Search Results (1,581)

To address the issue that multipath effect severely restricts the performance of indoor visible light positioning (VLP) systems and multipath interference intensity varies significantly across different regions, this paper proposes a spatial adaptive multipath suppression scheme for the first time. At the transmitter, a hybrid transmission architecture of time division multiplexing (TDM) and direct current biased-orthogonal frequency division multiplexing (DCO-OFDM) is employed, providing ideal observation vectors for sparse channel modeling at the receiver through specialized pilot symbol design. At the receiver, a novel Spatial Adaptive–Main Path Energy Constraint–Orthogonal Matching Pursuit (SA-MPEC-OMP, SMO) algorithm is proposed to adapt to the spatial region characteristics with varying multipath intensities, enabling low-latency and accurate separation of Line-of-Sight (LOS) and Non-Line-of-Sight (NLOS) paths. Simulation results verify that the SMO algorithm achieves high main path extraction accuracy exceeding 90% in all regions, with its LOS energy ratio 2.7 to 3 times higher than that of the traditional OMP algorithm. Based on the results of the multipath suppression scheme, a high-precision 3D VLP scheme is proposed by integrating the SMO multipath suppression with intelligent algorithms. Specifically, a point classification model performs regional partitioning and dynamic threshold matching, while a height estimation model driven by LOS power extracted via SMO estimates the height of the target point. Finally, 3D coordinates are calculated using trilateration. Simulation results indicate that through the synergy of signal design and algorithm optimization, the proposed scheme achieves centimeter-level positioning across the entire space with a single positioning time of less than 18.7 ms, featuring strong multipath robustness and promising engineering application potential. Full article

Single-Event Burnout (SEB) is one of the most critical failure mechanisms in silicon power MOSFETs operating in radiation environments, particularly under heavy-ion irradiation, and often limits device operation through excessive voltage derating. In this work, SEB robustness of a silicon VDMOS power device is investigated using detailed electro-thermal transient simulations. The study evaluates two complementary device-level modifications: the introduction of a buffer layer between the epitaxial layer and the substrate, which has been reported in the past, and a new approach considering the incorporation of a novel highly doped boron BOX implant within the P-body region. Heavy-ion impacts are simulated using a physically based model implemented in SENTAURUS TCAD, accounting for ion energy deposition, impact position, and thermal effects. The results show that the buffer layer increases the second breakdown voltage and can suppress high-current operating points, while the BOX implant raises the parasitic BJT activation threshold by reducing the P-body resistance. When combined, both modifications lead to a significant reduction in the peak temperature reached during after-impact transients, without introducing measurable degradation of static electrical characteristics. These results demonstrate that combining buffer layer engineering with localized P-body resistance reduction is an effective strategy to improve SEB robustness in silicon VDMOS power devices without relying on excessive derating. Full article

Ionospheric delay is a dominant error source in global navigation satellite systems (GNSSs). Conventional ionospheric estimation relies on dense networks of expensive geodetic receivers, limiting accessibility and coverage. With the widespread availability of multi-frequency, multi-constellation smartphones capable of carrier-phase tracking, this study investigates smartphone-based ionospheric estimation. Using a single-reference Precise Point Positioning Real-Time Kinematic (PPP-RTK) framework, ionospheric delays are estimated from smartphone data and evaluated using real-time correction products from BeiDou PPP-B2b and Centre National d’Études Spatiales (CNES). Quality control is performed via solution separation testing with time-differenced carrier phase and time-differenced pseudorange. Field experiments with two Google smartphones and a geodetic receiver demonstrate that the estimated slant ionospheric accuracy is comparable to geodetic receivers within the meter level under both static and kinematic scenarios. Additionally, the horizontal positioning performance demonstrates that the positioning performance of the user smartphone with ionospheric corrections broadcast from the base smartphone is significantly improved, with 74.7% and 54.9% for CNES and PPP-B2b products compared with the conventional PPP solution. Furthermore, a comparison between ionospheric corrections generated from the smartphone and those obtained from the geodetic receiver reveals that the positioning performance of the user smartphone becomes comparable after convergence. Full article

