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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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12.5%25.0%37.5%50.0% · May 199319922001200920182026
48 results for normal vector reconstruction

New photometric stereo method using dictionary learning for better normal vector reconstruction.

problem Photometric stereo's reliance on diffuse surface model limits its effectiveness for complex reflectance patterns.
method Developed two formulations of dictionary learning for photometric stereo: one for Lambertian and one for non-Lambertian objects.
result State-of-the-art performance compared to existing robust photometric stereo methods on synthetic and real datasets.

Paper proposes RAN for better anomaly detection in time series data.

problem Anomaly detection algorithms often fail to accurately detect anomalies due to incomplete reconstruction of anomaly data.
method RAN uses adversarial learning and latent vector-constrained Autoencoder to ensure consistent reconstruction of anomaly data.
result RAN outperforms other algorithms in detecting meaningful anomalies with higher AUC-ROC scores.

Paper presents a method for robust surface reconstruction from noisy gradients using adaptive dictionary learning.

problem Reconstructing surfaces from noisy photometric stereo normal vector maps.
method Adaptive dictionary learning to sparsely represent spatial patches of the surface, enforcing smoothness constraints.
result The method effectively learns the underlying surface structure and is robust to noise.

A singular foliation on a complete riemannian manifold M is said to be riemannian if each geodesic that is perpendicular at one point to a leaf remains perpendicular to every leaf it meets. We prove that the regular leaves are equifocal, i.e., the end point map of a normal foliated vector field has constant rank. This …

2007-04-24abs ↗pdf ↗

We give reconstruction formulas inverting the geodesic X-ray transform over functions (call it I0I_0) and solenoidal vector fields on surfaces with negative curvature and strictly convex boundary. These formulas generalize the Pestov-Uhlmann formulas in [Pestov-Uhlmann, IMRN '04] (established for simple surfaces) to ca…

2015-11-17abs ↗pdf ↗

This article concerns cotangent-lifted Lie group actions; our goal is to find local and ``semi-global'' normal forms for these and associated structures. Our main result is a constructive cotangent bundle slice theorem that extends the Hamiltonian slice theorem of Marle, Guillemin and Sternberg. The result applies to a…

2004-09-09abs ↗pdf ↗

The paper proposes methods to find a shared active subspace for multivariate vector-valued functions.

problem Minimizing the deviation between function evaluations in the original and reconstructed spaces.
method Manipulating gradients or SPD matrices to identify a shared structure.
result Summing SPD matrices often identifies the best shared active subspace.

Fine-tuning normalization layers can reconstruct smaller networks.

problem Understanding the expressive power of fine-tuning normalization layers.
method Random ReLU networks and sparsified networks were fine-tuned to reconstruct target networks.
result Fine-tuning normalization layers can reconstruct networks that are O(extwidth)O(\sqrt{ ext{width}}) times smaller.

Improved physics-integrated generative models with noise robustness and fidelity.

problem Enhancing generative models to produce outputs that comply with physical laws and improve generalization.
method Integrating variational autoencoder with planar normalizing flow and attention mechanisms to learn latent posterior distributions and mitigate noise.
result Significant improvement in reconstruction quality and robustness against noise.

This work compares meta-embeddings for natural language processing tasks.

problem Improving distributed word representations in natural language processing.
method Meta-embeddings trained with angular and normalized distance loss functions compared to standard loss functions.
result Normalization methods outperform standard loss functions on word similarity datasets.

Proves formula for reconstruction performance in generalized linear models.

problem Analyzing reconstruction performance in generalized linear models with arbitrary bounded spectrum.
method Message passing algorithms and dynamical system stability analysis.
result Analytical formula confirms replica method conjecture for convex models.

