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CoryOndrejka

2,348 karma · joined January 18, 2009

Co-created Second Life. Saved Facebook. Road Rash 64, lots of other nerd stuff. http://cory.news
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CoryOndrejka··on St Lucie Nuclear Reactor Unit 1 manually shutdown, 3 control rods drop into core
[Correction] as noted below, this type of reactor -- unlike US Navy ones -- can remain critical even with dropped rods. So a better statement here would be that the operators would immediately notice a reduction in criticality. thus power and heat. Then it's a process/policy question about shutdown timing.
CoryOndrejka··on St Lucie Nuclear Reactor Unit 1 manually shutdown, 3 control rods drop into core
Yup, this is me focusing on US Navy reactors, which is my experience. For them, a rod would already take you sub critical.
CoryOndrejka··on St Lucie Nuclear Reactor Unit 1 manually shutdown, 3 control rods drop into core
The dropped rods already shut down the reactor in the sense that it is sub critical. It still has enough leftover heat that it will continue to produce steam for a while, but it would have been almost instantly clear to the operators what had happened.
CoryOndrejka··on St Lucie Nuclear Reactor Unit 1 manually shutdown, 3 control rods drop into core
I don't know this plant. In navy submarine reactors like the S5W, you have 440V/3-phase power holding the clamp. If you dropped a rod due to a power or clamp malfunction, usually you'd simply shut down the reactor, drop all the rods and mechanically re-engage the clamp. It could take a few hours which isn't fun because no power which probably means submarine/snorkel depth to run the incredibly noisy diesel, but no step was particularly hard or dangerous.
CoryOndrejka··on St Lucie Nuclear Reactor Unit 1 manually shutdown, 3 control rods drop into core
and for the curious who didn't what Chernobyl on HBO, other types of reactors have brief criticality increases on rod insertion, which is somewhere between bad, BAD, and OMFGWTFBBQVERYBAD. In the Chernobyl's case, they entered a criticality region known as "prompt criticality" which is where power doubling can happen at prompt neutron rates (e.g. milliseconds or faster). Very very bad. In the case of pressurized water reactors, this isn't what happens. Every moment of control rod descent is reducing criticality.
CoryOndrejka··on St Lucie Nuclear Reactor Unit 1 manually shutdown, 3 control rods drop into core
Exactly what I would have answered :)
CoryOndrejka··on St Lucie Nuclear Reactor Unit 1 manually shutdown, 3 control rods drop into core
Of course, but that's not what happened here. For a pressurized water reactor, there are maintenance and procedural questions about why the rod was dropped. People will likely get fired over this. But from a standpoint of reactor and radiological safety, this is largely the design operating correctly and prioritizing radiological containment.
CoryOndrejka··on St Lucie Nuclear Reactor Unit 1 manually shutdown, 3 control rods drop into core
Dropped rods are an incident but one that occurs because of pressurized water reactors being very default safe. Controls rods are one way the criticality of a reactor is controlled and US reactors (in general) will go sub critical if even one rod is fully inserted into the core. You will likely have heard of a reactor scram (which goes back to the safety control rod ax man) where in an emergency, all the rods are dropped back into the core, greatly reducing its criticality. In some cases, an interruption of electrical power will cause a rod (or three) to drop accidentally. This is a "dropped rod" incident and will force a reactor shut down because it is now sub critical.

Lots of knock on effects -- sub critical, let heat in the primary loop, less steam and electricity generated in the secondary loop, etc -- but generally a non event that you practice for.

There's no reason this would lead to a radiological event or more significant casualty.

CoryOndrejka··on We May Be Living Through the Most Consequential Hundred Days in Cyber History
Combine every attack being a social engineering attack plus foundational model hacking-fu and we're in a shocking interesting place. Identity itself becomes a pretty interesting opportunity/threat. Wrote an oped [1] with friends from Badge on this topic 6 months ago.

[1]: https://idtechwire.com/opinion-in-an-ai-world-every-attack-i...

CoryOndrejka··on 20 years on AWS and never not my job
> in fact in one of Jeff Barr's AWS user meetups in Second Life

There's so much about that phrase that makes me smile. Easy to forget that Second Life was also one of the earliest users of AWS, S3 first. Jeff Bezos had personally invested in our 2005 round (a round that made Linden Lab a unicorn before that was a thing) and pointed us at Jeff Barr and the work coming from AWS.

