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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.

168,786 papers · 148 categories

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4691137182 · Jun 202019922001200920172026
48 results for instance difficulty

Algorithm extsc{Pedel} learns near-optimal policies efficiently on specific problems.

problem Learning near-optimal policies in linear MDPs with minimal samples.
method Online experiment design to focus exploration on relevant directions.
result Achieves instance-dependent complexity, outperforming minimax-optimal algorithms.

Mathematical Reinforcement Learning faces a 'Two-Hump' problem due to sparse rewards and a scarcity of intermediate 'hard-but-solvable' instances.

problem Mathematical search problems in Reinforcement Learning
method Novel data generation techniques and algorithmic enhancements
result Substantial performance improvements over previous baselines

New CTRL algorithm adapts to varying problem difficulty.

problem Adapting to varying levels of problem difficulty in CTRL.
method MLE with a general function approximator, estimating state marginal density.
result Regret bound scales with reward variance and measurement resolution, independent of measurement strategy.

Paper tackles gene mutation prediction for HCC using multi-instance multi-label learning.

problem Gene mutation prediction in hepatocellular carcinoma for personalized treatments.
method Multi-instance multi-label learning with oversampling for data imbalance.
result Proposed approach shows superiority in gene mutation prediction.

New method estimates optimal Q-values with better accuracy for specific problems.

problem Estimating optimal Q-values in reinforcement learning is difficult and varies by problem instance.
method Local minimax framework and variance-reduced Q-learning.
result Sharp lower bounds on estimation accuracy for Q-learning.

This work embeds annotations into a multidimensional space to measure classification difficulty.

problem Uncertainty in machine learning models during annotation phase.
method Develops a Bayesian Dirichlet-Multinomial framework to embed annotations and uses stochastic Expectation Maximization with MCMC.
result Embeddings reflect semantic similarities of original classes, aiding in measuring classification difficulty.

Learning shrinks hard tail, improving inference performance.

problem Improving inference performance in neural networks.
method Latent Instance Difficulty (LID) model analyzing fine-tuning of neural networks.
result Training-dependent inference scaling, with βexteffβ_ ext{eff} growing with sample size before saturating.

The research proposes a stopping rule for reinforcement learning algorithms based on instance-dependent confidence.

problem Dramatic variation in convergence rates of reinforcement learning algorithms due to problem structure.
method Develops instance-dependent confidence regions and a data-dependent stopping rule for MDP policy evaluation and optimal value estimation.
result Proposes a stopping rule that adapts to the instance-specific difficulty of the problem, allowing for early termination.

Gradient descent with specific initialization and step size achieves optimal sparse signal recovery.

problem Reconstructing a sparse signal from underdetermined linear measurements.
method Gradient descent with specific initialization, step size, and stopping time.
result Achieves the minimax rate with poly-logarithmic factors and adapts to instance difficulty.

Algorithm generates adaptive confidence sets for instance segmentation with guaranteed coverage.

problem Uncalibrated predictions and lack of uncertainty quantification in instance segmentation models.
method Conformal prediction algorithm to generate adaptive confidence sets with provable guarantees.
result Empirically, prediction sets vary in size based on query difficulty and attain target coverage, outperforming baselines.

Item Response Theory (IRT) aims to assess latent abilities of respondents based on the correctness of their answers in aptitude test items with different difficulty levels. In this paper, we propose the β3β^3-IRT model, which models continuous responses and can generate a much enriched family of Item Characteristic Cur…

2019-03-10abs ↗pdf ↗

The study compares uniform-price and discriminatory auctions in terms of learning difficulty.

problem Comparing the learning difficulty of uniform-price and discriminatory multi-unit auctions.
method Characterization of learning difficulty through regret minimization in both full-information and bandit feedback settings.
result Regret scales similarly for both auction formats under full-information, but uniform-price auctions can achieve faster learning rates.

New algorithms improve contextual bandit performance by adapting to problem difficulty.

problem Improving contextual bandit performance on problems with varying difficulty.
method Introducing complexity measures and oracle-efficient algorithms.
result Achieves optimal instance-dependent regret bounds for rich policy classes.

Most methods for decision-theoretic online learning are based on the Hedge algorithm, which takes a parameter called the learning rate. In most previous analyses the learning rate was carefully tuned to obtain optimal worst-case performance, leading to suboptimal performance on easy instances, for example when there ex…

2011-10-28abs ↗pdf ↗

Adaptive compute allocation improves model performance by prioritizing harder queries.

problem Inefficiency in allocating test-time compute uniformly across all queries.
method Formulated as a bandit learning problem, proposed adaptive algorithms that estimate query difficulty and allocate compute accordingly.
result Achieved up to 15.29% relative performance improvement on various benchmarks.

