The Internet of Things (IoT) is a transformative technology facilitating seamless communication between diverse devices and systems, including resource-constrained devices. Speed efficiency and energy efficiency in communication protocols for IoT devices are crucial. The constrained application protocol (CoAP) is a promising, lightweight, and efficient protocol for IoT, offering robust messaging capabilities while conserving resources. An emerging research focus and challenge is designing hardware accelerators for CoAP that are fast, energy-efficient, and reliable. This article addresses that research challenge by proposing a CoAP hardware accelerator for optimizing message processing in resource-constrained IoT environments. The proposed accelerator’s architecture uses virtual channels (VCs) to manage incoming message traffic efficiently, enabling concurrent processing and enhancing throughput capacity.

Epilepsy triggers seizures, which develop before clinical onset in patients, and a timely and accurate prediction can save lives. A research challenge is to design accurate, fast, and energy-efficient hardware predictors. This work advances hardware-based seizure prediction research by proposing a new machine-learning-based predictor. It proposes a novel reconfigurable electroencephalogram (EEG) signal segmentation for increased learning. The proposed reconfigurable segmentation adaptively adjusts the overlap extent between consecutive segments and prepares new segments. Such prepared segments are fed into a Convolutional Auto-Encoder (CAE) using a proposed convolution module. The proposed convolution module uses optimized hyperparameters, including the number of layers, filters, filter size, pooling method, stride value, and padding for high learning and feature extraction. The learned CAE …

Due to technological advancement, the advent of smart cities has facilitated the deployment of advanced urban management systems. This integration has been made possible through the Internet of Vehicles (IoV), a foundational technology. By connecting smart cities with vehicles, the IoV enhances the safety and efficiency of transportation. This interconnected system facilitates wireless communication among vehicles, enabling the exchange of crucial traffic information. However, this significant technological advancement also raises concerns regarding privacy for individual users. This paper presents an innovative privacy-preserving authentication scheme focusing on IoV using physical unclonable functions (PUFs). This scheme employs the k-nearest neighbor (KNN) encryption technique, which possesses a multi-multi searching property. The main objective of this scheme is to authenticate autonomous vehicles (AVs) within the IoV framework. An innovative PUF design is applied to generate random keys for our authentication scheme to enhance security. This two-layer security approach protects against various cyber-attacks, including fraudulent identities, man-in-the-middle attacks, and unauthorized access to individual user information. Due to the substantial amount of information that needs to be processed for authentication purposes, our scheme is implemented using hardware acceleration on an Nexys A7-100T FPGA board. Our analysis of privacy and security illustrates the effective accomplishment of specified design goals. Furthermore, the performance analysis reveals that our approach imposes a minimal communication and …

Alzheimer’s Disease (AD), the prevailing form of dementia, is a neurological condition that significantly impacts individuals globally, leading to devastating effects. The early detection of AD is of paramount importance in mitigating its impact. Numerous methodologies have been suggested for diagnosing AD through medical imaging techniques such as positron emission tomography (PET) and magnetic resonance imaging (MRI). Nevertheless, it is anticipated that utilizing blood biomarkers would enhance the identification of individuals with AD and cognitive impairments. This paper introduces an innovative distributed deep-learning methodology for the early identification of AD through the analysis of blood samples. This study aims to investigate the application of federated learning (FL) in the analysis of blood samples to predict the likelihood of getting AD. Our study employed a dataset of many blood …

Electrical stimulation of neuromuscular tissues has been proven to treat many spinal cord injury-related clinical disorders, such as motor function restoration, epilepsy treatment, and other biomedical applications. Implantable electrical stimulators have emerged as promising solutions for long-term therapeutic and scientific biomedical purposes. However, designing such stimulators presents many challenges. This paper introduces an integrated circuit for an implantable electrical stimulator with high stimulation efficiency and a small on-chip area of 0.0833 mm 2. The device is capable of delivering a programmable stimulation current of up to 800 μ A to a load impedance of 2.5 k Ω while maintaining linearity. A power efficiency of 75.15% was achieved. The stimulator can deliver higher currents when connected to lower load impedances.

Glass fiber-reinforced plastics are an important composite material in the marine, automotive, and military industries due to their excellent mechanical properties, such as high strength, corrosion resistance and lightweight. This study aims to determine the effect of the number of glass fiber layers on the hardness of glass fiber/polyester composite materials. Random chopped strand mat glass fibers with a mass per unit area of ​​450 g/m² were used to prepare samples using the hand layup technique. The number of layers varied between 3 to 6 layers. The thickness of all samples is 3 mm. The Vickers microhardness device is used to measure the hardness, with a load of 50 g applied for a dwell time of 15 s. The results indicated that when increasing the number of glass fiber layers decreases the hardness values. The sample of three-layer listed the highest hardness value of 14.34 HV, while the values ​​for the four-layer sample decreased to 11.42 HV, the five-layer sample to 9.72 HV, and the six-layer sample had the lowest value of 7.7 HV. This decrease in hardness is attributed to the increased number of interfaces between layers, which may lead to the appearance of weak points or air voids that affect the mechanical properties of the composite material.

