132 research outputs found
A Generalized Recurrent Neural Architecture for Text Classification with Multi-Task Learning
Multi-task learning leverages potential correlations among related tasks to
extract common features and yield performance gains. However, most previous
works only consider simple or weak interactions, thereby failing to model
complex correlations among three or more tasks. In this paper, we propose a
multi-task learning architecture with four types of recurrent neural layers to
fuse information across multiple related tasks. The architecture is
structurally flexible and considers various interactions among tasks, which can
be regarded as a generalized case of many previous works. Extensive experiments
on five benchmark datasets for text classification show that our model can
significantly improve performances of related tasks with additional information
from others
A Novel Method of Robust Trajectory Linearization Control Based on Disturbance Rejection
A novel method of robust trajectory linearization control for a class of nonlinear systems with uncertainties based on disturbance rejection is proposed. Firstly, on the basis of trajectory linearization control (TLC) method, a feedback linearization based control law is designed to transform the original tracking error dynamics to the canonical integral-chain form. To address the issue of reducing the influence made by uncertainties, with tracking error as input, linear extended state observer (LESO) is constructed to estimate the tracking error vector, as well as the uncertainties in an integrated manner. Meanwhile, the boundedness of the estimated error is investigated by theoretical analysis. In addition, decoupled controller (which has the characteristic of well-tuning and simple form) based on LESO is synthesized to realize the output tracking for closed-loop system. The closed-loop stability of the system under the proposed LESO-based control structure is established. Also, simulation results are presented to illustrate the effectiveness of the control strategy
Antidisturbance Vibration Suppression of the Aerial Refueling Hose during the Coupling Process
In autonomous aerial refueling (AAR), the vibration of the flexible refueling hose caused by the receiver aircraft’s excessive closure speed should be suppressed once it appears. This paper proposed an active control strategy based on the permanent magnet synchronous motor (PMSM) angular control for the timely and accurate vibration suppression of the flexible refueling hose. A nonsingular fast terminal sliding-mode (NFTSM) control scheme with adaptive extended state observer (AESO) is proposed for PMSM take-up system under multiple disturbances. The states and the “total disturbance” of the PMSM system are firstly reconstituted using the AESO under the uncertainties and measurement noise. Then, a faster sliding variable with tracking error exponential term is proposed together with a special designed reaching law to enhance the global convergence speed and precision of the controller. The proposed control scheme provides a more comprehensive solution to rapidly suppress the flexible refueling hose vibration in AAR. Compared to other methods, the scheme can suppress the flexible hose vibration more fleetly and accurately even when the system is exposed to multiple disturbances and measurement noise. Simulation results show that the proposed scheme is competitive in accuracy, global rapidity, and robustness
Irradiation Behaviour of High Entropy Alloys
Four high entropy alloys (HEA), CoCrCuFeNi, Co1.5CrFeNi1.5Ti0.5Mo0.1, both adopting an FCC structure, and TaNbHfZrTi, and AlCoCrFeNiSi, adopting a BCC structure, have been irradiated with He and 3 MeV Ni ions, as part of the process of understanding their application within fission based nuclear reactors. When irradiated nano-indentation analysis shows that the FCC and BCC respond differently. The FCC phases show a decrease in hardness with increasing ion fluence, for example at depth of 100nm CoCrCuFeNi shows a decrease from ~7.5 GPa to ~4.5 GPa. However, the BCC phases show an initial increase in hardness with ion fluence, for example at a depth of 100nm TaNbHfZrTi, shows an intial increase from ~9.5 GPa to ~ 10.2 GPa, with a subsequent drop to ~8.75 GPa. Transmission electron microscopy based analysis shows that ion beam induced damage is visible in the samples, with 3 MeV Ni inducing differing levels of visible damage. Analysis of He irradiated samples suggests that there might be beginnings of bubble formation, but the evidence is not clear cut
VFHQ: A High-Quality Dataset and Benchmark for Video Face Super-Resolution
Most of the existing video face super-resolution (VFSR) methods are trained
and evaluated on VoxCeleb1, which is designed specifically for speaker
identification and the frames in this dataset are of low quality. As a
consequence, the VFSR models trained on this dataset can not output
visual-pleasing results. In this paper, we develop an automatic and scalable
pipeline to collect a high-quality video face dataset (VFHQ), which contains
over high-fidelity clips of diverse interview scenarios. To verify the
necessity of VFHQ, we further conduct experiments and demonstrate that VFSR
models trained on our VFHQ dataset can generate results with sharper edges and
finer textures than those trained on VoxCeleb1. In addition, we show that the
temporal information plays a pivotal role in eliminating video consistency
issues as well as further improving visual performance. Based on VFHQ, by
analyzing the benchmarking study of several state-of-the-art algorithms under
bicubic and blind settings. See our project page:
https://liangbinxie.github.io/projects/vfhqComment: Project webpage available at
https://liangbinxie.github.io/projects/vfh
- …