Africa
RL-CFR: Improving Action Abstraction for Imperfect Information Extensive-Form Games with Reinforcement Learning
Li, Boning, Fang, Zhixuan, Huang, Longbo
Effective action abstraction is crucial in tackling challenges associated with large action spaces in Imperfect Information Extensive-Form Games (IIEFGs). However, due to the vast state space and computational complexity in IIEFGs, existing methods often rely on fixed abstractions, resulting in sub-optimal performance. In response, we introduce RL-CFR, a novel reinforcement learning (RL) approach for dynamic action abstraction. RL-CFR builds upon our innovative Markov Decision Process (MDP) formulation, with states corresponding to public information and actions represented as feature vectors indicating specific action abstractions. The reward is defined as the expected payoff difference between the selected and default action abstractions. RL-CFR constructs a game tree with RL-guided action abstractions and utilizes counterfactual regret minimization (CFR) for strategy derivation. Impressively, it can be trained from scratch, achieving higher expected payoff without increased CFR solving time. In experiments on Heads-up No-limit Texas Hold'em, RL-CFR outperforms ReBeL's replication and Slumbot, demonstrating significant win-rate margins of $64\pm 11$ and $84\pm 17$ mbb/hand, respectively.
Zero-shot cross-modal transfer of Reinforcement Learning policies through a Global Workspace
Maytiรฉ, Lรฉopold, Devillers, Benjamin, Arnold, Alexandre, VanRullen, Rufin
Humans perceive the world through multiple senses, enabling them to create a comprehensive representation of their surroundings and to generalize information across domains. For instance, when a textual description of a scene is given, humans can mentally visualize it. In fields like robotics and Reinforcement Learning (RL), agents can also access information about the environment through multiple sensors; yet redundancy and complementarity between sensors is difficult to exploit as a source of robustness (e.g. against sensor failure) or generalization (e.g. transfer across domains). Prior research demonstrated that a robust and flexible multimodal representation can be efficiently constructed based on the cognitive science notion of a 'Global Workspace': a unique representation trained to combine information across modalities, and to broadcast its signal back to each modality. Here, we explore whether such a brain-inspired multimodal representation could be advantageous for RL agents. First, we train a 'Global Workspace' to exploit information collected about the environment via two input modalities (a visual input, or an attribute vector representing the state of the agent and/or its environment). Then, we train a RL agent policy using this frozen Global Workspace. In two distinct environments and tasks, our results reveal the model's ability to perform zero-shot cross-modal transfer between input modalities, i.e. to apply to image inputs a policy previously trained on attribute vectors (and vice-versa), without additional training or fine-tuning. Variants and ablations of the full Global Workspace (including a CLIP-like multimodal representation trained via contrastive learning) did not display the same generalization abilities.
A spatiotemporal style transfer algorithm for dynamic visual stimulus generation
Greco, Antonino, Siegel, Markus
Understanding how visual information is encoded in biological and artificial systems often requires vision scientists to generate appropriate stimuli to test specific hypotheses. Although deep neural network models have revolutionized the field of image generation with methods such as image style transfer, available methods for video generation are scarce. Here, we introduce the Spatiotemporal Style Transfer (STST) algorithm, a dynamic visual stimulus generation framework that allows powerful manipulation and synthesis of video stimuli for vision research. It is based on a two-stream deep neural network model that factorizes spatial and temporal features to generate dynamic visual stimuli whose model layer activations are matched to those of input videos. As an example, we show that our algorithm enables the generation of model metamers, dynamic stimuli whose layer activations within our two-stream model are matched to those of natural videos. We show that these generated stimuli match the low-level spatiotemporal features of their natural counterparts but lack their high-level semantic features, making it a powerful paradigm to study object recognition. Late layer activations in deep vision models exhibited a lower similarity between natural and metameric stimuli compared to early layers, confirming the lack of high-level information in the generated stimuli. Finally, we use our generated stimuli to probe the representational capabilities of predictive coding deep networks. These results showcase potential applications of our algorithm as a versatile tool for dynamic stimulus generation in vision science.
