Showing 241 results for Im
Nurul Syahirah Mohd Ideris, Hasimah Ali, Mohd Shuhanaz Zanar Azalan, Tengku Sarah Tengku Amran,
Volume 21, Issue 2 (6-2025)
Abstract
GPR (Ground Penetrating Radar) is well-known as an effective non-invasive imaging approach for shallow nature underground discovery, like finding and locating submerged objects. Although GPR has achieved some success, it is difficult to automatically process GPR images because human experts must interpret GPR images of buried objects. This can happen due to the possibility of a variety of mediums or underground noises from the environment, especially rocks and roots of trees. Thus, detecting hyperbolic echo characteristics is critical. As a result, Viola Jones detection is used to determine whether the presence of a hyperbolic signature underground indicates a pipe or not. GPR can also be used in the public works department because it is a non-destructive tool. Workers, for example, should be aware of the pipe size that must be replaced when it leaks. The original GPR image already shows hyperbolic image distortion due to pipe refraction. The current method is unreliable due to its lack of flexibility. As a result, there is another method for resolving this issue. Thus, the image will be pre-processed to eliminate or reduce background noise in the GPR input image. The results of this project demonstrate that the Viola Jones algorithm can accurately detect hyperbolic patterns in GPR images.
Mohamad Haniff Junos, Anis Salwa Mohd Khairuddin, Elmi Abu Bakar, Ahmad Faizul Hawary,
Volume 21, Issue 2 (6-2025)
Abstract
Vehicle detection in satellite images is a challenging task due to the variability in scale and resolution, complex background, and variability in object appearance. One-stage detection models are currently state-of-the-art in object detection due to their faster detection times. However, these models have complex architectures that require powerful processing units to train while generating a large number of parameters and achieving slow detection speed on embedded devices. To solve these problems, this work proposes an enhanced lightweight object detection model based on the YOLOv4 Tiny model. The proposed model incorporates multiple modifications, including integrating a Mix-efficient layer aggregation network within its backbone network to optimize efficiency by reducing parameter generation. Additionally, an improved small efficient layer aggregation network is adopted in the modified path aggregation network to enhance feature extraction across various scales. Finally, the proposed model incorporates the Swish function and an extra YOLO head for detection. The experimental results evaluated on the VEDAI dataset demonstrated that the proposed model achieved a higher mean average precision value and generated the smallest model size compared to the other lightweight models. Moreover, the proposed model achieved real-time performance on the NVIDIA Jetson Nano. These findings demonstrate that the proposed model offers the best trade-offs in terms of detection accuracy, model size, and detection time, making it highly suitable for deployment on embedded devices with limited capacity.
Syazwan Ahmad Sabri, Siti Rafidah Abdul Rahim, Azralmukmin Azmi, Syahrul Ashikin Azmi, Muhamad Hatta Hussain, Ismail Musirin,
Volume 21, Issue 2 (6-2025)
Abstract
The Marine Predator Algorithm (MPA) and Osprey Optimization Algorithm (OOA) are nature-inspired metaheuristic techniques used for optimizing the location and sizing of distributed generation (DG) in power distribution systems. MPA simulates marine predators' foraging strategies through Lévy and Brownian movements, while OOA models the hunting and survival tactics of ospreys, known for their remarkable fishing skills. Effective placement and sizing of DG units are crucial for minimizing network losses and ensuring cost efficiency. Improper configurations can lead to overcompensation or undercompensation in the network, increasing operational costs. Different DG technologies, such as photovoltaic (PV), wind, microturbines, and generators, vary significantly in cost and performance, highlighting the importance of selecting the right models and designs. This study compares MPA and OOA in optimizing the placement of multiple DGs with two types of power injection which are active and reactive power. Simulations on the IEEE 69-bus reliability test system, conducted using MATLAB, demonstrated MPA’s superiority, achieving a 69% reduction in active power losses compared to OOA’s 61%, highlighting its potential for more efficient DG placement in power distribution systems. The proposed approach incorporates a DG model encompassing multiple technologies to ensure economic feasibility and improve overall system performance.
