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Search Results (188)

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Keywords = semi-analytical algorithms

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18 pages, 265 KB  
Article
Human Competencies at the Edge of Automation: A Qualitative Study of AI Integration in Frontline Journalism
by Hyeyun Jung
Journal. Media 2026, 7(2), 82; https://doi.org/10.3390/journalmedia7020082 - 14 Apr 2026
Viewed by 282
Abstract
The integration of AI into journalism has intensified debates about the future of news production, yet existing scholarship has focused predominantly on AI’s capabilities rather than on irreplaceable human competencies. This study shifts analytical focus from replacement to complementarity, investigating the boundaries of [...] Read more.
The integration of AI into journalism has intensified debates about the future of news production, yet existing scholarship has focused predominantly on AI’s capabilities rather than on irreplaceable human competencies. This study shifts analytical focus from replacement to complementarity, investigating the boundaries of AI through the perspectives of both journalists and AI developers. Ten participants—including field reporters, news anchors, broadcast journalists, and AI developers—were interviewed through in-depth, semi-structured interviews. Thematic analysis revealed three core dimensions of irreplaceable human competency: embodied presence and rapport-building, contextual judgment and meaning-making, and investigative initiative requiring moral agency. Practitioners and developers converged on AI’s persistent limitations in factual reliability, emotional authenticity, and ethical accountability. Based on these findings, a three-tier human–AI collaborative model is proposed, allocating computational tasks to AI while preserving human authority over editorial judgment, source relationships, and ethical decisions. These findings contribute to human–machine communication theory, extend algorithmic journalism literature beyond capability assessments, and offer practical implications for newsroom workflow design, journalism education, and AI governance. Findings are situated within the Korean media context and should be interpreted accordingly, with implications that may extend to other broadcasting-oriented journalism cultures. Full article
(This article belongs to the Special Issue Reimagining Journalism in the Era of Digital Innovation)
44 pages, 2457 KB  
Article
Extreme Deformations and Self-Coupling: An Analytical Approach to Beams Subjected to Complex Follower Loads
by Adrian Ioan Botean
Mathematics 2026, 14(6), 1009; https://doi.org/10.3390/math14061009 - 16 Mar 2026
Viewed by 495
Abstract
This paper presents a systematic application of the Homotopy Perturbation Method (HPM) to the nonlinear static analysis of cantilever beams subjected simultaneously to three coplanar follower loads: an axial force H, a transverse force V, and a bending moment M1. The [...] Read more.
This paper presents a systematic application of the Homotopy Perturbation Method (HPM) to the nonlinear static analysis of cantilever beams subjected simultaneously to three coplanar follower loads: an axial force H, a transverse force V, and a bending moment M1. The studied configuration introduces complex mathematical self-coupling, as the bending moment depends on the solution of the differential equation even in its boundary conditions (γ1), transforming the problem into a nonlinear one that is resistant to standard analytical methods. The primary methodological contribution of this work is the successful extension of the HPM framework to treat, within a unified mathematical formalism, this complete loading case, which has practical applications in compliant mechanisms, micro-electromechanical systems (MEMSs), and auxetic structures. The paper provides a complete mathematical formulation and explicit derivation of the HPM solution terms up to the third order and a rigorous demonstration of the method’s convergence, with quantitative error estimates and the establishment of a practical domain of validity, γ1 < 30°, for an accuracy below 0.5%. As a direct consequence of this analytical advancement, we derive a series of practical engineering tools: nomograms, simplified empirical formulas, interaction diagrams, and a systematic six-step design procedure, which includes an adaptive algorithm for selecting the auxiliary parameter η to optimize convergence. The solution’s structure also lends itself to AI-based optimization frameworks, demonstrating how HPM solutions can serve as a foundation for machine learning surrogates and automated multi-objective optimizations. HPM proves to be a robust and efficient alternative, providing semi-analytical solutions in the form of convergent series without requiring an explicitly small physical parameter. This enables a direct parametric understanding of the structural response and offers rapid tools for the conceptual and preliminary sizing phases, thereby complementing the intensive numerical methods used in the final design stages. Full article
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27 pages, 1101 KB  
Article
Authentic Intelligence in Digital Strategy Systems: A Socio-Technical Analysis of Human-Accountable Decision Governance
by Imo Enang, Patrick Mukala and Ubong Nkereuwem
Systems 2026, 14(3), 259; https://doi.org/10.3390/systems14030259 - 28 Feb 2026
Viewed by 482
Abstract
Background: Digital strategy increasingly relies on algorithmic decision systems, yet the mechanisms by which human judgement remains embedded within these systems are poorly theorised. Existing frameworks treat digital tools as either neutral instruments or autonomous agents, overlooking the systems-level conditions under which human [...] Read more.
