunication Institute (NTI) Cairo Egypt

Recently, several approaches were followed for the enhancement and better resource utilization in mobile networks;this is to achieve energy efficient consumption for production and delivery of an information bit. Using Cognitive Femto cells (as a member of the small base stations’ family) proves that, it is an efficient solution for achieving this goal[1]. The use of Energy Efficiency term η has become one of the major indices for measuring the performance of these systems. η is the measure of the overall system Capacity (C)?in bps/Hz versus the Consumed Energy (E) in Joules [2]. In consistence with many researches, analytic models and empirical measurements, η will be investigated throughout the course of this work. Cognitive Base Stations (CBS) (as an element of the system model) which performs the traffic offloading operations is proved to enhance η performance. In this work, a combination of both analytic and simulation models are used to construct a practical system model. The obtained model is then used to illustrate the effect of different operational parameters that are involved in the η problem. On the other hand, the current paper tries to focus on the selection criteria that may be used to design the cooperative cognitive networks in order to achieve the best η indices. Both of CBSs radii as well as the inter-separation distances (between CBSs and MBS location) are examined to obtain best η index for different operation scenarios;in addition, both of capacity and energy consumption are taken into consideration based on practical operating measures. This work proposed several nonlinear equations with fixed parameters to be used by field engineers to achieve the results with minimum reduced computation complexity. So, the current work may be of importance for the regulator bodies as well as the cognitive mobile operators.

关键词： Energy Efficiency Capacity Energy Cognitive Radio Wireless Communications Green Radio

Mu-based trajectory tracking control for a quad-rotor UAV

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Control Theory and Technology 2022年第4期20卷 536-554页

作者： Abdallah Hossam Ayman el-badawy Mechatronics Engineering Department German University in Cairo5th SettlementNew CairoCairo 11835Egypt

In this paper,the design and application of a robust mu-synthesis-based controller for quad-rotor trajectory tracking are *** proposed design approach guarantees robust performance over a weakly nonlinear range of operation of the quad-rotor,which is a practical range that suits various *** controller considers different structured and unstructured uncertainties,such as unmodeled dynamics and perturbation in the *** controller also provides robustness against external disturbances such as wind gusts and wind *** proposed controller is fixed and linear;therefore,it has a very low computational ***,the controller meets all design specifications without *** validate this control strategy,the proposed approach is compared to a linear quadratic regulator(LQR)controller using a high-fidelity quad-rotor simulation *** addition,the experimental results presented show the validity of the proposed control strategy.

关键词： Mu-synthesis Robust control H-infinity Trajectory tracking

3D finite element analysis of composite noise barrier con- structed of polyurethane products

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Frontiers of Structural and Civil Engineering 2017年第1期11卷 100-110页

作者： Ben DAEE hesham el NAGGAR Department of Civil and Environmental Engineering the University of Western Ontario London ON N6A 5B9 Canada

This paper presents a numerical investigation on the structural performance of an innovative noise barrier consisting of poly-block, rigid polyurethane foam （RPF） and polyurea. The mechanical characteristics of RPF as well as the flexural resistance of the proposed wall system （poly-wall） were established and presented in another study. The experimental results are used in the current study to develop, calibrate and verify 3D finite element （FE） models of the wall system. The components of the poly-wall including steel rebars, poly-blocks and RPF cores were simulated and then verified using the results of experiments conducted on the wall components. The results of numerical analysis exhibited a satisfactory agreement with the experimental outcomes for the entire wall system. The verified numerical models were then used to conduct a parametric study on the performance of poly-wall models under uniform wind load and gravity load. The findings of the current study confirmed that the structural performance of poly-wall is satisfactory for noise barrier application. Simulation techniques for improvement of the numerical analysis of multi-martial 3D FE models were discussed.

