Goto

Collaborating Authors

 Government


Wagner boss blasts Russia's elite following Moscow drone attack

Al Jazeera

The head of Russia's Wagner mercenary force has again criticised the Russian military and political elite following the drone attack on Moscow that injured two people, damaged property and left some furious the Kremlin had not better protected the capital city. In an expletive-drenched statement posted on Telegram by his press service on Tuesday, Yevgeny Prigozhin โ€“ whose mercenary fighters have played a key role in the war in Ukraine โ€“ blamed the drone attack on out-of-touch officials living in Moscow's affluent suburb of Rublyovka. "You, the Defence Ministry, have done nothing to launch an offensive," Prigozhin said in the statement. "How dare you allow the drones to reach Moscow?" "And what do ordinary people do when drones with explosives crash into their windows?" Focusing his ire on powerful residents of the upmarket Rublyovka area in Moscow's western suburbs, Prigozhin spoke of the "scum" and "swine" who sat quietly while Moscow was attacked.


AI poses 'risk of extinction', tech CEOs warn

Al Jazeera

Taipei, Taiwan โ€“ Artificial intelligence poses a "risk of extinction" that calls for global action, leading computer scientists and technologists have warned. "Mitigating the risk of extinction from AI should be a global priority alongside other societal scale risks such as pandemics and nuclear war," a group of AI experts and other high-profile figures said in a brief statement released by the Center for AI Safety, a San Francisco-based research and advocacy group, on Tuesday. The signatories include technology experts such as Sam Altman, chief executive of OpenAI, Geoffrey Hinton, known as the "godfather of AI", and Audrey Tang, Taiwan's digital minister, as well as other notable figures including the neuroscientist Sam Harris and the musician Grimes. The warning follows an open letter signed by Elon Musk and other high-profile figures in March that called for a six-month pause on the development of AI more advanced than OpenAI's GPT-4. "Powerful AI systems should be developed only once we are confident that their effects will be positive and their risks will be manageable," the letter said.


Prominent AI leaders warn of 'risk of extinction' from new technology

Los Angeles Times

As artificial intelligence races toward everyday adoption, experts have come together -- again -- to express worry over technology's potential power to harm -- or even end -- human life. Months after Elon Musk and numerous others working in the field signed a letter in March seeking a pause in AI development, another group consisting of hundreds of AI-involved business leaders and academics signed on to a new statement from the Center for AI Safety that serves to "voice concerns about some of advanced AI's most severe risks." The new statement, only a sentence long, is meant to "open up discussion" and highlight the rising level of concern among those most versed in the technology,according to the nonprofit's website. The full statement reads: "Mitigating the risk of extinction from AI should be a global priority alongside other societal-scale risks such as pandemics and nuclear war." ChatGPT and other new AI services benefit from a science fiction-infused marketing frenzy unlike anything in recent memory.


Generalizing Neural Wave Functions

arXiv.org Artificial Intelligence

Recent neural network-based wave functions have achieved state-of-the-art accuracies in modeling ab-initio ground-state potential energy surface. However, these networks can only solve different spatial arrangements of the same set of atoms. To overcome this limitation, we present Graph-learned orbital embeddings (Globe), a neural network-based reparametrization method that can adapt neural wave functions to different molecules. Globe learns representations of local electronic structures that generalize across molecules via spatial message passing by connecting molecular orbitals to covalent bonds. Further, we propose a size-consistent wave function Ansatz, the Molecular orbital network (Moon), tailored to jointly solve Schr\"odinger equations of different molecules. In our experiments, we find Moon converging in 4.5 times fewer steps to similar accuracy as previous methods or to lower energies given the same time. Further, our analysis shows that Moon's energy estimate scales additively with increased system sizes, unlike previous work where we observe divergence. In both computational chemistry and machine learning, we are the first to demonstrate that a single wave function can solve the Schr\"odinger equation of molecules with different atoms jointly.


Accuracy on the Curve: On the Nonlinear Correlation of ML Performance Between Data Subpopulations

arXiv.org Artificial Intelligence

Understanding the performance of machine learning (ML) models across diverse data distributions is critically important for reliable applications. Despite recent empirical studies positing a near-perfect linear correlation between in-distribution (ID) and out-of-distribution (OOD) accuracies, we empirically demonstrate that this correlation is more nuanced under subpopulation shifts. Through rigorous experimentation and analysis across a variety of datasets, models, and training epochs, we demonstrate that OOD performance often has a nonlinear correlation with ID performance in subpopulation shifts. Our findings, which contrast previous studies that have posited a linear correlation in model performance during distribution shifts, reveal a "moon shape" correlation (parabolic uptrend curve) between the test performance on the majority subpopulation and the minority subpopulation. This non-trivial nonlinear correlation holds across model architectures, hyperparameters, training durations, and the imbalance between subpopulations. Furthermore, we found that the nonlinearity of this "moon shape" is causally influenced by the degree of spurious correlations in the training data. Our controlled experiments show that stronger spurious correlation in the training data creates more nonlinear performance correlation. We provide complementary experimental and theoretical analyses for this phenomenon, and discuss its implications for ML reliability and fairness. Our work highlights the importance of understanding the nonlinear effects of model improvement on performance in different subpopulations, and has the potential to inform the development of more equitable and responsible machine learning models.


