English
Related papers

Related papers: The problem with DDPG: understanding failures in d…

200 papers

Reinforcement learning agents learn from rewards, but humans can uniquely assign value to novel, abstract outcomes in a goal-dependent manner. However, this flexibility is cognitively costly, making learning less efficient. Here, we propose…

Neurons and Cognition · Quantitative Biology 2025-09-11 Gaia Molinaro , Anne G. E. Collins

Greedy algorithms are central to sparse approximation and stage-wise learning methods such as matching pursuit and boosting. It is known that the Power-Relaxed Greedy Algorithm with step sizes $m^{-\alpha}$ may fail to converge when…

Machine Learning · Computer Science 2026-03-10 Pablo M. Berná

Reinforcement learning (RL) can align language models with non-differentiable reward signals, such as human preferences. However, a major challenge arises from the sparsity of these reward signals - typically, there is only a single reward…

Computation and Language · Computer Science 2024-02-20 Meng Cao , Lei Shu , Lei Yu , Yun Zhu , Nevan Wichers , Yinxiao Liu , Lei Meng

Learning a reward function from demonstrations suffers from low sample-efficiency. Even with abundant data, current inverse reinforcement learning methods that focus on learning from a single environment can fail to handle slight changes in…

Machine Learning · Computer Science 2024-05-15 Thomas Kleine Buening , Victor Villin , Christos Dimitrakakis

Reinforcement learning (RL) plays a crucial role in shaping the behavior of large language and reasoning models (LLMs/LRMs). However, it often produces brittle and unstable policies, leading to critical failures such as spurious reasoning,…

Artificial Intelligence · Computer Science 2025-07-29 Xingcheng Xu

Deep Reinforcement Learning (DRL) has been extensively used to address portfolio optimization problems. The DRL agents acquire knowledge and make decisions through unsupervised interactions with their environment without requiring explicit…

Machine Learning · Computer Science 2025-01-14 Ruoyu Sun , Yue Xi , Angelos Stefanidis , Zhengyong Jiang , Jionglong Su

One of the most challenging aspects of real-world reinforcement learning (RL) is the multitude of unpredictable and ever-changing distractions that could divert an agent from what was tasked to do in its training environment. While an agent…

Machine Learning · Computer Science 2020-11-17 Cristian Bodnar , Karol Hausman , Gabriel Dulac-Arnold , Rico Jonschkowski

Learning with sparse rewards remains a significant challenge in reinforcement learning (RL), especially when the aim is to train a policy capable of achieving multiple different goals. To date, the most successful approaches for dealing…

Machine Learning · Computer Science 2020-06-02 Henry Charlesworth , Giovanni Montana

Policy gradient algorithms have proven to be successful in diverse decision making and control tasks. However, these methods suffer from high sample complexity and instability issues. In this paper, we address these challenges by providing…

Machine Learning · Computer Science 2021-03-17 Yannis Flet-Berliac , Reda Ouhamma , Odalric-Ambrym Maillard , Philippe Preux

Multiagent reinforcement learning (MARL) is commonly considered to suffer from non-stationary environments and exponentially increasing policy space. It would be even more challenging when rewards are sparse and delayed over long…

Exploration in environments with sparse rewards has been a persistent problem in reinforcement learning (RL). Many tasks are natural to specify with a sparse reward, and manually shaping a reward function can result in suboptimal…

Machine Learning · Computer Science 2018-02-27 Ashvin Nair , Bob McGrew , Marcin Andrychowicz , Wojciech Zaremba , Pieter Abbeel

Recent research has turned to Reinforcement Learning (RL) to solve challenging decision problems, as an alternative to hand-tuned heuristics. RL can learn good policies without the need for modeling the environment's dynamics. Despite this…

Machine Learning · Computer Science 2023-01-30 Pouya Hamadanian , Malte Schwarzkopf , Siddartha Sen , Mohammad Alizadeh

Reinforcement learning (RL) is one of the active fields in machine learning, demonstrating remarkable potential in tackling real-world challenges. Despite its promising prospects, this methodology has encountered with issues and challenges,…

Machine Learning · Computer Science 2024-11-21 Alireza Rashidi Laleh , Majid Nili Ahmadabadi

Goal-conditioned reinforcement learning (GCRL), related to a set of complex RL problems, trains an agent to achieve different goals under particular scenarios. Compared to the standard RL solutions that learn a policy solely depending on…

Artificial Intelligence · Computer Science 2022-09-05 Minghuan Liu , Menghui Zhu , Weinan Zhang

While deep reinforcement learning techniques have led to agents that are successfully able to learn to perform a number of tasks that had been previously unlearnable, these techniques are still susceptible to the longstanding problem of…

Multimedia · Computer Science 2019-06-07 Nicholas Waytowich , Sean L. Barton , Vernon Lawhern , Ethan Stump , Garrett Warnell

This paper seeks to establish a framework for directing a society of simple, specialized, self-interested agents to solve what traditionally are posed as monolithic single-agent sequential decision problems. What makes it challenging to use…

Machine Learning · Computer Science 2020-08-17 Michael Chang , Sidhant Kaushik , S. Matthew Weinberg , Thomas L. Griffiths , Sergey Levine

Deep reinforcement learning has obtained significant breakthroughs in recent years. Most methods in deep-RL achieve good results via the maximization of the reward signal provided by the environment, typically in the form of discounted…

Machine Learning · Computer Science 2018-09-10 Yubin Deng , Ke Yu , Dahua Lin , Xiaoou Tang , Chen Change Loy

One obstacle to applying reinforcement learning algorithms to real-world problems is the lack of suitable reward functions. Designing such reward functions is difficult in part because the user only has an implicit understanding of the task…

Machine Learning · Computer Science 2018-11-20 Jan Leike , David Krueger , Tom Everitt , Miljan Martic , Vishal Maini , Shane Legg

We propose an algorithm for tabular episodic reinforcement learning with constraints. We provide a modular analysis with strong theoretical guarantees for settings with concave rewards and convex constraints, and for settings with hard…

This paper tackles the challenge of learning non-Markovian optimal execution strategies in dynamic financial markets. We introduce a novel actor-critic algorithm based on Deep Deterministic Policy Gradient (DDPG) to address this issue, with…

Machine Learning · Computer Science 2024-10-18 Alessandro Micheli , Mélodie Monod