Alzheimer's disease (AD) is a brain degenerative disease, so the Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET) of cerebral images are effective data in detecting the onset of the disease. In this work, a framework consisting of a cross attention multimodal fusion deep neural network and a patches weight optimization strategy is proposed. First, multiple points are randomly selected from the region of interest (ROI), and multiple 3-axial-plane patches are extracted centered on these points. Then, the patches from MRI and PET are fused using a fusion neural network to output diagnostic information for each patch. Finally, a weight is set for each patch; a particle swarm optimization algorithm is used to find the optimal weights for multiple patches; the diagnostic information from multiple patches is merged using these weights; and the final diagnostic results are output. The experiments on ADNI dataset show that this method has an accuracy of 94.03% in diagnosing AD and outperforms other methods of fusing MRI and PET data, which demonstrates the promising performance of this method.

Double-Sided Flux Switching Permanent Magnet Linear (DLFSPM) motors are characterized by high efficiency and high power density, which are more and more widely used in various fields, so the design of high-performance linear flux-switching PM motors is of great significance to improving the efficiency of industrial applications. This study aims to achieve the improvement of electromagnetic thrust of double-sided flux switching permanent magnet linear motor by optimizing the motor core structure. First, a theoretical approach is used to construct the motor model and derive the electromagnetic thrust equation. Second, the finite element and Bessel curve fitting methods are used to optimize the core structure to enhance the electromagnetic thrust. Subsequently, the conductive bridge structure is increased to reduce the detent force and improve the performance. Then, the modular structure of primary iron core unit is proposed based on the above two optimizations. Finally, finite element simulation of the proposed optimized structure is carried out to compare the electromagnetic performance of the final comprehensively optimized DLFSPM motor with that of the motor of the initial structure. It is found that the average electromagnetic thrust is increased by 57.85%, and the amplitude of the detent force is reduced by 48.34%, which verifies the effectiveness of the optimization method.

This article introduces a Circularly-Polarized (CP) inverted cup-shaped Hybrid Cylindrical-Dielectric-Resonator-Antenna (HCDRA) combined with an asymmetric Jerusalem cross unit-cell based metasurface (MTS). The antenna, designed for use in the 5G n-79 NR band (4400-5000 MHz) and IEEE 802.11n-WLAN (5 GHz) applications, features a unique disturbed coax-feed mechanism at the edge of cylindrical DR and an asymmetric MTS that boosts the circular polarization within the DR antenna. The antenna's E-field and parametric analysis provide evidence of CP radiation. The proposed HCDRA achieves impressive S₁₁ and Axial-Ratio (AR) bandwidths of 2.1 GHz and 740 MHz, with a maximum gain of 6.825 dBic. The overall gain obtained is consistently more than 5.5 dBic across the entire bandwidth of the HCDRA. The fabricated HCDRA is tested in an anechoic chamber, and the obtained practical results closely matched the simulation outcomes, confirming the performance of the proposed design.

The paper describes a two-layer low-profile antenna design suitable for sub-6 GHz communications that operates at 5.8 GHz. The proposed antenna is integrated with a periodic plus-shaped EBG structure to obtain gain and bandwidth enhancement. The realized gains of the prototype with and without periodic structure are 3.48 dBi and 2.4 dBi, respectively. Additionally, it is observed that the measured bandwidth of the antenna structure at 5.75 GHz with periodic structure is 230 MHz, while without periodic structure it is 150 MHz, which accounts for 35% bandwidth enhancement. The simulated and measured results validate that the proposed compact antenna prototype is a suitable candidate for sub-6 GHz application in the 5G spectrum.

