Fouad Omari; Boutaina Benhmimou; Nancy Gupta; Khalid El Khadiri; Niamat Hussain; Rachid Ahl Laamara; Mohamed El Bakkali
Abstract
CubeSats are a developing disruptive technology with a broad range of applications, including moon missions supplied by some international space agencies. They have motivated the scientific community to focus on this sector with various technologies aimed to be more suitable for advanced CubeSat and ...
Read More
CubeSats are a developing disruptive technology with a broad range of applications, including moon missions supplied by some international space agencies. They have motivated the scientific community to focus on this sector with various technologies aimed to be more suitable for advanced CubeSat and deep space missions. These CubeSat capabilities can be enhanced by designing a suitable new antenna design, which has the potential to significantly reduce manufacturing costs and energy consumption. This research investigates how to develop Fabry-Perot antenna designs and their use for advanced CubeSat missions. In order to identify the best CubeSat application for each design examined in this work, tens of Fabry-Perot antenna designs put forth by the scientific community are evaluated for their geometrical, mechanical, and electrical appropriateness for an advanced CubeSat mission. This study provides comprehensive data to examine the current status of Fabry-Perot antennas and if they are suitable for CubeSats. Furthermore, we offer a collection of design-based analytical models that could be applied to various upcoming advanced CubeSat projects at academic institutions or in collaboration with private or national space agencies.
Ghazanfar Shahgholian; Ehsan Hosseini; Fatemeh Mohammadzamani
Abstract
The penetration of renewable power production units in electrical networks through power electronic converters due to their low rotating inertia, leads to increased frequency fluctuations and reduced power system stability. The synchronization of the power converters with the main network is of great ...
Read More
The penetration of renewable power production units in electrical networks through power electronic converters due to their low rotating inertia, leads to increased frequency fluctuations and reduced power system stability. The synchronization of the power converters with the main network is of great importance, so that it must be maintained even during disturbances. Virtual synchronous machines are among the efficient methods to comply with the scarcity of inertia in the power network. In this paper, the aim is to investigate the stability and simulate the dynamic behavior of connecting a virtual synchronous generator (VSG) to an infinite bus employing a small-signal representative. The characteristics of the VSG are compared with the droop method for controlling active and reactive powers. An evaluation between these two different control strategies has been carried out using simulation results in the MATLAB environment. Also, the attributes of the synchronous machines due to changes in the point of damping and inertia parameters are shown. For the accuracy of the simulation results, the small signal model of the studied system has also been implemented in MATLAB/Simulink. Integrating the VSG in the microgrid, in addition to reducing frequency and voltage deviations, also improves stability.
Guo Li. Ng; Jagadheswaran Rajendran; Selvakumar Mariappan; Norhamizah Idros; Asrulnizam Abdul. Manaf; Narendra Kumar; Arokia Nathan
Abstract
A 65nm CMOS trimmable bandgap reference (BGR) circuit is developed to deliver stable reference voltages of 0.65V, with a supply voltage range of 1.5V to 3.6V. A key contribution is the incorporation of a 16-level 4-bit digital trimming circuit, allowing fine adjustment of the reference voltage. The trimming ...
Read More
A 65nm CMOS trimmable bandgap reference (BGR) circuit is developed to deliver stable reference voltages of 0.65V, with a supply voltage range of 1.5V to 3.6V. A key contribution is the incorporation of a 16-level 4-bit digital trimming circuit, allowing fine adjustment of the reference voltage. The trimming circuit employs a decoder and multiplexer structure to select different points along a resistor ladder, enabling post-manufacturing voltage tuning to compensate for process variations. This methodology ensures precise control of the output voltage, improving accuracy and reliability under varying conditions. The design aims to achieve a phase margin greater than 45°, a temperature coefficient below 2.5mV, and low current consumption under 6µA across Process, Voltage & Temperature (PVT) variations. The workflow includes calculating MOSFET and passive component parameters, designing the schematic of a single-stage operational amplifier and the trimmable BGR circuit, followed by pre-layout simulations. The pre-layout results show a DC gain of 60.88dB and a phase margin of 63° for the op-amp. The temperature coefficient for the 0.65V reference voltage trimmable BGR is 1.67mV across Process, Voltage & Temperature (PVT), with current consumption remaining below 6µA. Considering the degraded circuit performance caused by the process & manufacturing deviation, the addition of the trimming circuit significantly enhances the design's adaptability, ensuring it meets the performance targets even in the presence of manufacturing variations which allow us trim the affected output voltage back to desired voltage where in this work we set it at 0.65V.
