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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.

168,657 papers · 148 categories

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135270405540 · Jun 202019922001200920172026
48 results for Truncated Samples

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.

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.

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.

In this paper, we develop a general theory of truncated inverse binomial sampling. In this theory, the fixed-size sampling and inverse binomial sampling are accommodated as special cases. In particular, the classical Chernoff-Hoeffding bound is an immediate consequence of the theory. Moreover, we propose a rigorous and…

2019-08-19abs ↗pdf ↗

A new algorithm speeds up elliptical slice sampling for truncated multivariate normals.

problem Efficiently sampling from truncated multivariate normal distributions with linear constraints.
method Adapting elliptical slice sampling to linearly truncated multivariate normals, with an algorithm for ellipse-polytope intersection in O(m log m) time.
result The algorithm enhances numerical stability, speeds up running time, and is easy to parallelize.

Estimates inverse temperature of Ising models with a single sample.

problem Estimating inverse temperature in truncated Ising models with hard constraints.
method Maximizing pseudolikelihood to estimate the inverse temperature.
result An estimator that is nearly O(n)O(n) time and O(Δ3/n)O(Δ^3/\sqrt{n})-consistent.

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 ↗

We study the problem of estimating the parameters of a Gaussian distribution when samples are only shown if they fall in some (unknown) subset SRdS \subseteq \R^d. This core problem in truncated statistics has long history going back to Galton, Lee, Pearson and Fisher. Recent work by Daskalakis et al. (FOCS'18), provide…

2019-08-02abs ↗pdf ↗

We provide an efficient algorithm for the classical problem, going back to Galton, Pearson, and Fisher, of estimating, with arbitrary accuracy the parameters of a multivariate normal distribution from truncated samples. Truncated samples from a dd-variate normal N(μ,Σ){\cal N}(\mathbfμ,\mathbfΣ) means a samples is only re…

2018-09-11abs ↗pdf ↗

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.

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.

Soft Truncation improves diffusion model performance by balancing loss scales across diffusion times.

problem Inverse correlation between density estimation and sample generation in diffusion models.
method Introduces Soft Truncation, a training technique that softens the truncation hyperparameter.
result Soft Truncation achieves state-of-the-art performance on various datasets.

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 ↗

New algorithms estimate parameters of Gaussian and non-Gaussian distributions from truncated samples.

problem Estimating distributional parameters from truncated samples.
method Polynomial time algorithms for exponential families and simple sets.
result Efficient algorithms for estimating parameters of various distributions from truncated samples.

Adaptive truncation improves privacy in online Bayesian estimation.

problem Ensuring privacy in online Bayesian estimation of a static parameter.
method Sequential Monte Carlo, adaptive truncation, Thompson sampling.
result Adaptive truncation reduces privacy-preserving noise, enabling more accurate estimation.

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.

We propose a new framework for Hamiltonian Monte Carlo (HMC) on truncated probability distributions with smooth underlying density functions. Traditional HMC requires computing the gradient of potential function associated with the target distribution, and therefore does not perform its full power on truncated distribu…

2017-09-08abs ↗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 ↗

A new method reduces variance in PG methods for RL, improving efficiency and convergence.

problem Improving sample efficiency and convergence of policy gradient methods in reinforcement learning.
method Proposes a gradient truncation mechanism and designs TSIVR-PG method to maximize rewards and utility.
result Shows sample complexity of TSIVR-PG to find ε-stationary policy and global ε-optimal policy.

Dirichlet process mixture models (DPMM) are a cornerstone of Bayesian non-parametrics. While these models free from choosing the number of components a-priori, computationally attractive variational inference often reintroduces the need to do so, via a truncation on the variational distribution. In this paper we presen…

2017-01-13abs ↗pdf ↗

Decoding strategies often exclude human-like tokens, creating a detectable gap in generated text.

problem Decoding strategies exclude contextually appropriate but statistically rare tokens, creating a detectable gap in generated text.
method Analysis of 1.8 million texts across 8 language models, 5 decoding strategies, and 53 hyperparameter configurations.
result 8-18% of human-selected tokens fall outside typical truncation boundaries, indicating a detectable gap.

Fractured Sampling improves LLM reasoning efficiency by truncating CoT trajectories.

problem Efficiently scaling reasoning in large language models with limited tokens.
method Integrating truncated Chain-of-Thought (CoT) with Fractured Sampling across multiple dimensions.
result Fractured Sampling achieves superior accuracy-cost trade-offs compared to full CoT.

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.

TKRR improves KRR performance by aligning target functions with kernels.

problem Improving kernel ridge regression performance through target alignment.
method Focuses on truncated kernel ridge regression (TKRR) with an additional spectral truncation parameter.
result TKRR can achieve faster rates than full KRR, reaching parametric rates.

The positivity assumption, or the experimental treatment assignment (ETA) assumption, is important for identifiability in causal inference. Even if the positivity assumption holds, practical violations of this assumption may jeopardize the finite sample performance of the causal estimator. One of the consequences of pr…

2017-07-18abs ↗pdf ↗

Computing partition functions, the normalizing constants of probability distributions, is often hard. Variants of importance sampling give unbiased estimates of a normalizer Z, however, unbiased estimates of the reciprocal 1/Z are harder to obtain. Unbiased estimates of 1/Z allow Markov chain Monte Carlo sampling of "d…

2016-10-15abs ↗pdf ↗

This paper addresses challenges in flexibly modeling multimodal data that lie on constrained spaces. Such data are commonly found in spatial applications, such as climatology and criminology, where measurements are restricted to a geographical area. Other settings include domains where unsuitable recordings are discard…

2018-09-24abs ↗pdf ↗

New algorithm improves inference for flexible models with infinite latent features.

problem Inference for models with infinite latent features is computationally challenging and limiting.
method Adaptive slice sampling for posterior inference with general completely random measures.
result Higher effective sample size and predictive performance compared to existing methods.

Optimality of TS with noninformative priors proven for Pareto model.

problem Optimality of Thompson Sampling with noninformative priors for Pareto bandits.
method Proved optimality of TS with certain probability matching priors, showed suboptimality with others, and found effectiveness of truncation procedures.
result TS with certain probability matching priors achieves optimal regret bound for Pareto model.

New method uses SDEs for accurate non-uniformly sampled time series analysis.

problem Characterizing non-uniformly sampled time series with high accuracy.
method Stochastic Differential Equations (SDEs) for modeling, incremental estimation, and model truncation.
result Increased accuracy in characterizing non-uniformly sampled time series.

New method reduces sample complexity for robust reinforcement learning.

problem Finite sample analysis in robust reinforcement learning.
method Stochastic approximation framework with controlled bias, using MLMC techniques and geometric truncation.
result Order-optimal sample complexity of ildeO(ε2) ilde{\mathcal{O}}(ε^{-2}) for robust policy evaluation.

Paper proposes robust methods for estimating optimal treatment rules with censored survival data.

problem Estimating optimal treatment rules for censored survival data.
method Developed two robust criteria and a sampling-based difference-of-convex algorithm for learning optimal treatment rules.
result Proposed methods show improved performance compared to existing methods in simulations and real data.

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 ↗

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.

Motivated by a recent result of Daskalakis et al. 2018, we analyze the population version of Expectation-Maximization (EM) algorithm for the case of \textit{truncated} mixtures of two Gaussians. Truncated samples from a dd-dimensional mixture of two Gaussians $\frac{1}{2} \mathcal{N}(\vecμ, \vecΣ)+ \frac{1}{2} \mathca…

2019-02-19abs ↗pdf ↗