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Wataru Hashimoto

6 accepted papers

2025

Decoding Uncertainty: The Impact of Decoding Strategies for Uncertainty Estimation in Large Language Models

EMNLP 2025

Decoding strategies manipulate the probability distribution underlying the output of a language model and can therefore affect both generation quality and its uncertainty. In this study, we investigate the impact of decoding strategies on uncertainty estimation in Large Language Models (LLMs). Our e

2025

Efficient Nearest Neighbor based Uncertainty Estimation for Natural Language Processing Tasks

NAACL 2025findings

Trustworthiness in model predictions is crucial for safety-critical applications in the real world. However, deep neural networks often suffer from the issues of uncertainty estimation, such as miscalibration. In this study, we propose k-Nearest Neighbor Uncertainty Estimation (kNN-UE), which is a n…

Cited by 0SourcePDFScholar
2024

Are Data Augmentation Methods in Named Entity Recognition Applicable for Uncertainty Estimation?

EMNLP 2024main

This work investigates the impact of data augmentation on confidence calibration and uncertainty estimation in Named Entity Recognition (NER) tasks. For the future advance of NER in safety-critical fields like healthcare and finance, it is essential to achieve accurate predictions with calibrated co…

2024

Long-Term Safe Reinforcement Learning with Binary Feedback

AAAI 2024technical

Safety is an indispensable requirement for applying reinforcement learning (RL) to real problems. Although there has been a surge of safe RL algorithms proposed in recent years, most existing work typically 1) relies on receiving numeric safety feedback; 2) does not guarantee safety during the learn…

Cited by 3SourcePDFScholar
2023

Safe Exploration in Reinforcement Learning: A Generalized Formulation and Algorithms

NeurIPS 2023poster

Safe exploration is essential for the practical use of reinforcement learning (RL) in many real-world scenarios. In this paper, we present a generalized safe exploration (GSE) problem as a unified formulation of common safe exploration problems. We then propose a solution of the GSE problem in the f…

Cited by 13SourcePDFScholar
2022

STL2vec: Signal Temporal Logic Embeddings for Control Synthesis With Recurrent Neural Networks

RA-L 2022

In this letter, a method for learning a recurrent neural network (RNN) controller that maximizes the robustness of signal temporal logic (STL) specifications is presented. In contrast to previous methods, we consider synthesizing the RNN controller for which the user is able to select an STL specifi

Cited by 22SourceScholar