A computational method for quantifying left ventricle (LV) remodeling using 3D mesh models reconstructed from magnetic resonance imaging is proposed. The underlying geometry of the LV mesh is obtained by using a quadric fitting method, and its quantification is performed by using a curvedness shape descriptor. To achieve robustness, we have performed detailed studies of the effects of n-ring parameter selection on the accuracy of this method with in vitro and in vivo LV models. We have found that curvedness calculations based on a 5-ring selection can accurately depict anomalies in LV shape despite the presence of noise due to manual image segmentation. Our studies show that patients after myocardial infarction exhibit significant LV shape alteration in terms of curvedness, in particular at the apex. The diastole-to-systole change in regional curvedness was significantly lower suggesting regional differences in hypokinesis due to infarcted myocardium. This approach may add new insights into ventricular deformation and enable better discrimination between normal and pathologic conditions.
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http://dx.doi.org/10.1016/j.cmpb.2011.03.008 | DOI Listing |
Sci Rep
January 2025
Department of Information Systems, College of Computing and Informatics, The University of Sharjah, Sharjah, UAE.
This study explores the integration of nanotechnology and Long Short-Term Memory (LSTM) machine learning algorithms to enhance the understanding and optimization of fuel spray dynamics in compression ignition (CI) engines with varying bowl geometries. The incorporation of nanotechnology, through the addition of nanoparticles to conventional fuels, improves fuel atomization, combustion efficiency, and emission control. Simultaneously, LSTM models are employed to analyze and predict the complex spray behavior under diverse operational and geometric conditions.
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January 2025
Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
Sampling is a pivotal element in the design of metasurfaces, enabling a broad spectrum of applications. Despite its flexibility, sampling can result in reduced efficiency and unintended diffractions, which are more pronounced at high numerical aperture or shorter wavelengths, e.g.
View Article and Find Full Text PDFHeliyon
December 2024
Higher Institute for Applied Sciences and Technology (HIAST), Damascus, P.O.Box 31983, Syria.
The precision and safety of robotic applications rely on accurate robot models. Bayesian Neural Networks (BNNs) offer the capability to acquire intricate models and provide insights into inherent uncertainties. While recent studies have successfully employed machine learning to predict the Forward Geometric Model (FGM) of a 6-DOF (degrees of freedom) parallel manipulator, traditional methods lack predictive uncertainty estimation.
View Article and Find Full Text PDFSpat Stat
March 2024
United States Environmental Protection Agency, 200 SW 35th St, Corvallis, OR, USA.
Conductivity is an important indicator of the health of aquatic ecosystems. We model large amounts of lake conductivity data collected as part of the United States Environmental Protection Agency's National Lakes Assessment using spatial indexing, a flexible and efficient approach to fitting spatial statistical models to big data sets. Spatial indexing is capable of accommodating various spatial covariance structures as well as features like random effects, geometric anisotropy, partition factors, and non-Euclidean topologies.
View Article and Find Full Text PDFActa Sci Math
July 2024
HUN-REN Alfréd Rényi Institute of Mathematics, Reáltanoda U. 13-15, Budapest, H-1053 Hungary.
The seminal work of Kubo and Ando (Math Ann 246:205-224, 1979/80) provided us with an axiomatic approach to means of positive operators. As most of their axioms are algebraic in nature, this approach has a clear algebraic flavour. On the other hand, it is highly natural to take the geomeric viewpoint and consider a distance (understood in a broad sense) on the cone of positive operators, and define the mean of positive operators by an appropriate notion of the center of mass.
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