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Fading Channels Parametric Data Simulation Supported by Real Data from Outdoor Experiments

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Journal of Signal and Information Processing 2017年第3期8卷 113-131页

作者： Azra Kapetanovic mohamed A. zohdy Redhwan Mawari Department of Electrical and Computer Engineering Oakland University Rochester MI USA

Optimizing the estimates of received power signals is important as it can improve the process of transferring an active call from one base station in a cellular network to another base station without any interruptions to the call. The lack of effective techniques for estimation of shadow power in fading mobile wireless communication channels motivated the use of Kalman Filtering (KF) as an effective alternative. In our research, linear second-order state space Kalman Filtering was further investigated and tested for applicability. We first created simulation models for two KF-based estimators designed to estimate local mean (shadow) power in mobile communications corrupted by multipath noise. Simulations were used extensively in the initial stage of this research to validate the proposed method. The next challenge was to determine if the models would work with real data. Therefore, in [1] we presented a new technique to experimentally characterize the wireless small-scale fading channel taking into consideration real environmental conditions. The two-dimensional measurement technique enabled us to perform indoor experiments and collect real data. Measurements from these experiments were then used to validate simulation models for both estimators. Based on the indoor experiments, we presented new results in [2], where we concluded that the second-order KF-based estimator is more accurate in predicting local shadow power profiles than the first-order KF-based estimator, even in channels with imposed non-Gaussian measurement noise. In the present paper, we extend experiments to the outdoor environment to include higher speeds, larger distances, and distant large objects, such as tall buildings. Comparison was performed to see if the system is able to operate without a failure under a variety of conditions, which demonstrates model robustness and further investigates the effectiveness of this method in optimization of the received signals. Outdoor experimental results

关键词： Kalman Filtering Small-Scale Fading Large-Scale Fading

Interactive Kalman Filtering for Differential and Gaussian Frequency Shift Keying Modulation with Application in Bluetooth

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Journal of Signal and Information Processing 2012年第1期3卷 63-76页

作者： Mahdi N. Ali mohamed A. zohdy Electrical and Computer Engineering Department Oakland University Rochester USA.

Some applications are constrained only to implement low cost receivers. In this case, designers are required to use less complex and non-expensive modulation techniques. Differential Quadrature Phase Shift Keying (DQPSK) and Gaussian Frequency Shift Keying (GFSK) can be non-coherently demodulated with simple algorithms. However, these types of demodulation are not robust and suffer from poor performance. This paper proposes a new method to enhance the performance of DQPSK and GFSK using Interactive Kalman Filtering (IKF) technique, in which a one Unscented Kalman Filter (UKF) and two Kalman Filters (KF) are coupled to optimize the demodulated signals. This method consists of simple but very effective algorithms without adding complexity to the demodulators comparing to other very complex methods. UKF is used in this method due to its superiority in approximating and estimating nonlinear systems and its ability to handle non-Gaussian noise environments. The proposed method has been validated by creating a MATLAB/SIMULINK Bluetooth system model, in which the IKF is integrated into the receiver, which implement both DQPSK and GFSK, and run simulation in Gaussian and Non-Gaussian noise environments. Results have shown the effectiveness of this method in optimizing the received signals, and that the UKF outperforms the Extended Kalman Filter (EKF).

关键词： Interactive Kalman Filtering Unscented Kalman Filter Extended Kalman Filter Differential Quadrature Phase Shift Keying Gaussian Frequency Shift Keying Bluetooth

Real Time Vehicular Traffic Simulation for Black Hole Attack in the Greater Detroit Area

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Journal of Information Security 2020年第1期11卷 71-80页

作者： Abdulaziz Alshammari mohamed a.zohdy Debatosh Debnath George Corser College of Computer and Information Sciences IMSIU Riyadh KSA Electrical and Computer Engineering Department Oakland University Rochester MI USA Computer Science and Engineering Department Oakland University Rochester MI USA Department of Computer Science & Information Systems Saginaw Valley State University University Center MI USA

