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The Cartesian Cafe

Timothy Nguyen

The Cartesian Cafe is the podcast where an expert guest and Timothy Nguyen map out scientific and mathematical subjects in detail. This collaborative journey with other experts will have us writing down formulas, drawing pictures, and reasoning about them together on a whiteboard. If you’ve been longing for a deeper dive into the intricacies of scientific subjects, then this is the podcast for you. Topics covered include mathematics, physics, computer science, machine learning, and artificial intelligence.

Content also viewable on YouTube: www.youtube.com/timothynguyen and Spotify.

Timothy Nguyen is a mathematician and AI researcher working in industry. Homepage: www.timothynguyen.com, Twitter: @IAmTimNguyen

Patreon: www.patreon.com/timothynguyen

  • 22 episodes
  • Updated Dec 6, 2024

Episodes22

  • Aug 19, 2022 · 1 hr 30 min

    Po-Shen Loh | The Mathematics of COVID-19 Contact Tracing

    Po-Shen Loh is a professor at Carnegie Mellon University and a coach for the US Math Olympiad. He is also a social entrepreneur where he has his used his passion and expertise in mathematics in the service of education (expii.com) and epidemiology (novid.org). In this episode, we discuss the mathematics behind Loh's novel approach to contact tracing in the fight against COVID, which involves a beautiful blend of graph theory and computer science. Originally published on March 3, 2022 on Youtube: https://youtu.be/8CLxLBMGxLE Patreon: https://www.patreon.com/timothynguyen Timestamps: 00:00:00 : Introduction 00:01:11 : About Po-Shen Loh 00:03:49 : NOVID app 00:04:47 : Graph theory and quarantining 00:08:39 : Graph adjacency definition for contact tracing 00:16:01 : Six degrees of separation away from anyone? 00:21:13 : Getting the game theory and incentives right 00:30:40 : Conventional approach to contact tracing 00:34:47 : Comparison with big tech 00:39:19 : Neighbor search complexity 00:45:15 : Watts-Strogatz small networks phenomenon 00:48:37 : Storing neighborhood information 00:57:00 : Random hashing to reduce computational burden 01:05:24 : Logarithmic probing of sparsity 01:09:56 : Two math PhDs struggle to do division 01:11:17 : Bitwise-or for union of bounded sets 01:16:21 : Step back and recap 01:26:15 : Tradeoff between number of hash bins and sparsity 01:29:12 : Conclusion Further reading: Po-Shen Loh. "Flipping the Perspective in Contact Tracing" https://arxiv.org/abs/2010.03806

  • Aug 17, 2022 · 1 min

    Introduction

    Hello everyone, this is Tim Nguyen and welcome to The Cartesian Cafe. On this podcast we embark on a collaborative journey with other experts, to discuss mathematical and scientific topics in faithful detail, which means writing down formulas, drawing pictures, and reasoning about them together on a whiteboard. If you’ve been longing for a deeper dive into the intricacies of scientific subjects, then this is the podcast for you. Welcome to The Cartesian Cafe. Patreon: https://www.patreon.com/timothynguyen