We investigate a ferrimagnetic/ferroelectric bilayer in which a mixed-spin Heisenberg ferrimagnet is coupled to a three-state ferroelectric layer allowing for a nonpolar state. Using Monte Carlo simulations, we analyze how magnetic and electric single-ion anisotropies, together with interfacial magnetoelectric coupling, control phase transitions and hysteresis properties. We show that electric anisotropy, by tuning the population of nonpolar ferroelectric sites, strongly shifts the ferrimagnetic critical temperature, while magnetic anisotropy reciprocally affects the ferroelectric transition. Increasing the magnetoelectric coupling enhances both ordering temperatures and may induce a common transition. At fixed temperature, magnetic and electric hysteresis loops evolve from square to slim and nearly reversible shapes as anisotropies are varied. These results highlight the relevance of three-state ferroelectricity for describing polarization suppression and tunable magnetoelectric response in hybrid bilayers.
Dimensional reduction is a generic consequence of dissipation in nonlinear evolution equations, often leading to attractor collapse and the loss of dynamical richness. To counteract this, we introduce a geometric framework for Covariant Multi-Scale Negative Coupling Systems (C-MNCS), formulated intrinsically on smooth Riemannian manifolds for a broad class of semilinear dissipative PDEs. The proposed coupling redistributes energy across dynamically separated spectral bands, inducing a scale-balanced feedback that prevents finite-dimensional degeneration. We establish the short-time well-posedness of the coupled state-metric evolution system in Sobolev spaces and derive a priori estimates for phase-space contraction rates. Furthermore, under a global boundedness hypothesis, we prove that the global attractor possesses a strictly finite Hausdorff and Kaplan-Yorke dimension. To bridge abstract topological bounds with physical realizability, we isolate the core Adaptive Spectral Negative Coupling (ASNC) mechanism for numerical validation. High-resolution experiments, utilizing a fully coupled ETDRK4 scheme and continuous QR-based Lyapunov exponent computation on a conformally flat 2D dynamic scalar manifold, corroborate the theoretical predictions. These computations explicitly demonstrate the stabilization of high-dimensional attractors against severe macroscopic dissipation. This geometrically consistent mechanism offers a new paradigm for maintaining structural complexity and multiscale control in infinite-dimensional dynamical systems.
Gabriela Macedo Miranda, Fernanda Castells Vidaller Laurino, Marcos Saito de Paula
et al.
Landslides constitute a recurrent natural hazard globally, severely impacting socio-economic and environmental systems. In Brazil, and particularly in the road infrastructure of Rio Grande do Sul, this vulnerability was dramatically evidenced by the extreme events of 2024. This study addresses the instability of 43 rock slopes along the BR-470 highway in the Serra das Antas region (between Bento Gonçalves and Veranópolis), a critical area with a history of rainfall-induced landslides structurally controlled by brittle discontinuities (columnar and sub-horizontal joints). The core objective was to perform a detailed geological-structural mapping of the Serra Geral Formation basaltic rock masses to diagnose instability patterns and define optimized intervention protocols. The methodology employed an integrated approach, combining detailed field geological-geotechnical mapping with kinematic and geomechanical analyses (limit equilibrium via Mohr-Coulomb and Hoek-Brown criteria). A geological-geotechnical compartmentalization of the rock masses was developed to reflect the complex structural heterogeneity, and the rock mass quality was assessed and classified using the GSI and RMR indices. Structural and kinematic analysis confirmed the prevalence of instabilities conditioned by these discontinuities, resulting in rockfall as the dominant failure mechanism (93% of cases), frequently associated with wedge failure (61%). The proposed stabilization solutions — including high-tensile steel mesh with anchored bolts and dynamic barriers — replace the traditional homogeneous treatment with a compartmentalized approach. It is concluded that compartmentalization constitutes an effective model, allowing technical and economic adjustments of the interventions to the specific geomechanical conditions of each segment, thereby increasing the reliability of the results and enhancing road safety.
J. C. Acosta Navarro, A. Aranyossy, P. De Luca
et al.
