Results 151 to 160 of about 9,480,449 (227)
ABSTRACT A repairable system operates under a maintenance strategy involving scheduled preventive maintenance (PM) and corrective repair actions following failures. This study develops an exact analytical methodology using Markov chains with discrete states and time to calculate the expected number of failures E[N(t)]$\mathop {\mathbb {E}}[N(t)]$ under
Danilo G. O. Valadares +3 more
wiley +1 more source
Weibull Variational Autoencoder for Remaining Useful Life Prediction
ABSTRACT Remaining useful life (RUL) prediction is a critical technology for preventing unexpected failures and reducing maintenance costs in modern industrial systems. However, traditional model‐based approaches are limited by the need for explicit mathematical modeling of degradation mechanisms, while data‐driven methods often require large‐scale ...
JunWoo Yu +4 more
wiley +1 more source
Sliding Mode Control in Aerospace Applications: A Survey
ABSTRACT Sliding mode control (SMC) enjoys robustness to matched and unmatched (in the case of minimum phase input‐output dynamics) bounded perturbations, and finite time convergence. Second‐order and higher‐order sliding mode control systems (2‐SMC/HOSMC) retain all the advantages of sliding mode control, but in addition can be applied to systems of ...
Yuri Shtessel, Christopher Edwards
wiley +1 more source
Deep Reinforcement Learning‐Based Control for Real‐Time Hybrid Simulation of Civil Structures
ABSTRACT Real‐time Hybrid Simulation (RTHS) is a cyber‐physical technique that studies the dynamic behavior of a system by combining physical and numerical components that are coupled through a boundary condition enforcer. In structural engineering, the numerical components are subjected to environmental loads that become dynamic displacements of the ...
Andrés Felipe Niño +6 more
wiley +1 more source
ABSTRACT Uncrewed underwater vehicles (UUVs) have transformed oceanographic research through autonomous data gathering. Similarly, lake and other aquatic research can potentially be automated and transformed. However, UUVs would need to be smaller, lighter, less complex, and cheaper than currently available to make them more practical and user‐friendly
James M Rand +3 more
wiley +1 more source
ABSTRACT Flow velocity measurement is fundamental to hydrological and hydraulic studies, providing essential data for streamflow estimation and river dynamics analysis. Traditional in situ methods like propeller gauges and acoustic Doppler current profilers are accurate but intrusive and labour‐intensive, while non‐intrusive image processing methods ...
Ghazaleh Nassaji Matin +4 more
wiley +1 more source
We evaluated single‐ and multi‐sensor UAV approaches for classifying tree species and standing dead trees in boreal forests, focusing on key biodiversity indicators such as European aspen. Using spectral and structural features extracted from RGB, multispectral (MSP), and LiDAR point clouds for 1,205 field‐measured trees, we compared classification ...
Anton Kuzmin +5 more
wiley +1 more source
Accounting for animal movement during aerial imaging surveys
Animals are not stationary during aerial surveys; if their movements are related to the movement of the aerial platform, then bias can be introduced into subsequent population count estimates. We sought to establish a framework for assessing the impacts of animal movement on count error and platform bias by comparing aggregated counts and relative ...
Rowan L. Converse +5 more
wiley +1 more source
Cycles of dieback and recovery drove mangrove forest dynamics at the Albert and Leichhardt Rivers (Gulf of Carpentaria, Queensland, Australia) over 36 years (1987–2023). Landward margins were the most affected by reduced tidal inundation when the alignment of low lunar declination suppressed tidal range and extreme El Niño phases lowered mean sea level.
Rogerio Victor S. Gonçalves +4 more
wiley +1 more source
This study evaluates the performances of synchronous aerial visible (VIS) and thermal infrared (TIR) imagery for detecting great blue heron (Ardea herodias) nests and individuals using a YOLO11n model. VIS and TIR images were automatically aligned using deep learning, and both early and late fusion approaches were tested.
Camille Dionne‐Pierre +6 more
wiley +1 more source

