Electric Vehicle (EV) adoption is rapidly increasing, necessitating efficient and precise methods for predicting EV charging requirements. The early and precise prediction of the battery discharging status is helpful ...Electric Vehicle (EV) adoption is rapidly increasing, necessitating efficient and precise methods for predicting EV charging requirements. The early and precise prediction of the battery discharging status is helpful to avoid the complete discharging of the battery. The complete discharge of the battery degrades its lifetime and requires a longer charging duration. In the present work, a novel approach leverages the Edge Impulse platform for live prediction of the battery status and early alert signal to avoid complete discharging. The proposed method predicts the actual remaining useful life of batteries. A powerful edge computing platform utilizes Tensor Flow-based machine learning models to predict EV charging needs accurately. The proposed method improves the overall lifetime of the battery by the efficient utilization and precise prediction of the battery status. The EON-Tuner and DSP processing blocks are used for efficient results. The performance of the proposed method is analyzed in terms of accuracy, mean square error and other performance parameters.展开更多
In the contemporary era,the global expansion of electrical grids is propelled by various renewable energy sources(RESs).Efficient integration of stochastic RESs and optimal power flow(OPF)management are critical for n...In the contemporary era,the global expansion of electrical grids is propelled by various renewable energy sources(RESs).Efficient integration of stochastic RESs and optimal power flow(OPF)management are critical for network optimization.This study introduces an innovative solution,the Gaussian Bare-Bones Levy Cheetah Optimizer(GBBLCO),addressing OPF challenges in power generation systems with stochastic RESs.The primary objective is to minimize the total operating costs of RESs,considering four functions:overall operating costs,voltage deviation management,emissions reduction,voltage stability index(VSI)and power loss mitigation.Additionally,a carbon tax is included in the objective function to reduce carbon emissions.Thorough scrutiny,using modified IEEE 30-bus and IEEE 118-bus systems,validates GBBLCO’s superior performance in achieving optimal solutions.Simulation results demonstrate GBBLCO’s efficacy in six optimization scenarios:total cost with valve point effects,total cost with emission and carbon tax,total cost with prohibited operating zones,active power loss optimization,voltage deviation optimization and enhancing voltage stability index(VSI).GBBLCO outperforms conventional techniques in each scenario,showcasing rapid convergence and superior solution quality.Notably,GBBLCO navigates complexities introduced by valve point effects,adapts to environmental constraints,optimizes costs while considering prohibited operating zones,minimizes active power losses,and optimizes voltage deviation by enhancing the voltage stability index(VSI)effectively.This research significantly contributes to advancing OPF,emphasizing GBBLCO’s improved global search capabilities and ability to address challenges related to local minima.GBBLCO emerges as a versatile and robust optimization tool for diverse challenges in power systems,offering a promising solution for the evolving needs of renewable energy-integrated power grids.展开更多
Accurately characterizing the wireless small-scale fading channel has been a challenging task in the wireless communication era due to the surrounding environment. Therefore, this paper introduces a new technique to e...Accurately characterizing the wireless small-scale fading channel has been a challenging task in the wireless communication era due to the surrounding environment. Therefore, this paper introduces a new technique to experimentally characterize the small-scale fading taking under consideration real environmental conditions. By conducting a two dimensional measurement while the mobile receiver is moving;a more accurate channel will be achieved. Two-dimensional measurement refers to collecting data from the receiver along the x and y direction. The two-dimensional measurement data contain far more information than a one-dimensional data collected. In order to represent the small-scale channel along with the real environmental conditions, new approaches are necessary to configure the two-dimensional system and to analyze the 2D data. The new approach this paper introduces for the characterization is that the measurements are conducted on a receiver while it is moving in a two dimensional manner, under different scenarios, Line-of-sight, Non-line-of-sight, and Two-wave-Diffuse Power. The experiment was conducted in a 7 meters long by 4 meters wide room, wherein the distance between the transmitter antenna and receiver is about 3 meters. Those scenarios represent different real-time