Background: Digital strategy increasingly relies on algorithmic decision systems, yet the mechanisms by which human judgement remains embedded within these systems are poorly theorised. Existing frameworks treat digital tools as either neutral instruments or autonomous agents, overlooking the systems-level conditions under which human accountability is maintained. Methods: This study employs a novel three-stage system-oriented analytical protocol: (1) mechanism-revealing thematic analysis of 50 semi-structured interviews with senior managers across multinational organisations; (2) configurational cross-case mapping against 685 cases from the European Commission’s JRC AI implementation catalogue; and (3) failure mode triangulation comparing interview-reported barriers with 37 documented implementation discontinuations. Results: We introduce Authentic Intelligence as a systems-level construct and develop a socio-technical architecture specifying six primary system functions, three decision loci, four governance mechanisms, and twelve empirically derived failure modes. Triangulation reveals high correspondence (≥20% JRC citation rate) for six failure modes and moderate correspondence for six additional modes. Conclusions: The contribution is a reusable systems architecture and diagnostic framework for maintaining human-accountable decision governance in digital strategy implementation, with direct application to EU AI Act Article 14 compliance requirements. Full article
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14 pages, 1814 KB  
Article
Development of a Gold Nanoparticle-Based Amplification-Free Nanobiosensor for Rapid DNA Detection Supported by Machine Learning
by Yunus Aslan, Yeşim Taşkın Korucu, Brad Day and Remziye Yılmaz
Biosensors 2026, 16(2), 128; https://doi.org/10.3390/bios16020128 - 20 Feb 2026
Viewed by 780
Abstract
The global expansion of genetically modified (GM) crop cultivation has increased the demand for analytical platforms that can provide rapid, reliable, and cost-effective detection of GM-derived ingredients to support traceability, regulatory compliance, and accurate labeling. Conventional molecular assays such as polymerase chain reaction [...] Read more.
The global expansion of genetically modified (GM) crop cultivation has increased the demand for analytical platforms that can provide rapid, reliable, and cost-effective detection of GM-derived ingredients to support traceability, regulatory compliance, and accurate labeling. Conventional molecular assays such as polymerase chain reaction (PCR) and isothermal amplification are highly sensitive and specific but depend on sophisticated instrumentation and trained personnel, limiting their applicability in field settings. Here, we present a label-free and amplification-free nanobiosensor based on citrate-capped gold nanoparticles (AuNPs) for the direct colorimetric detection of the Cry1Ac gene associated with the MON87701 soybean event, without the use of polymerase chain reaction (PCR) or any enzymatic nucleic acid amplification step. The assay relies on the localized surface plasmon resonance (LSPR) of AuNPs, which induces a red-to-purple color transition upon hybridization between complementary DNA strands. Critical reaction parameters, including NaCl concentration, AuNP size, and ionic strength, were optimized to enable selective and reproducible aggregation. Integration with a Support Vector Machine (SVM) algorithm enabled automated spectral classification and semi-quantitative discrimination of GM content levels. The optimized AuNP–SVM system achieved high sensitivity (limit of detection ≈ 2.5 ng μL−1, depending on nanoparticle batch), strong specificity toward Cry1Ac-positive sequences, and reproducible classification accuracies exceeding 90%. By eliminating enzymatic amplification steps, the proposed platform significantly reduces assay time, operational complexity, and instrumentation requirements, making it suitable for rapid on-site GMO screening. Full article
(This article belongs to the Special Issue Advanced Biosensors Based on Molecular Recognition)
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30 pages, 13680 KB  
Article
Multi-Dimensional Detection Capability Analysis of Surface and Surface-to-Tunnel Transient Electromagnetic Methods Based on the Spectral Element Method
by Danyu Li, Xin Huang, Xiaoyue Cao, Liangjun Yan, Zhangqian Chen and Qingpu Han
Appl. Sci. 2026, 16(3), 1560; https://doi.org/10.3390/app16031560 - 4 Feb 2026
Viewed by 274
Abstract
The transient electromagnetic (TEM) method is a key detection and monitoring technology for safe coal-mine production. Surface TEM depth penetration is limited by real geological conditions and transmitter–receiver hardware performance. Compared with the surface TEM method, the tunnel TEM method can enhance the [...] Read more.