Ying Foo Leong, Nizaruddin M. Nasir, Suliana Ab-Ghani, Norazila Jaalam, Nur Huda Ramlan,
Volume 21, Issue 2 (6-2025)
Abstract
This paper focuses on the application of a cascaded multilevel inverter, specifically the 5-level multilevel inverter, utilizing a proposed controller known as the FLC-PSO-PI controller. The primary challenge addressed in this research is the precise regulation of output voltage in the multilevel inverter during load variations while meeting voltage harmonic and transition requirements as per industry standards, which are the 10 % voltage limit recommended by IEC and 8 % of total harmonic distortion (THD) by IEEE. An innovative solution is proposed by integrating PSO and FLC to dynamically adapt the controller in real-time, ensuring stable and accurate output voltage regulation. The proposed controller is designed and simulated using MATLAB/Simulink, and its performance is compared with PSO-PI and no controller under various load conditions. The results demonstrate that the FLC-PSO-PI controller significantly enhances output voltage regulation were achieving the desired peak voltage and low THD across different load scenarios, including half load to full load (0.8 %) and no load to full load (0.89 %). Furthermore, the FLC-PSO-PI controller exhibits superior transient response characteristics, such as reduced overshooting (2.89 %), faster rise time at 36.946 µs, and satisfactory settling time at 151.014 µs. This research contributes to the advancement of multilevel inverter technology and its potential applications in renewable energy systems, motor drives, and grid-connected devices. The proposed FLC-PSO-PI controller offers a promising solution for precise voltage regulation in multilevel inverters, enhancing their performance and enabling widespread adoption in various industrial sectors.
Murni Nabila Mohd Zawawi, Zainuddin Mat Isa, Baharuddin Ismail, Mohd Hafiz Arshad, Ernie Che Mid, Md Hairul Nizam Talib, Muhammad Fitra Zambak,
Volume 21, Issue 2 (6-2025)
Abstract
This study introduces a pioneering method to enhance the efficiency and effectiveness of three-phase five-level reduced switch cascaded H-bridge multilevel inverters (CHB MLI) by employing the Henry Gas Solubility Optimization (HGSO) algorithm. Targeting the selective harmonic elimination (SHE) technique, the research emphasizes the optimization of switching angles to significantly reduce total harmonic distortion (THD) and align the fundamental output voltage closely with the reference voltage. Central to this exploration are three distinct objective functions (OFs), meticulously designed to assess the HGSO algorithm’s performance across various modulation indices. Simulation results, facilitated by PSIM software, illustrate the impactful role these objective functions play in the optimization process. OF1 demonstrated a superior ability in generating low OF values and maintaining a consistent match between reference and fundamental voltages across the modulation index spectrum. Regarding the reduction of THD, it is crucial to emphasize that all OFs can identify the most effective switching angle to minimize THD and eliminate the fifth harmonic to a level below 0.1%. The findings highlight the potential of HGSO in solving complex optimization challenges within power electronics, offering a novel pathway for advancing modulation strategies in CHB MLIs and contributing to the development of more efficient, reliable, and compact power conversion systems.
Huang Yan, Hadi Nabipour Afrouzi, Chin-Leong Wooi , Hieng Tiong Su, Ismat Hijazin,
Volume 21, Issue 2 (6-2025)
Abstract
In order to solve the difficulty of digital signal calibration of electric power equipment, such as low precision, inability to test the full range, and complicated configuration, and further promote the development of power system, a proposed time measurement calibration device is designed, and its performance is verified in this paper. This paper points out the main drawbacks of the existing calibration system, carries on the design innovation of the key technologies based on FPGA (Field Programmable Gate Array), puts forward the optimization method of the software and hardware, and verifies the accuracy of the input and output signal by experiments. The accuracy of input and output SV, GOOSE, and contact signal of the proposed calibration device in this paper can be better than 10μs, which is a meaningful improvement in accuracy and efficiency for time measurement calibration.
Kumuthawathe Ananda-Rao, Steven Taniselass, Afifah Shuhada Rosmi, Aimi Salihah Abdul Nasir, Nor Hanisah Baharudin, Indra Nisja,
Volume 21, Issue 2 (6-2025)
Abstract
This study presents a Fuzzy Logic Controller (FLC)-based Maximum Power Point Tracking (MPPT) system for solar Photovoltaic (PV) setups, integrating PV panels, a boost converter, and battery storage. While FLC is known for its robustness in PV systems, challenges in battery charging and discharging efficiency can affect performance. The research addresses these challenges by optimizing battery charging, preventing overcharging, and enhancing overall system efficiency. The FLC MPPT system is designed to regulate the battery's State of Charge (SOC) while evaluating system performance under varying solar irradiance and temperature conditions. The system is modeled and simulated using MATLAB/Simulink, incorporating the PV system, MPPT algorithm, and models for the PV module and boost converter. System efficiency is assessed under different scenarios, with results showing 97.92% efficiency under Standard Test Conditions (STC) at 1000 W/m² and 25°C. Additionally, mean efficiencies of 97.13% and 96.13% are observed under varying irradiance and temperature, demonstrating the effectiveness of the FLC MPPT in regulating output. The system also extends battery life by optimizing power transfer between the PV module, boost converter, and battery, ensuring regulated SOC.