<p>Seamless climate predictions integrate forecasts across various timescales to provide actionable information in sectors such as agriculture, energy, and public health. While significant progress has been made, there is still a gap in the continuous provision of operational forecasts, particularly from seasonal to multi-annual timescales. We demonstrate that filling this gap is possible using an established climate model analog method to constrain variability in CMIP6 climate simulations. The analog method yields predictive skill for surface air temperature forecasts across timescales, ranging from seasons to several years. On average, the analog-based surface air temperature predictions provide added value over the unconstrained CMIP6 ensemble, especially on seasonal to annual timescales. Similar to operational climate prediction systems, Standardized Precipitation Index forecasts are less skillful than surface air temperature forecasts but still better than the CMIP6 unconstrained simulations. The analog-based seamless prediction system shows very similar patterns of skill compared to state-of-the art initialized climate prediction systems and has competitive skill on annual and biennial forecast ranges. While the current prediction systems provide only 1–2 initializations per year, the analog-based system can easily provide predictions with monthly initializations, delivering seamless climate information throughout the year currently not available from traditional seasonal or decadal prediction systems. Furthermore, due to analog-based predictions being computationally inexpensive, we argue that these methods are a valuable and viable complement to existing operational prediction systems.</p>
<p>Effective climate change mitigation necessitates swift societal transformations. Positive social tipping processes, where small triggers initiate qualitative systemic shifts, are potential key mechanisms towards instigating the desired emissions mitigation. A necessary foundation for societal tipping processes is the creation of enabling conditions. Here, we assess future sea level rise estimates and social survey data within the framework of a network-based threshold model to exemplify the enabling conditions for tipping processes. We find that in many countries, the level of climate change concern is already sufficient, suggesting the enabling conditions and opportunities for social activation already exist. Further, drawing upon the interrelation between climate change concern and anticipation of future sea level rise, we report three qualitative classes of tipping potential that are regionally clustered, with the greatest potential for tipping in western Pacific Rim and East Asian countries. These findings propose a transformative pathway where climate change concern increases the social tipping potential, while extended anticipation time horizons can trigger the system towards an alternative trajectory of larger social activation for climate change mitigation.</p>
Estimating accurate camera poses, 3D scene geometry, and object motion from in-the-wild videos is a long-standing challenge for classical structure from motion pipelines due to the presence of dynamic objects. Recent learning-based methods attempt to overcome this challenge by training motion estimators to filter dynamic objects and focus on the static background. However, their performance is largely limited by the availability of large-scale motion segmentation datasets, resulting in inaccurate segmentation and, therefore, inferior structural 3D understanding. In this work, we introduce the Dynamic Prior (\ourmodel) to robustly identify dynamic objects without task-specific training, leveraging the powerful reasoning capabilities of Vision-Language Models (VLMs) and the fine-grained spatial segmentation capacity of SAM2. \ourmodel can be seamlessly integrated into state-of-the-art pipelines for camera pose optimization, depth reconstruction, and 4D trajectory estimation. Extensive experiments on both synthetic and real-world videos demonstrate that \ourmodel not only achieves state-of-the-art performance on motion segmentation, but also significantly improves accuracy and robustness for structural 3D understanding.
We take a new perspective on identification in structural dynamic models: rather than imposing restrictions, we optimize an objective. This provides new theoretical insights into traditional Cholesky identification. A correlation-maximizing objective yields an Order- and Scale-Invariant Identification Scheme (OASIS) that selects the orthogonal rotation that best aligns structural shocks with their reduced-form innovations. We revisit a large number of SVAR studies and find, across 22 published SVARs, that the correlations between structural and reduced-form shocks are generally high.
Large language models exhibit intelligence without genuine epistemic understanding, exposing a key gap: the absence of epistemic architecture. This paper introduces the Structured Cognitive Loop (SCL) as an executable epistemological framework for emergent intelligence. Unlike traditional AI research asking "what is intelligence?" (ontological), SCL asks "under what conditions does cognition emerge?" (epistemological). Grounded in philosophy of mind and cognitive phenomenology, SCL bridges conceptual philosophy and implementable cognition. Drawing on process philosophy, enactive cognition, and extended mind theory, we define intelligence not as a property but as a performed process -- a continuous loop of judgment, memory, control, action, and regulation. SCL makes three contributions. First, it operationalizes philosophical insights into computationally interpretable structures, enabling "executable epistemology" -- philosophy as structural experiment. Second, it shows that functional separation within cognitive architecture yields more coherent and interpretable behavior than monolithic prompt based systems, supported by agent evaluations. Third, it redefines intelligence: not representational accuracy but the capacity to reconstruct its own epistemic state through intentional understanding. This framework impacts philosophy of mind, epistemology, and AI. For philosophy, it allows theories of cognition to be enacted and tested. For AI, it grounds behavior in epistemic structure rather than statistical regularity. For epistemology, it frames knowledge not as truth possession but as continuous reconstruction within a phenomenologically coherent loop. We situate SCL within debates on cognitive phenomenology, emergence, normativity, and intentionality, arguing that real progress requires not larger models but architectures that realize cognitive principles structurally.
