Search Results (1,510)

This paper presents a multi-frequency electro-thermal Digital Model framework for accurate mapping and prediction of near-field electromagnetic (EM) power dissipation and localized temperature rise in high-frequency planar microwave structures. The proposed methodology integrates 3D full-wave computational simulations in CST Studio Suite with non-invasive transient infrared (IR) thermography using an Indium Tin Oxide (ITO) coated Polyethylene Terephthalate (PET) thin-film transducer. A high-gain 4 × 4 microstrip patch antenna array operating nominally at 12.00 GHz serves as the experimental benchmark. Numerical and physical evaluations were conducted across five discrete operating frequencies (7.10, 8.05, 9.05, 11.14, and 12.00) GHz at near-field evaluation distances of 1 mm, 16 mm, and 29 mm under a continuous-wave microwave (MW) excitation over a 50 s exposure duration. Transient surface temperature dynamics were recorded using a calibrated Teledyne FLIR A700 LWIR radiometric sensor. Quantitative line profile validation yields an average maximum temperature rise error of 20.75%, an average spatial center shift of 2.70 mm, and an average spatial spread (FWHM) deviation of 21.29%. These moderate discrepancies are physically attributed to evaluating free-space electric field intensity (|E|²) within the numerical domain versus measuring resistive heat generation on the physical ITO film. The developed Digital Model framework provides a robust foundation for real-time thermal monitoring, localized hotspot suppression, and predictive thermal management in advanced phased arrays and high-power MW systems. Full article

Complex scalar kernels often contain instruction fragments whose computation is simple but whose operand demand exceeds the traditional two-input–one-output custom-instruction model. This operand interface bottleneck limits instruction merging in tightly coupled RISC-V acceleration. This paper proposes a multi-operand extension mechanism based on a Preload-Compute-Store architecture, which widens the operand interface over time instead of increasing the register-file read-port count. The mechanism combines U4S/D-type interface instructions, data preloading, and an output buffer to support up to six input operands and five output operands while keeping the changes to the original pipeline localized. The design was implemented in the Verilog hardware description language on Western Digital’s open-source VeeR EH1 processor core and evaluated on a Xilinx Artix-7 field-programmable gate array (FPGA) using cryptographic hashing and digital filtering kernels. Cycle-count speedups reach up to 1.15× on the hashing kernels, whereas the filtering workload gains only marginally, and part of the gain is offset by a reduction of less than 4% in the achievable clock frequency; the extension itself costs less than 2% in look-up tables and flip-flops. These results show that operand interface width is a practical constraint on tightly coupled custom-instruction acceleration, and that the mechanism is most useful for scalar fragments with sufficient operand pressure. Full article

The growing demand for precise unmanned aerial vehicle (UAV) operations in dynamic environments is often compromised by unmodeled wind disturbances, calling for robust and adaptive control strategies to ensure accurate trajectory tracking. This paper presents a meta-learning augmented model predictive control (ML-MPC) framework for quadrotor trajectory tracking under strong and horizontal wind disturbances with different nominal wind-speed settings. The framework uses a meta-learned basis function to capture shared nonlinear features of aerodynamic disturbances across different wind-speed conditions, while an online adaptation mechanism continuously estimates the corresponding coefficients from flight data. Their combination provides a real-time estimate of the residual aerodynamic force, which is incorporated into the MPC prediction model to compensate for wind disturbances. Extensive flight experiments validate the effectiveness of the ML-MPC framework, showing consistent gains in tracking accuracy across multiple trajectory types and under nominal wind-speed settings of up to $16\mathrm{m}/\mathrm{s}$, defined by measurements $1\mathrm{m}$ downstream of the fan array. Compared to a baseline GP-MPC controller, the approach achieves average performance improvements of 73.5% in simulation and 50.6% in real-world flight tests, with maximum reductions of 86.5% and 59.7%, respectively. Full article

