Search Results (590)

Reconfigurable intelligent surfaces (RIS) equipped with extremely large aperture arrays (ELAA) are emerging as a key technology for enhancing beamforming gain, spatial multiplexing, and angular resolution in sixth-generation (6G) wireless networks. When combined with non-orthogonal multiple access (NOMA), RIS can further improve spectral efficiency, system throughput, and energy efficiency. However, most existing studies on RIS-aided NOMA assume far-field propagation, where the incident wavefronts are approximately planar. In contrast, RIS-ELAA systems operating at millimeter wave (mmWave) experience spherical wavefronts in the radiative near-field regions. Also, it creates spatial non-stationarity and distance-dependent phase curvature. These effects invalidate the conventional monotonic path-loss assumption and make fairness-oriented NOMA design more challenging. This paper proposes a joint element and power optimization (JEPO) algorithm for near-field RIS-ELAA-assisted indoor NOMA systems, in which the RIS is dynamically partitioned into user-specific subarrays performing near-field phase synthesis toward the near user (NU) and far user (FU). The reversed far-to-near successive interference cancellation (SIC) ordering, governed by an effective FU channel gain greater than an effective NU channel gain, is formally established, and a closed-form optimal power allocation is derived by reducing the max-min fairness condition to a scalar quadratic in the target signal-to-interference-plus-noise ratio (SINR), eliminating iterative power search. Simulation results confirm that JEPO consistently outperforms four baseline schemes across transmit power, NU distance, angular separation, and RIS aperture size, with the largest gain observed at ${\theta }_{\mathrm{NU}}\approx {40}^{\circ }$ where fixed-partition baselines collapse to near-zero fairness while JEPO maintains robust performance. Full article

The fragmentation of clinical information across health systems, community pharmacies, and specialty providers continues to undermine medication safety and emergency care, particularly when patients are unconscious or otherwise unable to communicate their history. The dominant response to this fragmentation has been the construction of a centralized data infrastructure—health information exchanges, prescription drug monitoring programs (PDMPs), and federated electronic health record (EHR) networks—that aggregates clinical information into institutional databases that are queryable by providers, insurers, regulators, and, in many jurisdictions, law enforcement. This article argues that the same care-coordination problems can be addressed through an architecturally different approach in which the patient, not the institution, holds the integrative artifact. The proposed design, here labeled the Guardian Card (a conceptual architecture, not a commercial product), pairs an HL7 Fast Healthcare Interoperability Resources (FHIR) clinical payload with the SMART Health Cards verifiable-credential framework and a dual-modality (QR code plus near-field communication) physical carrier. After describing the technical architecture, hardware options, and a five-phase deployment roadmap, the design is situated within the surveillance-critical scholarship that has documented PDMP function creep, third-party doctrine erosion, racial disparities in algorithmic prescribing oversight, and the surveillance-instrumentarian repackaging of nominally de-identified prescription data. The Guardian Card is offered as one operational implementation of a patient-controlled medication-record architecture, with community pharmacy and long-term post-acute care, where the Pharmacist eCare Plan integration is most feasible as a recommended first-deployment venue. Full article

Wildfires in California increasingly threaten communities and ecosystems. However, comprehensive estimation of fire dynamics and fuel structure remains limited. Recent advances in Uncrewed Aerial Vehicle (UAV) technology and high-spatial-resolution mapping have provided increasingly important tools for estimating wildfire fuel-height loss across fuel types. This study used a one-year Uncrewed Aerial Vehicle (UAV) time series to quantify fuel-height loss and vegetation regrowth associated with a prescribed upslope canyon fire near Salinas, California, USA. Multispectral, infrared, and visible UAV imagery collected before, during, and after burning was used to generate orthomosaic, digital surface models (DSMs), fuel-type classifications, and surface-volume estimates. To enable reliable pre- and post-fire comparison, ground control points and tie points were used to train linear regression calibrations that corrected angular discrepancies and elevation offsets among time-series DSMs. Calibrated DSMs were then integrated with ecological field measurements to map fuel-height consumption and post-fire recovery at the individual-plant scale. UAV-derived fuel-height change was associated with in situ twig-diameter measurements, which provide field-based indicators of fire effects in chaparral vegetation, while the maximum recorded temperature explained only a small proportion of variation in fuel-height loss. This workflow can support integrated fire ecology and remote-sensing studies by providing repeatable measurements of post-fire changes in vegetation structure. Full article

