pwc-archive/papers-with-abstracts huggingface dataset:
A Deep-Learning Usability Expansion Model of Ocean Observations
Authors: Ali Muhamed Ali, Hanqi Zhuang, Yu Huang, Ali K. Ibrahim, Ali Salem Altaher, Laurent Chérubin
Date: 2022-06-03 00:00:00
Tasks: Deep Learning, Image Segmentation, Semantic Segmentation

Today's ocean numerical prediction skills depend on the availability of in-situ and remote ocean observations at the time of the predictions only. Because observations are scarce and discontinuous in time and space, numerical models are often unable to accurately model and predict real ocean dynamics, leading to a lack of fulfillment of a range of services that require reliable predictions at various temporal and spatial scales. The process of constraining free numerical models with observations is known as data assimilation. The primary objective is to minimize the misfit of model states with the observations while respecting the rules of physics. The caveat of this approach is that measurements are used only once, at the time of the prediction. The information contained in the history of the measurements and its role in the determinism of the prediction is, therefore, not accounted for. Consequently, historical measurement cannot be used in real-time forecasting systems. The research presented in this paper provides a novel approach rooted in artificial intelligence to expand the usability of observations made before the time of the prediction. Our approach is based on the re-purpose of an existing deep learning model, called U-Net, designed specifically for image segmentation analysis in the biomedical field. U-Net is used here to create a Transform Model that retains the temporal and spatial evolution of the differences between model and observations to produce a correction in the form of regression weights that evolves spatially and temporally with the model both forward and backward in time, beyond the observation period. Using virtual observations, we show that the usability of the observation can be extended up to a one year prior or post observations.
Vision-Aided Frame-Capture-Based CSI Recomposition for WiFi Sensing: A Multimodal Approach
Authors: Hiroki Shimomura, Yusuke Koda, Takamochi Kanda, Koji Yamamoto, Takayuki Nishio, Akihito Taya
Date: 2022-06-03 00:00:00
Tasks: Multimodal Deep Learning

Recompositing channel state information (CSI) from the beamforming feedback matrix (BFM), which is a compressed version of CSI and can be captured because of its lack of encryption, is an alternative way of implementing firmware-agnostic WiFi sensing. In this study, we propose the use of camera images toward the accuracy enhancement of CSI recomposition from BFM. The key motivation for this vision-aided CSI recomposition is to draw a first-hand insight that the BFM does not fully involve spatial information to recomposite CSI and that this could be compensated by camera images. To leverage the camera images, we use multimodal deep learning, where the two modalities, i.e., images and BFMs, are integrated to recomposite the CSI. We conducted experiments using IEEE 802.11ac devices. The experimental results confirmed that the recomposition accuracy of the proposed multimodal framework is improved compared to the single-modal framework only using images or BFMs.
LAPIS is a fast web API for massive open virus sequencing databases
Authors: Chaoran Chen, Alexander Taepper, Fabian Engelniederhammer, Jonas Kellerer, Cornelius Roemer, Tanja Stadler
Date: 2022-06-02 00:00:00
Tasks: Epidemiology, Retrieval

Background: Recent epidemic outbreaks such as the SARS-CoV-2 pandemic and the mpox outbreak in 2022 have demonstrated the value of genomic sequencing data for tracking the origin and spread of pathogens. Laboratories around the globe generated new sequences at unprecedented speed and volume and bioinformaticians developed new tools and dashboards to analyze this wealth of data. However, a major challenge that remains is the lack of simple and efficient approaches for accessing and processing sequencing data. Results: The Lightweight API for Sequences (LAPIS) facilitates rapid retrieval and analysis of genomic sequencing data through a REST API. It supports complex mutation- and metadata-based queries and can perform aggregation operations on massive datasets. LAPIS is optimized for typical questions relevant to genomic epidemiology. Using a newly-developed in-memory database engine, it has a high speed and throughput: between 25 January and 4 February 2023, the SARS-CoV-2 instance of LAPIS, which contains 14.5 million sequences, processed over 20 million requests with a mean response time of 411 ms and a median response time of 1 ms. LAPIS is the core engine behind our dashboards on genspectrum.org and we currently maintain public LAPIS instances for SARS-CoV-2 and mpox. Conclusions: Powered by an optimized database engine and available through a web API, LAPIS enhances the accessibility of genomic sequencing data. It is designed to serve as a common backend for dashboards and analyses with the potential to be integrated into common database platforms such as GenBank.
Entropy and the arrow of time in population dynamics
Authors: Diogo Costa-Cabanas, Fabio A. C. C. Chalub, Max O. Souza
Date: 2022-06-03 00:00:00