conditions where obstacles differ from one scenario to another. For example, the line of sight scenario assumes there a clear line of sight between transmitter and receiver, Non line of sight assumes many obstacles between the transmitter and receiver, i.e. walls, cabinets, etc. and Two Wave Diffuse Power assumes a metallic reflector surrounding the receiver. The experiment showed more accurate results when compared to the one dimensional measurement that has been done in the past where receiver is moving in one direction and also receiver being fixed where a constructive and destructive interference is not captured. The two dimensional measurement technique, i.e. capturing data while receiver moving in both x and y directions, provided ess展开更多
The lack of effective techniques for estimation of shadow power in fading mobile wireless communication channels motivated the use of Kalman Filtering as an effective alternative. In this paper, linear second-order st...The lack of effective techniques for estimation of shadow power in fading mobile wireless communication channels motivated the use of Kalman Filtering as an effective alternative. In this paper, linear second-order state space Kalman Filtering is further investigated and tested for applicability. This is important to optimize estimates of received power signals to improve control of handoffs. Simulation models were used extensively in the initial stage of this research to validate the proposed theory. Recently, we managed to further confirm validation of the concept through experiments supported by data from real scenarios. Our results have shown that the linear second-order state space Kalman Filter (KF) can be more accurate in predicting local shadow power profiles than the first-order Kalman Filter, even in channels with imposed non-Gaussian measurement noise.展开更多
Increased pollution levels have caused damage to our planet. Many scientists are now warning on the long term effects. Green houses gases causes more of the sunlight to be trapped within the Earth’s atmosphere and th...Increased pollution levels have caused damage to our planet. Many scientists are now warning on the long term effects. Green houses gases causes more of the sunlight to be trapped within the Earth’s atmosphere and thus causing increased Earth temperature. Individuals, governments, and private entities are now acting on fixing this problem. One of the most promising solutions is installing an array of solar cells in residential areas. Doing so makes sense for areas with abundant sunlight as the dependency on the grid can be minimized and even completely illuminated while providing a feasible economic perspective at the same time. This paper presents the modelling of a residential setup as a complete system along with an electric vehicle. The modelled components include: Photovoltaic Cells, Home Load Usage, Electric Vehicle, High-Voltage battery as an energy storage, Boost, and Inverter. The presented analysis will help engineers and system designers do better cost analysis. The study can also be used as a basis for maximizing the solar energy usage and perform component optimization.展开更多
A technology called solar energy is a very promising technique, and is considered as the cleanest and the most abundant renewable resource that is naturally available every day. In this paper, a MATLAB environment has...A technology called solar energy is a very promising technique, and is considered as the cleanest and the most abundant renewable resource that is naturally available every day. In this paper, a MATLAB environment has been developed to calculate real-time power incidence on a PV system. It takes into account the time, location, PV tilt, and azimuth angles, and weather conditions to estimate incident power. In this paper, one case study is considered at New York State location. It has been applied to a newly installed 8 kW residential system located in Inwood. The solar panels are made up of silicon HIT (Heterojunction with Intrinsic Thin Layer) cells by Panasonic and solar cell rated at 19%. The result shows that the system is performing at its rated efficiency. The calculations involve the determination of direct, diffused and reflected radiation on the panels taking into account the time of the day, location, PV area, and orientations and weather conditions. The cloudiness index may be estimated based on the weather data and included in the calculations. After performing the irradiance calculations, the output power is estimated based on the rated efficiency at its temperature and compared with the generated output power. The real-time assessment of a PV system performance, during the operational time monitors the health of the PV system. The data obtained by this calculator may accompany production data provided to the consumer by the utility company.展开更多
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 ...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.展开更多
