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12 pages, 300 KB  
Article
On Syntactical Simplification of Temporal Operators in Negation-Free Metric Temporal Logic
by Mathijs van Noort, Femke Ongenae and Pieter Bonte
Mathematics 2026, 14(7), 1124; https://doi.org/10.3390/math14071124 - 27 Mar 2026
Abstract
Temporal reasoning in dynamic, data-intensive environments increasingly demands expressive yet tractable logical frameworks. Traditional approaches often rely on negation to express absence or contradiction. In such contexts, negation-as-failure is commonly used to infer negative information from the lack of positive evidence. However, for [...] Read more.
Temporal reasoning in dynamic, data-intensive environments increasingly demands expressive yet tractable logical frameworks. Traditional approaches often rely on negation to express absence or contradiction. In such contexts, negation-as-failure is commonly used to infer negative information from the lack of positive evidence. However, for open and distributed systems such as IoT networks and the Semantic Web, negation-as-failure semantics become unreliable due to incomplete and asynchronous data. This has led to growing interest in negation-free fragments of temporal rule-based systems, which preserve monotonicity and enable scalable reasoning. This paper investigates the expressive power of negation-free Metric Temporal Logic (MTL), a temporal logic framework designed for rule-based reasoning over time. We show that the “always” operators ⊞ and ⊟, often treated as syntactic sugar for combinations of other temporal constructs, can be eliminated using “once”, “since” and “until” operators. Remarkably, even the “once” operators can be removed, yielding a fragment based solely on “until” and “since”. These results challenge the assumption that negation is necessary for expressing universal temporal constraints and reveal a robust fragment capable of capturing both existential and invariant temporal patterns. Furthermore, the results induce a reduction in the syntax of MTL, which, in turn, can provide benefits for both theoretical study as well as for implementation efforts. Full article
(This article belongs to the Special Issue Formal Methods in Computer Science: Theory and Applications)
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25 pages, 1530 KB  
Article
FocuS-MN: Focusing on Underwater Signal Denoising via Sequential Memory Networks with Learnable Resampling
by Shouao Gu, Zitong Li and Jun Tang
J. Mar. Sci. Eng. 2026, 14(7), 621; https://doi.org/10.3390/jmse14070621 - 27 Mar 2026
Abstract
The coupling of non-stationary marine noise and complex ship-radiated signals makes high-fidelity signal recovery exceptionally difficult. Existing deep learning methods often prioritize objective metrics, such as the Scale-Invariant Signal-to-Noise Ratio (SI-SNR), but fail to maintain the integrity of narrow-band line spectral data. We [...] Read more.
The coupling of non-stationary marine noise and complex ship-radiated signals makes high-fidelity signal recovery exceptionally difficult. Existing deep learning methods often prioritize objective metrics, such as the Scale-Invariant Signal-to-Noise Ratio (SI-SNR), but fail to maintain the integrity of narrow-band line spectral data. We propose FocuS-MN, an end-to-end framework that combines learnable resampling with Feedforward Sequential Memory Network (FSMN)-based temporal modeling for precise waveform reconstruction. The model is optimized using a two-stage training strategy to ensure stable magnitude estimation and waveform consistency. On the ShipsEar dataset, FocuS-MN shows strong generalization to unseen vessel types. At a −5 dB Signal-to-Noise Ratio (SNR), it achieves a Signal-to-Distortion Ratio (SDR) of 3.77 dB and a Segmental Signal-to-Noise Ratio (SSNR) of 3.83 dB. Power Spectral Density (PSD) analysis further confirms that FocuS-MN recovers fine-grained line spectral structures, proving its effectiveness in both noise suppression and signal fidelity. Full article
(This article belongs to the Section Ocean Engineering)
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33 pages, 15024 KB  
Article
HFA-Net: Explainable Multi-Scale Deep Learning Framework for Illumination-Invariant Plant Disease Diagnosis in Precision Agriculture
by Muhammad Hassaan Ashraf, Farhana Jabeen, Muhammad Waqar and Ajung Kim
Sensors 2026, 26(7), 2067; https://doi.org/10.3390/s26072067 - 26 Mar 2026
Abstract
Robust plant disease detection in real-world agricultural environments remains challenging due to dynamic environmental conditions. Accurate and reliable disease identification is essential for precision agriculture and effective crop management. Although computer vision and Artificial Intelligence (AI) have shown promising results in controlled settings, [...] Read more.
