Government
Evaluating Model Performance Under Worst-case Subpopulations
Li, Mike, Namkoong, Hongseok, Xia, Shangzhou
The performance of ML models degrades when the training population is different from that seen under operation. Towards assessing distributional robustness, we study the worst-case performance of a model over all subpopulations of a given size, defined with respect to core attributes Z. This notion of robustness can consider arbitrary (continuous) attributes Z, and automatically accounts for complex intersectionality in disadvantaged groups. We develop a scalable yet principled two-stage estimation procedure that can evaluate the robustness of state-of-the-art models. We prove that our procedure enjoys several finite-sample convergence guarantees, including dimension-free convergence. Instead of overly conservative notions based on Rademacher complexities, our evaluation error depends on the dimension of Z only through the out-of-sample error in estimating the performance conditional on Z. On real datasets, we demonstrate that our method certifies the robustness of a model and prevents deployment of unreliable models.
Federated Binary Matrix Factorization using Proximal Optimization
Dalleiger, Sebastian, Vreeken, Jilles, Kamp, Michael
Identifying informative components in binary data is an essential task in many research areas, including life sciences, social sciences, and recommendation systems. Boolean matrix factorization (BMF) is a family of methods that performs this task by efficiently factorizing the data. In real-world settings, the data is often distributed across stakeholders and required to stay private, prohibiting the straightforward application of BMF. To adapt BMF to this context, we approach the problem from a federated-learning perspective, while building on a state-of-the-art continuous binary matrix factorization relaxation to BMF that enables efficient gradient-based optimization. We propose to only share the relaxed component matrices, which are aggregated centrally using a proximal operator that regularizes for binary outcomes. We show the convergence of our federated proximal gradient descent algorithm and provide differential privacy guarantees. Our extensive empirical evaluation demonstrates that our algorithm outperforms, in terms of quality and efficacy, federation schemes of state-of-the-art BMF methods on a diverse set of real-world and synthetic data.
Conditionally valid Probabilistic Conformal Prediction
Plassier, Vincent, Fishkov, Alexander, Panov, Maxim, Moulines, Eric
We develop a new method for creating prediction sets that combines the flexibility of conformal methods with an estimate of the conditional distribution $P_{Y \mid X}$. Most existing methods, such as conformalized quantile regression and probabilistic conformal prediction, only offer marginal coverage guarantees. Our approach extends these methods to achieve conditional coverage, which is essential for many practical applications. While exact conditional guarantees are impossible without assumptions on the data distribution, we provide non-asymptotic bounds that explicitly depend on the quality of the available estimate of the conditional distribution. Our confidence sets are highly adaptive to the local structure of the data, making them particularly useful in high heteroskedasticity situations. We demonstrate the effectiveness of our approach through extensive simulations, showing that it outperforms existing methods in terms of conditional coverage and improves the reliability of statistical inference in a wide range of applications.
S.F. Federal Reserve Bank President Mary Daly Believes AI Can Boost the Labor Market
In an exclusive interview with TIME, San Francisco Federal Reserve president and chief executive Mary Daly said that the explosion of artificial intelligence (AI) could improve the labor market in the long-term and make workers more productive, even as workers fear the rising technology will change or eliminate their jobs. "Jobs are being created, as well as jobs being replaced," Daly said of AI. "If we can get people to upskill or reskill to take the jobs that are being created, we'll have a very successful and growing economy. But that's the burden on us--to make sure that everyone can participate in this changing technological development." TIME sat down with Daly at the Aspen Ideas Festival on June 28 to discuss the nation's monetary policy, a potential softening in the labor market, the role of AI in the workforce, and more. This interview has been condensed and edited for clarity. TIME: Tell me a bit about your role as a Federal Reserve Bank president.
Column: DMV dumps stupid questions for license renewal, but the 'virtual assistant' needs work
A quick look at census data (more than 11,000 people turn 65 each day in the U.S.), along with my own rough calculations, suggest that several hundred people are turning 70 each day in the great state of California, and every 10 minutes or so, one or more of them email me about their license renewal adventures with the DMV. I get the usual, always entertaining horror stories about testing: ("They put in ridiculous questions that do not pertain to driving," said 75-year-old Dahana Klerer of Newport Beach, who flunked twice and added, "I'm not a stupid person but they make you feel really stupid.") California is about to be hit by an aging population wave, and Steve Lopez is riding it. His column focuses on the blessings and burdens of advancing age -- and how some folks are challenging the stigma associated with older adults. "I had no problem," said 79-year-old Ruth Gleason of Ridgecrest, who added: "Thank you and Steve Gordon at the DMV for working to alleviate the test-taking fears for over-70 CA drivers."
'Deepfake' Southgate videos viewed by millions
Earlier this year London Mayor Sadiq Khan said deepfake audio of him supposedly making inflammatory remarks before Armistice Day almost caused "serious disorder". And former Justice Secretary Sir Robert Buckland said AI videos in politics represent a "clear and present danger" to UK democracy. While AI-generated content is allowed on TikTok and Instagram, there are rules on what content is considered harmful. Shortly after the BBC approached TikTok about a number of videos on one account, the material disappeared. It is understood it was taken down because it repeated violations of the platform's AIGC policies.
