Oceania
Fine-tune the Entire RAG Architecture (including DPR retriever) for Question-Answering
Siriwardhana, Shamane, Weerasekera, Rivindu, Wen, Elliott, Nanayakkara, Suranga
In September 2020, Facebook open-sourced a new NLP model called Retrieval Augmented Generation (RAG) on the Hugging Face Transformer library. RAG is capable to use a set of support documents from an external knowledge base as a latent variable to generate the final output. The RAG model consists of an Input Encoder, a Neural Retriever, and an Output Generator. All three components are initialized with pre-trained transformers. However, the original Hugging Face implementation only allowed fine-tuning the Input Encoder and the Output Generator in an end-toend manner, while the Neural Retriever needs to be trained seperately. To the best of our knowledge, an end-to-end RAG implementation that trains all three components does not exist.
SeqNetVLAD vs PointNetVLAD: Image Sequence vs 3D Point Clouds for Day-Night Place Recognition
Garg, Sourav, Milford, Michael
Place Recognition is a crucial capability for mobile robot localization and navigation. Image-based or Visual Place Recognition (VPR) is a challenging problem as scene appearance and camera viewpoint can change significantly when places are revisited. Recent VPR methods based on ``sequential representations'' have shown promising results as compared to traditional sequence score aggregation or single image based techniques. In parallel to these endeavors, 3D point clouds based place recognition is also being explored following the advances in deep learning based point cloud processing. However, a key question remains: is an explicit 3D structure based place representation always superior to an implicit ``spatial'' representation based on sequence of RGB images which can inherently learn scene structure. In this extended abstract, we attempt to compare these two types of methods by considering a similar ``metric span'' to represent places. We compare a 3D point cloud based method (PointNetVLAD) with image sequence based methods (SeqNet and others) and showcase that image sequence based techniques approach, and can even surpass, the performance achieved by point cloud based methods for a given metric span. These performance variations can be attributed to differences in data richness of input sensors as well as data accumulation strategies for a mobile robot. While a perfect apple-to-apple comparison may not be feasible for these two different modalities, the presented comparison takes a step in the direction of answering deeper questions regarding spatial representations, relevant to several applications like Autonomous Driving and Augmented/Virtual Reality. Source code available publicly https://github.com/oravus/seqNet.
Curriculum-Driven Multi-Agent Learning and the Role of Implicit Communication in Teamwork
Grupen, Niko A., Lee, Daniel D., Selman, Bart
We propose a curriculum-driven learning strategy for solving difficult multi-agent coordination tasks. Our method is inspired by a study of animal communication, which shows that two straightforward design features (mutual reward and decentralization) support a vast spectrum of communication protocols in nature. We highlight the importance of similarly interpreting emergent communication as a spectrum. We introduce a toroidal, continuous-space pursuit-evasion environment and show that naive decentralized learning does not perform well. We then propose a novel curriculum-driven strategy for multi-agent learning. Experiments with pursuit-evasion show that our approach enables decentralized pursuers to learn to coordinate and capture a superior evader, significantly outperforming sophisticated analytical policies. We argue through additional quantitative analysis -- including influence-based measures such as Instantaneous Coordination -- that emergent implicit communication plays a large role in enabling superior levels of coordination.
Defeasible Reasoning via Datalog$^\neg$
Hardware architectures can range from the use of GPUs and other hardware accelerators, through multi-core multi-threaded architectures, to shared-nothing cloud computing. Causes for failure to exploit these architectures include lack of expertise in the architectural features, lack of manpower more generally, and difficulty in updating legacy systems. Such problems can be ameliorated by mapping a logic to logic programming as an intermediate language. This is a common strategy in the implementation of defeasible logics. The first implementation of a defeasible logic, d-Prolog, was implemented as a Prolog meta-interpreter (Covington et al. 1997). Courteous Logic Programs (Grosof 1997) and its successors LPDA (Wan et al. 2009), Rulelog (Grosof and Kifer 2013), Flora2 (Kifer et al. 2018), are implemented in XSB (Swift and Warren 2012).
Pay Better Attention to Attention: Head Selection in Multilingual and Multi-Domain Sequence Modeling
Gong, Hongyu, Tang, Yun, Pino, Juan, Li, Xian
Multi-head attention has each of the attention heads collect salient information from different parts of an input sequence, making it a powerful mechanism for sequence modeling. Multilingual and multi-domain learning are common scenarios for sequence modeling, where the key challenge is to maximize positive transfer and mitigate negative transfer across languages and domains. In this paper, we find that non-selective attention sharing is sub-optimal for achieving good generalization across all languages and domains. We further propose attention sharing strategies to facilitate parameter sharing and specialization in multilingual and multi-domain sequence modeling. Our approach automatically learns shared and specialized attention heads for different languages and domains to mitigate their interference. Evaluated in various tasks including speech recognition, text-to-text and speech-to-text translation, the proposed attention sharing strategies consistently bring gains to sequence models built upon multi-head attention. For speech-to-text translation, our approach yields an average of $+2.0$ BLEU over $13$ language directions in multilingual setting and $+2.0$ BLEU over $3$ domains in multi-domain setting.
