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
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
remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (10,986)

Search Parameters:
Keywords = cluster system

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
16 pages, 1757 KB  
Article
Dengue Epidemiology in Mexico: Temperature as a Contributing Factor to National Dengue Trends
by Juan Manuel Bello-López, Dulce Milagros Razo Blanco-Hernández, Andres Emmanuel Nolasco-Rojas, Emilio Mariano Durán-Manuel, Víctor Hugo Gutiérrez-Muñoz, Carol Vivian Moncayo-Coello, Jesus Alberto Meléndez-Ordoñez, José Alberto Díaz-Quiñonez, Magnolia del Carmen Ramírez-Hernández, Adolfo López-Ornelas, María Concepción Tamayo-Ordóñez, Yahaira de Jesús Tamayo-Ordóñez, Francisco Alberto Tamayo-Ordóñez, Benito Hernández-Castellanos, Luis Gustavo Zárate-Sánchez, Oscar Sosa-Hernández, Julio César Castañeda-Ortega, Claudia Camelia Calzada-Mendoza, Alejandro Cárdenas-Cantero, Clemente Cruz-Cruz and Miguel Ángel Loyola-Cruzadd Show full author list remove Hide full author list
Diseases 2026, 14(4), 133; https://doi.org/10.3390/diseases14040133 - 7 Apr 2026
Abstract
The increasing burden of dengue represents a growing global public health concern. Among the factors associated with rising dengue incidence, climate change, particularly increasing temperatures, has been frequently highlighted, alongside other environmental, biological, and social determinants. The emergence of dengue in previously non-endemic [...] Read more.
The increasing burden of dengue represents a growing global public health concern. Among the factors associated with rising dengue incidence, climate change, particularly increasing temperatures, has been frequently highlighted, alongside other environmental, biological, and social determinants. The emergence of dengue in previously non-endemic areas and its sustained increase in incidence have become increasingly common in recent decades. Objective: The aim of this study was to describe national dengue case trends in Mexico from 1990 to 2023 and to assess their association with temperature over the same period using a descriptive, retrospective analysis of epidemiological surveillance and temperature data. Methods: Epidemiological data on confirmed dengue cases and incidence were obtained from the Morbidity Yearbook of the General Directorate of Epidemiology (DGE) of the Mexican Ministry of Health. These data were used to construct epidemic curves and to analyze the geographic distribution of incidence using quartiles. Temperature data were derived from the national annual mean calculated from monthly reports issued by the National Water Commission (CONAGUA). Associations between temperature and dengue cases and incidence were explored over the study period. Results: Temporal analysis revealed a significant increase in both dengue cases and incidence in Mexico, with a positive association with temperature during the same period. Quartile-based geographic analysis showed that state-level classifications remained relatively stable across periods, with several states clustering within or tending toward the group considered endemic. Conclusions: The results of this study show an increase in cases and incidence of dengue over time, as well as a positive association between cases/incidence of dengue in Mexico and the increase in the national average temperature during the study period; however, due to its descriptive and retrospective design, causal inference is not possible. Dengue transmission is inherently multifactorial, and the observed trends likely reflect the combined influence of climatic conditions, historical expansion of transmission cycles, vector establishment, and unmeasured socio-epidemiological factors. The absence of entomological indicators, additional climatic variables, and spatially or seasonally disaggregated analyses limits the ability to capture localized dynamics. Overall, temperature should be interpreted as a contributing factor within a complex system rather than as the sole driver of dengue trends, underscoring the need for integrated surveillance and control strategies in both endemic and non-endemic regions. Full article
(This article belongs to the Section Infectious Disease)
Show Figures