The transient electromagnetic (TEM) method is a key detection and monitoring technology for safe coal-mine production. Surface TEM depth penetration is limited by real geological conditions and transmitter–receiver hardware performance. Compared with the surface TEM method, the tunnel TEM method can enhance the depth of exploration to some extent, but it is constrained by the limited working space of the roadway, which makes it difficult to perform the area-wide and multi-line data acquisition, and thus the lateral detection resolution is directly compromised. Consequently, either surface or tunnel TEM alone suffers inherent limitations. The multidimensional surface and surface-to-tunnel TEM method employs a single large-loop transmitter and records electromagnetic (EM) signals both on the surface and in the tunnel, enabling joint data interpretation. The joint TEM observation method effectively addresses the limitations by using a single observation mode, with the goal of achieving high-precision detection. To investigate the detection capabilities of the joint surface and surface-to-tunnel TEM method, we propose a three-dimensional (3D) joint surface and surface-to-tunnel TEM forward modeling method based on the spectral element method (SEM). The SEM, using high-order vector basis functions, enables high-precision modeling of TEM responses with complex geo-electric earth models. The accuracy of the SEM is validated through comparisons with one-dimensional (1D) TEM semi-analytical solutions. To further reveal TEM response characteristics and multi-dimensional resolution under joint surface and tunnel detection modes, we construct several typical 3D geo-electric earth models and apply the SEM algorithm to simulate the TEM responses. We systematically analyze the horizontal and vertical resolution of 3D earth model targets at different decay times. The numerical results demonstrate that surface multi-line TEM surveying can accurately delineate the lateral extent of the target body, while vertical in-tunnel measurements are crucial for identifying the top and bottom interfaces of geological targets adjacent to the tunnel. Finally, the theoretical modeling results demonstrate that compared to individual TEM methods, the multi-dimensional joint surface and tunnel TEM observation yields superior target spatial information and markedly improves TEM detection efficacy under complex conditions. The 3D TEM forward modeling based on the SEM provides the theoretical foundation for subsequent 3D inversion and interpretation of surface-to-surface and surface-to-tunnel joint TEM data. Full article
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21 pages, 1400 KB  
Article
Frictional Contact of Functionally Graded Piezoelectric Materials with Arbitrarily Varying Properties
by Xiuli Liu, Kaiwen Xiao, Changyao Zhang, Xinyu Zhou, Lingfeng Gao and Jing Liu
Mathematics 2026, 14(3), 450; https://doi.org/10.3390/math14030450 - 27 Jan 2026
Viewed by 310
Abstract
This study investigates the two-dimensional (2D) steady-state frictional contact behavior of functionally graded piezoelectric material (FGPM) coatings under a high-speed rigid cylindrical punch. An electromechanical coupled contact model considering inertial effects is established, while a layered model is employed to simulate arbitrarily varying [...] Read more.