Aim： To assess the changes in semen parameters in men with spinal cord injury （SCI） and the possible causes of these changes. Methods： The study included 45 subjects with SCI. Semen retrieval was done by masturbat...Aim： To assess the changes in semen parameters in men with spinal cord injury （SCI） and the possible causes of these changes. Methods： The study included 45 subjects with SCI. Semen retrieval was done by masturbation （2）, vigorous prostatic massage （n = 13）, penile vibratory stimulation （n = 13） or electroejaculation （n = 17）. Results： The semen of men with SCI showed normal volume （2.3 ± 1.9 mL） and sperm count （85.0 × 10^6 ± 83.8 × 10^6/mE） with decreased motility （11.6% ± 10.1%）, vitality （18.5 % ± 15.2%） and normal forms （17.5 ± 13.4%）, and pus cells has been increased （6.0 × 10^6 ± 8.2 × 10^6/mL）. Total （13.4 ± 9.9 vs. 7.1 ± 6.8） and progressive （4.4 ± 3.9 vs. 2.2 ± 2.1） motility were significantly higher in subjects with lower scrotal temperatures. There was no statistical significant difference between electroejaculation and penile vibratory stimulation groups as regards any of the semen parameters. Subjects＇ age, infrequent ejaculation, injury duration and hormonal profile showed no significant effect on semen parameters. Conclusion： The defining characteristics of the seminogram in men with SCI are normal volume and count with decreased sperm motility, vitality and normal forms, and the increased number of pus cells. The most acceptable cause of the deterioration of semen is elevated scrotal temperature.展开更多
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 (DQP...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).展开更多
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...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.展开更多
The academic community is currently confronting some challenges in terms of analyzing and evaluating the progress of a student’s academic performance. In the real world, classifying the performance of the students is...The academic community is currently confronting some challenges in terms of analyzing and evaluating the progress of a student’s academic performance. In the real world, classifying the performance of the students is a scientifically challenging task. Recently, some studies apply cluster analysis for evaluating the students’ results and utilize statistical techniques to part their score in regard to student’s performance. This approach, however, is not efficient. In this study, we combine two techniques, namely, k-mean and elbow clustering algorithm to evaluate the student’s performance. Based on this combination, the results of performance will be more accurate in analyzing and evaluating the progress of the student’s performance. In this study, the methodology has been implemented to define the diverse fascinating model taking the student test scores.展开更多
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 e...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.展开更多
Smart parking systems are a crucial component of the “smart city” concept, especially in the age of the Internet of Things (IoT). They aim to take the stress out of finding a vacant parking spot in city centers, due...Smart parking systems are a crucial component of the “smart city” concept, especially in the age of the Internet of Things (IoT). They aim to take the stress out of finding a vacant parking spot in city centers, due to the increasing number of cars, especially during peak hours. To realize the concept of smart parking, IoT-enabling technologies must be utilized, as the traditional way of developing smart parking solutions entails a lack of scalability, compatibility with IoT-constrained devices, security, and privacy awareness. In this paper, we propose a secure and privacy-preserving framework for smart parking systems. The framework relies on the publish/subscribe communication model for exchanging a huge volume of data with a large number of clients. On one hand, it provides functional services, including parking vacancy detection, real-time information for drivers about parking availability, driver guidance, and parking reservation. On the other hand, it provides security approaches on both the network and application layers. In addition, it supports mutual authentication mechanisms between entities to ensure device/ data authenticity, and provide security protection for users. That makes our proposed framework resilient to various types of security attacks, such as replay, phishing, and man-in-the-middle attacks. Finally, we analyze the performance of our framework, which is suitable for IoT devices, in terms of computation and network overhead.展开更多