Robust plant disease detection in real-world agricultural environments remains challenging due to dynamic environmental conditions. Accurate and reliable disease identification is essential for precision agriculture and effective crop management. Although computer vision and Artificial Intelligence (AI) have shown promising results in controlled settings, their performance often drops under lesion scale variability, inter- and intra-class similarity among diseases, class imbalance, and illumination fluctuations. To overcome these challenges, we propose a Heterogeneous Feature Aggregation Network (HFA-Net) that brings together architectural improvements, illumination-aware preprocessing, and training-level enhancements into a single cohesive framework. To extract richer and more discriminative features from the early layers of the network, HFA-Net introduces a multi-scale, multi-level feature aggregation stem. The Reduction-Expansion (RE) mechanism helps preserve important lesion details while adapting to variations in scale. Considering real agricultural environments, an Illumination-Adaptive Contrast Enhancement (IACE) preprocessing pipeline is designed to address illumination variability in real agricultural environments. Experimental results show that HFA-Net achieves 96.03% accuracy under normal conditions and maintains strong performance under challenging lighting scenarios, achieving 92.95% and 93.07% accuracy in extremely dark and bright environments, respectively. Furthermore, quantitative explainability analysis using perturbation-based metrics demonstrates that the model’s predictions are not only accurate but also faithful to disease-relevant regions. Finally, Grad-CAM-based visual explanations confirm that the model’s predictions are driven by disease-specific regions, enhancing interpretability and practical reliability. Full article
(This article belongs to the Section Smart Agriculture)
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17 pages, 342 KB  
Article
Optimality of Quantum Adiabatic Search Algorithm and Its Circuit Model
by Jie Sun, Zhimin Zhang and Songfeng Lu
Quantum Rep. 2026, 8(2), 28; https://doi.org/10.3390/quantum8020028 - 26 Mar 2026
Viewed by 31
Abstract
In this paper, we study two aspects of quantum adiabatic evolution for a prototypical search problem: the optimality of the corresponding algorithm and its relation to the quantum circuit model. Firstly, we propose a general framework for proving the square-root speedup of the [...] Read more.
In this paper, we study two aspects of quantum adiabatic evolution for a prototypical search problem: the optimality of the corresponding algorithm and its relation to the quantum circuit model. Firstly, we propose a general framework for proving the square-root speedup of the quantum adiabatic algorithm to be optimal over classical computation, which is readily applicable to the case of multiple targets. Through this framework, we also find that it is possible to further reduce the time complexity by increasing the physical energy of the system, encompassing results from previous works. Secondly, we find that, on the one hand, when the quantum adiabatic algorithm that achieves quadratic speedup is implemented on a quantum circuit, the time slice needed is always consistent with its time complexity, which also encompasses previous results; on the other hand, however, if a further algorithmic improvement is considered, the time slice always remains invariant. This phenomenon represents a significant observation with potential applications. We anticipate that the main results of this paper will interest the quantum adiabatic computation community and may help us to design efficient quantum algorithms for practical problems in the future. Full article
14 pages, 3036 KB  
Article
A Study on the Impact of Sunlight, Ultraviolet Radiation, and Temperature Variability on COVID-19 Mortality: Spatiotemporal Evidence from Small Countries and U.S. States and Territories
by Murat Razi and Manuel Graña
COVID 2026, 6(4), 56; https://doi.org/10.3390/covid6040056 - 26 Mar 2026
Viewed by 90
Abstract
Objectives: While the previous literature has established that meteorological conditions are associated with COVID-19 mortality fluctuations, the relative effect of each of these highly correlated factors remains unclear. This study aims to conduct a comparative analysis to determine which of three main meteorological [...] Read more.