In return, Jeff Barr started hosting AWS meetups in Second Life -- this was the era of lots of groups setting up Second Life outposts, from Jonathan Coulton to Reuters.

CoryOndrejka··on I Built an Open-World Engine for the N64 [video]
The whole “wheelie to jump cars” but “wheelie require touch on analog stick” is a mechanic I’m shocked other action race games never copied. So much fun to press your luck.
CoryOndrejka··on I Built an Open-World Engine for the N64 [video]
According to a sticky note somehow still stuck to RR64 box, the unlcok everything code is (from the main screen): Control Up, Control Up, Left Trigger, Control Down, Z Trigger, Left Trigger, Z Trigger, Control Up
CoryOndrejka··on I Built an Open-World Engine for the N64 [video]
Yeah, afaik we all faked it in different ways or decided the almost working setting was good enough.
CoryOndrejka··on I Built an Open-World Engine for the N64 [video]
Yeah, so that was what we were in theory "porting." Except that RR3D was streaming off of CD, so they had near infinite disk storage, where we needed to fit in a cartridge. Also -- surprise -- after the contract with EA was signed, it turned out the RR3D team had mostly disbanded inside EA and moved on to other projects, so nobody knew how the streaming worked, where the full map dataset was, how the tracks were represented, etc. Lots of commando visits to EA and long chats later, we had a data dump of the entire map, which was a great start. The compute/storage/graphics performance of the N64 vs PSX were also wildly different, so we ended up having to really rethink virtually all aspects of it.

We also were lucky enough to have an incredible physics engine programmer, so we were running a way better motorcylce simulator than made any kind of sense -- led to huge arguments with our CEO because higher level motorcycles were much harder to ride initially because they were modeled after real performance figures. We fixed that eventually -- Don was right!

Completely agree that none of the games from the CRT era look right on modern TVs. There was a group at GaTech that did some really nice visual simulations of scanline artifacts, but they haven't seemed to generally make it into emulators.

