108 research outputs found
BEVStereo++: Accurate Depth Estimation in Multi-view 3D Object Detection via Dynamic Temporal Stereo
Bounded by the inherent ambiguity of depth perception, contemporary
multi-view 3D object detection methods fall into the performance bottleneck.
Intuitively, leveraging temporal multi-view stereo (MVS) technology is the
natural knowledge for tackling this ambiguity. However, traditional attempts of
MVS has two limitations when applying to 3D object detection scenes: 1) The
affinity measurement among all views suffers expensive computational cost; 2)
It is difficult to deal with outdoor scenarios where objects are often mobile.
To this end, we propose BEVStereo++: by introducing a dynamic temporal stereo
strategy, BEVStereo++ is able to cut down the harm that is brought by
introducing temporal stereo when dealing with those two scenarios. Going one
step further, we apply Motion Compensation Module and long sequence Frame
Fusion to BEVStereo++, which shows further performance boosting and error
reduction. Without bells and whistles, BEVStereo++ achieves
state-of-the-art(SOTA) on both Waymo and nuScenes dataset
Composition Comparison between ICMEs from Active Regions and Quiet-Sun Regions
The composition, including the ionic charge states and elemental abundances
of heavy elements, within interplanetary coronal mass ejections (ICMEs) has
tight correlations with their source regions and eruption processes. This can
help analyze the eruption mechanisms and plasma origins of CMEs, and deepen our
understanding of energetic solar activities. The active regions and quiet-Sun
regions have different physical properties, thus from a statistical point of
view, ICMEs originating from the two types of regions should exhibit different
compositional characteristics. To demonstrate the differences comprehensively,
we conduct survey studies on the ionic charge states of five elements (Mg, Fe,
Si, C, and O) and the relative abundances of six elements (Mg/O, Fe/O, Si/O,
C/O, Ne/O, and He/O) within ICMEs from 1998 February to 2011 August through the
data of advanced composition explorer. The results show that ICMEs from active
regions have higher ionic charge states and relative abundances than those from
quiet-Sun regions. For the active-region ICMEs, we further analyze the
relations between their composition and flare class, and find a positive
relationship between them, i.e., the higher classes of the associated flares,
the larger means of ionic charge states and relative abundances (except the
C/O) within ICMEs. As more (less) fractions of ICMEs originate from active
regions around solar maximum (minimum), and active-region ICMEs usually are
associated with higher-class flares, our studies might answer why ICME
composition measured near 1 au exhibits the solar cycle dependence.Comment: 13 pages, 4 figure
Epidemiological Trends in Cardiovascular Disease Mortality Attributable to Modifiable Risk Factors and Its Association with Sociodemographic Transitions across BRICS-Plus Countries
BRICS-Plus countries (Brazil, Russia, India, China, South Africa, and 30 other countries) is a group of 35 countries with emerging economies making up more than half of the world's population. We explored epidemiological trends of cardiovascular disease (CVD) mortality attributable to modifiable risk factors and its association with period and birth cohort effects and sociodemographic index (SDI) across BRICS-Plus countries by using joinpoint regression and age-period-cohort modeling from 1990 to 2019. Between 1990 and 2019, the all-ages CVD deaths increased by 85.2% (6.1 million to 11.3 million) across BRICS-Plus countries. The CVD age-standardized mortality rate attributable to dietary risks and smoking significantly decreased across BRICS-Plus countries, with some exceptions. However, four-fifths of BRICS-Plus countries observed a remarkable increasing trend of high body mass-index (BMI)-related CVD deaths, in particular, among younger adults (25-49 years). Early birth cohorts and individuals aged greater than 50 years showed a higher risk of CVD mortality. Both the China-ASEAN FTA and Mercosur regions stand out for their successful sociodemographic transition, with a significant reduction in CVD mortality over the study period. Singapore and Brazil achieved great progress in CVD mortality reduction and the other BRICS-Plus countries should follow their lead in adopting public health policies and initiatives into practice
DBQ-SSD: Dynamic Ball Query for Efficient 3D Object Detection
Many point-based 3D detectors adopt point-feature sampling strategies to drop
some points for efficient inference. These strategies are typically based on
fixed and handcrafted rules, making difficult to handle complicated scenes.
