1,005 research outputs found
FedBEVT: Federated Learning Bird's Eye View Perception Transformer in Road Traffic Systems
Bird's eye view (BEV) perception is becoming increasingly important in the
field of autonomous driving. It uses multi-view camera data to learn a
transformer model that directly projects the perception of the road environment
onto the BEV perspective. However, training a transformer model often requires
a large amount of data, and as camera data for road traffic are often private,
they are typically not shared. Federated learning offers a solution that
enables clients to collaborate and train models without exchanging data but
model parameters. In this paper, we introduce FedBEVT, a federated transformer
learning approach for BEV perception. In order to address two common data
heterogeneity issues in FedBEVT: (i) diverse sensor poses, and (ii) varying
sensor numbers in perception systems, we propose two approaches -- Federated
Learning with Camera-Attentive Personalization (FedCaP) and Adaptive
Multi-Camera Masking (AMCM), respectively. To evaluate our method in real-world
settings, we create a dataset consisting of four typical federated use cases.
Our findings suggest that FedBEVT outperforms the baseline approaches in all
four use cases, demonstrating the potential of our approach for improving BEV
perception in autonomous driving.Comment: Accepted by IEEE T-IV. Code: https://github.com/rruisong/FedBEV
Transformation Decoupling Strategy based on Screw Theory for Deterministic Point Cloud Registration with Gravity Prior
Point cloud registration is challenging in the presence of heavy outlier
correspondences. This paper focuses on addressing the robust
correspondence-based registration problem with gravity prior that often arises
in practice. The gravity directions are typically obtained by inertial
measurement units (IMUs) and can reduce the degree of freedom (DOF) of rotation
from 3 to 1. We propose a novel transformation decoupling strategy by
leveraging screw theory. This strategy decomposes the original 4-DOF problem
into three sub-problems with 1-DOF, 2-DOF, and 1-DOF, respectively, thereby
enhancing the computation efficiency. Specifically, the first 1-DOF represents
the translation along the rotation axis and we propose an interval
stabbing-based method to solve it. The second 2-DOF represents the pole which
is an auxiliary variable in screw theory and we utilize a branch-and-bound
method to solve it. The last 1-DOF represents the rotation angle and we propose
a global voting method for its estimation. The proposed method sequentially
solves three consensus maximization sub-problems, leading to efficient and
deterministic registration. In particular, it can even handle the
correspondence-free registration problem due to its significant robustness.
Extensive experiments on both synthetic and real-world datasets demonstrate
that our method is more efficient and robust than state-of-the-art methods,
even when dealing with outlier rates exceeding 99%
Detector dead-time effects and paralyzability in high-speed quantum key distribution
Recent advances in quantum key distribution (QKD) have given rise to systems
that operate at transmission periods significantly shorter than the dead times
of their component single-photon detectors. As systems continue to increase in
transmission rate, security concerns associated with detector dead times can
limit the production rate of sifted bits. We present a model of high-speed QKD
in this limit that identifies an optimum transmission rate for a system with
given link loss and detector response characteristics
Phi-Meson Production at RHIC, Strong Color Fields and Intrinsic Transverse Momenta
We investigate the effects of strong color fields and of the associated
enhanced intrinsic transverse momenta on the phi-meson production in
ultrarelativistic heavy ion collisions at RHIC. The observed consequences
include a change of the spectral slopes, varying particle ratios, and also
modified mean transverse momenta. In particular, the composition of the
production processes of phi mesons, that is, direct production vs.