Figure 1

22 pages, 2283 KB  
Article
Urban Style and Features’ Visual Quality and Influencing Factors: A Case Study of Fangcheng Historical and Cultural District in Shenyang, China
by Ning Tang, Sa Wang and Mei Lyu
Buildings 2026, 16(7), 1455; https://doi.org/10.3390/buildings16071455 - 7 Apr 2026
Abstract
Historical and cultural districts are the outcome of cultural sedimentation brought about by urban development, and they embody distinctive urban historical and cultural connotations. Ignoring the protection of the historical and cultural value contained in streetscapes will not only decrease the life quality [...] Read more.
Historical and cultural districts are the outcome of cultural sedimentation brought about by urban development, and they embody distinctive urban historical and cultural connotations. Ignoring the protection of the historical and cultural value contained in streetscapes will not only decrease the life quality of residents but will also diminish distinctive local urban features. This study focused on the Fangcheng historical and cultural district in Shenyang. The scenic beauty estimation method was employed to evaluate urban style and features’ visual quality, while the semantic differential method was used to obtain the subjective perceptual features of samples. The study also systematically explored the dynamic relationship between urban style and features’ quality and subjective perception in historical and cultural districts. The results show that color richness, coherence, iconic status, and continuum all exert significant positive predictive effects on visual preferences regarding urban style and features. Color richness was the primary determinant of urban style and features’ visual quality. Continuum interfaces, a unified spatial texture, and coordinated dimensions contributed significantly to improving urban style and features’ visual quality in historic and cultural districts. The distinctiveness and cultural iconic status of historical and cultural districts enhanced the residents’ identity and place memory. Moreover, the coherence and continuum of style between the old and new elements promoted an integrated aesthetic experience. The evaluation results revealed that the overall visual quality of urban style and features of most streets was medium. However, streets with a higher visual quality cluster among historical streets and commercial streets. The residential streets demonstrated a significantly lower visual quality. Establishing a comprehensive evaluation system that integrates urban style and features, subjective perception, and the style of historical and cultural districts can contribute to covering the shortage in the traditional urban style and features’ research and also provide a basis for urban regeneration at the micro scale. Full article
(This article belongs to the Section Architectural Design, Urban Science, and Real Estate)
Show Figures

Figure 1

20 pages, 4589 KB  
Article
Autoencoder-Based Latent Representation Learning, SoH Estimation, and Anomaly Detection in Electric Vehicle Battery Energy Storage Systems
by Nagendra Kumar, Anubhav Agrawal, Rajeev Kumar and Manoj Badoni
Vehicles 2026, 8(4), 81; https://doi.org/10.3390/vehicles8040081 - 7 Apr 2026
Abstract
Accurate estimation of battery state of health (SoH) is an important aspect for improving the reliability, safety, and operating efficiency of an energy storage system. This study presents a unified deep learning pipeline for prediction, latent feature extraction, and anomaly detection. A convolution [...] Read more.
Accurate estimation of battery state of health (SoH) is an important aspect for improving the reliability, safety, and operating efficiency of an energy storage system. This study presents a unified deep learning pipeline for prediction, latent feature extraction, and anomaly detection. A convolution neutral network autoencoder is used to learn compact latent features from a dataset (NASA battery datasets, i.e., B0005, B0006, B0007, and B0018). These features serve as inputs to random forest and linear regression models, which are further compared with the CNN and GRU. The system is evaluated using leave-one-group-out cross-validation to ensure robustness across different batteries. Latent space quality is studied using PSA, t-SNE, and UMAP analyses. Furthermore, clustering performance is measured using the Silhouette Score, and anomalies are detected using reconstruction error and the Isolation Forest technique. The obtained results show that the AE+RF model achieves the best performance, with a 0.0285 root mean square value (RMSE) and a 0.0109 mean absolute error (MAE), with a high 0.96 coefficient of determination (R2). It is evident that AE+RF shows high prediction accuracy and model reliability. The results show that latent features improve prediction accuracy, helping to clearly separate normal and abnormal patterns, providing a robust and accurate approach to battery SoH estimation that is suitable for battery management system applications. Full article
Show Figures