This article introduces a quad-port Multiple Input Multiple Output (MIMO) staircase U-shaped wideband antenna for a 5G New Radio (NR) wireless. The miniaturization of the configuration is achieved with a staircase U-shaped radiating element, and an I-shaped stub etched with rectangular strips between radiating elements provides enhanced isolation. The measured bandwidth of 4.5 GHz is obtained with an isolation, radiation efficiency, and gain above 17 dB, 80%, and 6.5 dB respectively. Certain parameters, such as envelope correlation coefficient (ECC), diversity gain (DG), mean effective gain (MEG), channel capacity loss (CCL), and total active reflection coefficient (TARC), are also evaluated to ensure that the designed MIMO system adheres to its requirements. Hence, the suggested antenna suits the 5G New Radio applications.

The paper presents array-pattern synthesis for wide-band nulling at specified directions. The projection matrix method is invoked to obtain an orthogonal operator matrix (OOM). The OOM transforms a quiescent excitation vector to an optimally modified excitation vector that warrants ideal nulls at the desired directions at multiple frequencies. However, the modified excitation does not provide the optimal solution for a shaped beam, particularly near the edge-of-coverage region. We obtain an improved shaped beam solution by determining a complete set of orthonormal basis vectors that represent the column space of the OOM. Optimum amplitudes of the basis vectors yield an improved shaped beam. The method is amended for nulls in phased array-fed reflector (PAFR) antenna patterns. The method does not require explicit determination of eigenvalues and eigenvectors, thereby enhancing the computation efficiency facilitating easy implementation in a digital processor. As a consequence, real time nulling in phased arrays and PAFRs are feasible with minimal computation burden, appealing to communication satellites.

This work proposes a compact multiband Symmetrically Stepped Phase Cancellation Reflective Surface (PCRS) that can be used to lower radar cross section (RCS), achieve high Absorption Conversion Ratio (ACR) and high Polarization Conversion Ratio (PCR). Two FR4 layers make up the Symmetrically Stepped PCRS unit cell. With three asymmetrically positioned vias along its diagonal, the Symmetrically Stepped patch is present in the first FR4 layer, which has a thickness (t1) of 1.6 mm and high PCR and ACR. On top of layer 1, there is another layer of FR4 stacked with a thickness (t2) of 3.2 mm to give multiple bands with improved bandwidth efficiency. The PCRS unit cell's entire dimensions, which are only 5 mm x 5 mm x 4.8 mm, are determined by its lowest operational wavelength. Multiple frequencies, 5.6 GHz, 9.8 GHz, 11.3 GHz, and 16.7 GHz, yield RCS reductions of 24 dB, 33 dB, 42 dB, and 24 dB, respectively. 99.9% maximum PCR and 99.9% maximum ACR are obtained with up to 60 degrees of angular stability. Furthermore, in order to minimize RCS and prevent unnecessary reflections from the PCRS, the proposed reflective PCRS unit cells are positioned orthogonally to offer reflection phase cancellation. The most important objective of the proposed research is to lower the RCS while maintaining high PCR and ACR in various frequency bands that are necessary for detection and stealth technologies.

Aiming at the operation stability of transformer with harmonic invasion in offshore wind farm, the evolution and propagation of electromagnetic-solid-acoustic information are studied. Combined with the measured data of invasive harmonic currents, it is found that the proportions of the 5th and 7th harmonics are larger than those of other harmonics. A multi-physical field propagation and information extraction method for transformer is proposed based on the principle of electromagnetic-solid-acoustic coupling. Then, the magnetic density, force, vibration, and noise characteristics of components with harmonic invasion are analyzed. The results show that the increase of harmonics intensifies the vibration and noise of transformer in the same load. In the same harmonic proportion, the waveform distortion of the multi-physical characteristic parameters caused by the 7th harmonic is more significant than the 5th. Moreover, the vibration and noise intensify with rising load factor in the same harmonic invasion mode. Meanwhile, the dynamic experimental platforms are built to measure multi-physics field information in different modes. By comparing the experimental data and simulation result, the accuracy of proposed method can be verified. Furthermore, the 5th harmonic is selected as the typical characterization parameter to study the mapping relationship between harmonics and vibration characteristics. The criteria for disturbed destabilization are formulated, providing new ideas for the life cycle operation and maintenance of offshore wind transformer.