Background/Objectives: Invasive micropapillary carcinoma (IMPC) of the breast is a rare subtype with a strong propensity for lymph node metastasis, but its molecular features remain incompletely defined. We characterized the genomic and transcriptomic features of breast carcinomas with an invasive micropapillary component. Methods: Thirteen tumors with a micropapillary component of at least 10%, including four pure IMPCs, were analyzed by targeted sequencing (n = 11), whole-exome sequencing with array comparative genomic hybridization (n = 2), and whole-transcriptome sequencing (n = 9). Alteration frequencies were compared with TCGA-BRCA across all 375 panel genes, with multiple-testing correction and a sensitivity analysis restricted to truncating and hotspot variants. Results: TP53 was the most frequently altered gene (72.7%), followed by ERBB2 amplification (45.5%); PIK3CA and GATA3 were each altered in 27.3%. Four rarely mutated genes were more frequent than in TCGA-BRCA after correction, but these differences were based on few tumors and predominantly on uncertain missense variants and were not retained under the stringent definition. Recurrent high-level amplification was concentrated in 17q12-q21, and both pure IMPCs analyzed by array comparative genomic hybridization showed 8q gain. All five tumors with panel ERBB2 amplification were HER2-positive by immunohistochemistry, and TCGA-anchored PAM50 classified all three HER2-positive transcriptomes as HER2-enriched. Fourteen fusion transcripts were detected, none recurrent. Conclusions: These findings support a heterogeneous molecular landscape characterized by established breast cancer drivers, recurrent copy-number changes involving 8q and 17q, predominantly private fusion events, and cross-platform concordance of ERBB2 amplification with HER2 protein expression and PAM50 HER2-enriched classification. Full article

To address the performance degradation of traditional adaptive beamforming algorithms in low signal-to-noise ratio (SNR) marine environments, a weighted nuclear norm minimization optimized minimum variance distortionless response beamformer (WNNM-MVDR) is proposed. The method integrates low-rank matrix processing with beamforming and applies singular-value-dependent weighting to the sample covariance matrix, thereby retaining dominant signal components while suppressing noise-subspace components. The shrinkage parameter is initialized using a random-matrix-theory estimate of the upper edge of the noise spectrum. Simulation and sea-trial results evaluate the method under limited snapshots, array mismatch, varying SNRs, and coherent multipath. Under ideal conditions without array mismatch and with sufficient snapshots, the algorithm consistently achieves an output SNR gain of more than 4 dB for input SNRs above −20 dB. Sea-trial results further show a 1.68 dB output SNR improvement over conventional MVDR, a 2.67 dB extension of the practical weak-target detection limit, and reliable robustness to array-position errors up to 0.204 wavelengths. These results indicate that WNNM-MVDR can improve adaptive beamforming performance in the marine scenarios considered here. Full article

This paper proposes a circularly polarized (CP) antenna array featuring high aperture efficiency, a low in-band radar cross section (RCS), and a low profile. First, two different patch antenna elements are designed, which exhibit desirable CP performance and a 180° reflection phase difference under x-polarized normal incidence within the same operation band. These elements are then arranged in a chessboard configuration to simultaneously achieve high aperture efficiency and in-band RCS reduction under x-polarized normal incidence. Subsequently, the parasitic units are uniformly embedded into the array elements, which are employed to realize reflection phase cancellation with the array elements under y-polarization normal incidence. The simulated results show that the proposed array achieves a peak monostatic RCS reduction of 12.8 dB, and the 6 dB RCS reduction bandwidth fully covers the antenna’s operating bandwidth under both x- and y-polarized normal incidences. Moreover, the gain of the antenna array reaches 18.2 dBic at 3 GHz with an aperture efficiency of 58% and a profile of 0.03λ. A good agreement is obtained between the simulated and measured results. This design successfully combines the advantages of high aperture efficiency, dual-polarized in-band RCS reduction, and a low profile, making it highly valuable for aerospace satellite communications and unmanned aerial vehicle data links. Full article

The ultra-high data rate and ultra-reliable low-latency communication (URLLC) requirements of Industry 4.0 and smart factory applications have made the evaluation of Sub-Terahertz (Sub-THz) frequencies, especially the 140 GHz band, in sixth-generation (6G) wireless networks a considerable research area. Nevertheless, modern literature often makes isotropic assumptions that do not account for the extreme free-space path loss and highly metallic obstacles associated with sub-THz frequencies. To solve this problem, this paper suggests a comprehensive framework combining high-gain directional antenna design with deterministic 3D ray-tracing channel characterization in a realistic industrial environment. Principally, an optimized 140 GHz 4 × 4 high-gain antenna array system was designed and numerically modeled using CST Studio Suite, and its active element pattern (AEP)-based synthesized 3D radiation pattern was then incorporated into a MATLAB-based Shooting and Bouncing Ray (SBR) tool for a more realistic simulation of the antenna system. Procedural generation of a 3D synthetic model of a smart factory, containing metallic obstacles like Computer Numerical Control (CNC) machines, shelving units, and autonomous guided vehicles (AGVs), was conducted to represent the deterministic multipath environment. Path loss, Power Delay Profile (PDP), RMS Delay Spread, and angular dispersion (Angle of Arrival (AoA) and Angle of Departure (AoD)) analysis prove effective for spatial filtering. Despite significant non-line-of-sight (NLoS) obstructions, leading to 106.5 dB of path loss and a high azimuth angle of arrival spread of 82.9°, the design provides a zero outage in the targeted sector of operation. At the same time, directional beamforming tightly controls the azimuth angle of departure spread to 6.5° and RMS delay spread of 21.5 ns. The results demonstrate that using a realistic antenna radiation pattern is critically important. Furthermore, they reveal multipath behavior in complex industrial scenarios and provide vital insights for the deployment of 6G industrial Internet of Things (IIoT) networks. Full article