This paper presents a novel and cost effective method to be used in the optimization of the Gaussian Frequency Shift Keying (GFSK) at the receiver of the Bluetooth communication system. The proposed method enhances th...This paper presents a novel and cost effective method to be used in the optimization of the Gaussian Frequency Shift Keying (GFSK) at the receiver of the Bluetooth communication system. The proposed method enhances the performance of the noncoherent demodulation schemes by improving the Bit Error Rate (BER) and Frame Error Rate (FER) outcomes. Linear, Extended, and Unscented Kalman Filters are utilized in this technique. A simulation model, using Simulink, has been created to simulate the Bluetooth voice transmission system with the integrated filters. Results have shown improvements in the BER and FER, and that the Unscented Kalman Filters (UKF) have shown superior performance in comparison to the linear Kalman Filter (KF) and the Extended Kalman Filter (EKF). To the best of our knowledge, this research is the first to propose the usage of the UKF in the optimization of the Bluetooth System receivers in the presence of additive white Gaussian noise (AWGN), as well as interferences.展开更多
Aim： To access beta-endorphin levels in serum as well as seminal plasma in different infertile male groups. Methods： Beta-endorphin was estimated in the serum and seminal plasma by enzyme-linked immunosorbent assay ...Aim： To access beta-endorphin levels in serum as well as seminal plasma in different infertile male groups. Methods： Beta-endorphin was estimated in the serum and seminal plasma by enzyme-linked immunosorbent assay （ELISA） method in 80 infertile men equally divided into four groups： non-obstructive azoospermia （NOA）, obstructive azoospermia （OA）, congenital bilateral absent vas deferens （CBVAD） and asthenozoospermia. The results were compared to those of 20 normozoospermic proven fertile men. Results： There was a decrease in the mean levels of betaendorphin in the seminal plasma of all successive infertile groups （mean ± SD： NOA 51.30 ± 27.37, OA 51.88 ± 9.47, CBAVD 20.36 ± 13.39, asthenozoospermia 49.26 ± 12.49 pg/mL, respectively） compared to the normozoospermic fertile control （87.23 ± 29.55 pg/mL）. This relation was not present in mean serum level of beta-endorphin between four infertile groups （51.09 ± 14.71, 49.76 ± 12.4, 33.96 ± 7.2, 69.1 ± 16.57 pg/mL, respectively） and the fertile control group （49.26 ± 31.32 pg/mL）. The CBVAD group showed the lowest seminal plasma mean level of beta-endorphin. Testicular contribution of seminal beta-endorphin was estimated to be approximately 40%. Seminal beta-endorphin showed significant correlation with the sperm concentration （r = 0.699, P = 0.0188） and nonsignificant correlation with its serum level （r = 0.375, P = 0.185） or with the sperm motility percentage （r = 0.470, P = 0.899）. Conclusion： The estimation of beta-endorphin alone is not conclusive to evaluate male reproduction as there are many other opiates acting at the hypothalamic pituitary gonadal axis.展开更多
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 Co...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.展开更多
Present-day power conversion and conditioning systems focus on transferring energy from a single type of power source into a single type of load or energy storage system (ESS). While these systems can be optimized wit...Present-day power conversion and conditioning systems focus on transferring energy from a single type of power source into a single type of load or energy storage system (ESS). While these systems can be optimized within their specific topology (e.g. MPPT for solar applications and BMS for batteries), the topologies are not easily adapted to accept a wide range of power flow operating conditions. With a hybrid approach to energy storage and power flow, a system can be designed to operate at its most advantageous point, given the operating conditions. Based on the load demand, the system can select the optimal power source and ESS. This paper will investigate the feasibility of combining two types of power sources (main utility grid and photovoltaics (PV)) along with two types of ESS (ultra-capacitors and batteries). The simulation results will show the impact of a hybrid ESS on a grid-tied residential microgrid system performance under various operating scenarios.展开更多
The present study is aimed to serve a small community living on Stand-Alone Solar-Energy (S.A.S.E.S) system. As a basis for the study 1 cubic meter of hydrogen is to be produced by electrolysis in 5 hrs that requires ...The present study is aimed to serve a small community living on Stand-Alone Solar-Energy (S.A.S.E.S) system. As a basis for the study 1 cubic meter of hydrogen is to be produced by electrolysis in 5 hrs that requires energy input of 5 KW-hr. The proposed system consists of the following main components: photovoltaic module, water electrolyzer and fuel cell. Solar hydrogen production by water electrolysis is described and design parameters are specified. Economic feasibility of the proposed system is evaluated. The projected cost of hydrogen is calculated and found to be 5 cents/ft3.展开更多