This paper is concerned with the question of reconstructing a vector in a finite-dimensional real Hilbert space when only the magnitudes of the coefficients of the vector under a redundant linear map are known. We analyze various Lipschitz bounds of the nonlinear analysis map and we establish theoretical performance bo…

2013-08-21abs ↗pdf ↗

Reconstructing signature features from randomized vector fields in differential equations.

problem Reconstructing signature features from controlled differential equations with random vector fields.
method Using controlled ordinary differential equations driven by continuous bounded variation curves, the study explores the extent to which signature features can be reconstructed from the non-linear flow of these equations.
result The number of signature features that can be reconstructed from the non-linear flow of controlled ordinary differential equations with random vector fields is exponential in the hidden dimension, under certain conditions.

Normalizing flows improve ptychography reconstruction quality and uncertainty quantification.

problem Challenges in ptychography due to large-scale nonlinear and non-convex inverse problems and photon statistics.
method Use of normalizing flows to model the posterior distribution and quantify reconstruction uncertainty.
result Normalizing flows enable better characterization and uncertainty quantification in ptychography reconstructions.

In this note we answer a question of G. Lecué, by showing that column normalization of a random matrix with iid entries need not lead to good sparse recovery properties, even if the generating random variable has a reasonable moment growth. Specifically, for every 2pc1logd2 \leq p \leq c_1\log d we construct a random vector …

2017-02-21abs ↗pdf ↗

A new multi-scale vector quantization method for unsupervised data.

problem Efficiently reconstructing unsupervised data with minimal distortion.
method Reconstruction trees, inspired by decision trees, explore data in a multi-scale fashion.
result Analysis of expected distortion under fixed unknown distribution, with asymptotic and finite sample results.

RADAR uses diffusion models to detect anomalies without reconstruction, improving accuracy and efficiency.

problem Challenges in anomaly detection and segmentation, especially in real-time applications.
method RADAR uses attention-based diffusion models to directly produce anomaly maps from the diffusion process, bypassing reconstruction.
result RADAR improves F1 score by 7% on MVTec-AD and 13% on 3D-printed material compared to state-of-the-art methods.

Proposes a novel method for generating hard negatives near time series data boundaries.

problem Challenges in generating effective negative samples for time series anomaly detection.
method Reconstruction-driven boundary negative generation framework using reinforcement learning.
result Improves anomaly representation learning and achieves competitive detection performance.

SaR-SVM-STV improves hyperspectral image classification with shape-adaptive reconstruction and denoising.

problem Classifying hyperspectral images with limited labeled data.
method Shape-adaptive Reconstruction (SaR) for pixel preprocessing, SVM for probability estimation, and Smoothed Total Variation (STV) for denoising.
result SaR-SVM-STV outperforms SVM-STV with fewer labeled data.

Reconstructing polytopes with fixed facet directions from support function evaluations.

problem Reconstructing polytopes with known facet directions from limited data.
method Least-squares estimate via convex quadratic program, combinatorial characterization for uniqueness, algorithm convergence.
result The least-squares estimate for a fixed simplicial normal fan is a convex quadratic program, and the solution is unique under certain conditions.

We introduce the problem of reconstructing a sequence of multidimensional real vectors where some of the data are missing. This problem contains regression and mapping inversion as particular cases where the pattern of missing data is independent of the sequence index. The problem is hard because it involves possibly m…

2011-09-15abs ↗pdf ↗

The paper explores Parseval frames on vector bundles, proving their existence for certain cases.

problem Existence of Parseval frames on vector bundles.
method Using GG-bundles and algebraic topology, the authors prove the existence of Parseval frames for orientable vector bundles and provide conditions for smaller size frames.
result The existence of Parseval frames for orientable vector bundles and conditions for smaller size frames.

Proposes a novel method for detecting novelty in multi-modal data.

problem Challenges in detecting novelty in high-dimensional, multi-modal data.
method Orthogonalized latent space for disentangling features and defining novelty score.
result Proposed method outperforms state-of-the-art algorithms in novelty detection.