Graphical abstract

20 pages, 4400 KB  
Article
Tightly Coupled GNSS/IMU Hybrid Navigation Using Factor Graph Optimization with NLOS Detection Capability
by Haruki Tanimura and Toshiaki Tsujii
Sensors 2026, 26(7), 2264; https://doi.org/10.3390/s26072264 - 6 Apr 2026
Abstract
High-precision and reliable self-localization is essential for autonomous navigation systems. However, in urban canyons (urban environments with clusters of high-rise buildings), Global Navigation Satellite Systems (GNSS) suffer from severe multipath and Non-Line-of-Sight (NLOS) signal reception. This causes a theoretically unbounded positive bias in [...] Read more.
High-precision and reliable self-localization is essential for autonomous navigation systems. However, in urban canyons (urban environments with clusters of high-rise buildings), Global Navigation Satellite Systems (GNSS) suffer from severe multipath and Non-Line-of-Sight (NLOS) signal reception. This causes a theoretically unbounded positive bias in pseudorange measurements, significantly degrading positioning integrity. To address this challenge, this study proposes a novel GNSS/Inertial Measurement Unit (IMU) tightly coupled integrated navigation system using factor graph optimization (FGO) integrated with machine learning-based NLOS detection. To train the NLOS detection model, we utilized a dual-polarized antenna to label signals based on the strength difference between RHCP and LHCP components, achieving a detection accuracy of 0.89. A random forest classifier identifies NLOS signals, and based on its classification labels, the variance of the corresponding GNSS pseudorange factors within the FGO framework is dynamically inflated. This effectively mitigates the impact of outliers while preserving the graph topology. Experimental evaluations in dense urban environments demonstrated that the proposed method improves horizontal positioning accuracy by 84.8% compared to conventional standalone GNSS positioning. The dynamic integration of machine learning-based signal classification and tightly coupled FGO provides an extremely robust positioning solution, proven to meet the stringent reliability requirements demanded of autonomous systems even under severe signal obscuration. Full article
(This article belongs to the Special Issue Advances in GNSS/INS Integration for Navigation and Positioning)
Show Figures

Figure 1

15 pages, 349 KB  
Article
Ensemble-Based Short-Window Non-Linear Dynamical Characterization of PLC Impulsive Noise
by Steven O. Awino and Bakhe Nleya
Appl. Sci. 2026, 16(7), 3573; https://doi.org/10.3390/app16073573 - 6 Apr 2026
Abstract
Impulsive noise significantly degrades the performance of power line communication (PLC) systems due to their non-Gaussian amplitude distribution, burst clustering, and inherent temporal dependence. Conventional statistical and spectral models often describe marginal behavior but do not fully account for the underlying temporal organization [...] Read more.
Impulsive noise significantly degrades the performance of power line communication (PLC) systems due to their non-Gaussian amplitude distribution, burst clustering, and inherent temporal dependence. Conventional statistical and spectral models often describe marginal behavior but do not fully account for the underlying temporal organization of such noise processes. This paper introduces an ensemble-based non-linear dynamical framework for the short-window characterization of impulsive PLC noise using delay-embedded phase-space reconstruction (PSR). Rather than relying on extended stationary recordings, the analysis is conducted across multiple independent short-duration acquisition windows obtained from indoor low-voltage networks. For each realization, the delay parameter is selected using average mutual information, and the embedding dimension is determined through the false nearest neighbors (FNN) criterion. The reconstructed trajectories are then examined using correlation dimension estimation, largest Lyapunov exponent analysis, and recurrence quantification measures. The resulting non-linear descriptors reveal structured phase-space organization and low-dimensional dynamical characteristics that are not readily observable in the original time-domain representation. In addition, these findings show that short-window PLC data preserve meaningful dynamical characteristics and support the use of non-linear geometric descriptors for impulsive PLC noise analysis and future mitigation approaches. Full article
(This article belongs to the Special Issue Design, Optimization and Control Strategy of Smart Grids)
Show Figures

