Engineering and Technology Journal

The traditional concepts and practices of power systems are superimposed by economic market management. So OPF has become complex, and classical optimization methods were used to solve OPF effectively. But, in recent years, Artificial Intelligence methods (GA, etc.) have emerged that can solve highly complex OPF problems. In this work two algorithms, were used for the solution of dynamic optimal power flow (OPF) problem taking the transmission losses and the cost of generation as the main constraints. Both algorithms were tested on a 14-bus IEEE test system. The contingency analysis was considered in the application of the algorithms. Additionally, a comparison was made between the two algorithms. The obtained results showed the effectiveness of the GA algorithm over the traditional algorithm

Microprocessor programming algorithms in electrical inverter drive systems are essential in developing and formulating modern methods in closed control circuits. The microprocessor used in the current research, TMS320f28335, has a high system clock s frequency (150 MHz) that reaches up to, which gives an almost perfect ability to output the three-voltage sinewave generated from the inverter under consideration. Obtaining a sinewave voltage means the lowest possible harmonics (THD) and thus the best performance of the induction motor at starting and dynamic stability. The current research used the directional inclusion method to implement the six inverter switches (IGBTs) mechanism. Mathematical calculations were made for Space Vector Pulse Width Modulation (SVPWM) method, and then the microprocessor was programmed to implement it. The practical board Voltage Source inverter (VSI) was tested extensively.

Hyperbolic tangents and Sigmoid are commonly used for Artificial Neural Networks as activation functions. The complex equation of the activation function is one of the most difficult to be implemented in hardware because containing division and exponential, which gives non-linear behavior. The challenge is building a tan-sigmoid function in hardware with efficient performance. Therefore, this work will focus on implementing the activation function in FPGA. To overcome this challenge, a different approach was proposed in this paper, efficient hardware-implemented for tan-sigmoid in terms of the number of slices occupied and the resources utilization are designed. In this work, three approaches
are proposed: tan-sigmoid using the log approximation method, tan-sigmoid using
segmentation method, and tan-sigmoid using the polynomial method. These
approaches are efficiently implemented in the Xilinx Spartan-3A xc3s700a-4fg484
platform. Hardware synthesis and FPGA implementations illustrate that the
proposed tan-sigmoid only takes up to 1% of logic resources in the first and second
proposed approaches. While, 4% showed in the third proposed approach, with the
best efficiency and significantly confirmed the lowest implementation costs than
the traditional approach.

The studies on brain tumor detection and classification are continuing to improve the specialists’ ability in diagnosis. Magnetic Resonance Imaging (MRI) is one of the most common techniques used to evaluate brain tumors diagnosis. However, brain tumors diagnosis is a difficult process due to congenital malformations and possible errors in diagnosing benign from malignant tumors. Therefore, this research aims to propose an integrated algorithm to classify brain tumors following two stages using the Kernel Support Vector Machine (KSVM) classifier. First stage classifies the tumors as normal and abnormal, and the second classifies abnormal tumors as benign and malignant. The first KSVM employs extraction features by considering the pixel values to classify images as a shape. In contrast, the second KSVM uses the Discrete Wavelet Transform (DWT), followed by the Principal Component Analysis (PCA) technique to extract and reduce features and improve the model performance. Also, K-means clustering algorithm is used to segment, isolate and calculate the tumor area. The KSVM classifiers use two kernels (linear and Radial Basis Function (RBF)). Obtained results showed that the linear kernel achieved 97.5% accuracy and 98.57% accuracy in the first and second classifier, respectively. For all linear classifiers, a 100% sensitivity level is achieved. This work validates the proposed model based on the (K-fold) strategy.

In this study, thin films of pure iron oxide (Fe3O4) were prepared using pulsed laser deposition technique under vacuum (2×10-3 mbar) using Nd: YAG laser at different laser energies (700, 800, 900, and 1000 mJ) on quartz slides at the substrate temperature of 200 °C with different thickness (170, 190, 220, and 250 nm). The prepared thin films were examined using different techniques. The X-ray diffraction showed a polycrystalline structure of cubic Fe3O4 phase, enhanced its crystallinity, and increased the crystalline size when increasing the laser energy to 1000 mJ. The results revealed that high transparency samples decreased pulse laser energy. As the laser pulse power increases, the transparency decreases from 91% to 61%, where optical properties deteriorate significantly. The bandgap values were detected to be 3.9 eV, 3.75 eV, 3.21 eV, and 3 eV when the laser energies were increased with thickness (170–250) nm. In addition, the extinction coefficient, dielectric constants, optical constants, and refractive constants were studied.

In this work, the effects of pumping profiles on the temperature distributions in solid-state lasers pumped by laser diode from two different end faces were studied. With different pump spot radii of 0.4???????????????? ???????????????????????? 0.6????????????????, various exponent factors were examined to evaluate the behavior of temperature distributions due to Gaussian and super-Gaussian profiles. For a Gaussian pumping (n=2), the maximum temperature difference on each rod face was calculated to be 295.5 K and 226 K, respectively, at a total pump power of 92.8 W (46.4 W per face). While at the same pumping power, the temperature decreased as the n exponent increased. A good match was obtained between the proposed model and the previous works listed in the literature.

