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VL-BEiT: Generative Vision-Language Pretraining

arXiv.org Artificial Intelligence

We introduce a vision-language foundation model called VL-BEiT, which is a bidirectional multimodal Transformer learned by generative pretraining. Our minimalist solution conducts masked prediction on both monomodal and multimodal data with a shared Transformer. Specifically, we perform masked vision-language modeling on image-text pairs, masked language modeling on texts, and masked image modeling on images. VL-BEiT is learned from scratch with one unified pretraining task, one shared backbone, and one-stage training. Our method is conceptually simple and empirically effective. Experimental results show that VL-BEiT obtains strong results on various vision-language benchmarks, such as visual question answering, visual reasoning, and image-text retrieval. Moreover, our method learns transferable visual features, achieving competitive performance on image classification, and semantic segmentation.


Symplectically Integrated Symbolic Regression of Hamiltonian Dynamical Systems

arXiv.org Artificial Intelligence

Here we present Symplectically Integrated Symbolic Regression (SISR), a novel technique for learning physical governing equations from data. SISR employs a deep symbolic regression approach, using a multi-layer LSTM-RNN with mutation to probabilistically sample Hamiltonian symbolic expressions. Using symplectic neural networks, we develop a model-agnostic approach for extracting meaningful physical priors from the data that can be imposed on-the-fly into the RNN output, limiting its search space. Hamiltonians generated by the RNN are optimized and assessed using a fourth-order symplectic integration scheme; prediction performance is used to train the LSTM-RNN to generate increasingly better functions via a risk-seeking policy gradients approach. Employing these techniques, we extract correct governing equations from oscillator, pendulum, two-body, and three-body gravitational systems with noisy and extremely small datasets.


Mind the Gap! Injecting Commonsense Knowledge for Abstractive Dialogue Summarization

arXiv.org Artificial Intelligence

In this paper, we propose to leverage the unique characteristics of dialogues sharing commonsense knowledge across participants, to resolve the difficulties in summarizing them. We present SICK, a framework that uses commonsense inferences as additional context. Compared to previous work that solely relies on the input dialogue, SICK uses an external knowledge model to generate a rich set of commonsense inferences and selects the most probable one with a similarity-based selection method. Built upon SICK, SICK++ utilizes commonsense as supervision, where the task of generating commonsense inferences is added upon summarizing the dialogue in a multi-task learning setting. Experimental results show that with injected commonsense knowledge, our framework generates more informative and consistent summaries than existing methods.


Remember and Forget Experience Replay for Multi-Agent Reinforcement Learning

arXiv.org Artificial Intelligence

We present the extension of the Remember and Forget for Experience Replay (ReF-ER) algorithm to Multi-Agent Reinforcement Learning (MARL). ReF-ER was shown to outperform state of the art algorithms for continuous control in problems ranging from the OpenAI Gym to complex fluid flows. In MARL, the dependencies between the agents are included in the state-value estimator and the environment dynamics are modeled via the importance weights used by ReF-ER. In collaborative environments, we find the best performance when the value is estimated using individual rewards and we ignore the effects of other actions on the transition map. We benchmark the performance of ReF-ER MARL on the Stanford Intelligent Systems Laboratory (SISL) environments. We find that employing a single feed-forward neural network for the policy and the value function in ReF-ER MARL, outperforms state of the art algorithms that rely on complex neural network architectures.


Dialogue Evaluation with Offline Reinforcement Learning

arXiv.org Artificial Intelligence

Task-oriented dialogue systems aim to fulfill user goals through natural language interactions. They are ideally evaluated with human users, which however is unattainable to do at every iteration of the development phase. Simulated users could be an alternative, however their development is nontrivial. Therefore, researchers resort to offline metrics on existing human-human corpora, which are more practical and easily reproducible. They are unfortunately limited in reflecting real performance of dialogue systems. BLEU for instance is poorly correlated with human judgment, and existing corpus-based metrics such as success rate overlook dialogue context mismatches. There is still a need for a reliable metric for task-oriented systems with good generalization and strong correlation with human judgements. In this paper, we propose the use of offline reinforcement learning for dialogue evaluation based on a static corpus. Such an evaluator is typically called a critic and utilized for policy optimization. We go one step further and show that offline RL critics can be trained on a static corpus for any dialogue system as external evaluators, allowing dialogue performance comparisons across various types of systems. This approach has the benefit of being corpus- and model-independent, while attaining strong correlation with human judgements, which we confirm via an interactive user trial.


