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Get a Grip: Multi-Finger Grasp Evaluation at Scale Enables Robust Sim-to-Real Transfer

arXiv.org Artificial Intelligence

This work explores conditions under which multi-finger grasping algorithms can attain robust sim-to-real transfer. While numerous large datasets facilitate learning generative models for multi-finger grasping at scale, reliable real-world dexterous grasping remains challenging, with most methods degrading when deployed on hardware. An alternate strategy is to use discriminative grasp evaluation models for grasp selection and refinement, conditioned on real-world sensor measurements. This paradigm has produced state-of-the-art results for vision-based parallel-jaw grasping, but remains unproven in the multi-finger setting. In this work, we find that existing datasets and methods have been insufficient for training discriminitive models for multi-finger grasping. To train grasp evaluators at scale, datasets must provide on the order of millions of grasps, including both positive and negative examples, with corresponding visual data resembling measurements at inference time. To that end, we release a new, open-source dataset of 3.5M grasps on 4.3K objects annotated with RGB images, point clouds, and trained NeRFs. Leveraging this dataset, we train vision-based grasp evaluators that outperform both analytic and generative modeling-based baselines on extensive simulated and real-world trials across a diverse range of objects. We show via numerous ablations that the key factor for performance is indeed the evaluator, and that its quality degrades as the dataset shrinks, demonstrating the importance of our new dataset. Project website at: https://sites.google.com/view/get-a-grip-dataset.


Learning a Shape-Conditioned Agent for Purely Tactile In-Hand Manipulation of Various Objects

arXiv.org Artificial Intelligence

Reorienting diverse objects with a multi-fingered hand is a challenging task. Current methods in robotic in-hand manipulation are either object-specific or require permanent supervision of the object state from visual sensors. This is far from human capabilities and from what is needed in real-world applications. In this work, we address this gap by training shape-conditioned agents to reorient diverse objects in hand, relying purely on tactile feedback (via torque and position measurements of the fingers' joints). To achieve this, we propose a learning framework that exploits shape information in a reinforcement learning policy and a learned state estimator. We find that representing 3D shapes by vectors from a fixed set of basis points to the shape's surface, transformed by its predicted 3D pose, is especially helpful for learning dexterous in-hand manipulation. In simulation and real-world experiments, we show the reorientation of many objects with high success rates, on par with state-of-the-art results obtained with specialized single-object agents. Moreover, we show generalization to novel objects, achieving success rates of $\sim$90% even for non-convex shapes.


StockGPT: A GenAI Model for Stock Prediction and Trading

arXiv.org Artificial Intelligence

Generative artificial intelligence (GenAI)--a set of advanced technologies capable of generating texts, images, videos, programming codes, or arts from instructions via sounds or texts--has taken the society by storm and exerted wide-range influences on many aspects of the world economy (Baldassarre et al. 2023; Mannuru et al. 2023; Sรฆtra 2023). Although it had been around for years, GenAI came to public prominence since the introduction of ChatGPT in November 2022, a chatbox able to generate answers, reasoning, and conversations at human level. Since its introduction, ChatGPT and similar large language models have quickly made their ways into the investment industry. One common use of ChatGPT for investment is to give trading recommendations directly from news about a company (such as news articles or corporate communications) (Lopez-Lira and Tang 2023). A less direct approach is to rely on similar pretrained language models such as BERT (Devlin et al. 2018) and OPT (Zhang et al. 2022) to generate a sentiment score for each company which is then used to make trading decisions.


Lyft stock soars thanks to Taylor Swift, Beyoncรฉ and layoffs

The Guardian

Lyft beat estimates for fourth-quarter profit on Tuesday and said it would generate positive free cash flow for the first time in 2024, as the ride-share platform reaps the benefits of heavy cost cuts. Company shares surged nearly 60% in extended trading but erased a third of those gains after the CFO corrected a major mistake in the earnings report. Erin Brewer had said that the company would grow by 500 basis points (5%) in 2024, but later said that the real increase would be a factor of 10 lower โ€“ 50 basis points (0.5%). In 2023, the stock gained about 36%. Rides to stadiums grew more than 35% last year from 2022, mainly driven by Taylor Swift's Eras Tour, Beyoncรฉ's Renaissance World Tour and sporting events, Lyft said.


