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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.

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192383575766 · Jun 202019922001200920172026
48 results for truncated importance sampling

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 ↗

IMPACT improves RL training speed without sacrificing sample efficiency.

problem Limited sample efficiency in scalable RL architectures.
method Proposes IMPACT, extending IMPALA with target networks, circular buffers, and truncated importance sampling.
result IMPACT achieves higher rewards and significantly reduces training time compared to IMPALA.

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 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 ↗

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.

RANDomized-exploration policy Optimization via Multiple Importance Sampling with Truncation (RANDOMIST) for PO with mediator feedback.

problem Policy Optimization in continuous control tasks.
method RANDomized-exploration policy Optimization via Multiple Importance Sampling with Truncation (RANDOMIST) for regret minimization in PO.
result Achieving constant regret under certain circumstances in PO with mediator feedback.

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.

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 Monte Carlo methods are recent variance reduction techniques. In this work, we propose a mathematical setting which greatly relaxes the assumptions needed by for the adaptive importance sampling techniques presented by Vazquez-Abad and Dufresne, Fu and Su, and Arouna. We establish the convergence and asymptoti…

2010-01-20abs ↗pdf ↗

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.

New loss function handles uncertain constraints in CSLO problems.

problem Handling uncertain inequality constraints in CSLO with machine learning predictions.
method Introduces SPO-RC loss and SPO-RC+ surrogate, trains on truncated datasets, corrects bias.
result SPO-RC+ effectively manages constraint uncertainty and improves performance.

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 ↗

Energy-based models (EBMs) are powerful probabilistic models, but suffer from intractable sampling and density evaluation due to the partition function. As a result, inference in EBMs relies on approximate sampling algorithms, leading to a mismatch between the model and inference. Motivated by this, we consider the sam…

2019-10-31abs ↗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.

SUMO provides unbiased log marginal likelihood estimation for latent variable models.

problem Biased estimates of log marginal likelihood in latent variable models.
method Randomized truncation of infinite series for unbiased estimation.
result Models trained with SUMO give better test-set likelihoods than standard methods.

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 ↗

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.

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 ↗

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.