The concept of entropy in statistical physics is related to the existence of irreversible macroscopic processes. In this work, we explore a recently introduced entropy formula for a class of stochastic processes with more than one absorbing state that is extensively used in population genetics models. We will consider the Moran process as a paradigm for this class, and will extend our discussion to other models outside this class. We will also discuss the relation between non-extensive entropies in physics and epistasis (i.e., when the effects of different alleles are not independent) and the role of symmetries in population genetic models.
PCL: Proxy-Based Contrastive Learning for Domain Generalization
Authors: Xufeng Yao, Yang Bai, Xinyun Zhang, Yuechen Zhang, Qi Sun, Ran Chen, Ruiyu Li, Bei Yu
Date: 2022-01-01 00:00:00
Proceeding: CVPR 2022 1
Tasks: Contrastive Learning, Domain Generalization

    Domain generalization refers to the problem of training a model from a collection of different source domains that can directly generalize to the unseen target domains. A promising solution is contrastive learning, which attempts to learn domain-invariant representations by exploiting rich semantic relations among sample-to-sample pairs from different domains. A simple approach is to pull positive sample pairs from different domains closer while pushing other negative pairs further apart. In this paper, we find that directly applying contrastive-based methods (e.g., supervised contrastive learning) are not effective in domain generalization. We argue that aligning positive sample-to-sample pairs tends to hinder the model generalization due to the significant distribution gaps between different domains. To address this issue, we propose a novel proxy-based contrastive learning method, which replaces the original sample-to-sample relations with proxy-to-sample relations, significantly alleviating the positive alignment issue. Experiments on the four standard benchmarks demonstrate the effectiveness of the proposed method. Furthermore, we also consider a more complex scenario where no ImageNet pre-trained models are provided. Our method consistently shows better performance.
GeoEngine: A Platform for Production-Ready Geospatial Research
Authors: Sagar Verma, Siddharth Gupta, Hal Shin, Akash Panigrahi, Shubham Goswami, Shweta Pardeshi, Natanael Exe, Ujwal Dutta, Tanka Raj Joshi, Nitin Bhojwani
Date: 2022-01-01 00:00:00
Proceeding: CVPR 2022 1
Tasks: BIG-bench Machine Learning

    Geospatial machine learning has seen tremendous academic advancement, but its practical application has been constrained by difficulties with operationalizing performant and reliable solutions. Sourcing satellite imagery in real-world settings, handling terabytes of training data, and managing machine learning artifacts are a few of the challenges that have severely limited downstream innovation. In this paper we introduce the GeoEngine platform for reproducible and production-ready geospatial machine learning research. GeoEngine removes key technical hurdles to adopting computer vision and deep learning-based geospatial solutions at scale. It is the first end-to-end geospatial machine learning platform, simplifying access to insights locked behind petabytes of imagery. Backed by a rigorous research methodology, this geospatial framework empowers researchers with powerful abstractions for image sourcing, dataset development, model development, large scale training, and model deployment. In this paper we provide the GeoEngine architecture explaining our design rationale in detail. We provide several real-world use cases of image sourcing, dataset development, and model building that have helped different organisations build and deploy geospatial solutions.
C-CAM: Causal CAM for Weakly Supervised Semantic Segmentation on Medical Image
Authors: Zhang Chen, Zhiqiang Tian, Jihua Zhu, Ce Li, Shaoyi Du
Date: 2022-01-01 00:00:00
Proceeding: CVPR 2022 1
Tasks: Anatomy, Organ Segmentation, Segmentation, Semantic Segmentation, Weakly supervised Semantic Segmentation, Weakly-Supervised Semantic Segmentation