Are Attribute Inference Attacks Just Imputation?

arXiv.org Artificial Intelligence

Models can expose sensitive information about their training data. In an attribute inference attack, an adversary has partial knowledge of some training records and access to a model trained on those records, and infers the unknown values of a sensitive feature of those records. We study a fine-grained variant of attribute inference we call \emph{sensitive value inference}, where the adversary's goal is to identify with high confidence some records from a candidate set where the unknown attribute has a particular sensitive value. We explicitly compare attribute inference with data imputation that captures the training distribution statistics, under various assumptions about the training data available to the adversary. Our main conclusions are: (1) previous attribute inference methods do not reveal more about the training data from the model than can be inferred by an adversary without access to the trained model, but with the same knowledge of the underlying distribution as needed to train the attribute inference attack; (2) black-box attribute inference attacks rarely learn anything that cannot be learned without the model; but (3) white-box attacks, which we introduce and evaluate in the paper, can reliably identify some records with the sensitive value attribute that would not be predicted without having access to the model. Furthermore, we show that proposed defenses such as differentially private training and removing vulnerable records from training do not mitigate this privacy risk. The code for our experiments is available at \url{https://github.com/bargavj/EvaluatingDPML}.


Artificial intelligence has created a kit for every World Cup team - and some are stunning

#artificialintelligence

The 2022 World Cup is only a few months away and we're positively overcome with excitement. With the latest tournament's unprecedented move to the winter, football fans have been left to wait longer than ever for the premier competition in the men's game and anticipation is quickly rising towards fever pitch. And although there is plenty of club action to enjoy before the global football carnival kicks off on November 21, supporters have been given a tantalising glimpse at what they can expect from Qatar 2022 this week. Well, at least from an aesthetic perspective, that is, because Puma and Adidas have helped to whip up excitement by dropping the first bunch of brand new kits that will be on display at the tournament. From controversial'box' templates to gorgeous designs for Japan, Mexico and Germany, there are now plenty of World Cup jerseys that have either been released or leaked for the world to see.


Microsoft's Activision Blizzard deal faces more UK scrutiny

Associated Press

Microsoft's plan to buy video game company Activision Blizzard faced a potential setback Thursday after British antitrust regulators demanded concessions from both companies to ease competition concerns about the blockbuster deal. The Competition and Markets Authority said it was worried the $69 billion deal would hurt rivals by restricting their access to Activision Blizzard games. It also worried that the combined company would stifle competition in the emerging cloud gaming market. The authority gave both companies five days to come up with proposals to address its concerns, otherwise it would escalate its investigation with more scrutiny. The all-cash deal is set to be the largest in the history of the tech industry.


Mixing tokens with Fourier transforms to improve the efficiency of large language models

AIHub

James Lee-Thorp, Joshua Ainslie, Ilya Eckstein and Santiago Ontañón won the best efficient NLP paper award at NAACL 2022 for their paper FNet: Mixing Tokens with Fourier Transforms. Here, the authors tell us about how they are working to improve the efficiency of large language models. In our paper, we study faster transformer models. Transformers have proven remarkably successful at modeling everything from language to protein structures. We replace the computationally expensive self-attention layers in transformer encoders with faster, linear transformations.


Traversability analysis with vision and terrain probing for safe legged robot navigation

arXiv.org Artificial Intelligence

Inspired by human behavior when traveling over unknown terrain, this study proposes the use of probing strategies and integrates them into a traversability analysis framework to address safe navigation on unknown rough terrain. Our framework integrates collapsibility information into our existing traversability analysis, as vision and geometric information alone could be misled by unpredictable non-rigid terrains such as soft soil, bush area, or water puddles. With the new traversability analysis framework, our robot has a more comprehensive assessment of unpredictable terrain, which is critical for its safety in outdoor environments. The pipeline first identifies the terrain's geometric and semantic properties using an RGB-D camera and desired probing locations on questionable terrains. These regions are probed using a force sensor to determine the risk of terrain collapsing when the robot steps over it. This risk is formulated as a collapsibility metric, which estimates an unpredictable region's ground collapsibility. Thereafter, the collapsibility metric, together with geometric and semantic spatial data, is combined and analyzed to produce global and local traversability grid maps. These traversability grid maps tell the robot whether it is safe to step over different regions of the map. The grid maps are then utilized to generate optimal paths for the robot to safely navigate to its goal. Our approach has been successfully verified on a quadrupedal robot in both simulation and real-world experiments.