242 research outputs found
An Integrated Framework Integrating Monte Carlo Tree Search and Supervised Learning for Train Timetabling Problem
The single-track railway train timetabling problem (TTP) is an important and
complex problem. This article proposes an integrated Monte Carlo Tree Search
(MCTS) computing framework that combines heuristic methods, unsupervised
learning methods, and supervised learning methods for solving TTP in discrete
action spaces. This article first describes the mathematical model and
simulation system dynamics of TTP, analyzes the characteristics of the solution
from the perspective of MCTS, and proposes some heuristic methods to improve
MCTS. This article considers these methods as planners in the proposed
framework. Secondly, this article utilizes deep convolutional neural networks
to approximate the value of nodes and further applies them to the MCTS search
process, referred to as learners. The experiment shows that the proposed
heuristic MCTS method is beneficial for solving TTP; The algorithm framework
that integrates planners and learners can improve the data efficiency of
solving TTP; The proposed method provides a new paradigm for solving TTP
Rethinking PRL: A Multiscale Progressively Residual Learning Network for Inverse Halftoning
Image inverse halftoning is a classic image restoration task, aiming to
recover continuous-tone images from halftone images with only bilevel pixels.
Because the halftone images lose much of the original image content, inverse
halftoning is a classic ill-problem. Although existing inverse halftoning
algorithms achieve good performance, their results lose image details and
features. Therefore, it is still a challenge to recover high-quality
continuous-tone images. In this paper, we propose an end-to-end multiscale
progressively residual learning network (MSPRL), which has a UNet architecture
and takes multiscale input images. To make full use of different input image
information, we design a shallow feature extraction module to capture similar
features between images of different scales. We systematically study the
performance of different methods and compare them with our proposed method. In
addition, we employ different training strategies to optimize the model, which
is important for optimizing the training process and improving performance.
Extensive experiments demonstrate that our MSPRL model obtains considerable
performance gains in detail restoration
End of the World Brane meets
End of the world branes in AdS have been recently used to study problems
deeply connected to quantum gravity, such as black hole evaporation and
holographic cosmology. With non-critical tension and Neumann boundary
condition, the end of the world brane often represents part of the degrees of
freedom in AdS gravity and geometrically it is only part of the entire
boundary. On the other hand, holographic deformation can also give a
boundary as a cutoff surface for AdS gravity. In this paper we consider AdS
gravity with both the end of the world boundary and the cutoff boundary. Using
partial reduction we obtain a brane world gravity glued to a
deformed bath. We compute both entanglement entropy and Page curve, and find
agreement between the holographic results and island formula results.Comment: 1+26 pages, 11 figure
High-Power and Ultralong-Life Aqueous Zinc-Ion Hybrid Capacitors Based on Pseudocapacitive Charge Storage
© 2019, © 2019, The Author(s). Rechargeable aqueous zinc-ion hybrid capacitors and zinc-ion batteries are promising safe energy storage systems. In this study, amorphous RuO2·H2O for the first time was employed to achieve fast and ultralong-life Zn2+ storage based on a pseudocapacitive storage mechanism. In the RuO2·H2O||Zn zinc-ion hybrid capacitors with Zn(CF3SO3)2 aqueous electrolyte, the RuO2·H2O cathode can reversibly store Zn2+ in a voltage window of 0.4–1.6 V (vs. Zn/Zn2+), delivering a high discharge capacity of 122 mAh g−1. In particular, the zinc-ion hybrid capacitors can be rapidly charged/discharged within 36 s with a very high power density of 16.74 kW kg−1 and a high energy density of 82 Wh kg−1. Besides, the zinc-ion hybrid capacitors demonstrate an ultralong cycle life (over 10,000 charge/discharge cycles). The kinetic analysis elucidates that the ultrafast Zn2+ storage in the RuO2·H2O cathode originates from redox pseudocapacitive reactions. This work could greatly facilitate the development of high-power and safe electrochemical energy storage.[Figure not available: see fulltext.]
Towards Universal Speech Discrete Tokens: A Case Study for ASR and TTS
Self-supervised learning (SSL) proficiency in speech-related tasks has driven
research into utilizing discrete tokens for speech tasks like recognition and
translation, which offer lower storage requirements and great potential to
employ natural language processing techniques. However, these studies, mainly
single-task focused, faced challenges like overfitting and performance
degradation in speech recognition tasks, often at the cost of sacrificing
performance in multi-task scenarios. This study presents a comprehensive
comparison and optimization of discrete tokens generated by various leading SSL
models in speech recognition and synthesis tasks. We aim to explore the
universality of speech discrete tokens across multiple speech tasks.
Experimental results demonstrate that discrete tokens achieve comparable
results against systems trained on FBank features in speech recognition tasks
and outperform mel-spectrogram features in speech synthesis in subjective and
objective metrics. These findings suggest that universal discrete tokens have
enormous potential in various speech-related tasks. Our work is open-source and
publicly available to facilitate research in this direction
The Intensity of Diffuse Galactic Emission Reflected by Meteor Trails
We calculate the reflection of diffuse galactic emission by meteor trails and
investigate its potential relationship to Meteor Radio Afterglow (MRA). The
formula to calculate the reflection of diffuse galactic emission is derived
from a simplified case, assuming that the signals are mirrored by the
cylindrical over-dense ionization trail of meteors. The overall observed
reflection is simulated through a ray tracing algorithm together with the
diffuse galactic emission modelled by the GSM sky model. We demonstrate that
the spectrum of the reflected signal is broadband and follows a power law with
a negative spectral index of around -1.3. The intensity of the reflected signal
varies with local sidereal time and the brightness of the meteor and can reach
2000 Jy. These results agree with some previous observations of MRAs.
Therefore, we think that the reflection of galactic emission by meteor trails
can be a possible mechanism causing MRAs, which is worthy of further research.Comment: 15 pages, 10 figures, 2 tables, accepted for publication in MNRAS,
10.1093/mnras/stad342
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