Objectives: While the previous literature has established that meteorological conditions are associated with COVID-19 mortality fluctuations, the relative effect of each of these highly correlated factors remains unclear. This study aims to conduct a comparative analysis to determine which of three main meteorological variables—Ambient Temperature, Ultraviolet (UV) Index, and Sunlight Duration—have the strongest negative association with COVID-19 mortality. The objective is to quantify and rank their impact over a 7-to-21-day biological exposure window. Methods: We conducted retrospective spatiotemporal analyses in the form of panel Poisson Distributed Lag Models (PDLMs) regression using daily data from 21 January 2020 to 10 January 2023, spanning 129 distinct geographical regions worldwide. To ensure a direct and fair comparison of effect sizes, all meteorological and environmental variables were Z-score standardized. We estimated three independent PDLMs—each focusing separately on UV Index, Ambient Temperature, and Sunlight Duration—with lags ranging from 7 to 21 days. These models controlled for overarching time trends and utilized a categorical variable to account for Region Fixed Effects modeling time-invariant regional health and socioeconomic determinants (e.g., obesity, age demographics, healthcare capacity). Furthermore, distributed lags of daily PM2.5 (air pollution) and relative humidity were explicitly included in each model as dynamic confounders. Results: The comparison of PDLM results reveals that the UV Index has the strongest negative association with COVID-19 mortality. A one standard deviation increase in the UV Index corresponds to a massive, highly significant cumulative reduction in deaths observed 1 to 3 weeks later (p < 0.001). Sunlight Duration is the second-strongest protective meteorological factor, whereas Ambient Temperature has the weakest effect. The distributed lags of particulate matter (PM2.5) and relative humidity were found to be statistically insignificant when modeled alongside the meteorological variables. Conclusions: After standardizing variables and controlling for dynamic environmental confounders like air pollution and humidity, the study findings provide robust empirical evidence that meteorological conditions have a strong significant association with COVID-19 mortality fluctuation with a temporal delay, overcoming the confounding effects of merely dry or clear-air conditions. Full article
(This article belongs to the Section COVID Clinical Manifestations and Management)
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29 pages, 4764 KB  
Article
A Two-Level Illumination Correction Network for Digital Meter Reading Recognition in Non-Uniform Low-Light Conditions
by Haoning Fu, Zhiwei Xie, Wenzhu Jiang, Xingjiang Ma and Dongying Yang
J. Imaging 2026, 12(4), 146; https://doi.org/10.3390/jimaging12040146 - 25 Mar 2026
Viewed by 91
Abstract
The automatic reading recognition of digital instruments is crucial for achieving metering automation and intelligent inspection. However, in non-standardized industrial environments, the masking effect caused by the coupling of non-uniform low-light conditions and the reflective surfaces of instrument panels severely degrades the displayed [...] Read more.
The automatic reading recognition of digital instruments is crucial for achieving metering automation and intelligent inspection. However, in non-standardized industrial environments, the masking effect caused by the coupling of non-uniform low-light conditions and the reflective surfaces of instrument panels severely degrades the displayed information, significantly limiting the recognition performance. Conventional image processing methods, while aiming to restore the imaging quality of instrument panels through low-light enhancement, inevitably introduce overexposure and indiscriminately amplify background noise during this process. To address the two key challenges of illumination recovery and noise suppression in the process of restoring panel image quality under non-uniform low-light conditions, this paper proposes a coarse-to-fine cascaded perception framework (CFCP). First, a lightweight YOLOv10 detector is employed to coarsely localize the meter reading region under non-uniform illumination conditions. Second, an Adaptive Illumination Correction Module (AICM) is designed to decouple and correct the illumination component at the pixel level, effectively restoring details in dark areas. Then, an Illumination-invariant Feature Perception Module (IFPM) is embedded at the feature level to dynamically perceive illumination-invariant features and filter out noise interference. Finally, the refined detection results are fed into a lightweight sequence recognition network to obtain the final meter readings. Experiments on a self-built industrial digital instrument dataset show that the proposed method achieves 93.2% recognition accuracy, with 17.1 ms latency and only 7.9 M parameters. Full article
(This article belongs to the Special Issue AI-Driven Image and Video Understanding)
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41 pages, 447 KB  
Article
An Approach to Fisher-Rao Metric for Infinite Dimensional Non-Parametric Information Geometry
by Bing Cheng and Howell Tong
Entropy 2026, 28(4), 374; https://doi.org/10.3390/e28040374 - 25 Mar 2026
Viewed by 119
Abstract
Non-parametric information geometry has long faced an “intractability barrier”: in the infinite-dimensional setting, the Fisher–Rao metric is a weak Riemannian metric functional that lacks a bounded inverse, rendering classical optimization and estimation techniques computationally inaccessible. This paper resolves this barrier by building the [...] Read more.