We present in this paper a method for enhancing equalization of a dynamic channel. A dynamic channel is characterized and modeled by a high relative velocity between transmitter and receiver and fast changes of enviro...We present in this paper a method for enhancing equalization of a dynamic channel. A dynamic channel is characterized and modeled by a high relative velocity between transmitter and receiver and fast changes of environment conditions for wave propagation. Based on Jakes model, an auto-regressive model (AR) [1] for such a dynamic system, i.e., a time variant channel is developed. More specifically, the enhanced equalization method we are proposing is a combination of a multi-stage time and frequency domain equalizer with a feed-forward loop. The underlined wok presents a unified approach to the equalization method that employs both time and frequency domains data to enhance the equalization scheme. In an OFDM system, the channel coefficients for each tap, in time domain for consecutive blocks, are partially independent thus correlated. Such correlation can improve the channel estimation if it is taken into account. The method in this paper enhances the performance of equalization by dynamically selecting the number of previous OFDM symbols based on the Doppler frequency. In order to decrease the complexity of the system model, we utilize the autocorrelation and Doppler frequency to dynamically select the previous OFDM symbols that will be stored in the memory. In addition to deriving earlier results in a unified manner, the approach presented also leads to enhanced performance results without imposing any restrictions or limitations on the OFDM system such as increasing the number of pilots or cyclic prefix.展开更多
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 featur...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.展开更多
文摘Electric Vehicle (EV) adoption is rapidly increasing, necessitating efficient and precise methods for predicting EV charging requirements. The early and precise prediction of the battery discharging status is helpful to avoid the complete discharging of the battery. The complete discharge of the battery degrades its lifetime and requires a longer charging duration. In the present work, a novel approach leverages the Edge Impulse platform for live prediction of the battery status and early alert signal to avoid complete discharging. The proposed method predicts the actual remaining useful life of batteries. A powerful edge computing platform utilizes Tensor Flow-based machine learning models to predict EV charging needs accurately. The proposed method improves the overall lifetime of the battery by the efficient utilization and precise prediction of the battery status. The EON-Tuner and DSP processing blocks are used for efficient results. The performance of the proposed method is analyzed in terms of accuracy, mean square error and other performance parameters.
基金supported by the Deanship of Postgraduate Studies and Scientific Research at Majmaah University in Saudi Arabia under Project Number(ICR-2024-1002).
文摘In the contemporary era,the global expansion of electrical grids is propelled by various renewable energy sources(RESs).Efficient integration of stochastic RESs and optimal power flow(OPF)management are critical for network optimization.This study introduces an innovative solution,the Gaussian Bare-Bones Levy Cheetah Optimizer(GBBLCO),addressing OPF challenges in power generation systems with stochastic RESs.The primary objective is to minimize the total operating costs of RESs,considering four functions:overall operating costs,voltage deviation management,emissions reduction,voltage stability index(VSI)and power loss mitigation.Additionally,a carbon tax is included in the objective function to reduce carbon emissions.Thorough scrutiny,using modified IEEE 30-bus and IEEE 118-bus systems,validates GBBLCO’s superior performance in achieving optimal solutions.Simulation results demonstrate GBBLCO’s efficacy in six optimization scenarios:total cost with valve point effects,total cost with emission and carbon tax,total cost with prohibited operating zones,active power loss optimization,voltage deviation optimization and enhancing voltage stability index(VSI).GBBLCO outperforms conventional techniques in each scenario,showcasing rapid convergence and superior solution quality.Notably,GBBLCO navigates complexities introduced by valve point effects,adapts to environmental constraints,optimizes costs while considering prohibited operating zones,minimizes active power losses,and optimizes voltage deviation by enhancing the voltage stability index(VSI)effectively.This research significantly contributes to advancing OPF,emphasizing GBBLCO’s improved global search capabilities and ability to address challenges related to local minima.GBBLCO emerges as a versatile and robust optimization tool for diverse challenges in power systems,offering a promising solution for the evolving needs of renewable energy-integrated power grids.
