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Kevin Chen

Kevin Chen
Real estate is one of the hardest open problems in scaled self driving I’ve had a minor obsession with Waymo’s autonomous vehicle depots recently. Over the past few...
5 months ago
54
5 months ago
I’ve had a minor obsession with Waymo’s autonomous vehicle depots recently. Over the past few months, I’ve flown a drone as part of a stakeout to understand how they work. And I’ve taken a deep dive into an apparent Waymo outage to find the company charging its electric vehicles...
Kevin Chen
Large language models are a sustaining innovation for Siri Many people assume that large language models (LLMs) will disrupt existing consumer voice...
8 months ago
52
8 months ago
Many people assume that large language models (LLMs) will disrupt existing consumer voice assistants. Compared to Siri, while today’s ChatGPT is largely unable to complete real-world tasks like hailing an Uber, it’s far better than Siri at understanding and generating language,...
Kevin Chen
How autonomous vehicle simulation works When autonomous vehicle developers justify the safety of their driverless vehicle deployments, they...
8 months ago
39
8 months ago
When autonomous vehicle developers justify the safety of their driverless vehicle deployments, they lean heavily on their testing in simulation. Common talking points take the form of “we made our car drive X billion miles in simulation.” From these vague statements, it’s...
Kevin Chen
How to create a digital Suica card in Apple Pay (2024 Update) Suica is a smart card used to pay at train stations and convenience stores in Japan. In 2016, Apple...
over a year ago
34
over a year ago
Suica is a smart card used to pay at train stations and convenience stores in Japan. In 2016, Apple added support for Suica to Apple Pay on iPhone 7 devices sold in Japan. In 2017, Apple added support to all iPhone 8/X and later, regardless of where they’re sold.1 Virtual Suica...
Kevin Chen
How Cruise vehicles return to the garage autonomously in heavy rain Cruise doesn’t carry passengers in heavy rain. The operational design domain (ODD) in their CPUC...
over a year ago
20
over a year ago
Cruise doesn’t carry passengers in heavy rain. The operational design domain (ODD) in their CPUC permit (PDF) only allows services in light rain. I’ve always wondered how they implement this operationally. For example, Waymo preemptively launches all cars with operators in the...
Kevin Chen
Tearing down the Rewind app Rewind is a Mac app that records your computer’s screen and audio, allowing the user to scroll...
over a year ago
17
over a year ago
Rewind is a Mac app that records your computer’s screen and audio, allowing the user to scroll through a timeline of past screen recordings. Rewind also recognizes text, including text in videos and Zoom calls, allowing the user to perform full-text search on anything that has...
Kevin Chen
Analyzing Tesla AI Day 2022 I was fortunate enough to attend this year’s Tesla AI Day. Tesla’s architecture has always been...
over a year ago
17
over a year ago
I was fortunate enough to attend this year’s Tesla AI Day. Tesla’s architecture has always been interesting to me because their hardware limitations drive advances in their software. Relative to other players in the industry: Low-spec sensors require ML- and data-first...
Kevin Chen
Saving six round trips with OCSP stapling I was trying to figure out why my site was so slow on my phone after I enabled HTTPS. After all, TLS...
over a year ago
16
over a year ago
I was trying to figure out why my site was so slow on my phone after I enabled HTTPS. After all, TLS is supposed to be fast now, right? But even when there was plenty of bandwidth, it still took several seconds to load a page of text. One WebPageTest later, and I found the...
Kevin Chen
What’s on my ballot: June 2022 California primary election Here’s how I’m voting in the June 2022 primary election. While preparing for this election, I...
over a year ago
15
over a year ago
Here’s how I’m voting in the June 2022 primary election. While preparing for this election, I consulted the San Francisco Chronicle and SPUR endorsements. Contents California Governor Lieutenant Governor Secretary of State Controller Treasurer Insurance Commissioner United...
Kevin Chen
Why autonomous trucking is harder than autonomous rideshare Recently, The Verge asked, “where are all the robot trucks?” It’s a good question. Trucking was...
a year ago
14
a year ago
Recently, The Verge asked, “where are all the robot trucks?” It’s a good question. Trucking was supposed to be the ideal first application of autonomous driving. Freeways contain predictable, highly structured driving scenarios. An autonomous truck would not have to deal with the...