This study investigates the two-dimensional (2D) steady-state frictional contact behavior of functionally graded piezoelectric material (FGPM) coatings under a high-speed rigid cylindrical punch. An electromechanical coupled contact model considering inertial effects is established, while a layered model is employed to simulate arbitrarily varying material parameters. Based on piezoelectric elasticity theory, the steady-state governing equations for the coupled system are derived. By utilizing the transfer matrix method and the Fourier integral transform, the boundary value problem is converted into a system of coupled Cauchy singular integral equations of the first and second kinds in the frequency domain. These equations are solved semi-analytically, using the least squares method combined with an iterative algorithm. Taking a power-law gradient distribution as a case study, the effects of the gradient index, relative sliding speed, and friction coefficient on the contact pressure, in-plane stress, and electric displacement are systematically analyzed. Furthermore, the contact responses of FGPM coatings with power-law, exponential, and sinusoidal gradient profiles are compared. The findings provide a theoretical foundation for the optimal design of FGPM coatings and for enhancing their operational reliability under high-speed service conditions. Full article
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23 pages, 5216 KB  
Article
Improvement of the Semi-Analytical Algorithm Integrating Ultraviolet Band and Deep Learning for Inverting the Absorption Coefficient of Chromophoric Dissolved Organic Matter in the Ocean
by Yongchao Wang, Quanbo Xin, Xiaodao Wei, Luoning Xu, Jinqiang Bi, Kexin Bao and Qingjun Song
Remote Sens. 2026, 18(2), 207; https://doi.org/10.3390/rs18020207 - 8 Jan 2026
Viewed by 501
Abstract
As an important component of waters constituent that affects ocean color and the underwater ecological environment, the accurate assessment of Chromophoric Dissolved Organic Matter (CDOM) is crucial for observing the continuous changes in the marine ecosystem. However, remote sensing estimation of CDOM remains [...] Read more.
As an important component of waters constituent that affects ocean color and the underwater ecological environment, the accurate assessment of Chromophoric Dissolved Organic Matter (CDOM) is crucial for observing the continuous changes in the marine ecosystem. However, remote sensing estimation of CDOM remains challenging for both coastal and oceanic waters due to its weak optical signals and complex optical conditions. Therefore, the development of efficient, practical, and robust models for estimating the CDOM absorption coefficient in both coastal and oceanic waters remains an active research focus. This study presents a novel algorithm (denoted as DQAAG) that incorporates ultraviolet bands into the inversion model. The design leverages the distinct spectral absorption characteristics of phytoplankton versus detrital particles in the ultraviolet (UV) region, enabling improved discrimination of water color parameters. Furthermore, the algorithm replaces empirical formulas commonly used in semi-analytical approaches with an artificial intelligence model (deep learning) to achieve enhanced inversion accuracy. Using IOCCG hyperspectral simulation data and NOMAD dataset to evaluates Shanmugam (2011) (S2011), Aurin et al. (2018) (A2018), Zhu et al. (2011) (QAA-CDOM), DQAAG, the results indicate that the ag(443) derived from the DQAAG exhibit good agreement with the validation data, with root mean square deviation (RMSD) < 0.3 m−1, mean absolute relative difference (MARD) < 0.30, mean bias (bias) < 0.028 m−1, coefficient of determination (R2) > 0.78. The DQAAG algorithm was applied to SeaWiFS remote sensing data, and validation was performed through match-up analysis with the NOMAD dataset. The results show the RMSD = 0.14 m−1, MARD = 0.39, and R2 = 0.62. Through a sensitivity analysis of the algorithm, the study reveals that Rrs(670) and Rrs(380) exhibit more significant characteristics. These results demonstrate that UV bands play a crucial role in enhancing the retrieval accuracy of ocean color parameters. In addition, DQAAG, which integrates semi-analytical algorithms with artificial intelligence, presents an encouraging approach for processing ocean color imagery to retrieve ag(443). Full article
(This article belongs to the Special Issue Artificial Intelligence in Hyperspectral Remote Sensing Data Analysis)
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16 pages, 766 KB  
Article
Application of Gas Chromatographic Retention Indices to GC and GC–MS Identification with Variable Limits for Deviations Between Their Experimental and Reference Values
by Igor G. Zenkevich
Molecules 2025, 30(24), 4706; https://doi.org/10.3390/molecules30244706 - 9 Dec 2025
Viewed by 850
Abstract
The potential of a new algorithm for comparing experimental and reference values of gas chromatographic retention indices (RIs) is discussed. This algorithm is designed to minimize significant elements of uncertainty typical of numerous contemporary recommendations, primarily, the fixed limiting values of permissible deviations [...] Read more.