    Recently, many excellent weakly supervised semantic segmentation (WSSS) works are proposed based on class activation mapping (CAM). However, there are few works that consider the characteristics of medical images. In this paper, we find that there are mainly two challenges of medical images in WSSS: i) the boundary of object foreground and background is not clear; ii) the co-occurrence phenomenon is very severe in training stage. We thus propose a Causal CAM (C-CAM) method to overcome the above challenges. Our method is motivated by two cause-effect chains including category-causality chain and anatomy-causality chain. The category-causality chain represents the image content (cause) affects the category (effect). The anatomy-causality chain represents the anatomical structure (cause) affects the organ segmentation (effect). Extensive experiments were conducted on three public medical image data sets. Our C-CAM generates the best pseudo masks with the DSC of 77.26%, 80.34% and 78.15% on ProMRI, ACDC and CHAOS compared with other CAM-like methods. The pseudo masks of C-CAM are further used to improve the segmentation performance for organ segmentation tasks. Our C-CAM achieves DSC of 83.83% on ProMRI and DSC of 87.54% on ACDC, which outperforms state-of-the-art WSSS methods. Our code is available at https://github.com/Tian-lab/C-CAM.
BTS: A Bi-Lingual Benchmark for Text Segmentation in the Wild
Authors: Xixi Xu, Zhongang Qi, jianqi ma, Honglun Zhang, Ying Shan, XiaoHu Qie
Date: 2022-01-01 00:00:00
Proceeding: CVPR 2022 1
Tasks: Segmentation, Style Transfer, Text Segmentation, Text Style Transfer

    As a prerequisite of many text-related tasks such as text erasing and text style transfer, text segmentation arouses more and more attention recently. Current researches mainly focus on only English characters and digits, while few work studies Chinese characters due to the lack of public large-scale and high-quality Chinese datasets, which limits the practical application scenarios of text segmentation. Different from English which has a limited alphabet of letters, Chinese has much more basic characters with complex structures, making the problem more difficult to deal with. To better analyze this problem, we propose the Bi-lingual Text Segmentation (BTS) dataset, a benchmark that covers various common Chinese scenes including 14,250 diverse and fine-annotated text images. BTS mainly focuses on Chinese characters, and also contains English words and digits. We also introduce Prior Guided Text Segmentation Network (PGTSNet), the first baseline to handle bi-lingual and complex-structured text segmentation. A plug-in text region highlighting module and a text perceptual discriminator are proposed in PGTSNet to supervise the model with text prior, and guide for more stable and finer text segmentation. A variation loss is also employed for suppressing background noise under complex scene. Extensive experiments are conducted not only to demonstrate the necessity and superiority of the proposed dataset BTS, but also to show the effectiveness of the proposed PGTSNet compared with a variety of state-of-the-art text segmentation methods.
Data-Free Network Compression via Parametric Non-Uniform Mixed Precision Quantization
Authors: Vladimir Chikin, Mikhail Antiukh
Date: 2022-01-01 00:00:00
Proceeding: CVPR 2022 1
Tasks: Quantization

