Search Results (769)

This work presents the first complete system for automated six degrees of freedom (6DOF) satellite pose estimation from spatially resolved, ground-based, adaptive optics (AO)-corrected imagery, addressing a key challenge in Space Domain Awareness (SDA). The approach mitigates the need for human labeling by directly regressing satellite orientation and position from blurry, noisy, and deeply shadowed imagery. A multi-stage deep neural network pipeline localizes the satellite, predicts pose, and optionally applies temporal filtering. Networks are trained exclusively on fully synthetic imagery generated from a CAD model, yet generalize effectively to real data, bridging the Sim2Real domain gap. On 137 real, human-labeled test images of Seasat, the model achieved a mean rotation error of $5^{°}$ and a mean image-plane translation error of 21 cm. Slant range error was quantitatively evaluated on synthetic data due to unknown real-sensor parameters. Qualitative evaluation of additional real Seasat imagery rated 177 of 199 predicted poses as “ground truth equivalent” or “high-confidence match,” with zero catastrophic failures. The system was extended to seven degrees of freedom (7DOF) for satellites with articulating components and demonstrated on real Hubble Space Telescope (HST) imagery, achieving ${5.5}^{°}$ rotation error, 51 cm image-plane translation error, and $8^{°}$ symmetry-adjusted solar array error on a 249-frame pass with causal temporal filtering. Across 586 real test images from Seasat and HST (captured over multiple decades under diverse conditions) the system consistently performed well. Full 6DOF performance was quantified on a high-fidelity wave optics (HFWO) synthetic test set of Seasat, where the model achieved ${8.4}^{°}$ mean rotation error, 34 cm image-plane translation error, and 1.4% line-of-sight range error at $r_0=6$ cm and 1031 km range. In a limited 200-image benchmark, the model demonstrated 48% lower mean rotation error than a single human labeler while operating ∼800× faster. It required <40 h and a single A100 GPU to generate data and train. The approach was also demonstrated for ARGOS, a smaller satellite with highly symmetric geometry. An exploratory General Image-Quality Equation-based image quality metric (AO-IQ) was introduced as an empirical correlate for pose accuracy. General-purpose models like GPT-4o and Depth Anything V2 failed across most SDA tasks, but rapid gains in vision-language models warrant continued monitoring. These results establish a new operational baseline for practical, real-time satellite pose estimation from AO SDA imagery. Full article

A fail-safe topology optimization method for fiber-reinforced composite structures under dynamic loads is proposed to achieve the concurrent optimization of structural topology and fiber orientations, as well as enhance the structural redundancy subject to damage cracks of fiber-reinforced composite structures under external dynamic loads. To prevent fiber orientations from getting trapped in local optima, we employ a discrete–continuous parameterization method to convert the continuous orientation problem to a discrete subinterval selection problem and a continuous orientation optimization problem in a subinterval. To prevent structural catastrophic failure induced by damage cracks, we incorporate the fail-safe design concept by considering local damage via removing the stiffness of the composite in the predefined patch. Furthermore, to reduce the large computational burden involved in transient analysis under dynamic loads, we adopt the equivalent static loads method to transfer the dynamic loads into a set of static loads, thereby largely accelerating the optimization process while keeping the solution accuracy. The effectiveness of the method is verified by three numerical examples, showing that the equivalent static loads method-based fail-safe design of composite structures with concurrently optimized topology and fiber orientations can effectively resist the local damage induced by partial failure. Specifically, the method reduces the optimization time by around 40% while ensuring relative errors within 2% and convergence measures of fiber orientations larger than 95% in all examples, and can have up to six orders higher residual stiffness subjected to post-imposed damage patches compared to the traditional method, showing the efficiency of the proposed method. Full article

Integrated Modular Avionics (IMA) integrates safety-critical functions on shared computing and network resources, creating coupling channels through which a local fault may escalate into a catastrophic system-level scenario. This study develops a graph-based fractional-order model for cascade escalation in IMA architectures with communication delays and reconfiguration failures. The architecture is represented as a weighted directed graph of core processing modules, network switches, and remote data concentrators, where each node carries functional degradation and queue-backlog states. The proposed delayed Caputo fractional-order dynamics incorporate degradation propagation, backlog spillover, mixed-criticality priority conflict, and a state-dependent reconfiguration-failure mechanism. We establish well-posedness and positive invariance of the feasible state domain, derive a sufficient cascade threshold that separates a delay-independent, globally Mittag–Leffler stable nominal regime from a supercritical regime in which bistability and catastrophic attractors may occur, and characterize delay-induced oscillatory instability together with a memory-stabilization effect. Numerical experiments on a synthetic 22-node IMA configuration show fault absorption below the threshold, reconfiguration-contained cascades under sufficient supervisory capacity, and global escalation when reconfiguration collapses under load. The results indicate that backlog growth is an early warning signal and that maintaining the cascade threshold below unity while provisioning reconfiguration capacity above the tipping point can support safer reconfiguration-policy design in certifiable avionics. Full article