Non-parametric information geometry has long faced an “intractability barrier”: in the infinite-dimensional setting, the Fisher–Rao metric is a weak Riemannian metric functional that lacks a bounded inverse, rendering classical optimization and estimation techniques computationally inaccessible. This paper resolves this barrier by building the statistical manifold on the Orlicz space L0Φ(Pf) (the Pistone–Sempi manifold), which provides the necessary exponential integrability for score functions and a rigorous Fréchet differentiability for the Kullback–Leibler divergence. We introduce a novel Structural Decomposition of the Tangent Space (TfM=SS), where the infinite-dimensional space is split into a finite-dimensional covariate subspace (S)—representing the observable system—and its orthogonal complement (S). Through this decomposition, we derive the Covariate Fisher Information Matrix (cFIM), denoted as Gf, which acts as the computable “Hilbertian slice” of the otherwise intractable metric functional. Key theoretical contributions include proving the Trace Theorem (HG(f)=Tr(Gf)) to identify G-entropy as a fundamental geometric invariant; demonstrating the Geometric Invariance of the Covariate Fisher Information Matrix (cFIM) as a covariant (0,2)-tensor under reparameterization; establishing the cFIM as the local Hessian of the KL-divergence; and characterizing the Efficiency Standard through a generalized Cramer–Rao Lower Bound for semi-parametric inference within the Orlicz manifold. Furthermore, we demonstrate that this framework provides a formal mathematical justification for the Manifold Hypothesis, as the structural decomposition naturally identifies the low-dimensional subspace where information is concentrated. By shifting the focus from the intractable global manifold to the tractable covariate geometry, this framework proves that statistical information is not a property of data alone, but an active geometric interaction between the environment (data), the system (covariate subspace), and the mechanism (Fisher–Rao connection). Full article
21 pages, 278 KB  
Article
Tone as Ontology: A Structural Account of Being Grounded in Generative Invariants
by Jonah Y. C. Hsu
Philosophies 2026, 11(2), 49; https://doi.org/10.3390/philosophies11020049 (registering DOI) - 25 Mar 2026
Viewed by 172
Abstract
This paper develops Tone as Ontology, a structural account of being grounded in the invariants of generative systems. We articulate the ontological significance of tone, distinguishing this foundational work from a companion paper that explores its methodological application and formalization. We redefine “tone” [...] Read more.
