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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.

169,051 papers · 148 categories

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75149224298 · Jun 202019922001200920182026
48 results for Discrete cosine transform

We extend the Fourier cosine method to discrete probability distributions, achieving faster convergence rates.

problem Extending Fourier cosine method to discrete probability distributions.
method Spectral filters and convergence rates analysis.
result Spectral filters achieve one order faster convergence rates than previously recognized.

We introduce a new discretization of O'Hara's Möbius energy. In contrast to the known discretizations of Simon and Kim and Kusner it is invariant under Möbius transformations of the surrounding space. The starting point for this new discretization is the cosine formula of Doyle and Schramm. We then show ΓΓ-convergence…

2018-09-21abs ↗pdf ↗

New algorithm defends against adversarial examples in image classification.

problem Defending against adversarial examples in image classification.
method Approximates Discrete Fourier transform of sparse signals corrupted by L0L_0 noise.
result Successfully defends against L0L_0 adversaries in image classification.

The spherical Radon transform on the unit sphere can be regarded as a member of the analytic family of suitably normalized generalized cosine transforms. We derive new formulas for these transforms and apply them to study classes of intersections bodies in convex geometry.

2006-02-24abs ↗pdf ↗

We study rigidity of polyhedral surfaces and the moduli space of polyhedral surfaces using variational principles. Curvature like quantities for polyhedral surfaces are introduced. Many of them are shown to determine the polyhedral metric up to isometry. The action functionals in the variational approaches are derived …

2006-12-22abs ↗pdf ↗

Improved text classification performance through conformal transformations of kernels.

problem Text document categorization in high-dimensional spaces.
method Introduced new Gaussian Cosine kernel and two conformal transformations.
result Conformal transformations significantly improve kernel performance, especially for sub-optimal kernels.

The paper proposes efficient dictionary learning algorithms that avoid multiplications for sparse representations.

problem Sparse representation with reduced computational complexity.
method Factorizations of the dictionary into binary orthonormal, scaling, and shear transformations with closed-form solutions.
result The proposed methods are effective and can be compared to well-known transforms like FFT and DCT.

A new MLDS model captures nonlinear tensor time series with improved accuracy and efficiency.

problem Modeling and analyzing nonlinear tensor time series data.
method Transform-based multilinear dynamical system (MLDS) with EM algorithm for parameter estimation.
result Significantly higher prediction accuracy and exponential improvement in training time compared to state-of-the-art models.

Paper proposes graph-based separable transforms for video coding.

problem Improving video coding efficiency by better capturing residual block statistics.
method Derives graph-based separable transforms (GBSTs) from line graphs with weights determined by parameters.
result GBSTs achieve about 0.4% average coding gain over existing transforms in VVC.

Proposes AWS method for precise speech enhancement using DNN.

problem T-F resolution problem in fixed-resolution short-time frequency transforms.
method Incorporates trainable adaptive window switching into speech enhancement procedure.
result Achieved higher signal-to-distortion ratio than conventional methods.

A new quasi-Newton method tackles NMF with transform learning on orthogonal manifolds.

problem Efficiently learning transforms for NMF in non-convex optimization on orthogonal manifolds.
method Derives a quasi-Newton method on the orthogonal matrix manifold using sparse approximations of the Hessian.
result Outperforms state-of-the-art methods by orders of magnitude in experiments on synthetic and real audio data.

The LpL^p-cosine transform of an even, continuous function $f\in C_e(\Sn)$ is defined by: $$H(x)=\int_{\Sn}|\ip{x}ξ|^pf(ξ) dξ,\quad x\in {\R}^n.$$ It is shown that if pp is not an even integer then all partial derivatives of even order of H(x)H(x) up to order p+1p+1 (including p+1p+1 if pp is an odd integer) exist and ar…

2001-11-27abs ↗pdf ↗

A new topology design improves zero-shot classification performance in contrastive learning.

problem Improving zero-shot classification performance in contrastive visual-textual alignment.
method Proposed an alternative topology design using multiple class tokens and an oblique manifold with negative inner product.
result Improves zero-shot classification performance by an average of 6.1%.

iCOS method estimates risk-neutral densities and option prices without model assumptions.

problem Estimating risk-neutral densities and option prices without model assumptions.
method Leverages Fourier-cosine technique using option-implied cosine series coefficients, without model assumptions.
result Effective in extracting information from option prices under various market conditions.

Modified cosine distance improves similarity performance in data with variance and correlation.

problem Limitations of traditional cosine similarity in random variable spaces with variance and correlation.
method Proposed a variance-adjusted cosine distance metric to overcome limitations of traditional cosine similarity.
result Modified cosine distance shows 100% test accuracy in KNN model on the Wisconsin Breast Cancer Dataset.