Irving Greenberg (b. 1933), among the most influential American Jewish theologians responding to the Holocaust, consistently describes his theological approach as “postmodern”—emphasising the breakdown of absolutes, fragmentation, and the failure of modern certainties. This article argues that the label is misleading. Through a reading of Greenberg’s foundational concepts—the voluntary covenant, tzelem Elokim, the assumption of power, and tikkun olam—set against the conceptual apparatus of continental postmodernism and classical American pragmatism, we will show that Greenberg’s theological method and normative conclusions align far more closely with the pragmatist tradition of Peirce, James, and Dewey. Where continental postmodernism tends toward deconstruction and the dissolution of normative claims, Greenberg’s thought exhibits characteristic pragmatist motifs: fallibilism without nihilism, pluralism without relativism, and a robust meliorism oriented toward world repair. His dictum that “pluralism is an absolutism that knows its limits” echoes William James’s pluralism rather than Derridean deconstruction, and his post-Holocaust ethic of power directly resists postmodern suspicion of agency. Reading Greenberg through the lens of American pragmatism offers a new perspective on post-Holocaust Jewish theology and clarifies how distinct intellectual traditions shape theological responses to catastrophe. Full article

In the current paper, pulmonary emphysema is hypothesized to emerge from a nonlinear breakdown of cooperation across two tightly coupled systems: the extracellular matrix (ECM) crosslink network and the cellular populations responsible for its maintenance. To formalize this concept, we construct a game-theoretic model that unifies the mechanical failure, inflammatory changes, and percolation-driven tissue collapse that are recognized features of the disease. At the ECM level, elastin and collagen crosslinks are modeled as players in an iterated Prisoner’s Dilemma, where cooperation corresponds to maintaining structural integrity, and defection corresponds to rupture under mechanical stress. At the cellular level, fibroblasts, macrophages, and neutrophils engage in a parallel strategic game in which repair reflects cooperative activity, and protease- or oxidant-producing phenotypes are indicative of defection. These parallel games are coupled through bidirectional payoff modulation, generating a dynamical system with bistability, tipping points, and runaway positive feedback. As the fraction of intact crosslinks falls below a critical percolation threshold, global network connectivity collapses and lung function drops precipitously. This framework explains the characteristic features of pulmonary emphysema, including spatial heterogeneity, abrupt acceleration, and irreversibility as emergent properties of coupled cooperation–defection dynamics, and identifies new leverage points for stabilizing cooperation and preventing catastrophic network failure in early disease. In support of this hypothesis, we present previously published studies from our laboratory involving measurements of elastin-specific desmosine crosslinks in human postmortem emphysematous lungs showing a marked increase in tissue crosslink density at the early stage of the disease, and accelerating loss of these crosslinks as airspace enlargement progresses, consistent with initial cooperation followed by defection. This conceptual framework is then applied to the poorly understood lung disease, Combined Pulmonary Fibrosis and Emphysema, to provide a potential mechanism for its pathogenesis. Full article

Fire-induced domino effects in tank farms can be catastrophic, particularly under wind conditions. However, due to multiple evolutionary stages, Computational Fluid Dynamics (CFD)-based modelling of wind-influenced, fire-induced domino effects and tank farm Time to Failure (TTF) calculation remain computationally expensive. This study addresses this gap by using Fire Dynamics Simulator (FDS) to model fire-induced domino effects in a tank farm and perform detailed tank farm TTF calculations across multiple wind speeds and primary pool fire scenarios. The FDS results showed that increasing wind speed from 0 to 8 m/s altered domino escalation, increasing incident heat flux on the downwind in-line tank by more than sevenfold (a 35% reduction in tank farm TTF). A new perturbation-based analytical formulation was then proposed for rapid determination of tank farm TTF under wind effects, without requiring complete CFD simulations of pool fire escalation. The formulation updates tank farm TTF under the no-wind baseline solution with wind-influenced perturbative correction terms. The proposed formulation agreed with the detailed CFD modelling-based calculation, with a mean relative error of 2.8% across all primary fire scenarios and wind conditions. This formulation provides a practical basis for rapid assessment of domino effects due to pool fire under wind conditions. However, it is calibrated for one specific six-tank configuration and crosswind directions and is not yet general. Full article

