Search Results (417)

This article describes a global structure optimization methodology for microelectromechanical system devices based on a multi-objective elitist genetic algorithm. By integrating a parameterized model with a multi-objective evolutionary framework, the approach can efficiently explore design space and concurrently optimize multiple metrics. A differential capacitive MEMS accelerometer is presented to demonstrate the method. Four key objectives, including resonant frequency, static capacitance, dynamic capacitance, and feedback force, are simultaneously optimized to enhance sensitivity, bandwidth, and closed-loop driving capability. After 25 generations, the algorithm converged to a uniformly distributed Pareto front. The experimental results indicate that, compared with the initial design, the sensitivity-oriented design achieves a 56.1% reduction in static capacitance and an 85.5% improvement in sensitivity. The global multi-objective optimization achieves a normalized hypervolume of 35.8%, notably higher than the local structure optimization, demonstrating its superior design space coverage and trade-off capability. Compared to single-objective optimization, the multi-objective approach offers a superior strategy by avoiding the limitation of overemphasizing resonant frequency at the expense of other metrics, thereby enabling a comprehensive exploration of the design space. Full article

The emerging paradigm of “fusion of lifeforms” represents a transformative shift from conventional human–machine interfaces toward deeply integrated symbiotic systems, where biological and artificial components co-adapt structurally, energetically, informationally, and cognitively. This review systematically classifies multi-level perception systems within fusion of lifeforms into four functional categories: sensory and functional restoration, beyond-natural sensing, endogenous state sensing, and cognitive enhancement. We survey recent advances in neuroprosthetics, sensory augmentation, closed-loop physiological monitoring, and brain–computer interfaces, highlighting the transition from substitution to fusion. Despite significant progress, critical challenges remain, including multi-source heterogeneous integration, bandwidth and latency limitations, power and thermal constraints, biocompatibility, and system-level safety. We propose future directions such as layered in-body communication networks, sustainable energy strategies, advanced biointerfaces, and robust safety frameworks. Ethical considerations regarding self-identity, neural privacy, and legal responsibility are also discussed. This work aims to provide a comprehensive reference and roadmap for the development of next-generation fusion of lifeforms, ultimately steering human–machine integration from episodic functional repair toward sustained, multi-level symbiosis between biological and artificial systems. Full article

This paper addresses Region-3 control of a 2.5 MW three-bladed HAWT using a data-driven workflow that links empirical modeling to implementable pitch control. To focus on fundamental regulation dynamics, the turbine is modeled as a rigid single-mass drivetrain driven by identified quasi-steady aerodynamics. First, we identify a compact shaft-power surface $P(\omega ,V,\beta )$ and recover the associated MPP condition, which clarifies why the optimal rotor speed rises with wind and motivates a comparison between capped-MPP operation and constant-speed regulation. We then synthesize a practical Region-3 loop—PI in rate with a first-order pitch servo and saturation handling—and evaluate proportional (P), PI, and PI + servo controllers under sinusoidal and Kaimal-turbulent inflow. Finally, we propose an adaptive PI variant that keeps a fixed acceleration feed-through but retunes the integral path online via ARX(1,1) + RLS to maintain a target closed-loop bandwidth. Performance metrics computed over the full simulation window (t ∈ [0, 50] s) show that P-only control exhibits large steady bias and cap violations; PI recenters speed and power around their targets; adding a pitch servo further trims peaks and ripple. In steady-state turbulent tests, PI + servo achieves tight regulation, Δω_peak ≈ 0.033% (0.079 rad/s), P_RMS ≈ 0.62%, while the adaptive PI maintains similar tightness with the lowest variability overall Δω_peak ≈ 0.0104% (0.025 rad/s), P_RMS ≈ 0.17. The workflow yields a practically implementable β(V) schedule and a lightweight adaptation mechanism that compensates for slow aerodynamic performance drift without changing the control structure. While structural loads and aeroelastic modes are not explicitly modeled, the proposed controller enforces strict speed and power constraints via a rigid-body dynamic analysis. Extensions to IPC, preview/forecast augmentation, and validation on higher-fidelity aeroelastic/drivetrain models are identified as future work. Full article

