Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (1,777)

Search Parameters:
Keywords = non-local means

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
23 pages, 2480 KB  
Article
Transfer Learning from Homogeneous to Heterogeneous: Fine-Tuning a Pretrained Interatomic Potential for Multicomponent Mo Alloys with Localized Substitutional Alloying
by Lixin Fang, Liqin Qin, Limin Zhang, Hao Zhou, Xudong He, Zekun Ren, Tongyi Zhang and Yi Liu
Materials 2026, 19(9), 1715; https://doi.org/10.3390/ma19091715 - 23 Apr 2026
Abstract
Machine learning interatomic potentials (MLIPs) are typically developed for globally ordered homogeneous systems (GOHomS), which exhibit only minor local deviations from equilibrium configurations. Consequently, most existing MLIPs trained on GOHomS often perform inadequately when applied to locally ordered heterogeneous systems (LOHetS), e.g., substitutional [...] Read more.
Machine learning interatomic potentials (MLIPs) are typically developed for globally ordered homogeneous systems (GOHomS), which exhibit only minor local deviations from equilibrium configurations. Consequently, most existing MLIPs trained on GOHomS often perform inadequately when applied to locally ordered heterogeneous systems (LOHetS), e.g., substitutional alloying elements in multicomponent alloys. To describe doping alloy systems, we develop a fine-tuned MLIP based on the MACE foundation model, specifically tailored for Mo-based dilute alloys containing one or two out of 20 substitutional elements: Cr, Fe, Mn, Nb, Re, Ta, Ti, V, W, Y, Zr, Al, Zn, Cu, Ag, Au, Hg, Co, Ni, and Hf. The model is built on more than 7000 equilibrium and non-equilibrium structures derived from first-principles density functional theory (DFT) calculations. The optimized large-scale fine-tuned model attains state-of-the-art accuracy, with a mean absolute error (MAE) and root-mean-square error (RMSE) of 2.27 meV/atom and 3.79 meV/atom for energy predictions, and 13.83 meV/Å and 24.26 meV/Å for force predictions, respectively. Systematic evaluation under different data-splitting protocols shows that unknown element extrapolation remains challenging under strict dopant hold-out, whereas substantially improved accuracy can be achieved in partial-exposure transfer settings. The fine-tuned models reduce the MAE by approximately 7–10 times compared to models trained from scratch, and by 10–20 times relative to zero-shot foundation models. This performance gain remains consistent across varying dataset sizes (equilibrium vs. non-equilibrium structures) and model scales. Our work illustrates the efficacy of transfer learning from globally ordered homogeneous systems to locally ordered heterogeneous multicomponent alloy environments. However, direct transfer to entirely unknown elements remains challenging, especially when proxy embeddings are employed without fine-tuning. Thus, to achieve high accuracy without incurring additional cost, it is essential to include unknown elements in the training dataset while minimizing the number of configurations containing known elements. Moreover, the current findings are primarily validated for dilute Mo-based alloy systems. Extending this approach to more compositionally complex alloy spaces may necessitate additional data and further fine-tuning. Full article
(This article belongs to the Section Metals and Alloys)
18 pages, 270 KB  
Article
Post-Migration Dietary and Lifestyle Transitions and Chronic Disease Risk Among African Migrants in Australia: A Case of Nigerian Migrants
by Kingsley Arua Kalu, Muideen Olaiya, Nse Odunaiya and Blessing Jaka Akombi-Inyang
Nutrients 2026, 18(9), 1327; https://doi.org/10.3390/nu18091327 - 22 Apr 2026
Abstract
Background: Migration from low- and middle-income to high-income settings is often accompanied by dietary and lifestyle changes that may increase long-term risk of non-communicable diseases. African migrants represent a growing but under-studied population in Australia, with limited evidence on post-migration nutrition transitions and [...] Read more.
