4,713 research outputs found
REAL: Resilience and Adaptation using Large Language Models on Autonomous Aerial Robots
Large Language Models (LLMs) pre-trained on internet-scale datasets have
shown impressive capabilities in code understanding, synthesis, and general
purpose question-and-answering. Key to their performance is the substantial
prior knowledge acquired during training and their ability to reason over
extended sequences of symbols, often presented in natural language. In this
work, we aim to harness the extensive long-term reasoning, natural language
comprehension, and the available prior knowledge of LLMs for increased
resilience and adaptation in autonomous mobile robots. We introduce REAL, an
approach for REsilience and Adaptation using LLMs. REAL provides a strategy to
employ LLMs as a part of the mission planning and control framework of an
autonomous robot. The LLM employed by REAL provides (i) a source of prior
knowledge to increase resilience for challenging scenarios that the system had
not been explicitly designed for; (ii) a way to interpret natural-language and
other log/diagnostic information available in the autonomy stack, for mission
planning; (iii) a way to adapt the control inputs using minimal user-provided
prior knowledge about the dynamics/kinematics of the robot. We integrate REAL
in the autonomy stack of a real multirotor, querying onboard an offboard LLM at
0.1-1.0 Hz as part the robot's mission planning and control feedback loops. We
demonstrate in real-world experiments the ability of the LLM to reduce the
position tracking errors of a multirotor under the presence of (i) errors in
the parameters of the controller and (ii) unmodeled dynamics. We also show
(iii) decision making to avoid potentially dangerous scenarios (e.g., robot
oscillates) that had not been explicitly accounted for in the initial prompt
design.Comment: 13 pages, 5 figures, conference worksho
Biomass yield and heterosis of crosses within and between European winter cultivars of turnip rape (Brassica rapa L.)
Because of its high growth rate at low temperatures in early spring, there is renewed interest in Brassica rapa as a winter crop for biomass production in Europe. The available cultivars are not developed for this purpose however. An approach for breeding bioenergy cultivars of B. rapa could be to establish populations from two or more different cultivars with high combining ability. The objective of this study was to evaluate the heterosis for biomass yield in the European winter B. rapa genepool. The genetic variation and heterosis of the biomass parameters: dry matter content, fresh and dry biomass yields were investigated in three cultivars representing different eras of breeding by comparing full-sibs-within and full-sibs-between the cultivars. Field trials were performed at two locations in Germany in 2005–2006. Mean mid-parent heterosis was low with 2.5% in fresh and 3.0% in dry biomass yield in full-sibs-between cultivars. Mean values of individual crosses revealed a higher variation in mid-parent heterosis ranging from 14.6% to −7.5% in fresh biomass yield and from 19.7% to −12.7% in dry biomass yield. The low heterosis observed in hybrids between European winter cultivars can be explained by the low genetic variation between these cultivars as shown earlier with molecular markers. In conclusion, a B. rapa breeding program for biomass production in Europe should not only use European genetic resources, but should also utilize the much wider worldwide variation in this species
Comprehensive Calculations on the OZI-forbidden Nonleptonic Decays of Orthoquarkonia
In this work, we calculate the decay rates of the OZI-forbidden processes
at the order of the leading-twist
distribution amplitude. The process of
violates isospin conservation and the amplitude is explicitly proportional to
the isospin violation factor , our numerical results on their decay
rates are consistent with the data. The process
violates the hadronic helicity conservation and should be suppressed, as
indicated in literature, its decay rate can only be proportional to at
the order of leading twist. Our theoretical evaluation confirms this statement
that the theoretical evaluation on is
almost one order smaller than the data unless the model parameters take certain
extreme values. It may imply that the sizable branching ratio of
should be explained by either higher twist
contributions or other mechanisms.Comment: 25 pages, 1 figure and 4 tables. Numerical results slightly change
Correlation dynamics between electrons and ions in the fragmentation of D molecules by short laser pulses
We studied the recollision dynamics between the electrons and D ions
following the tunneling ionization of D molecules in an intense short pulse
laser field. The returning electron collisionally excites the D ion to
excited electronic states from there D can dissociate or be further
ionized by the laser field, resulting in D + D or D + D,
respectively. We modeled the fragmentation dynamics and calculated the
resulting kinetic energy spectrum of D to compare with recent experiments.
Since the recollision time is locked to the tunneling ionization time which
occurs only within fraction of an optical cycle, the peaks in the D kinetic
energy spectra provides a measure of the time when the recollision occurs. This
collision dynamics forms the basis of the molecular clock where the clock can
be read with attosecond precision, as first proposed by Corkum and coworkers.
By analyzing each of the elementary processes leading to the fragmentation
quantitatively, we identified how the molecular clock is to be read from the
measured kinetic energy spectra of D and what laser parameters be used in
order to measure the clock more accurately.Comment: 13 pages with 14 figure
Heat conduction in one dimensional nonintegrable systems
Two classes of 1D nonintegrable systems represented by the Fermi-Pasta-Ulam
(FPU) model and the discrete model are studied to seek a generic
mechanism of energy transport in microscopic level sustaining macroscopic
behaviors. The results enable us to understand why the class represented by the
model has a normal thermal conductivity and the class represented by
the FPU model does not even though the temperature gradient can be established.Comment: 4 Revtex Pages, 4 Eps figures included, to appear in Phys. Rev. E,
March 200
Initial-state dependence in time-dependent density functional theory
Time-dependent density functionals in principle depend on the initial state
of the system, but this is ignored in functional approximations presently in
use. For one electron it is shown there is no initial-state dependence: for any
density, only one initial state produces a well-behaved potential. For two
non-interacting electrons with the same spin in one-dimension, an initial
potential that makes an alternative initial wavefunction evolve with the same
density and current as a ground state is calculated. This potential is
well-behaved and can be made arbitrarily different from the original potential
A Novel Five-Phase Fractional Slot Concentrated Winding with Low Space Harmonic Contents
In this article, a novel five-phase fractional-slot concentrated winding (FSCW) with 20-slot/22-pole is presented. It benefits not only the advantages of conventional FSCW but also weak space harmonics of magnetomotive force (MMF). The winding allows eliminating the first sub-order harmonic. The new layout of the winding topology is obtained by a combination of stator shift technique of the winding in the slots with a special coupling of the windings (star-pentagon), using winding function theory. The high performances of the new winding layout are validated using the finite element method (FEM). Compared to the conventional winding, the winding factor and the total harmonic distortion (THD) of MMF are improved by 1.3% and 2.2%, respectively. With the same injection of current density, the average output torque is increased by 1% and the torque ripple is decreased by 60%. The eddy current losses in the permanent magnets (PMs) at rated speed (600 r/min) and 2100 r/min speed are improved by 67% and 56%, respectively
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