Background/Objectives: The advent of immune checkpoint inhibitors (ICIs) and targeted therapies has revolutionized advanced melanoma treatment but introduced unique immune-related adverse events (irAEs). Hematological irAEs (Hem-irAEs) are rare but carry disproportionately high morbidity and mortality. This review systematically synthesizes current literature to comprehensively understand the incidence, pathophysiology, clinical presentation, and management of Hem-irAEs in modern melanoma therapy. Methods: A comprehensive Web of Science literature search (January 2015 to January 2026) identified studies reporting hematological adverse events associated with melanoma immunotherapy and targeted therapies. After screening 2274 records, 130 relevant studies were included for quantitative data extraction, focusing on incidence rates and toxicity grading. Results: Hem-irAEs occur infrequently (under 4% overall incidence for ICIs) but possess staggering mortality rates between 12% and 15.5%. The most common manifestations are immune thrombocytopenia (ITP), autoimmune hemolytic anemia, and neutropenia. Combination regimens significantly amplify toxicity frequency and severity. Diagnosis requires meticulous baseline monitoring and bone marrow biopsies to differentiate peripheral destruction from central marrow failure. First-line management mandates ICI discontinuation and high-dose corticosteroids, utilizing targeted second-line immunosuppressants for refractory syndromes. Conclusions: Hem-irAEs embody a profound clinical paradox: while mild toxicities often herald a robust anti-tumor response, severe hematological events drastically increase non-cancer mortality, negating these oncological benefits. Navigating this “double-edged sword” demands a paradigm shift toward proactive risk stratification. Integrating predictive biomarkers including baseline autoantibodies, Human Leukocyte Antigens (HLA) profiling, and systemic inflammatory indices is crucial to identify vulnerable populations before treatment. Optimizing outcomes requires highly personalized vigilance to balance the life-saving efficacy of immunotherapy against the catastrophic threat of hematopoietic failure. Full article

With the rapid development of recycling and secondary utilization of end-of-life battery materials, it is crucial to clarify the impact of full-lifecycle degradation on the thermal safety limits of lithium-ion batteries. This study focuses on a 16 Ah NCM613|graphite pouch battery. First, it analyzes the evolution of capacity decay, thickness expansion, and internal resistance during cycling at room temperature (25 °C) and high temperature (45 °C). Furthermore, an adiabatic accelerated calorimeter (ARC) is employed to investigate the influence of different states of health (SOH) levels (95% and 85%) on the battery’s thermal runaway characteristics. The findings indicate that, macroscopically, batteries in all states follow similar voltage–temperature failure pathways, with mass loss rates confined to a narrow range of approximately 16%, emphasizing the low catastrophic potential of mid-nickel chemistry. However, the microscopic kinetic mechanisms exhibit significant anisotropy: although thickness and internal resistance display no apparent abrupt increase during the late stage of room temperature aging, the capacity exhibits a highly nonlinear plunge behavior. The severe internal lithium plating side reaction triggered by this phenomenon causes the self-heating onset temperature to drop rapidly from 130.0 °C in the fresh state to 79.7 °C. Concurrently, the activation energy of the exothermic side reaction, fitted using a simplified Arrhenius equation, exhibits a non-monotonic variation with aging progress. In the early stages of aging at 95% SOH, due to high temperatures promoting more significant growth of the interfacial film or moderate film formation at room temperature enhancing interfacial thermal stability, the activation energies for both aged batteries increase, and the energy barrier at high temperatures is slightly higher than at room temperature; however, during the deep aging stage at 85% SOH, due to the degradation of active material components and the emergence of lithium plating characteristics, the energy barrier significantly decreases, with high-temperature-aged batteries exhibiting a greater reduction, highlighting the cumulative negative impact of prolonged high-temperature exposure on thermal safety. The research provides a core scientific basis for establishing a battery safety early warning and dynamic health management system covering the entire lifecycle. Full article

