7 research outputs found
Indoor Exploration and Simultaneous Trolley Collection Through Task-Oriented Environment Partitioning
In this paper, we present a simultaneous exploration and object search
framework for the application of autonomous trolley collection. For environment
representation, a task-oriented environment partitioning algorithm is presented
to extract diverse information for each sub-task. First, LiDAR data is
classified as potential objects, walls, and obstacles after outlier removal.
Segmented point clouds are then transformed into a hybrid map with the
following functional components: object proposals to avoid missing trolleys
during exploration; room layouts for semantic space segmentation; and polygonal
obstacles containing geometry information for efficient motion planning. For
exploration and simultaneous trolley collection, we propose an efficient
exploration-based object search method. First, a traveling salesman problem
with precedence constraints (TSP-PC) is formulated by grouping frontiers and
object proposals. The next target is selected by prioritizing object search
while avoiding excessive robot backtracking. Then, feasible trajectories with
adequate obstacle clearance are generated by topological graph search. We
validate the proposed framework through simulations and demonstrate the system
with real-world autonomous trolley collection tasks
Collaborative Trolley Transportation System with Autonomous Nonholonomic Robots
Cooperative object transportation using multiple robots has been intensively
studied in the control and robotics literature, but most approaches are either
only applicable to omnidirectional robots or lack a complete navigation and
decision-making framework that operates in real time. This paper presents an
autonomous nonholonomic multi-robot system and an end-to-end hierarchical
autonomy framework for collaborative luggage trolley transportation. This
framework finds kinematic-feasible paths, computes online motion plans, and
provides feedback that enables the multi-robot system to handle long lines of
luggage trolleys and navigate obstacles and pedestrians while dealing with
multiple inherently complex and coupled constraints. We demonstrate the
designed collaborative trolley transportation system through practical
transportation tasks, and the experiment results reveal their effectiveness and
reliability in complex and dynamic environments
IllustrisTNG in the HSC-SSP: image data release and the major role of mini mergers as drivers of asymmetry and star formation
At fixed galaxy stellar mass, there is a clear observational connection
between structural asymmetry and offset from the star forming main sequence,
SFMS. Herein, we use the TNG50 simulation to investigate the relative
roles of major mergers (stellar mass ratios ), minor (), and mini mergers () in driving this
connection amongst star forming galaxies (SFGs). We use dust radiative transfer
post-processing with SKIRT to make a large, public collection of synthetic
Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) images of simulated TNG
galaxies over with (k images). Using their instantaneous SFRs,
known merger histories/forecasts, and HSC-SSP asymmetries, we show (1) that
TNG50 SFGs qualitatively reproduce the observed trend between SFMS and
asymmetry and (2) a strikingly similar trend emerges between SFMS and
the time-to-coalescence for mini mergers. Controlling for redshift, stellar
mass, environment, and gas fraction, we show that individual mini merger events
yield small enhancements in SFRs and asymmetries that are sustained on long
timescales (at least Gyr after coalescence, on average) -- in contrast
to major/minor merger remnants which peak at much greater amplitudes but are
consistent with controls only Gyr after coalescence. Integrating the
boosts in SFRs and asymmetries driven by mergers since in
TNG50 SFGs, we show that mini mergers are responsible for (i) per cent of
all merger-driven star formation and (ii) per cent of merger-driven
asymmetric structure. Due to their relative frequency and prolonged boost
timescales, mini mergers dominate over their minor and major counterparts in
driving star formation and asymmetry in SFGs.Comment: 32 pages; 18 figures; submitted to MNRAS; Image data available via
the TNG website: www.tng-project.org/bottrell2
Neural network model based on global and local features for multi-view mammogram classification
Mammography is an important screening criterion for breast cancer, one of the major diseases causing numerous deaths among female patients. Meanwhile, manual diagnosis of mammography is a time-consuming and labor-consuming job. Mammogram classification based on deep learning plays a vital role in computer-aided diagnosis (CAD) systems to mitigate the pressure on physicians. This paper proposes a learning-based multi-view mammogram classification model that captures long-distance dependence and extracts features of multiple receptive fields. Our model considers global and local features of mammography images using Transformer for global features and the proposed multiplex convolutions module for local features. We evaluate our proposed method on a dataset of mammography images obtained from a hospital in China. The proposed method achieves 90.57% accuracy and 94.86% AUC in benign or malignant classification tasks and outperforms other advanced methods for mammogram classification. It is worth noting that the proposed method only requires image-level labels and acts on the whole raw mammogram, which has clinical significance
Resistance Risk and Resistance-Related Point Mutations in Target Protein Cyt b of the Quinone Inside Inhibitor Amisulbrom in Phytophthora litchii
Amisulbrom is a novel quinone inside inhibitor, which
exhibits
excellent inhibitory activity against phytopathogenic oomycetes. However,
the resistance risk and mechanism of amisulbrom in Phytophthora litchii are rarely reported. In this
study, the sensitivity of 147 P. litchii isolates to amisulbrom was determined, with an average EC50 of 0.24 ± 0.11 μg/mL. The fitness of resistant mutants,
obtained by fungicide adaption, was significantly lower than that
of the parental isolates in vitro. Cross-resistance
was detected between amisulbrom and cyazofamid. Amisulbrom could not
inhibit the cytochrome bc1 complex activity with H15Y and G30E + F220L
point mutations in cytochrome b (Cyt b) in vitro.
Molecular docking indicated that the H15Y or G30E point mutation can
decrease the binding energy between amisulbrom and P. litchii Cyt b. In conclusion, P.
litchii might have a medium resistance risk to amisulbrom,
and a novel point mutation H15Y or G30E in Cyt b could cause high
amisulbrom resistance in P. litchii