The revitalization of vitality in historic cultural districts can enhance a city’s cultural attractiveness and promote the upgrading of the urban cultural industry and sustainable development. Revealing the threshold and synergistic effects of different districts’ scene elements on district vitality helps to identify the distribution patterns of district vitality and provides a basis for managerial decision-making. This study first uses a geographic information system (ArcGIS) to overlay Baidu heatmaps with the street-network distribution in order to depict the spatiotemporal heterogeneity of district vitality and to compute vitality values by partitions at the district scale. Subsequently, based on an explanatory framework that integrates the physical space and subjective cognition, multi-source data such as street-view panoramas and points of interest (POIs) are quantified to obtain scene-element values for each unit area. Then, the scene-element values and vitality values are integrated into a consolidated database. Additionally, the LightGBM model and the SHAP method are employed to evaluate each element’s marginal contribution and relative importance to district vitality, thereby screening out the key scene elements. Finally, by means of SHAP dependence plots and interaction-effect analysis, the threshold intervals of the key elements and their synergistic relationships are identified, revealing the nonlinear threshold effects and synergies by which scene elements influence spatial vitality. The results show that during rest days, district vitality exhibits stronger diffusion, and the synergistic effect between Leisure-Facility Attractiveness and Street-Network Accessibility is the most prominent in enhancing vitality. High Exhibition-Facility Attractiveness is difficult to sustain crowds on its own; only when Leisure-Facility Attractiveness is likewise high does its effectiveness increase significantly. When Transport Accessibility is within the 0.20–0.40 interval, the positive effect of Leisure-Facility Attractiveness is significantly amplified. An excessive Traditional–Modern Facility Mix readily leads to homogenization of districts; therefore, when introducing modern business formats, local cultural characteristics must be retained. Overall, the generation of district vitality relies more on the synergy between material factors and subjective cognition than on improvements to any single element. The findings of this study provide suggestions for the planning of scene elements and the enhancement of vitality in historic cultural districts. Full article

Background: Floating barbed threads are commonly used for minimally invasive midface lifting and rely on mobile subcutaneous tissue for support, which may limit stability. Fixation is primarily achieved by barb engagement within the subcutaneous fat and fibrous septa of the retinacula cutis. Objectives: To describe an anatomically guided modification of the APTOS Excellence Visage Soft (PLLA/PCL) thread technique, positioning the terminal segment posterior to the zygomatic retaining ligament line with the aim to enhancing mechanical stability. This technical report presents the anatomical rationale, procedural steps, and illustrative clinical cases demonstrating feasibility. Methods: The modified technique uses a single-entry point at the superior zygomatic margin, with five threads per hemiface. After linear insertion, the cannula is rotated laterally and inferiorly to position the terminal barbs posterior to the zygomatic retaining ligament line, thereby transferring tensile load toward a more fixed anatomical structure. Representative cases were documented and are presented. Results: Illustrative cases showed immediate midface elevation with improved malar projection and softening of the nasolabial and mentolabial folds. Standardized 3D imaging and vector analysis demonstrated a superolateral pattern of soft tissue displacement along the intended vectors, consistent with the proposed fixed-anchorage concept. The procedure was well tolerated, with only mild and transient local effects observed. One illustrative case included photographic follow-up at 12 months, in which preservation of midface contour and malar projection was visually appreciable. Conclusions: Redirecting the terminal thread segment posterior to the zygomatic retaining ligament line is a feasible modification that may contribute to improved vector stability by engaging a fixed fascial structure. Observations—including one case with 12-month follow-up—support the anatomical plausibility of the approach, although controlled studies with objective endpoints are necessary to confirm long-term efficacy and reproducibility. Full article

This practice-led research examines how virtual production represents a circular return to scenographic practice, reactivating integrated modes of spatial authorship that have long underpinned screen storytelling but were obscured by industrial fragmentation. Drawing on a single-day intensive workshop at the Australian Film, Television and Radio School (AFTRS), the study analyses how spatial authorship emerged through embodied, collaborative engagement with an LED volume environment. Grounded in scenographic theory and concepts of distributed cognition and situated authorship, the article reframes virtual production as a condition that renders pre-digital, collaborative modes of making visible within contemporary screen production. The LED volume functions simultaneously as scenic environment, lighting instrument, and compositional partner, requiring participants to negotiate space, light, movement, and camera as a unified spatial event. Analysis identifies how scenographic understanding emerged through virtual scouting, world-responsive storytelling, physical-digital integration, and embodied realisation. The findings extend production design theory by challenging ocular-centric models of mise-en-scène and positioning scenographic integration as screen practice—an epistemic mode of enacting through collective, materially grounded spatial experimentation. While situated within an educational context, the study points to broader implications for how spatial authorship and collective practice are understood in contemporary screen production. Full article