Different from them, we propose a Dynamic Ball Query (DBQ) network to
adaptively select a subset of input points according to the input features, and
assign the feature transform with suitable receptive field for each selected
point. It can be embedded into some state-of-the-art 3D detectors and trained
in an end-to-end manner, which significantly reduces the computational cost.
Extensive experiments demonstrate that our method can reduce latency by 30%-60%
on KITTI and Waymo datasets. Specifically, the inference speed of our detector
can reach 162 FPS and 30 FPS with negligible performance degradation on KITTI
and Waymo datasets, respectively
Physiological Ischemic Training Promotes Brain Collateral Formation and Improves Functions in Patients with Acute Cerebral Infarction
Objectives: To observe the effectiveness and mechanisms of physiological ischemic training (PIT) on brain cerebral collateral formation and functional recovery in patients with acute cerebral infarction.Methods: 20 eligible patients with acute cerebral infarction were randomly assigned to either PIT group (n = 10) or Control group (n = 10). Both groups received 4 weeks of routine rehabilitation therapy, while an additional session of PIT, which consisted of 10 times of maximal voluntary isometric handgrip for 1 min followed by 1 min rest, was prescribed for patients in the PIT groups. Each patient was trained with four sections a day and 5 days a week for 4 weeks. The Fugl-Meyer Assessment (FMA), the Modified Barthel Index (MBI), and the short-form 36-item health survey questionnaire (SF-36) were applied for the evaluation of motor impairment, activity of daily living, and quality of life at the baseline and endpoint. MRI was applied to detect the collateral formation in the brain. The concentration of vascular endothelial growth factor (VEGF) and endothelial progenitor cells (EPCs) number in plasma were also tested at the endpoint.Results: Demographic data were consistent between experimental groups. At the endpoint, the scores of the FMA, MBI, and SF-36 were significantly higher than that at baseline. As compared to the Control group, the score of FMA and SF-36 in PIT group was significantly higher, while no significant difference was detected between groups in terms of MBI. Both groups had significantly higher cerebral blood flow (CBF) level at endpoint as compared to that at baseline. Moreover, the CBF level was even higher in the PIT group as compared to that in the Control group after 4 weeks of training. The same situations were also found in the plasma VEGF and EPCs assessment. In addition, positive correlations were found between FMA score and CBF level (r = 0.686, p < 0.01), CBF level and VEGF concentration (r = 0.675, p < 0.01), and VEGF concentration and EPC number (r = 0.722, p < 0.01).Conclusion: PIT may be effective in increasing the expression of VEGF and recruitment of EPCs and in turn promote the formation of brain collateral circulation. The positive correlations may demonstrate a potential association between biological and functional parameters, and PIT may be able to improve the motor function, activity of daily living, and quality of life in patients with stroke.Interdisciplinary Division of Biomedical Engineerin
DreamLLM: Synergistic Multimodal Comprehension and Creation
This paper presents DreamLLM, a learning framework that first achieves
versatile Multimodal Large Language Models (MLLMs) empowered with frequently
overlooked synergy between multimodal comprehension and creation. DreamLLM
operates on two fundamental principles. The first focuses on the generative
modeling of both language and image posteriors by direct sampling in the raw
multimodal space. This approach circumvents the limitations and information
loss inherent to external feature extractors like CLIP, and a more thorough
multimodal understanding is obtained. Second, DreamLLM fosters the generation
of raw, interleaved documents, modeling both text and image contents, along
with unstructured layouts. This allows DreamLLM to learn all conditional,
marginal, and joint multimodal distributions effectively. As a result, DreamLLM
is the first MLLM capable of generating free-form interleaved content.