Figure 1

20 pages, 1183 KB  
Article
Empowering Urban Women Street Vendors Through the Impact of Digital Payments: An Empirical Investigation in the Megacity of Delhi
by Gayatri Mallick, Sonia Singla, Suraj Kumar Mallick, Netrananda Sahu, Martand Mani Mishra and Ayush Varun
Economies 2026, 14(4), 119; https://doi.org/10.3390/economies14040119 - 6 Apr 2026
Viewed by 46
Abstract
This article investigates whether increasing economic status through adopting digital payment capabilities in Delhi fosters economic and financial inclusion among urban women street vendors in Mahila Haat. Digital freedom is a new step forward in technology for everyone. Still, a woman not only [...] Read more.
This article investigates whether increasing economic status through adopting digital payment capabilities in Delhi fosters economic and financial inclusion among urban women street vendors in Mahila Haat. Digital freedom is a new step forward in technology for everyone. Still, a woman not only balances the social responsibilities of childbearing, caring for her children and family, and struggling with economic issues, health issues, and undernourishment, but can also balance the household job of street vending to increase self-esteem and financial independence. This research work conducted a sampling survey and applied the Kruskal–Wallis H-test with a p-value (0.05) significance level by evaluating 11 variables to investigate the relationship between the digital capabilities and economic independence of street vendors in Mahila Haat (a women’s market where the vendors are all women) in the Red Fort area of New Delhi. UPI systems were created using measurements based on a five-point Likert scale to analyze different levels of satisfaction in clusters of digital capabilities on digital platforms. Further, the ordinary least squares (OLS) method was used to estimate quality of life and social happiness in the context of digital empowerment. Digital payment systems positively influence women’s empowerment. Women vendors can adopt digital payment methods, making them economically independent. The positive relationship between women vendors and customer satisfaction before UPI use and after UPI use is also analyzed. This research will be helpful for both government and non-government organizations to provide financial assistance, informational awareness, skill development training, and advocacy for gender equality to increase women’s empowerment. Full article
Show Figures

Figure 1

37 pages, 7652 KB  
Article
Narrowing the Gap: Spatiotemporal Evolution, Convergence, and Policy Implications of China’s Green Inclusive Growth
by Feng Xiao and Fan Zhang
Sustainability 2026, 18(7), 3566; https://doi.org/10.3390/su18073566 - 6 Apr 2026
Viewed by 152
Abstract
Green inclusive growth is a crucial strategic choice for achieving high-quality development in China. This study constructs an indicator system encompassing economic, social, and ecological dimensions to quantitatively measure the level of green inclusive growth across 31 provinces (cities, autonomous regions) in China [...] Read more.
Green inclusive growth is a crucial strategic choice for achieving high-quality development in China. This study constructs an indicator system encompassing economic, social, and ecological dimensions to quantitatively measure the level of green inclusive growth across 31 provinces (cities, autonomous regions) in China from 2001 to 2021. The regional disparities, spatiotemporal evolution trends, and convergence characteristics are analyzed using the Dagum Gini coefficient, kernel density function, and σ-convergence and conditional β-convergence. The findings indicate the following: (1) China’s green inclusive growth generally exhibits a “high in the east, low in the west” spatial distribution pattern, with western regions demonstrating a catching-up trend. (2) The regional disparities in China’s green inclusive growth levels are showing a trend of gradual narrowing, though imbalances within eastern and western regions remain relatively pronounced. (3) The kernel density curve of China’s green inclusive growth maintains a “unimodal” shape, with no significant polarization or multi-polar differentiation. (4) Both the national level and the four major regional clusters exhibit σ-convergence and conditional β-convergence in green inclusive growth, demonstrating the effectiveness of policies aimed at reducing regional disparities. (5) Social capital, human capital, technological innovation, material capital investment, foreign direct investment, urbanization level, and government fiscal expenditure all have a positive promoting effect on China’s green and inclusive growth. These results provide decision-making references for promoting coordinated regional development and guiding the inclusive and green transformation of China’s economic growth. Full article
Show Figures

