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arXiv research

A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

169,181 papers · 148 categories

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69138207276 · Jun 202019922001200920182026
48 results for dynamic PET

Factor analysis improves PET image interpretation by considering non-standard noise distributions.

problem Improving interpretation of dynamic PET images with non-standard noise distributions.
method Proposes using β\beta-divergence to fit factor models for different noise distributions.
result Improves factor analysis results for various noise types in PET images.

A new probabilistic model for PET image reconstruction.

problem Conventional PET image reconstruction ignores uncertainty in TACs.
method Probabilistic Graphical Modeling (PGM) with gradient-based iterative algorithm.
result Incorporates uncertainty in TACs, improving image reconstruction.

Deep neural networks improve PET attenuation correction from MR images.

problem Challenges in PET attenuation correction from MR images in PET/MR hybrid systems.
method Deep neural networks, specifically U-net and GroupU-net structures, to derive continuous attenuation coefficients.
result Proposed neural network methods outperform standard methods in PET quantification accuracy.

PETNet improves AD diagnosis using graph-based CNN on PET images.

problem Early diagnosis of Alzheimer's Disease using PET imaging.
method PETNet, a graph-based CNN architecture for 3D PET image analysis.
result PETNet shows improved performance over deep learning and other methods on ADNI dataset.

PETS combines deep networks with uncertainty to match model-free RL's performance with fewer samples.

problem Lack of sample efficiency in model-based RL with deep networks.
method Probabilistic ensembles with trajectory sampling (PETS) using uncertainty-aware dynamics models.
result Matches model-free RL's asymptotic performance with significantly fewer samples.

BCD-Net improves PET image reconstruction in low-count scenarios.

problem Low-count PET imaging challenges due to high random fractions and low SNR.
method Modified BCD-Net architecture for iterative neural network-based PET image reconstruction.
result BCD-Net significantly improves CNR and RMSE of reconstructed images compared to traditional methods.

A new Bayesian MBRL method improves performance in robotics tasks.

problem Enhancing model-based reinforcement learning with uncertainty.
method Introduces variational inference MPC and probabilistic action ensembles with trajectory sampling (PaETS).
result Consistently improves performance on challenging locomotion tasks.

Deep neural network improves PET image quality using inter-patient information.

problem Challenges in PET image reconstruction due to ill-posedness and limited photon detection.
method Trained a deep residual convolutional neural network in an iterative PET image reconstruction framework using ADMM.
result Proposed method outperforms neural network denoising and conventional methods in quantification.

KCS improves parametric maps from PET images by reducing noise and variance.

problem Improving the quality of parametric maps from PET images due to noise.
method Kinetic Compressive Sensing (KCS) method based on a hierarchical Bayesian model and novel reconstruction algorithm.
result KCS produces spatially coherent images and parametric maps with lower noise and better contrast.

A key prerequisite to optimal reasoning under uncertainty in intelligent systems is to start with good class probability estimates. This paper improves on the current best probability estimation trees (Bagged-PETs) and also presents a new ensemble-based algorithm (MOB-ESP). Comparisons are made using several benchmark …

2012-07-11abs ↗pdf ↗

Framework for reproducible AD classification experiments using MRI and PET data.

problem Difficulty in reproducing and objectively comparing machine learning methods for Alzheimer's disease.
method Automatic conversion of datasets, modular preprocessing pipelines, feature extraction, and classification methods; evaluation framework.
result FDG PET outperformed T1 MRI, and classifiers trained on ADNI generalized well to other datasets.

Study compares MRI and PET for Alzheimer's classification using deep learning.

problem Balanced comparison of MRI and PET for Alzheimer's disease classification.
method Deep learning with ADNI dataset, fusion of MRI and PET.
result Deep learning shows benefits of using both MRI and PET for Alzheimer's classification.

This paper combines deep learning with medical imaging models to improve reconstruction speed and reduce radiation.

problem Medical imaging issues like slow MRI, radiation injury in CT and PET.
method Combining deep learning with model-based reconstruction.
result Improves reconstruction speed and reduces radiation in medical imaging.

InVA models image outcomes from multiple modalities, outperforming standard VAEs.

problem Understanding relationships across multiple imaging modalities in neuroimaging.
method Integrative Variational Autoencoder (InVA) framework for image-on-image regression.
result InVA accurately predicts PET scans from structural MRI, outperforming conventional models.

New method uses MRI data to improve PET tomography uncertainty quantification.

problem Improving uncertainty quantification in emission tomography with multimodal data.
method Nonparametric posterior learning technique adapted for Poisson-type data.
result Sampling algorithms are scalable, parallelizable, and easy to implement.

Enhances disease progression modeling using LLMs for complex brain connectivity.

problem Inaccurate predictions of disease spread due to oversimplified brain connectivity models.
method Uses LLMs to synthesize multi-modal relationships and learn disease trajectories from longitudinal data.
result Superior prediction accuracy and interpretability compared to traditional methods.