This paper investigates a near-field millimeter-wave (mmWave) integrated sensing and communication (ISAC) system under unknown interference. A base station equipped with a partially connected dynamic subarray hybrid architecture serves a legitimate user while performing target-oriented transmit beampattern shaping. Unlike existing works that assume perfect interference knowledge, we characterize the unknown interference channels via a robust spatial covariance uncertainty model. To exploit spatial degrees of freedom for interference suppression, the user employs a fully connected hybrid receiver. We formulate a robust transmit power minimization problem subject to worst-case communication signal-to-interference-plus-noise ratio (SINR) and sensing beampattern constraints, alongside constant-modulus and dynamic subarray hardware constraints. To solve this highly non-convex mixed discrete–continuous problem, we propose a two-layer alternating optimization framework. The inner layer optimizes the continuous and phase-quantized beamformers using successive convex approximation, while the outer layer refines the binary subarray connections via a penalty-augmented local discrete search. Extensive simulations demonstrate that explicitly modeling worst-case uncertainties ensures reliable ISAC performance in adversarial environments, and the dynamic subarray architecture systematically outperforms conventional fixed topologies in power efficiency. Additional robustness and sensitivity analyses show that these gains are most pronounced when sufficient spatial degrees of freedom remain, whereas excessive antenna failures, unmodeled strong multipath, or covariance drift outside the uncertainty envelope can erode the communication and sensing margins. Full article

Wireless-power mobile edge computing, SWIPT-MEC, priority-aware WPT scheduling and swarm resource allocation already solve important parts of the energy-management problem. The novelty of WPT-JCCO is not any one of those elements; it is a single swarm-supervisory feasible set that couples decisions which the three adjacent method classes normally separate. Each epoch-level action jointly selects the robot to charge and one of three physically distinct WPT modalities: far-field radio-frequency, resonant near-field and directional lightwave transfer, together with the SWIPT split, local/edge task placement, CPU frequency, bandwidth and transmit power. Relative to SWIPT-MEC, the formulation adds discrete recipient–modality selection with pose, alignment, blockage and dwell-dependent feasibility. Relative to conventional WPT scheduling, charging is not a separate priority or routing stage but is solved jointly with computation and radio allocation. Relative to swarm resource-allocation methods, energy replenishment is endogenous and an individual minimum-battery constraint protects the weakest robot. A fourth coupling makes the centrally generated resource vector admissible only when the complete sense–compute–actuate age fits the one-second supervisory epoch; otherwise a previously feasible or local-safe action is applied. Nonlinear harvesting, partial offloading, priority scoring and augmented-Lagrangian primal–dual updates are treated as established techniques. This paper derives the continuous block updates, keeps the WPT variables binary through candidate screening, and declares convergence only when stationarity, feasibility, merit-change and binary-hold tests are jointly satisfied. Normalised primal steps are safeguarded by backtracking, dual and penalty updates are bounded, and a local tracking bound plus divergence monitor delimit real-time operation without claiming global mixed-integer optimality or closed-loop motion stability. Numerical evaluation over a 20-robot swarm and 30 Monte Carlo runs shows that WPT-JCCO reduces net energy depletion by 23.8% relative to communication–computation optimisation with static WPT and by 49.7% relative to local-only execution, while increasing task success from 93.5% to 97.3%. A released common-trace comparison shows normalised-cost reductions of 11.1%, 11.3% and 5.8% relative to two-stage WPT+CCO, fixed-SWIPT dynamic offloading and an offline Q-learning scheduler. Convergence and one-factor-at-a-time sensitivity studies further examine swarm size, task load, WPT budget, bandwidth, edge capacity, mobility and channel margin. The headline values remain scoped to the nominal independent-task case; mode-specific RF, near-field and lightwave operating envelopes, robust pose/CSI, WPT-safety and task-DAG extensions are formulated but not presented as hardware-validated results. Full article