To mitigate rotor vibrations in magnetic bearing systems arising from mass imbalance, this study proposes a novel suppression strategy that integrates the crested porcupine optimizer (CPO) with an enhanced linear active disturbance rejection control (ELADRC) framework. The approach introduces a disturbance estimation and compensation scheme based on a linear extended state observer (LESO), wherein both the LESO bandwidth ${\omega }_0$ and the LADRC controller parameter ${\omega }_c$ are adaptively tuned using the CPO algorithm to enable decoupled control and real-time disturbance rejection in complex multi-degree-of-freedom (DOF) systems. Drawing inspiration from the crested porcupine’s layered defensive behavior, the CPO algorithm constructs a state-space model incorporating rotor displacement, rotational speed, and control current, while leveraging a reward function that balances vibration suppression performance against control energy consumption. The optimized parameters guide a real-time LESO-based compensation model, achieving accurate disturbance cancelation via amplitude-phase coordination between the generated electromagnetic force and the total disturbance. Concurrently, the LADRC feedback structure adjusts the system’s stiffness and damping matrices to improve closed-loop robustness under time-varying operating conditions. Simulation studies over a wide speed range (0~45,000 rpm) reveal that the proposed CPO-ELADRC scheme significantly outperforms conventional control methods: it shortens regulation time by 66.7% and reduces peak displacement by 86.8% under step disturbances, while achieving a 79.8% improvement in adjustment speed and an 86.4% reduction in peak control current under sinusoidal excitation. Overall, the strategy offers enhanced vibration attenuation, prevents current saturation, and improves dynamic stability across diverse operating scenarios. Full article

This study tackles real-time state estimation for autonomous underwater vehicle (AUV)–mobile docking station (MDS) cooperation over low-bandwidth, high-latency, jitter-dominated acoustic links, with the goal of turning delayed/out-of-sequence measurements (OOSM) into consistent and informative constraints without sacrificing online operation. We propose an integrated scheme centered on a delay-compensated extended Kalman filter (DC-EKF): a ring buffer enables backward updates and forward replay so that OOSM are absorbed strictly at their physical timestamps; a data-driven delay threshold is learned from “effective information gain” combined with normalized estimation error squared (NEES) filtering; and dynamic confidence, derived from innovation statistics, delay, and signal-to-noise ratio (SNR) proxies, scales the measurement noise to adapt fusion weights. Simulations show the learned delay threshold converges to about 6.4 s (final 6.35 s), error spikes are suppressed, and the overall position root-mean-square error (RMSE) is 5.751 m; across the full data stream, 1067 station measurements were accepted and 30 rejected, and the fusion weights shifted smoothly from inertial measurement unit (IMU)-dominant to station-dominant (≈0.16/0.84) over time. On this basis, a cooperative augmented EKF (Co-Aug-EKF) is added as a lightweight upper layer for unified-frame cooperative estimation, further improving relative consistency. The results indicate that the framework reliably maps delayed acoustic measurements into closed-loop useful information, significantly enhancing estimator stability and docking readiness, while remaining practical to deploy and readily extensible. Full article

To achieve high-frequency inductance and impedance enhancement for effective electromagnetic interference (EMI) mitigation in power electronics, this paper presents an electromagnetic analysis and experimental study of laminated Mn-Zn toroidal ferrite cores. The electromagnetic field is analyzed using a 2D analytical solution based on a simplified Cartesian approximation. Although neglecting curvature, this approach enables efficient eigenfunction expansion and is rigorously validated against cylindrical finite difference (FDM) and 3D finite element (FEM) benchmarks. The results demonstrate that lamination effectively interrupts eddy current loops; notably, a four-layer structure increases the resonant frequency by approximately 2.8 times compared to a monolithic core. Experimental measurements confirm that this design significantly mitigates the skin effect and extends the stable frequency bandwidth. This study establishes a validated, computationally efficient methodology for optimizing core geometries to prevent impedance degradation. Full article

This study presents the experimental optimization of an interferometric optical fiber sensor for acoustic emission (AE) detection. The system employs a simple and low-cost structure composed of sensing and reference fibers, enabling interference-based detection without specialized components such as fiber Bragg gratings or Fabry–Perot cavities. A narrowband laser source was selected through comparative experiments for its superior stability and interference performance. The influence of fiber-loop parameters, including the number of turns and the optical-path intensity ratio, was systematically evaluated to clarify their effects on AE sensitivity and frequency response. The experimental results demonstrate that detection performance and bandwidth can be flexibly tuned by optimizing the loop configuration. Finally, the sensor was validated using a tensile test, successfully detecting AE signals in the range of 20 kHz to 1 MHz. The proposed system provides a robust, EMI-resistant, and cost-effective interferometric solution for AE monitoring. Full article