Mahdi Khourishandiz, Abdollah Amirkhani,
Volume 21, Issue 3 (8-2025)
Abstract
Protecting privacy in street view imagery is a critical challenge in urban analytics, requiring comprehensive and scalable solutions beyond localized obfuscation techniques such as face or license plate blurring. To address this, we propose a novel framework that automatically detects and removes sensitive objects, such as pedestrians and vehicles, ensuring robust privacy preservation while maintaining the visual integrity of the images. Our approach integrates semantic segmentation with 2D priors and multimodal data from cameras and LiDAR to achieve precise object detection in complex urban scenes. Detected regions are seamlessly filled using a large-mask inpainting technique based on fast Fourier convolutions (FFC), enabling efficient generalization to high-resolution imagery. Evaluated on the SemanticKITTI dataset, our method achieves a mean Intersection over Union (mIoU) of 64.9%, surpassing state-of-the-art benchmarks. Despite its reliance on accurate sensor calibration and multimodal data availability, the proposed framework offers a scalable solution for privacy-sensitive applications such as urban mapping, and virtual tourism, delivering high-quality anonymized imagery with minimal artifacts.
Gholamreza Khademevatan, Ali Jalali,
Volume 21, Issue 3 (8-2025)
Abstract
A novel simplified EKV model base analog/RF CMOS design pre-SPICE tool is presented in this paper. Addition to facilitating the sizing process, this CAD tool can also optimize circuit characteristics. By having a web address, users can access it without installing any software. Using a graphical and a numerical view, the designer can select degrees of freedom and observe the MOS circuit performance. Through the use of charts versus IC, the graphical view can show tradeoffs in circuit performance in real-time. Charts can be displayed simultaneously in both linear and logarithmic scales. IC CRIT , is also available and can be displayed on the charts. This tool is not limited to one process and it is possible to select different processes. It is efficient for pre-SPICE designs, enhancing intuitive understanding and the designer's experience for future projects while eliminating the need for trial-and-error simulations. Furthermore, the predicted results align well with simulation outcomes, demonstrating the effectiveness of the design and optimization method presented. Two methodologies for selecting optimum ICs are presented by this tool. These are illustrated by the study of linearity indices, AIP3 and IIP3, in one-stage and two-stage differential amplifiers and the design of a single-ended OTA.
Zahra Memarian, Mahdi Majidi,
Volume 21, Issue 3 (8-2025)
Abstract
This paper presents a two-dimensional (2D) direction of arrival (DOA) estimation method based on the popular correlative interferometer (CI) approach, incorporating practical considerations. Leveraging the flexibility of software-defined radio (SDR) platforms, the proposed array antenna model is designed according to the specifications of a dual-channel synchronous USRP B210 receiver and an appropriate RF switch. To enhance the speed and accuracy of 2D DOA estimation for narrowband, wideband (WB), and frequency hopping (FH) signals, this study introduces a method that integrates power spectrum density (PSD) and spectrogram analysis of the receiver’s instantaneous bandwidth with an optimized filter bank, to precisely detect active frequencies and their intervals. Additionally, a fast, modified K-means clustering algorithm is developed to refine DOA estimation for FH and WB signals across multiple active subchannels. Simulation results demonstrate improved DOA estimation accuracy in multipath conditions, particularly at longer distances, with further enhancements achieved through the proposed clustering method.
Nguyen Nhat Tung,
Volume 21, Issue 3 (8-2025)
Abstract
This paper presents an effective approach for determining optimal integration of renewable energy distributed generator (RE-DGs) of solar farms (SFs) and wind farms (WFs) in IEEE 69-node power distribution network (PDN) with target of minimizing (1) the single objective function of total active power loss and (2) multi-objective function including a) total active power loss, b) total reactive power loss, c) the voltage deviation and d) imported energy from the main power gird. Intelligent and adaptive meta-heuristic optimization algorithm called bonobo optimizer (BO) is introduced to address optimization problem considering the changing four seasons of winter, spring, summer and autumn from both generation and consumption. The obtained results from BO show its outstanding performance in determining the suitable installation of SFs and WFs compared with many published methods and implemented methods for two cases of single and multi-objective functions.