coalescence-like production, depends strongly on the strength of the color
fields and intrinsic transverse momenta and thus represents a sensitive probe
for their measurement.Comment: 4 pages, 3 figure
Time-Dependent Hartree-Fock simulation of the expansion of abraded nuclei
A recent interpretation of the caloric curve based on the expansion of the
abraded spectator nucleus is re-analysed in the framework of the Time-Dependent
Hartree-Fock (TDHF) evolution. It is shown that the TDHF dynamics is more
complex than a single monopolar collective motion at moderate energy. The
inclusion of other important collective degrees of freedom may lead to the
dynamical creation of hollow structure. Then, low density regions could be
locally reached after a long time by the creation of these exotic density
profiles. In particular the systematic of the minimum density reached during
the expansion (the so-called turning points) appears to be different.Comment: 30 Latex pages including 9 figure
Data Acquisition and Analysis of the 76Ge Double Beta Experiment in Gran Sasso 1990-2003
Data acquisition in a long running underground experiment has its specific
experimental challenges, concerning data acquisition, stability of the
experiment and background reduction. These problems are addressed here for the
HEIDELBERG-MOSCOW experiment, which collected data in the period August 1990 -
May 2003. The measurement and the analysis of the data is presented. The duty
cycle of the experiment was ~80%, the collected statistics is 71.7 kgy. The
background achieved in the energy region of the Q value for double beta decay
is 0.11 events/kg y keV. The two-neutrino accompanied half-life is determined
on the basis of more than 100 000 events. The confidence level for the
neutrinoless signal has been improved to a 4 sigma level.Comment: Full version (50 pages, 36 figures, 9 tables), zipped ps file (size
~21MB or pdf format (size ~26MB), can be found in
http://www.mpi-hd.mpg.de/non_acc/super.html (corrected typos) In press in NIM
A, 200
Over-pressurized bioreactors : application to microbial cell cultures
In industrial biotechnology, microbial cultures are exposed to different local pressures inside bioreactors. Depending on the microbial species and strains, the increased pressure may have detrimental or beneficial effects on cellular growth and product formation. In this review, the effects of increased air pressure on various microbial cultures growing in bioreactors under moderate total pressure conditions (maximum, 15 bar) will be discussed. Recent data illustrating the diversity of increased air pressure effects at different levels in microbial cells cultivation will be presented, with particular attention to the effects of oxygen and carbon dioxide partial pressures on cellular growth and product formation, and the
concomitant effect of oxygen pressure on antioxidant cellular defense mechanisms.The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the Project "BioInd-Biotechnology and Bioengineering for improved Industrial and Agro-Food processes, REF. NORTE-07-0124-FEDER-000028," cofunded by the Programa Operacional Regional do Norte (ON.2-O Novo Norte), QREN, FEDER. A special aknowledgement is given to FCT for the support to the improvement of infrastructures awarded by the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462)
Over-pressurized bioreactors : application to microbial cell cultures
In industrial biotechnology, microbial cultures are exposed to different local pressures inside bioreactors. Depending on the microbial species and strains, the increased pressure may have detrimental or beneficial effects on cellular growth and product formation. In this review, the effects of increased air pressure on various microbial cultures growing in bioreactors under moderate total pressure conditions (maximum, 15 bar) will be discussed. Recent data illustrating the diversity of increased air pressure effects at different levels in microbial cells cultivation will be presented, with particular attention to the effects of oxygen and carbon dioxide partial pressures on cellular growth and product formation, and the
concomitant effect of oxygen pressure on antioxidant cellular defense mechanisms.The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the Project "BioInd-Biotechnology and Bioengineering for improved Industrial and Agro-Food processes, REF. NORTE-07-0124-FEDER-000028," cofunded by the Programa Operacional Regional do Norte (ON.2-O Novo Norte), QREN, FEDER. A special aknowledgement is given to FCT for the support to the improvement of infrastructures awarded by the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462)
Scans for signatures of selection in Russian cattle breed genomes reveal new candidate genes for environmental adaptation and acclimation
Domestication and selective breeding has resulted in over 1000 extant cattle breeds. Many of these breeds do not excel in important traits but are adapted to local environments. These adaptations are a valuable source of genetic material for efforts to improve commercial breeds. As a step toward this goal we identified candidate regions to be under selection in genomes of nine Russian native cattle breeds adapted to survive in harsh climates. After comparing our data to other breeds of European and Asian origins we found known and novel candidate genes that could potentially be related to domestication, economically important traits and environmental adaptations in cattle. The Russian cattle breed genomes contained regions under putative selection with genes that may be related to adaptations to harsh environments (e.g., AQP5, RAD50, and RETREG1). We found genomic signatures of selective sweeps near key genes related to economically important traits, such as the milk production (e.g., DGAT1, ABCG2), growth (e.g., XKR4), and reproduction (e.g., CSF2). Our data point to candidate genes which should be included in future studies attempting to identify genes to improve the extant breeds and facilitate generation of commercial breeds that fit better into the environments of Russia and other countries with similar climates
Temperatures of Exploding Nuclei
Breakup temperatures in central collisions of 197Au + 197Au at bombarding
energies E/A = 50 to 200 MeV were determined with two methods. Isotope
temperatures, deduced from double ratios of hydrogen, helium, and lithium
isotopic yields, increase monotonically with bombarding energy from 5 MeV to 12
MeV, in qualitative agreement with a scenario of chemical freeze-out after
adiabatic expansion. Excited-state temperatures, derived from yield ratios of
states in 4He, 5Li, 6Li, and 8Be, are about 5 MeV, independent of the
projectile energy, and seem to reflect the internal temperature of fragments at
their final separation from the system.
PACS numbers: 25.70.Mn, 25.70.Pq, 25.75.-qComment: 10 pages, RevTeX with 4 included figures; Also available from
http://www-kp3.gsi.de/www/kp3/aladin_publications.htm
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