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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.

168,695 papers · 148 categories

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48 results for left truncated data

Paper estimates spectral risk measures for insurance data with truncated and censored data.

problem Estimating spectral risk measures for insurance data with left truncation and right censoring.
method Proposes a non-parametric estimator using product limit estimator and establishes asymptotic normality.
result Proposed estimator outperforms existing methods for small k and small sample sizes.

Bayesian method estimates LTLL distribution parameters for time-to-event data.

problem Parameter estimation for time-to-event data with left truncation.
method Bayesian inference using Metropolis-Hastings algorithm.
result Bayesian estimation provides more stable and reliable parameter estimates.

New method estimates treatment effects over time for survival data, improving accuracy and smoothness.

problem Estimating treatment effects over time for survival data with left truncation and right censoring.
method surv-iTMLE, a targeted learning procedure for estimating conditional survival probabilities.
result surv-iTMLE outperforms existing methods in bias and smoothness of time-varying effect estimates.

This paper gives quantitative global estimates between a time dependent flow on a Riemannian manifold (M)\left( M\right) and the flow of a vector field constructed by truncating the formal Magnus expansion for the logarithm of the flow. As a corollary, we also find quantitative estimates between the composition of the …

2018-10-04abs ↗pdf ↗

A new method prices time-to-event cash flows using survival analysis.

problem Pricing insurance investment portfolios with time-to-event cash flows.
method Discrete-time survival analysis framework, hazard rate estimators, asymptotic multivariate normality.
result Pricing model yields estimates closer to actual cash flows than non-random models.

The paper estimates common mean of entangled Gaussians with bounded variances.

problem Estimating common mean of entangled Gaussians with bounded variances.
method Iteratively averaging truncated samples.
result Achieves error $O \left(\frac{\sqrt{n\ln n}}{m} ight)$ with high probability when m=Ω(nlnn)m=Ω(\sqrt{n\ln n}).

We show that given an estimate A^\widehat{A} that is close to a general high-rank positive semi-definite (PSD) matrix AA in spectral norm (i.e., A^A2δ\|\widehat{A}-A\|_2 \leq δ), the simple truncated SVD of A^\widehat{A} produces a multiplicative approximation of AA in Frobenius norm. This observation leads to many inte…

2017-02-22abs ↗pdf ↗

Paper establishes tight lower bounds for minimizing certain smooth and convex functions.

problem Minimizing high-order Hölder smooth and uniformly convex functions.
method Analyzes two asymmetric cases of q>p+νq > p + ν and q<p+νq < p + ν using worst-case oracle complexities.
result Establishes worst-case oracle complexities for reaching an ε-approximate solution.

Non-negative matrix factorization (NMF) minimizes the Euclidean distance between the data matrix and its low rank approximation, and it fails when applied to corrupted data because the loss function is sensitive to outliers. In this paper, we propose a Truncated CauchyNMF loss that handle outliers by truncating large e…

2019-06-02abs ↗pdf ↗

Score matching method improves density estimation for truncated data on manifolds.

problem Density estimation for truncated data on manifolds with intractable normalising constant.
method Truncated score matching extended to Riemannian manifolds with boundary.
result Score matching estimator approximates true parameter values with low error.

Proposes a method to handle sparse multiway count data with false zeros using zero-truncated Poisson regression.

problem Handling sparse multiway count data corrupted by false zeros.
method Zero-truncated Poisson regression with tensor completion.
result Accurate estimation of multiway count data from approximately IR2log22(I)IR^2\log_2^2(I) non-zero counts.

The paper investigates the convergence of Vendi scores under finite samples and introduces a truncated version for better performance.

problem The Vendi score's convergence is hindered by computational limitations when using large sample sizes.
method The authors introduce the t-truncated Vendi score to address this issue by truncating the eigenspectrum of the kernel matrix.
result The t-truncated Vendi score converges to its asymptotic limit with a smaller number of samples, improving upon the standard Vendi score.

Paper proposes robust estimators for heavy-tailed data with infinite variance.

problem Developing robust estimators for heavy-tailed data with infinite variance.
method Proposes two robust estimators: ridge log-truncated M-estimator and elastic net log-truncated M-estimator.
result Demonstrates robustness of log-truncated estimations over standard estimations through simulations and real data analysis.

The problem of an arbitrary truncated Levy flight description using the method of cumulant approach has been solved. The set of cumulants of the truncated Levy distribution given the assumption of arbitrary truncation has been found. The influence of truncation shape on the truncated Levy flight properties in the Gauss…

2010-06-12abs ↗pdf ↗

We study inference and learning based on a sparse coding model with `spike-and-slab' prior. As in standard sparse coding, the model used assumes independent latent sources that linearly combine to generate data points. However, instead of using a standard sparse prior such as a Laplace distribution, we study the applic…

2012-11-15abs ↗pdf ↗

Efficiently estimate Boolean product distribution parameters from truncated samples.

problem Estimating parameters of Boolean product distributions from truncated samples.
method Introducing fatness of truncation set, using membership queries, and adapting Stochastic Gradient Descent.
result Efficiently learn Boolean product distributions from truncated samples with small sample complexity.

