57 research outputs found
Interpretable and Efficient Beamforming-Based Deep Learning for Single Snapshot DOA Estimation
We introduce an interpretable deep learning approach for direction of arrival
(DOA) estimation with a single snapshot. Classical subspace-based methods like
MUSIC and ESPRIT use spatial smoothing on uniform linear arrays for single
snapshot DOA estimation but face drawbacks in reduced array aperture and
inapplicability to sparse arrays. Single-snapshot methods such as compressive
sensing and iterative adaptation approach (IAA) encounter challenges with high
computational costs and slow convergence, hampering real-time use. Recent deep
learning DOA methods offer promising accuracy and speed. However, the practical
deployment of deep networks is hindered by their black-box nature. To address
this, we propose a deep-MPDR network translating minimum power distortionless
response (MPDR)-type beamformer into deep learning, enhancing generalization
and efficiency. Comprehensive experiments conducted using both simulated and
real-world datasets substantiate its dominance in terms of inference time and
accuracy in comparison to conventional methods. Moreover, it excels in terms of
efficiency, generalizability, and interpretability when contrasted with other
deep learning DOA estimation networks.Comment: 10 pages, 10 figure
Deep Learning based 3D Segmentation: A Survey
3D object segmentation is a fundamental and challenging problem in computer
vision with applications in autonomous driving, robotics, augmented reality and
medical image analysis. It has received significant attention from the computer
vision, graphics and machine learning communities. Traditionally, 3D
segmentation was performed with hand-crafted features and engineered methods
which failed to achieve acceptable accuracy and could not generalize to
large-scale data. Driven by their great success in 2D computer vision, deep
learning techniques have recently become the tool of choice for 3D segmentation
tasks as well. This has led to an influx of a large number of methods in the
literature that have been evaluated on different benchmark datasets. This paper
provides a comprehensive survey of recent progress in deep learning based 3D
segmentation covering over 150 papers. It summarizes the most commonly used
pipelines, discusses their highlights and shortcomings, and analyzes the
competitive results of these segmentation methods. Based on the analysis, it
also provides promising research directions for the future.Comment: Under review of ACM Computing Surveys, 36 pages, 10 tables, 9 figure
First Place Solution to the CVPR'2023 AQTC Challenge: A Function-Interaction Centric Approach with Spatiotemporal Visual-Language Alignment
Affordance-Centric Question-driven Task Completion (AQTC) has been proposed
to acquire knowledge from videos to furnish users with comprehensive and
systematic instructions. However, existing methods have hitherto neglected the
necessity of aligning spatiotemporal visual and linguistic signals, as well as
the crucial interactional information between humans and objects. To tackle
these limitations, we propose to combine large-scale pre-trained
vision-language and video-language models, which serve to contribute stable and
reliable multimodal data and facilitate effective spatiotemporal visual-textual
alignment. Additionally, a novel hand-object-interaction (HOI) aggregation
module is proposed which aids in capturing human-object interaction
information, thereby further augmenting the capacity to understand the
presented scenario. Our method achieved first place in the CVPR'2023 AQTC
Challenge, with a Recall@1 score of 78.7\%. The code is available at
https://github.com/tomchen-ctj/CVPR23-LOVEU-AQTC.Comment: Winner of CVPR2023 Long-form Video Understanding and Generation
Challenge (Track 3
Giant pressure-enhancement of multiferroicity in CuBr2
Type-II multiferroic materials, in which ferroelectric polarization is
induced by inversion non-symmetric magnetic order, promise new and highly
efficient multifunctional applications based on the mutual control of magnetic
and electric properties. Although this phenomenon has to date been limited to
low temperatures, here we report a giant pressure-dependence of the
multiferroic critical temperature in CuBr. At 4.5 GPa, is
enhanced from 73.5 to 162 K, to our knowledge the highest value yet reported
for a non-oxide type-II multiferroic. This growth shows no sign of saturating
and the dielectric loss remains small under these high pressures. We establish
the structure under pressure and demonstrate a 60\% increase in the two-magnon
Raman energy scale up to 3.6 GPa. First-principles structural and magnetic
energy calculations provide a quantitative explanation in terms of dramatically
pressure-enhanced interactions between CuBr chains. These large,
pressure-tuned magnetic interactions motivate structural control in cuprous
halides as a route to applied high-temperature multiferroicity.Comment: 10 pages, 6 figure
Application of multivariate linear methods to the development of a stratified system in Block II of Area A
This study is a numerical simulation study of different stratigraphic development schemes for three encrypted well networks based on historical fitting by establishing a fine geological model for Block II of Area A. The relationship between reservoir physical parameters and recovery rates for different stratigraphic combinations is obtained by applying multiple linearity regression methods to guide the delineation of stratigraphic development sections in multi-layered non-homogeneous reservoirs
Characterization of microbial community in industrial bioleaching heap of copper sulfide ore at Monywa mine, Myanmar
Microbial communities and activities in multi-lift bioleaching heap of copper sulfide ore were investigated at Monywa copper mine, Myanmar. The high-throughput sequencing method revealed a microbial community dominated by archaeal Ferroplasma (about 70%), rather than more commonly reported genera of Acidithiobacillus and Leptospirillum (together about 25% in Monywa heap). Multi-lift stacking operation without heap aeration resulted in low oxygen concentrations in the heaps (leachate oxygen concentration of 0.35 mg L-1 to 0.68 mg L-1). Therefore, low oxygen concentrations, high organic matter concentrations and moderate temperature in the heaps favored the growth of versatile Ferroplasma which can both undergo autotrophic and heterotrophic growth. Total cell number in the irrigation solution and leachate was in the range of 4.86-8.80 x 106 mL(-1), and the detected microbes in ore residues and leaching solutions were mainly those with iron-oxidizing ability. Their iron-oxidizing rate showed highest at the temperature of 35 degrees C, while in heaps may be limited by the low oxygen supply. Monywa bioleaching system with the above mentioned microbial community and activity formed a leaching solution of low redox potential, resulting in appropriate pyrite oxidation during chalcocite dissolution, thus helped maintain relatively stable acid and iron concentration in the cycling leaching solution. This study explained the formation of the microbial community and activity in Monywa heap leaching, linking to its heap physical and chemical conditions, and suggested that the role of Ferroplasma in bioleaching system may have been overlooked previously, especially in oxygen-limited bioleaching heaps. (C) 2016 Elsevier B.V. All rights reserved.</p
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