Diff-BBO: Diffusion-Based Inverse Modeling for Black-Box Optimization
Wu, Dongxia, Kuang, Nikki Lijing, Niu, Ruijia, Ma, Yi-An, Yu, Rose
Black-box optimization (BBO) aims to optimize an objective function by iteratively querying a black-box oracle. This process demands sample-efficient optimization due to the high computational cost of function evaluations. While prior studies focus on forward approaches to learn surrogates for the unknown objective function, they struggle with high-dimensional inputs where valid inputs form a small subspace (e.g., valid protein sequences), which is common in real-world tasks. Recently, diffusion models have demonstrated impressive capability in learning the high-dimensional data manifold. They have shown promising performance in black-box optimization tasks but only in offline settings. In this work, we propose diffusion-based inverse modeling for black-box optimization (Diff-BBO), the first inverse approach leveraging diffusion models for online BBO problem. Diff-BBO distinguishes itself from forward approaches through the design of acquisition function. Instead of proposing candidates in the design space, Diff-BBO employs a novel acquisition function Uncertainty-aware Exploration (UaE) to propose objective function values, which leverages the uncertainty of a conditional diffusion model to generate samples in the design space. Theoretically, we prove that using UaE leads to optimal optimization outcomes. Empirically, we redesign experiments on the Design-Bench benchmark for online settings and show that Diff-BBO achieves state-of-the-art performance.
Self-consistent Deep Geometric Learning for Heterogeneous Multi-source Spatial Point Data Prediction
Yu, Dazhou, Gong, Xiaoyun, Li, Yun, Qiu, Meikang, Zhao, Liang
Multi-source spatial point data prediction is crucial in fields like environmental monitoring and natural resource management, where integrating data from various sensors is the key to achieving a holistic environmental understanding. Existing models in this area often fall short due to their domain-specific nature and lack a strategy for integrating information from various sources in the absence of ground truth labels. Key challenges include evaluating the quality of different data sources and modeling spatial relationships among them effectively. Addressing these issues, we introduce an innovative multi-source spatial point data prediction framework that adeptly aligns information from varied sources without relying on ground truth labels. A unique aspect of our method is the 'fidelity score,' a quantitative measure for evaluating the reliability of each data source. Furthermore, we develop a geo-location-aware graph neural network tailored to accurately depict spatial relationships between data points. Our framework has been rigorously tested on two real-world datasets and one synthetic dataset. The results consistently demonstrate its superior performance over existing state-of-the-art methods.
OxonFair: A Flexible Toolkit for Algorithmic Fairness
Delaney, Eoin, Fu, Zihao, Wachter, Sandra, Mittelstadt, Brent, Russell, Chris
We present OxonFair, a new open source toolkit for enforcing fairness in binary classification. Compared to existing toolkits: (i) We support NLP and Computer Vision classification as well as standard tabular problems. (ii) We support enforcing fairness on validation data, making us robust to a wide range of overfitting challenges. (iii) Our approach can optimize any measure based on True Positives, False Positive, False Negatives, and True Negatives. This makes it easily extendable and much more expressive than existing toolkits. It supports 9/9 and 10/10 of the decision-based group metrics of two popular review papers. (iv) We jointly optimize a performance objective. This not only minimizes degradation while enforcing fairness, but can improve the performance of otherwise inadequately tuned unfair baselines. OxonFair is compatible with standard ML toolkits including sklearn, Autogluon, and PyTorch and is available online at https://github.com/oxfordinternetinstitute/oxonfair
Actionable Cyber Threat Intelligence using Knowledge Graphs and Large Language Models
Fieblinger, Romy, Alam, Md Tanvirul, Rastogi, Nidhi
Cyber threats are constantly evolving. Extracting actionable insights from unstructured Cyber Threat Intelligence (CTI) data is essential to guide cybersecurity decisions. Increasingly, organizations like Microsoft, Trend Micro, and CrowdStrike are using generative AI to facilitate CTI extraction. This paper addresses the challenge of automating the extraction of actionable CTI using advancements in Large Language Models (LLMs) and Knowledge Graphs (KGs). We explore the application of state-of-the-art open-source LLMs, including the Llama 2 series, Mistral 7B Instruct, and Zephyr for extracting meaningful triples from CTI texts. Our methodology evaluates techniques such as prompt engineering, the guidance framework, and fine-tuning to optimize information extraction and structuring. The extracted data is then utilized to construct a KG, offering a structured and queryable representation of threat intelligence. Experimental results demonstrate the effectiveness of our approach in extracting relevant information, with guidance and fine-tuning showing superior performance over prompt engineering. However, while our methods prove effective in small-scale tests, applying LLMs to large-scale data for KG construction and Link Prediction presents ongoing challenges.