Steel slag, rich in free CaO/MgO, calcium silicates, and calcium ferrites, suits engineering, boosting alkaline solid waste and carbonating CO₂ minerals. However, studies interpret CO₂ sequestration capacity differently. Metrics like CO₂ sequestration capacity, mass gain, and carbonate content are lumped as capture measures, blocking cross-study comparison and inconsistent carbonation assessments. The study rigorously evaluates seven conventional measurement techniques: thermogravimetric analysis, mass gain measurement, gas consumption monitoring, acid digestion method, elemental analysis, combustion-infrared absorption spectrometry, and X-ray diffraction, thoroughly discussing their quantifiable targets, relevant scopes, systematic biases, and failure scenarios. Representative data show 7-day CO₂ sequestration values of 6.5–10.2 g CO₂/100 g initial sample across four analytical routes; stepwise-TG, tangential-TG, combustion-infrared AD-TIC, and acid-digestion HT-TIC gave 9.0, 6.5, 10.2, and 9.7 g CO₂/100 g, respectively, corresponding to a highest-to-lowest spread of 3.7 g CO₂/100 g (36.3% of the highest value). Analytical findings indicate that variances among testing techniques arise not only from arbitrary measurement errors but mainly from differences in specific carbon pools, protocols for sample pre-treatment, criteria for identifying carbonate species, categorization of gas–liquid–solid phase limits, and methods for assessing statistical uncertainty. Consequently, this document suggests a quadruple-tiered evidence chain structure, encompassing the material background, process mass equilibrium, product-associated carbon measurement, and statistical fusion layers. An array of functional standards has been formulated, encompassing the removal of background baselines, confirmation of mass closure, four-point cross-validation, and broadened reporting of uncertainties. The suggested model converts the measurement of steel slag’s carbon capture ability from isolated, singular measurements to a system that is traceable, confirmable, and verifiable with multiple evidence sources. This offers strong methodological backing for large-scale lab experiments, expanding processes, confirming carbon emission reductions, and developing uniform testing procedures. To improve operational clarity, the framework explicitly distinguishes background solid inorganic carbon, newly mineralized stable solid carbon, liquid-phase dissolved inorganic carbon, physically retained CO₂, and crystalline carbonate carbon; it also introduces quantitative decision bands for mass closure and cross-method agreement and demonstrates reconciliation using a published multi-method BOF steel-slag dataset. Full article

Partially connected hybrid analog-digital beamforming architectures substantially reduce the hardware cost and power dissipation of massive antenna arrays by routing multiple antenna elements to a single radio-frequency (RF) chain. In contested or dense electromagnetic environments, however, strong directional interference entering low-resolution analog-to-digital converters (ADCs) increases signal-dependent quantization distortion and can exceed the converter range if gain control is inadequate. To overcome this fundamental bottleneck, this paper develops a quantization-aware hybrid anti-interference receiver for partially connected architectures constrained by finite-resolution phase shifters and low-bit ADCs. The proposed receiver operates in three coordinated stages. In the spatial sensing stage, the receiver sequentially applies multiple pseudo-random analog combining configurations to collect compressed spatial observations, and reconstructs the angular power spectrum of unknown interference sources via an additive quantization noise model (AQNM)-corrected nonnegative sparse covariance fitting problem solved by the fast iterative shrinkage-thresholding algorithm (FISTA). In the analog beamforming stage, using the reconstructed interference-plus-noise covariance, subarray analog combiners are optimized directly on the complex constant-modulus manifold via Riemannian gradient descent and mapped to discrete phase states, forming analog spatial nulls to reduce interference before quantization. In the digital combining stage, a diagonally loaded robust minimum variance distortionless response (R-MVDR) combiner is formulated directly on the quantized RF domain to suppress residual interference and tolerate covariance estimation errors. Comprehensive simulations demonstrate that the proposed receiver improves output signal-to-interference-plus-noise ratio (SINR) relative to the evaluated hybrid baselines, maintaining substantial performance advantages over conventional hybrid beamforming baselines across diverse interference powers, ADC bit depths (3–8 bits), coarse phase quantization (3–8 bits), reduced RF chain counts, and limited snapshot budgets. Full article

