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DynaMo: In-Domain Dynamics Pretraining for Visuo-Motor Control

Neural Information Processing Systems

Imitation learning has proven to be a powerful tool for training complex visuo-motor policies. However, current methods often require hundreds to thousands of expert demonstrations to handle high-dimensional visual observations. A key reason for this poor data efficiency is that visual representations are predominantly either pretrained on out-of-domain data or trained directly through a behavior cloning objective.




Time-Varying Home Field Advantage in Football: Learning from a Non-Stationary Causal Process

Qi, Minhao, Cai, Hengrui, Hu, Guanyu, Shen, Weining

arXiv.org Machine Learning

In sports analytics, home field advantage is a robust phenomenon where the home team wins more games than the away team. However, discovering the causal factors behind home field advantage presents unique challenges due to the non-stationary, time-varying environment of sports matches. In response, we propose a novel causal discovery method, DYnamic Non-stAtionary local M-estimatOrs (DYNAMO), to learn the time-varying causal structures of home field advantage. DYNAMO offers flexibility by integrating various loss functions, making it practical for learning linear and non-linear causal structures from a general class of non-stationary causal processes. By leveraging local information, we provide theoretical guarantees for the identifiability and estimation consistency of non-stationary causal structures without imposing additional assumptions. Simulation studies validate the efficacy of DYNAMO in recovering time-varying causal structures. We apply our method to high-resolution event data from the 2020-2021 and 2021-2022 English Premier League seasons, during which the former season had no audience presence. Our results reveal intriguing, time-varying, team-specific field advantages influenced by referee bias, which differ significantly with and without crowd support. Furthermore, the time-varying causal structures learned by our method improve goal prediction accuracy compared to existing methods.


DynaMo: In-Domain Dynamics Pretraining for Visuo-Motor Control

Neural Information Processing Systems

Imitation learning has proven to be a powerful tool for training complex visuo-motor policies. However, current methods often require hundreds to thousands of expert demonstrations to handle high-dimensional visual observations. A key reason for this poor data efficiency is that visual representations are predominantly either pretrained on out-of-domain data or trained directly through a behavior cloning objective. Given a set of expert demonstrations, we jointly learn a latent inverse dynamics model and a forward dynamics model over a sequence of image embeddings, predicting the next frame in latent space, without augmentations, contrastive sampling, or access to ground truth actions. Importantly, DynaMo does not require any out-of-domain data such as Internet datasets or cross-embodied datasets.


Diversity By Design: Leveraging Distribution Matching for Offline Model-Based Optimization

Yao, Michael S., Gee, James C., Bastani, Osbert

arXiv.org Artificial Intelligence

The goal of offline model-based optimization (MBO) is to propose new designs that maximize a reward function given only an offline dataset. However, an important desiderata is to also propose a diverse set of final candidates that capture many optimal and near-optimal design configurations. We propose Diversity in Adversarial Model-based Optimization (DynAMO) as a novel method to introduce design diversity as an explicit objective into any MBO problem. Our key insight is to formulate diversity as a distribution matching problem where the distribution of generated designs captures the inherent diversity contained within the offline dataset. Extensive experiments spanning multiple scientific domains show that DynAMO can be used with common optimization methods to significantly improve the diversity of proposed designs while still discovering high-quality candidates.