    Deep Neural Networks (DNNs) usually have a large number of parameters and consume a huge volume of storage space, which limits the application of DNNs on memory-constrained devices. Network quantization is an appealing way to compress DNNs. However, most of existing quantization methods require the training dataset and a fine-tuning procedure to preserve the quality of a full-precision model. These are unavailable for the confidential scenarios due to personal privacy and security problems. Focusing on this issue, we propose a novel data-free method for network compression called PNMQ, which employs the Parametric Non-uniform Mixed precision Quantization to generate a quantized network. During the compression stage, the optimal parametric non-uniform quantization grid is calculated directly for each layer to minimize the quantization error. User can directly specify the required compression ratio of a network, which is used by the PNMQ algorithm to select bitwidths of layers. This method does not require any model retraining or expensive calculations, which allows efficient implementations for network compression on edge devices. Extensive experiments have been conducted on various computer vision tasks and the results demonstrate that PNMQ achieves better performance than other state-of-the-art methods of network compression.
En-Compactness: Self-Distillation Embedding & Contrastive Generation for Generalized Zero-Shot Learning
Authors: Xia Kong, Zuodong Gao, Xiaofan Li, Ming Hong, Jun Liu, Chengjie Wang, Yuan Xie, Yanyun Qu
Date: 2022-01-01 00:00:00
Proceeding: CVPR 2022 1
Tasks: Generalized Zero-Shot Learning, Zero-Shot Learning

    Generalized zero-shot learning (GZSL) requires a classifier trained on seen classes that can recognize objects from both seen and unseen classes. Due to the absence of unseen training samples, the classifier tends to bias towards seen classes. To mitigate this problem, feature generation based models are proposed to synthesize visual features for unseen classes. However, these features are generated in the visual feature space which lacks of discriminative ability. Therefore, some methods turn to find a better embedding space for the classifier training. They emphasize the inter-class relationships of seen classes, leading the embedding space overfitted to seen classes and unfriendly to unseen classes. Instead, in this paper, we propose an Intra-Class Compactness Enhancement method (ICCE) for GZSL. Our ICCE promotes intra-class compactness with inter-class separability on both seen and unseen classes in the embedding space and visual feature space. By promoting the intra-class relationships but the inter-class structures, we can distinguish different classes with better generalization. Specifically, we propose a Self-Distillation Embedding (SDE) module and a Semantic-Visual Contrastive Generation (SVCG) module. The former promotes intra-class compactness in the embedding space, while the latter accomplishes it in the visual feature space. The experiments demonstrate that our ICCE outperforms the state-of-the-art methods on four datasets and achieves competitive results on the remaining dataset.
LTP: Lane-Based Trajectory Prediction for Autonomous Driving
Authors: Jingke Wang, Tengju Ye, Ziqing Gu, Junbo Chen
Date: 2022-01-01 00:00:00
Proceeding: CVPR 2022 1
Tasks: Autonomous Driving, Diversity, Graph Neural Network, Motion Forecasting, Prediction, Trajectory Prediction

    The reasonable trajectory prediction of surrounding traffic participants is crucial for autonomous driving. Especially, how to predict multiple plausible trajectories is still a challenging problem because of the multiple possibilities of the future. Proposal-based prediction methods address the multi-modality issues with a two-stage approach, commonly using intention classification followed by motion regression. This paper proposes a two-stage proposal-based motion forecasting method that exploits the sliced lane segments as fine-grained, shareable, and interpretable proposals. We use Graph neural network and Transformer to encode the shape and interaction information among the map sub-graphs and the agents sub-graphs. In addition, we propose a variance-based non-maximum suppression strategy to select representative trajectories that ensure the diversity of the final output. Experiments on the Argoverse dataset show that the proposed method outperforms state-of-the-art methods, and the lane segments-based proposals as well as the variance-based non-maximum suppression strategy both contribute to the performance improvement. Moreover, we demonstrate that the proposed method can achieve reliable performance with a lower collision rate and fewer off-road scenarios in the closed-loop simulation.
Text-to-Image Synthesis Based on Object-Guided Joint-Decoding Transformer
Authors: Fuxiang Wu, Liu Liu, Fusheng Hao, Fengxiang He, Jun Cheng
Date: 2022-01-01 00:00:00
Proceeding: CVPR 2022 1
Tasks: Image Generation, Object, Task 2