In the paper "On Truncated Variation of Brownian Motion with Drift" (Bull. Pol. Acad. Sci. Math. 56 (2008), no.4, 267 - 281) we defined truncated variation of Brownian motion with drift, Wt=Bt+μt,t0,W_t = B_t + μt, t\geq 0, where (Bt)(B_t) is a standard Brownian motion. Truncated variation differs from regular variation by neglect…

2009-12-23abs ↗pdf ↗

As in standard linear regression, in truncated linear regression, we are given access to observations (Ai,yi)i(A_i, y_i)_i whose dependent variable equals yi=AiTx+ηiy_i= A_i^{\rm T} \cdot x^* + η_i, where xx^* is some fixed unknown vector of interest and ηiη_i is independent noise; except we are only given an observation if its dep…

2020-07-29abs ↗pdf ↗

Learning with a {\it convex loss} function has been a dominating paradigm for many years. It remains an interesting question how non-convex loss functions help improve the generalization of learning with broad applicability. In this paper, we study a family of objective functions formed by truncating traditional loss f…

2018-05-21abs ↗pdf ↗

Optimal algorithm learns Gaussian under halfspace truncation with minimal samples.

problem Learning a Gaussian distribution truncated to an unknown halfspace.
method Efficient algorithm using n=ildeO(d2/ε2)n = ilde{O}(d^2/\varepsilon^2) samples and runtime dominated by empirical covariance matrix computation.
result Optimal sample and time complexity bounds for learning a Gaussian under halfspace truncation.

Stochastic gradient descent (SGD) is commonly used for optimization in large-scale machine learning problems. Langford et al. (2009) introduce a sparse online learning method to induce sparsity via truncated gradient. With high-dimensional sparse data, however, the method suffers from slow convergence and high variance…

2016-04-21abs ↗pdf ↗

Combines ML and DA to infer unresolved scale parametrisation from noisy data.

problem Training ML-based parametrisations from realistic, noisy and sparse observations.
method Two-step process: DA for state estimation, ML for model error prediction.
result Hybrid model produces better forecasts and attractor representation.

We develop a scale-invariant truncated Lévy (STL) process to describe physical systems characterized by correlated stochastic variables. The STL process exhibits Lévy stability for the probability density, and hence shows scaling properties (as observed in empirical data); it has the advantage that all moments are fini…

1999-06-25abs ↗pdf ↗

Paper proposes approximate Stein classes for efficient truncated density estimation.

problem Difficulties in estimating truncated density models due to intractable normalising constants and boundary conditions.
method Adapts score matching to solve the problem, introduces approximate Stein classes and a novel discrepancy measure, TKSD.
result TKSD does not require a fixed weighting function and can be evaluated using only boundary samples, leading to improved accuracy.

Derives equations for deep learning biases and weights, showing data complexity reduction.

problem Understanding interpretability in supervised learning.
method Gradient flow equations and dynamical truncation of training data.
result Data complexity reduction at an exponential rate with training.

Kernel ridge regression (KRR) is a well-known and popular nonparametric regression approach with many desirable properties, including minimax rate-optimality in estimating functions that belong to common reproducing kernel Hilbert spaces (RKHS). The approach, however, is computationally intensive for large data sets, d…

2019-06-14abs ↗pdf ↗

In recent studies the truncated Levy process (TLP) has been shown to be very promising for the modeling of financial dynamics. In contrast to the Levy process, the TLP has finite moments and can account for both the previously observed excess kurtosis at short timescales, along with the slow convergence to Gaussian at …

1997-10-20abs ↗pdf ↗

The paper analyzes how random perturbations affect RSVD and its applications.

problem Analyzing the impact of random perturbations on RSVD.
method Derives bounds for distances between exact and approximated singular vectors using RSVD.
result Established nearly-optimal convergence rates and asymptotic normality for RSVD in various inference problems.

New kernels capture both local and non-local interactions efficiently.

problem Designing kernels that capture both local and non-local interactions while remaining computationally tractable.
method Spectral truncation kernels based on CC^*-algebra.
result Spectral truncation kernels induce interactions across the data function domain and reduce computational cost.

Study identifies and analyzes three types of errors in learning Fourier operators.

problem Statistical, discretization, and truncation errors in learning Fourier operators.
method Analysis of a Discrete Fourier Transform (DFT) based least squares estimator.
result Established upper and lower bounds on statistical, discretization, and truncation errors.

The method approximates stationary distributions of Markov models by truncating irrelevant states.

problem Computing the stationary distribution of complex Markov models is computationally challenging.
method A state-space lumping scheme that aggregates states in a grid structure, iteratively refining the state-space.
result The method provides a well-justified finite-state projection tailored to the stationary behavior of Markov models.