The deployment of large-scale antenna arrays (ELAAs) in sixth-generation (6G) networks extends wireless communications into the near-field regime, facilitating integrated sensing and communications while introducing security requirements. To ensure secure near-field transmission and sensing accuracy, this paper proposes a framework that jointly minimizes the Cramér–Rao Bound (CRB), guarantees quality-of-service (QoS) for ordinary users, and ensures the covertness of a primary user through an explicit vulnerable-region constraint. The nonconvex problem is addressed through an iterative approach integrating semidefinite relaxation (SDR), alternating optimization (AO), and successive convex approximation (SCA). Numerical results demonstrate sensing performance, QoS satisfaction, and accurate vulnerable-region control. Full article

This study investigates an IPS-type Metglas/PMN-PT laminated magnetoelectric composite and its feasibility as a reciprocal mechanical magnetoelectric antenna for low-frequency transmission and reception. Finite-element simulations under quasi-static and frequency-domain conditions reveal strong magnetoelectric coupling under an optimal DC bias field, with both the direct magnetoelectric effect (DME) and converse magnetoelectric effect (CME) exhibiting pronounced resonance near 14.5 kHz, governed by the same longitudinal extensional vibration mode. Five IPS samples were fabricated and experimentally characterized. All devices showed resonant frequencies within 14.1–14.5 kHz, peak DME coefficients of 3.0 × 10⁶ to 3.9 × 10⁶ pC/Oe, and peak CME coefficients of 12.0~15.8 Oe·cm/V, confirming good fabrication consistency, transmit–receive reciprocity, and array-integration potential. The parallel IPS antenna generated a magnetic flux density of 37 nT at 1 m, and exhibited an equivalent magnetic noise of 63 fT/Hz^1/2 at 14.45 kHz. These results demonstrate that the proposed IPS structure combines high-sensitivity reception with efficient low-frequency transmission, showing strong potential for miniaturized, low-power, and long-range magnetic communication and underwater communication applications. Full article

Laser-induced acoustic communication is a highly adaptable cross-medium technique that combines the advantages of optical transmission through air and acoustic transmission underwater. However, poor signal stability at high repetition frequencies currently hinders its widespread application. To address this, this paper proposes an innovative scanning focal-point method to enhance stability. Traditional methods such as beam scanning, focus control, and distributed interaction are primarily aimed at enhancing sound pressure in a specific direction, achieving near-field/far-field focusing, or improving the signal-to-noise ratio through coherent synthesis of ultrasonic intensity. In contrast, the method proposed in this paper is intended to avoid the interference of droplets and vapor generated by single-point breakdown under high repetition frequencies, which would otherwise degrade the laser-acoustic conversion efficiency. It is therefore an active defense strategy specifically targeting the stability of laser-induced acoustic communication. First, optical simulation software was used to analyze the effects of surface ripples and bubbles on focal spot displacement and size. Next, a single-pulse experimental system was developed to measure the range and duration of surface depressions caused by optical breakdown. Finally, a scanning focal-point system was constructed for comparative experiments, with results recorded via hydrophones and high-speed cameras. The maximum laser-induced acoustic signal generated by the scanning focal-point method is 7.4 times that produced by single-point breakdown. The experimental results demonstrate that the scanning focal-point method can effectively avoid the influence of water surface disturbance and steam on the optoacoustic conversion efficiency and significantly improve the amplitude and stability of the laser-induced acoustic signal. Full article

During atmospheric reentry, a spacecraft is enveloped by a turbulent plasma sheath that induces severe signal degradation and communication blackout. Conventional mitigation strategies primarily focus on reducing average attenuation but fail to address the dynamic fluctuations in plasma density (typically 20–40%), which cause significant group velocity dispersion (GVD), pulse broadening, and intersymbol interference. To overcome this limitation, this paper proposes an active decoupling framework that dynamically tunes an external magnetic field to suppress turbulence-induced signal distortion in the reentry plasma sheath. By establishing a wave propagation model for right-hand circularly polarized (RCP) waves in magnetized collisional plasma and introducing a sensitivity analysis of propagation parameters with respect to plasma density fluctuations, we derive the condition under which the first-order sensitivity of GVD vanishes. Under this condition, a dynamic balance between collisional effects and frequency detuning renders the system immune to density perturbations, effectively decoupling signal transmission from plasma turbulence. Numerical simulations demonstrate that, under optimal parameter matching satisfying the dispersion immunity condition ($\mathsf{\Delta }{\omega }_0^2=3{\nu }_e^2$), pulse broadening can be suppressed by several orders of magnitude, and the broadening factor remains near unity over extended propagation distances. It is further shown that this optimal condition is highly sensitive to plasma parameter evolution, motivating the necessity of adaptive magnetic field control in dynamically evolving reentry environments. This work provides a novel physical-layer paradigm for mitigating reentry blackout by actively decoupling signals from turbulence via dynamically tuned magnetic fields. Full article