This paper poses some basic questions about instances (hard to find) of a special problem in 3-manifold topology. "Important though the general concepts and propositions may be with the modern industrious passion for axiomatizing and generalizing has presented us...nevertheless I am convinced that the special problems …

2013-04-18abs ↗pdf ↗

New research shows that binary classification can be done with noisy data, but only if there are clean samples available.

problem Learning binary classification with instance and label dependent label noise.
method Theoretical analysis and empirical risk minimization.
result Empirical risk minimization achieves the optimal excess risk bound without additional assumptions.

Proposes an IRT-based ensemble method to improve machine learning accuracy.

problem Improving the accuracy of machine learning models, especially for hard-to-classify instances.
method Introduces Item Response Theory (IRT) to evaluate sample difficulty and classifier ability, creating three models with different assumptions.
result The proposed IRT ensemble model outperforms other methods on 19 datasets.

Adaptive algorithms minimize regret in matching markets with contextual arm preferences.

problem Minimizing regret in matching markets with context-dependent player utilities.
method Developed adaptive algorithms for stochastic and adversarial contexts, providing upper and lower bounds.
result Achieved sublinear regret bounds for both stochastic and adversarial contexts.

Study task-guided exploration in linear dynamical systems, improving sample complexity.

problem Efficiently learning about an environment to complete a specific task.
method Proposed a computationally efficient experiment-design based exploration algorithm.
result Optimally explores the environment, collecting precise information needed to complete the task.

This paper analyzes the difficulty of unsupervised domain adaptation using information theory.

problem The challenge of unsupervised domain adaptation under covariate shift.
method Formulates the problem using a distribution π in the ground-truth triples (p, q, f), defines optimal learner performance, and introduces PTLU for quantifying difficulty.
result Characterizes the optimal learner and introduces PTLU as a measure of UDA difficulty.

We propose SPARFA-Trace, a new machine learning-based framework for time-varying learning and content analytics for education applications. We develop a novel message passing-based, blind, approximate Kalman filter for sparse factor analysis (SPARFA), that jointly (i) traces learner concept knowledge over time, (ii) an…

2013-12-19abs ↗pdf ↗

Active learning method reduces labeling cost for regression models with aggregated data.

problem Reducing labeling cost for training regression models with aggregated data.
method Sequentially selects sets to be labeled using mutual information quantifying model parameter uncertainty.
result Achieves better predictive performance with fewer labeled sets.

A new approach for instance-optimal learning that bypasses impossibility results.

problem Impossibility of achieving marginal-by-marginal guarantees for all marginals.
method Introduces relatively smart learning, which requires competition only with certifiable semi-supervised guarantees.
result One-Inclusion Graph learner is relatively smart up to squaring the sample complexity.

Perceptrons are neuronal devices capable of fully discriminating linearly separable classes. Although straightforward to implement and train, their applicability is usually hindered by non-trivial requirements imposed by real-world classification problems. Therefore, several approaches, such as kernel perceptrons, have…

2016-03-22abs ↗pdf ↗

New algorithms optimize private convex optimization with faster rates for functions with κ-growth.

problem Optimizing private convex functions with varying difficulty and growth conditions.
method Adapts inverse sensitivity mechanism and localization techniques to achieve faster rates without knowing growth constant.
result Achieves faster privacy rates (d/nε)fracκκ1({\sqrt{d}}/{n\varepsilon})^{ fracκ{κ- 1}} for functions with κ-growth.

Generates synthetic data for benchmarking unsupervised outlier detection.

problem Difficulty in benchmarking unsupervised outlier detection due to rare and varied outliers in real data.
method Proposes a generic process to generate synthetic data with insightful characteristics.
result Demonstrates practicality of the generic process through a benchmark with state-of-the-art detection methods.

The paper tackles fair sequential decision making with biased linear bandit feedback.

problem Fair sequential decision making with biased linear bandit feedback.
method Phased elimination algorithm to correct unfair evaluations, establishing upper bounds on regret.
result The worst-case regret is smaller than O(κ1/3log(T)1/3T2/3)\mathcal{O}(κ_*^{1/3}\log(T)^{1/3}T^{2/3}).