This paper presents two antenna array designs, an equal-phase array and a monopulse array, implemented using dielectric 3D-printing technology. To achieve wideband operation and low back-lobe radiation, a novel magneto-electric dipole (ME-dipole) element is first proposed. This element is derived from an open-ended waveguide; the open aperture functions as a magnetic dipole, while a pair of metallic patches placed at the aperture forms an electric dipole. Through structural evolution, the element is adapted for post-processing after 3D printing. The two arrays are then developed using this element. The equal-phase array employs a three-stage cascaded T-junction feeding network, whereas the monopulse array replaces the first-stage T-junction with a Magic-T coupler. The main bodies of both arrays are printed from dielectric material, and selected surfaces are copper-electroplated to form the necessary metallic components. The proposed arrays offer simple fabrication, low weight, and good performance. Measurements show that the equal-phase and monopulse arrays achieve overlapped bandwidths of 32.8% and 35.6% and peak gains of 13.1 and 13.5 dBi, respectively. The measured null depth of the monopulse array is below −32.3 dB. Full article

Cellular substrates placed beneath the piezoceramic are increasingly used to raise the output of vibration energy harvesters, yet the enhancement is commonly attributed to auxeticity, and the durability penalty of perforation is seldom quantified. This paper presents a perforated-root piezoelectric cantilever in which a doubly periodic array of bow-tie (double-arrowhead) through-holes occupies the high-curvature root beneath the electrode while the distal span remains solid. Using a cell of positive effective Poisson’s ratio, we show that power gain is a substrate-compliance and strain-relocation effect set by the position of the perforation relative to the electrode rather than by a negative Poisson’s ratio. A segmented distributed-parameter model in which the perforated root is homogenised and enters the beam through its longitudinal effective modulus $E_1^{*}$, with the piezoelectric coupling reduced to its plane-stress value, is derived and tested against three independent finite-element measurements on the explicit hole geometry in ANSYS Parametric Design Language (APDL). Two agree closely: a direct axial-tension test returns $E_1^{*}/E_s=0.270$ against 0.268 predicted (0.7%), and the substrate-only fundamental is 21.7 Hz against 21.5 Hz predicted (1.0%). The third does not: with the piezoceramic present, the reduction predicts 47.7 Hz against 36.4 Hz, so the absolute frequency of the complete device is not yet established, and only the trends are relied upon here. At equal overall dimensions and piezoceramic, the baseline cell raises the peak power by about 14% over the solid beam, from 38.6 to 44.0 μW, and lowers the resonance from 57.6 to 50.7 Hz; both effects grow with hole size, reaching 23% and 46.5 Hz at the largest cell examined. A fatigue-constrained formulation, in which the net-section ligament stress bounds the usable fill factor, caps the fill at $f\approx 0.59$ under a 1 g excitation and yields a fill factor–load design map for durable operation. Full article

Mosaic trisomy 14 is a rare chromosomal anomaly with a broad phenotypic spectrum. We report a 10-year-3-month-old girl with severe short stature, developmental delay, and repaired patent ductus arteriosus. An incompletely documented combined insulin–clonidine stimulation test yielded a peak GH concentration of 6.85 ng/mL and was not considered sufficient to establish growth hormone deficiency. Karyotyping of 100 peripheral-blood metaphases showed 47,XX,+14[6]/46,XX[94]. Initial copy-number sequencing detected a 34.37 Mb mosaic 14q gain; repeat SNP-based chromosomal microarray analysis demonstrated an approximately 86.83 Mb 14q11.2-q32.33 mosaic gain at an array-estimated fraction of approximately 50%, compatible with the cytogenetic diagnosis. Targeted 14q32.2 analysis showed increased total and methylated-allele dosage, with methylated fractions of 48.6–62.3%, interpreted as dosage imbalance within the broader 14q gain rather than an independent epimutation. Four STR loci showed biparental inheritance. Quantitative peak-height and peak-area analysis at three informative, bias-correctable STR loci demonstrated excess paternal-allele dosage, providing independent support for, but not definitive proof of, paternal origin of the additional chromosome 14. rhGH was prescribed for SGA with persistent short stature at 0.22 mg/kg/week. At three months, height was 124.7 cm (+1.9 cm); no adverse events were reported. These observations do not establish treatment efficacy or safety. Full article