Background: Migration from low- and middle-income to high-income settings is often accompanied by dietary and lifestyle changes that may increase long-term risk of non-communicable diseases. African migrants represent a growing but under-studied population in Australia, with limited evidence on post-migration nutrition transitions and associated chronic disease risk. This study examined changes in diet and lifestyle among Nigerian-born adults before and after migration to Australia and explored any association with chronic diseases. Methods: A pilot cross-sectional study was conducted among adults who migrated from Nigeria to New South Wales, Australia, between 1992 and 2019. Data were collected via a culturally adapted, self-administered online questionnaire assessing socio-demographic characteristics, dietary intake, lifestyle behaviours, and self-reported chronic conditions in the 12 months immediately before and after migration. Descriptive statistics (frequencies and proportions) and inferential analyses (Chi-square tests, McNemar test, and the Bowker test) were used to compare pre- and post-migration behaviours and examine associations with chronic disease outcomes. Results: Ninety-three participants completed the survey (mean age 37.0 ± 7.2 years; 50.5% male). Post-migration, regular breakfast consumption declined (−24.3%), while irregular eating (low and moderate) patterns increased (+7.6% and +16.7%). Regular vegetable intake improved (+5.4%), whereas fruit intake remained low (13.0%). Regular consumption of Nigerian local foods decreased markedly (−53.7%), while regular intake of meat (+18.5%), dairy foods, fats (+14.3%), and non-alcoholic beverages increased (+22.8%). Salt use shifted away from the highest-risk category (−22.2%), and smoking and alcohol consumption remained low and stable. Self-reported chronic conditions were uncommon; hypertension (6.5%) and obesity (5.4%) were the most frequently reported. Conclusions: Nigerian migrants in Australia experience substantial post-migration dietary and lifestyle transitions that may elevate long-term chronic disease risk despite a currently low reported disease burden. Early, culturally responsive nutrition and lifestyle interventions are needed to support healthy adaptation and prevent the progression of cardiometabolic conditions in this growing migrant population. Full article
(This article belongs to the Section Nutrition and Public Health)
27 pages, 19340 KB  
Article
Integrating Surface Deformation and Ecological Indicators for Mining Environment Assessment: A Novel MDECI Approach
by Lei Zhang, Qiaomei Su, Bin Zhang, Hongwen Xue, Zhengkang Zuo, Yanpeng Li and He Zheng
Remote Sens. 2026, 18(9), 1272; https://doi.org/10.3390/rs18091272 - 22 Apr 2026
Abstract
Surface subsidence induced by underground coal mining is a primary driver of ecological degradation. The traditional Remote Sensing Ecological Index (RSEI), however, struggles to capture surface deformation constraints and vegetation response lags. To address this, we developed a Mining Deformation–Ecology Coupling Index (MDECI). [...] Read more.
Surface subsidence induced by underground coal mining is a primary driver of ecological degradation. The traditional Remote Sensing Ecological Index (RSEI), however, struggles to capture surface deformation constraints and vegetation response lags. To address this, we developed a Mining Deformation–Ecology Coupling Index (MDECI). This index integrates Interferometric Synthetic Aperture Radar (InSAR)-monitored surface stability with multi-spectral indicators via Principal Component Analysis (PCA). We applied this method to the Datong Coalfield, China, using 231 Sentinel-1A SAR scenes and 8 Landsat images (2017–2024) to validate the effectiveness of the index. Meanwhile, we systematically analyzed non-linear response mechanisms, the Ecological Turning Point (ETP), and spatial clustering characteristics. The results demonstrate the following: (1) InSAR and MDECI effectively identified patterns of surface subsidence and ecological decline. Subsidence centers expanded to a maximum of −2085 mm, causing the mean MDECI in these areas to drop to 0.185 (<−1800 mm). This represents a 57.4% decrease relative to the regional average (0.434). (2) MDECI outperformed traditional models with a stable Average Correlation Coefficient (ACC) (0.63–0.75) and high cross-correlation coefficients with RSEI (0.906) and the Mine-specific Eco-environment Index (MSEEI) (0.931). During the 2018 drought, MDECI maintained a robust ACC of 0.628 while RSEI dropped to 0.482. (3) Multi-scale analysis revealed a unimodal MDECI response with an ETP at −100 mm. Initial ‘micro-disturbance gain’ (0.371 to 0.471) is followed by a progressive decline to a minimum of 0.185 under severe deformation. (4) Local Indicators of Spatial Association (LISA) spatial clustering characterized the distribution patterns of ecological damage and localised high-maintenance areas. High–Low damaged areas accounted for 5.09%, while High–High high-maintenance areas reached 9.00%. The scale of High–High areas was approximately 1.77 times that of the damaged areas. The MDECI addresses the deficiencies of traditional indices in high-disturbance areas and isolates the impact of mining on the ecology, providing a quantitative basis for risk identification and differentiated restoration. Full article
(This article belongs to the Section Remote Sensing in Geology, Geomorphology and Hydrology)
Show Figures