CoryOndrejka··on I Built an Open-World Engine for the N64 [video]
We were subleasing from 3Dfx at the time, working on JetMoto, RR64, and Nuke Strike at the same time. It was old school game development — dumb hours, too much coffee, grabbing tubes of Oreos from the 3Dfx micro kitchen, late night In N’ Out runs for animal style and fries well done. Mix of ex-EA, ex-arcade, and all of us thinking how smart we were to not be leaving games to go to Internet startups. Oops.
CoryOndrejka··on I Built an Open-World Engine for the N64 [video]
Well, in deeply technical terms, it didn’t work at all and just had like one setting that almost worked. The hardware engineers working on the ASIC tried to slam it in at the last minute and they almost pulled it off. Except the didn’t.
CoryOndrejka··on I Built an Open-World Engine for the N64 [video]
The THQ testers figured out you could launch bikes out to the sailboats, too
CoryOndrejka··on I Built an Open-World Engine for the N64 [video]
Thank you! We had an absolute blast building it and we just kept playing it. I need to look up the full unlock cheat code.
CoryOndrejka··on I Built an Open-World Engine for the N64 [video]
Thank you! I’m cracking up because that’s something we all did while building it, too. It’s part of how the insanity bikes ended up so hilariously overpowered.
CoryOndrejka··on I Built an Open-World Engine for the N64 [video]
Very cool. In 1998 (oof) we built Road Rash 64 which was accidentally open world -- even though you had race on a particular road, with a start and finish line, you could drive anywhere, see traffic all over the map, jump off of mountains, etc. The r4k plus reality coprocessor was quite potent -- we got to over 750k shaded triangles per second in optimized testing -- though finicky because you had to manage audio during vblank, etc. Plus, the reality coprocessor fog had a brutal hardware bug that made it really tricky to use.
CoryOndrejka··on Matrix multiplication inches closer to mythic goal
Related to separate paper on using a different method for linear equation solving from a few weeks ago https://www.quantamagazine.org/new-algorithm-breaks-speed-li... seems likely if you can use a different method for solving linear equations, it may be that some matrix multiplication can also be improved using a different method.
CoryOndrejka··on Write your own arbitrary-precision JavaScript math library
Fun article, great style. Couldn’t equality and lte be done more simply with a cross multiply?
CoryOndrejka··on The 3dfx Voodoo1
Oh, memories. We built a custom arcade board based on SLI Voodoo1, mips r5k, and custom jpeg decompression in hardware to do Magic the Gathering: Armageddon. https://youtu.be/cci5l21aMss We wanted to run at highrez (640x480 vga) at 60hz with tons of animating sprites on screen and realized nothing had the fill rate we needed. Rather than changing the game design, we kept looking and met the 3Dfx team when they had barely taped out the Voodoo1. We gambled that SLI would work and started designing the hardware and adapting the game to an early alpha of Glide. We prototyped on SLI cards running on Windows NT and pentium pros. In parallel, Atari Ganes built Voodoo1-based hardware to replace Zoid. Mace and War shipped on that hardware.
CoryOndrejka··on Pelagic Thoroughbreds
Flying Cloud is a wonderful innovation story that connects to the larger story of Matthew Maury, who used US Navy datasets to transform how ships navigated. Gave a talk about this at the US Naval Academy a few years ago, build a bunch of visualizations since NOAA still hosts the data sets http://ondrejka.net/history/2014/02/28/maury.html
CoryOndrejka··on Decades-Old Mystery Put to Rest: Why Are There X's in the Desert?
My dad was project photogrammetrist on Corona when he worked at Itek in the 60s. Lots of stories around focus and aiming challenges, since Corona was used to build maps of inaccessible regions of the world (e.g. Soviet Union ICMB sites). Focus targets gave high contrast, known images to detect what kind of focus problems were being encountered -- ranging from image smear from forward motion compensation failing or stretching the film; film sticking, stretching and/or lifting off of the focal plane; star camera inaccuracies; thermal distortion of camera, spacecraft, star camera, or film; etc. A few good books on Corona (https://www.cia.gov/library/publications/intelligence-histor...) and Itek (https://books.google.com/books/about/Spy_Capitalism.html) out there. Same teams worked on subsequent KH projects (Gambit, Hexagon/Big Bird/BMF), as well as Apollo and Viking camera systems.
CoryOndrejka··on HTML5 Games 0.1: Speedy Sprites (and interesting browser performance analysis)
Running under VMware skewed the first results. We have been hustling to get the code to version 0.1 and I didn't get a comparable test PC in time. We will be rerunning all the benchmarks soon without VMware.

As for using node.js, we're starting to test various communication channels -- websocket versus long poll techniques versus straight ajax etc -- and it's faster for us to be working in a single project as we bootstrap up the tech curve.

CoryOndrejka··on Daring Fireball: Going Flash-Free on Mac OS X, and How to Cheat When You Need It
Doing this in Firefox will result in an annoying "install missing plugins" warning from Firefox. You can click the "x" but to suppress the warning:

* go to about:config

* search on plugin.default_plugin_disabled.

* set to false

CoryOndrejka··on Using genetic algorithms to find Starcraft 2 build orders
This echoes the story of Eurisko, a genetic AI written by Stanford's Douglas Lenat to build Traveller "Trillion Credit Fleets." Eurisko destroyed the competition at the national championship 2 years in row.

http://aliciapatterson.org/APF0704/Johnson/Johnson.html

In both cases, using the GA allowed a player to more comprehensively search the opportunity space created by the game designers than the designers did during design and play testing.

Really awesome stuff, though it sets up an intriguing arm's race between the game designers who can patch and Nerf elements to eliminate unbalanced strategies and the players who then explore the new rule set.

CoryOndrejka··on John Carmack on government
Original comment corrected.
CoryOndrejka··on John Carmack on government
By the way, here is the Wikipedia article for the man in jail for failure to pay taxes: http://en.wikipedia.org/wiki/Walter_Anderson_%28tax_evader%2...

[Edited: had said "friend" which was incorrect]

tl;dr

He admitted to reporting only $67,939 in a year he made $126 million. He further admitted to hiding a total of $365 million.

[Edited: hadn't included the $126 million detail for the year he under-reported]

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