The effect of telescope losses (TL) on wideband wavelength division multiplexing (Wideband-WDM) based on free-space optical communication (FSOC) is investigated via OptiSystem software. In this work, both single and dual channel FSOC systems are investigated under different communication weathers: clear, haze, rain, and fog with attenuation losses of 0.2 dB/km, 2.3 dB/km, 4.3 dB/km, and 8.0 dB/km, respectively. The TL measures the coupling efficiency between the fiber and telescope in the transceiver assembly; therefore, is considered an important design parameter for the FSOC and hybrid optical communication system. According to the results, the maximum TL is 23 dB and 29 dB for single and dual FSOC, respectively, at the clear weather condition and for 1 km communication distance. This means that the dual-channel system could afford higher losses than the single system by approximately 26.1 %. Furthermore, this ratio is approximately the same for the other weather conditions, 28.6 %, 31.6 %, and 40 % for the hazy, rain, and fog weather, respectively.

The bearingless BLDC motor gathers all advantages of the BLDC motor and bearingless machine, and this motor is extensively used in blood and artificial heart pumps. In a bearingless BLDC motor, there are two sets of windings, the main winding, responsible for producing the motor torque, and the suspension winding, which keeps the rotor in the center without any contact with the stator. Generally, the suspension system is responsible for the generation of the suspension forces to cancel the pull-out forces (radial forces), which strongly depends on the accurate evaluation of radial forces distribution at different operating conditions. In this paper, a mathematical model based on the finite element method is used to calculate and analyze the radial force of a bearingless blood pump BLDC motor using Ansys/Maxwell. Based on Maxwell equations, the normal and tangential components of the airgap flux density is determined and used to calculate the radial force, magnitude, and direction. In addition, different cases of rotor displacement under eccentricity conditions are covered. The relation between the rotor displacement and radial force is analyzed, accounting for the displacement direction. Finally, the results are analyzed and discussed.

The biggest challenge in the solar system is to extract the maximum output power from photovoltaic (PV) panels under different solar radiation and temperature conditions. This paper presents a comparative study between perturb and observe (P & O) and incremental conduction (INC) algorithms. These are the most popular algorithms for tracking solar PV panels and extracting the maximum power point (MPP) under different climate conditions. The studied PV system and the MPPT techniques have been investigated by simulation using MATLAB/Simulink. The simulation includes a boost converter, which increases the PV panel voltage by controlling the duty cycle. The obtained results show that the P & O performance close to MPP under constant test conditions (STC) is better than the variable conditions due to oscillation. In contrast, the performance of the INC algorithm is better than P & O in terms of speed to reach MPP, accuracy, and quality under changes in radiation and temperature conditions.

This paper presents software defining network SDN control in wireless sensor networks (WSN) to estimate packet flow, which relies on a Gaussian filter to filter the transmitted signal. The practical aim of this method is to predict the next step of packet flow earlier, which helps reduce congestion if it occurs. The proposed model (SDN-WSN with Gaussian filter) is applied to enhance signal transmission, reduce data error, reduce congestion network and reduce data overflow data. The methodology of the proposed work can be explained as follows: first: distributing nodes randomly; second: Applying the K-mean cluster to choose to select the optimum position of the head cluster node; third: connecting the network using LEACH protocol. Moreover. In this work, SDN with a Gaussian filter is proposed to control the network and minimize data error. It is possible to achieve that by adding buffer memory for each node to store data. The data transmission process is controlled by SDN, and a Gaussian filter is applied before transmitting data to minimize error data. The proposed method's simulation results proved its effectiveness in prolonging the network lifetime by nearly more than 30% rounds than out-of-date WSN, reducing the average density of memory to 20% than out-of-date WSN, and increasing the average capacitance of memory to 20% than out-of-date WSN.

The study presents circuitry modeling and methodology to integrate solar photovoltaic (PV) energy with grid (AC) sources to supplement household appliances during a power cut-off or restricted supply period and alternating charge deep cycle batteries. This paper discusses an FPGA-based Sinusoidal Pulse Width Modulation (SPWM) generator as a control mechanism for a PV/Battery full-bridge inverter. The inverter's efficacy is expressed as the Total Harmonic Distortion (THD) ratio, which must be as low as possible. Various schemes are proposed to reduce THD to generate a more sinusoidal output wave. SPWM is mostly used in industrial inverters. Two SPWM techniques, Bipolar and unipolar, are compared under a variety of Modulation Index (MI) conditions and Carrier Frequency (fc) to analyze the best performance of the full-bridge inverter with less (THD) and smoother output sinewave. The present paper discusses the results of a simulation for a single-phase full-bridge inverter employing bipolar and unipolar SPWM techniques. The output waveform demonstrates that the Unipolar SPWM technique produces less Total harmonic Distortion than the Bipolar method, with THD 45% lower. ISE 14.7 and Matlab 2019 are used to present, simulate SPWM generating code, and implement the design on a field-programmable gate array (FPGA), which acts as a controller for the Mosfet gates in the full-bridge inverter to constitute a sine wave without changing any hardware configuration in the circuit design. The system implementation of SPWM Pulse generation has been validated on Xilinx Spartan 6 FPGA (XC6SLX45) board using VHDL code. The final test on the system design for the SPWM generation program, after synthesis and compilation were finalized and verified on a prototype system.

