9 research outputs found
Closed-loop Bayesian Semantic Data Fusion for Collaborative Human-Autonomy Target Search
In search applications, autonomous unmanned vehicles must be able to
efficiently reacquire and localize mobile targets that can remain out of view
for long periods of time in large spaces. As such, all available information
sources must be actively leveraged -- including imprecise but readily available
semantic observations provided by humans. To achieve this, this work develops
and validates a novel collaborative human-machine sensing solution for dynamic
target search. Our approach uses continuous partially observable Markov
decision process (CPOMDP) planning to generate vehicle trajectories that
optimally exploit imperfect detection data from onboard sensors, as well as
semantic natural language observations that can be specifically requested from
human sensors. The key innovation is a scalable hierarchical Gaussian mixture
model formulation for efficiently solving CPOMDPs with semantic observations in
continuous dynamic state spaces. The approach is demonstrated and validated
with a real human-robot team engaged in dynamic indoor target search and
capture scenarios on a custom testbed.Comment: Final version accepted and submitted to 2018 FUSION Conference
(Cambridge, UK, July 2018
HARPS: An Online POMDP Framework for Human-Assisted Robotic Planning and Sensing
Autonomous robots can benefit greatly from human-provided semantic
characterizations of uncertain task environments and states. However, the
development of integrated strategies which let robots model, communicate, and
act on such 'soft data' remains challenging. Here, the Human Assisted Robotic
Planning and Sensing (HARPS) framework is presented for active semantic sensing
and planning in human-robot teams to address these gaps by formally combining
the benefits of online sampling-based POMDP policies, multimodal semantic
interaction, and Bayesian data fusion. This approach lets humans
opportunistically impose model structure and extend the range of semantic soft
data in uncertain environments by sketching and labeling arbitrary landmarks
across the environment. Dynamic updating of the environment model while during
search allows robotic agents to actively query humans for novel and relevant
semantic data, thereby improving beliefs of unknown environments and states for
improved online planning. Simulations of a UAV-enabled target search
application in a large-scale partially structured environment show significant
improvements in time and belief state estimates required for interception
versus conventional planning based solely on robotic sensing. Human subject
studies in the same environment (n = 36) demonstrate an average doubling in
dynamic target capture rate compared to the lone robot case, and highlight the
robustness of active probabilistic reasoning and semantic sensing over a range
of user characteristics and interaction modalities
Sharper angle, higher risk? The effect of cutting angle on knee mechanics in invasion sport athletes
Acting on non-communicable diseases in low- and middle-income tropical countries
The classical portrayal of poor health in tropical countries is one of infections and parasites, contrasting with wealthy western countries, where unhealthy diet and behaviours cause non-communicable diseases (NCDs) like heart disease and cancer. Using international mortality data, we show that most NCDs cause more deaths at any age in low- and middle-income tropical countries than in high-income western countries. Causes of NCDs in low- and middle-income countries include poor nutrition and living environment, infections, insufficient regulation of tobacco and alcohol, and under-resourced and inaccessible healthcare. We identify a comprehensive set of actions across health, social, economic and environmental sectors that can confront NCDs in low- and middle-income tropical countries and reduce global health inequalities
Prenatal sex hormone effects on child and adult sex-typed behavior: methods and findings
There is now good evidence that human sex-typed behavior is influenced by sex hormones that are present during prenatal development, confirming studies in other mammalian species. Most of the evidence comes from clinical populations, in which prenatal hormone exposure is atypical for a person's sex, but there is increasing evidence from the normal population for the importance of prenatal hormones. In this paper, we briefly review the evidence, focusing attention on the methods used to study behavioral effects of prenatal hormones. We discuss the promises and pitfalls of various types of studies, including those using clinical populations (concentrating on those most commonly studied, congenital adrenal hyperplasia, androgen insensitivity syndrome, ablatio penis, and cloacal exstrophy), direct measures of hormones in the general population (assayed through umbilical cord blood, amniotic fluid, and maternal serum during pregnancy), and indirect measures of hormones in the general population (inferred from intrauterine position and biomarkers such as otoacoustic emissions, finger length ratios, and dermatoglyphic asymmetries). We conclude with suggestions for interpreting and conducting studies of the behavioral effects of prenatal hormones. © 2004 Elsevier Ltd. All rights reserved