Coastal lagoons are increasingly affected by altered salinity regimes due to river diversion and hydrological regulation, with major impacts on ecosystem structure and functioning. The Venice Lagoon is a paradigmatic case, where centuries of river diversion have reduced freshwater inputs, causing widespread marinization and the decline of brackish habitats such as reedbeds (Phragmites australis). Within the LIFE Lagoon Refresh project, controlled freshwater inputs from the Sile River (300–1000 L s⁻¹ since 2020) were reintroduced into the Ca’ Zane Valley to restore salinity gradients. Vegetation responses were assessed by comparing pre-diversion (2018) and post-diversion (2024) conditions across 28 salt marsh platforms (9.82 ha) using field surveys, UAV imagery, satellite data and GIS analysis. Both freshwater inflow, which reduced salinity from values > 30 psu to mean values of 0.22 and 5.6 psu near the canal inlet and within a few hundred meters, respectively, and reed transplants triggered rapid changes in plant communities. Hypersaline species such as Salicornia procumbens subsp. veneta, Limonium narbonense, and Sarcocornia fruticosa declined, while brackish species such as Galatella tripolium and Phragmites australis expanded, reaching up to 75% cover in areas with salinity < 10 psu. These findings demonstrate that controlled freshwater inflows and transplants of suitable species can represent an effective nature-based solution for the sustainable restoration of coastal lagoons, habitat diversity, ecosystem functionality, biodiversity conservation, and long-term resilience to environmental change. Full article

Frequent engineering changes in manufacturing require worker instructions to be updated quickly and reliably. In many production environments, however, update handling still depends on manual comparison procedures, delayed communication, or repeated traversal of large document collections, limiting responsiveness during ongoing production changes. This paper presents a hierarchical hash-based method for change detection in structured manufacturing documents as the computational core of a worker assistance system for near-real-time instruction updates in the context of in-line qualification. Heterogeneous instruction data are transformed into canonical hierarchical document structures, from which SHA-512 digests are generated at multiple structural levels. During repeated comparison operations, document-state evaluation is reduced to digest comparison, while structural differences can be localized through hierarchical refinement of affected substructures. The method is integrated into a system architecture that combines predecessor-linked version management with role-specific filtering for controlled dissemination of relevant instruction updates. The approach was implemented in an automotive assembly use case involving structured work instructions and evolving production documentation. The evaluation demonstrates that the proposed approach reduces repeated comparison effort relative to conventional field-wise traversal methods while maintaining the ability to localize structural changes through hierarchical refinement. The reported results focus on computational behavior and implementation feasibility in structured manufacturing environments rather than hardware-specific throughput benchmarks. Overall, the results indicate that hierarchical comparison of structured instruction states provides a practical basis for change-aware worker assistance and controlled propagation of instruction updates in evolving manufacturing environments. The evaluation focuses on repeated-comparison scenarios in structured manufacturing settings and does not address semantic interpretation of detected changes or large-scale distributed deployments. Full article

The switch in land use of abandoned tailings can precondition their reuse as newly built parks. This study investigated the feasibility of reusing a remediated mercury (Hg) retorting site in Wanshan, Guizhou Province, China, as a functional urban park by assessing residual heavy metal risks and associated vegetation responses. Field investigations were conducted across 31 park sites distributed along an east–west geographical gradient from the former mining area to urban parks, using replicated plots to sample the surface soils and dominant plant species. The concentrations of arsenic (As), cadmium (Cd), mercury (Hg), manganese (Mn), and lead (Pb) in soil and plant tissues were quantified using inductively coupled plasma–mass spectrometry, and vegetation structure and diversity were evaluated using standard community indices. The results showed significant spatial variability in soil and plant metal concentrations, with higher levels generally observed near historically impacted areas of the mine. However, all soil metal concentrations were below the national safety thresholds. Plant tissues exhibit controlled metal accumulation within normal or regulated ranges, reflecting the effective screening of tolerant and hyperaccumulating species. Increasing heavy metal concentrations were associated with reduced vegetation coverage, height, and diversity along the gradient. Overall, the findings indicate that the reclaimed Hg retorting site almost met ecological safety requirements, but more data on deep soils, groundwater, and long-term observations are needed to draw more conclusive conclusions. Full article