Figure 1

26 pages, 1230 KB  
Article
Tracking the Trends and Projection of Pediatric Malnutrition Towards Global Nutrition Targets by 2030—A Secondary Data Analysis of Low Middle-Income Countries
by Asif Khaliq, Bushra Ashar, Amreen, Safi Ullah Khan, Muhammad Junaid, Angus Ruggieri-Guthrie, Mohammad Javad Davoudabadi, Shafaq Taseen, Maryam Ranta, Mezhgan Kiwan, Nazeer Ahmed and Haji Abdul Rehman Akhter
Nutrients 2026, 18(7), 1160; https://doi.org/10.3390/nu18071160 - 4 Apr 2026
Viewed by 356
Abstract
Objective: This study aimed to estimate the trends, projections, and determinants of standalone and coexisting forms of malnutrition (CFM) at the global, regional, national, and individual level among children under five in low- and middle-income countries (LMICs). It also assessed the projection trajectory [...] Read more.
Objective: This study aimed to estimate the trends, projections, and determinants of standalone and coexisting forms of malnutrition (CFM) at the global, regional, national, and individual level among children under five in low- and middle-income countries (LMICs). It also assessed the projection trajectory towards the 2030 global nutrition targets (GNTs) for child growth including stunting, wasting, obesity, and CFM. Methods: Data from 48 LMICs were analyzed using the Multiple Indicator Cluster Surveys (MICS) and Demographic and Health Surveys (DHS). Children with complete anthropometry were included for national- and individual-level descriptive analyses. Projected prevalence of each form of malnutrition, including CFM, was calculated using the Annual Rate of Change. Inferential analyses employed generalized linear regression models with two-way interaction terms to identify determinants of each malnutrition type. Findings: By 2030, 22 of 48 LMICs are projected to achieve the GNT of stunting, wasting, and obesity, that is up from 10 countries currently, while Yemen and Zimbabwe are expected to remain off-track. Stunting is the most prevalent form, affecting 42 countries, with nine nations projected to have over 50% of children affected by a form of malnutrition. Wasting, obesity, and CFM are rising in several countries. Maternal education and household wealth were the strongest determinants, with children of uneducated mothers and from poorest households at the highest risk. Inequalities are narrowing slowly by 1–2% per year, and marked regional disparities persist. Conclusions: Many LMICs are off-track to meet child-growth targets when CFM is considered alongside standalone indicators. The government and global health partners must strengthen nutrition surveillance systems and equity-focused policies and programs to routinely capture CFM and prevent as well as manage all forms of malnutrition at the national and individual levels. Full article
(This article belongs to the Section Pediatric Nutrition)
Show Figures

Graphical abstract

16 pages, 2731 KB  
Article
Geometric Structure Prediction and NH3 Adsorption on Iridium Clusters
by Xianhui Gong, Yongli Liu, Bin Shen, Ruguo Dong, Yingwei Liu, Jiaqi Yuan and Yue Lu
Crystals 2026, 16(4), 243; https://doi.org/10.3390/cryst16040243 - 4 Apr 2026
Viewed by 129
Abstract
To investigate the structural characteristics of Irn clusters (n = 9–30) and their interaction with NH3, the CALYPSO structure-prediction method was employed to identify the lowest-energy configurations. The Lennard–Jones potential was then used to compute the binding energy and [...] Read more.
To investigate the structural characteristics of Irn clusters (n = 9–30) and their interaction with NH3, the CALYPSO structure-prediction method was employed to identify the lowest-energy configurations. The Lennard–Jones potential was then used to compute the binding energy and average binding energy, thereby evaluating size-dependent stability. The results show that Irn clusters evolve from relatively open motifs to compact three-dimensional frameworks as n increases. Meanwhile, the average binding energy increases overall and exhibits several locally stable size regions, indicating a pronounced size effect. Based on slab and cluster models, NH3 adsorption was further examined on the Ir13 cluster as a representative system due to its high structural stability as a “magic-number” cluster. The calculated adsorption energies demonstrate that the Ir13 cluster exhibits substantially stronger adsorption than the bulk Ir surface, with low-coordinated Ir atoms playing a key role in strengthening the interaction and enhancing adsorption activity. Adsorption-configuration analysis indicates that NH3 preferentially binds to active surface sites via the N lone pair. These findings clarify the relationship between structural stability and adsorption performance of Ir clusters and provide theoretical support for Ir-based materials in NH3 catalytic conversion and high-sensitivity gas detection, and offer insights relevant to improving NH3 monitoring in underground coal mine environments. Full article
(This article belongs to the Section Inorganic Crystalline Materials)
Show Figures