Alessandro Lucchetti, Francesco Cadini, Marco Giglio
et al.
Graph Neural Networks (GNNs) have recently been explored as surrogate models for numerical simulations. While their applications in computational fluid dynamics have been investigated, little attention has been given to structural problems, especially for dynamic cases. To address this gap, we introduce the Graph Network-based Structural Simulator (GNSS), a GNN framework for surrogate modeling of dynamic structural problems. GNSS follows the encode-process-decode paradigm typical of GNN-based machine learning models, and its design makes it particularly suited for dynamic simulations thanks to three key features: (i) expressing node kinematics in node-fixed local frames, which avoids catastrophic cancellation in finite-difference velocities; (ii) employing a sign-aware regression loss, which reduces phase errors in long rollouts; and (iii) using a wavelength-informed connectivity radius, which optimizes graph construction. We evaluate GNSS on a case study involving a beam excited by a 50kHz Hanning-modulated pulse. The results show that GNSS accurately reproduces the physics of the problem over hundreds of timesteps and generalizes to unseen loading conditions, where existing GNNs fail to converge or deliver meaningful predictions. Compared with explicit finite element baselines, GNSS achieves substantial inference speedups while preserving spatial and temporal fidelity. These findings demonstrate that locality-preserving GNNs with physics-consistent update rules are a competitive alternative for dynamic, wave-dominated structural simulations.
The influence of rolling stock loading on a twenty-three-story frame building located near the movement of railway trains in an urban area was investigated. Mathematical modeling of the dynamic behavior of multi-story buildings subjected to rolling stock loading was performed using a two-stage numerical method. In the first stage, a finite element model of the multilayer soil foundation along with the ballast prism was created in the NASTRAN software complex, represented as a planar elastoplastic half-space with a length of 200 m and a depth of 30 m. A real geological cross-section consisting of five layers with different physical characteristics was used. The rolling stock load is represented as a vertical periodic excitation, concentrated at the center of mass of the system consisting of the bogie frame, the wheelsets of a freight wagon, and the ballast prism. Modal analysis of the soil foundation and the ballast prism was performed using the Lanczos method. The influence of rolling stock loading on the dynamic behavior of the soil foundation was investigated using the fourth-order Runge-Kutta method. Horizontal and vertical displacements and accelerations of the soil were obtained at various distances and depths of the foundation model from the railway track axis. In the second stage, a 3D model of the monolithic frame building was created in the SCAD software complex. Modal analysis of the structure was performed using the subspace iteration method. Two calculation options for the multi-story building were considered. The first calculation was performed for the action of design load combinations: permanent, sustained, and short-term (snow, wind load). In the second calculation option, the stress-strain state of the building was investigated using the spectral method under the action of design loads and kinematic soil excitation, applied along the height of the building's foundation in the form of acceleration vectors. The accelerations were considered in two directions and added to the design combinations along the two directions of wind load influence. A comparison of the two calculation options was performed to check the reliability and structural safety of the building.
Tectonically, the southern Lower Yangtze region lies between the Dabie Orogenic Belt and Jiangnan Orogenic Belt. A series of Meso-Cenozoic basins developed in this area serve as a crucial window for revealing the basin structure and tectonic-sedimentary evolution in Eastern China. While geologically significant, the current understanding of these basins’ fundamental geological characteristics remains constrained. In particular, the basin’s structural framework and formation-evolution processes lack constraints from integrated geophysical data. This study conducted a systematic investigation into the structural characteristics, sedimentary filling patterns, and formation-evolution processes of three representative Meso-Cenozoic basins in the southern Yangtze region using deep seismic reflection and magnetotelluric sounding methods. The results indicate that two sets of thrust faults with opposite dips have developed within the crust of the study area, with the convergence center of the opposing thrusts located in the Huaining Basin, which controls the distribution of regional Jurassic strata. The central Huaining volcanic basin is associated with magma upwelling, with its main sedimentary filling occurring in the Early Cretaceous. In contrast, the Qianshan and Wangjiang basins are half-graben faulted basins formed under extensional stress. These faulted basins entered an active phase since the Late Cretaceous, marked by discontinuous sedimentation of the Upper Cretaceous to Paleogene strata. The boundary fault of the Qianshan Basin is considered the eastern branch fault of the Tan-Lu Fault, characterized by an evolutionary history of early strike-slipping followed by late-stage extension. Moreover, the boundary fault of the Wangjiang Basin exhibits a negative inversion structure, undergoing a dynamic transition from an early compressional thrusting phase to a subsequent extensional regime. The southern Lower Yangtze region experienced at least two compressional tectonic events during the Paleogene, which induced differential uplift and erosion of the basins. In light of the above analysis, a structural and sedimentary evolution model for the Meso-Cenozoic basins in the southern Lower Yangtze region has been constructed. The research findings provide important support for regional oil and gas exploration practices and further deepening the understanding of tectonic evolution processes in the Lower Yangtze region.