The potential of a new algorithm for comparing experimental and reference values of gas chromatographic retention indices (RIs) is discussed. This algorithm is designed to minimize significant elements of uncertainty typical of numerous contemporary recommendations, primarily, the fixed limiting values of permissible deviations between experimental and reference RI-values, ΔRI = (RIref − RIexp). The algorithm proposed implies the calculation of deviations, ΔRI, for the most reliably identified constituents of multicomponent mixtures in different parts of chromatograms with known reference RI values, followed by calculation of coefficients of regression equations ΔRI = (RIref − RIexp) = aRIexp + b for both of the reduced sets of analytes. This equation allows for the recalculation of experimentally determined RIs into corrected values RIcorr = RIexp + ΔRI, which means replacing the fixed “global” limits with data-dependent adaptive thresholds for different constituents of multicomponent samples. Such an algorithm makes it possible to use reference RI values for semi-standard nonpolar polydimethylsiloxane phases (with 5% phenyl groups and others) for the comparison with data determined with standard nonpolar polydimethylsiloxanes and vice versa, as well as to minimize the influence of possible erroneous reference RI data. It is applicable both to statistically processed reference data and to results of single measurements. Both of these kinds of reference data are known and presented in contemporary RI databases, e.g., in the NIST RI database. Full article
(This article belongs to the Section Analytical Chemistry)
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19 pages, 21004 KB  
Article
The Symmetry-Preserving Rosenbrock Approach: Application to Solve the Chaotic Lorenz System
by Lakhlifa Sadek and Ibtisam Aldawish
Symmetry 2025, 17(11), 1844; https://doi.org/10.3390/sym17111844 - 3 Nov 2025
Cited by 1 | Viewed by 555
Abstract
This extensive study introduces the Rosenbrock method (RosM) for numerically integrating the chaotic Lorenz system, with a focus on its ability to preserve the system’s intrinsic dynamical and structural symmetries. The Lorenz system exhibits significant symmetry, most notably an inversion symmetry [...] Read more.
This extensive study introduces the Rosenbrock method (RosM) for numerically integrating the chaotic Lorenz system, with a focus on its ability to preserve the system’s intrinsic dynamical and structural symmetries. The Lorenz system exhibits significant symmetry, most notably an inversion symmetry (x,y,z)(x,y,z), which is a fundamental feature of its chaotic attractor. We lay forth the algorithm and, after systematic comparisons to explicit Runge–Kutta higher-order schemes and semi-analytically obtained solutions, show that the second-order Rosenbrock method performs with excellent accuracy and stability. Crucially, we demonstrate that RosM reliably preserves the system’s symmetry over long-term integration, a property where some explicit methods can exhibit subtle drift. We give a formal error characterization, assess the computational efficiency, and verify the method via bifurcation analysis to support that RosM is a robust and symmetry-aware tool for simulating chaotic systems. Full article
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23 pages, 338 KB  
Review
Remote Sensing, GIS, and Machine Learning in Water Resources Management for Arid Agricultural Regions: A Review
by Anas B. Rabie, Mohamed Elhag and Ali Subyani
Water 2025, 17(21), 3125; https://doi.org/10.3390/w17213125 - 31 Oct 2025
Cited by 5 | Viewed by 4726
Abstract
Efficient water resource management in arid and semi-arid regions is a critical challenge due to persistent scarcity, climate change, and unsustainable agricultural practices. This review synthesizes recent advances in applying remote sensing (RS), geographic information systems (GIS), and machine learning (ML) to monitor, [...] Read more.