Figure 1

22 pages, 2152 KB  
Article
HCEA: A Multi-Agent Framework for Sustainable Human-Centered Entrepreneurship Based on a Large Language Model
by Yu Gao, Yanji Piao and Dongzhe Xuan
Sustainability 2026, 18(7), 3554; https://doi.org/10.3390/su18073554 - 4 Apr 2026
Viewed by 244
Abstract
Human-centered entrepreneurship considers employee well-being and uses the Sustainable Development Goals as its fundamental pillars. However, existing research predominantly focuses on institutional interventions and fails to provide integrated intelligent solutions for tackling human–machine collaboration issues in the context of digital transformation. Large language [...] Read more.
Human-centered entrepreneurship considers employee well-being and uses the Sustainable Development Goals as its fundamental pillars. However, existing research predominantly focuses on institutional interventions and fails to provide integrated intelligent solutions for tackling human–machine collaboration issues in the context of digital transformation. Large language models (LLMs) offer potential for affective computing and personalized support, but face critical gaps in ethical governance, privacy protection, and real-time risk intervention in sensitive entrepreneurial contexts. Our proposed Human-Centered Entrepreneurial Intelligent Agent (HCEA) framework achieves the unified optimization of task utility, empathetic expression, and ethical security by integrating a large language model core fine-tuned via a multi-objective hybrid loss function and a cluster of task-specialized intelligent agents. HCEA integrates retrieval-enhanced generation to ensure suggestion accuracy, a hierarchical data governance system for sensitivity-based privacy protection, and an independent risk detection module for real-time intervention and referral. We build the framework by constructing a hybrid entrepreneurial dataset, design the multi-agent architecture of decision support, emotion understanding and ethical risk tracking, and empirically evaluate both comparisons and ablation experiments. The results demonstrate that HCEA outperforms five baseline models across six key metrics, including entrepreneurship guidance relevance, emotion recognition, and high-risk recall. This study contributes to the intersection of digital transformation and sustainable entrepreneurship by providing a technically feasible, ethically grounded intelligent framework that empowers enterprises to reconcile efficiency with human-centric values, advancing SDG 8 (decent work and economic growth) and SDG 9 (industry, innovation, and infrastructure). Full article
Show Figures

Figure 1

27 pages, 8355 KB  
Article
Calibration of Roughness of Standard Samples Using Point Cloud Based on Line Chromatic Confocal Method
by Haotian Guo, Ting Chen, Xinke Xu, Yuexin Qiu, Jian Wu, Lei Wang, Huaichu Ye, Xuwen Chen and Ning Chen
Electronics 2026, 15(7), 1517; https://doi.org/10.3390/electronics15071517 - 4 Apr 2026
Viewed by 191
Abstract
This article proposes a calibration method combining line chromatic confocal and 3D point cloud processing to solve surface damage and low efficiency in traditional roughness sample calibration. Line chromatic confocal sensors scan roughness samples to obtain dense point clouds. We propose a back [...] Read more.
This article proposes a calibration method combining line chromatic confocal and 3D point cloud processing to solve surface damage and low efficiency in traditional roughness sample calibration. Line chromatic confocal sensors scan roughness samples to obtain dense point clouds. We propose a back projection mechanism, the adaptive density-based spatial clustering of applications with noise statistical outlier removal (BPM-ADBSCAN-SOR) algorithm that utilizes the ADBSCAN and SOR algorithms to address outlier noise and near-field noise in low-resolution point clouds, respectively, and then employs bounding boxes to crop the original high-resolution point cloud, thereby achieving multi-scale noise removal and point cloud clustering. We propose a Steady-State Confidence-Weighted Robust Gaussian Filtering (SSCW-RGF) algorithm, which calculates the range of the steady-state region, designs a steady-state region credibility weighting function to apply a weighted correction to the baseline fitting results, and then incorporates M-estimation theory to develop a robust Gaussian filtering algorithm weighted by steady-state region credibility, thereby mitigating the impact of outliers on Gaussian baseline fitting. Experiments verify the system accuracy: repeatability standard deviation is 0.0355 μm, relative repeatability error 0.3984%. Compared with reference block nominal values, the maximum absolute error is −0.745 μm, meeting specification tolerance. Compared with the contact profilometer, the maximum absolute error is 0.050 μm, the maximum relative error is +4.5%, and the calibration efficiency is improved by 90%. It provides a new approach for surface roughness calibration Full article
Show Figures