文摘Accurately characterizing the wireless small-scale fading channel has been a challenging task in the wireless communication era due to the surrounding environment. Therefore, this paper introduces a new technique to experimentally characterize the small-scale fading taking under consideration real environmental conditions. By conducting a two dimensional measurement while the mobile receiver is moving;a more accurate channel will be achieved. Two-dimensional measurement refers to collecting data from the receiver along the x and y direction. The two-dimensional measurement data contain far more information than a one-dimensional data collected. In order to represent the small-scale channel along with the real environmental conditions, new approaches are necessary to configure the two-dimensional system and to analyze the 2D data. The new approach this paper introduces for the characterization is that the measurements are conducted on a receiver while it is moving in a two dimensional manner, under different scenarios, Line-of-sight, Non-line-of-sight, and Two-wave-Diffuse Power. The experiment was conducted in a 7 meters long by 4 meters wide room, wherein the distance between the transmitter antenna and receiver is about 3 meters. Those scenarios represent different real-time conditions where obstacles differ from one scenario to another. For example, the line of sight scenario assumes there a clear line of sight between transmitter and receiver, Non line of sight assumes many obstacles between the transmitter and receiver, i.e. walls, cabinets, etc. and Two Wave Diffuse Power assumes a metallic reflector surrounding the receiver. The experiment showed more accurate results when compared to the one dimensional measurement that has been done in the past where receiver is moving in one direction and also receiver being fixed where a constructive and destructive interference is not captured. The two dimensional measurement technique, i.e. capturing data while receiver moving in both x and y directions, provided ess
文摘The lack of effective techniques for estimation of shadow power in fading mobile wireless communication channels motivated the use of Kalman Filtering as an effective alternative. In this paper, linear second-order state space Kalman Filtering is further investigated and tested for applicability. This is important to optimize estimates of received power signals to improve control of handoffs. Simulation models were used extensively in the initial stage of this research to validate the proposed theory. Recently, we managed to further confirm validation of the concept through experiments supported by data from real scenarios. Our results have shown that the linear second-order state space Kalman Filter (KF) can be more accurate in predicting local shadow power profiles than the first-order Kalman Filter, even in channels with imposed non-Gaussian measurement noise.
文摘Increased pollution levels have caused damage to our planet. Many scientists are now warning on the long term effects. Green houses gases causes more of the sunlight to be trapped within the Earth’s atmosphere and thus causing increased Earth temperature. Individuals, governments, and private entities are now acting on fixing this problem. One of the most promising solutions is installing an array of solar cells in residential areas. Doing so makes sense for areas with abundant sunlight as the dependency on the grid can be minimized and even completely illuminated while providing a feasible economic perspective at the same time. This paper presents the modelling of a residential setup as a complete system along with an electric vehicle. The modelled components include: Photovoltaic Cells, Home Load Usage, Electric Vehicle, High-Voltage battery as an energy storage, Boost, and Inverter. The presented analysis will help engineers and system designers do better cost analysis. The study can also be used as a basis for maximizing the solar energy usage and perform component optimization.
文摘A technology called solar energy is a very promising technique, and is considered as the cleanest and the most abundant renewable resource that is naturally available every day. In this paper, a MATLAB environment has been developed to calculate real-time power incidence on a PV system. It takes into account the time, location, PV tilt, and azimuth angles, and weather conditions to estimate incident power. In this paper, one case study is considered at New York State location. It has been applied to a newly installed 8 kW residential system located in Inwood. The solar panels are made up of silicon HIT (Heterojunction with Intrinsic Thin Layer) cells by Panasonic and solar cell rated at 19%. The result shows that the system is performing at its rated efficiency. The calculations involve the determination of direct, diffused and reflected radiation on the panels taking into account the time of the day, location, PV area, and orientations and weather conditions. The cloudiness index may be estimated based on the weather data and included in the calculations. After performing the irradiance calculations, the output power is estimated based on the rated efficiency at its temperature and compared with the generated output power. The real-time assessment of a PV system performance, during the operational time monitors the health of the PV system. The data obtained by this calculator may accompany production data provided to the consumer by the utility company.
文摘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.