Fundamental limits of Non-Linear Low-Rank Matrix Estimation
Mergny, Pierre, Ko, Justin, Krzakala, Florent, Zdeborovรก, Lenka
We consider the task of estimating a low-rank matrix from non-linear and noisy observations. We prove a strong universality result showing that Bayes-optimal performances are characterized by an equivalent Gaussian model with an effective prior, whose parameters are entirely determined by an expansion of the non-linear function. In particular, we show that to reconstruct the signal accurately, one requires a signal-to-noise ratio growing as $N^{\frac 12 (1-1/k_F)}$, where $k_F$ is the first non-zero Fisher information coefficient of the function. We provide asymptotic characterization for the minimal achievable mean squared error (MMSE) and an approximate message-passing algorithm that reaches the MMSE under conditions analogous to the linear version of the problem. We also provide asymptotic errors achieved by methods such as principal component analysis combined with Bayesian denoising, and compare them with Bayes-optimal MMSE.
USS Carney shoots down drones, missile fired by Houthis in Yemen
U.S. destroyer USS Carney shot down drones and a missile fired toward it in the Red Sea by Yemen's Houthi rebels, U.S. Central Command (CENTCOM) announced Wednesday. USS Carney, an Arleigh Burke-class destroyer that has been involved in the American campaign against the Iranian-backed rebels, shot down one anti-ship ballistic missile and three one-way attack unmanned aerial systems launched from Houthi-controlled areas of Yemen between 3 p.m. and 5 p.m. Sanaa time, CENTCOM said. Several hours later, CENTCOM forces destroyed three anti-ship missiles and three unmanned surface vessels (USV) in self-defense. The missiles and USVs were located in Houthi-controlled areas of Yemen. "CENTCOM forces identified the missiles, UAVs, and USVs and determined that they presented an imminent threat to merchant vessels and to the U.S. Navy ships in the region," CENTCOM said in a statement.
What's Going On with Kara Swisher's Book Tour?
Last week saw the release of Kara Swisher's Burn Book, the highly anticipated career memoir from a titanic, justly celebrated veteran of tech journalism. Considering her unique, outsize stature in Silicon Valley, and her decadeslong record of landing bombshell inside scoops about the single most important industry of the 21st century, Swisher's choice to promote her latest project with the help of famous friends (Don Lemon, Massachusetts Gov. Maura Healey, etc.) certainly makes sense. What makes much less sense, however, is her selection of tech-world executives. The book tour is going to be lit -- with guest moderators like @RobertIger, @laurenepowell, @mcuban, @donlemon, @reidhoffman, @sama and more. Some of the "moderators" on her tour include Laurene Powell Jobs, Disney CEO Bob Iger, OpenAI CEO Sam Altman, LinkedIn co-founder Reid Hoffman, and Lean In board member Adam Grant. Per NPR's Steve Inskeep, she personally requested that these folks "interview her on stage," in a series of conversations she intends to turn into individual podcast episodes.
RADIA -- Radio Advertisement Detection with Intelligent Analytics
รlvarez, Jorge, Armenteros, Juan Carlos, Torrรณn, Camilo, Ortega-Martรญn, Miguel, Ardoiz, Alfonso, Garcรญa, รscar, Arranz, Ignacio, Galdeano, รรฑigo, Garrido, Ignacio, Alonso, Adriรกn, Bayรณn, Fernando, Vorontsov, Oleg
Radio advertising remains an integral part of modern marketing strategies, with its appeal and potential for targeted reach undeniably effective. However, the dynamic nature of radio airtime and the rising trend of multiple radio spots necessitates an efficient system for monitoring advertisement broadcasts. This study investigates a novel automated radio advertisement detection technique incorporating advanced speech recognition and text classification algorithms. RadIA's approach surpasses traditional methods by eliminating the need for prior knowledge of the broadcast content. This contribution allows for detecting impromptu and newly introduced advertisements, providing a comprehensive solution for advertisement detection in radio broadcasting. Experimental results show that the resulting model, trained on carefully segmented and tagged text data, achieves an F1-macro score of 87.76 against a theoretical maximum of 89.33. This paper provides insights into the choice of hyperparameters and their impact on the model's performance. This study demonstrates its potential to ensure compliance with advertising broadcast contracts and offer competitive surveillance. This groundbreaking research could fundamentally change how radio advertising is monitored and open new doors for marketing optimization.