This work, for the first time to our knowledge, describes in detail the incorporation of the numerical and semi-analytical intelligent reflector scattering models into the modelling framework of the state-of-art dual-polarization three-dimensional geometrical channel models, where propagation channel impact and antennas impact are separated. The proposed formalism allows indoor coverage impact studies of the meta reflectors in mmWave and THz radio communication systems. The model considers reflector phase-design, near-field effects, polarization transformations, incident beam patterns, multipath and diffraction effects, and is confirmed by full-wave simulations and measurements.

In this work, we propose a technique to enhance the performance of circular patch antennas using an embedded system of cylindrical impedance surfaces. The technique utilizes a derived analytical model of a circular patch antenna containing an arbitrary number of coaxial impedance surfaces along with nonlinear optimization algorithms. This allows for the calculation of the radius and impedance of each surface to achieve the desired matching frequency band for given antenna dimensions. We demonstrate two applications of adding an optimal set of impedance surfaces into a compact circular patch antenna, i.e., the expansion of the matching frequency band keeping constant antenna dimensions and the miniaturization (height reduction) maintaining the constant bandwidth. Two corresponding versions of a cavity-backed circular patch antenna each having three impedance surfaces are synthesized. Practical implementations for both versions are designed and considered in full-wave numerical verification of analytically predicted properties. A comparison with the conventional method using multi-element microstrip matching circuits shows a benefit in radiation efficiency.

In this paper, an optimized flexible Microstrip Patch Antenna (MPA) for wearable applications is introduced, particularly characterized by its design concepts of scalable design and comprehensive performance evaluation. The proposed antenna leverages the mechanical flexibility of a leather substrate, complemented by polyimide layers on the upper and lower surfaces of the copper patch, enhancing both structural integrity and electromagnetic performance. The design is optimized for the operation at 2.4\,GHz, ensuring durability and stability even under dynamic bending conditions. Various critical performance metrics, such as resonance frequency, bandwidth, return loss, Voltage Standing Wave Ratio (VSWR), Specific Absorption Rate (SAR) and gain, are evaluated experimentally and through simulation across bending angles of 0-90°. Results also show that the antenna can reliably operate in an extreme bending scenario while having a resonant frequency near 2.44 GHz with a return loss (S₁₁) less than -20 dB up to 60° bending. At approximately 31 MHz bandwidth stability is preserved, and the VSWR is less than 1.2, thus the impedance matching is effective. Further gain measurements are also made under deformation, which further confirms the stable performance and thus reliability of the wearable application. Additionally, SAR analysis is conducted to ensure the antenna's compliance with electromagnetic exposure safety limits. The maximum SAR value of 0.516 W/kg remains well within FCC (1.6 W/kg) and ICNIRP (2.0 W/kg) standards, confirming safe radiation levels. Polyimide shielding improves durability, reduces interference, and minimizes backward radiation, making the design ideal for Wireless Body Area Networks (WBANs) and biomedical monitoring.

In order to solve the problems of susceptibility to environmental disturbances, complex installation and low reliability caused by the photoelectric code disks in the permanent magnet assisted bearingless synchronous reluctance motor (PMa-BSynRM) system, an improved BP neural network (BPNN) left-inverse system is proposed to establish the speed self-sensing system of the PMa-BSynRM. Firstly, the mathematical model of the PMa-BSynRM is established, and the left reversibility of the PMa-BSynRM speed subsystem is analyzed. Secondly, the traditional BP neural network is optimized from four aspects, including the number of neurons in the hidden layer, initial weight, connection weight and learning rate. Then, the improved BPNN model is used as the inverse model of the left inverse system to fit the speed subsystem of the PMa-BSynRM. Finally, the simulation results show that accurate estimation of the speed and rotor position is achieved by the proposed speed self-detection system, and the accuracy and feasibility of the proposed speed self-detection system are validated by the experimental results.

