351 research outputs found
“Ekphrasis”: A Study of Transmedia Narrative in the Works of A.S. Byatt
With the development of transmedia research, many writers begin to pay attention to the comparison and transformation between literature and other artistic media, and practice it in literary creation. Contemporary English novelist A.S. Byatt is one of the practitioners of transmedia literary creation. Through the use of “ekphrasis”, she skillfully and naturally integrates the art work into the literary creation, making the text have a visual effect. This paper takes A.S. Byatt’s three short stories Christ in the House of Martha and Mary, Art Work and Rose-Colored Teacup as examples to explore the ekphrarstic re-creation of paintings, sculptures and pottery in her works, and then analyzes the deep connotation brought by the ekphrasis between different artistic media to literary texts
Permanence and Stability of an Age-Structured Prey-Predator System with Delays
An age-structured prey-predator model with delays is proposed and analyzed. Mathematical analyses of the model equations with regard to boundedness of solutions, permanence, and stability are analyzed. By using the persistence theory for infinite-dimensional systems, the sufficient conditions for the permanence of the system are obtained. By constructing suitable Lyapunov functions and using an iterative technique, sufficient conditions are also obtained for the global asymptotic stability of the positive equilibrium of the model
An Extrinsic Calibration Method of a 3D-LiDAR and a Pose Sensor for Autonomous Driving
Accurate and reliable sensor calibration is critical for fusing LiDAR and
inertial measurements in autonomous driving. This paper proposes a novel
three-stage extrinsic calibration method of a 3D-LiDAR and a pose sensor for
autonomous driving. The first stage can quickly calibrate the extrinsic
parameters between the sensors through point cloud surface features so that the
extrinsic can be narrowed from a large initial error to a small error range in
little time. The second stage can further calibrate the extrinsic parameters
based on LiDAR-mapping space occupancy while removing motion distortion. In the
final stage, the z-axis errors caused by the plane motion of the autonomous
vehicle are corrected, and an accurate extrinsic parameter is finally obtained.
Specifically, This method utilizes the natural characteristics of road scenes,
making it independent and easy to apply in large-scale conditions. Experimental
results on real-world data sets demonstrate the reliability and accuracy of our
method. The codes are open-sourced on the Github website. To the best of our
knowledge, this is the first open-source code specifically designed for
autonomous driving to calibrate LiDAR and pose-sensor extrinsic parameters. The
code link is https://github.com/OpenCalib/LiDAR2INS.Comment: 7 pages, 12 figure
Specify Robust Causal Representation from Mixed Observations
Learning representations purely from observations concerns the problem of
learning a low-dimensional, compact representation which is beneficial to
prediction models. Under the hypothesis that the intrinsic latent factors
follow some casual generative models, we argue that by learning a causal
representation, which is the minimal sufficient causes of the whole system, we
can improve the robustness and generalization performance of machine learning
models. In this paper, we develop a learning method to learn such
representation from observational data by regularizing the learning procedure
with mutual information measures, according to the hypothetical factored causal
graph. We theoretically and empirically show that the models trained with the
learned causal representations are more robust under adversarial attacks and
distribution shifts compared with baselines. The supplementary materials are
available at https://github.com/ymy .Comment: arXiv admin note: substantial text overlap with arXiv:2202.0838
Knee-point-conscious battery aging trajectory prediction of lithium-ion based on physics-guided machine learning
Early prediction of aging trajectories of lithium-ion (Li-ion) batteries is critical for cycle life testing, quality control, and battery health management. Although data-driven machine learning (ML) approaches are well suited for this task, unfortunately, relying solely on data is exceedingly time-consuming and resource-intensive, even in accelerated aging with complex aging mechanisms. This challenge is rooted in the highly complex and time-varying degradation mechanisms of Li-ion battery cells. We propose a novel method based on physics-guided machine learning (PGML) to overcome this issue. First, electrode-level physical information is incorporated into the model training process to predict the aging trajectory’s knee point (KP). The relationship between the identified KP and the accelerated aging behavior is then explored, and an aging trajectory prediction algorithm is developed. The prior knowledge of aging mechanisms enables a transfer of valuable physical insights to yield accurate KP predictions with small data and weak correlation feature relationship. Based on a Li[NiCoMn]O\ua02\ua0cell dataset, we demonstrate that only 14 cells are needed to train a PGML model for achieving a lifetime prediction error of 2.02% using the data of the first 50 cycles. In contrast, at least 100 cells are needed to reach this level of accuracy without the physical insights
Analyzing Infrastructure LiDAR Placement with Realistic LiDAR Simulation Library
Recently, Vehicle-to-Everything(V2X) cooperative perception has attracted
increasing attention. Infrastructure sensors play a critical role in this
research field; however, how to find the optimal placement of infrastructure
sensors is rarely studied. In this paper, we investigate the problem of
infrastructure sensor placement and propose a pipeline that can efficiently and
effectively find optimal installation positions for infrastructure sensors in a
realistic simulated environment. To better simulate and evaluate LiDAR
placement, we establish a Realistic LiDAR Simulation library that can simulate
the unique characteristics of different popular LiDARs and produce
high-fidelity LiDAR point clouds in the CARLA simulator. Through simulating
point cloud data in different LiDAR placements, we can evaluate the perception
accuracy of these placements using multiple detection models. Then, we analyze
the correlation between the point cloud distribution and perception accuracy by
calculating the density and uniformity of regions of interest. Experiments show
that when using the same number and type of LiDAR, the placement scheme
optimized by our proposed method improves the average precision by 15%,
compared with the conventional placement scheme in the standard lane scene. We
also analyze the correlation between perception performance in the region of
interest and LiDAR point cloud distribution and validate that density and
uniformity can be indicators of performance. Both the RLS Library and related
code will be released at
https://github.com/PJLab-ADG/LiDARSimLib-and-Placement-Evaluation.Comment: 7 pages, 6 figures, accepted to the IEEE International Conference on
Robotics and Automation (ICRA'23
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