Geomagnetically induced current (GIC) flowing through power transformers causes core saturation, leading to local hot-spot overheating, abnormal vibration, increased noise, and even irreversible transformer damage and forced outage. To prevent catastrophic GIC-induced failures, relay protection must isolate transformers in a timely and reliable manner, yet GIC has long been a critical challenge interfering with the correct operation of conventional transformer protection systems. This paper studies transformer excitation current characteristics under GIC impact, establishes a transformer model with extreme GIC injection, analyzes differential protection performance under varying GIC magnitudes, proposes a modified differential protection method, and verifies its effectiveness via simulations and experiments. Results demonstrate that GIC distorts transformer excitation current, introducing a second harmonic into differential current to trigger differential tripping blocking. The distinct second-harmonic features between magnetizing inrush and GIC injection enable reliable selective unblocking of harmonic restraint. To enable the differential protection to operate correctly under different GIC injection conditions, the operating threshold shall be adjusted according to the transformer parameters after the harmonic blocking is deactivated. The proposed strategy can potentially disable the harmonic blocker during GIC events, allowing relays to trip on demand, which is critical for ensuring transformer safety under extreme conditions. Full article

In the event of a nuclear or volcanic winter, up to two-thirds of sunlight could be blocked (abrupt sunlight reduction scenarios, ASRS), leading to a worldwide crop failure. There are some similarities between such effects and the short northern summer. This suggests the possibility of transferring successful agricultural practices validated in high latitudes to tropical regions, especially low-tech solutions, which can be more easily implemented in the case of a global catastrophe. We show that equatorial regions’ temperatures under a 150 Tg (millions of tonnes of soot to the stratosphere) scenario of nuclear winter (around 15 °C average) are similar to summer temperatures in northern European regions of the former Soviet Union, which had functional agriculture. We identified the following main agricultural technologies which can be adapted: (a) cold-tolerant crops, first of all potatoes, but also rutabaga and fodder beet; (b) frost-protection technologies (night-covering, watering, bottles with water); (c) silage production in pits for animal feeding; (d) and low-labor-demanding crops. One meta lesson is making several bets on different food-producing technologies in the situation of risky agricultural practices. These findings contribute to Sustainable Development Goal 2 (Zero Hunger) and highlight how historically validated, low-input agricultural knowledge can underpin sustainable food system resilience under extreme climate disruption. Full article

Metals are widely used in various types of structural applications such as the automotive, aerospace and construction industries. However, their service life is limited due to the various loads they experience during operation. Specifically, cyclic loading can lead to the early fatigue failure of these structures. Therefore, early detection of fatigue deformation is essential to prevent catastrophic failures. In this study, an automated electrical resistance data acquisition system was developed using LabVIEW to obtain measurements from a Keithley 6221 current source for fatigue damage detection. The results showed an increase in electrical resistivity after the application of cyclic loading. It was observed that electrical resistivity increased after each set of loading cycles, with an average increase of 7.38%, a stress level of 260 MPa (high-cycle fatigue), and a 6.5% increase after the application of 25,000 cycles at 165 MPa (low-cycle fatigue). Scanning Transmission Electron Microscopy (S/TEM) was used for microstructural investigation as a proof of concept for the high-cycle fatigue sample interrupted after 25,000 cycles to analyse the modification in dislocation structures as well as a qualitative increment in the dislocation density with respect to the initial microstructural state of the as-machined sample. Such a modification in dislocation structures as well as an increment in dislocation density corroborates the findings proposed by electrical resistivity measurement. The results demonstrated that electrical resistivity measurement provides a promising non-destructive approach for the early detection of fatigue damage in metallic materials. Full article

To improve risk prevention and safety management in high-risk industrial systems, this study integrates energy transfer theory and system dynamics to analyze the mechanisms of major and extraordinary accidents. It further investigates the catastrophic explosion of Tianjiayi Chemical Co., Ltd. on 21 March 2019 in Xiangshui, China—a complex-system failure that caused extensive casualties and property damage. By refining the energy transfer model using system dynamics, the accident is analyzed through the lens of a hazardous energy constraint failure. Simulation results demonstrate that the incident arose from the coupled interaction of multi-level risk factors, exhibiting pronounced nonlinear and synergistic characteristics. The collapse of energy containment barriers led to an uncontrolled release of stored chemical energy, which critically escalated the accident. Personnel errors, managerial deficiencies, and material hazards were identified as primary contributors to systemic vulnerability. The findings offer a mechanistic understanding of energy-driven accident evolution and provide actionable insights for enhancing engineering safety management and preventing major accidents in chemical industrial parks. Full article

