772 research outputs found
A Novel Method of the Generalized Interval-Valued Fuzzy Rough Approximation Operators
Rough set theory is a suitable tool for dealing with the imprecision, uncertainty, incompleteness, and vagueness of knowledge. In this paper, new lower and upper approximation operators for generalized fuzzy rough sets are constructed, and their definitions are expanded to the interval-valued environment. Furthermore, the properties of this type of rough sets are analyzed. These operators are shown to be equivalent to the generalized interval fuzzy rough approximation operators introduced by Dubois, which are determined by any interval-valued fuzzy binary relation expressed in a generalized approximation space. Main properties of these operators are discussed under different interval-valued fuzzy binary relations, and the illustrative examples are given to demonstrate the main features of the proposed operators
Neural-Network-Driven Method for Optimal Path Planning via High-Accuracy Region Prediction
Sampling-based path planning algorithms suffer from heavy reliance on uniform
sampling, which accounts for unreliable and time-consuming performance,
especially in complex environments. Recently, neural-network-driven methods
predict regions as sampling domains to realize a non-uniform sampling and
reduce calculation time. However, the accuracy of region prediction hinders
further improvement. We propose a sampling-based algorithm, abbreviated to
Region Prediction Neural Network RRT* (RPNN-RRT*), to rapidly obtain the
optimal path based on a high-accuracy region prediction. First, we implement a
region prediction neural network (RPNN), to predict accurate regions for the
RPNN-RRT*. A full-layer channel-wise attention module is employed to enhance
the feature fusion in the concatenation between the encoder and decoder.
Moreover, a three-level hierarchy loss is designed to learn the pixel-wise,
map-wise, and patch-wise features. A dataset, named Complex Environment Motion
Planning, is established to test the performance in complex environments.
Ablation studies and test results show that a high accuracy of 89.13% is
achieved by the RPNN for region prediction, compared with other region
prediction models. In addition, the RPNN-RRT* performs in different complex
scenarios, demonstrating significant and reliable superiority in terms of the
calculation time, sampling efficiency, and success rate for optimal path
planning.Comment: 9 pages, 8 figure
TransY-Net:Learning Fully Transformer Networks for Change Detection of Remote Sensing Images
In the remote sensing field, Change Detection (CD) aims to identify and
localize the changed regions from dual-phase images over the same places.
Recently, it has achieved great progress with the advances of deep learning.
However, current methods generally deliver incomplete CD regions and irregular
CD boundaries due to the limited representation ability of the extracted visual
features. To relieve these issues, in this work we propose a novel
Transformer-based learning framework named TransY-Net for remote sensing image
CD, which improves the feature extraction from a global view and combines
multi-level visual features in a pyramid manner. More specifically, the
proposed framework first utilizes the advantages of Transformers in long-range
dependency modeling. It can help to learn more discriminative global-level
features and obtain complete CD regions. Then, we introduce a novel pyramid
structure to aggregate multi-level visual features from Transformers for
feature enhancement. The pyramid structure grafted with a Progressive Attention
Module (PAM) can improve the feature representation ability with additional
inter-dependencies through spatial and channel attentions. Finally, to better
train the whole framework, we utilize the deeply-supervised learning with
multiple boundary-aware loss functions. Extensive experiments demonstrate that
our proposed method achieves a new state-of-the-art performance on four optical
and two SAR image CD benchmarks. The source code is released at
https://github.com/Drchip61/TransYNet.Comment: This work is accepted by TGRS2023. It is an extension of our ACCV2022
paper and arXiv:2210.0075
Co3O4@CoS core-shell nanosheets on carbon cloth for high performance supercapacitor electrodes
In this work, a two-step electrodeposition strategy is developed for the synthesis of core-shell Co3O4@CoS nanosheet arrays on carbon cloth (CC) for supercapacitor applications. Porous Co3O4 nanosheet arrays are first directly grown on CC by electrodeposition, followed by the coating of a thin layer of CoS on the surface of Co3O4 nanosheets via the secondary electrodeposition. The morphology control of the ternary composites can be easily achieved by altering the number of cyclic voltammetry (CV) cycles of CoS deposition. Electrochemical performance of the composite electrodes was evaluated by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy techniques. The results demonstrate that the Co3O4@CoS/CC with 4 CV cycles of CoS deposition possesses the largest specific capacitance 887.5 F·g-1 at a scan rate of 10 mV·s-1 (764.2 F·g-1 at a current density of 1.0 A·g-1), and excellent cycling stability (78.1% capacitance retention) at high current density of 5.0 A·g-1 after 5000 cycles. The porous nanostructures on CC not only provide large accessible surface area for fast ions diffusion, electron transport and efficient utilization of active CoS and Co3O4, but also reduce the internal resistance of electrodes, which leads to superior electrochemical performance of Co3O4@CoS/CC composite at 4 cycles of CoS deposition. © 2017 by the authors.National Natural Science Foundation of China [21371057]; International Science and Technology Cooperation Program of China [2016YFE0131200, 2015DFA51220]; International Cooperation Project of Shanghai Municipal Science and Technology Committee [15520721100
Hierarchical Semi-Implicit Variational Inference with Application to Diffusion Model Acceleration
Semi-implicit variational inference (SIVI) has been introduced to expand the
analytical variational families by defining expressive semi-implicit
distributions in a hierarchical manner. However, the single-layer architecture
commonly used in current SIVI methods can be insufficient when the target
posterior has complicated structures. In this paper, we propose hierarchical
semi-implicit variational inference, called HSIVI, which generalizes SIVI to
allow more expressive multi-layer construction of semi-implicit distributions.
By introducing auxiliary distributions that interpolate between a simple base
distribution and the target distribution, the conditional layers can be trained
by progressively matching these auxiliary distributions one layer after
another. Moreover, given pre-trained score networks, HSIVI can be used to
accelerate the sampling process of diffusion models with the score matching
objective. We show that HSIVI significantly enhances the expressiveness of SIVI
on several Bayesian inference problems with complicated target distributions.
When used for diffusion model acceleration, we show that HSIVI can produce high
quality samples comparable to or better than the existing fast diffusion model
based samplers with a small number of function evaluations on various datasets.Comment: 25 pages, 13 figures, NeurIPS 202
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