Improved MoE performance through perturbing cosine router.

problem Representation collapse and parameter redundancy in MoE models.
method Least square estimation of cosine router in MoE, followed by noise addition to improve convergence rates.
result Perturbed cosine router leads to polynomial convergence rates for MoE models.

A new geometric metric identifies true data changes from parametrization artifacts in high-dimensional representations.

problem Quantifying representation drift in high-dimensional data using Euclidean or cosine distances can misattribute changes due to arbitrary parametrizations.
method Introducing the Fubini Study metric to identify representations that differ only by gauge transformations.
result The Fubini Study metric isolates intrinsic evolution by remaining invariant under gauge-induced fluctuations, providing a diagnostic for meaningful structural changes.

Coherent Multiplex analyzes real-time wavelet coherence among multiple signals.

problem Identifying and visualizing coherence among multiple time series.
method Fast spectral similarity based on cosine similarity metrics of Fourier-transformed signals and sparse time-frequency wavelet coherence.
result Scalable real-time system for low-latency inference and monitoring of inter-signal relationships.

This study shows how DDPM can be represented by the OU process.

problem Designing optimal noise schedules for DDPM.
method Formal equivalence between DDPM and OU process, heuristic designs based on Fisher Information.
result Fisher-Information-motivated schedule corresponds to cosine noise schedule.

Researchers establish bounds and continuity of decomposed Möbius energies using cosine formula.

problem Estimating the bounds and continuity of decomposed Möbius energies.
method Using the cosine formula to evaluate upper and lower bounds and modulus of continuity of decomposed energies.
result Affirmative answer to the question of estimating decomposed energies using the cosine formula.

New method linearizes Darboux transformations of discrete curves.

problem Linearizing Darboux transformations of discrete curves.
method Expressing Darboux transformations as parallel sections of discrete connections in quaternionic formalism.
result Closed-form discrete parametrisations of all Darboux transforms and bicycle correspondences.

Geometric approach uses Bäcklund transformations to create integrable discrete analogs of surface nets.

problem Creating integrable discrete analogs of surface nets and conjugate nets.
method Interpreting classical differential geometry results through Bäcklund transformations and applying permutability properties.
result Integrable discrete analogs of asymptotic and conjugate nets are constructed.

QFDA combines machine learning and information theory for image classification.

problem Lack of literature on combining machine learning and information theory.
method Quantized Fisher Discriminant Analysis (QFDA) using a cost function for rate-distortion optimization.
result QFDA achieves at least as good classification accuracy as FDA on quantized images.

We study the dynamics of the discrete bicycle (Darboux, Backlund) transformation of polygons in n-dimensional Euclidean space. This transformation is a discretization of the continuous bicycle transformation, recently studied by Foote, Levi, and Tabachnikov. We prove that the respective monodromy is a Moebius transform…

2012-11-10abs ↗pdf ↗

Derives hyperbolic laws of cosines and sines with fermionic corrections.

problem Deriving hyperbolic laws of cosines and sines with new mathematical corrections.
method Using Minkowski supergeometry, the laws of cosines and sines are derived in the super hyperbolic plane.
result Identical formulae to classical cases with fermionic corrections for cosines and sines.

Cosine similarity can force points to grow in magnitude, causing convergence issues.

problem Cosine similarity loss can lead to convergence issues in deep learning.
method Analyzing under-explored settings and proposing cut-initialization.
result Cosine similarity optimization forces points to grow in magnitude, leading to convergence issues.

This work shows cosine similarity is equivalent to Pearson correlation for word vectors, but not all vectors are suitable for cosine.

problem The use of cosine similarity for semantic textual similarity is often taken for granted, despite its limitations.
method Characterized cases where Pearson correlation is unfit and introduced rank correlation as an alternative.
result Pearson correlation is equivalent to cosine similarity for many word vectors but not all, and rank correlation can improve performance.

We study the rigidity of polyhedral surfaces using variational principle. The action functionals are derived from the cosine laws. The main focus of this paper is on the cosine law for a non-triangular region bounded by three possibly disjoint geodesics. Several of these cosine laws were first discovered and used by Fe…

2007-11-05abs ↗pdf ↗

A new method for discrete data normalizing flows using latent transformations.

problem Challenges in parameterizing bijective transformations for discrete data.
method Predict a distribution over latent transformations to make the marginal likelihood differentiable.
result Discrete-data normalizing flows can be trained using gradient-based learning with unbiased score function estimation.

New Bäcklund transformations for discrete pseudospherical surfaces of revolution are found.

problem Constructing new non-rotational discrete pseudospherical surfaces.
method Explicit parametrizations and Bäcklund transformations for discrete constant negative Gaussian curvature surfaces of revolution.
result Conditions for Bäcklund transformations to preserve periodicity are provided.