184 research outputs found
Genes encoding hub and bottleneck enzymes of the Arabidopsis metabolic network preferentially retain homeologs through whole genome duplication
<p>Abstract</p> <p>Background</p> <p>Whole genome duplication (WGD) occurs widely in angiosperm evolution. It raises the intriguing question of how interacting networks of genes cope with this dramatic evolutionary event.</p> <p>Results</p> <p>In study of the <it>Arabidopsis </it>metabolic network, we assigned each enzyme (node) with topological centralities (in-degree, out-degree and between-ness) to measure quantitatively their centralities in the network. The <it>Arabidopsis </it>metabolic network is highly modular and separated into 11 interconnected modules, which correspond well to the functional metabolic pathways. The enzymes with higher in-out degree and between-ness (defined as hub and bottleneck enzymes, respectively) tend to be more conserved and preferentially retain homeologs after WGD. Moreover, the simultaneous retention of homeologs encoding enzymes which catalyze consecutive steps in a pathway is highly favored and easily achieved, and enzyme-enzyme interactions contribute to the retention of one-third of WGD enzymes.</p> <p>Conclusions</p> <p>Our analyses indicate that the hub and bottleneck enzymes of metabolic network obtain great benefits from WGD, and this event grants clear evolutionary advantages in adaptation to different environments.</p
Bifurcation of Limit Cycles and Center Conditions for Two Families of Kukles-Like Systems with Nilpotent Singularities
We solve theoretically the center problem and the cyclicity of the Hopf bifurcation for two families of Kukles-like systems with their origins being nilpotent and monodromic isolated singular points
Complete Solution for Vehicle Re-ID in Surround-view Camera System
Vehicle re-identification (Re-ID) is a critical component of the autonomous
driving perception system, and research in this area has accelerated in recent
years. However, there is yet no perfect solution to the vehicle
re-identification issue associated with the car's surround-view camera system.
Our analysis identifies two significant issues in the aforementioned scenario:
i) It is difficult to identify the same vehicle in many picture frames due to
the unique construction of the fisheye camera. ii) The appearance of the same
vehicle when seen via the surround vision system's several cameras is rather
different. To overcome these issues, we suggest an integrative vehicle Re-ID
solution method. On the one hand, we provide a technique for determining the
consistency of the tracking box drift with respect to the target. On the other
hand, we combine a Re-ID network based on the attention mechanism with spatial
limitations to increase performance in situations involving multiple cameras.
Finally, our approach combines state-of-the-art accuracy with real-time
performance. We will soon make the source code and annotated fisheye dataset
available.Comment: 11 pages, 10 figures. arXiv admin note: substantial text overlap with
arXiv:2006.1650
Surround-view Fisheye BEV-Perception for Valet Parking: Dataset, Baseline and Distortion-insensitive Multi-task Framework
Surround-view fisheye perception under valet parking scenes is fundamental
and crucial in autonomous driving. Environmental conditions in parking lots
perform differently from the common public datasets, such as imperfect light
and opacity, which substantially impacts on perception performance. Most
existing networks based on public datasets may generalize suboptimal results on
these valet parking scenes, also affected by the fisheye distortion. In this
article, we introduce a new large-scale fisheye dataset called Fisheye Parking
Dataset(FPD) to promote the research in dealing with diverse real-world
surround-view parking cases. Notably, our compiled FPD exhibits excellent
characteristics for different surround-view perception tasks. In addition, we
also propose our real-time distortion-insensitive multi-task framework Fisheye
Perception Network (FPNet), which improves the surround-view fisheye BEV
perception by enhancing the fisheye distortion operation and multi-task
lightweight designs. Extensive experiments validate the effectiveness of our
approach and the dataset's exceptional generalizability.Comment: 12 pages, 11 figure
ADU-Depth: Attention-based Distillation with Uncertainty Modeling for Depth Estimation
Monocular depth estimation is challenging due to its inherent ambiguity and
ill-posed nature, yet it is quite important to many applications. While recent
works achieve limited accuracy by designing increasingly complicated networks
to extract features with limited spatial geometric cues from a single RGB
image, we intend to introduce spatial cues by training a teacher network that
leverages left-right image pairs as inputs and transferring the learned 3D
geometry-aware knowledge to the monocular student network. Specifically, we
present a novel knowledge distillation framework, named ADU-Depth, with the
goal of leveraging the well-trained teacher network to guide the learning of
the student network, thus boosting the precise depth estimation with the help
of extra spatial scene information. To enable domain adaptation and ensure
effective and smooth knowledge transfer from teacher to student, we apply both
attention-adapted feature distillation and focal-depth-adapted response
distillation in the training stage. In addition, we explicitly model the
uncertainty of depth estimation to guide distillation in both feature space and
result space to better produce 3D-aware knowledge from monocular observations
and thus enhance the learning for hard-to-predict image regions. Our extensive
experiments on the real depth estimation datasets KITTI and DrivingStereo
demonstrate the effectiveness of the proposed method, which ranked 1st on the
challenging KITTI online benchmark.Comment: accepted by CoRL 202
OCR-RTPS: An OCR-based real-time positioning system for the valet parking
Obtaining the position of ego-vehicle is a crucial prerequisite for automatic
control and path planning in the field of autonomous driving. Most existing
positioning systems rely on GPS, RTK, or wireless signals, which are arduous to
provide effective localization under weak signal conditions. This paper
proposes a real-time positioning system based on the detection of the parking
numbers as they are unique positioning marks in the parking lot scene. It does
not only can help with the positioning with open area, but also run
independently under isolation environment. The result tested on both public
datasets and self-collected dataset show that the system outperforms others in
both performances and applies in practice. In addition, the code and dataset
will release later.Comment: 25 pages, 9 figure
Visual characterization of associative quasitrivial nondecreasing operations on finite chains
In this paper we provide visual characterization of associative quasitrivial
nondecreasing operations on finite chains. We also provide a characterization
of bisymmetric quasitrivial nondecreasing binary operations on finite chains.
Finally, we estimate the number of functions belonging to the previous classes.Comment: 25 pages, 18 Figure
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