Efficient water resource management in arid and semi-arid regions is a critical challenge due to persistent scarcity, climate change, and unsustainable agricultural practices. This review synthesizes recent advances in applying remote sensing (RS), geographic information systems (GIS), and machine learning (ML) to monitor, analyze, and optimize water use in vulnerable agricultural landscapes. RS is evaluated for its capacity to quantify soil moisture, evapotranspiration, vegetation dynamics, and surface water extent. GIS applications are reviewed for hydrological modeling, watershed analysis, irrigation zoning, and multi-criteria decision-making. ML algorithms, including supervised, unsupervised, and deep learning approaches, are assessed for forecasting, classification, and hybrid integration with RS and GIS. Case studies from Central Asia, North Africa, the Middle East, and the United States illustrate successful implementations across various applications. The review also applies the DPSIR (Driving Force–Pressure–State–Impact–Response) framework to connect geospatial analytics with water policy, stakeholder engagement, and resilience planning. Key gaps include data scarcity, limited model interpretability, and equity challenges in tool access. Future directions emphasize explainable AI, cloud-based platforms, real-time modeling, and participatory approaches. By integrating RS, GIS, and ML, this review demonstrates pathways for more transparent, precise, and inclusive water governance in arid agricultural regions. Full article
40 pages, 457 KB  
Article
Large-Number Optimization: Exact-Arithmetic Mathematical Programming with Integers and Fractions Beyond Any Bit Limits
by Josef Kallrath
Mathematics 2025, 13(19), 3190; https://doi.org/10.3390/math13193190 - 5 Oct 2025
Viewed by 1193
Abstract
Mathematical optimization, in both continuous and discrete forms, is well established and widely applied. This work addresses a gap in the literature by focusing on large-number optimization, where integers or fractions with hundreds of digits occur in decision variables, objective functions, or constraints. [...] Read more.
Mathematical optimization, in both continuous and discrete forms, is well established and widely applied. This work addresses a gap in the literature by focusing on large-number optimization, where integers or fractions with hundreds of digits occur in decision variables, objective functions, or constraints. Such problems challenge standard optimization tools, particularly when exact solutions are required. The suitability of computer algebra systems and high-precision arithmetic software for large-number optimization problems is discussed. Our first contribution is the development of Python implementations of an exact Simplex algorithm and a Branch-and-Bound algorithm for integer linear programming, capable of handling arbitrarily large integers. To test these implementations for correctness, analytic optimal solutions for nine specifically constructed linear, integer linear, and quadratic mixed-integer programming problems are derived. These examples are used to test and verify the developed software and can also serve as benchmarks for future research in large-number optimization. The second contribution concerns constructing partially increasing subsequences of the Collatz sequence. Motivated by this example, we quickly encountered the limits of commercial mixed-integer solvers and instead solved Diophantine equations or applied modular arithmetic techniques to obtain partial Collatz sequences. For any given number J, we obtain a sequence that begins at 2J1 and repeats J times the pattern ud: multiply by 3xj+1 and then divide by 2. Further partially decreasing sequences are designed, which follow the pattern of multiplying by 3xj+1 and then dividing by 2m. The most general J-times increasing patterns (ududd, udududd, …, ududududddd) are constructed using analytic and semi-analytic methods that exploit modular arithmetic in combination with optimization techniques. Full article
(This article belongs to the Special Issue Innovations in Optimization and Operations Research)
23 pages, 4535 KB  
Article
Effective Elastic Moduli at Reservoir Scale: A Case Study of the Soultz-sous-Forêts Fractured Reservoir
by Dariush Javani, Jean Schmittbuhl and François H. Cornet
Geosciences 2025, 15(10), 371; https://doi.org/10.3390/geosciences15100371 - 24 Sep 2025
Cited by 1 | Viewed by 867
Abstract
The presence of discontinuities in fractured reservoirs, their mechanical and physical characteristics, and fluid flow through them are important factors influencing their effective large-scale properties. In this paper, the variation of elastic moduli in a block measuring 100 × 100 × 100 m [...] Read more.