This paper describes the low sidelobe pattern synthesis of planar arrays having a distorted triangular or rectangular lattice. This distortion concerns variable row displacements applied to a triangular, skew or rectangular element lattice. The applied low sidelobe pattern synthesis is based on the iterative Fourier transform (IFT) method that makes extensive use of forward and inverse FFTs. Recently this author has developed new forward and inverse 2D FFT formulations. Due to these two new FFT formulations, the application of the IFT method is no longer limited to the pattern synthesis of a planar array having a rectangular lattice but can now also be applied to array apertures with a triangular or skew element lattice and even when such lattice has displaced element rows. The new IFT method is employed in this paper for the low sidelobe pattern synthesis of arrays featuring displaced element rows. The presented synthesized pattern results, which refer to the sum pattern, concern three planar arrays each with displaced element rows applied to a square or triangular lattice. The sum pattern of the considered antennas has to meet peak sidelobe level (PSLL) requirements for two nulling ring sectors, one of ≤-50 dB and the other of ≤-68 dB. The sum pattern of the third example includes a rectangular nulling sector specified by a PSLL of <– 80 dB.

In this paper, we present a miniaturized design of a microstrip antenna achieved through the Combination of Minkowski-Sierpinski(M-S) fractal structure and meandering technique, enabling the antenna to be integrated into smaller systems. The antenna achieves right-hand circular polarization (RHCP) through chamfering on a square patch. Further miniaturization is accomplished by loading four symmetrically opposed L-shaped slots along with M-S fractal structure. Specifically, the Minkowski structure undergoes a single iteration, while the Sierpinski fractal is iterated twice on the once-iterated Minkowski fractal to optimize performance. The antenna is manufactured on a textile substrate TLX-8 with dimensions of 50 mm × 50 mm × 0.762 mm, representing a 54.3% reduction in size compared to traditional designs. Moreover, the substrate exhibits robust mechanical properties. Experimental results demonstrate that the antenna achieves excellent radiation characteristics within a bandwidth of 1.563 to 1.581 GHz, an axial ratio bandwidth of 1.569 to 1.578 GHz. These performance metrics meet the requirements for modern Global Positioning System (GPS) antenna applications, highlighting the design's suitability for advanced integration in contemporary electronic systems.

Aiming at the problems of adjusting the weighting factor, significant torque ripple, and insufficient robustness against load disturbances in conventional model predictive torque control (MPTC) for PMSM, an improved model predictive torque control (IMPTC) strategy incorporating a decoupled sliding mode disturbance observer (DSMDO) is proposed. Firstly, the cost function is divided into two components, and both of them are evaluated sequentially to eliminate the need for weighting factors. Secondly, the set of candidate voltage vectors (VVs) is expanded by the VVs modulation technique to reduce the torque ripple, and a low-complexity method is introduced to determine the sector. Subsequently, the action time of the optimal VV is further corrected, which enhances the control of flux while reducing computational complexity. Additionally, a novel sliding mode disturbance observer with decoupling capability is introduced, which offers feedforward compensation to the speed loop and improves system robustness against disturbances. Finally, the correctness and effectiveness of the proposed IMPTC strategy with DSMDO are proved by the experimental results.

Aiming at the problem of low robustness of fuzzy adaptive control when it is applied to permanent magnet synchronous motor system (PMSM), the study introduced the sliding film control method to optimize it, so as to enhance the robustness of PMSM. The results demonstrated that the torque error of the adaptive fuzzy sliding mode control(AFSMC) was 1.86 Nm, which is 62.8% and 38% less than the peak torque pulsation of 5 Nm and 3 Nm for the fuzzy adaptive control, respectively, and indicates a better steady-state capability when the motor is operated at 1500 rpm and 30 Nm load. In addition, in the robustness validation experiments, under the initial stage, the two methods have the same rotational speed response, but after the parameter changes, the AFSMC adjusts quickly, while the traditional fuzzy adaptive control responds slowly. Moreover, under the same load inertia, the AFSMC exhibits smaller overshoot and faster regulation, smaller speed fluctuation and faster recovery during load surge. In complex scenarios, AFSMC reduces recovery time by 60% over traditional control methods, which demonstrates that the fuzzy adaptive sliding film control proposed by the study is successful in enhancing the system's stability and capability when the PMSM is applied.