This paper develops Tone as Ontology, a structural account of being grounded in the invariants of generative systems. We articulate the ontological significance of tone, distinguishing this foundational work from a companion paper that explores its methodological application and formalization. We redefine “tone” as the structural profile of constraints that allows entities to maintain coherence under transformation. The tonal ontology formalizes three invariants—Resonance, Responsibility, and Closure—as conditions of persistence that bridge operational and metaphysical ontology. Concretely, we specify Resonance (relational continuity via recursive feedback), Responsibility (traceable accountability that conserves integrity across transformations), and Closure (recursive self-consistency enabling bounded openness). In contrast to informational or substance-based views, tonal being is understood as the conservation of structure through change. The resulting framework unites physical coherence, informational integrity, and ontological continuity into a generative ontology of integrity, suggesting that to exist is to maintain one’s tone. This paper addresses fundamental questions in meta-ontology, demonstrates how tone generates classical ontological frameworks, and advances a conceptual reorientation for understanding existence as resonant persistence. It outlines testable implications across philosophy of mind, AI ethics, and social/environmental theory. Overall, tonal ontology is presented as a post-informational, structurally grounded account of being. Full article
15 pages, 46451 KB  
Article
Parameter Optimization for Torsion-Balance Experiments Testing d = 6 Lorentz-Violating Effects in the Pure-Gravity Sector
by Tao Jin, Pan-Pan Wang, Weisheng Huang, Rui Luo, Yu-Jie Tan and Cheng-Gang Shao
Symmetry 2026, 18(4), 559; https://doi.org/10.3390/sym18040559 (registering DOI) - 25 Mar 2026
Viewed by 156
Abstract
Local Lorentz Invariance is one of the fundamental postulates of General Relativity, making its experimental verification of paramount importance. Given that various frontier theoretical models predict potential symmetry breaking, the Standard Model Extension framework has been established to systematically study such phenomena. Within [...] Read more.
Local Lorentz Invariance is one of the fundamental postulates of General Relativity, making its experimental verification of paramount importance. Given that various frontier theoretical models predict potential symmetry breaking, the Standard Model Extension framework has been established to systematically study such phenomena. Within the Standard Model Extension gravitational sector, the high-order Lorentz-violating terms with mass dimension d=6 exhibit a rapid signal decay with distance, providing a distinct detection advantage in short-range gravity experiments. This work is dedicated to optimizing the testing schemes for d=6 Lorentz-violating coefficients. Based on a high-precision torsion balance platform, we propose a novel scheme featuring a comb-stripe design. The improvements are twofold: first, the spatial orientation of the experimental apparatus is optimized to leverage the modulation effects of the Earth’s rotation, thereby enhancing the capability to distinguish and constrain different violation parameters; second, the test and source masses are reconfigured into specifically designed stripe patterns to significantly amplify the fringe-field signals sensitive to Lorentz-violating effects. This paper systematically elaborates on the theoretical foundation and design principles of the new scheme. By performing a detailed comparison of the constraint potentials of various stripe configurations, the five-stripe geometry is identified as the optimal experimental configuration. This study provides a new experimental methodology for exploring physics beyond the Standard Model at higher levels of precision. Full article
(This article belongs to the Section Physics)
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22 pages, 1920 KB  
Article
Nonlinear Analytical Design of Nonlinear Tuned Mass Dampers and Nonlinear Primary Structures Based on Complex Variable Averaging and Multiscale Methods
by Qing Zhang, Ji Yao, Yujie Wang and Xiuping Zhang
Buildings 2026, 16(7), 1290; https://doi.org/10.3390/buildings16071290 - 25 Mar 2026
Viewed by 105
Abstract
With the development of modern structures in the direction of higher and more complexity, the existence of multiple factors in the design and requirements of structures can lead to structures prone to nonlinear properties. The tuned mass damper (TMD), a widely implemented passive [...] Read more.