Media Bias Matters: Understanding the Impact of Politically Biased News on Vaccine Attitudes in Social Media
Jiang, Bohan, Cheng, Lu, Tan, Zhen, Guo, Ruocheng, Liu, Huan
News media has been utilized as a political tool to stray from facts, presenting biased claims without evidence. Amid the COVID-19 pandemic, politically biased news (PBN) has significantly undermined public trust in vaccines, despite strong medical evidence supporting their efficacy. In this paper, we analyze: (i) how inherent vaccine stances subtly influence individuals' selection of news sources and participation in social media discussions; and (ii) the impact of exposure to PBN on users' attitudes toward vaccines. In doing so, we first curate a comprehensive dataset that connects PBN with related social media discourse. Utilizing advanced deep learning and causal inference techniques, we reveal distinct user behaviors between social media groups with various vaccine stances. Moreover, we observe that individuals with moderate stances, particularly the vaccine-hesitant majority, are more vulnerable to the influence of PBN compared to those with extreme views. Our findings provide critical insights to foster this line of research.
Neural Additive Image Model: Interpretation through Interpolation
Reuter, Arik, Thielmann, Anton, Saefken, Benjamin
Understanding how images influence the world, interpreting which effects their semantics have on various quantities and exploring the reasons behind changes in image-based predictions are highly difficult yet extremely interesting problems. By adopting a holistic modeling approach utilizing Neural Additive Models in combination with Diffusion Autoencoders, we can effectively identify the latent hidden semantics of image effects and achieve full intelligibility of additional tabular effects. Our approach offers a high degree of flexibility, empowering us to comprehensively explore the impact of various image characteristics. We demonstrate that the proposed method can precisely identify complex image effects in an ablation study. To further showcase the practical applicability of our proposed model, we conduct a case study in which we investigate how the distinctive features and attributes captured within host images exert influence on the pricing of Airbnb rentals.
Enhancing Price Prediction in Cryptocurrency Using Transformer Neural Network and Technical Indicators
Khaniki, Mohammad Ali Labbaf, Manthouri, Mohammad
Abstract: This study presents an innovative approach for predicting cryptocurrency time series, specifically focusing on Bitcoin, Ethereum, and Litecoin. The methodology integrates the use of technical indicators, a Performer neural network, and BiLSTM (Bidirectional Long Short-Term Memory) to capture temporal dynamics and extract significant features from raw cryptocurrency data. The Performer neural network, employing Fast Attention Via positive Orthogonal Random features (FAVOR+), has demonstrated superior computational efficiency and scalability compared to the traditional Multi-head attention mechanism in Transformer models. Additionally, the integration of BiLSTM in the feedforward network enhances the model's capacity to capture temporal dynamics in the data, processing it in both forward and backward directions. This is particularly advantageous for time series data where past and future data points can influence the current state. The proposed method has been applied to the hourly and daily timeframes of the major cryptocurrencies and its performance has been benchmarked against other methods documented in the literature. The results underscore the potential of the proposed method to outperform existing models, marking a significant progression in the field of cryptocurrency price prediction. Keywords: Cryptocurrency, Deep Learning, Time Series prediction, Transformer, Performer, Attention Mechanism, 1) Introduction In the rapidly evolving landscape of technology, the mode of transactions has undergone a significant paradigm shift. Traditional physical payments, such as cash and cheques, are increasingly being replaced by digital transactions. This transformation has been largely driven by the advent and proliferation of cryptocurrencies, which have emerged as a new asset class and medium of exchange (Aghashahi and Bamdad, 2023).