Vehicular Ad-hoc Networks (VANETs) technology has recently emerged, and gaining significant attention from the research because it is promising technologies related to Intelligent Transportation System (ITSs) and smart cities. Wireless vehicular communication is employed to improve traffic safety and to reduce traffic congestion. Each vehicle in the ad-hoc network achieves as a smart mobile node categorized by high mobility and forming of dynamic networks. As a result of the movement of vehicles in a continuous way, VANETs are vulnerable to many security threats so it requisites capable and secure communication. Unfortunately, Ad hoc networks are liable to varied attacks like Block Hole attacks and Grey Hole attacks, Denial of service attacks, etc. Among the most known attacks are the Black Hole attacks while the malicious vehicle is able to intercept the data and drops it without forwarding it to the cars. The main goal of our simulation is to analyze the performance impact of black hole attack in real time vehicular traffic in the Greater Detroit Area using NS-2 and SUMO (Simulation of Urban). The simulation will be with AODV protocol.

关键词： Black Hole Attacks Vehicular Ad Hoc Networks AODV Protocol Simulation SUMO Greater Detroit Area

Optimal Sizing of Solar/Wind Hybrid Off-Grid Microgrids Using an Enhanced Genetic Algorithm

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Journal of Power and Energy Engineering 2018年第5期6卷 64-77页

作者： Abdrahamane Traoré Hatem Elgothamy mohamed A. zohdy Department of Electrical and Computer Engineering Oakland University Rochester MI USA

This paper presents a method for optimal sizing of an off-grid hybrid microgrid (MG) system in order to achieve a certain load demand. The hybrid MG is made of a solar photovoltaic (PV) system, wind turbine (TW) and energy storage system (ESS). The reliability of the MG system is modeled based on the loss of power supply probability (SPSP). For optimization, an enhanced Genetic Algorithm (GA) is used to minimize the total cost of the system over a 20-year period, while satisfying some reliability and operation constraints. A case study addressing optimal sizing of an off-grid hybrid microgrid in Nigeria is discussed. The result is compared with results obtained from the Brute Force and standard GA methods.

关键词： Optimization Off-Grid Microgrid Renewable Energy Energy Storage Systems (ESS) Solar Photovoltaic (PV) Wind Battery Hybrid Genetic Algorithm (GA)

Nonlinear Control of Interior PMSM Using Control Lyapunov Functions

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Journal of Power and Energy Engineering 2014年第1期2卷 17-26页

作者： Maha Sabra Bashar Khasawneh mohamed A. zohdy Department of Electrical and Computer Engineering Oakland University Rochester USA Department of Electrical and Computer Engineering Oakland University Rochester USA.

In this paper, we introduce a non-linear torque control for an interior permanent-magnet synchronous motor (IPMSM). The nonlinear control is based on a Control Lyapunov Function (CLF) technique. The proposed stabilizing feedback law for the IPMSM drive is a damping control method and is shown to be globally asymptotically stable. The CLF method takes the system nonlinearities into account in the control system design stage. Such nonlinearities are due to the cross coupling between the q and the q currents in addition to the system parameters like the inductances and the flux linkages. The complete IPMSM drive incorporating the proposed CLF has been successfully simulated in a plant model for both motor and inverter. The performance of the proposed drive is investigated in simulation at different operating conditions. It is found that the proposed control technique provides a good torque control performance for the IPMSM drive ensuring the global stability. In later work, we are planning to investigate other phenomena such as magnetic saturation, nonlinear loads, mechanical friction and flexibilities.