The presence of discontinuities in fractured reservoirs, their mechanical and physical characteristics, and fluid flow through them are important factors influencing their effective large-scale properties. In this paper, the variation of elastic moduli in a block measuring 100 × 100 × 100 m3 that hosts a discrete fracture network (DFN) is evaluated using the discrete element method (DEM). Fractures are characterised by (1) constant, (2) interlocked, and (3) mismatched stiffness properties. First, three uniaxial verification tests were performed on a block (1 × 1 × 2 m3) containing a circular finite fracture (diameter = 0.5 m) to validate the developed numerical algorithm that implements the three fracture stiffnesses mentioned above. The validated algorithms were generalised to fractures in a DFN embedded in a 100 × 100 × 100 m3 rock block that reproduces in situ conditions at various depths (4.7 km, 2.3 km, and 0.5 km) of the Soultz-sous-Forêts geothermal site. The effective elastic moduli of this large-scale rock mass were then numerically evaluated through a triaxial loading scenario by comparing to the numerically evaluated stress field using the DFN, with the stress field computed using an effective homogeneous elastic block. Based on the results obtained, we evaluate the influence of fracture interaction and stress perturbation around fractures on the effective elastic moduli and subsequently on the large-scale P-wave velocity. The numerical results differ from the elastic moduli of the rock matrix at higher fracture densities, unlike the other methods. Additionally, the effect of nonlinear fracture stiffness is reduced by increasing the depth or stress level in both the numerical and semi-analytical methods. Full article
(This article belongs to the Section Geomechanics)
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20 pages, 11493 KB  
Article
Evaluation of Numerical Methods for Dispersion Curve Estimation in Viscoelastic Plates
by Jabid E. Quiroga, Octavio A. González-Estrada and Miguel Díaz-Rodríguez
Eng 2025, 6(9), 240; https://doi.org/10.3390/eng6090240 - 11 Sep 2025
Cited by 1 | Viewed by 1856
Abstract
This study aims to evaluate the effectiveness of five analytical and semi-analytical methods for estimating Lamb wave dispersion in viscoelastic plates—the Rayleigh–Lamb solution, the Global Matrix Method (GMM), the Semi-Analytical Finite Element (SAFE) method, the Scaled Boundary Finite Element Method (SBFEM), and the [...] Read more.
This study aims to evaluate the effectiveness of five analytical and semi-analytical methods for estimating Lamb wave dispersion in viscoelastic plates—the Rayleigh–Lamb solution, the Global Matrix Method (GMM), the Semi-Analytical Finite Element (SAFE) method, the Scaled Boundary Finite Element Method (SBFEM), and the Legendre Polynomial Method (LPM). The Rayleigh–Lamb equations are solved using an optimized Newton–Raphson algorithm, enhancing computational efficiency while maintaining comparable accuracy. The SAFE method exhibited a remarkable balance between computational efficiency and physical accuracy, outperforming SBFEM at high frequencies. For epoxy and high-performance polyethylene (HPPE) plates, the SAFE method and the LPM significantly outperform the GMM in relation to computational efficiency, with errors below 1% for fundamental symmetric and antisymmetric modes across the tested frequency range of 0 to 100 kHz. In addition, the ability of the SAFE method to accurately predict both phase velocity and attenuation in viscous media supports their use in guided-wave-based structural health monitoring applications. Among the investigated approaches, the SAFE method emerges as the most robust and accurate for viscoelastic plates, while the SBFEM and LPM show limitations at higher frequencies. This study provides a quantitative and methodological foundation for selecting and implementing numerical methods for guided wave analysis, emphasizing the dual necessity of physical fidelity and numerical stability. Full article
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18 pages, 879 KB  
Systematic Review
Machine Learning in Myasthenia Gravis: A Systematic Review of Prognostic Models and AI-Assisted Clinical Assessments
by Chen-Chih Chung, I-Chieh Wu, Oluwaseun Adebayo Bamodu, Chien-Tai Hong and Hou-Chang Chiu
Diagnostics 2025, 15(16), 2044; https://doi.org/10.3390/diagnostics15162044 - 14 Aug 2025
Cited by 3 | Viewed by 2575
Abstract
Background: Myasthenia gravis (MG), a chronic autoimmune disorder with variable disease trajectories, presents considerable challenges for clinical stratification and acute care management. This systematic review evaluated machine learning models developed for prognostic assessment in patients with MG. Methods: Following PRISMA guidelines, [...] Read more.
