766 research outputs found
Uniqueness of iterative positive solutions for the singular infinite-point p-Laplacian fractional differential system via sequential technique
By sequential techniques and mixed monotone operator, the uniqueness of positive solution for singular p-Laplacian fractional differential system with infinite-point boundary conditions is obtained. Green's function is derived, and some useful properties of Green' function are obtained. Based on these new properties, the existence of unique positive solutions is established, moreover, an iterative sequence and a convergence rate are given, which are important for practical application, and an example is given to demonstrate the validity of our main results
Existence of multiple positive solutions for a class of infinite-point singular p-Laplacian fractional differential equation with singular source terms
Based on properties of Green’s function and by Avery–Peterson fixed point theorem, the existence of multiple positive solutions are obtained for singular p-Laplacian fractional differential equation with infinite-point boundary conditions, and an example is given to demonstrate the validity of our main results
DoSTra: Discovering common behaviors of objects using the duration of staying on each location of trajectories
Since semantic trajectories can discover more semantic meanings of a user\u27s interests without geographic restrictions, research on semantic trajectories has attracted a lot of attentions in recent years. Most existing work discover the similar behavior of moving objects through analysis of their semantic trajectory pattern, that is, sequences of locations. However, this kind of trajectories without considering the duration of staying on a location limits wild applications. For example, Tom and Anne have a common pattern of Home→Restaurant → Company → Restaurant, but they are not similar, since Tom works at Restaurant, sends snack to someone at Company and return to Restaurant while Anne has breakfast at Restaurant, works at Company and has lunch at Restaurant. If we consider duration of staying on each location we can easily to differentiate their behaviors. In this paper, we propose a novel approach for discovering common behaviors by considering the duration of staying on each location of trajectories (DoSTra). Our approach can be used to detect the group that has similar lifestyle, habit or behavior patterns and predict the future locations of moving objects. We evaluate the experiment based on synthetic dataset, which demonstrates the high effectiveness and efficiency of the proposed method
PDPP:Projected Diffusion for Procedure Planning in Instructional Videos
In this paper, we study the problem of procedure planning in instructional
videos, which aims to make goal-directed plans given the current visual
observations in unstructured real-life videos. Previous works cast this problem
as a sequence planning problem and leverage either heavy intermediate visual
observations or natural language instructions as supervision, resulting in
complex learning schemes and expensive annotation costs. In contrast, we treat
this problem as a distribution fitting problem. In this sense, we model the
whole intermediate action sequence distribution with a diffusion model (PDPP),
and thus transform the planning problem to a sampling process from this
distribution. In addition, we remove the expensive intermediate supervision,
and simply use task labels from instructional videos as supervision instead.
Our model is a U-Net based diffusion model, which directly samples action
sequences from the learned distribution with the given start and end
observations. Furthermore, we apply an efficient projection method to provide
accurate conditional guides for our model during the learning and sampling
process. Experiments on three datasets with different scales show that our PDPP
model can achieve the state-of-the-art performance on multiple metrics, even
without the task supervision. Code and trained models are available at
https://github.com/MCG-NJU/PDPP.Comment: Accepted as a highlight paper at CVPR 202
StageInteractor: Query-based Object Detector with Cross-stage Interaction
Previous object detectors make predictions based on dense grid points or
numerous preset anchors. Most of these detectors are trained with one-to-many
label assignment strategies. On the contrary, recent query-based object
detectors depend on a sparse set of learnable queries and a series of decoder
layers. The one-to-one label assignment is independently applied on each layer
for the deep supervision during training. Despite the great success of
query-based object detection, however, this one-to-one label assignment
strategy demands the detectors to have strong fine-grained discrimination and
modeling capacity. To solve the above problems, in this paper, we propose a new
query-based object detector with cross-stage interaction, coined as
StageInteractor. During the forward propagation, we come up with an efficient
way to improve this modeling ability by reusing dynamic operators with
lightweight adapters. As for the label assignment, a cross-stage label assigner
is applied subsequent to the one-to-one label assignment. With this assigner,
the training target class labels are gathered across stages and then
reallocated to proper predictions at each decoder layer. On MS COCO benchmark,
our model improves the baseline by 2.2 AP, and achieves 44.8 AP with ResNet-50
as backbone, 100 queries and 12 training epochs. With longer training time and
300 queries, StageInteractor achieves 51.1 AP and 52.2 AP with ResNeXt-101-DCN
and Swin-S, respectively
Memory-and-Anticipation Transformer for Online Action Understanding
Most existing forecasting systems are memory-based methods, which attempt to
mimic human forecasting ability by employing various memory mechanisms and have
progressed in temporal modeling for memory dependency. Nevertheless, an obvious
weakness of this paradigm is that it can only model limited historical
dependence and can not transcend the past. In this paper, we rethink the
temporal dependence of event evolution and propose a novel
memory-anticipation-based paradigm to model an entire temporal structure,
including the past, present, and future. Based on this idea, we present
Memory-and-Anticipation Transformer (MAT), a memory-anticipation-based
approach, to address the online action detection and anticipation tasks. In
addition, owing to the inherent superiority of MAT, it can process online
action detection and anticipation tasks in a unified manner. The proposed MAT
model is tested on four challenging benchmarks TVSeries, THUMOS'14, HDD, and
EPIC-Kitchens-100, for online action detection and anticipation tasks, and it
significantly outperforms all existing methods. Code is available at
https://github.com/Echo0125/Memory-and-Anticipation-Transformer.Comment: ICCV 2023 Camera Read
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