We propose a compact, beaconless inter-satellite laser communication tracking system based on direct fiber control to address the complexity and resource demands of conventional pointing, acquisition, and tracking (PAT) architectures. Unlike traditional sensor-based or beacon-assisted schemes, the proposed method employs a piezoelectric ceramic tube (PCT) to generate high-frequency, small-amplitude nutation of the single-mode fiber (SMF) tip, enabling real-time alignment correction using only the coupled optical power of the communication signal. This fully closed-loop tracking approach operates without position sensors and eliminates the need for beam splitting, external beacon sources, or auxiliary position detectors. A theoretical model is developed to analyze the influence of algorithm parameters and optical spot jitter on dynamic tracking performance. Experimental results show that the closed-loop system reliably converges to the optical spot center, achieving a fine-tracking accuracy of 4.6 $\mathsf{\mu }$rad and a disturbance suppression bandwidth of 200 Hz. By significantly simplifying the terminal architecture, the proposed approach provides an efficient and SWaP-optimized solution for inter-satellite and satellite-to-ground optical communication links. Full article

This paper presents a 3-bit transmissive intelligent surface (TIS) using a novel technique that employs a unit cell comprising loaded semi-loop dipole resonators. The two resonators are anti-symmetrically oriented along the H-plane, functioning as transmitter and receiver on opposite sides of the TIS. The unit cell, with 13.2 mm periodicity, achieves 360° phase variation in 45° steps while maintaining insertion loss below 2 dB at 10 GHz. A 17 × 17 array TIS is designed using ray tracing and phase shift compensation techniques, with phase profiles distributed across eight discrete varactor states. The implemented TIS demonstrates a 10.8 dB gain enhancement for a horn antenna source at 10 GHz while preserving antenna matching, polarization, and radiation efficiency. The design achieves beam steering capabilities up to 60° with ±2° precision across elevation, azimuth, and inclined angles, maintaining an average steering gain loss of 3 dB over a 400 MHz bandwidth. These characteristics make the proposed design particularly effective for modern wireless coverage extension and tracking applications. Full article

A Q-enhanced notch filter for interference-rejection LNAs is proposed in this brief. The active capacitance is introduced into the notch filter to improve the quality factor by the negative resistance effect. The designed notch filter achieves excellent performance with a narrow attenuation bandwidth from 5.75 GHz to 5.95 GHz, which can be applied to suppress interference from the IEEE 802.11a. To validate the feasibility of the proposed trap filter in both GaAs process technology and principle, a 3–15 GHz ultra-wideband low-noise amplifier was designed and fabricated using a 0.15-micron gallium arsenide pseudomorphs field-effect transistor process. The frequency-dependent feedback loops are employed between gate and drain stages for wideband input matching and gain flatness. The notch filter is inserted between two stages of the LNA. The measurement results show that the interference-rejection LNA achieves a maximum gain of 24.5 dB and a minimum noise figure of 1.8 dB in the operating band. The notch filter has a maximum interference-rejection ratio of 35.2 dB at 5.8 GHz with almost no effect on the desired gain of the LNA. The LNA has a power consumption of 168 mW, including the notch filter with a size of 1.93 × 0.72 mm². Full article

The rapid expansion of IoT devices represents significant progress in areas such as smart buildings and smart cities, but at the same time, the volume of data generated represents a challenge, which can lead to real bottlenecks in the data analysis process, thus resulting in increased waiting times for end users. The use of cloud-based solutions may prove inefficient in some cases, as the bandwidth required for transmitting data generated by IoT devices is limited. The integration with Edge computing mitigates this issue, bringing data processing closer to the resource that generates it. Edge computing plays a key role in improving cloud performance by offloading tasks closer to the data source, optimizing resource allocation. Achieving the desired performance requires a dynamic approach to resource management, where task execution can be prioritized based on current load conditions: either at the Edge node or the Cloud node. This paper proposes an approach based on the Seasonal Auto Regressive Integrated Moving Average (SARIMA) model for seamlessly switching between the Cloud and Edge nodes in the event of a loss of connection between the Cloud and Edge nodes. Thereby ensuring the command loop remains closed by transferring the task to the Edge node until the Cloud node becomes available. In this way, the prediction that could underlie a command is not jeopardized by the lack of connection to the cloud node. The method was evaluated using real-world resource utilization data and compared against a Simple Moving Average (SMA) baseline using standard metrics: RMSE, MAE, MAPE, and MSE. Experimental results demonstrate that SRIMA significantly improves prediction accuracy, achieving up to 64% improvement for CPU usage and 35% for RAM usage compared to SMA. These findings highlight the effectiveness of incorporating seasonality and autoregressive components in predictive models for edge computing, contributing to more efficient resource allocation and enhanced performance in smart city environments. Full article