Figure 1

29 pages, 1107 KB  
Article
Secure Uplink Transmission in UAV-Assisted Dual-Orbit SAGIN over Mixed RF-FSO Links
by Zhan Xu and Chunshuai Ma
Aerospace 2026, 13(4), 341; https://doi.org/10.3390/aerospace13040341 - 4 Apr 2026
Viewed by 126
Abstract
To meet the need for global coverage, space–air–ground integrated networks (SAGINs) are crucial, but the openness of wireless links makes communications vulnerable to eavesdropping. This paper investigates the physical layer security (PLS) of uplink transmissions in a cooperative dual-hop SAGIN. The system comprises [...] Read more.
To meet the need for global coverage, space–air–ground integrated networks (SAGINs) are crucial, but the openness of wireless links makes communications vulnerable to eavesdropping. This paper investigates the physical layer security (PLS) of uplink transmissions in a cooperative dual-hop SAGIN. The system comprises a ground source with a directional antenna, an unmanned aerial vehicle (UAV) relay cluster, and a low Earth orbit (LEO) satellite. Utilizing stochastic geometry, we model the spatial randomness of terrestrial eavesdroppers and the multi-layered dual-orbital LEO destination. To combat mixed radio-frequency (RF) and free-space optical (FSO) fading, multiple relay selection and maximum ratio combining (MRC) are integrated into the UAV cluster. We analytically derive the piecewise probability density function for the FSO link distance, obtaining exact closed-form expressions for the end-to-end secrecy outage probability (SOP). Monte Carlo simulations strictly validate the derivations. The results demonstrate that while increasing available relays and antennas enhances PLS via spatial diversity, a security bottleneck restricts the RF-FSO architecture under high-transmit power regimes, generating asymptotic secrecy floors. These findings provide explicit theoretical guidelines for the secure design and parameter optimization of future SAGINs. Full article
(This article belongs to the Section Astronautics & Space Science)
Show Figures

Figure 1

19 pages, 589 KB  
Article
The Body Underground: A Biological Framework for Infrastructure Health, Regulation and Resilience
by Priscilla Nelson and Richard Little
Urban Sci. 2026, 10(4), 201; https://doi.org/10.3390/urbansci10040201 - 4 Apr 2026
Viewed by 180
Abstract
Underground infrastructure systems are typically managed as discrete technical assets rather than as integrated, adaptive systems. This paper develops the Body Underground framework, a structured biological analogy that synthesizes prior clinical and epidemiological metaphors into a multiscale conceptual model linking materials, facilities, networks, [...] Read more.
Underground infrastructure systems are typically managed as discrete technical assets rather than as integrated, adaptive systems. This paper develops the Body Underground framework, a structured biological analogy that synthesizes prior clinical and epidemiological metaphors into a multiscale conceptual model linking materials, facilities, networks, and governance. Building on Little’s clinical framing of infrastructure health and Bardet and Little’s epidemiological analysis of network failure clustering, the framework extends biological interpretation to anatomical, physiological, and homeostatic scales. The approach maps structural, hydraulic, sensing, protective, and regulatory functions to functional equivalents in living systems using explicit criteria of feedback, regulation, and measurability. The central objective of the study is to determine whether biological regulatory concepts—particularly homeostasis and hierarchical organization—can provide a coherent interpretive structure for understanding infrastructure health across material, facility, network, and governance scales. The resulting framework reframes resilience as dynamic regulatory balance rather than static robustness alone. It clarifies the methodological basis for constructing biological–infrastructure analogies, identifies measurable “vital signs” for infrastructure health, and outlines pathways toward operational translation through integrated monitoring and governance feedback. While conceptual in nature, the framework provides a structured synthesis linking material science, infrastructure engineering, systems resilience theory, and policy coordination. By organizing resilience concepts through cross-scale regulatory logic, the Body Underground model offers a coherent structure for integrating monitoring, diagnosis, and governance in the proactive management of underground infrastructure systems. Full article
Show Figures