文摘Aim： To assess the changes in semen parameters in men with spinal cord injury （SCI） and the possible causes of these changes. Methods： The study included 45 subjects with SCI. Semen retrieval was done by masturbation （2）, vigorous prostatic massage （n = 13）, penile vibratory stimulation （n = 13） or electroejaculation （n = 17）. Results： The semen of men with SCI showed normal volume （2.3 ± 1.9 mL） and sperm count （85.0 × 10^6 ± 83.8 × 10^6/mE） with decreased motility （11.6% ± 10.1%）, vitality （18.5 % ± 15.2%） and normal forms （17.5 ± 13.4%）, and pus cells has been increased （6.0 × 10^6 ± 8.2 × 10^6/mL）. Total （13.4 ± 9.9 vs. 7.1 ± 6.8） and progressive （4.4 ± 3.9 vs. 2.2 ± 2.1） motility were significantly higher in subjects with lower scrotal temperatures. There was no statistical significant difference between electroejaculation and penile vibratory stimulation groups as regards any of the semen parameters. Subjects＇ age, infrequent ejaculation, injury duration and hormonal profile showed no significant effect on semen parameters. Conclusion： The defining characteristics of the seminogram in men with SCI are normal volume and count with decreased sperm motility, vitality and normal forms, and the increased number of pus cells. The most acceptable cause of the deterioration of semen is elevated scrotal temperature.
文摘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).
文摘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.
文摘The academic community is currently confronting some challenges in terms of analyzing and evaluating the progress of a student’s academic performance. In the real world, classifying the performance of the students is a scientifically challenging task. Recently, some studies apply cluster analysis for evaluating the students’ results and utilize statistical techniques to part their score in regard to student’s performance. This approach, however, is not efficient. In this study, we combine two techniques, namely, k-mean and elbow clustering algorithm to evaluate the student’s performance. Based on this combination, the results of performance will be more accurate in analyzing and evaluating the progress of the student’s performance. In this study, the methodology has been implemented to define the diverse fascinating model taking the student test scores.
文摘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.
文摘Smart parking systems are a crucial component of the “smart city” concept, especially in the age of the Internet of Things (IoT). They aim to take the stress out of finding a vacant parking spot in city centers, due to the increasing number of cars, especially during peak hours. To realize the concept of smart parking, IoT-enabling technologies must be utilized, as the traditional way of developing smart parking solutions entails a lack of scalability, compatibility with IoT-constrained devices, security, and privacy awareness. In this paper, we propose a secure and privacy-preserving framework for smart parking systems. The framework relies on the publish/subscribe communication model for exchanging a huge volume of data with a large number of clients. On one hand, it provides functional services, including parking vacancy detection, real-time information for drivers about parking availability, driver guidance, and parking reservation. On the other hand, it provides security approaches on both the network and application layers. In addition, it supports mutual authentication mechanisms between entities to ensure device/ data authenticity, and provide security protection for users. That makes our proposed framework resilient to various types of security attacks, such as replay, phishing, and man-in-the-middle attacks. Finally, we analyze the performance of our framework, which is suitable for IoT devices, in terms of computation and network overhead.
文摘This paper presents a novel and cost effective method to be used in the optimization of the Gaussian Frequency Shift Keying (GFSK) at the receiver of the Bluetooth communication system. The proposed method enhances the performance of the noncoherent demodulation schemes by improving the Bit Error Rate (BER) and Frame Error Rate (FER) outcomes. Linear, Extended, and Unscented Kalman Filters are utilized in this technique. A simulation model, using Simulink, has been created to simulate the Bluetooth voice transmission system with the integrated filters. Results have shown improvements in the BER and FER, and that the Unscented Kalman Filters (UKF) have shown superior performance in comparison to the linear Kalman Filter (KF) and the Extended Kalman Filter (EKF). To the best of our knowledge, this research is the first to propose the usage of the UKF in the optimization of the Bluetooth System receivers in the presence of additive white Gaussian noise (AWGN), as well as interferences.
