21 research outputs found
STGlow: A Flow-based Generative Framework with Dual Graphormer for Pedestrian Trajectory Prediction
Pedestrian trajectory prediction task is an essential component of
intelligent systems, and its applications include but are not limited to
autonomous driving, robot navigation, and anomaly detection of monitoring
systems. Due to the diversity of motion behaviors and the complex social
interactions among pedestrians, accurately forecasting the future trajectory of
pedestrians is challenging. Existing approaches commonly adopt GANs or CVAEs to
generate diverse trajectories. However, GAN-based methods do not directly model
data in a latent space, which makes them fail to have full support over the
underlying data distribution; CVAE-based methods optimize a lower bound on the
log-likelihood of observations, causing the learned distribution to deviate
from the underlying distribution. The above limitations make existing
approaches often generate highly biased or unnatural trajectories. In this
paper, we propose a novel generative flow based framework with dual graphormer
for pedestrian trajectory prediction (STGlow). Different from previous
approaches, our method can more accurately model the underlying data
distribution by optimizing the exact log-likelihood of motion behaviors.
Besides, our method has clear physical meanings to simulate the evolution of
human motion behaviors, where the forward process of the flow gradually
degrades the complex motion behavior into a simple behavior, while its reverse
process represents the evolution of a simple behavior to the complex motion
behavior. Further, we introduce a dual graphormer combining with the graph
structure to more adequately model the temporal dependencies and the mutual
spatial interactions. Experimental results on several benchmarks demonstrate
that our method achieves much better performance compared to previous
state-of-the-art approaches.Comment: 12 pages, 8 figure
Temporal Pyramid Network for Pedestrian Trajectory Prediction with Multi-Supervision
Predicting human motion behavior in a crowd is important for many
applications, ranging from the natural navigation of autonomous vehicles to
intelligent security systems of video surveillance. All the previous works
model and predict the trajectory with a single resolution, which is rather
inefficient and difficult to simultaneously exploit the long-range information
(e.g., the destination of the trajectory), and the short-range information
(e.g., the walking direction and speed at a certain time) of the motion
behavior. In this paper, we propose a temporal pyramid network for pedestrian
trajectory prediction through a squeeze modulation and a dilation modulation.
Our hierarchical framework builds a feature pyramid with increasingly richer
temporal information from top to bottom, which can better capture the motion
behavior at various tempos. Furthermore, we propose a coarse-to-fine fusion
strategy with multi-supervision. By progressively merging the top coarse
features of global context to the bottom fine features of rich local context,
our method can fully exploit both the long-range and short-range information of
the trajectory. Experimental results on several benchmarks demonstrate the
superiority of our method.Comment: 9 pages, 5 figure
Indocyanine Green Loaded Reduced Graphene Oxide for In Vivo Photoacoustic/Fluorescence Dual-Modality Tumor Imaging
Multimodality imaging based on multifunctional nanocomposites holds great promise to fundamentally augment the capability of biomedical imaging. Specifically, photoacoustic and fluorescence dual-modality imaging is gaining much interest because of their non-invasiveness and the complementary nature of the two modalities in terms of imaging resolution, depth, sensitivity, and speed. Herein, using a green and facile method, we synthesize indocyanine green (ICG) loaded, polyethylene glycol (PEG) ylated, reduced nano-graphene oxide nanocomposite (rNGO-PEG/ICG) as a new type of fluorescence and photoacoustic dual-modality imaging contrast. The nanocomposite is shown to have minimal toxicity and excellent photoacoustic/fluorescence signals both in vitro and in vivo. Compared with free ICG, the nanocomposite is demonstrated to possess greater stability, longer blood circulation time, and superior passive tumor targeting capability. In vivo study shows that the circulation time of rNGO-PEG/ICG in the mouse body can sustain up to 6 h upon intravenous injection; while after 1 day, no obvious accumulation of rNGO-PEG/ICG is found in any major organs except the tumor regions. The demonstrated high fluorescence/photoacoustic dual contrasts, together with its low toxicity and excellent circulation life time, suggest that the synthesized rNGO-PEG/ICG can be a promising candidate for further translational studies on both the early diagnosis and image-guided therapy/surgery of cancer.11248Ysciescopu
Indocyanine Green Loaded Reduced Graphene Oxide for In Vivo Photoacoustic/Fluorescence Dual-Modality Tumor Imaging
Tumor-Targeted Fluorescence Imaging and Mechanisms of Tumor Cell-Derived Carbon Nanodots
An ideal cancer diagnostic probe should possess precise tumor-targeted accumulation with negligible sojourn in normal tissues. Herein, tumor cell-derived carbon nanodots (C-CNDU87 and C-CNDHepG2) about 3~7 nm were prepared by a solvothermal method with stable fluorescence and negligible cytotoxicity. More interestingly, due to the differences in gene expression of cancers, C-CND structurally mimicked the corresponding precursors during carbonization in which carbon nanodots were functionalized with α-amino and carboxyl groups with different densities on their edges. With inherent homology and homing effect, C-CND were highly enriched in precursor tumor tissues. Mechanistic studies showed that under the mediation of the original configuration of α-amino and carboxyl groups, C-CND specifically bound to the large neutral amino acid transporter 1 (LAT1, overexpressed in cancer cells), achieving specific tumor fluorescence imaging. This work provided a new vision about tumor cell architecture-mimicked carbon nanodots for tumor-targeted fluorescence imaging
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Bivariate graph showing size distribution of Tuzoia spp. from the Balang and Kaili biotas (T. sinensis Pan, 1957 in purple; T. lazizhaiensis sp. nov. in blue, and T. bispinosa Yuan & Zhao, 1999 in red); valve length (L) on x-axis, and valve height (H) on y-axis
Performance of one-way carsharing systems under combined strategy of pricing and relocations
A bilevel nonlinear mathematical programing model is formulated to determine the optimal pricing and operator-based relocations in a one-way station-based carsharing system in competition with private cars. In the upper level, the carsharing operator determines the vehicle fleet, prices, and relocation operations with the objective of maximizing profits, considering the potential reaction of travelers. In the lower level, travelers choose travel modes from a cost-minimization perspective. Travel utilities are calculated through a logit model. The KarushāKuhnāTucker conditions are used to transform the bilevel model into a single-level model and then a genetic algorithm is proposed to solve it. Computational tests in four different scenarios show the combined strategy is the best one. The four scenarios are base, relocations, dynamic pricing, and a combination of relocations and pricing separately. The combined strategy can make the best trade-offs between the operatorās profit and the travelersā cost.Accepted author manuscriptTransport and Plannin