Industry
Coarsening Causal DAG Models
Madaleno, Francisco, Misra, Pratik, Markham, Alex
Directed acyclic graphical (DAG) models are a powerful tool for representing causal relationships among jointly distributed random variables, especially concerning data from across different experimental settings. However, it is not always practical or desirable to estimate a causal model at the granularity of given features in a particular dataset. There is a growing body of research on causal abstraction to address such problems. We contribute to this line of research by (i) providing novel graphical identifiability results for practically-relevant interventional settings, (ii) proposing an efficient, provably consistent algorithm for directly learning abstract causal graphs from interventional data with unknown intervention targets, and (iii) uncovering theoretical insights about the lattice structure of the underlying search space, with connections to the field of causal discovery more generally. As proof of concept, we apply our algorithm on synthetic and real datasets with known ground truths, including measurements from a controlled physical system with interacting light intensity and polarization.
CROCS: A Two-Stage Clustering Framework for Behaviour-Centric Consumer Segmentation with Smart Meter Data
Yerbury, Luke W., Campello, Ricardo J. G. B., Livingston, G. C. Jr, Goldsworthy, Mark, O'Neil, Lachlan
With grid operators confronting rising uncertainty from renewable integration and a broader push toward electrification, Demand-Side Management (DSM) -- particularly Demand Response (DR) -- has attracted significant attention as a cost-effective mechanism for balancing modern electricity systems. Unprecedented volumes of consumption data from a continuing global deployment of smart meters enable consumer segmentation based on real usage behaviours, promising to inform the design of more effective DSM and DR programs. However, existing clustering-based segmentation methods insufficiently reflect the behavioural diversity of consumers, often relying on rigid temporal alignment, and faltering in the presence of anomalies, missing data, or large-scale deployments. To address these challenges, we propose a novel two-stage clustering framework -- Clustered Representations Optimising Consumer Segmentation (CROCS). In the first stage, each consumer's daily load profiles are clustered independently to form a Representative Load Set (RLS), providing a compact summary of their typical diurnal consumption behaviours. In the second stage, consumers are clustered using the Weighted Sum of Minimum Distances (WSMD), a novel set-to-set measure that compares RLSs by accounting for both the prevalence and similarity of those behaviours. Finally, community detection on the WSMD-induced graph reveals higher-order prototypes that embody the shared diurnal behaviours defining consumer groups, enhancing the interpretability of the resulting clusters. Extensive experiments on both synthetic and real Australian smart meter datasets demonstrate that CROCS captures intra-consumer variability, uncovers both synchronous and asynchronous behavioural similarities, and remains robust to anomalies and missing data, while scaling efficiently through natural parallelisation. These results...
Detecting Batch Heterogeneity via Likelihood Clustering
Batch effects represent a major confounder in genomic diagnostics. In copy number variant (CNV) detection from NGS, many algorithms compare read depth between test samples and a reference sample, assuming they are process-matched. When this assumption is violated, with causes ranging from reagent lot changes to multi-site processing, the reference becomes inappropriate, introducing false CNV calls or masking true pathogenic variants. Detecting such heterogeneity before downstream analysis is critical for reliable clinical interpretation. Existing batch effect detection methods either cluster samples based on raw features, risking conflation of biological signal with technical variation, or require known batch labels that are frequently unavailable. We introduce a method that addresses both limitations by clustering samples according to their Bayesian model evidence. The central insight is that evidence quantifies compatibility between data and model assumptions, technical artifacts violate assumptions and reduce evidence, whereas biological variation, including CNV status, is anticipated by the model and yields high evidence. This asymmetry provides a discriminative signal that separates batch effects from biology. We formalize heterogeneity detection as a likelihood ratio test for mixture structure in evidence space, using parametric bootstrap calibration to ensure conservative false positive rates. We validate our approach on synthetic data demonstrating proper Type I error control, three clinical targeted sequencing panels (liquid biopsy, BRCA, and thalassemia) exhibiting distinct batch effect mechanisms, and mouse electrophysiology recordings demonstrating cross-modality generalization. Our method achieves superior clustering accuracy compared to standard correlation-based and dimensionality-reduction approaches while maintaining the conservativeness required for clinical usage.
