85 research outputs found
Concurrence-Aware Long Short-Term Sub-Memories for Person-Person Action Recognition
Recently, Long Short-Term Memory (LSTM) has become a popular choice to model
individual dynamics for single-person action recognition due to its ability of
modeling the temporal information in various ranges of dynamic contexts.
However, existing RNN models only focus on capturing the temporal dynamics of
the person-person interactions by naively combining the activity dynamics of
individuals or modeling them as a whole. This neglects the inter-related
dynamics of how person-person interactions change over time. To this end, we
propose a novel Concurrence-Aware Long Short-Term Sub-Memories (Co-LSTSM) to
model the long-term inter-related dynamics between two interacting people on
the bounding boxes covering people. Specifically, for each frame, two
sub-memory units store individual motion information, while a concurrent LSTM
unit selectively integrates and stores inter-related motion information between
interacting people from these two sub-memory units via a new co-memory cell.
Experimental results on the BIT and UT datasets show the superiority of
Co-LSTSM compared with the state-of-the-art methods
Training-Free Instance Segmentation from Semantic Image Segmentation Masks
In recent years, the development of instance segmentation has garnered
significant attention in a wide range of applications. However, the training of
a fully-supervised instance segmentation model requires costly both
instance-level and pixel-level annotations. In contrast, weakly-supervised
instance segmentation methods (i.e., with image-level class labels or point
labels) struggle to satisfy the accuracy and recall requirements of practical
scenarios. In this paper, we propose a novel paradigm for instance segmentation
called training-free instance segmentation (TFISeg), which achieves instance
segmentation results from image masks predicted using off-the-shelf semantic
segmentation models. TFISeg does not require training a semantic or/and
instance segmentation model and avoids the need for instance-level image
annotations. Therefore, it is highly efficient. Specifically, we first obtain a
semantic segmentation mask of the input image via a trained semantic
segmentation model. Then, we calculate a displacement field vector for each
pixel based on the segmentation mask, which can indicate representations
belonging to the same class but different instances, i.e., obtaining the
instance-level object information. Finally, instance segmentation results are
obtained after being refined by a learnable category-agnostic object boundary
branch. Extensive experimental results on two challenging datasets and
representative semantic segmentation baselines (including CNNs and
Transformers) demonstrate that TFISeg can achieve competitive results compared
to the state-of-the-art fully-supervised instance segmentation methods without
the need for additional human resources or increased computational costs. The
code is available at: TFISegComment: 14 pages,5 figure
Persistent Josephson tunneling between BiSrCaCuO flakes twisted by 45 across the superconducting dome
There is a heated debate on the Josephson effect in twisted
BiSrCaCuO flakes. Recent experimental results suggest the
presence of either anomalously isotropic pairing or exotic +i-wave
pairing, in addition to the commonly believed -wave one. Here, we address
this controversy by fabricating ultraclean junctions with uncompromised
crystalline quality and stoichiometry at the junction interfaces. In the
optimally doped regime, we obtain prominent Josephson coupling (2-4 mV) in
multiple junctions with the twist angle of 45, in sharp contrast to a
recent report that shows two orders of magnitude suppression around 45
from the value at 0. We further extend this study to the previously
unexplored overdoped regime and observe pronounced Josephson tunneling at
45 together with Josephson diode effect up to 50 K. Our work helps
establish the persistent presence of an isotropic pairing component across the
entire superconducting phase diagram.Comment: 6 pages, 5 figure
Specific frequency bands of amplitude low-frequency fluctuations in memory-related cognitive impairment: predicting Alzheimerās disease