Coherent signal synthesis among multiple remote apertures is a fundamental challenge for next-generation distributed radar and communication systems, and its performance hinges on the precision of the frequency and time references shared by the distributed nodes. In this work, we report a system-level study of a microwave-photonics-based frequency synchronization system that phase-locks two independent signal sources over a 40 km fiber link, and we validate the resulting coherent beamforming and power combining capabilities of the synchronized pair. The synchronization link, built on an adaptive phase-locked loop with dispersion compensation, delivers a frequency stability of $8.0\times {10}^{-15}$ at 1 s and $2.0\times {10}^{-16}$ at 1000 s. Using the synchronized pair, we perform beam-scanning and beamforming experiments in a microwave anechoic chamber at 1–7 GHz. The measured beam-pointing angles agree with theoretical predictions, and a coherent gain enhancement of 5.9 dB is obtained with a gain loss below 0.1 dB. Furthermore, field tests with a 150 m free-space separation between the two transmitting antennas confirm stable coherent signal synthesis, with the combined amplitude maintained within 1 dB over extended periods. Beyond the specific experimental results, we apply the known gain-loss relation to derive an engineering guideline relating the frequency stability of the synchronization link to the achievable coherent gain loss. These results show that an established microwave-photonics synchronization technology, when integrated with standard signal sources, provides a practical route toward distributed coherent arrays for long-range detection and wideband communication. Full article

This work presents a spatial multi-feed beam steering reflectarray concept intended for compact small satellite payloads with adapted field of view (FoV) coverage. Unlike conventional reflectarray beam steering approaches based on tunable unit cells or mechanical reconfiguration, the proposed approach exploits the controlled displacement of the phase center of a digital planar feed array to illuminate a passive reflectarray surface from different spatial positions, enabling beam steering without tunable unit cells or mechanical reconfiguration. First, the beam steering mechanism is analyzed through the phase gradients induced by feed displacement, including the impact of amplitude illumination and incidence angle-dependent unit cell response. Then, the concept is experimentally validated at 30 GHz using a developed reflectarray and a 2 × 2 patch array feed repositioned over a multi-position interface to emulate overlapping subarrays of a virtual 4 × 4 feed array. The measured radiation patterns show good agreement with simulations, confirming the predicted beam pointing trends with measured gains between 26.57 and 27.91 dBi for the evaluated subgroups. Finally, a mission-oriented architecture for the UPMSat-4 scenario is analyzed, considering a reflectarray surface up to 600 mm × 400 mm integrated into solar panels and a 16-element linear array feed. The results demonstrate the feasibility of generating a linear multibeam FoV, achieving beam overlap and a minimum carrier-to-noise ratio (C/N) of approximately 32 dB in the considered link budget scenario. The proposed architecture provides a scalable and low-complexity alternative for flexible smallsat antenna payloads. Full article

In photovoltaic-based hybrid energy storage systems (PV–HESS), rapid power transients accelerate battery degradation, directly reducing the operating lifetime and sustainability of renewable power resources. To address this issue, the current study proposes an optimal coordinated framework for the simultaneous and coordinated tuning of battery and supercapacitor current-loop proportional–integral (PI) controllers. The proposed framework treats the four PI gains of the battery and supercapacitor controllers as a unified optimization problem, applying five metaheuristic algorithms: Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Gazelle Optimization Algorithm (GOA), Artificial Protozoa Optimizer (APO), and White Shark Optimization (WSO). The optimization problem is directly coupled with a full nonlinear MATLAB 2022b/Simulink PV–HESS model, capturing the dynamic interactions among the PV array, bidirectional converters, DC-link capacitor, storage units, and load. A combined Integral of Time-weighted Absolute Error (ITAE) objective function is used to minimize current tracking errors, ensuring the supercapacitor absorbs fast power fluctuations while shielding the battery from high-frequency thermal and electrical stress. The controllers are evaluated across four operating scenarios involving steady irradiance shifts, rapid irradiance fluctuations, load disturbances, and a simultaneous irradiance drop from 1000 W/m² to 400 W/m² with a 33% load increase. The results confirm stable DC-link regulation and effective power sharing. Specifically, APO delivers superior performance in the high-stress scenario, GOA minimizes transient-error indices, and GA achieves the lowest DC-link voltage RMSE. These findings demonstrate that coordinated tuning effectively balances high-frequency dynamics, extending battery service life and enhancing the long-term operational sustainability of solar microgrid storage. Full article