Seyyedeh Ensiyeh Hashemi, Hamid Behnam,
Volume 21, Issue 3 (8-2025)
Abstract
Increasing the frame rate of ultrasound imaging while keeping image quality is important for following fast movements, especially the heart. There are different modalities for B-mode image recording, including line-by-line scanning with linear, phased, convex array, synthetic aperture imaging (STA), plane waves (PWI), then the combination of plane waves (CPWI), and so on. Researchers have tried to increase the frame rate in each case using different methods. Three approaches for this aim are data acquisition, post-processing, and beamforming. This article reviews these approaches and their solutions for compensating image quality reduction. Ultrafast ultrasound imaging, which provides exceptional temporal resolution (high frame rate), is promising in diagnosing heart diseases due to its ability to capture rapid heart movements. It can record images faster than conventional imaging, usually exceeding 1000 frames per second. This can be achieved through plane wave imaging (PWI). However, high frame rate data acquisition can lead to a decrease in image quality. Transmitting at different angles and then combining plane wave imaging is a popular method to enhance PWI quality but reduces the frame rate by the number of angles. As a result, researchers have aimed to increase the temporal resolution while compensating for the loss of quality.
Masoud Hashemi, Mohsen Kalantar,
Volume 21, Issue 4 (11-2025)
Abstract
The basis of the extensive measurement systems is based on the placement of phasor measurement units (PMUs) in the power grids. With the ever increasing expansion of electric energy consumption and the emergence of the phenomenon of restructuring in power grids and the existence of problems such as extensive blackouts of the power grid has increased the desire of power grid operators to use a wide area monitoring system (WAMS). This paper discusses the problem of optimal placement of phasor measurement units (PMUs) in power grids, which is a critical issue for the reliable and safe operation of power systems. We proposed a multi-objective binary optimization algorithm called the Multi-Objective Binary Harris Hawks Optimization algorithm based on Region selection (MOBHHO/R) to solve this problem. One of the most important innovations of the proposed algorithm is to draw inspiration from feature called a repository or archive to store optimal responses at each stage of the simulation. The algorithm aims to minimize the number of PMUs required while maximizing the observability of the power grids. The proposed algorithm is implemented on the standard IEEE 14 and 30 bus power systems, and the results show its superiority compared to other algorithms.
Majid Golkhatab, Aref Shahmansoorian, Mohsen Davoudi,
Volume 21, Issue 4 (11-2025)
Abstract
This paper presents a novel hybrid navigation approach for autonomous mobile robots in obstacle-rich environments. The method integrates artificial potential fields for obstacle avoidance with fuzzy logic for path planning, which is optimized by a genetic algorithm to enhance adaptability and robustness to sensor uncertainties. Experimental results demonstrate significant improvements over traditional artificial potential field methods and are validated through real-time implementation on a ROS-based mobile robot.
Suhail Mahmoud Abdullah, Thamir Hassan Atyia,
Volume 21, Issue 4 (11-2025)
Abstract
Optimal control of DC motors remains a critical research area in modern control systems, given their wide industrial applications and the need for accurate performance under variable conditions. This paper explores the application of genetic algorithms (GAs) to optimize the control parameters of DC motors, particularly PID controllers, with the goal of improving the dynamic response and robustness of DC motor systems. Compared to traditional constraint-based tuning methods, GAs, inspired by natural selection and evolution, offer comprehensive search capabilities that significantly improve parameter optimization, providing better speed regulation, reduced overshoot, and minimal steady-state error. This review highlights the key challenges faced when using GAs. Comparative results from various studies demonstrate that GA-based controllers consistently outperform traditional tuning methods in terms of stability, efficiency, and adaptability. Key findings related to energy consumption and stability are highlighted. It is essential to analyze the system performance in terms of rise time (tr), settling time (ts), overshoot ratio (Mp%), and steady-state error (Ess). A proportional-integral-differential (PID) controller provides a stable response by tuning its parameters according to a specific methodology using a genetic algorithm. This paper concludes by emphasizing the potential of genetic generators as a powerful and flexible optimization tool for intelligent control of DC motors.
Hamid Reza Sezavar, Saeed Hasanzadeh,
Volume 21, Issue 4 (11-2025)
Abstract
Marx generators that produce output pulses in the range of a few kilovolts (kV) with energies of a few millijoules (mJ) and rise times of a few nanoseconds (ns) have a variety of applications, including enhancing hydrogen production through electrolysis. In these generators, bipolar junction transistors (BJTs) operating in avalanche breakdown mode are employed as switches. This study explores the use of transistors specifically designed for avalanche breakdown to improve hydrogen generation efficiency from renewable energy sources. For this purpose, the FMMT415 transistor was implemented in the generator. The designed circuit was simulated with the transistors in avalanche breakdown mode, and the effects of various parameters on the output voltage were examined, particularly in the context of optimizing electrolysis performance. Based on the simulation results, the circuit was constructed and tested, and the differences in transistor parameters were evaluated. The simulation outcomes were then compared with the actual results. From these investigations, criteria were developed to determine the parameters that ensure suitable output voltage for Marx generator applications in hydrogen production. The optimal number of stages for the Marx generator was estimated based on the findings, highlighting its potential role in advancing sustainable hydrogen energy systems.