With the development of modern structures in the direction of higher and more complexity, the existence of multiple factors in the design and requirements of structures can lead to structures prone to nonlinear properties. The tuned mass damper (TMD), a widely implemented passive control mechanism, plays a crucial role in the engineering field by effectively reducing vibrations within primary structures. Nevertheless, its deployment frequently induces nonlinear dynamics due to the substantial displacements resulting from TMD operation or the integration of limiting devices. This research delineates a computational framework for a single-degree-of-freedom nonlinear primary system regulated by a nonlinear tuned mass damper (NTMD), designed to emulate near-fault seismic phenomena via a sinusoidal load. The study concentrates on the nonlinear attributes of both the NTMD and the primary system. Utilizing the complex variable averaging method in conjunction with the multiscale technique, complex variable equations and slow invariant manifolds are formulated for the system under 1:1 resonance conditions, with their accuracy and validity substantiated through numerical simulations. Expanding upon the derived complex variable equations and slow invariant manifolds, this study examines the impact of nonlinear coefficients within the NTMD and the primary system on both the damping performance of the NTMD and the stability of the primary system. Furthermore, this research delves into the effects of mass ratio fluctuations on the damping effectiveness of the TMD and the control efficiency of the primary system, as well as the emergence of jump phenomena in the presence of significant nonlinear coefficients. The analytical outcomes underscore the critical need to account for the inherent nonlinearities in both the TMD and the primary system, which can have detrimental effects. By considering the mass ratio as a key design parameter, optimizing it can enhance the TMD’s vibration suppression capabilities and the primary system’s control behavior, while also reducing the likelihood of jump phenomena and improving overall structural stability. Full article
(This article belongs to the Special Issue Building Safety Assessment and Structural Analysis)
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15 pages, 4471 KB  
Article
Facile One-Pot Synthesis of Au/Ag Bimetallic Nanoclusters as a Fluorescent Probe for the Detection of Hg2+ and Cu2+
by Hongbo Lin, Taiqun Yang, Lei Li and Lang Liu
Chemosensors 2026, 14(4), 78; https://doi.org/10.3390/chemosensors14040078 - 25 Mar 2026
Viewed by 174
Abstract
Fluorescent metal nanoclusters show great promise in heavy metal ion sensing. Herein, a bimetallic nanocluster (GSH-Au/Ag NCs) with orange fluorescence was synthesized through a facile one-pot method. The synthesized GSH-Au/Ag NCs displayed optimal excitation and emission peaks at 275 and 610 nm, respectively. [...] Read more.
Fluorescent metal nanoclusters show great promise in heavy metal ion sensing. Herein, a bimetallic nanocluster (GSH-Au/Ag NCs) with orange fluorescence was synthesized through a facile one-pot method. The synthesized GSH-Au/Ag NCs displayed optimal excitation and emission peaks at 275 and 610 nm, respectively. The incorporation of silver can enhance the fluorescence of metal nanoclusters. The fluorescence of as-synthesized GSH-Au/Ag NCs can be significantly quenched by Hg2+ and Cu2+, and a “on–off” fluorescent probe was designed. The detection conditions, including pH and the concentration of the probe, were optimized. The respective detection limits for Hg2+ and Cu2+ ions under optimal detection conditions are estimated to be 40 nM and 33 nM, over the linear range of 100–1200 nM. Furthermore, a ratiometric fluorescent probe was prepared by mixing quinine sulfate and as-synthesized GSH-Au/Ag NCs. Hg2+ and Cu2+ can effectively quench the red fluorescence of GSH-Au/Ag NCs, whereas the blue fluorescence of quinine sulfate remains invariant. This leads to measurable changes in the RGB values of the resulting fluorescence images. The ratio (R/B) exhibits a linear relationship with the concentration of Hg2+ and Cu2+, enabling the determination of its concentration by analyzing RGB values in fluorescence images. This visual detection method significantly reduces both assay time and cost, making it suitable for on-site detection of heavy metal ions in water samples. Full article
(This article belongs to the Section Nanostructures for Chemical Sensing)
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19 pages, 5230 KB  
Article
Global Linearized Sparse Prediction and Adaptive Dead Zone Compensation for a Piezoelectric Actuator
by Xue Qi, Meiting Zhao, Lina Zhang, Lei Fan, Zhihui Liu, Pengying Xu and Qiulin Tan
Micromachines 2026, 17(4), 392; https://doi.org/10.3390/mi17040392 - 24 Mar 2026
Viewed by 51
Abstract
A piezoelectric actuator (PEA) is a fundamental part of a high-precision motion system, yet its performance is critically constrained by inherent nonlinearities such as the velocity dead zone and hysteresis. To overcome these limitations and the associated time-varying dynamics, this study introduces a [...] Read more.
