233 research outputs found
Topological localization in out-of-equilibrium dissipative systems
In this paper we report that notions of topological protection can be applied
to stationary configurations that are driven far from equilibrium by active,
dissipative processes. We show this for physically two disparate cases :
stochastic networks governed by microscopic single particle dynamics as well as
collections of driven, interacting particles described by coarse-grained
hydrodynamic theory. In both cases, the presence of dissipative couplings to
the environment that break time reversal symmetry are crucial to ensuring
topologically protection. These examples constitute proof of principle that
notions of topological protection, established in the context of electronic and
mechanical systems, do indeed extend generically to processes that operate out
of equilibrium. Such topologically robust boundary modes have implications for
both biological and synthetic systems.Comment: 11 pages, 4 figures (SI: 8 pages 3 figures
Implementing new interpretation oriented tools in KLASS to support decision making based on logistic regression
This project is part of an research line of combination of statistics methods and Artificial Intelligence for Knowledge Discovery in ill-structured real domains. At the end of this project KLASS contains the following functionalities: predictive models, dummies management and variables aggregation
Protein-induced membrane curvature changes membrane tension
Adsorption of proteins onto membranes can alter the local membrane curvature.
This phenomenon has been observed in biological processes such as endocytosis,
tubulation and vesiculation. However, it is not clear how the local surface
properties of the membrane, such as membrane tension, change in response to
protein adsorption. In this paper, we show that the classical elastic model of
lipid membranes cannot account for simultaneous changes in shape and membrane
tension due to protein adsorption in a local region, and a viscous-elastic
formulation is necessary to fully describe the system. Therefore, we develop a
viscous-elastic model for inhomogeneous membranes of the Helfrich type. Using
the new viscous-elastic model, we find that the lipids flow to accommodate
changes in membrane curvature during protein adsorption. We show that, at the
end of protein adsorption process, the system sustains a residual local tension
to balance the difference between the actual mean curvature and the imposed
spontaneous curvatures. This change in membrane tension can have a functional
impact in many biological phenomena where proteins interact with membranes.Comment: 15 pages, 5 figure
Exploring Quantum-Enhanced Machine Learning for Computer Vision: Applications and Insights on Noisy Intermediate-Scale Quantum Devices
As medium-scale quantum computers progress, the application of quantum
algorithms across diverse fields like simulating physical systems, chemistry,
optimization, and cryptography becomes more prevalent. However, these quantum
computers, known as Noisy Intermediate Scale Quantum (NISQ), are susceptible to
noise, prompting the search for applications that can capitalize on quantum
advantage without extensive error correction procedures. Since, Machine
Learning (ML), particularly Deep Learning (DL), faces challenges due to
resource-intensive training and algorithmic opacity. Therefore, this study
explores the intersection of quantum computing and ML, focusing on computer
vision tasks. Specifically, it evaluates the effectiveness of hybrid
quantum-classical algorithms, such as the data re-uploading scheme and the
patch Generative Adversarial Networks (GAN) model, on small-scale quantum
devices. Through practical implementation and testing, the study reveals
comparable or superior performance of these algorithms compared to classical
counterparts, highlighting the potential of leveraging quantum algorithms in ML
tasks
The irreversible thermodynamics of curved lipid membranes
The theory of irreversible thermodynamics for arbitrarily curved lipid
membranes is presented here. The coupling between elastic bending and
irreversible processes such as intra-membrane lipid flow, intra-membrane phase
transitions, and protein binding and diffusion is studied. The forms of the
entropy production for the irreversible processes are obtained, and the
corresponding thermodynamic forces and fluxes are identified. Employing the
linear irreversible thermodynamic framework, the governing equations of motion
along with appropriate boundary conditions are provided.Comment: 62 pages, 4 figure
AUTOMATED HUMAN ACTIVITY RECOGNITION FROM CONTROLLED ENVIRONMENT VIDEOS
This thesis explores deep learning methods for Human Activity Recognition (HAR) from videos to automate the annotation of human activities in videos. The research is particularly relevant for continuous monitoring in healthcare settings such as nursing homes and hospitals. The innovative part of the approach lies in using YOLO models to first detect humans in video frames and then isolating them from the rest of the image for activity recognition which leads to an improvement in accuracy. The study employs pre-trained deep residual networks, such as ResNet50, ResNet152-V2, and Inception-ResNetV2, which were found to work better than custom CNN-based models. The methodology involved extracting frames at one-minute intervals from 12-hour-long videos of 18 subjects and using this data for training and testing the models for human activity recognition. This thesis contributes to HAR research by demonstrating the effectiveness of combining deep learning with advanced image processing, suggesting new directions for healthcare monitoring applications
Arbitrary Lagrangian–Eulerian finite element method for curved and deforming surfaces: I. General theory and application to fluid interfaces
An arbitrary Lagrangian–Eulerian (ALE) finite element method for arbitrarily curved and deforming two-dimensional materials and interfaces is presented here. An ALE theory is developed by endowing the surface with a mesh whose in-plane velocity need not depend on the in-plane material velocity, and can be specified arbitrarily. A finite element implementation of the theory is formulated and applied to curved and deforming surfaces with in-plane incompressible flows. Numerical inf–sup instabilities associated with in-plane incompressibility are removed by locally projecting the surface tension onto a discontinuous space of piecewise linear functions. The general isoparametric finite element method, based on an arbitrary surface parametrization with curvilinear coordinates, is tested and validated against several numerical benchmarks. A new physical insight is obtained by applying the ALE developments to cylindrical fluid films, which are computationally and analytically found to be stable to non-axisymmetric perturbations, and unstable with respect to long-wavelength axisymmetric perturbations when their length exceeds their circumference. A Lagrangian scheme is attained as a special case of the ALE formulation. Though unable to model fluid films with sustained shear flows, the Lagrangian scheme is validated by reproducing the cylindrical instability. However, relative to the ALE results, the Lagrangian simulations are found to have spatially unresolved regions with few nodes, and thus larger errors
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