Figure 1

20 pages, 837 KB  
Article
Perceived Conservation Effectiveness as a Driver of Cultural Ecosystem Service Value in a Transboundary River Corridor: Evidence from the Lower Jordan River Basin
by Ansam Bzour and István Valánszki
Land 2026, 15(5), 697; https://doi.org/10.3390/land15050697 - 22 Apr 2026
Abstract
River corridor rehabilitation is increasingly expected to deliver coupled outcomes by combining ecological recovery with measurable improvements in human well-being. Cultural ecosystem services (CESs), the non-material benefits people derive from landscapes, are central to this objective but remain difficult to operationalize in securitized [...] Read more.
River corridor rehabilitation is increasingly expected to deliver coupled outcomes by combining ecological recovery with measurable improvements in human well-being. Cultural ecosystem services (CESs), the non-material benefits people derive from landscapes, are central to this objective but remain difficult to operationalize in securitized transboundary settings, where border governance, uneven mobility, and community histories shape access to rivers and the formation of cultural meanings. This study examines whether perceived conservation effectiveness is associated with higher CES value in the Lower Jordan River Basin (LJRB) and whether this association persists after accounting for the community-group structure. Using survey data from 445 respondents across seven community groups, the perceived CES valuation was assessed through a five-point Cultural Significance rating, analyzed alongside conservation-related and contextual variables. Conservation was measured through perceived conservation impact and self-reported conservation involvement (yes/no). A staged inference design combined group comparisons and multivariable regression with adjustments for the community-group structure and contextual controls. Conservation involvement was not associated with meaningful differences in Cultural Significance. The perceived conservation impact showed a positive association in pooled and simple models but lost independent significance after adjusting for community-group structure, which accounted for much of the explanatory power. These findings indicate that CES valuation in the LJRB is structured more by community-group differences and borderland conditions than by individual conservation participation, underscoring the importance of locally encounterable outcomes and group-tailored engagement strategies in transboundary river planning. Full article
17 pages, 468 KB  
Article
Proximity-Based Digital Practices in Fashion—Ateliers of Social Integration as Relational Infrastructures of Care and Innovation
by Cecilia Manzo, Silvia Mazzucotelli Salice and Michele Varini
Societies 2026, 16(5), 135; https://doi.org/10.3390/soc16050135 - 22 Apr 2026
Abstract
This article advances a critical rethinking of digital transformation in craft-based and socially embedded production systems by examining ateliers of social integration as community-led solidarity spaces where sewing and embroidery practices intersect with relational, care-oriented, and collective dimensions. Existing debates on digitalisation [...] Read more.
This article advances a critical rethinking of digital transformation in craft-based and socially embedded production systems by examining ateliers of social integration as community-led solidarity spaces where sewing and embroidery practices intersect with relational, care-oriented, and collective dimensions. Existing debates on digitalisation remain largely centred on automation, scale, and efficiency, overlooking how technology operates within care-based and territorially embedded economies. To address this gap, the article develops an alternative analytical framework grounded in relational economies and the ethics of care. While the phenomenon is transnational, the empirical analysis focuses on the Italian context and draws on data from CreAbility, an ongoing action-research project aimed at building a digital community of micro and small fashion enterprises, associations, and designers characterized by social and cultural impact. Against dominant, scale-oriented models of innovation, the article conceptualises ateliers of social integration as relational ecosystems in which value is co-produced through social ties, inclusion practices, and localized knowledge. From this perspective, digital technologies serve as situated mediators that extend and amplify proximity-based relations. This reframing challenges linear and growth-centred accounts of digital innovation, instead proposing a non-linear, care-centred, and place-based model of digital transformation. Methodologically, the study adopts a mixed-methods design combining quantitative and qualitative techniques. Data were collected between June and July 2025 through an online questionnaire distributed to a broader population of Italian ateliers of social integration and were complemented by participatory focus groups involving organisational representatives. The findings show that these ateliers operate as infrastructures of proximity in which production, care, and community are co-constitutive, and where digital practices support forms of extended embeddedness rather than substitution. In doing so, the article contributes to debates on digitalisation, social innovation, and the care economy by showing how alternative, relational, and non-scalable models of production can reshape the meaning and the trajectories of innovation. Full article
24 pages, 2806 KB  
Article
Contactless Cardiac Health Monitoring with Millimeter-Wave Radar Based on PMG-SATNet
by Tianjiao Guo, Jianqi Wang, Nianzeng Yuan, Hao Lv, Fulai Liang, Zhiyuan Zhang, Jingzhe Wang, Yunuo Long and Huijun Xue
Sensors 2026, 26(9), 2579; https://doi.org/10.3390/s26092579 - 22 Apr 2026
Abstract
Cardiovascular diseases are the primary causes of mortality worldwide, often characterized by subtle onset and acute progression. Traditional ECG electrodes may cause skin irritation, limiting routine monitoring and early risk assessment. Relying on the advantages of non-contact monitoring, millimeter-wave radar-based cardiac monitoring combined [...] Read more.
Cardiovascular diseases are the primary causes of mortality worldwide, often characterized by subtle onset and acute progression. Traditional ECG electrodes may cause skin irritation, limiting routine monitoring and early risk assessment. Relying on the advantages of non-contact monitoring, millimeter-wave radar-based cardiac monitoring combined with deep learning has become a popular research direction recently. To overcome the poor generalization of methods trained from single-source datasets, this study designed seven experimental scenarios covering wakefulness and sleep. A novel deep learning network consisting of encoder and decoder structures named PMG-SATNet was proposed. The encoder comprises a parallel multi-scale feature extraction module and a global temporal relationship modeling module to capture fine-grained local patterns and long-range dependencies. The decoder employs a temporal convolutional network augmented with a spectral attention mechanism to emphasize clinically relevant ECG frequency bands and suppress respiration and body motion interference. After being validated on the self-built dataset, PMG-SATNet outperformed baseline models in terms of Pearson correlation coefficient and root mean square error, with an improvement of 3.3% and 3.8%, and 16.4% and 23.8%, respectively. The validation results imply that PMG-SATNet is capable of recovering ECG signals from millimeter-wave radar-derived chest vibrations with high fidelity and can potentially be implemented in real-life cardiac health monitoring. Full article
(This article belongs to the Special Issue Advanced Non-Invasive Sensors: Methods and Applications—2nd Edition)
Show Figures