This study numerically investigates the NO removal performance of a staged catalyst substrate employed in an industrial marine after-treatment system. The computational domain is based on the lab-scale experimental device used for measuring pressure drop, serving as a digital twin to accurately reproduce the staged catalyst configuration prior to its application in full-scale industrial reactors. Experiments were conducted to estimate the parameters for a porous model, employed for efficient computation of flow and reactive mass transfer inside the catalyst substrate without needing a complex computational mesh of the monolith structure. A reaction mechanism from the literature was modified and verified for marine SCR reactors. The three-dimensional numerical simulations in this study indicate that the NO removal in the staged catalyst substrate varies depending on the catalyst configuration, primarily due to differences in the upstream flow uniformity. This study demonstrates that relocating a single catalyst substrate to the downstream position improved conversion by 6.5 percentage points, while a two-stage catalyst configuration yielded a 15.5 percentage-point increase under identical exhaust conditions. In addition, the residence time exhibited significant variations depending on the catalyst arrangement and inlet velocity, highlighting it as a critical parameter governing NO reduction performance. The findings in the present study can serve as a reference for future analyses conducted under practical conditions in industrial-scale marine SCR systems. Full article

Tetanus toxin evaluation has traditionally relied on mouse LD₅₀ bioassays, which require extensive animal use and time, necessitating development of alternative methods in accordance with 3R principles (Replacement, Reduction, and Refinement). We developed and validated a sandwich enzyme-linked immunosorbent assay (ELISA) as an alternative to animal testing for evaluating tetanus toxin biological activity using 18 environmental and clinical isolates of Clostridium tetani, complemented by an immunochromatographic (IC) assay for rapid screening. The ELISA demonstrated excellent analytical performance with a lower limit of quantification of 2.4 ng/mL (equivalent to 85.4 LD₅₀/mL), favorable linearity (R² = 0.999), precision (CV < 1.7–8.2%), and specificity (<1% cross-reactivity with C. septicum, C. novyi, and C. perfringens). Correlation analysis between ELISA relative potency and observed minimum lethal dose values revealed a robust positive correlation (r = 0.974). Both parallel line assay and single-point quantification methods showed strong correlations with mouse bioactivity measurements (r = 0.998). The IC assay successfully detected all isolates within 15 min. The measurement range of 2.4–45.6 ng/mL effectively covered diverse toxin-production capabilities spanning a 600-fold concentration range. This validated ELISA and IC assay combination provides a reliable, rapid alternative to animal experimentation for tetanus toxin evaluation. Full article

Cylinders are common in both industrial and daily settings. Accurate geometric fitting of their parameters, including position, orientation, and radius, is important in real-world perception tasks and industrial applications. At present, consumer-level RGB-D cameras provide three-dimensional (3D) point cloud data with acceptable accuracy and are widely adopted in various sensing applications. Consequently, this task is typically formulated as a geometric fitting problem based on point cloud data. However, point cloud data acquired from such sensors often contain noise, particularly when scanning curved surfaces, which directly degrades the performance of point cloud-based fitting methods. In this paper, we propose an edge–point cloud fusion approach for the geometric fitting of cylinder parameters from single-view RGB-D data. Our approach leverages two-dimensional (2D) image-domain edge constraints together with point cloud data, then fuses them in a unified formulation to jointly optimize cylinder parameters. By explicitly incorporating reliable edge information, our method effectively mitigates the effects of noise in point cloud data. We evaluate the proposed method using real-world RGB-D data, and the experimental results show that our approach achieves significant improvements in both accuracy and robustness. Full article