Comprehensive experiments highlight DreamLLM's superior performance as a
zero-shot multimodal generalist, reaping from the enhanced learning synergy.Comment: see project page at https://dreamllm.github.io
Search for light dark matter from atmosphere in PandaX-4T
We report a search for light dark matter produced through the cascading decay
of mesons, which are created as a result of inelastic collisions between
cosmic rays and Earth's atmosphere. We introduce a new and general framework,
publicly accessible, designed to address boosted dark matter specifically, with
which a full and dedicated simulation including both elastic and quasi-elastic
processes of Earth attenuation effect on the dark matter particles arriving at
the detector is performed. In the PandaX-4T commissioning data of 0.63
tonneyear exposure, no significant excess over background is observed.
The first constraints on the interaction between light dark matter generated in
the atmosphere and nucleus through a light scalar mediator are obtained. The
lowest excluded cross-section is set at for
dark matter mass of MeV and mediator mass of 300 MeV. The
lowest upper limit of to dark matter decay branching ratio is
A Search for Light Fermionic Dark Matter Absorption on Electrons in PandaX-4T
We report a search on a sub-MeV fermionic dark matter absorbed by electrons
with an outgoing active neutrino using the 0.63 tonne-year exposure collected
by PandaX-4T liquid xenon experiment. No significant signals are observed over
the expected background. The data are interpreted into limits to the effective
couplings between such dark matter and electrons. For axial-vector or vector
interactions, our sensitivity is competitive in comparison to existing
astrophysical bounds on the decay of such dark matter into photon final states.
In particular, we present the first direct detection limits for an axial-vector
(vector) interaction which are the strongest in the mass range from 25 to 45
(35 to 50) keV/c
Tirofiban for Stroke without Large or Medium-Sized Vessel Occlusion
The effects of the glycoprotein IIb/IIIa receptor inhibitor tirofiban in patients with acute ischemic stroke but who have no evidence of complete occlusion of large or medium-sized vessels have not been extensively studied. In a multicenter trial in China, we enrolled patients with ischemic stroke without occlusion of large or medium-sized vessels and with a National Institutes of Health Stroke Scale score of 5 or more and at least one moderately to severely weak limb. Eligible patients had any of four clinical presentations: ineligible for thrombolysis or thrombectomy and within 24 hours after the patient was last known to be well; progression of stroke symptoms 24 to 96 hours after onset; early neurologic deterioration after thrombolysis; or thrombolysis with no improvement at 4 to 24 hours. Patients were assigned to receive intravenous tirofiban (plus oral placebo) or oral aspirin (100 mg per day, plus intravenous placebo) for 2 days; all patients then received oral aspirin until day 90. The primary efficacy end point was an excellent outcome, defined as a score of 0 or 1 on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) at 90 days. Secondary end points included functional independence at 90 days and a quality-of-life score. The primary safety end points were death and symptomatic intracranial hemorrhage. A total of 606 patients were assigned to the tirofiban group and 571 to the aspirin group. Most patients had small infarctions that were presumed to be atherosclerotic. The percentage of patients with a score of 0 or 1 on the modified Rankin scale at 90 days was 29.1% with tirofiban and 22.2% with aspirin (adjusted risk ratio, 1.26; 95% confidence interval, 1.04 to 1.53, P = 0.02). Results for secondary end points were generally not consistent with the results of the primary analysis. Mortality was similar in the two groups. The incidence of symptomatic intracranial hemorrhage was 1.0% in the tirofiban group and 0% in the aspirin group. In this trial involving heterogeneous groups of patients with stroke of recent onset or progression of stroke symptoms and nonoccluded large and medium-sized cerebral vessels, intravenous tirofiban was associated with a greater likelihood of an excellent outcome than low-dose aspirin. Incidences of intracranial hemorrhages were low but slightly higher with tirofiban
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