The era of the wireless communication-based indoor environment has resulted in several challenges represented by signal reflection, diffraction, and attenuation. Thereby, it affects several wireless-based applications such as positioning, localization, monitoring different objects. With such challenges, estimation error would be increased significantly, and the accuracy will be reduced. To handle such challenges, several new approaches were proposed by many researchers. The most interesting approach for the localization purpose was the hybrid localization approach. A combination of several parameters would be utilized to propose methods that take advantage of these parameters. In this work, a comprehensive analysis was carried out for results obtained based on the proposition of two hybrid algorithms for localization in an indoor environment. The first algorithm utilized the Received Signal Strength (RSS) and Angle of Arrival (AoA) parameter to be tested for both Omni and Directional antenna type Access point (AP) device. While the second algorithm was based on the use of Time of Arrival (ToA) and RSS, which have been calculated via Wireless InSite (WI) software. The analyzing results indicate that using AoA/RSS method with the Omni AP antenna has achieved higher accuracy for the overall normal distribution scenario. However, ToA/RSS has shown higher accuracy estimation for far point distribution. Meanwhile, AoA/RSS with Directional antenna AP has an accuracy limited with distribution location. Due to the characteristics of the directional antenna pattern.

GaN nanostructure was Synthesized using Pulsed laser ablation in liquid ethanol with Nd:YAG laser at pulsed laser ablation energy of 1600 mj and laser wavelength of 1064 nm. The nanoparticle was deposited using the drop cast method on the prepared porous silicon substrate. The structural and optical properties of the prepared GaN were studied. XRD pattern shows a high and sharp peak of pSi peak at 2θ =28.74 reflected from (111) plane and exhibits h-GaN rise at 2θ =34.54, 2θ =37.49, 2θ= 48.19 and 2θ=57.99 which are reflected from (002), (100), (102), (110) planes respectively where (002) plane has the highest peak than others. AFM and FESM proved an increase in the grain size of GaN. The reflectance of GaN (81.79%) at the wavelength (306nm) and has an energy band gap of (3.9eV).

Cascaded optical fiber single mode-no core-single mode fiber (SNS) attracted attention for being the base of various photonic devices. These devices are used in optical communication, fiber sensors, and fiber laser technology. The effect of variable NCF specifications, length, diameter, external refractive index (ERI), propagating wavelength on the self-imaging position, and the multimode interference (MMI) is studied. The study aims to simulate and analyze cascaded optical fiber by using the finite element beam envelope method (BEM). To the best of our knowledge, this is the first report that studied the self-imaging in cascaded optical fiber longitudinally by using BEM. The NCF length is important in determining the coupled out intensity and peak transmission wavelength. The field in the cascaded fiber is simulated for single and multi-wavelengths to evaluate the maximum transmission and study the structure's tunability. A tunable filter is simulated, where varying the length of the NCF about 0.6 mm produces a wavelength shift of about 40 nm. The BEM is effective in studying the field propagation in large guiding photonic devices.

In this paper, the effect of using laser ablation of pure gold targets to obtain gold Nano rods and for pure zinc targets to obtain zinc oxide nanoparticles was studied separately in ethanol using an Nd:YAG laser tattoo removal (nanosecond pulses) and then mixing the resulting mixtures to obtain gold dopant with zinc oxide. Transmission electron microscopy (TEM), (XRD) X-Ray Diffraction and the optical properties were used to characterize the pure gold Nano rods, ZnO nanoparticles, and Au doped ZnO nanoparticles. Based on XRD and TEM, the results revealed the properties of the produced gold Nano roads. The obtained results indicated that the gold Nano rods produced by the 1064nm laser have superior optical, structural, and morphological properties and can be used in different sensors.

In this work, two different configurations of hybrid fiber optic amplifiers are investigated and simulated via OptiSystem 7.0 software, namely, serial and parallel hybrid fiber optical amplifiers (S– and P–HFOAs). The investigation involves performance comparison for the S– and P–HFOA under optimum pump conditions to demonstrate the advantages and disadvantages of each configuration. The simulation results show that the serial configuration has a high average gain level of 19.2 dB, an appropriate noise figure about 4.3 dB, but low saturation power, and limited gain bandwidth of approximately 40 nm, which is considered a primary issue in S–HOFA design, in addition to the pump conversion efficiency still insufficient in the Raman amplifier stage. While in P–HFOA design, a wide
3–dB gain bandwidth of more than 60 nm is maintained, along with an average
gain level of 13.5 dB, high average noise figure about 8.3 dB and high saturation
power due to the absent of cascading effect in parallel configuration.