This study formulates a deterministic model to assess the effect of a family-based control and management (FBCM) strategy against the transmission of Helicobacter pylori infection and its consequent development of gastric ulcers and gastric cancer. The model includes nine epidemiological compartments to model disease transmission and contact epidemiology between susceptible and infected individuals. In the model analysis, we compute positivity, the invariant region, equilibria, stabilities, and bifurcation analysis. We calculate the control reproduction number ${\mathcal{R}}_0$ and demonstrate that the model has a unique disease-free equilibrium (DFE) and an endemic equilibrium point (EEP) that are locally and globally stable for ${\mathcal{R}}_0<1$ and ${\mathcal{R}}_0>1$, respectively. We perform a thorough mathematical analysis and validate the model by fitting it to real data on gastric cancer cases recorded at Meru Teaching and Referral Hospital, Kenya. The best numerical results are achieved when we combine both preventive measures (sensitization and a family-based approach) and curative measures (prompt treatment and adherence), resulting in the greatest decrease in gastric ulcer and gastric cancer cases compared with a single intervention. This study shows that integrated household-level interventions can reduce transmission and prevent mild-to-severe disease progression through effective sensitization campaigns, high FBCM efficacy, effective gastric ulcer treatment, and adherence to drug protocols. The use of such strategies offers an effective means of reducing Helicobacter pylori-related gastric ulcers and gastric cancer outcomes, with important implications for public health control program design. Full article

Intravenous delivery of recombinant adeno-associated virus serotype 9 can lead to reporter activation in cell types beyond the vasculature, but the routes enabling downstream parenchymal labeling remain unclear. Here, we provide a systematic, time-resolved map of parenchymal labeling after a single intravenous dose of rAAV9 encoding Cre recombinase under a ubiquitous promoter in healthy adult Ai9 reporter mice. Following retro-orbital administration, we quantified tdTomato-positive labeling across 25 targets at multiple time points over six months and observed durable reporter activation in several nonvascular parenchymal populations relevant to systemic gene-delivery applications. We also identify a set of parenchymal cell types that are consistently labeled in both this vascularly initiated reporter system and our prior adult VE-cadherin-driven reporter paradigm, supporting a connection to vascular exposure without asserting lineage relationships. These results nominate mechanistic routes for future disambiguation, including viral transcytosis across endothelium, endothelial cell transdifferentiation and extracellular-vesicle-mediated transfer. The dataset and methods provide a reference framework for investigators optimizing systemic delivery and interpreting downstream labeling in vivo. Full article

The accurate estimation of tree canopy volume is fundamental in precision agriculture for quantifying vegetation structure, biomass, and productivity in perennial cropping systems. This study investigates a shadow geometry approach for estimating olive tree canopy volumes from a single, very high-resolution WorldView-3 multispectral image. The method integrates multispectral classification for canopy and shadow delineation with a geometric model that infers canopy height from shadow measurements, accounting for solar position and terrain morphology. Two classification strategies were evaluated: object-based image analysis (OBIA) and pixel-based (PB) classification, each applied to the original eight-band multispectral image and to a derived dataset enriched with vegetation indices (NDVI—Normalized Difference Vegetation Index; NDRE—Normalized Difference Red Edge Index) and principal component analysis (PCA) components. The canopy volume was estimated by integrating classified canopy and shadow areas with shadow-derived canopy height. The methodology was tested in a Mediterranean olive orchard and validated against UAV-derived point clouds for approximately 700 trees. The results indicate that the approach captures spatial variability in canopy structure. The Object-Based Image Analysis (OBIA) applied to filtered PCA-enhanced imagery achieved the highest accuracy in canopy volume estimation (RMSE = 2.04 m³; R² = 0.56), outperforming the alternative pixel-based (PB) classification applied to the original multispectral data. Overall, the study demonstrates the potential of single-image WorldView-3 data for rapid and scalable three-dimensional canopy characterization in precision agriculture. Full article