    Object-guided text-to-image synthesis aims to generate images from natural language descriptions built by two-step frameworks, i.e., the model generates the layout and then synthesizes images from the layout and captions. However, such frameworks have two issues: 1) complex structure, since generating language-related layout is not a trivial task; 2) error propagation, because the inappropriate layout will mislead the image synthesis and is hard to be revised. In this paper, we propose an object-guided joint-decoding module to simultaneously generate the image and the corresponding layout. Specially, we present the joint-decoding transformer to model the joint probability on images tokens and the corresponding layouts tokens, where layout tokens provide additional observed data to model the complex scene better. Then, we describe a novel Layout-VQGAN for layout encoding and decoding to provide more information about the complex scene. After that, we present the detail-enhanced module to enrich the language-related details based on two facts: 1) visual details could be omitted in the compression of VQGANs; 2) the joint-decoding transformer would not have sufficient generating capacity. The experiments show that our approach is competitive with previous object-centered models and can generate diverse and high-quality objects under the given layouts.
Better Trigger Inversion Optimization in Backdoor Scanning
Authors: Guanhong Tao, Guangyu Shen, Yingqi Liu, Shengwei An, QiuLing Xu, Shiqing Ma, Pan Li, Xiangyu Zhang
Date: 2022-01-01 00:00:00
Proceeding: CVPR 2022 1

    Backdoor attacks aim to cause misclassification of a subject model by stamping a trigger to inputs. Backdoors could be injected through malicious training and naturally exist. Deriving backdoor trigger for a subject model is critical to both attack and defense. A popular trigger inversion method is by optimization. Existing methods are based on finding a smallest trigger that can uniformly flip a set of input samples by minimizing a mask. The mask defines the set of pixels that ought to be perturbed. We develop a new optimization method that directly minimizes individual pixel changes, without using a mask. Our experiments show that compared to existing methods, the new one can generate triggers that require a smaller number of input pixels to be perturbed, have a higher attack success rate, and are more robust. They are hence more desirable when used in real-world attacks and more effective when used in defense. Our method is also more cost-effective.
Lagrange Motion Analysis and View Embeddings for Improved Gait Recognition
Authors: Tianrui Chai, Annan Li, Shaoxiong Zhang, Zilong Li, Yunhong Wang
Date: 2022-01-01 00:00:00
Proceeding: CVPR 2022 1
Tasks: Gait Recognition

    Gait is considered the walking pattern of human body, which includes both shape and motion cues. However, the main-stream appearance-based methods for gait recognition rely on the shape of silhouette. It is unclear whether motion can be explicitly represented in the gait sequence modeling. In this paper, we analyzed human walking using the Lagrange's equation and come to the conclusion that second-order information in the temporal dimension is necessary for identification. We designed a second-order motion extraction module based on the conclusions drawn. Also, a light weight view-embedding module is designed by analyzing the problem that current methods to cross-view task do not take view itself into consideration explicitly. Experiments on CASIA-B and OU-MVLP datasets show the effectiveness of our method and some visualization for extracted motion are done to show the interpretability of our motion extraction module.
Robust Federated Learning With Noisy and Heterogeneous Clients
Authors: Xiuwen Fang, Mang Ye
Date: 2022-01-01 00:00:00
Proceeding: CVPR 2022 1
Tasks: Federated Learning

    Model heterogeneous federated learning is a challenging task since each client independently designs its own model. Due to the annotation difficulty and free-riding participant issue, the local client usually contains unavoidable and varying noises, which cannot be effectively addressed by existing algorithms. This paper starts the first attempt to study a new and challenging robust federated learning problem with noisy and heterogeneous clients. We present a novel solution RHFL (Robust Heterogeneous Federated Learning), which simultaneously handles the label noise and performs federated learning in a single framework. It is featured in three aspects: (1) For the communication between heterogeneous models, we directly align the models feedback by utilizing public data, which does not require additional shared global models for collaboration. (2) For internal label noise, we apply a robust noise-tolerant loss function to reduce the negative effects. (3) For challenging noisy feedback from other participants, we design a novel client confidence re-weighting scheme, which adaptively assigns corresponding weights to each client in the collaborative learning stage. Extensive experiments validate the effectiveness of our approach in reducing the negative effects of different noise rates/types under both model homogeneous and heterogeneous federated learning settings, consistently outperforming existing methods.