ABSTRACT Combined with the validations of the nonlinear material models, this study addresses the nonlinear dynamic response, damage mechanisms and failure modes of reinforced concrete frame structures under rockfall impacts, utilizing explicit dynamic analysis software for detailed model of structures. The findings indicate that the peak impact force is primarily influenced by the impact velocity and subsequently by the impact mass, while the impact location exerts the least influence; A linear relationship is observed between the maximum impact force and rockfall diameter, whereas a nonlinear association exists with rockfall velocity; Predominant failure modes include global and local failures, with damage and failure predominantly concentrated on the impacted columns and their surrounding components; Notably, similar damage levels were observed for corner and edge middle columns of structures under rockfall impacts; The column base, mid-column and column top primarily exhibit flexural-shear failure, flexural failure and flexural-shear failure, respectively; Given the higher rate of plastic energy absorption during mid-column impacts compared to column base and top impacts, a rockfall striking mid-column results in higher dynamic response and greater structural damage. This study can provide useful reference in design and restoration of low-rise reinforced concrete frame structures located in areas prone to frequent geological disasters.
Modern society is heavily reliant on minerals to support current lifestyles and requires continued investment in the exploration, evaluation, development, and production of mineral raw materials. Potential investors and their advisors require reliable information to support decisions on investments in minerals projects. To address these needs, international guidelines and reporting standards have been developed. The Committee for Mineral Reserves International Reporting Standards (CRIRSCO) is an international association of fifteen regional organisations from around the world, which promotes best standards in international minerals reporting. The Pan-European Reserves and Resources Reporting Committee (PERC), the European member of CRIRSCO, is an association of six Europe-based professional organisations, including the Geological Society of London (GSL). CRIRSCO-aligned reporting standards, such as the PERC Reporting Standard, are based on common principles, rules and guidance, and include sixteen common definitions of key terms. A description of the CRIRSCO International Reporting Template, which provides the basis for the development and periodic updating of individual standards such as the PERC Reporting Standard, is provided. The different elements of the 2019 version of the CRIRSCO Template are described, together with a discussion of changes and additions made in the PERC Reporting Standard 2021 which is based on it. The need for continual development and enhancement of the CRIRSCO-aligned standards to address investor concerns such as the need for information on the environmental, social and governance (ESG) aspects of mineral projects, as well as greater rigour in defining competency requirements, is discussed. Reference is also made to the United Nations Framework Classification for Resources (UNFC) and its relationship with the CRIRSCO-aligned standards, including the proposed use of the UNFC in the European Union’s Critical Raw Materials Act (CRMA) and how the two systems could be used in a complementary manner to support the needs of both governments and investors in mineral companies.
Abu Raihan Mohammad Al-Biruni, Md Masum Billah, Junji Yagisawa
In this study, the effects of the grain size and gradation of riprap, the overtopping flow depth, and the downstream slope of the embankment on the scouring and deposition characteristics at the downstream toe of the embankment were investigated. For the experiment, three different downstream slopes (1:2, 1:3, and 1:4), three different overflow depths (1, 2, and 3 cm), and three different sizes of riprap particles (<i>d</i><sub>50</sub> of 16.41 mm, 8.48 mm, and 3.39 mm, herein referred to as coarse gravel, medium gravel, and granule, respectively) were used in the laboratory. The experimental results demonstrated that the scour depth and deposition height increased with increasing energy head for each downstream slope condition. Among the three particle sizes, coarse gravel shows the lowest scour depth and the highest deposition height. For the 1:2 slope, the coarse gravel particle size was 62% and 75% less resistant to scouring than the medium gravel and granule particles, respectively. For the 1:3 slope case, this was 31% and 46%, and for the 1:4 slope case, this was 39% and 49% less than the medium gravel and granule size particles, respectively.