Background: Myasthenia gravis (MG), a chronic autoimmune disorder with variable disease trajectories, presents considerable challenges for clinical stratification and acute care management. This systematic review evaluated machine learning models developed for prognostic assessment in patients with MG. Methods: Following PRISMA guidelines, we systematically searched PubMed, Embase, and Scopus for relevant articles published from January 2010 to May 2025. Studies using machine learning techniques to predict MG-related outcomes based on structured or semi-structured clinical variables were included. We extracted data on model targets, algorithmic strategies, input features, validation design, performance metrics, and interpretability methods. The risk of bias was assessed using the Prediction Model Risk of Bias Assessment Tool. Results: Eleven studies were included, targeting ICU admission (n = 2), myasthenic crisis (n = 1), treatment response (n = 2), prolonged mechanical ventilation (n = 1), hospitalization duration (n = 1), symptom subtype clustering (n = 1), and artificial intelligence (AI)-assisted examination scoring (n = 3). Commonly used algorithms included extreme gradient boosting, random forests, decision trees, multivariate adaptive regression splines, and logistic regression. Reported AUC values ranged from 0.765 to 0.944. Only two studies employed external validation using independent cohorts; others relied on internal cross-validation or repeated holdout. Of the seven prognostic modeling studies, four were rated as having high risk of bias, primarily due to participant selection, predictor handling, and analytical design issues. The remaining four studies focused on unsupervised symptom clustering or AI-assisted examination scoring without predictive modeling components. Conclusions: Despite promising performance metrics, constraints in generalizability, validation rigor, and measurement consistency limited their clinical application. Future research should prioritize prospective multicenter studies, dynamic data sharing strategies, standardized outcome definitions, and real-time clinical workflow integration to advance machine learning-based prognostic tools for MG and support improved patient care in acute settings. Full article
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31 pages, 5037 KB  
Article
Evaluation and Improvement of Ocean Color Algorithms for Chlorophyll-a and Diffuse Attenuation Coefficients in the Arctic Shelf
by Yubin Yao, Tao Li, Qing Xu, Xiaogang Xing, Xingyuan Zhu and Yubao Qiu
Remote Sens. 2025, 17(15), 2606; https://doi.org/10.3390/rs17152606 - 27 Jul 2025
Cited by 1 | Viewed by 1585
Abstract
Arctic shelf waters exhibit high optical variability due to terrestrial inputs and elevated colored dissolved organic matter (CDOM) concentrations, posing significant challenges for the accurate retrieval of chlorophyll-a (Chl-a) and downwelling diffuse attenuation coefficients (Κd(λ) [...] Read more.
Arctic shelf waters exhibit high optical variability due to terrestrial inputs and elevated colored dissolved organic matter (CDOM) concentrations, posing significant challenges for the accurate retrieval of chlorophyll-a (Chl-a) and downwelling diffuse attenuation coefficients (Κd(λ)). These retrieval biases contribute to substantial uncertainties in estimates of primary productivity and upper-ocean heat flux in the Arctic Ocean. However, the performance and constraints of existing ocean color algorithms in Arctic shelf environments remain insufficiently characterized, particularly under seasonally variable and optically complex conditions. In this study, we present a systematic multi-year evaluation of commonly used empirical and semi-analytical ocean color algorithms across the western Arctic shelf, based on seven expeditions and 240 in situ observation stations. Building on these evaluations, regionally optimized retrieval schemes were developed to enhance algorithm performance under Arctic-specific bio-optical conditions. The proposed OCx-AS series for Chl-a and Κd-DAS models for Κd(λ) significantly reduce retrieval errors, achieving RMSE improvements of over 50% relative to global standard algorithms. Additionally, we introduce QAA-LS, a modified semi-analytical model specifically adapted for the Laptev Sea, which addresses the strong absorption effects of CDOM and corrects the significant overestimation observed in previous QAA versions. Full article
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