20,440 research outputs found
Empirical Evaluation of Contextual Policy Search with a Comparison-based Surrogate Model and Active Covariance Matrix Adaptation
Contextual policy search (CPS) is a class of multi-task reinforcement
learning algorithms that is particularly useful for robotic applications. A
recent state-of-the-art method is Contextual Covariance Matrix Adaptation
Evolution Strategies (C-CMA-ES). It is based on the standard black-box
optimization algorithm CMA-ES. There are two useful extensions of CMA-ES that
we will transfer to C-CMA-ES and evaluate empirically: ACM-ES, which uses a
comparison-based surrogate model, and aCMA-ES, which uses an active update of
the covariance matrix. We will show that improvements with these methods can be
impressive in terms of sample-efficiency, although this is not relevant any
more for the robotic domain.Comment: Supplementary material for poster paper accepted at GECCO 2019;
https://doi.org/10.1145/3319619.332193
Learning Dynamic Robot-to-Human Object Handover from Human Feedback
Object handover is a basic, but essential capability for robots interacting
with humans in many applications, e.g., caring for the elderly and assisting
workers in manufacturing workshops. It appears deceptively simple, as humans
perform object handover almost flawlessly. The success of humans, however,
belies the complexity of object handover as collaborative physical interaction
between two agents with limited communication. This paper presents a learning
algorithm for dynamic object handover, for example, when a robot hands over
water bottles to marathon runners passing by the water station. We formulate
the problem as contextual policy search, in which the robot learns object
handover by interacting with the human. A key challenge here is to learn the
latent reward of the handover task under noisy human feedback. Preliminary
experiments show that the robot learns to hand over a water bottle naturally
and that it adapts to the dynamics of human motion. One challenge for the
future is to combine the model-free learning algorithm with a model-based
planning approach and enable the robot to adapt over human preferences and
object characteristics, such as shape, weight, and surface texture.Comment: Appears in the Proceedings of the International Symposium on Robotics
Research (ISRR) 201
A Maximum-Entropy Partial Parser for Unrestricted Text
This paper describes a partial parser that assigns syntactic structures to
sequences of part-of-speech tags. The program uses the maximum entropy
parameter estimation method, which allows a flexible combination of different
knowledge sources: the hierarchical structure, parts of speech and phrasal
categories. In effect, the parser goes beyond simple bracketing and recognises
even fairly complex structures. We give accuracy figures for different
applications of the parser.Comment: 9 pages, LaTe
Event Organization 101: Understanding Latent Factors of Event Popularity
The problem of understanding people's participation in real-world events has
been a subject of active research and can offer valuable insights for human
behavior analysis and event-related recommendation/advertisement. In this work,
we study the latent factors for determining event popularity using large-scale
datasets collected from the popular Meetup.com EBSN in three major cities
around the world. We have conducted modeling analysis of four contextual
factors (spatial, group, temporal, and semantic), and also developed a
group-based social influence propagation network to model group-specific
influences on events. By combining the Contextual features And Social Influence
NetwOrk, our integrated prediction framework CASINO can capture the diverse
influential factors of event participation and can be used by event organizers
to predict/improve the popularity of their events. Evaluations demonstrate that
our CASINO framework achieves high prediction accuracy with contributions from
all the latent features we capture.Comment: International AAAI Conference on Web and Social Media (ICWSM) 2017
https://www.aaai.org/ocs/index.php/ICWSM/ICWSM17/paper/view/1557
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