关键词： Nonlinear Control Interior Permanent Magnet Motor (IPMSM) Control Lyapunov Function (CLF) IPMSM Experimental Parameter Determination

Nonlinear Control of Chaotic Forced Duffing and Van der Pol Oscillators

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International Journal of Modern Nonlinear Theory and Application 2017年第1期6卷 26-37页

作者： Mohammed Alghassab Amr Mahmoud mohamed A. zohdy Electrical and Computer Engineering Department Oakland University Rochester MI USA College of Engineering Shaqra University Riyadh Saudi Arabia

This paper discusses a novel technique and implementation to perform nonlinear control for two different forced model state oscillators and actuators. The paper starts by discussing the Duffing oscillator which features a second order non-linear differential equation describing complex motion whereas the second model is the Van der Pol oscillator with non-linear damping. A first order actuator is added to both models to expand on the chaotic behavior of the oscillators. In order to control the system without comprising linearization, Lyapunov non-linear control was used. A control Lyapunov function was tailored to the system. This led to improved maneuverability of the controller and the performance of the overall system. The controller was found to be highly efficient in system tracking and had swift response time. Simulations were performed on both the uncontrolled and controlled cases. Both simulation results ultimately confirmed the effectiveness of the proposed controller.

关键词： Duffing Oscillator Lyapunov Function Nonlinear Control Van der Pol Oscillator

Paralleled DC-DC Power Converters Sliding Mode Control with Dual Stages Design

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Journal of Power and Energy Engineering 2014年第2期2卷 1-10页

作者： Bashar Khasawneh Maha Sabra mohamed A. zohdy Department of Electrical and Computer Engineering Oakland University Rochester Michigan USA.

This paper proposes the new cascaded series parallel design for improved dynamic performance of DC-DC buck boost converters by a new Sliding Mode Control (SMC) method. The converter is controlled using Sliding Mode Control method that utilizes the converter’s duty ratio to determine the skidding surface. System modeling and simulation results are presented. The results also showed an improved overall performance over typical PID controller, and there was no overshoot or settling time, tracking the desired output nicely. Improved converter performance and robustness were expected.

关键词： DC-DC Converters Paralleled Converter DC-DC Control Efficiency Improvement of DC-DC Sliding Mode Control (SMC) Hyper Plane Design Variable Structure Control (VSC)

Sliding Mode Control for Singularly Perturbed Systems Using Accurate Reduced Model

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International Journal of Modern Nonlinear Theory and Application 2021年第1期10卷 1-12页

作者： Ayman E. M. Ahmed mohamed zohdy Research Department Egyptian Armed Force Cairo Egypt Electrical and Systems Engineering Oakland University Rochester MI USA

In order to deal with unmodeled dynamics in large vehicle systems, which have an ill condition of the state matrix, the use of model order reduction methods is a good approach. This article presents a new construction of the sliding mode controller for singularly perturbed systems. The controller design is based on a linear diagonal transformation of the singularly perturbed model. Furthermore, the use of a single sliding mode controller designed for the slow component of the diagonalized system is investigated. Simulation results indicate the performance improvement of the proposed controllers.

关键词： Singular Perturbation Sliding Mode Control Diagonalization Method

Classification Approach for Intrusion Detection in Vehicle Systems

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Wireless Engineering and Technology 2018年第4期9卷 79-94页

作者： Abdulaziz Alshammari mohamed A. zohdy Debatosh Debnath George Corser Engineering and Computer Science Department Oakland University Rochester Hills MI USA Department of Computer Science & Information Systems Saginaw Valley State University University Center MI USA

Vehicular ad hoc networks (VANETs) enable wireless communication among Vehicles and Infrastructures. Connected vehicles are promising in Intelligent Transportation Systems (ITSs) and smart cities. The main ob-jective of VANET is to improve the safety, comfort, driving efficiency and waiting time on the road. VANET is unlike other ad hoc networks due to its unique characteristics and high mobility. However, it is vulnerable to various security attacks due to the lack of centralized infrastructure. This is a serious threat to the safety of road traffic. The Controller Area Network (CAN) is a bus communication protocol which defines a standard for reliable and efficient transmission between in-vehicle parts simultaneously. The message moves through CAN bus from one node to another node, but it does not have information about the source and destination address for authentication. Thus, the attacker can easily inject any message to lead to system faults. In this paper, we present machine learning techniques to cluster and classify the intrusions in VANET by KNN and SVM algorithms. The intrusion detection technique relies on the analysis of the offset ratio and time interval between the messages request and the response in the CAN.

关键词： CAN-Bus IDS KNN SVM Machine Learning DoS Attack Fuzzy Attack