Random Walk Learning and the Pac-Man Attack
Chen, Xingran, Parag, Parimal, Bhagat, Rohit, Liu, Zonghong, Rouayheb, Salim El
Random walk (RW)-based algorithms have long been popular in distributed systems due to low overheads and scalability, with recent growing applications in decentralized learning. However, their reliance on local interactions makes them inherently vulnerable to malicious behavior. In this work, we investigate an adversarial threat that we term the ``Pac-Man'' attack, in which a malicious node probabilistically terminates any RW that visits it. This stealthy behavior gradually eliminates active RWs from the network, effectively halting the learning process without triggering failure alarms. To counter this threat, we propose the Average Crossing (AC) algorithm--a fully decentralized mechanism for duplicating RWs to prevent RW extinction in the presence of Pac-Man. Our theoretical analysis establishes that (i) the RW population remains almost surely bounded under AC and (ii) RW-based stochastic gradient descent remains convergent under AC, even in the presence of Pac-Man, with a quantifiable deviation from the true optimum. Our extensive empirical results on both synthetic and real-world datasets corroborate our theoretical findings. Furthermore, they uncover a phase transition in the extinction probability as a function of the duplication threshold. We offer theoretical insights by analyzing a simplified variant of the AC, which sheds light on the observed phase transition.
Meta's Layoffs Leave Supernatural Fitness Users in Mourning
Meta's Layoffs Leave Supernatural Fitness Users in Mourning Users of the VR fitness service are distraught that Supernatural has had its staff cut and won't receive any more content updates. I hear a stranger's heavy breathing through the rollicking dude-bro anthem blasting my eardrums, courtesy of the pop-rock band Imagine Dragons. Me and two people I just met are punching digital blocks that fly at our heads in the VR workout platform Supernatural . My new friends have nameplates floating above their heads that say Chip and Alisa. That's all I know about them.
Signal's Founder Built a Chatbot That Can't Spy on You
Signal's Founder Built a Chatbot That Can't Spy on You Welcome back to, TIME's new twice-weekly newsletter about AI. If you're reading this in your browser, why not subscribe to have the next one delivered straight to your inbox? What to Know: Signal's founder is working on encrypted chatbots Moxie Marlinspike, the cryptographic prodigy who wrote the code that underpins Signal and WhatsApp, has a new project--and it could be one of the most important things happening in AI right now. The tool, named Confer, is an end-to-end encrypted AI assistant. It uses smart math to ensure that even though the compute-intensive process of running the AI still happens on a server in the cloud, the only person who can access the unscrambled details of that computation is you, the user.
Take an Extra 50 Off My Favorite Mattress With This Code
Life's Too Short to Put Up With a Bad Mattress--My Favorite Is on Sale Nolah's Evolution is the mattress I personally sleep on as a certified sleep coach, and it's on sale pre-Presidents' Day. I'm a picky person when it comes to mattresses. Of the hundreds I've tested over my career as a certified sleep coach and mattress tester, I have a short list of ones that have exceeded my expectations. At the top of my list is the Nolah Evolution, with the distinct honor of being the mattress I personally own. Given my job, that's got to be like the equivalent of a Grammy or Emmy in the mattress world.
Inside OpenAI's Raid on Thinking Machines Lab
OpenAI is planning to bring over more researchers from Thinking Machines Lab after nabbing two cofounders, a source familiar with the situation says. If someone ever makes an HBO Max series about the AI industry, the events of this week will make quite the episode. On Wednesday, OpenAI's CEO of applications, Fidji Simo, announced the company had rehired Barret Zoph and Luke Metz, cofounders of Mira Murati's AI startup, Thinking Machines Lab. We reported last night on two narratives forming around what led to the departures, and have since learned new information. A source with direct knowledge says that Thinking Machines leadership believed Zoph engaged in an incident of serious misconduct while at the company last year.