Rep. Mike Gallagher: Truth on COVID, China โ here's why world needs answers about what happened at Wuhan
Fox News correspondent Rich Edson has the latest on China's accountability on'Special Report' At the end of HBO's miniseries "Chernobyl," Soviet nuclear scientist Valery Legosov warns: "Every lie we tell incurs a debt to the truth. Sooner or later that debt is paid." We have spent the last 18 months witnessing China's Chernobyl in the form of the COVID-19 pandemic. Just like the Soviet Union during the Chernobyl nuclear meltdown, from the earliest days of the pandemic when the virus emerged in Wuhan, the Chinese Communist Party (CCP) has engaged in a concerted campaign to pile lies on top of lies about the virus and its origins. Consider that the CCP refused to allow U.S. Centers for Disease Control experts access to Wuhan, and critical data from the Wuhan Institute of Virology (WIV) that could have helped the world get ahead of the disease suddenly disappeared.
Hands-free farming just a robotic arm's length away
Robots and artificial intelligence will replace workers on Australia's first fully automated farm created at a cost of $20 million. Charles Sturt University in Wagga Wagga will create the "hands-free farm" on a 1,900-hectare property to demonstrate what robots and artificial intelligence can do without workers in the paddock. Food Agility chief executive Richard Norton said the reality of "hands-free" farming' was closer than many people realised. "Full automation is not a distant concept. We already have mines in the Pilbara operated entirely through automation", he said "It's not beyond the realms of possibility that a farmer could be sitting in a study in front of a computer driving multiple vehicles".
CAMERAS: Enhanced Resolution And Sanity preserving Class Activation Mapping for image saliency
Jalwana, Mohammad A. A. K., Akhtar, Naveed, Bennamoun, Mohammed, Mian, Ajmal
Backpropagation image saliency aims at explaining model predictions by estimating model-centric importance of individual pixels in the input. However, class-insensitivity of the earlier layers in a network only allows saliency computation with low resolution activation maps of the deeper layers, resulting in compromised image saliency. Remedifying this can lead to sanity failures. We propose CAMERAS, a technique to compute high-fidelity backpropagation saliency maps without requiring any external priors and preserving the map sanity. Our method systematically performs multi-scale accumulation and fusion of the activation maps and backpropagated gradients to compute precise saliency maps. From accurate image saliency to articulation of relative importance of input features for different models, and precise discrimination between model perception of visually similar objects, our high-resolution mapping offers multiple novel insights into the black-box deep visual models, which are presented in the paper. We also demonstrate the utility of our saliency maps in adversarial setup by drastically reducing the norm of attack signals by focusing them on the precise regions identified by our maps. Our method also inspires new evaluation metrics and a sanity check for this developing research direction. Code is available here https://github.com/VisMIL/CAMERAS
Attack to Fool and Explain Deep Networks
Akhtar, Naveed, Jalwana, Muhammad A. A. K., Bennamoun, Mohammed, Mian, Ajmal
Deep visual models are susceptible to adversarial perturbations to inputs. Although these signals are carefully crafted, they still appear noise-like patterns to humans. This observation has led to the argument that deep visual representation is misaligned with human perception. We counter-argue by providing evidence of human-meaningful patterns in adversarial perturbations. We first propose an attack that fools a network to confuse a whole category of objects (source class) with a target label. Our attack also limits the unintended fooling by samples from non-sources classes, thereby circumscribing human-defined semantic notions for network fooling. We show that the proposed attack not only leads to the emergence of regular geometric patterns in the perturbations, but also reveals insightful information about the decision boundaries of deep models. Exploring this phenomenon further, we alter the `adversarial' objective of our attack to use it as a tool to `explain' deep visual representation. We show that by careful channeling and projection of the perturbations computed by our method, we can visualize a model's understanding of human-defined semantic notions. Finally, we exploit the explanability properties of our perturbations to perform image generation, inpainting and interactive image manipulation by attacking adversarialy robust `classifiers'.In all, our major contribution is a novel pragmatic adversarial attack that is subsequently transformed into a tool to interpret the visual models. The article also makes secondary contributions in terms of establishing the utility of our attack beyond the adversarial objective with multiple interesting applications.
TGRNet: A Table Graph Reconstruction Network for Table Structure Recognition
Xue, Wenyuan, Yu, Baosheng, Wang, Wen, Tao, Dacheng, Li, Qingyong
A table arranging data in rows and columns is a very effective data structure, which has been widely used in business and scientific research. Considering large-scale tabular data in online and offline documents, automatic table recognition has attracted increasing attention from the document analysis community. Though human can easily understand the structure of tables, it remains a challenge for machines to understand that, especially due to a variety of different table layouts and styles. Existing methods usually model a table as either the markup sequence or the adjacency matrix between different table cells, failing to address the importance of the logical location of table cells, e.g., a cell is located in the first row and the second column of the table. In this paper, we reformulate the problem of table structure recognition as the table graph reconstruction, and propose an end-to-end trainable table graph reconstruction network (TGRNet) for table structure recognition. Specifically, the proposed method has two main branches, a cell detection branch and a cell logical location branch, to jointly predict the spatial location and the logical location of different cells. Experimental results on three popular table recognition datasets and a new dataset with table graph annotations (TableGraph-350K) demonstrate the effectiveness of the proposed TGRNet for table structure recognition. Code and annotations will be made publicly available.