377 research outputs found
Generative Models for Novelty Detection Applications in abnormal event and situational changedetection from data series
Novelty detection is a process for distinguishing the observations that differ in some respect
from the observations that the model is trained on. Novelty detection is one of the fundamental
requirements of a good classification or identification system since sometimes the
test data contains observations that were not known at the training time. In other words, the
novelty class is often is not presented during the training phase or not well defined.
In light of the above, one-class classifiers and generative methods can efficiently model
such problems. However, due to the unavailability of data from the novelty class, training
an end-to-end model is a challenging task itself. Therefore, detecting the Novel classes in
unsupervised and semi-supervised settings is a crucial step in such tasks.
In this thesis, we propose several methods to model the novelty detection problem in
unsupervised and semi-supervised fashion. The proposed frameworks applied to different
related applications of anomaly and outlier detection tasks. The results show the superior of
our proposed methods in compare to the baselines and state-of-the-art methods
A Survey on Few-Shot Class-Incremental Learning
Large deep learning models are impressive, but they struggle when real-time data is not available. Few-shot class-incremental learning (FSCIL) poses a significant challenge for deep neural networks to learn new tasks from just a few labeled samples without forgetting the previously learned ones. This setup can easily leads to catastrophic forgetting and overfitting problems, severely affecting model performance. Studying FSCIL helps overcome deep learning model limitations on data volume and acquisition time, while improving practicality and adaptability of machine learning models. This paper provides a comprehensive survey on FSCIL. Unlike previous surveys, we aim to synthesize few-shot learning and incremental learning, focusing on introducing FSCIL from two perspectives, while reviewing over 30 theoretical research studies and more than 20 applied research studies. From the theoretical perspective, we provide a novel categorization approach that divides the field into five subcategories, including traditional machine learning methods, meta learning-based methods, feature and feature space-based methods, replay-based methods, and dynamic network structure-based methods. We also evaluate the performance of recent theoretical research on benchmark datasets of FSCIL. From the application perspective, FSCIL has achieved impressive achievements in various fields of computer vision such as image classification, object detection, and image segmentation, as well as in natural language processing and graph. We summarize the important applications. Finally, we point out potential future research directions, including applications, problem setups, and theory development. Overall, this paper offers a comprehensive analysis of the latest advances in FSCIL from a methodological, performance, and application perspective
Adaptive detection and tracking using multimodal information
This thesis describes work on fusing data from multiple sources of information, and focuses on two main areas: adaptive detection and adaptive object tracking in automated vision scenarios. The work on adaptive object detection explores a new paradigm in dynamic parameter selection, by selecting thresholds for object detection to maximise agreement between pairs of sources. Object tracking, a complementary technique to object detection, is also explored in a multi-source context and an efficient framework for robust tracking, termed the Spatiogram Bank tracker, is proposed as a means to overcome the difficulties of traditional histogram tracking. As well as performing theoretical analysis of the proposed methods, specific example applications are given for both the detection and the tracking aspects, using thermal infrared and visible spectrum video data, as well as other multi-modal information sources
A Survey on Few-Shot Class-Incremental Learning
Large deep learning models are impressive, but they struggle when real-time
data is not available. Few-shot class-incremental learning (FSCIL) poses a
significant challenge for deep neural networks to learn new tasks from just a
few labeled samples without forgetting the previously learned ones. This setup
easily leads to catastrophic forgetting and overfitting problems, severely
affecting model performance. Studying FSCIL helps overcome deep learning model
limitations on data volume and acquisition time, while improving practicality
and adaptability of machine learning models. This paper provides a
comprehensive survey on FSCIL. Unlike previous surveys, we aim to synthesize
few-shot learning and incremental learning, focusing on introducing FSCIL from
two perspectives, while reviewing over 30 theoretical research studies and more
than 20 applied research studies. From the theoretical perspective, we provide
a novel categorization approach that divides the field into five subcategories,
including traditional machine learning methods, meta-learning based methods,
feature and feature space-based methods, replay-based methods, and dynamic
network structure-based methods. We also evaluate the performance of recent
theoretical research on benchmark datasets of FSCIL. From the application
perspective, FSCIL has achieved impressive achievements in various fields of
computer vision such as image classification, object detection, and image
segmentation, as well as in natural language processing and graph. We summarize
the important applications. Finally, we point out potential future research
directions, including applications, problem setups, and theory development.
Overall, this paper offers a comprehensive analysis of the latest advances in
FSCIL from a methodological, performance, and application perspective
Computing Vertex Centrality Measures in Massive Real Networks with a Neural Learning Model
Vertex centrality measures are a multi-purpose analysis tool, commonly used
in many application environments to retrieve information and unveil knowledge
from the graphs and network structural properties. However, the algorithms of
such metrics are expensive in terms of computational resources when running
real-time applications or massive real world networks. Thus, approximation
techniques have been developed and used to compute the measures in such
scenarios. In this paper, we demonstrate and analyze the use of neural network
learning algorithms to tackle such task and compare their performance in terms
of solution quality and computation time with other techniques from the
literature. Our work offers several contributions. We highlight both the pros
and cons of approximating centralities though neural learning. By empirical
means and statistics, we then show that the regression model generated with a
feedforward neural networks trained by the Levenberg-Marquardt algorithm is not
only the best option considering computational resources, but also achieves the
best solution quality for relevant applications and large-scale networks.
Keywords: Vertex Centrality Measures, Neural Networks, Complex Network Models,
Machine Learning, Regression ModelComment: 8 pages, 5 tables, 2 figures, version accepted at IJCNN 2018. arXiv
admin note: text overlap with arXiv:1810.1176
OccFormer: Dual-path Transformer for Vision-based 3D Semantic Occupancy Prediction
The vision-based perception for autonomous driving has undergone a
transformation from the bird-eye-view (BEV) representations to the 3D semantic
occupancy. Compared with the BEV planes, the 3D semantic occupancy further
provides structural information along the vertical direction. This paper
presents OccFormer, a dual-path transformer network to effectively process the
3D volume for semantic occupancy prediction. OccFormer achieves a long-range,
dynamic, and efficient encoding of the camera-generated 3D voxel features. It
is obtained by decomposing the heavy 3D processing into the local and global
transformer pathways along the horizontal plane. For the occupancy decoder, we
adapt the vanilla Mask2Former for 3D semantic occupancy by proposing
preserve-pooling and class-guided sampling, which notably mitigate the sparsity
and class imbalance. Experimental results demonstrate that OccFormer
significantly outperforms existing methods for semantic scene completion on
SemanticKITTI dataset and for LiDAR semantic segmentation on nuScenes dataset.
Code is available at \url{https://github.com/zhangyp15/OccFormer}.Comment: Code is available at https://github.com/zhangyp15/OccForme
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