1,046 research outputs found
Knowledge Transfer Between Robots with Similar Dynamics for High-Accuracy Impromptu Trajectory Tracking
In this paper, we propose an online learning approach that enables the
inverse dynamics model learned for a source robot to be transferred to a target
robot (e.g., from one quadrotor to another quadrotor with different mass or
aerodynamic properties). The goal is to leverage knowledge from the source
robot such that the target robot achieves high-accuracy trajectory tracking on
arbitrary trajectories from the first attempt with minimal data recollection
and training. Most existing approaches for multi-robot knowledge transfer are
based on post-analysis of datasets collected from both robots. In this work, we
study the feasibility of impromptu transfer of models across robots by learning
an error prediction module online. In particular, we analytically derive the
form of the mapping to be learned by the online module for exact tracking,
propose an approach for characterizing similarity between robots, and use these
results to analyze the stability of the overall system. The proposed approach
is illustrated in simulation and verified experimentally on two different
quadrotors performing impromptu trajectory tracking tasks, where the quadrotors
are required to accurately track arbitrary hand-drawn trajectories from the
first attempt.Comment: European Control Conference (ECC) 201
Weight status in young adulthood and survival after cardiovascular diseases and cancer
Peer reviewe
Hybrid method for determining the parameters of condenser microphones from measured membrane velocities and numerical calculations
Body mass index, asthma and allergic rhinoconjunctivitis in Swedish conscripts—a national cohort study over three decades
SummaryObesity and overweight have been associated with an increased risk of asthma in children as well as adults. The association between atopy and body mass index (BMI) is less clear. It has also been suggested that the link between a high BMI and asthma could be a recent phenomenon. The objective of this study was to assess whether the association with BMI differed between allergic rhinoconjunctivitis and asthma and if these associations have changed over time.The Swedish Military Service Conscription Register was linked to the Register of the Total Population and the Population and Housing Censuses. Asthma (with and without allergic rhinoconjunctivitis) and allergic rhinoconjunctivitis at conscription were analysed in relation to BMI for 1,247,038 male conscripts in successive cohorts born between 1952 and 1977. Obesity was associated with asthma without allergic rhinoconjunctivitis, adjusted OR 1.53 (95% CI 1.43–1.63), and with asthma with allergic rhinoconjunctivitis, adjusted OR 1.34 (95% CI 1.20–1.50), but not with allergic rhinoconjunctivitis, OR 1.00 (95% CI 0.97–1.03) after multivariate analyses with adjustments for confounders. The odds ratios were similar in three successive cohorts (conscripts born in 1952–1961, 1962–1971 and 1972–1977). Underweight was associated with a slightly increased risk for all three conditions. The increased risk of asthma in young Swedish men with obesity has remained unchanged over a period of three decades
Rare finds of the coiled cephalopod <em>Discoceras</em> from the Upper Ordovician of Bornholm, Denmark
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