Our Beyond-Bayesian-Bandits reading group covered this paper today: Multitasking: Efficient Optimal Planning for Bandit Superprocesses Dylan Hadfield-Menell and Stuart Russell. [Link](https://people.csail.mit.edu/dhm/files/bsp_bbvi.pdf to paper) and its supplementary materials. A bandit superprocess is a decision problem composed from multiple independent Markov decision processes (MDPs), coupled only by the constraint that, at each time step, the agent may act in only one of the MDPs. Multitasking problems of this kind are ubiquitous in the real world, yet very little is known about them from a computational viewpoint, beyond the observation that optimal policies for the superprocess may prescribe actions that would be suboptimal for an MDP considered in isolation....

I was — and still am — a huge Sherlock Holmes fan. I first got into it around age 10, thanks to a Chinese edition I found during a summer holiday at my grandparents’ house. I barely remember the plots now, but the heat, the watermelon, and those long, lazy afternoons spent binging the stories without a single worry in the world were so memorable. There’s something about Holmes that makes him perfect summer reading....

Incoherence is sufficient for exact matrix completion under random sampling. Coherent matrix can also be accurately recovered if random sampling can be contingent on each entry’s local coherence.

Why matrix completion is equivalent to minimizing the recovered matrix’s spectral norm.

Tchaikovsky didn’t like Wagner’s Ring of Nibelungen

(Ariana in Shanghai 2025)

Given a partially observed matrix $ A \in \mathbb{R}^{m \times n} $, where only entries $ A_{ij} $ for $ (i, j) \in \Omega \subseteq [m] \times [n] $ are known, the goal is to recover the missing values and construct a full matrix $ \hat{A} \in \mathbb{R}^{m \times n} $. For example, think of known entries of $A_{ij}$ as observation of $m$ consumers’ past ratings on $n$ products. The goal is to make predictions....

I’m a big fan of Guy Ritchie’s action films. They have rhythm, style, and tension — and above all, they move like music. The Man from U.N.C.L.E. (2015) directed by Guy Ritchie. The Man from U.N.C.L.E. is, at a glance, a classic agent action film — think 007 or Kingsman. It’s sleek, witty, and holds up relatively well in both plot and characters. But what sets it apart is how much care and craftsmanship Ritchie brings to every frame....

Shanghai’s annual Music in the Summer Air (MISA) opens today. This year’s opening concert features Salonen conducting the NY Philharmonic. The program ensembles a luxurious night packed with some of 20th-century’s most color-saturated orchestral music: Ravel’s Ma Mére l’Oye Debussy’s La Mer Berlioz Symphonie Fantastique NY Phil’s musicians has amazing technique (of course) — like in Ma mère l’Oye, the orchestra sounds like it’s breathing in watercolor. Both Ravel and Salonen tonight are really masters of delicate textures....

Professor Nicolas Lambert recently gave a talk at SUFE on ‘Paying for Estimates Incentives in Statistical Reporting.’