We study the mixing time of the projected Langevin algorithm (LA) and the privacy curve of noisy Stochastic Gradient Descent (SGD), beyond nonexpansive iterations. Specifically, we derive new mixing time bounds for the projected LA which are, in some important cases, dimension-free and poly-logarithmic on the accuracy, closely matching the existing results in the smooth convex case. Additionally, we establish new upper bounds for the privacy curve of the subsampled noisy SGD algorithm. These bounds show a crucial dependency on the regularity of gradients, and are useful for a wide range of convex losses beyond the smooth case. Our analysis relies on a suitable extension of the Privacy Amplification by Iteration (PABI) framework (Feldman et al., 2018; Altschuler and Talwar, 2022, 2023) to noisy iterations whose gradient map is not necessarily nonexpansive. This extension is achieved by designing an optimization problem which accounts for the best possible R\'enyi divergence bound obtained by an application of PABI, where the tractability of the problem is crucially related to the modulus of continuity of the associated gradient mapping. We show that, in several interesting cases -- including the nonsmooth convex, weakly smooth and (strongly) dissipative -- such optimization problem can be solved exactly and explicitly. This yields the tightest possible PABI-based bounds, where our results are either new or substantially sharper than those in previous works.

Unmodeled aerodynamic disturbances pose a key challenge for multirotor flight when multiple vehicles are in close proximity to each other. However, certain missions \textit{require} two multirotors to approach each other within 1-2 body-lengths of each other and hold formation -- we consider one such practical instance: vertically docking two multirotors in the air. In this leader-follower setting, the follower experiences significant downwash interference from the leader in its final docking stages. To compensate for this, we employ a learnt downwash model online within an optimal feedback controller to accurately track a docking maneuver and then hold formation. Through real-world flights with different maneuvers, we demonstrate that this compensation is crucial for reducing the large vertical separation otherwise required by conventional/naive approaches. Our evaluations show a tracking error of less than 0.06m for the follower (a 3-4x reduction) when approaching vertically within two body-lengths of the leader. Finally, we deploy the complete system to effect a successful physical docking between two airborne multirotors in a single smooth planned trajectory.

Multirotors flying in close proximity induce aerodynamic wake effects on each other through propeller downwash. Conventional methods have fallen short of providing adequate 3D force-based models that can be incorporated into robust control paradigms for deploying dense formations. Thus, learning a model for these downwash patterns presents an attractive solution. In this paper, we present a novel learning-based approach for modelling the downwash forces that exploits the latent geometries (i.e. symmetries) present in the problem. We demonstrate that when trained with only 5 minutes of real-world flight data, our geometry-aware model outperforms state-of-the-art baseline models trained with more than 15 minutes of data. In dense real-world flights with two vehicles, deploying our model online improves 3D trajectory tracking by nearly 36% on average (and vertical tracking by 56%).

More than 60 years since they released their debut single, The Beatles now have their very own academic journal. 'The Journal of Beatles Studies', published by Liverpool University Press, is the first journal to establish The Beatles as an object of scholarly research. Articles in the first issue include'Beatlemania: On informational cascades and spectacular success' and '80 at 80: Commemorating Paul McCartney's eightieth birthday'. The biannual, peer-reviewed journal will publish original, rigorously researched essays and notes, as well as book and media reviews. The journal's first issue has just been published, while the second issue is due sometime in spring 2023 'The Journal of Beatles Studies' is the first journal to establish the band as an object of academic research Editors of the journal are Holly Tessler at the University of Liverpool and Paul Long at Monash University in Melbourne, Australia.

Posted on November 15th, 2022 by Lawrence Tabak, D.D.S., Ph.D. For people who have lost the ability to speak due to a severe disability, they want to get the words out. They just can't physically do it. But in our digital age, there is now a fascinating way to overcome such profound physical limitations. Computers are being taught to decode brain waves as a person tries to speak and then interactively translate them onto a computer screen in real time.

The thin-file borrowers are customers for whom a creditworthiness assessment is uncertain due to their lack of credit history; many researchers have used borrowers' relationships and interactions networks in the form of graphs as an alternative data source to address this. Incorporating network data is traditionally made by hand-crafted feature engineering, and lately, the graph neural network has emerged as an alternative, but it still does not improve over the traditional method's performance. Here we introduce a framework to improve credit scoring models by blending several Graph Representation Learning methods: feature engineering, graph embeddings, and graph neural networks. We stacked their outputs to produce a single score in this approach. We validated this framework using a unique multi-source dataset that characterizes the relationships and credit history for the entire population of a Latin American country, applying it to credit risk models, application, and behavior, targeting both individuals and companies. Our results show that the graph representation learning methods should be used as complements, and these should not be seen as self-sufficient methods as is currently done. In terms of AUC and KS, we enhance the statistical performance, outperforming traditional methods. In Corporate lending, where the gain is much higher, it confirms that evaluating an unbanked company cannot solely consider its features. The business ecosystem where these firms interact with their owners, suppliers, customers, and other companies provides novel knowledge that enables financial institutions to enhance their creditworthiness assessment. Our results let us know when and which group to use graph data and what effects on performance to expect. They also show the enormous value of graph data on the unbanked credit scoring problem, principally to help companies' banking.

Shepard "Shep" Rose recently opened up about courtship through dating apps. The "Southern Charm" star admitted that he used an online dating app to court a model. On Monday, Shep sat with Page Six for an interview where the bachelor revealed that he courted a Victoria's Secret model using Raya, a popular dating app among celebrities. However, he refused to name the celeb he pursued and explained that they never really dated. "No, I didn't go out with her," said Shep. "She ignored me but liked me initially. You both have to like each other [on the app] and then you can start talking."

Janicza Bravo makes short films about loneliness. In one, Michael Cera plays an abrasive paraplegic who can't get lucky. In another, Gaby Hoffmann plays a phone stalker for whom the description "comes on too strong" is not strong enough. Bravo's shorts employ the visual grammar of art-house cinema: over-the-shoulder shots representing a character's point of view, handheld tracking shots depicting urgent movement, lingering closeups to heighten intimacy or unease, carefully composed establishing shots with an actor in the center of the frame. In March, 2015, Bravo went to Venice, on the western edge of Los Angeles, to meet with a production company called Wevr. The name is pronounced "weaver," but it can also be thought of as a sentence, with "We" as the subject and "V.R." as the verb. As anyone who has read a tech blog within the past five years, or a sci-fi novel within the past five decades, knows, "V.R." stands for virtual reality--a loosely defined phrase that is now being applied to several related forms of visual media. You put your smartphone into a portable device like a Google Cardboard or a Samsung Gear--or you use a more powerful computer-based setup, such as the Oculus Rift or the HTC Vive--and the device engulfs your field of vision and tracks your head movement. The filmic world is no longer flat. Wherever you look, there's something to see. The producers at Wevr invited Bravo to write and direct a V.R. project. "I said no," she told me. "It sounded like a technical thing, and I'm not into technical. But then I talked to my husband, and he said, 'How often do people just hand you money in this business?' So I changed my mind." She thought about what kind of story might be told most effectively in the new medium. "The two words I kept hearing about V.R. were'empathy' and'immersion,' and I wasn't sure that being immersed in one of my dark comedies would be all that useful."