In this paper, a multi-layer decoupling metamaterial unit (ML-DMU) is proposed to reduce the mutual coupling in a Yagi-antenna array. ML-DMU is a three-layer structure which is composed of two types of decoupling unit named top and bottom unit, middle unit, respectively. On this basis, the |S21| of proposed array is reduced to less than -23 dB from 2.36 GHz to 3.02 GHz while the antenna volume is not changed. The maximum gain of antenna element in the proposed antenna is 6.56 dBi at 3GHz, which is greater than the antenna without ML-DMU, but smaller than a single antenna element. Compared with other composite decoupling structures, the decoupling structure proposed in this paper has a more stable radiation performance and is simple and easy to install, which makes it have a good prospect in the field of 5G communication and the field of near-earth ground penetrating radar.

A deadbeat control method based on an improved parameter identification algorithm is proposed to improve the control accuracy and rapidity of permanent magnet synchronous motorized spindle (PMSMS). Firstly, based on the mathematical model of PMSMS and Euler discretization formula, the current prediction equation is established. Secondly, the deadbeat control logic is described; the deadbeat control model is established; and the influence of parameters on the system stability is analyzed. Thirdly, in order to improve the parameter robustness of deadbeat control, an improved adaptive parameter identification algorithm is proposed, which combines the least mean square algorithm and the recursive least square algorithm. Based on the voltage equation, the inductance and flux linkage parameters are identified, and then a more accurate parameter identification effect is achieved. Finally, the proposed algorithm is verified by experiments on the experimental platform. Experimental results show that the proposed algorithm has better control accuracy, faster response speed and stronger stability than vector control method and traditional deadbeat control method.

Accurately identifying and calibrating reinforcement bars in concrete is a significant challenge due to their invisibility. This paper proposes a deep learning-based method using magnetic resonance eddy penetrating imaging (MREPI) to acquire data on steel bars embedded in concrete. The data is processed into images and input into the Skel-Unet neural network to extract angle and position information of the central axis of the steel bars. Based on this information, the steel bar diameters are determined. A novel image reconstruction method is also introduced to integrate rebar dimension variations for precise calibration. Experimental results show that the Skel-Unet model achieves high accuracy, with training and testing loss values below 0.01, and F1 score reaches 0.7436. The reconstructed images clearly delineate the position, dimensions, and orientation of the rebars, enhancing calibration and nondestructive testing in structural health monitoring.

This paper presents a switchable terahertz metamaterial device based on vanadium dioxide (VO₂). By leveraging its phase transition properties, the device achieves broadband absorption and polarization conversion functionality through the insulator-to-metal transition (IMT) induced by temperature modulation. When VO₂ is metallic, the device functions as a broadband absorber. achieving an absorption rate exceeding 90% within the frequency range of 2.2 to 4.4 THz. Conversely, when VO₂ is in its insulating state, the device enables polarization conversion of incident terahertz waves. Simulation results reveal that in this state, the cross-polarized reflection coefficient (Ryx) exceeds 0.8, while the co-polarized reflection coefficient (Rxx) is significantly suppressed, indicating efficient conversion from co-polarization to cross-polarization within the 1.4 to 2.1 THz range. Notably, the polarization conversion rate approaches unity in this frequency band. Additionally, the study investigates the influence of the structure's geometric parameters, incident angle, and polarization angle on its performance. The results highlight the device's robust tolerance to variations in these parameters, as well as its low manufacturing precision requirements. The proposed multifunctional switchable terahertz metamaterial device holds significant potential for applications in terahertz research, polarization filtering, and terahertz invisibility technologies.