Glass fiber/polyester composites are increasingly used in naval, aerospace, and automotive industries due to their excellent strength-to-weight ratio and corrosion resistance. However, drilling-induced delamination remains a major concern that compromises hole quality and structural performance. In this study, the drilling behavior of randomly oriented chopped strand mat GFRP/polyester laminates (3 mm thickness, 5 layers, 450 g/m² areal density) was experimentally investigated under varying spindle speeds (1000–2000 RPM), feed rates (100–300 mm/min), and drill diameters (5, 8, and 10 mm). Hole quality was evaluated using AutoCAD-based measurement of the delamination factor. The results show that delamination factor increases with feed rate, while higher spindle speeds reduce it, in agreement with previous studies that attribute this behavior to reduced thrust forces. Among the tested conditions, the lowest delamination factor (≈1.09) was obtained at 1500 RPM and 100 mm/min feed rate, whereas the highest (≈1.54) occurred at 1000 RPM and 300 mm/min. The contribution of this work lies in focusing on the underexplored chopped strand mat GFRP/polyester composites and employing AutoCAD-based quantitative assessment, providing new insights and a practical baseline for improving drilling performance in these materials.

This paper introduces a compact wideband Reconfigurable Intelligent Surface (RIS) leveraging Schiffman phase shifters to overcome the traditional narrowband limitations of RIS technology. The proposed design achieves ±15° phase balance across a broad frequency range of 7.5–13 GHz, addressing a key challenge in RIS design. The proposed RIS features a compact unit cell, with dimensions of (0.25λ×0.25λ) at 10.25 GHz, integrating a single PIN diode and a tailored internal geometry to enable efficient phase control and scalable implementation. Experimental validation is carried out in two phases: initially, the unit cell is characterized using a waveguide setup; subsequently, a 30 cm×30 cm RIS panel is fabricated and tested under horn antenna excitation. The measured data exhibit strong agreement with simulations, demonstrating the accuracy and robustness of the proposed design. The full RIS surface is further evaluated for its reconfigurability and ability to generate Orbital Angular Momentum (OAM) beam scanning. These findings highlight the design’s potential for enabling key 6G communication features, offering a compact and wideband RIS solution through the integration of Schiffman phase shifters and contributing to advancements in next-generation wireless systems.

This paper introduces an innovative design and analysis of a magneto-electric dipole antenna exhibiting high-gain, ultra-wideband operation, and stable radiation characteristics in the 60-GHz mm-wave band. Furthermore, the trapped printed gap waveguide (TPGW) technology is presented as a low-cost, minimal-loss, and low-dispersion guiding structure to feed the proposed antenna. The antenna covers a relative matching bandwidth of over 33.33% from 50 to 70 GHz with a maximum gain up to 8 dBi. In addition, the antenna is integrated with a perforated dielectric substrate layer lens on the antenna’s broadside location, enhancing the gain by an average of 3 dB along its entire operational bandwidth. Moreover, an efficient approach for designing a large ME dipole antenna array and its corporate feeding network is presented. Both ME-dipole sub-arrays and the out-of-phase power divider with WR-15 standard interface are designed and studied separately, where a systematic design procedure is presented to obtain initial design parameters. A 2 × 2 planar antenna array is designed and implemented, featuring proper integration between the radiating elements and a differentially fed wide-bandwidth TPGW power divider. Then, the operation of the individual components has been assessed using simulation and measurements. Furthermore, an in-depth mathematical analysis is presented to investigate the potential resonance conditions arising from disparities in complementary components. Consequently, a proposed solution is provided to break the resonance loop and shield the two opposing sub-arrays. The 2 × 2 array of ME-dipoles has overall dimensions of 1.6 1.4 and demonstrates an impedance bandwidth (– 10 dB) exceeding 33.33 at 60 GHz, with a peak gain of over 18 dBi.

Frequency-Selective Surfaces (FSSs) are structures designed to selectively transmit or reflect electromagnetic waves, making them essential for applications requiring precise control over frequency bands and wave propagation characteristics. However, traditional FSS designs face challenges such as fixed geometries, limited scalability, and poor bandwidth efficiency, often requiring compromises between size reduction and performance. To address these limitations, this work introduces the use of Stepped Impedance Resonators (SIRs) to synthesize miniaturized FSS structures with four-legged elements (FLEs). By combining transmission line theory, SIR equations, and parallel coplanar stripline models, an innovative synthesis method is proposed, enabling precise control over spurious frequencies and resulting in a 54% reduction in unit-cell size without sacrificing performance. This approach significantly enhances the feasibility of compact FSS applications. To further improve performance, an arrow-bending technique was introduced to reduce the coupling between adjacent cells, yielding a 30% improvement in isolation. Three distinct surface designs have been fabricated and tested under both normal incidence and oblique angles for TE and TM modes. These designs include the SIR-based FSS cell, an enhanced design featuring arrow bending, and a reverse arrow formation intended to reduce edge effects between adjacent cells. Additionally, measurements demonstrate excellent performance stability, with tolerance maintained for incident angles up to 60◦ . Experimental validation confirms effective blocking at 10 GHz and highlights the robustness of the design across varying incident angles. Prototypes fabricated from the miniaturized FSS elements show excellent agreement with simulations, underscoring the potential of this method for advanced applications in communications, radar, and electromagnetic shielding.