DynaMo: In-Domain Dynamics Pretraining for Visuo-Motor Control

Cui, Zichen Jeff, Pan, Hengkai, Iyer, Aadhithya, Haldar, Siddhant, Pinto, Lerrel

arXiv.org Artificial Intelligence

Imitation learning has proven to be a powerful tool for training complex visuomotor policies. However, current methods often require hundreds to thousands of expert demonstrations to handle high-dimensional visual observations. A key reason for this poor data efficiency is that visual representations are predominantly either pretrained on out-of-domain data or trained directly through a behavior cloning objective. In this work, we present DynaMo, a new in-domain, self-supervised method for learning visual representations. Given a set of expert demonstrations, we jointly learn a latent inverse dynamics model and a forward dynamics model over a sequence of image embeddings, predicting the next frame in latent space, without augmentations, contrastive sampling, or access to ground truth actions. Importantly, DynaMo does not require any out-of-domain data such as Internet datasets or cross-embodied datasets. On a suite of six simulated and real environments, we show that representations learned with DynaMo significantly improve downstream imitation learning performance over prior self-supervised learning objectives, and pretrained representations. Gains from using DynaMo hold across policy classes such as Behavior Transformer, Diffusion Policy, MLP, and nearest neighbors. Finally, we ablate over key components of DynaMo and measure its impact on downstream policy performance. Robot videos are best viewed at https://dynamo-ssl.github.io


Unsupervised Detection of Behavioural Drifts with Dynamic Clustering and Trajectory Analysis

Prenkaj, Bardh, Velardi, Paola

arXiv.org Artificial Intelligence

Real-time monitoring of human behaviours, especially in e-Health applications, has been an active area of research in the past decades. On top of IoT-based sensing environments, anomaly detection algorithms have been proposed for the early detection of abnormalities. Gradual change procedures, commonly referred to as drift anomalies, have received much less attention in the literature because they represent a much more challenging scenario than sudden temporary changes (point anomalies). In this paper, we propose, for the first time, a fully unsupervised real-time drift detection algorithm named DynAmo, which can identify drift periods as they are happening. DynAmo comprises a dynamic clustering component to capture the overall trends of monitored behaviours and a trajectory generation component, which extracts features from the densest cluster centroids. Finally, we apply an ensemble of divergence tests on sliding reference and detection windows to detect drift periods in the behavioural sequence.


Experiments on Generative AI-Powered Parametric Modeling and BIM for Architectural Design

Ko, Jaechang, Ajibefun, John, Yan, Wei

arXiv.org Artificial Intelligence

With the rapid advancement of technology, artificial intelligence (AI) and machine learning (ML) have been integrated into the design process, presenting new opportunities and challenges for architects and designers. However, the potential for AI, particularly language models like ChatGPT - a conversational AI model developed by OpenAI (Radford et al. 2021)- to transform the architectural design process has yet to be fully explored. This paper presents a new framework for architectural design that uses ChatGPT and AI-based ideation and visualization tools, Veras ("VERAS" 2023), to make the design process easier and create 3D geometric models, parametric models, and Building Information Models using natural language input. The proposed framework combines ChatGPT and Veras to generate and explore design ideas rapidly. Using natural language input, architects can communicate their design intentions more intuitively, allowing quicker iterations and reducing barriers associated with traditional design tools (Hsu, Yang, and Buehler 2022). Moreover, ChatGPT's ability to understand human design intentions helps to translate the input into Building Information Modeling (BIM) and parametric Generative AI-Powered Parametric Modeling and BIM for Architectural Design 1 models, highlighting the potential of the architectural design process.


'AI Jesus' talks dating, relationships, morals -- even offers video-gaming tips

FOX News

AI technology is quickly creeping into every industry, prompting new questions about whether online content comes from a human or a computer. A chatbot "version" of Jesus Christ called "Ask_Jesus" is streaming on the gaming platform Twitch -- and it stands ready to answer questions from humans on anything from morality issues to the video game Fortnite to super-powered rodents. Shown with wavy, brown hair and a beatific expression, accompanied by a calm, well-modulated voice, "AI Jesus" calls users on the platform by name -- and appears to consider with care each question asked, as YouTube videos of livestreams reveal. "I am AI Jesus, here to share wisdom based on Jesus' teachings, and help answer questions related to spirituality, personal growth and other wholesome topics," AI Jesus can be heard saying in a video recording of a recent livestream posted to YouTube by Fara Jakari. AI HAS POWER TO'MANIPULATE' AMERICANS, SAYS SEN.