Figure 1

26 pages, 13175 KB  
Article
QHAWAY: An Instance Segmentation and Monocular Distance Estimation ADAS for Vulnerable Road Users in Informal Andean Urban Corridors
by Abel De la Cruz-Moran, Hemerson Lizarbe-Alarcon, Wilmer Moncada, Victor Bellido-Aedo, Carlos Carrasco-Badajoz, Carolina Rayme-Chalco, Cristhian Aldana Yarlequé, Yesenia Saavedra, Edwin Saavedra and Alex Pereda
Sensors 2026, 26(8), 2569; https://doi.org/10.3390/s26082569 - 21 Apr 2026
Abstract
Vulnerable road users in informal urban environments confront a distinct set of hazards that standard computer vision datasets are ill-equipped to represent: artisanal speed bumps constructed without regulatory compliance, deteriorated road markings, and the mototaxi—a three-wheeled motorized vehicle that constitutes the primary informal [...] Read more.
Vulnerable road users in informal urban environments confront a distinct set of hazards that standard computer vision datasets are ill-equipped to represent: artisanal speed bumps constructed without regulatory compliance, deteriorated road markings, and the mototaxi—a three-wheeled motorized vehicle that constitutes the primary informal transport mode in intermediate Andean cities yet is absent from all major international repositories. This paper presents QHAWAY—from Quechua qhaway, a transitive verb meaning “to look; to observe”—an Advanced Driver Assistance System (ADAS) predicated on instance segmentation, monocular distance estimation via the pinhole camera model, and Time-to-Collision (TTC) computation, developed for the road environment of Ayacucho, Peru (2761 m a.s.l.), a city recognised by UNESCO as a Creative City of Crafts and Folk Art since 2019. A hybrid dataset comprising 25,602 images with 127,525 annotated instances across 12 classes was assembled by combining an original local collection of 4598 images (10,701 instances) captured through four complementary acquisition methods across the five urban districts of the Huamanga province with three established international datasets (BDD100K, BSTLD, RLMD; 21,004 images, 116,824 instances). A three-phase progressive training strategy with monotonically increasing resolution (640, 800, and 1024 pixels) was evaluated as an ablation study. A multi-architecture comparison spanning YOLOv8L-seg and the YOLO26 family (nano, small, large) identified YOLO26L-seg as the best-performing model, attaining mAP50 Box of 0.829 and mAP50 Mask of 0.788 at epoch 179. The integration of ByteTrack multi-object tracking with the pinhole equation D=(Hreal×f)/hpx delineates operational risk zones aligned with the NHTSA forward collision warning standard (danger: <3 m; caution: 3–7 m; TTC threshold ≤ 2.4 s). The system sustains processing rates of 19.2–25.4 FPS on an NVIDIA RTX 5080 GPU. A systematic field survey established that 96% of the audited speed bumps fail to comply with MTC Directive No. 01-2011-MTC/14, constituting the first quantitative record of informal road infrastructure non-compliance in the Andean region. Validation was conducted under naturalistic driving conditions without staged scenarios. Grad-CAM explainability analysis, encompassing three complementary visualisation algorithms (Grad-CAM, Grad-CAM++, and EigenCAM), confirmed that model attention concentrates consistently on safety-critical objects. Full article
28 pages, 1811 KB  
Article
A Weighted Mean of Vectors-Based Mathematical Optimization Framework for PV-STATCOM Deployment in Distribution Systems Under Time-Varying Load Conditions
by Ghareeb Moustafa, Hashim Alnami, Badr M. Al Faiya and Sultan Hassan Hakmi
Mathematics 2026, 14(8), 1351; https://doi.org/10.3390/math14081351 - 17 Apr 2026
Viewed by 108
Abstract
The increasing penetration of photovoltaic (PV) systems in distribution networks has introduced new challenges in voltage regulation and energy loss mitigation, particularly under time-varying loading conditions. This paper presents a constrained multi-objective mathematical optimization framework for the optimal allocation and sizing of PV-STATCOM [...] Read more.
The increasing penetration of photovoltaic (PV) systems in distribution networks has introduced new challenges in voltage regulation and energy loss mitigation, particularly under time-varying loading conditions. This paper presents a constrained multi-objective mathematical optimization framework for the optimal allocation and sizing of PV-STATCOM devices in radial distribution systems. The problem is formulated as a nonlinear optimization model that minimizes the daily energy losses over a 24 h operating horizon while satisfying network operational constraints, inverter capacity limits, and renewable penetration restrictions. To efficiently solve the resulting non-convex optimization problem, a metaheuristic algorithm based on the weighted mean of vectors (WMV) is employed. The WMV method integrates wavelet-based weighting mechanisms, mean-driven update rules, vector combination strategies, and a local refinement operator to balance global exploration and local exploitation within the feasible search domain. Constraint violations are handled through a penalty-based mathematical transformation of the objective function. The proposed framework is validated on the IEEE 33-bus and IEEE 69-bus distribution systems under realistic daily load variations. The numerical results demonstrate significant reductions in daily energy losses compared to differential evolution, particle swarm optimization, artificial rabbits optimization, and golden search optimization algorithms. Furthermore, convergence analysis confirms the robustness and computational efficiency of the WMV approach in solving large-scale constrained power system optimization problems. Full article