DIVE models brain disease progression with high spatial resolution.

problem Reconstruct long-term brain pathology from short-term data.
method Clusters vertex-wise biomarker measurements, estimates average trajectories, and identifies disease-specific patterns.
result Reveals distinct patterns of pathology in different diseases and biomarker types.

Paper proposes a reproducible framework for Alzheimer's disease classification using ADNI data.

problem Lack of reproducible comparison between machine learning approaches in Alzheimer's disease classification.
method Automated database conversion, modular Nipype architecture, feature extraction pipelines, and reproducible classification techniques.
result Highest accuracies achieved for various Alzheimer's disease subtypes.

Improves U-Net for scale equivariance in semantic segmentation.

problem Improving generalization in semantic segmentation tasks with varying scales.
method Introduces Scale Equivariant U-Net (SEU-Net) with carefully applied subsampling and upsampling layers and scale-equivariant layers.
result Significantly improved generalization to different scales compared to U-Net and scale-equivariant architecture without upsampling.

fcHMRF-LIS controls FDR in neuroimaging data, improving power and scalability.

problem Complex spatial dependencies and high variability in FDR control methods for neuroimaging data.
method fcHMRF-LIS integrates LIS-based testing with fcHMRF to model spatial structures efficiently.
result fcHMRF-LIS achieves accurate FDR control, lower FNR, and higher true positives compared to existing methods.

Traditional voxel-level multiple testing procedures in neuroimaging, mostly pp-value based, often ignore the spatial correlations among neighboring voxels and thus suffer from substantial loss of power. We extend the local-significance-index based procedure originally developed for the hidden Markov chain models, whic…

2014-04-04abs ↗pdf ↗

DeepFDR uses deep learning for better FDR control in neuroimaging data.

problem Spatial dependence among voxel-based tests in neuroimaging data.
method DeepFDR leverages unsupervised deep learning-based image segmentation.
result DeepFDR outperforms existing methods in FDR control and computational efficiency.

Novel Bayesian framework for Poisson inverse problems using Bregman geometry.

problem Solving Poisson inverse problems with non-Euclidean geometry and positivity constraints.
method Develops a Monte Carlo sampling algorithm that accounts for Bregman geometry, data augmentations, and conditional conjugacy properties.
result Efficient sampling via Gibbs steps and Hessian Riemannian Langevin Monte Carlo (HRLMC) for positivity constraints.

AutoAugment learns optimal data augmentation policies automatically.

problem Improving image classifier accuracy through better data augmentation.
method AutoAugment uses a search algorithm to find the best augmentation policies in a defined search space.
result AutoAugment achieves state-of-the-art accuracy on multiple datasets.

New methods tackle complex inverse problems with scalable optimization-based MCMC.

problem Estimating high-dimensional model parameters and hyperparameters in nonlinear hierarchical statistical inverse problems.
method Optimization-based Markov chain Monte Carlo (MCMC) methods using RTO and pseudo-marginal MCMC.
result Efficient sampling tools for hierarchical Bayesian inversion with robust performance to model parameter dimensions.

Study on 2-valued dynamics on complex plane, showing some dynamics can't be group actions.

problem Whether 2-valued dynamics can be defined by the action of a 2-valued group.
method Construction of examples of dynamics that are or are not group actions.
result Some 2-valued dynamics on complex plane cannot be defined by the action of a 2-valued group.

The paper studies dynamic star-shaped risk measures and their representation.

problem Representing dynamic star-shaped risk measures and their properties.
method Representation theorems for dynamic monetary and star-shaped risk measures.
result Dynamic star-shaped risk measures can be represented as the lower envelope of a family of dynamic convex risk measures.

The paper provides a representation for dynamic risk measures and capital allocations.

problem Representation of dynamic risk measures and capital allocations under Itô-Lévy model.
method Representation theorem for dynamic capital allocation derived from BSDEs with quadratic-exponential growth.
result Derivation of a capital allocation representation for dynamic entropic risk measure and static coherent risk measure.

DOODL learns shared spectral dynamics across related dynamical systems.

problem Learning independent dynamical operators for each system limits discovery of shared structure.
method DOODL learns a dictionary of characteristic spectral dynamics on a manifold of related systems.
result DOODL achieves errors one to two orders of magnitude lower than independent operator estimation methods.

We propose a new class of mappings, called Dynamic Limit Growth Indices, that are designed to measure the long-run performance of a financial portfolio in discrete time setup. We study various important properties for this new class of measures, and in particular, we provide necessary and sufficient condition for a Dyn…

2013-12-04abs ↗pdf ↗

Develops a new framework to understand MCMC dynamics as flows on Wasserstein space.

problem Lack of understanding general MCMC dynamics in terms of flows on Wasserstein space.
method Introduces novel concepts to recognize MCMC dynamics as fiber-gradient Hamiltonian flows on Wasserstein space.
result Enables ParVI simulation of MCMC dynamics, enriching ParVI family with more efficient dynamics.