Resting-state functional magnetic resonance imaging was utilized to measure the amplitude low frequency fluctuations (ALFF) in human subjects with Alzheimerās disease (AD) and normal control (NC). Two specific frequency bands (Slow5: 0.01-0.027Hz and Slow4: 0.027-0.073Hz) were analysed in the main cognitive control related four subregions of the right ventral lateral prefrontal cortex (VLPFC), i.e. IFJ, posterior-VLPFC, mid-VLPFC, and anterior-VLPFC. Differences in ALFF values between the AD and the NC group were found throughout the subregions of the right VLPFC. Compared to normal control group, decreased ALFF values were observed in AD patients in the IFJ (in two given frequency bands), and the mid-VLPFC (in Slow5). In contrast, increased ALFF valued were observed in AD patients in the posterior- and anterior-VLPFC (in both Slow5 and Slow4), and also in the mid-VLPFC in Slow4. Moreover, significant ALFF differences between the IFJ and three other subregions of the right VLPFC were found. Furthermore, ALFF values in the right VLPFC showed significant correlations with the time course of disease. Taken together, our findings suggest that AD patients have largely abnormalities in intrinsic neural oscillations which are in line with the AD pathophysiology, and further reveal that the abnormalities are dependent on specific frequency bands. Thus, frequency-domain analyses of the ALFF may provide a useful tool to investigate the AD pathophysiology
Improving Sparse Representation-Based Classification Using Local Principal Component Analysis
Sparse representation-based classification (SRC), proposed by Wright et al.,
seeks the sparsest decomposition of a test sample over the dictionary of
training samples, with classification to the most-contributing class. Because
it assumes test samples can be written as linear combinations of their
same-class training samples, the success of SRC depends on the size and
representativeness of the training set. Our proposed classification algorithm
enlarges the training set by using local principal component analysis to
approximate the basis vectors of the tangent hyperplane of the class manifold
at each training sample. The dictionary in SRC is replaced by a local
dictionary that adapts to the test sample and includes training samples and
their corresponding tangent basis vectors. We use a synthetic data set and
three face databases to demonstrate that this method can achieve higher
classification accuracy than SRC in cases of sparse sampling, nonlinear class
manifolds, and stringent dimension reduction.Comment: Published in "Computational Intelligence for Pattern Recognition,"
editors Shyi-Ming Chen and Witold Pedrycz. The original publication is
available at http://www.springerlink.co
Accelerated Liāŗ Desolvation for Diffusion Booster Enabling LowāTemperature Sulfur Redox Kinetics via Electrocatalytic CarbonāGrazftedāCoP Porous Nanosheets
Lithiumāsulfur (LiāS) batteries are famous for their high energy density and low cost, but prevented by sluggish redox kinetics of sulfur species due to depressive Li ion diffusion kinetics, especially under low-temperature environment. Herein, a combined strategy of electrocatalysis and pore sieving effect is put forward to dissociate the Li+ solvation structure to stimulate the free Li+ diffusion, further improving sulfur redox reaction kinetics. As a protocol, an electrocatalytic porous diffusion-boosted nitrogen-doped carbon-grafted-CoP nanosheet is designed via forming the NCoP active structure to release more free Li+ to react with sulfur species, as fully investigated by electrochemical tests, theoretical simulations and in situ/ex situ characterizations. As a result, the cells with diffusion booster achieve desirable lifespan of 800 cycles at 2 C and excellent rate capability (775 mAh gā1 at 3 C). Impressively, in a condition of high mass loading or low-temperature environment, the cell with 5.7 mg cmā2 stabilizes an areal capacity of 3.2 mAh cmā2 and the charming capacity of 647 mAh gā1 is obtained under 0 Ā°C after 80 cycles, demonstrating a promising route of providing more free Li ions toward practical high-energy LiāS batteries
The 3rd Anti-UAV Workshop & Challenge: Methods and Results
The 3rd Anti-UAV Workshop & Challenge aims to encourage research in
developing novel and accurate methods for multi-scale object tracking. The
Anti-UAV dataset used for the Anti-UAV Challenge has been publicly released.
There are two main differences between this year's competition and the previous
two. First, we have expanded the existing dataset, and for the first time,
released a training set so that participants can focus on improving their
models. Second, we set up two tracks for the first time, i.e., Anti-UAV
Tracking and Anti-UAV Detection & Tracking. Around 76 participating teams from
the globe competed in the 3rd Anti-UAV Challenge. In this paper, we provide a
brief summary of the 3rd Anti-UAV Workshop & Challenge including brief
introductions to the top three methods in each track. The submission
leaderboard will be reopened for researchers that are interested in the
Anti-UAV challenge. The benchmark dataset and other information can be found
at: https://anti-uav.github.io/.Comment: Technical report for 3rd Anti-UAV Workshop and Challenge. arXiv admin
note: text overlap with arXiv:2108.0990
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