A piezoelectric actuator (PEA) is a fundamental part of a high-precision motion system, yet its performance is critically constrained by inherent nonlinearities such as the velocity dead zone and hysteresis. To overcome these limitations and the associated time-varying dynamics, this study introduces a novel control framework for a dual-mode standing wave PEA. The framework integrates a Global Linearized Sparse Prediction (GLSP) model with an Adaptive Kalman Observer-based Model Predictive Control (AKOBMPC) strategy, specifically designed for velocity dead-zone compensation. The GLSP model employs Koopman operator theory to lift the complex, nonlinear electromechanical and contact dynamics into a linear invariant subspace. Incorporated with a deep learning-based structured pruning mechanism, the model achieves an effective balance between prediction accuracy and computational efficiency, facilitating real-time implementation. Leveraging this high-fidelity model, the AKOBMPC algorithm is developed to estimate unmeasurable disturbances and optimize the control sequence for precise velocity tracking. Experimental results demonstrate the GLSP model’s accurate prediction of system behavior under varying loads and excitation frequencies. The proposed controller effectively suppresses the velocity dead zone, achieving tracking errors within ±0.35 mm/s for a 40.00 mm/s trapezoidal reference and within ±0.50 mm/s for sinusoidal tracking. These results confirm the superior performance of the AKOBMPC scheme over conventional methods, offering a robust solution for high-precision velocity regulation in PEA system and contributing to the advancement of next-generation precision actuator. Full article
(This article belongs to the Special Issue Micro/Nanostructures in Sensors and Actuators, 2nd Edition)
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103 pages, 2567 KB  
Article
Thermodynamics à la Souriau on Kähler Non-Compact Symmetric Spaces for Cartan Neural Networks
by Pietro G. Fré, Alexander S. Sorin and Mario Trigiante
Entropy 2026, 28(4), 365; https://doi.org/10.3390/e28040365 - 24 Mar 2026
Viewed by 52
Abstract
In this paper, we clarify several issues concerning the abstract geometrical formulation of thermodynamics on non-compact symmetric spaces U/H that are the mathematical model of hidden layers in the new paradigm of Cartan Neural Networks. We introduce a clear-cut distinction between [...] Read more.
In this paper, we clarify several issues concerning the abstract geometrical formulation of thermodynamics on non-compact symmetric spaces U/H that are the mathematical model of hidden layers in the new paradigm of Cartan Neural Networks. We introduce a clear-cut distinction between the generalized thermodynamics associated with Integrable Dynamical Systems and the challenging proposal of Gibbs probability distributions on U/H provided by generalized thermodynamics à la Souriau. Our main result is the proof that U/H.s supporting such Gibbs distributions are only the Kähler ones. Furthermore, for the latter, we solve the problem of determining the space of temperatures, namely, of Lie algebra elements for which the partition function converges. The space of generalized temperatures is the orbit under the adjoint action of U of a positivity domain in the Cartan subalgebra CcH of the maximal compact subalgebra HU. We illustrate how our explicit constructions for the Poincaré and Siegel planes might be extended to the whole class of Calabi–Vesentini manifolds utilizing Paint Group symmetry. Furthermore, we claim that Rao’s, Chentsov’s, and Amari’s Information Geometry and the thermodynamical geometry of Ruppeiner and Lychagin are the very same thing. In particular, we provide an explicit study of thermodynamical geometry for the Poincaré plane. The key feature of the Gibbs probability distributions in this setup is their covariance under the entire group of symmetries U. The partition function is invariant against U transformations, and the set of its arguments, namely the generalized temperatures, can always be reduced to a minimal set whose cardinality is equal to the rank of the compact denominator group HU. Full article
(This article belongs to the Collection Feature Papers in Information Theory)
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18 pages, 4538 KB  
Article
Analytical-Numerical Modeling of Filling-Fraction-Dependent Plasmonic Coupling in Nanostructured Metasurfaces Under Kretschmann Configuration
by Karan K. Singh, Guillermo E. Sánchez-Guerrero, Perla M. Viera-González, Carlos A. Fuentes-Hernandez, María T. Romero de la Cruz, Eduardo Martínez-Guerra, Rodolfo Cortés-Martínez and Edgar Martínez-Guerra
Optics 2026, 7(2), 22; https://doi.org/10.3390/opt7020022 - 24 Mar 2026
Viewed by 93
Abstract
Surface plasmon resonance (SPR) sensors based on nanostructured metasurfaces offer enhanced sensitivity through engineered electromagnetic responses. In this study, we present an analytical and numerical investigation of the plasmonic behavior of gold nanopillar (Au-NP) and nanohole (Au-NH) arrays under both p- and [...] Read more.
