837 research outputs found
A Stochastic Hybrid Framework for Driver Behavior Modeling Based on Hierarchical Dirichlet Process
Scalability is one of the major issues for real-world Vehicle-to-Vehicle
network realization. To tackle this challenge, a stochastic hybrid modeling
framework based on a non-parametric Bayesian inference method, i.e.,
hierarchical Dirichlet process (HDP), is investigated in this paper. This
framework is able to jointly model driver/vehicle behavior through forecasting
the vehicle dynamical time-series. This modeling framework could be merged with
the notion of model-based information networking, which is recently proposed in
the vehicular literature, to overcome the scalability challenges in dense
vehicular networks via broadcasting the behavioral models instead of raw
information dissemination. This modeling approach has been applied on several
scenarios from the realistic Safety Pilot Model Deployment (SPMD) driving data
set and the results show a higher performance of this model in comparison with
the zero-hold method as the baseline.Comment: This is the accepted version of the paper in 2018 IEEE 88th Vehicular
Technology Conference (VTC2018-Fall) (references added, title and abstract
modified
Dirichlet belief networks for topic structure learning
Recently, considerable research effort has been devoted to developing deep
architectures for topic models to learn topic structures. Although several deep
models have been proposed to learn better topic proportions of documents, how
to leverage the benefits of deep structures for learning word distributions of
topics has not yet been rigorously studied. Here we propose a new multi-layer
generative process on word distributions of topics, where each layer consists
of a set of topics and each topic is drawn from a mixture of the topics of the
layer above. As the topics in all layers can be directly interpreted by words,
the proposed model is able to discover interpretable topic hierarchies. As a
self-contained module, our model can be flexibly adapted to different kinds of
topic models to improve their modelling accuracy and interpretability.
Extensive experiments on text corpora demonstrate the advantages of the
proposed model.Comment: accepted in NIPS 201
Spatiotemporal Learning of Multivehicle Interaction Patterns in Lane-Change Scenarios
Interpretation of common-yet-challenging interaction scenarios can benefit
well-founded decisions for autonomous vehicles. Previous research achieved this
using their prior knowledge of specific scenarios with predefined models,
limiting their adaptive capabilities. This paper describes a Bayesian
nonparametric approach that leverages continuous (i.e., Gaussian processes) and
discrete (i.e., Dirichlet processes) stochastic processes to reveal underlying
interaction patterns of the ego vehicle with other nearby vehicles. Our model
relaxes dependency on the number of surrounding vehicles by developing an
acceleration-sensitive velocity field based on Gaussian processes. The
experiment results demonstrate that the velocity field can represent the
spatial interactions between the ego vehicle and its surroundings. Then, a
discrete Bayesian nonparametric model, integrating Dirichlet processes and
hidden Markov models, is developed to learn the interaction patterns over the
temporal space by segmenting and clustering the sequential interaction data
into interpretable granular patterns automatically. We then evaluate our
approach in the highway lane-change scenarios using the highD dataset collected
from real-world settings. Results demonstrate that our proposed Bayesian
nonparametric approach provides an insight into the complicated lane-change
interactions of the ego vehicle with multiple surrounding traffic participants
based on the interpretable interaction patterns and their transition properties
in temporal relationships. Our proposed approach sheds light on efficiently
analyzing other kinds of multi-agent interactions, such as vehicle-pedestrian
interactions. View the demos via https://youtu.be/z_vf9UHtdAM.Comment: for the supplements, see
https://chengyuan-zhang.github.io/Multivehicle-Interaction
Symbol Emergence in Robotics: A Survey
Humans can learn the use of language through physical interaction with their
environment and semiotic communication with other people. It is very important
to obtain a computational understanding of how humans can form a symbol system
and obtain semiotic skills through their autonomous mental development.
Recently, many studies have been conducted on the construction of robotic
systems and machine-learning methods that can learn the use of language through
embodied multimodal interaction with their environment and other systems.
Understanding human social interactions and developing a robot that can
smoothly communicate with human users in the long term, requires an
understanding of the dynamics of symbol systems and is crucially important. The
embodied cognition and social interaction of participants gradually change a
symbol system in a constructive manner. In this paper, we introduce a field of
research called symbol emergence in robotics (SER). SER is a constructive
approach towards an emergent symbol system. The emergent symbol system is
socially self-organized through both semiotic communications and physical
interactions with autonomous cognitive developmental agents, i.e., humans and
developmental robots. Specifically, we describe some state-of-art research
topics concerning SER, e.g., multimodal categorization, word discovery, and a
double articulation analysis, that enable a robot to obtain words and their
embodied meanings from raw sensory--motor information, including visual
information, haptic information, auditory information, and acoustic speech
signals, in a totally unsupervised manner. Finally, we suggest future
directions of research in SER.Comment: submitted to Advanced Robotic
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