Sunpreet Kaur Nanda; Deepika Ghai; Prashant Ingole; Sandeep Kumar; Suman Lata Tripathi
Abstract
Video forensics includes understanding how to examine and identify crime in the footage. The process is constantly evolving with new technology and innovations. The world of video forensics experts is growing. The realm of video forensics is simply a growing community of specialists linked with the digital ...
Read More
Video forensics includes understanding how to examine and identify crime in the footage. The process is constantly evolving with new technology and innovations. The world of video forensics experts is growing. The realm of video forensics is simply a growing community of specialists linked with the digital video forensics sector. The State-of-the-art examinations and crimes consistently cross global and language fringes these days. With rapidly advancing technology, video has emerged as the foremost and indispensable tool in the fight against those who break the law, capturing them in the act. The computerized video forensics industry is rapidly expanding. Rapid technological advancements have made video a powerful and essential tool for law enforcement. Technology changes quickly, and innovators work with computerized images to catch criminals. Video forensics examination helps to know how accurate the input video is. In this paper, the proposed method used a soft computing technique, i.e. YOLOv3, to detect suspicious persons, the guns, or the masks by extracting frames and features from a video. In the dataset, it compares the extracted edge with images and generates output with bounding boxes for suspicious persons, the guns, or the masks. The realm of video forensics and its outcomes are also examined by this paper. When tested on different datasets, the proposed method outperforms existing techniques. For both the models, such as YOLO and customized Convolutional Neural Network (CNN), execution measurements were taken and are shown to supersede the customized CNN with its identification of guns and masks. The accuracy for YOLO design is 100% for both guns and mask detection, respectively, whereas accuracy for the customized CNN with guns and mask detection is 61.54% and 61.55%, respectively. Experimental results show that the proposed methodology outperforms the other existing methods.
Damilare O. Akande; James S. Osunniyi; Zacheaus K. Adeyemo; Ayobami. O. Fawole
Abstract
Wireless Mesh Networks (WMNs) offer a promising approach to pervasive communication with efficient network coverage using minimal infrastructure. However, current WMN routing protocols are inefficient due to high energy consumption. This is caused by limited battery life of nodes, uneven distribution ...
Read More
Wireless Mesh Networks (WMNs) offer a promising approach to pervasive communication with efficient network coverage using minimal infrastructure. However, current WMN routing protocols are inefficient due to high energy consumption. This is caused by limited battery life of nodes, uneven distribution of traffic (load imbalance), and long data transmission distances, all of which shorten network lifetime. This paper proposes a new routing protocol for WMNs called Modified Chicken Swarm Optimization-based Efficient Cluster Head Selection (MCSO-ECHS). MCSO-ECHS leverages the network gateway to select optimal Cluster Heads (CHs). An objective function, considering both residual energy and node distance, is used for CH selection. The MCSO algorithm then refines the selection process to ensure balanced energy consumption among these energy-constrained nodes. This approach prolongs the network lifetime and improves overall energy efficiency. Simulation results demonstrate that MCSO-ECHS outperforms existing protocols in terms of energy consumption, network lifetime, throughput, end-to-end delay and packet delivery ratio, significantly enhancing the energy efficiency of WMNs.
Muhammad Aliff Hafeez Bin Azman; Sim Yi Sy Yi; Kah Haw Law; Mohd Abdul Talib Mat Yusoh; Md Nor Ramdon Bin Baharom; Alvin John Lim Meng Siang; Nur Sabrina Binti Azli Murzami; Khalid Aboubakr Hasan Mousay
Abstract
Global energy use is rising yearly, resulting in a higher demand. Power plants must generate more electricity, thereby placing significant stress on the electrical grid. Solar engineering is a promising solution to this challenge. However, traditional silicon-based solar cells face inherent limitations. ...
Read More
Global energy use is rising yearly, resulting in a higher demand. Power plants must generate more electricity, thereby placing significant stress on the electrical grid. Solar engineering is a promising solution to this challenge. However, traditional silicon-based solar cells face inherent limitations. These cells rely on a single material, which restricts their power conversion efficiency by only capturing a very specific range of the sunlight spectrum.This study explores a novel concept in solar cell design that utilizes a multijunction approach, employing various semiconductor materials to create multiple p-n junctions within the cells. By strategically arranging these materials according to their energy bandgaps, the aim is to maximize the capture of the sunlight spectrum for enhanced power conversion and energy output, ultimately improving efficiency. The research was conducted using MATLAB software to focus on mathematical modeling. By analyzing designs from single junctions up to quintuple junctions and utilizing materials such as Germanium Sulfide, Gallium Arsenide, and Germanium, the study revealed that increasing the number of material layers significantly enhanced the performance of the solar cells. Notably, the quintuple junction solar cell demonstrated the highest efficiency, achieving 26.87% more efficiency compared to single junction cells, which recorded an efficiency of 42.63%.
)