(This article belongs to the Special Issue Mathematical Methods Applied in Power Systems, 2nd Edition)
26 pages, 8932 KB  
Article
Differentiable Superpixel Generation with Complexity-Aware Initialization and Edge Reconstruction for SAR Imagery
by Hang Yu, Jiaye Liang, Gao Han and Lei Wang
Remote Sens. 2026, 18(8), 1213; https://doi.org/10.3390/rs18081213 - 17 Apr 2026
Viewed by 142
Abstract
Synthetic Aperture Radar (SAR) imagery is inherently degraded by multiplicative speckle noise, rendering traditional superpixel methods—which rely on hard assignment and uniform initialization—suboptimal for boundary preservation. This study proposes a complexity-aware superpixel generation framework featuring differentiable soft-assignment optimization. The approach employs an F-LGRP [...] Read more.
Synthetic Aperture Radar (SAR) imagery is inherently degraded by multiplicative speckle noise, rendering traditional superpixel methods—which rely on hard assignment and uniform initialization—suboptimal for boundary preservation. This study proposes a complexity-aware superpixel generation framework featuring differentiable soft-assignment optimization. The approach employs an F-LGRP (Fusion of Local Gradient Pattern Representation) feature descriptor that fuses regional gradient statistics via Gaussian filtering to suppress speckle, coupled with a complexity-driven recursive quadtree initialization strategy yielding non-uniform seed density. A U-Net architecture predicts soft pixel–superpixel association maps within a 9-neighborhood constraint, supervised by a multi-objective loss integrating edge information reconstruction and boundary feature reconstruction. Comprehensive evaluations on simulated and real SAR images (WHU-OPT-SAR and Munich) demonstrate that the proposed method achieves state-of-the-art performance across Boundary Recall, Undersegmentation Error, Compactness, and Achievable Segmentation Accuracy compared to SLIC, SNIC, Mean-Shift, PILS, and SSN. Validation on downstream segmentation tasks further confirms superior accuracy and computational efficiency, establishing the framework as an effective solution for end-to-end SAR image analysis. Full article
(This article belongs to the Section Remote Sensing Image Processing)
16 pages, 3388 KB  
Article
A Fast Calculation Method for Electrostatic Fields in Complex Terrain Using NSGA-II and Conformal Mapping
by Xiaojian Wang, Xinyu Shi, Tianlei He, Xiaobin Cao and Ruifang Li
Electronics 2026, 15(8), 1689; https://doi.org/10.3390/electronics15081689 - 17 Apr 2026
Viewed by 130
Abstract
Rapid and accurate calculation of lightning-induced electric fields in complex terrain is essential for lightning protection and electromagnetic compatibility analysis. Although conventional full-wave numerical methods such as the finite element method can achieve high-fidelity results, they are computationally expensive and inefficient for large-scale [...] Read more.
Rapid and accurate calculation of lightning-induced electric fields in complex terrain is essential for lightning protection and electromagnetic compatibility analysis. Although conventional full-wave numerical methods such as the finite element method can achieve high-fidelity results, they are computationally expensive and inefficient for large-scale or repetitive engineering analysis. To enable efficient and reliable computation of lightning-induced electrostatic fields over complex terrain, this paper proposes a fast computational framework that integrates multi-level conformal mapping with a multi-objective optimization strategy based on the Non-Dominated Sorting Genetic Algorithm II (NSGA-II). In the proposed method, irregular terrain boundaries are transformed into analytically tractable domains using multi-level conformal mapping, while the critical mapping parameter is reformulated as a dual-objective optimization problem that simultaneously minimizes the maximum local error and the mean global error. Unlike traditional approaches that rely on empirical tuning or exhaustive traversal of mapping parameters, the proposed framework establishes a closed-loop adaptive optimization process that generates a Pareto-optimal solution set, enabling flexible trade-off selection according to practical accuracy requirements. The method is validated against high-fidelity finite element simulations for representative terrain profiles. The results demonstrate that the proposed approach achieves comparable maximum-error performance while reducing mean error and significantly improving parameter-optimization efficiency relative to exhaustive search methods. The proposed framework provides an adaptive and efficient computational solution for preliminary assessment of lightning-induced electric fields in complex terrain environments, and lays a foundation for future extensions toward more realistic multi-dimensional and transient analyses. The improvements in computational accuracy and efficiency offer significant practical value for rapid lightning protection assessment in large-scale complex terrain engineering, enabling parametric analysis and scheme comparison during the preliminary engineering design stage with sufficient reliability. Full article
(This article belongs to the Section Artificial Intelligence)
Show Figures

