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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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3979118157 · Jun 202019922001200920172026
48 results for greedy actions

We consider interactive learning and covering problems, in a setting where actions may incur different costs, depending on the response to the action. We propose a natural greedy algorithm for response-dependent costs. We bound the approximation factor of this greedy algorithm in active learning settings as well as in …

2016-02-23abs ↗pdf ↗

Efficient algorithms identify true hypothesis from many options with minimal actions.

problem Identifying true hypothesis from a large set of options with minimal actions.
method Greedy approximation algorithms for active sequential hypothesis testing.
result First approximation guarantees for ASHT, independent of the number of hypotheses.

A new RL approach learns near-equivalent actions for healthcare decisions.

problem Finding optimal actions in healthcare settings where actions may be near-equivalent.
method Temporal difference learning with a near-greedy heuristic for action selection.
result The proposed algorithm discovers meaningful near-equivalent actions and converges well.

Greedy algorithm nearly outperforms exploration in contextual bandits.

problem Balancing exploration and exploitation in online learning.
method Smoothed analysis of the greedy algorithm in linear contextual bandits.
result Greedy algorithm nearly matches Bayesian regret rate under diversity conditions, with regret at most O(T1/3)O(T^{1/3}).

Greedy policies perform poorly in imperfectly observed contextual bandits.

problem Performance of Greedy policies in bandits with partially observed contexts.
method Analysis of Greedy reinforcement learning policies under imperfectly observed contextual bandits.
result Worst-case regret grows poly-logarithmically with the time horizon and the failure probability.

We discuss the relative merits of optimistic and randomized approaches to exploration in reinforcement learning. Optimistic approaches presented in the literature apply an optimistic boost to the value estimate at each state-action pair and select actions that are greedy with respect to the resulting optimistic value f…

2017-06-13abs ↗pdf ↗

In this paper, we propose an active perception method for recognizing object categories based on the multimodal hierarchical Dirichlet process (MHDP). The MHDP enables a robot to form object categories using multimodal information, e.g., visual, auditory, and haptic information, which can be observed by performing acti…

2015-10-01abs ↗pdf ↗

The paper extends a learning heuristic to high-dimensional contexts, reducing the risk of unusual actions.

problem Sequential learning problems in high dimensions, especially in dynamic pricing and auctions.
method Introducing a conservative εtε_t-greedy rule that limits the adoption of new actions to a focused set of promising actions.
result Reasonable bounds for cumulative regret and improved regret bound for conservative version compared to non-conservative.

The question of how to explore, i.e., take actions with uncertain outcomes to learn about possible future rewards, is a key question in reinforcement learning (RL). Here, we show a surprising result: We show that Q-learning with nonlinear Q-function and no explicit exploration (i.e., a purely greedy policy) can learn s…

2018-05-29abs ↗pdf ↗

DE is a new exploration method that limits resource usage based on expected improvement and surprise.

problem Limited exploration in large action spaces when resources are scarce.
method Delight-gated exploration (DE) that limits exploration actions based on a gate price set by the product of expected improvement and surprise.
result DE outperforms ε\varepsilon-greedy and Thompson Sampling in terms of regret across various bandit and MDP settings.

Proposes a new algorithm for accurate tree-based models with guaranteed recourse actions.

problem Ensuring recourse actions for models optimized for predictive performance.
method Formulates and solves an optimization task to ensure reasonable actions for as many instances as possible, using adversarial training techniques.
result Successfully provided reasonable actions to more instances than baselines without significantly degrading accuracy and computational efficiency.

Regularization-induced exploration improves contextual bandit performance.

problem Complex reward models in real-world contextual bandits are hard to explore effectively.
method Regularization-induced exploration using stochasticity in cross-validation.
result Regularization-induced exploration leads to reliable exploration in large-scale business environments.

New algorithm for combinatorial bandit problems reduces regret.

problem Optimal selection of sets of arms in bandit problems.
method SGB algorithm with optimized exploration of unselected arms.
result Achieves (11/e)(1-1/e)-regret bound of O(n13k23T23log(T)23)\mathcal{O}(n^{\frac{1}{3}} k^{\frac{2}{3}} T^{\frac{2}{3}} \log(T)^{\frac{2}{3}}).