Rupika Gandotra, Kirti Pal,
Volume 22, Issue 1 (3-2026)
Abstract
The rising demand for electricity has led to the installation of renewable-based distributed generators in a power system network to meet the increasing load. The eco-friendly nature of these DGs is another compelling reason to incorporate them in a power system network but their installation process requires careful consideration such as determining the optimal quantity and location because these factors have a significant impact on various constraints and parameters of the power system network. The main objective of this paper is to determine the optimal siting and sizing of Type-1 and Type-2 DGs in a power system network such that network has minimum real and reactive power losses in the transmission lines, also fuel cost of convectional generators is reduced and voltage profile is improved. For this purpose, hybrid GA-PSO approach is developed and implemented on case 33 bus system and results were compared under different loading conditions such as 100%, 150%, 200% to show which type of DG is most effective. Further, the evaluated results have been compared with other algorithms including OCDE, WOA, SFSA, TGA and EJSA in order to ensure the validity of the suggested approach. The numerical results validate the performance of this proposed technique for DG unit placement.
Mohammad Ali Razavi, Farid Tootoonchian, Zahra Nasiri Gheidari,
Volume 22, Issue 1 (3-2026)
Abstract
Synchros are electromagnetic sensors utilized to determine the angular position of a rotating shaft. This paper examines the impact of leakage flux from the Rotary Transformer (RT) on the induced voltages and the position detection accuracy of the Wound-Rotor (WR) synchro. Various methods are proposed to mitigate the negative effects of leakage flux from the RT. The leakage flux paths, which couple with the signal winding, are identified. Based on this analysis, the optimal distance between the sensor and the RT is calculated to minimize the adverse effects of leakage flux on the synchro's accuracy. Additionally, the RT structure is modified to reduce the leakage flux. Another effective approach involves the use of Electromagnetic Interference (EMI) shielding. In this context, a shield frame is designed for the RT, and the impact of different shield materials on reducing leakage flux is investigated. The results show that a copper-based shield significantly reduces the adverse effects of leakage flux and improves the sensor’s accuracy. To evaluate the effectiveness of the proposed methods, they are assessed through 3-D Time-Stepping Finite Element Analysis (3-D TSFEA) and experimental measurements on a prototype sensor. The experimental results show close agreement with the 3-D TSFEA, confirming the accuracy of the findings.
Ali Esmaeilvandi, Mohammad Hamed Samimi, Amir Abbas Shayegani Akmal,
Volume 22, Issue 1 (3-2026)
Abstract
This paper introduces an improved multi-conductor transmission line (MTL) model for transformers' high-frequency transient and frequency response analysis, overcoming limitations in traditional models that fail to capture complex electromagnetic interactions during high-frequency events, such as lightning strikes and switching operations. The model accurately reflects real-world transformer behaviors under transient conditions by integrating particle swarm optimization (PSO) for efficient parameter estimation and incorporating frequency-dependent losses. The combined use of PSCAD and Python minimizes computational overhead, enabling high-fidelity simulations closely aligned with experimental transformer data. Validation against real transformer measurements demonstrates the model’s reliability in capturing high-frequency responses, essential for transformer diagnostics. This novel approach offers a practical tool for studying transformer frequency response analysis, which is an important tool in transformer diagnosis.
Ali Amini, Farshid Mahmouditabar, Nick Baker, Abolfazl Vahedi,
Volume 22, Issue 1 (3-2026)
Abstract
In recent years, due to the increase in electricity generation, the need for optimized Wound Rotor Synchronous Generators (WRSGs) has been felt more than ever. One of the important characteristics of a generator in a power system is its voltage harmonics. In addition to this, the amount of generated power and efficiency are also important. The goal of this research is multi-objective design using dampers, with improved number and shape. WRSGs have been selected as a case study. With the help of surrogate modeling and the PSO algorithm, which are more efficient and accurate than classical methods, the final design has been presented. In the end, the comparison of the initial and final designs shows the realization of all goals. Also, economic issues in terms of the selection of damper material have been investigated.