Figure 1

31 pages, 1795 KB  
Article
An Analysis of the Impact of High-Quality Urban Development on Non-Point Source Pollution in the Chenghai Lake Drainage Basin Based on Multi-Source Big Data
by Mingbiao Chen and Xiong He
Land 2026, 15(4), 660; https://doi.org/10.3390/land15040660 - 16 Apr 2026
Viewed by 186
Abstract
With urbanization transforming from scale expansion to high-quality development and the increasing prominence of the ecological environment constraints of drainage basins, systematically identifying the mechanism of action of non-point source pollution from a high-quality development perspective is significant for coordinating urban development and [...] Read more.
With urbanization transforming from scale expansion to high-quality development and the increasing prominence of the ecological environment constraints of drainage basins, systematically identifying the mechanism of action of non-point source pollution from a high-quality development perspective is significant for coordinating urban development and environmental protection. Based on remote sensing data on atmospheric pollution and multi-source spatial big data such as nighttime light (NTL), LandScan population, point of interest (POI), and land use data from 2013 to 2025, this study applies methods including deposition flux analysis, deep learning fusion, bivariate spatial autocorrelation, and geographically weighted regression (GWR) to empirically analyze the spatiotemporal evolution characteristics, spatial correlation, and local impacts of high-quality urban development on non-point source pollution in the Chenghai drainage basin. We find that, firstly, non-point source pollution and high-quality urban development in the Chenghai drainage basin both present significant stage-specific and spatial heterogeneity. In other words, the two are not mutually independent spatial elements in space; instead, they are closely and significantly correlated, with their correlation types showing obvious spatial agglomeration characteristics. Secondly, the impact of high-quality urban development on non-point source pollution evolves in stages. It gradually shifts from a whole-region, homogeneous, strongly positive driving force to spatial differentiation. Specifically, from 2013 to 2017, the whole-region regression coefficients are generally greater than 0.5, meaning that urban development represents a strong, whole-region driving force promoting pollution. However, after 2017, this impact evolves into a stable spatial differentiation pattern. It mainly shows that the northern urban core area, where coefficients are greater than 0.5, maintains a continuous strong positive driving force. Meanwhile, the peripheral area, where coefficients are generally lower than 0, creates a negative inhibition effect. Based on the above rules, further analysis shows that the impact of high-quality urban development on non-point source pollution is absolutely not a simple linear relationship. Instead, it is a result of the coupling effect of multiple factors, including development stage, spatial location, and governance level. Therefore, to positively affect the ecological environment through high-quality development, model transformation and precise governance are essential. The findings of this study deepen our understanding of the transformation of urban development models and the response mechanism of non-point source pollution. They also provide a scientific basis and decision support for promoting the coordinated governance of high-quality urban development and non-point source pollution by region and stage in plateau lake drainage basins, as well as for improving the sustainable development of drainage basins. Full article
31 pages, 2771 KB  
Article
Asymptotic Solutions for Atmospheric Internal Gravity Waves Generated by a Thermal Forcing in an Anelastic Fluid Flow with Vertical Shear
by Amna M. Grgar and Lucy J. Campbell
AppliedMath 2026, 6(4), 63; https://doi.org/10.3390/appliedmath6040063 - 16 Apr 2026
Viewed by 114
Abstract
Asymptotic solutions are derived to model the development of atmospheric internal gravity waves generated by latent heating in a two-dimensional configuration involving a vertically-sheared background flow. The mathematical model comprises nonlinear partial differential equations derived from the conservation laws of fluid dynamics under [...] Read more.