We study adversarial attacks that manipulate the reward signals to control the actions chosen by a stochastic multi-armed bandit algorithm. We propose the first attack against two popular bandit algorithms: εε-greedy and UCB, \emph{without} knowledge of the mean rewards. The attacker is able to spend only logarithmic …

2018-10-29abs ↗pdf ↗

Multi-step greedy policies have been extensively used in model-based reinforcement learning (RL), both when a model of the environment is available (e.g.,~in the game of Go) and when it is learned. In this paper, we explore their benefits in model-free RL, when employed using multi-step dynamic programming algorithms: …

2019-10-07abs ↗pdf ↗

Simple greedy algorithms can excel in multi-objective bandits with multiple good arms.

problem Optimizing multiple objectives in bandits is traditionally harder.
method Introduced greedy algorithms that exploit multiple good arms for multiple objectives.
result Simple greedy algorithms achieve strong performance in multi-objective bandits.

Efficient algorithms for planning in cooperative multi-agent reinforcement learning with combinatorial action spaces.

problem Planning in cooperative multi-agent reinforcement learning with a combinatorial action space.
method Efficient algorithms using local access to a simulator and linear function approximation, with improvements for additive feature decomposition and kernelized settings.
result Polynomial compute and query complexity in relevant problem parameters.

Paper introduces a new analysis framework for stochastic linear bandits.

problem Optimizing decision-making in online experiments with noisy rewards.
method Develops a general analysis framework and algorithms for stochastic linear bandits.
result Introduces new algorithms like SG that improve performance and provide new regret bounds.

Proposes H-UCRL for efficient model-based RL with sublinear regret.

problem Greedy policy exploration in model-based RL ignores epistemic uncertainty.
method Reparameterizes plausible models, hallucinates control, augments input space, solves with greedy planners.
result H-UCRL achieves provably sublinear regret for Gaussian Process models.

Greedy algorithm achieves sublinear regret for various distributions.

problem Efficient performance of greedy algorithms in linear contextual bandit problems.
method Introduced Local Anti-Concentration (LAC) condition to ensure sublinear regret.
result Greedy algorithm achieves O(polylogT)O(\operatorname{poly} \log T) cumulative expected regret.

Exploration is a difficult challenge in reinforcement learning and even recent state-of-the art curiosity-based methods rely on the simple epsilon-greedy strategy to generate novelty. We argue that pure random walks do not succeed to properly expand the exploration area in most environments and propose to replace singl…

2018-07-05abs ↗pdf ↗

Exploration is a difficult challenge in reinforcement learning and is of prime importance in sparse reward environments. However, many of the state of the art deep reinforcement learning algorithms, that rely on epsilon-greedy, fail on these environments. In such cases, empowerment can serve as an intrinsic reward sign…

2018-10-11abs ↗pdf ↗

We present an information-theoretic framework for sequential adaptive compressed sensing, Info-Greedy Sensing, where measurements are chosen to maximize the extracted information conditioned on the previous measurements. We show that the widely used bisection approach is Info-Greedy for a family of kk-sparse signals b…

2014-07-02abs ↗pdf ↗

New distributions allow greedy arm selection in sparse bandit problems.

problem Sparse contextual bandit problem with sparse parameters and feature distributions.
method Introduced new distribution classes and demonstrated that mixtures of these distributions are also greedy-applicable.
result Greedy algorithm applicable to a wider range of arm feature distributions, including those with origin-asymmetric support.

This paper is a follow up to the previous author's paper on convex optimization. In that paper we began the process of adjusting greedy-type algorithms from nonlinear approximation for finding sparse solutions of convex optimization problems. We modified there three the most popular in nonlinear approximation in Banach…

2012-06-02abs ↗pdf ↗

Introduces greedy feature selection for classifier-dependent feature ranking.

problem Feature selection for classification tasks.
method Greedy feature selection, identifying the most important feature at each step based on the selected classifier.
result Theoretical and numerical benefits of greedy feature selection.

An automatic program that generates constant profit from the financial market is lucrative for every market practitioner. Recent advance in deep reinforcement learning provides a framework toward end-to-end training of such trading agent. In this paper, we propose an Markov Decision Process (MDP) model suitable for the…

2018-07-08abs ↗pdf ↗

This paper proposes and evaluates the k-greedy equivalence search algorithm (KES) for learning Bayesian networks (BNs) from complete data. The main characteristic of KES is that it allows a trade-off between greediness and randomness, thus exploring different good local optima. When greediness is set at maximum, KES co…

2012-10-19abs ↗pdf ↗

Reinforcement learning addresses the dilemma between exploration to find profitable actions and exploitation to act according to the best observations already made. Bandit problems are one such class of problems in stateless environments that represent this explore/exploit situation. We propose a learning algorithm for…

2012-02-14abs ↗pdf ↗

Paper analyzes Greedy-GQ for reinforcement learning with Markovian noise.

problem Analyzing Greedy-GQ for reinforcement learning with Markovian noise.
method Develops finite-sample analysis for Greedy-GQ with linear function approximation under Markovian noise.
result Provides theoretical justification for choosing stepsizes for faster convergence.