关键词： 3D finite element sound wall rigid polyurethane foam poly-wall numerical model calibration

Congruence Pairs of Decomposable MS-Algebras

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Chinese Annals of Mathematics,Series B 2021年第4期42卷 561-574页

作者： Sanaa el-ASSAR Abd el-Mohsen badawy Department of Mathematics Faculty of ScienceTanta UniversityTantaEgypt

In this paper,the authors first introduce the concept of congruence pairs on the class of decomposable MS-algebras generalizing that for principal MS-algebras(see[13]).They show that every congruence relationθon a decomposable MS-algebra L can be uniquely determined by a congruence pair(θ_(1),θ_(2)),whereθ_(1)is a congruence on the de Morgan subalgebra L^(∞)of L andθ_(2)is a lattice congruence on the sublattice D(L)of *** obtain certain congruence pairs of a decomposable MS-algebra L via central elements of ***,they characterize the permutability of congruences and the strong extensions of decomposable MS-algebras in terms of congruence pairs.

关键词： MS-Algebras Decomposable MS-algebras Congruence pairs Strong extension Permutability Congruence lattices

Fractional Optimal Control of Navier-Stokes Equations

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Computers, Materials & Continua 2020年第8期64卷 859-870页

作者： Abd-Allah Hyder M.el-badawy King Khalid University College of ScienceDepartment of MathematicsP.O.Box 900461413AbhaSaudi Arabia Department of Engineering Mathematics and Physics Faculty of EngineeringAl-Azhar UniversityCairo11371Egypt Mathematics Department Al-Azhar UniversityCairoEgypt

In this paper,the non-stationary incompressible fluid flows governed by the Navier-Stokes equations are studied in a bounded *** study focuses on the time-fractional Navier-Stokes equations in the optimal control subject,where the control is distributed within the domain and the time-fractional derivative is proposed as Riemann-Liouville *** addition,the control object is to minimize the quadratic cost *** using the Lax-Milgram lemma with the assistance of the fixed-point theorem,we demonstrate the existence and uniqueness of the weak solution to this ***,for a quadratic cost functional subject to the time-fractional Navier-Stokes equations,we prove the existence and uniqueness of optimal ***,via the variational inequality upon introducing the adjoint linearized system,some inequalities and identities are given to guarantee the first-order necessary optimality conditions.A direct consequence of the results obtained here is that when a→1,the obtained results are valid for the classical optimal control of systems governed by the Navier-Stokes equations.

关键词： Optimal control lax-milgram lemma fixed point theorem navier-stokes equations

Comparison of bacterial community structures in two systems of a sewage treatment plant using PCR-DGGE analysis

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Journal of Environmental Sciences 2011年第12期23卷 2049-2054页

作者： Abd el-Latif hesham Rong Qi Min Yang State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Genetics Department Faculty of Agriculture Assiut University Assiut Egypt

The combination of PCR amplification of 16S rRNA genes with denaturing gradient gel electrophoresis （DGGE） analysis was used to reveal the compositions and dynamics of bacterial communities in a sewage treatment plant with two systems, i.e., an anoxic- anaerobic-aerobic system （inverted A2O） and an anaerobic-anoxic-aerobic one （conventional A2O） over a period from February to July 2009, during which both systems experienced serious sludge bulking problems. The DGGE patterns showed that there were many common bands in both systems, suggesting the high similarity of bacterial communities of the two systems. Meanwhile, the moving window correlation analysis showed that the two systems experienced different microbial community structure changes during the period, which might be related with the different situations of the occurrence and disappearance of sludge bulking, as being reflected by sludge volume index （SVI） values. Major bands of DGGE patterns of sludge samples were further sequenced. Phylogenetic affiliation indicated that the majority of the sequences obtained were affiliated with Actinobacteria, Firmicutes, Bacteroidetes/Chlorobi group and α- and β-Proteobacteria. Two sequences showed high similarities to typical filamentous bacteria Microthrix parvicella and Nostocoida limicola I, indicating that these bacterial species have been involved in the sludge bulking problems.

关键词： PCR-DGGE bacterial community activated sludge sludge bulking sewage treatment plant