Figure 1

28 pages, 2083 KB  
Article
Agrarian Structure in a Small Island Region: A Typological and Spatial Analysis of Agricultural Systems in Madeira Island
by Matheus Koengkan, José Alberto Fuinhas and Iyabo Olanrele
Sustainability 2026, 18(7), 3545; https://doi.org/10.3390/su18073545 - 3 Apr 2026
Viewed by 302
Abstract
Madeira’s agricultural sector is characterised by pronounced structural heterogeneity, land fragmentation, and increasing socio-economic and environmental pressures. However, comprehensive typological and spatial analyses remain limited, particularly in small island contexts. This study addresses this gap by providing a typological and spatial analysis of [...] Read more.
Madeira’s agricultural sector is characterised by pronounced structural heterogeneity, land fragmentation, and increasing socio-economic and environmental pressures. However, comprehensive typological and spatial analyses remain limited, particularly in small island contexts. This study addresses this gap by providing a typological and spatial analysis of the agrarian structure in the Autonomous Region of Madeira, Portugal, using 2019 Agricultural Census data. An integrated framework combining Principal Component Analysis (PCA), Partitioning Around Medoids (PAM) clustering, and Random Forest validation—representing a novel approach in agrarian typology studies—is employed to identify three agricultural models: Intensive Subtropical Agriculture (24.1% of parishes), characterised by small holdings and high labour intensity; Extensive Traditional Agriculture (64.8%), featuring moderate farm size and diversified cropping; and Pasture-based Agriculture (11.1%), dominated by larger farms and low labour input. The results confirm significant structural trade-offs, including a strong inverse relationship between farm size and labour intensity (r = −0.653) and a negative correlation between specialisation and crop diversity (r = −0.673). Spatially, the models exhibit clear territorial differentiation, with subtropical systems concentrated in southern coastal areas and traditional systems prevailing in northern and interior regions. These findings support the hypothesis of a hybrid agrarian transition. Despite relying on cross-sectional data, the results provide a robust basis for targeted and place-based policy design within the Common Agricultural Policy (CAP) framework. Full article
Show Figures

Figure 1

29 pages, 2329 KB  
Article
Stochastic Optimal Scheduling of an Integrated Energy System with Thermoelectric Decoupling and Ammonia Co-Firing Considering Energy Storage Capacity Leasing
by Bo Fu and Zhongxi Wu
Energies 2026, 19(7), 1774; https://doi.org/10.3390/en19071774 - 3 Apr 2026
Viewed by 190
Abstract
To address the problem of renewable energy curtailment and the need for operational economic optimization in integrated energy systems with high penetration of wind and solar power, a coordinated optimization method integrating thermoelectric decoupling, ammonia-blended combustion technology, and energy storage capacity leasing is [...] Read more.
To address the problem of renewable energy curtailment and the need for operational economic optimization in integrated energy systems with high penetration of wind and solar power, a coordinated optimization method integrating thermoelectric decoupling, ammonia-blended combustion technology, and energy storage capacity leasing is proposed. First, a chaotic-improved Latin Hypercube Sampling (C-LHS) method, combined with an improved K-means clustering algorithm, is employed to generate representative wind–solar–load scenarios. This approach improves the efficiency of uncertainty scenario generation while reducing computational burden and maintaining solution accuracy. Secondly, by coordinating the operation of thermal energy storage and electric boilers, the “heat-led power generation” constraint is relaxed, and, in combination with ammonia-blended combustion in combined heat and power (CHP) units, the system’s flexibility and renewable energy accommodation capability are enhanced. Finally, with the objective of minimizing total operating cost, a day-ahead scheduling model incorporating electrical energy storage (EES) leasing optimization is established. For EES, under a shared energy storage market mechanism, the golden section search (GSS) algorithm is employed to optimize the day-ahead leasing capacity. The simulation results demonstrate that the proposed method improves renewable energy accommodation while maintaining economic performance, and effectively reduces the overall operating cost of the system. These findings confirm the effectiveness of the proposed strategy in enhancing both system flexibility and economic performance. Full article
(This article belongs to the Section F2: Distributed Energy System)
Show Figures

Figure 1

Back to TopTop