Ultra-high sampling rates in coherent optical front-ends increasingly exceed the processing capabilities of real-time baseband processors, creating a bottleneck in coherent free-space optical communication systems. We propose a unified state-space framework to systematically parallelize digital signal processing (DSP) algorithms. This approach transforms an algorithm’s transfer function into a state-space representation from which a parallel architecture is derived through matrix operations, overcoming the complexity of traditional ad hoc methods. Crucially, our framework enables an analysis of parallelization-induced latency. We introduce the parallel equivalent delay (PED) metric and demonstrate that it introduces right-half-plane zeros into the loop’s transfer function, thereby fundamentally constraining stability. This analysis leads to the derivation of “Throughput–Bandwidth Product” (TBP), a constant that provides a design guideline linking maximum stable loop bandwidth to the parallelization factor. The framework’s efficacy is demonstrated by designing a parallel Costas carrier recovery loop. Simulations validate its performance, confirm the TBP limit, and show significant advantages over conventional feedforward estimators, especially in low-SNR conditions. Implementation results on a AMD XCVU13P FPGA demonstrate that the proposed 50-parallel architecture achieves a throughput of 15.625 Gsps at a clock frequency of 312.5 MHz with a logic utilization below 7%. The experimental results confirm the theoretical trade-off between throughput and loop bandwidth, verifying the proposed design methodology. Full article

Second-order notch filters (NFs) with constant coefficients are often used as part of feedback controllers in grid-connected power conversion systems to prevent unwanted harmonic content polluting the closed control loops. In practice, the value of the mains frequency resides within a certain known range rather than remaining constant. Hence, the correct selection of NF coefficients is crucial for ensuring that the desired performance is maintained within the whole expected mains frequency range. Bilinear transformation (BLT) with notch frequency prewarping is often adopted to convert an NF from a continuous to a digital form. While accurately preserving the notch frequency location, the method reduces the filter bandwidth. As a remedy, BLT with both notch frequency and damping ratio prewarping may be employed. Nevertheless, some inaccuracy remains under low sampling-to-notch frequency ratios. This technical note demonstrates that the issue may be solved by prewarping the boundary values of the expected harmonic frequency range rather than the notch frequency and/or damping factor before applying the BLT. Simulation results accurately support the presented issue and proposed solution. Full article

The principle of non-Foster broadband matching of electrically small (high-Q) transmitting antennas has been around for more than a few decades. However, there have been only a handful of experimentally proven examples, with highly limited scope of application. The main obstacle is the inherent instability of non-Foster elements, since those are actually active circuits with positive feedback. This research investigates the idea that a common non-Foster transmitter antenna matching network can be replaced with the arrangement of multiple frequency-coherent sources, rendering positive feedback unnecessary. Two different approaches were analyzed, one with a coherent RF current source, the other one with a coherent voltage source. The viability of this idea has been verified by simulations and experimental results. Unlike non-Foster matching, the proposed principle cannot support instability because it does not contain any positive feedback loops. In addition, it offers multiple-octave operational bandwidth, while the efficiency is limited only by the linear operation of the used circuitry, thus remaining at least equal to that of its non-Foster equivalent. While the proof-of-concept experiments were conducted in the lower HF (up to 20 MHz) frequency band, where common antennas are electrically small and highly reactive, there are no physical obstacles to scaling the same principle of operation to higher frequencies. Full article

This study presents a high-speed, 9-bit integrating-mode phase interpolator (IMPI) in a 12 nm FinFET process. The proposed slew-rate-tolerant design accepts bandwidth-limited inputs, relaxing the stringent need for high-slew-rate clocks found in prior research. This is primarily achieved through an optimized switch design that converts the sinusoidal voltage input into a quasi-square-wave current. A detailed theoretical model identifies asymmetrical clock feedthrough as the dominant nonlinearity, which is suppressed by a cancellation circuit. Furthermore, an adaptive biasing loop is employed to compensate for Process, Voltage, and Temperature (PVT)-induced P/N mismatch. This work is validated through comprehensive post-layout simulations; operating from a 0.8 V supply at 16 GHz, the PI achieves a peak-to-peak Integral Nonlinearity (INL) of 4.3 LSB (530 fs) while consuming 6.56 mW. Full article