Surface plasmon resonance (SPR) sensors based on nanostructured metasurfaces offer enhanced sensitivity through engineered electromagnetic responses. In this study, we present an analytical and numerical investigation of the plasmonic behavior of gold nanopillar (Au-NP) and nanohole (Au-NH) arrays under both p- and s-polarized illumination, employing the Effective Medium Theory (EMT) in combination with the Transfer Matrix Method (TMM). The study combines Effective Medium Theory (EMT) and the Transfer Matrix Method (TMM) to describe the macroscopic optical response of multilayer plasmonic systems. For p-polarization, the nanostructure geometry strongly modulates the real and imaginary parts of the effective permittivity, with nanoholes supporting stronger SPR coupling and reduced optical losses compared to nanopillars. Under s-polarization, the effective permittivity remains largely invariant, primarily driven by the filling fraction. The analysis reveals that polarization-dependent behavior arises from boundary-condition-mediated coupling mechanisms governing surface plasmon excitation, aligning with classical plasmonic theory. Benchmarking against analytical dispersion relations and published experimental data for Au/BK7 systems shows close agreement within ±2°, confirming the physical consistency of the EMT–TMM framework. These results provide a systematic description of how polarization and filling fraction jointly modulate SPR coupling. The results offer a foundation for the rational design of plasmonic coatings and SPR-supporting metasurfaces by elucidating macroscopic coupling trends; however, no quantitative sensor performance metrics, such as refractive index sensitivity or figure of merit, are evaluated in this work. Full article
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19 pages, 874 KB  
Review
Medical Emergencies and Operational Preparedness Among Dentists: A Scoping Review
by Radu-Alexandru Iacobescu, Teofil Blaga, Raluca Dragomir, Ștefania-Crina Mihai, Petruța Moroșan and Anca Hăisan
Dent. J. 2026, 14(4), 190; https://doi.org/10.3390/dj14040190 - 24 Mar 2026
Viewed by 126
Abstract
Background: Medical emergencies occur at varying rates across the globe. Given the significant effort invested in identifying them and assessing dentists’ preparedness to deliver treatment in these life-threatening conditions, a global overview was needed. Materials and Methods: In this scoping review, [...] Read more.
Background: Medical emergencies occur at varying rates across the globe. Given the significant effort invested in identifying them and assessing dentists’ preparedness to deliver treatment in these life-threatening conditions, a global overview was needed. Materials and Methods: In this scoping review, data from PubMed, Cochrane Library, and Google Scholar databases were examined to identify all relevant studies reporting on the impact of medical emergencies on dentists and determine their operational preparedness at a national or regional level. Operational preparedness was determined in accordance with existing emergency operational preparedness frameworks across six domains: Anticipate, Assess, Prevent, Prepare, Respond, and Recover. Significant Findings: Global data show that dentists will invariably encounter medical emergencies across their careers. However, our investigation found that in countries where there is strong foundational training and regular refresher training, fewer frequent emergencies and stronger operational preparedness are reported. Governmental regulation emerged as a key facilitator of operational preparedness. Still, barriers exist, primarily limited access to medical emergency courses, shortages of office supplies for emergency drugs and materials, and the absence of medical emergency registries. Conclusions: A reassessment of the medical emergency training courses’ content appropriateness is paramount. Training interventions should also focus on raising awareness about the importance of preventive measures and office optimization through planning. Further research is needed to identify any overlooked facilitators and barriers to operational preparedness in medical emergencies. This will help identify opportunities for improvement and minimize the impact of emergencies on dental practices. Full article
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