Adapting and Evaluating Influence-Estimation Methods for Gradient-Boosted Decision Trees

arXiv.org Artificial Intelligence

Influence estimation analyzes how changes to the training data can lead to different model predictions; this analysis can help us better understand these predictions, the models making those predictions, and the data sets they're trained on. However, most influence-estimation techniques are designed for deep learning models with continuous parameters. Gradient-boosted decision trees (GBDTs) are a powerful and widely-used class of models; however, these models are black boxes with opaque decision-making processes. In the pursuit of better understanding GBDT predictions and generally improving these models, we adapt recent and popular influence-estimation methods designed for deep learning models to GBDTs. Specifically, we adapt representer-point methods and TracIn, denoting our new methods TREX and BoostIn, respectively; source code is available at https://github.com/jjbrophy47/tree_influence. We compare these methods to LeafInfluence and other baselines using 5 different evaluation measures on 22 real-world data sets with 4 popular GBDT implementations. These experiments give us a comprehensive overview of how different approaches to influence estimation work in GBDT models. We find BoostIn is an efficient influence-estimation method for GBDTs that performs equally well or better than existing work while being four orders of magnitude faster. Our evaluation also suggests the gold-standard approach of leave-one-out (LOO) retraining consistently identifies the single-most influential training example but performs poorly at finding the most influential set of training examples for a given target prediction.


On the Forward Invariance of Neural ODEs

arXiv.org Artificial Intelligence

We propose a new method to ensure neural ordinary differential equations (ODEs) satisfy output specifications by using invariance set propagation. Our approach uses a class of control barrier functions to transform output specifications into constraints on the parameters and inputs of the learning system. This setup allows us to achieve output specification guarantees simply by changing the constrained parameters/inputs both during training and inference. Moreover, we demonstrate that our invariance set propagation through data-controlled neural ODEs not only maintains generalization performance but also creates an additional degree of robustness by enabling causal manipulation of the system's parameters/inputs. We test our method on a series of representation learning tasks, including modeling physical dynamics and convexity portraits, as well as safe collision avoidance for autonomous vehicles.


Domain Adaptive Decision Trees: Implications for Accuracy and Fairness

arXiv.org Artificial Intelligence

In uses of pre-trained machine learning models, it is a known issue that the target population in which the model is being deployed may not have been reflected in the source population with which the model was trained. This can result in a biased model when deployed, leading to a reduction in model performance. One risk is that, as the population changes, certain demographic groups will be under-served or otherwise disadvantaged by the model, even as they become more represented in the target population. The field of domain adaptation proposes techniques for a situation where label data for the target population does not exist, but some information about the target distribution does exist. In this paper we contribute to the domain adaptation literature by introducing domain-adaptive decision trees (DADT). We focus on decision trees given their growing popularity due to their interpretability and performance relative to other more complex models. With DADT we aim to improve the accuracy of models trained in a source domain (or training data) that differs from the target domain (or test data). We propose an in-processing step that adjusts the information gain split criterion with outside information corresponding to the distribution of the target population. We demonstrate DADT on real data and find that it improves accuracy over a standard decision tree when testing in a shifted target population. We also study the change in fairness under demographic parity and equal opportunity. Results show an improvement in fairness with the use of DADT.


Feature Selection on Sentinel-2 Multi-spectral Imagery for Efficient Tree Cover Estimation

arXiv.org Artificial Intelligence

This paper proposes a multi-spectral random forest classifier with suitable feature selection and masking for tree cover estimation in urban areas. The key feature of the proposed classifier is filtering out the built-up region using spectral indices followed by random forest classification on the remaining mask with carefully selected features. Using Sentinel-2 satellite imagery, we evaluate the performance of the proposed technique on a specified area (approximately 82 acres) of Lahore University of Management Sciences (LUMS) and demonstrate that our method outperforms a conventional random forest classifier as well as state-of-the-art methods such as European Space Agency (ESA) WorldCover 10m 2020 product as well as a DeepLabv3 deep learning architecture.


Adversarial-Aware Deep Learning System based on a Secondary Classical Machine Learning Verification Approach

arXiv.org Artificial Intelligence

Deep learning models have been used in creating various effective image classification applications. However, they are vulnerable to adversarial attacks that seek to misguide the models into predicting incorrect classes. Our study of major adversarial attack models shows that they all specifically target and exploit the neural networking structures in their designs. This understanding makes us develop a hypothesis that most classical machine learning models, such as Random Forest (RF), are immune to adversarial attack models because they do not rely on neural network design at all. Our experimental study of classical machine learning models against popular adversarial attacks supports this hypothesis. Based on this hypothesis, we propose a new adversarial-aware deep learning system by using a classical machine learning model as the secondary verification system to complement the primary deep learning model in image classification. Although the secondary classical machine learning model has less accurate output, it is only used for verification purposes, which does not impact the output accuracy of the primary deep learning model, and at the same time, can effectively detect an adversarial attack when a clear mismatch occurs. Our experiments based on CIFAR-100 dataset show that our proposed approach outperforms current state-of-the-art adversarial defense systems.