Asymptotic solutions are derived to model the development of atmospheric internal gravity waves generated by latent heating in a two-dimensional configuration involving a vertically-sheared background flow. The mathematical model comprises nonlinear partial differential equations derived from the conservation laws of fluid dynamics under the anelastic approximation where the background density and temperature vary with altitude. The latent heating is represented by a horizontally-periodic but vertically-localized nonhomogeneous forcing term in the energy conservation equation. This generates gravity waves that are considered as perturbations to the background flow and are expressed as perturbation series, with the leading-order contributions being the solutions of linearized equations. Taking into account the nonlinear terms at the next order gives expressions for the effects of the waves on the background mean flow. Due to the vertical shear, there is a critical level where momentum and energy are transferred from the wave modes to the mean flow. The asymptotic solutions show that the wave–mean-flow interaction is nonlocal and occurs over the range of altitudes from the thermal forcing level up the critical level. This is in contrast to what occurs in the case of waves forced by an oscillatory lower boundary, where the interaction is typically localized around the critical level. It is found that the wave drag is negative above the thermal forcing level, making the mean flow velocity more negative, but it becomes positive as the waves approach the critical level, indicating wave absorption in this region. There is wave transmission through the critical level, as well as absorption, and the extent of transmission depends on the depth of the latent heating profile. The mean potential temperature is reduced above the thermal forcing level and enhanced at the critical level, a situation that could ultimately lead to the development of convective instabilities. Full article
Show Figures

Figure 1

18 pages, 17468 KB  
Article
One-Way Ranging for LoRa: A Chirp-Based Estimation Approach
by Luz E. Marquez, Maria Calle and John E. Candelo-Becerra
Future Internet 2026, 18(4), 207; https://doi.org/10.3390/fi18040207 - 15 Apr 2026
Viewed by 291
Abstract
Many Internet of Things (IoT) applications that use LoRaWAN require node localization, often relying on signal strength or message timestamps to estimate distance. However, traditional techniques typically require prior knowledge of signal propagation models or clock synchronization between multiple nodes. Therefore, this paper [...] Read more.
Many Internet of Things (IoT) applications that use LoRaWAN require node localization, often relying on signal strength or message timestamps to estimate distance. However, traditional techniques typically require prior knowledge of signal propagation models or clock synchronization between multiple nodes. Therefore, this paper proposes a one-way ranging method based on LoRa to estimate link distances using the received signal from a single node, with no additional infrastructure or synchronization requirements. The approach uses the inherent properties of the LoRa chirp-based waveform to extract time delay information and estimate distance. The proposed method consists of a transmitter and a receiver capable of detecting the link delay using demodulation of the preamble. Then, the method estimates the distance using the link delay without requiring additional hardware or information. The method was validated through MATLAB R2025a simulations, including five nodes distributed over an 18 km2 area. The proposed method achieves distance estimation with mean errors of 25 m under semi-urban, non-line-of-sight conditions, outperforming existing methods. Additionally, the study identifies two practical system configurations for LoRa, at 8 Msps and 2 Msps, which reduce the ranging error while considering hardware feasibility. These findings are especially relevant for researchers developing Global Positioning System (GPS) free localization techniques in resource-constrained IoT environments. Full article
(This article belongs to the Special Issue Intelligent Telecommunications Mobile Networks)
Show Figures