Boosts neural network performance by improving weight separability.

problem Improving the separability of weight vectors in neural networks.
method Proposes a new evaluation metric and feed-backward reconstruction loss to encourage weight separability.
result Improves visual recognition performance across various tasks.

3D dust map of the Milky Way improves resolution and accuracy.

problem Reconstructing the 3D dust distribution in the Milky Way.
method Gaussian process regression on spherical coordinates with iterative grid refinement.
result Improved 3D dust map with increased resolution and accuracy.

The Funk-Minkowski transform and spherical convolution reconstruct functions and vector fields on the sphere.

problem Reconstructing functions and vector fields on the sphere using Funk-Minkowski transform and Hilbert type spherical convolution.
method Inversion formula for Funk-Minkowski transform and Helmholtz-Hodge decomposition solution using spherical convolution.
result Complete reconstruction of functions and vector fields on the sphere.

The paper proves a Minkowski-like theorem for tetrahedra in dS3 and AdS3.

problem Formulating and proving a constant-curvature, holonomy-valued Lorentzian analogue of Minkowski theorem for tetrahedra.
method Formulated and proved a Lorentzian analogue of Minkowski theorem for tetrahedra in dS3 and AdS3.
result A unique strictly convex tetrahedron can be reconstructed from four non-trivial based SO+(1,2) holonomies.

We develop a non-relativistic twistor theory, in which Newton--Cartan structures of Newtonian gravity correspond to complex three-manifolds with a four-parameter family of rational curves with normal bundle OO(2){\mathcal O}\oplus{\mathcal O}(2). We show that the Newton--Cartan space-times are unstable under the general K…

2015-02-10abs ↗pdf ↗

The paper recovers contact forms from boundary data using vector fields and Lyapunov functions.

problem Recovering contact forms from boundary data.
method Using vector fields and Lyapunov functions, the paper describes boundary data and proves reconstruction of (X,β)(X, β) up to diffeomorphism.
result Boundary data allow for the reconstruction of (X,β)(X, β) up to a diffeomorphism of XX.

Belief Propagation outperforms other algorithms in reconstructing binary symmetric channel trees.

problem Reconstructing binary symmetric channel trees with bounded memory.
method Combining recursive reconstruction, information theory, and optimal transport.
result Any recursive algorithm with bounded memory for the reconstruction problem on binary symmetric channel trees has a phase transition strictly below the Belief Propagation threshold.

Two strategies for embedding new data points from proximity data are explored.

problem Embedding new data points using proximity data.
method Two competing strategies: projection and restricted reconstruction.
result Projection and restricted reconstruction can be derived from kernel methods.

Improved image reconstruction and anomaly detection using hierarchical VAEs.

problem VAEs struggle with sharp images and high-level features.
method Added a new branch to hierarchical VAEs to separate high-level and low-level features.
result Results in sharper images and better anomaly detection.

The normal map of curves is analyzed as a vector field on a cylinder.

problem Understanding the geometric properties of normal maps and their vector field interpretation.
method Interpreting critical points geometrically, studying Poincaré index, projecting to sphere, and analyzing winding and rotation indices.
result Counting theorems regarding winding and rotation indices of curves and their evolutes are proven.

Study improves self-normalized bounds for vector-valued processes beyond sub-Gaussianity.

problem Limited understanding of self-normalized concentration for vector-valued processes outside sub-Gaussian frameworks.
method Developed concentration inequalities for self-normalized processes with light tails (e.g., Bennett, Bernstein bounds) for vector-valued data.
result Provided new insights and bounds for self-normalized processes with non-sub-Gaussian distributions.

Article studies symmetry in smooth vector bundles using advanced operations.

problem Symmetry phenomena in smooth vector bundles after two iterations of the normal functor.
method Developed theory of pullback and quotient for double vector bundles and morphisms, focusing on naturality of the normal functor.
result Expected symmetry is obtained through universal behavior and compatibility of operations.