Most existing research in human pose estimation focuses on predicting joint positions, paying limited attention to recovering the full 6D human pose, which comprises both 3D joint positions and bone orientations. Position-only methods treat joints as independent points, often resulting in structurally implausible poses and increased sensitivity to depth ambiguities—cases where poses share nearly identical joint positions but differ significantly in limb orientations. Incorporating bone orientation information helps enforce geometric consistency, yielding more anatomically plausible skeletal structures. Additionally, many state-of-the-art methods rely on large, computationally expensive models, which limit their applicability in real-time scenarios, such as human–robot collaboration. In this work, we propose STAG-Net, a novel 2D-to-6D lifting network that integrates Graph Convolutional Networks (GCNs), attention mechanisms, and Temporal Convolutional Networks (TCNs). By simultaneously learning joint positions and bone orientations, STAG-Net promotes geometrically consistent skeletal structures while remaining lightweight and computationally efficient. On the Human3.6M benchmark, STAG-Net achieves an MPJPE of 41.8 mm using 243 input frames. In addition, we introduce a lightweight single-frame variant, STG-Net, which achieves 50.8 mm MPJPE while operating in real time at 60 FPS using a single RGB camera. Extensive experiments on multiple large-scale datasets demonstrate the effectiveness and efficiency of the proposed approach. Full article

Over the past two decades, the term cervical incompetence has largely been replaced by cervical insufficiency in clinical guidelines, reflecting efforts to avoid pejorative language and to acknowledge functional variability. However, despite this terminological evolution, the underlying conceptual framework has remained largely static, continuing to treat cervical insufficiency as a fixed anatomic defect inferred from obstetric history or single-point measurements. This Perspective argues that such a model inadequately explains the substantial clinical heterogeneity observed across and within pregnancies, limiting its usefulness for individualized clinical interpretation and study design. Drawing on contemporary guideline frameworks, systematic reviews, and international disease classification systems, this article highlights the limitations of static, anatomy-centered approaches and proposes an alternative conceptualization of cervical insufficiency as a dynamic, pregnancy-specific vulnerability. Within this framework, cervical behavior is understood as time-dependent and context-sensitive, shaped by the interplay of mechanical load, biological processes, and gestational timing rather than predetermined structural failure. This conceptualization is intended to inform interpretation across diverse clinical contexts, rather than to redefine diagnostic criteria or existing guideline recommendations. By shifting emphasis from fixed diagnostic labels to trajectories of cervical vulnerability, this Perspective situates cervical insufficiency within the broader continuum of spontaneous preterm birth and aligns its interpretation with the principles of personalized medicine. This conceptual reframing positions cervical insufficiency as a model condition for personalized maternal–fetal care, emphasizing time- and context-aware risk assessment and trajectory-informed clinical decision-making, while providing a coherent foundation for individualized surveillance and future research aimed at improving maternal–fetal outcomes. Full article

Purpose: The present study aimed to assess the radiation dose associated with low-dose (LD) CT pelvimetry compared with conventional radiography and to evaluate the adequacy of the resulting image quality. Methods: The absorbed dose was measured using thermoluminescent dosimeters positioned in an anthropomorphic female phantom, including uterine locations, to estimate the fetal dose. Conventional radiographic pelvimetry and LD-CT pelvimetry were performed using clinically implemented protocols. Effective dose was calculated using Monte Carlo–based modeling applying acquisition parameters and retrospective patient dose registry data. Image quality of LD-CT pelvimetry was independently evaluated in 14 consecutive clinical cases using a four-point ordinal scale. Results: LD-CT pelvimetry reduced the mean absorbed pelvic dose by approximately 50% compared with conventional pelvimetry (0.18 vs. 0.39 mGy) and decreased estimated fetal dose by 40% (0.21 vs. 0.37 mGy). These estimates were based on standardized single acquisitions and did not incorporate additional radiation from retakes commonly observed in conventional practice. CT demonstrated substantially more homogeneous dose distribution, whereas conventional pelvimetry exhibited marked heterogeneity with peak values up to 2.3 mGy. The maternal effective dose was lower for LD-CT (0.16 mSv) than for conventional pelvimetry (0.36 mSv); inclusion of retakes increased the conventional effective dose to 0.71 mSv. All CT examinations were diagnostically adequate, and no recalls were required. Conclusions: Optimized low-dose CT pelvimetry significantly reduces radiation dose compared with conventional radiographic pelvimetry while maintaining reliable diagnostic image quality. These results support the clinical adoption of CT-based pelvimetry as a dose-efficient and reproducible alternative to conventional techniques. Full article