Kevin Chen
What I learned in 2017 At the end of 2017, I wrote down a few important things I’d learned that year. And now that we’re...
over a year ago
14
over a year ago
At the end of 2017, I wrote down a few important things I’d learned that year. And now that we’re more than halfway through 2018, I decided to stop procrastinating and flesh out the details. Some of these things are probably obvious to you, but they were new to me! Being right is...
Kevin Chen
Speeding up code with vectorization I’ve been writing a lot of math code with latency requirements these days. When I talk to people...
over a year ago
14
over a year ago
I’ve been writing a lot of math code with latency requirements these days. When I talk to people about my problems, they usually suggest multithreading and general-purpose GPU computing. These both have downsides. Multithreading might not be the best option in systems that...
Kevin Chen
Ideas for fooling Amazon Go Amazon Go is a grocery store that does away with checkout lines by using computer vision to figure...
over a year ago
14
over a year ago
Amazon Go is a grocery store that does away with checkout lines by using computer vision to figure out what you purchased. What happens if you… Take an item off the shelf and give it to someone else. Go shopping with your identical twin. Use the restroom to put on a face...
Kevin Chen
Why we still can’t stop plagiarism in undergraduate computer science Imagine that you’re hired to work at your local public library. As an eagle-eyed checkout clerk, you...
over a year ago
14
over a year ago
Imagine that you’re hired to work at your local public library. As an eagle-eyed checkout clerk, you soon realize that half the patrons leave without actually checking out their books! This leaves everyone else scratching their heads when the catalog doesn’t match the shelves....
Kevin Chen
!!Con West 2019 Notes !!Con is a conference held every spring in New York City. It’s two days of lightning talks that can...
over a year ago
13
over a year ago
!!Con is a conference held every spring in New York City. It’s two days of lightning talks that can be about anything related to computers! At the beginning of last year’s !!Con, I wrote: This conference is a great showcase of the diverse backgrounds of the NYC tech scene. I’m...
Kevin Chen
What’s on my ballot: November 2022 California general election Here’s how I’m voting in the November 2022 general election. While preparing for this election, I...
over a year ago
13
over a year ago
Here’s how I’m voting in the November 2022 general election. While preparing for this election, I consulted: San Francisco Chronicle voter guide SPUR endorsements GrowSF voter guide, which links to questionnaires from many local candidates that are far more detailed than their...
Kevin Chen
Supporting macOS Mojave’s Dark Mode on the web macOS Mojave adds a Dark Mode for native apps that makes you look approximately 78 percent cooler...
over a year ago
13
over a year ago
macOS Mojave adds a Dark Mode for native apps that makes you look approximately 78 percent cooler when using the computer. In Safari Technology Preview 68, it’s now available on webpages too! Here’s how I added support to this website. Download video Using the...
Kevin Chen
Inferring Cruise occupancy from Kyle Vogt’s fleet dashboard screenshot Background Last month, Kyle Vogt (CEO of Cruise) tweeted a screenshot of Cruise’s fleet management...
over a year ago
13
over a year ago
Background Last month, Kyle Vogt (CEO of Cruise) tweeted a screenshot of Cruise’s fleet management dashboard: The press: AVs are over-hyped and are still 5-10 years away. Us: At this moment there are 100 @Cruise AVs in driverless mode in SF, and many are currently carrying...
Kevin Chen
!!Con 2018 Notes !!Con is a conference held every spring in New York City. It’s two days of lightning talks that can...
over a year ago
12
over a year ago
!!Con is a conference held every spring in New York City. It’s two days of lightning talks that can be about anything related to computers! This conference is a great showcase of the diverse backgrounds of the NYC tech scene. I’m really going to miss it when I move back to the...
Kevin Chen
What’s on my ballot: November 2020 general election Here’s how I’m voting in the November 2020 general election in San Francisco: Contents Federal ...
over a year ago
11
over a year ago
Here’s how I’m voting in the November 2020 general election in San Francisco: Contents Federal President & Vice President US Representative, District 12 California State Legislature State Senator, District 11 State Assembly, District 17 San Francisco City & County ...
Kevin Chen
SIGCSE 2018 notes SIGCSE attendees from Columbia’s Computer Science department. Over the weekend, I attended SIGCSE...
over a year ago
8
over a year ago
SIGCSE attendees from Columbia’s Computer Science department. Over the weekend, I attended SIGCSE — the ACM’s conference on computer science education — with the teaching staff of Columbia’s Advanced Programming course. We learned about everything from rubric design to...