Ground deformation monitoring is critical for safety and environmental management in modern mining. Active mining sites are highly exposed to terrain instabilities and subsidence, risking infrastructure integrity, disrupting operations, and posing hazards to communities. In this context, Differential Synthetic Aperture Radar Interferometry (DInSAR) techniques provide an effective and non-invasive tool capable of detecting millimetric surface displacements. This study implements the Small Baseline Subset (SBAS) technique through an open-source workflow based on the Python package hyp3_sbas, enabling semi-automated and reproducible interferometric processing by combining HyP3 with MintPy. The workflow is applied to the Björkdal gold mine (Sweden), a pilot site of the Horizon Europe XTRACT project focused on enhancing resilience in critical raw material supply chains. Integrating Sentinel-1 viewing geometries resolves the true vertical deformation field, yielding an overall mean velocity of −3.99 mm/year across the mining complex, with significant displacement rates concentrated below the 25th percentile (Q1) at −11.07 mm/year. Sector-specific analysis reveals localised subsidence accelerating over underground footprints and tailings storage facilities (mean velocities of −6.56 and −3.98 mm/year; Q1 thresholds near −13.00 mm/year), contrasting with the geomechanical stability observed at the open-pit area (mean: −0.45 mm/year). The proposed open-source framework shows strong potential for operational satellite-based monitoring, supporting predictive maintenance and early-warning strategies for risk management in mining environments while simplifying and standardising the interferometric processing workflow. Full article

The 5G Wireless and Wireline Convergence (5G-WWC) standards introduce critical network functions—notably the Access Gateway Function (AGF) and the User Plane Function (UPF)—to enable unified wired and wireless access through a single 5G core. However, deploying and integrating these functions across heterogeneous programmable hardware platforms remains a significant open architectural challenge. This paper presents a configurable integration framework that orchestrates AGF and UPF workloads on heterogeneous programmable data planes, specifically NVIDIA BlueField-2 Data Processing Units (DPUs) and P4-based switches. Unlike traditional, hardware-specific implementations, the framework provides a unified control plane that dynamically manages AGF-only, UPF-only, or Combined AGF/UPF deployments. A hardware abstraction mechanism decouples the control logic from pipeline-specific details, enabling the same control plane to drive different underlying hardware without modification. A Generic Flow Rule interface standardises communication between the control plane and each user-plane backend, while a merged DPU pipeline for Combined AGF/UPF eliminates the redundant GTP-U encapsulation and decapsulation steps inherent in a naively cascaded design. Experiments on NVIDIA BlueField-2 DPUs achieve near-100 Gbps throughput across all three TR-470 scenarios (AGF-only, UPF-only, and Collocated AGF/UPF). The Combined AGF/UPF configuration exhibits lower end-to-end latency than the separated AGF + UPF configuration, confirming both the feasibility and the efficiency of the proposed framework for next-generation high-performance programmable networks. Full article

Heterostructured metals and alloys are designed with spatial variations in strength and hardening that produce synergy beyond the rule of mixtures. This review surveys face-centered cubic (FCC), body-centered cubic (BCC), and hexagonal close-packed (HCP) systems, including architectures formed or modified by rolling and related severe plastic deformation routes, and examines them under tension, compression, and shear. Across material classes, mechanical incompatibility between hetero-zones drives stress partitioning and plastic strain gradients that store geometrically necessary dislocations near zone boundaries. The associated internal back and forward stresses sustain work hardening, delay instability, and influence localization and damage initiation. We evaluate continuum, crystal plasticity, dislocation-based mesoscale, and atomistic approaches by whether they predict these internal fields and whether they are validated against internal-field measurements. Key observations are that predictive models require physically identifiable intrinsic length scales, experimentally constrained interface laws, and careful separation of mechanisms to avoid double-counting when gradient and kinematic terms coexist. Major gaps remain in parameter identifiability for multi-zone and nonlocal formulations, in transferability across processing routes and loading modes, and in community benchmarks that couple well-characterized microstructures with multimodal measurements. Recommendations are provided for validation targets and benchmark campaigns to accelerate predictive design. Full article