文摘Aim： To access beta-endorphin levels in serum as well as seminal plasma in different infertile male groups. Methods： Beta-endorphin was estimated in the serum and seminal plasma by enzyme-linked immunosorbent assay （ELISA） method in 80 infertile men equally divided into four groups： non-obstructive azoospermia （NOA）, obstructive azoospermia （OA）, congenital bilateral absent vas deferens （CBVAD） and asthenozoospermia. The results were compared to those of 20 normozoospermic proven fertile men. Results： There was a decrease in the mean levels of betaendorphin in the seminal plasma of all successive infertile groups （mean ± SD： NOA 51.30 ± 27.37, OA 51.88 ± 9.47, CBAVD 20.36 ± 13.39, asthenozoospermia 49.26 ± 12.49 pg/mL, respectively） compared to the normozoospermic fertile control （87.23 ± 29.55 pg/mL）. This relation was not present in mean serum level of beta-endorphin between four infertile groups （51.09 ± 14.71, 49.76 ± 12.4, 33.96 ± 7.2, 69.1 ± 16.57 pg/mL, respectively） and the fertile control group （49.26 ± 31.32 pg/mL）. The CBVAD group showed the lowest seminal plasma mean level of beta-endorphin. Testicular contribution of seminal beta-endorphin was estimated to be approximately 40%. Seminal beta-endorphin showed significant correlation with the sperm concentration （r = 0.699, P = 0.0188） and nonsignificant correlation with its serum level （r = 0.375, P = 0.185） or with the sperm motility percentage （r = 0.470, P = 0.899）. Conclusion： The estimation of beta-endorphin alone is not conclusive to evaluate male reproduction as there are many other opiates acting at the hypothalamic pituitary gonadal axis.
文摘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.
文摘Present-day power conversion and conditioning systems focus on transferring energy from a single type of power source into a single type of load or energy storage system (ESS). While these systems can be optimized within their specific topology (e.g. MPPT for solar applications and BMS for batteries), the topologies are not easily adapted to accept a wide range of power flow operating conditions. With a hybrid approach to energy storage and power flow, a system can be designed to operate at its most advantageous point, given the operating conditions. Based on the load demand, the system can select the optimal power source and ESS. This paper will investigate the feasibility of combining two types of power sources (main utility grid and photovoltaics (PV)) along with two types of ESS (ultra-capacitors and batteries). The simulation results will show the impact of a hybrid ESS on a grid-tied residential microgrid system performance under various operating scenarios.
文摘The present study is aimed to serve a small community living on Stand-Alone Solar-Energy (S.A.S.E.S) system. As a basis for the study 1 cubic meter of hydrogen is to be produced by electrolysis in 5 hrs that requires energy input of 5 KW-hr. The proposed system consists of the following main components: photovoltaic module, water electrolyzer and fuel cell. Solar hydrogen production by water electrolysis is described and design parameters are specified. Economic feasibility of the proposed system is evaluated. The projected cost of hydrogen is calculated and found to be 5 cents/ft3.
文摘We present in this paper a method for enhancing equalization of a dynamic channel. A dynamic channel is characterized and modeled by a high relative velocity between transmitter and receiver and fast changes of environment conditions for wave propagation. Based on Jakes model, an auto-regressive model (AR) [1] for such a dynamic system, i.e., a time variant channel is developed. More specifically, the enhanced equalization method we are proposing is a combination of a multi-stage time and frequency domain equalizer with a feed-forward loop. The underlined wok presents a unified approach to the equalization method that employs both time and frequency domains data to enhance the equalization scheme. In an OFDM system, the channel coefficients for each tap, in time domain for consecutive blocks, are partially independent thus correlated. Such correlation can improve the channel estimation if it is taken into account. The method in this paper enhances the performance of equalization by dynamically selecting the number of previous OFDM symbols based on the Doppler frequency. In order to decrease the complexity of the system model, we utilize the autocorrelation and Doppler frequency to dynamically select the previous OFDM symbols that will be stored in the memory. In addition to deriving earlier results in a unified manner, the approach presented also leads to enhanced performance results without imposing any restrictions or limitations on the OFDM system such as increasing the number of pilots or cyclic prefix.
文摘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.