In aerospace manufacturing, validating heavy-duty automated production tooling and Ground Support Equipment (GSE) traditionally requires costly and time-consuming physical proof load testing. This study proposes a novel Virtual Certification framework that utilizes a high-fidelity Multiphysical Digital Twin driven by a Software-in-the-Loop (SiL) co-simulation architecture (integrating Siemens NX MCD, SIMIT, and TIA Portal) to retroactively diagnose mechanical failures and virtually validate design modifications prior to physical manufacturing. The dual-focus methodology is rigorously applied to a physical case study: an over-constrained (hyperstatic) 4-point aerospace lifting system designed for a 26.48 kN fuselage section that suffered a catastrophic mechanical stall during a 39.24 kN physical proof load verification. While conventional static dimensioning models erroneously predicted a nominal drive torque of only 4.56 Nm, the high-fidelity dynamic twin (incorporating a non-linear exponential Stribeck friction model) calculated the transient mechanical resistance causing the stall, capturing a peak load of 46.2 Nm at the motor shaft. The SiL co-simulation revealed that the rigid positional synchronization logic enforced by the PLC inadvertently amplified localized boundary friction, driving the actuators beyond their rated 6.4 Nm capacity. Based on this forensic diagnosis, a remedial powertrain featuring an 8.0 Nm stepper motor coupled with a 16:1 planetary gearbox was integrated and virtually certified. The framework confirmed that the upgraded architecture successfully attenuated the hyperstatic resistance, reflecting a peak load of only 3.0 Nm at the motor shaft and guaranteeing a stable Safety Factor of 2.66. By bridging the reality gap without iterative physical prototyping, this framework establishes a scalable, “First-Time-Right” validation paradigm for multi-point automated manufacturing mechanisms. Full article

This study investigates the synthesis, phase evolution, and high-temperature oxidation behavior of multi-component aluminide coatings on EP670 (Fe-Ni base), EP718 (Ni-Fe base), and EP648 (Ni-base) superalloys. The coatings were produced using an economical hot-dip aluminizing method, followed by diffusion heat treatment at 1100 °C. In the as-deposited state, the coatings exhibit a heterogeneous structure consisting of an aluminum matrix with various Al-rich intermetallic inclusions. Subsequent heat treatment promotes the redistribution of chemical elements, leading to the elimination of free aluminum and the stabilization of a protective β-phase matrix. Long-term oxidation tests were performed at 900 °C, 1100 °C, and 1300 °C for up to 1000 h. At 1100 °C, the coatings on EP670 and EP648 demonstrated high stability, following a near-parabolic oxidation law and significantly reducing mass gain compared to uncoated substrates. However, at 1100 °C, the EP718 alloy underwent catastrophic failure within 200 h due to pest oxidation, disintegrating into an oxide powder—a phenomenon quantitatively confirmed by the kinetic exponent dropping below 1.0. At 1300 °C, the thermal limit for all coatings was established, with protective properties failing after 50 h. Based on the aluminum depletion kinetics, the service life at 1100 °C was estimated at 1300 h for EP670 and 2200 h for EP648. Scratch testing confirmed a complete absence of interfacial adhesive cracks across all systems. Contact loading triggered only cohesive cracks localized within the near-surface zone of the coatings. The results highlight the superior thermodynamic compatibility of the EP670 and EP648 systems with aluminide coatings, making them the most suitable candidates for extreme high-temperature applications. Full article

Large language model (LLM) backends increasingly generate SSH-honeypot output, yet the literature fixes one backend per system and judges realism by human evaluators, never asking which LLM is fit to play the shell or measuring the catastrophic failure of a backend leaking its own instructions. We fix one hardened unprivileged user scaffold and prompt, vary only the backend across eleven LLMs, and replace the human judge with an objective, prompt-anchored leakage metric. Across a controlled 42-command battery (20 trials each; 8736 responses) and a live adaptive corpus (8626 responses), we score six dimensions: instruction leakage, fidelity, hallucination, latency, verbosity, and stability. Exactly one backend (gemma-4-31b-it) reproduces verbatim leakage in both datasets and is disqualified; the other ten never leak. A deterministic handler layer serves 33 of 42 commands identically across backends, confining model risk to nine generative commands, where flag fabrication ranges 0–95%, latency spans an order of magnitude, and a held-out classifier identifies the backend from one response at 71% versus 9% chance, a fingerprinting risk. We report a per-dimension scorecard rather than a weight-sensitive ranking. Honeypot safety on the privilege boundary is a property of the architecture; realism, speed, cost, and one catastrophic leak are properties of the model. Full article