Camillo De Lellis, Paul Minter, Anna Skorobogatova
We study fine structural properties related to the interior regularity of $m$-dimensional area minimizing currents mod$(q)$ in arbitrary codimension. We show: (i) the set of points where at least one tangent cone is translation invariant along $m-1$ directions is locally a connected $C^{1,β}$ submanifold, and moreover such points have unique tangent cones; (ii) the remaining part of the singular set is countably $(m-2)$-rectifiable, with a unique flat tangent cone (with multiplicity) at $\mathcal{H}^{m-2}$-a.e. flat singular point. These results are consequences of fine excess decay theorems as well as almost monotonicity of a universal frequency function.
Urban scene generation has been developing rapidly recently. However, existing methods primarily focus on generating static and single-frame scenes, overlooking the inherently dynamic nature of real-world driving environments. In this work, we introduce DynamicCity, a novel 4D occupancy generation framework capable of generating large-scale, high-quality dynamic 4D scenes with semantics. DynamicCity mainly consists of two key models. 1) A VAE model for learning HexPlane as the compact 4D representation. Instead of using naive averaging operations, DynamicCity employs a novel Projection Module to effectively compress 4D features into six 2D feature maps for HexPlane construction, which significantly enhances HexPlane fitting quality (up to 12.56 mIoU gain). Furthermore, we utilize an Expansion & Squeeze Strategy to reconstruct 3D feature volumes in parallel, which improves both network training efficiency and reconstruction accuracy than naively querying each 3D point (up to 7.05 mIoU gain, 2.06x training speedup, and 70.84% memory reduction). 2) A DiT-based diffusion model for HexPlane generation. To make HexPlane feasible for DiT generation, a Padded Rollout Operation is proposed to reorganize all six feature planes of the HexPlane as a squared 2D feature map. In particular, various conditions could be introduced in the diffusion or sampling process, supporting versatile 4D generation applications, such as trajectory- and command-driven generation, inpainting, and layout-conditioned generation. Extensive experiments on the CarlaSC and Waymo datasets demonstrate that DynamicCity significantly outperforms existing state-of-the-art 4D occupancy generation methods across multiple metrics. The code and models have been released to facilitate future research.
The solution of the problem of mathematical modeling of dynamic influences on building structures is considered in general and in connection with important scientific and practical tasks. In modern conditions, special attention should be paid to the problems of taking into account dynamic influences, parameters of load-bearing structures of buildings that affect their structural reliability and safety. For many years, information about catastrophic destruction of buildings and structures has been appearing more often, which are the result not only of errors that arose during the construction of facilities, but also due to dynamic influences that arose during their operation. A buildable technical system will be used in advance with the technical parameters set, which is responsible for the control of the process of the preparation of structures, the installation of the equipment, during the operation and operation. The development will be carried out and the sporud will be constantly used to promote the development of future technologies, the development and the establishment of the future, as well as the development of dynamic developments in the future. In particular, it is important to understand the development of the engineering and geological minds of the spores, as they have known the front deformation of the non-essential axis of the runt foundations. Various methods are used for structural dynamics, such as modal analysis, response spectrum analysis, time analysis, and finite element analysis. These methods include mathematical modeling, numerical simulation, and computational methods to predict the behavior and response of a structure under dynamic load conditions. Knowing the frequency and form of the structure, it is possible to estimate the dynamic reaction of the design to the application. For the purpose of including the transfer of the world, the destruction of internal forces in the real parts of the construction. Analyses of the response to the additional assessment of the characteristics of the construction, the identification of critical areas and the re-conversion, which the project is able to meet the criteria.
Rock bursts are a natural phenomenon that are caused by high stresses and faults within the deep geological profile. The framework within deep mining excavations, comprising various rock and face supports such as cable bolts, is required to withstand rock bursts. These mechanisms are subject to static and dynamic loading conditions which possess unique challenges. This study focused on the shearing impact of static loads on cable bolts, a key structural support mechanism designed to absorb energy and investigate the impacts of bolt diameter and strength. A double shear test was modelled using the Finite Element Analysis (FEA) software ABAQUS/Explicit. A double shear test was modelled using Finite Element Modelling (FEM) by creating individual parts, assigning material and contact properties and applying a load directly on the central block. Because ABAQUS/Explicit was used, a primarily dynamic analysis tool, quasi-static loading, was applied to negate the natural time scale. A total of six bolt diameters and six bolt strengths were tested. A positive correlation was exhibited between the bolt diameter, yield strength and the maximum force and displacement.