Graphical abstract

28 pages, 5694 KB  
Article
A Chaotic Signal Denoising Method Based on Feature Mode Decomposition and Amplitude-Aware Permutation Entropy
by Zixiao Huang and Liang Xie
Symmetry 2026, 18(4), 651; https://doi.org/10.3390/sym18040651 - 13 Apr 2026
Viewed by 195
Abstract
Chaotic signals commonly exhibit nonlinear and nonstationary characteristics, while noise contamination reduces signal interpretability and degrades subsequent feature extraction and dynamical analysis. To improve the stability of mode-boundary determination and mitigate reconstruction distortion, this paper proposes a hybrid denoising framework that integrates feature [...] Read more.
Chaotic signals commonly exhibit nonlinear and nonstationary characteristics, while noise contamination reduces signal interpretability and degrades subsequent feature extraction and dynamical analysis. To improve the stability of mode-boundary determination and mitigate reconstruction distortion, this paper proposes a hybrid denoising framework that integrates feature mode decomposition (FMD), amplitude-aware permutation entropy (AAPE), dual-tree complex wavelet transform (DTCWT), and Savitzky–Golay (SG) filtering. First, the noisy signal is decomposed into multiple mode components using FMD. Then, the AAPE of each mode is calculated to adaptively distinguish high-frequency noise-dominant modes from non-high-frequency modes. For the high-frequency noise-dominant modes, improved logarithmic threshold shrinkage is applied to the magnitudes of DTCWT complex coefficients to suppress random noise and reduce threshold-induced bias. For the non-high-frequency modes, SG filtering is employed to further attenuate residual noise while preserving local waveform structures. Finally, the processed modes are reconstructed to obtain the denoised signal. Experiments on a simulated Lorenz chaotic signal and a real-world sunspot time series demonstrate that, across different noise levels, AAPE provides more stable mode partitioning than ApEn, CC, and CMSE. Moreover, under Gaussian white noise, Poisson noise, and uniform noise, the proposed method generally achieves a higher output signal-to-noise ratio (SNR) and a lower root mean square error (RMSE) than WT, CEEMD, EEMD, CEEMDAN+LMS, and VMD, while also yielding better performance in phase-space reconstruction and temporal-detail recovery. These results verify the effectiveness and practical applicability of the proposed method for chaotic signal denoising. Full article
(This article belongs to the Section Mathematics)
Show Figures

Figure 1

20 pages, 3345 KB  
Article
The Geography of Water Pipe Use: A Case Study in Tabriz City, Northwestern Iran
by Alireza Mohammadi, Arshad Ahmed, Elahe Pishgar, Munazza Fatima and Robert Bergquist
ISPRS Int. J. Geo-Inf. 2026, 15(4), 169; https://doi.org/10.3390/ijgi15040169 - 13 Apr 2026
Viewed by 316
Abstract
Water pipe smoking, or hookah smoking, is a growing public health concern ingrained in urban leisure cultures. Even though hookah smoking is common, the localized spatial drivers of this activity are still poorly understood. In order to close this gap, this study examined [...] Read more.
Water pipe smoking, or hookah smoking, is a growing public health concern ingrained in urban leisure cultures. Even though hookah smoking is common, the localized spatial drivers of this activity are still poorly understood. In order to close this gap, this study examined the locations of 273 hookah cafés in the Tabriz metropolis in Iran, modeling the distribution of these cafés against eight urban predictors: population density, road networks, and six distinct land use categories, such as commercial, administrative, educational, industrial, religious, and recreational land use. We combined Kernel Density Estimation (KDE) with Local Bivariate Relationships (LBR) using a high-resolution spatial approach. The findings indicate a non-random and spatially clustered pattern, using entropy-based measures of local relationship complexity. With the highest mean entropy value (0.84) and percentage of significant relationships (87.7%), educational land use density was found to be the best predictor. Additionally, there was a robust and consistent correlation with commercial land use density. Relationships with administrative and recreational land uses, on the other hand, showed lower entropy and were weaker and more dispersed. According to this study’s findings, the distribution of hookah cafés is spatially correlated to youth concentration and commercial activity patterns. Entropy analysis reveals substantial neighborhood-level variation in predictor influence, highlighting the value of local spatial analysis for identifying place-specific exposure. Full article
Show Figures

Figure 1

Back to TopTop