Assessing Look-Ahead Bias in Stock Return Predictions Generated By GPT Sentiment Analysis

arXiv.org Artificial Intelligence

Large language models (LLMs), including ChatGPT, can extract profitable trading signals from the sentiment in news text. However, backtesting such strategies poses a challenge because LLMs are trained on many years of data, and backtesting produces biased results if the training and backtesting periods overlap. This bias can take two forms: a look-ahead bias, in which the LLM may have specific knowledge of the stock returns that followed a news article, and a distraction effect, in which general knowledge of the companies named interferes with the measurement of a text's sentiment. We investigate these sources of bias through trading strategies driven by the sentiment of financial news headlines. We compare trading performance based on the original headlines with de-biased strategies in which we remove the relevant company's identifiers from the text. In-sample (within the LLM training window), we find, surprisingly, that the anonymized headlines outperform, indicating that the distraction effect has a greater impact than look-ahead bias. This tendency is particularly strong for larger companies--companies about which we expect an LLM to have greater general knowledge. Out-of-sample, look-ahead bias is not a concern but distraction remains possible. Our proposed anonymization procedure is therefore potentially useful in out-of-sample implementation, as well as for de-biased backtesting.


Interpolation of Missing Swaption Volatility Data using Gibbs Sampling on Variational Autoencoders

arXiv.org Machine Learning

In this case, standard stochastic interpolation tools like the common SABR model often cannot be calibrated to observed implied volatility smiles, due to data being only available for the at-the-money quote of the respective underlying swaption. Here, we propose to infer the geometry of the full unknown implied volatility cube by learning stochastic latent representations of implied volatility cubes via variational autoencoders, enabling inference about the missing volatility data conditional on the observed data by an approximate Gibbs sampling approach. Imputed estimates of missing quotes can afterwards be used to fit a standard stochastic volatility model. Since training data for the employed variational autoencoder model is usually sparsely available, we test the robustness of the approach for a model trained on synthetic data on real market quotes and we show that SABR interpolated volatilites calibrated to reconstructed volatility cubes with artificially imputed missing values differ by not much more than two basis points compared to SABR fits calibrated to the complete cube. Moreover, we show how the imputation can be used to successfully set up delta-neutral portfolios for hedging purposes.


Better AI Stock: Nvidia or Palantir

#artificialintelligence

Nvidia (NASDAQ:NVDA) and Palantir (NYSE:PLTR) operate in different sectors, but both tech companies are profiting from the secular expansion of the artificial intelligence (AI) market. Nvidia's GPUs are often associated with video games, but a growing number of data centers are installing its high-end GPUs to process AI tasks. Palantir's data mining platforms accumulate and process data from disparate sources to help government agencies and big companies make AI-driven decisions. Both companies have generated impressive gains over the past 12 months. Nvidia's stock more than doubled as it continued to sell more gaming and data center GPUs. Palantir's stock soared about 160% as it dazzled investors with its robust revenue growth rates and optimistic long-term targets.


Bucketed PCA Neural Networks with Neurons Mirroring Signals

arXiv.org Artificial Intelligence

The bucketed PCA neural network (PCA-NN) with transforms is developed here in an effort to benchmark deep neural networks (DNN's), for problems on supervised classification. Most classical PCA models apply PCA to the entire training data set to establish a reductive representation and then employ non-network tools such as high-order polynomial classifiers. In contrast, the bucketed PCA-NN applies PCA to individual buckets which are constructed in two consecutive phases, as well as retains a genuine architecture of a neural network. This facilitates a fair apple-to-apple comparison to DNN's, esp. to reveal that a major chunk of accuracy achieved by many impressive DNN's could possibly be explained by the bucketed PCA-NN (e.g., 96% out of 98% for the MNIST data set as an example). Compared with most DNN's, the three building blocks of the bucketed PCA-NN are easier to comprehend conceptually - PCA, transforms, and bucketing for error correction. Furthermore, unlike the somewhat quasi-random neurons ubiquitously observed in DNN's, the PCA neurons resemble or mirror the input signals and are more straightforward to decipher as a result.


Pros Holdings: A Buy, Where Artificial Intelligence Benefits From Genuine Intelligence

#artificialintelligence

Readers familiar with our work may want to skip to the Comparing Details heading below. Not because "Technical Analysts" see patterns of past price changes in the stock which may currently fit some part of their folklore and could stir up temporary trading interest. That sector of attention among the investment establishment has, in over 50 years of my observation, consistently failed to provide reliable profitable evidence of the value of studying centuries of stock prices by looking at them in the rear-view mirror. If studying the past can provide some reliable means of dealing with future events, then Artificial Intelligence gets morphed into genuine intelligence thru learning. Our understanding of global and local weather appears to be in this process.


Funds run by artificial intelligence put to test

#artificialintelligence

A computer can trounce a human chess master and solve complex mathematical calculations in seconds. Can it do a better job investing your money than a flesh-and-blood portfolio manager? Investors willing to test that question can do so with a couple of exchange-traded funds, or ETFs, that leave the investment decisions to a computer's so-called artificial intelligence, or AI. ETF Managers Group and Ocean Capital Advisors launched an AI-powered fund last month dubbed the Rogers AI Global Macro ETF that invests primarily in single-country ETFs. The fund's AI sifts through millions of data points from countries around the globe and uses what it learns to determine how best to allocate the fund's holdings.