Since finally being rid of my PhD work, I’ve been hitting a bunch of projects that have been on my TODO list for ages.
The oldest so far is this PSU which has been sitting for …decades… in my parts pile with some compatible machines, and I’ve always intended to try rebuilding it. It died with a “ticking” symptom some time in the mid-00s.
I finally got around to it this week, and it wasn’t a bad job. About $10 of parts, a few hours of work, and it’s back in action. Rebuild details below.
It took another round of “longer than expected” because, while I passed my defense at the end of July, I had some requests to make significant changes to the dissertation before submitting my final copy, and that didn’t get wrapped up until early September with my advisor paying meaningful attention to what I was doing for the first time in years.
I ended up having to include a lot of the modern academic hype-spewing, stake-claiming bullshit I’ve developed a deep distaste for, but even with that I’ll admit it’s a much better document overall after the rewrite. It looks less negative than the earlier drafts, because they were largely written before my last “I give up, I’ll try one more stupid thing” experiment finally turned up something reasonably compelling.
The copy of record of the dissertation is published, here are local PDF copies of the deck from my defense and my dissertation. More information below.
Then I had several weeks of catch-up for all the many things in my life I’ve been shorting time to get done, while I was having the apparently requisite back-and-forth with the graduate school about petty formatting matters, but it is done.
Continue readingThe largest reason I’ve been starving every one of my other interests, like posting here, for the last several years is finally wrapping up, and looks like it will get me a PhD in Computer Science.
Wednesday July 24, 2024. 1:00PM. 101 Davis Marksbury Building.
Title: Post-Capture Synthesis of Images Using Manipulable Integration Functions
Abstract:
Traditional photographic practice, as dictated by the properties of photochemical emulsion film, mechanical apparatus, and human operators, largely treats the sensitivity (gain) and integration interval as coarsely parameterized constants for the entire scene, set no later than the time of exposure. This frame-at-a-time capture and processing model permeates digital cameras and computer image processing.
Emerging imaging technologies, such as time domain continuous imaging (TDCI), quanta image sensors (QIS), event cameras, and conventional sensors augmented with computational processing and control, provide opportunities to break out of the frame-oriented paradigm and capture a stream of data describing changes to scene appearance over the capture interval with high temporal precision. Captured scene data can then be computationally post-processed to render images with user control over the time interval being sampled and the gain of integration, not just for each image rendered but for every site in each rendered image, allowing the user to ideally expose each portion of the scene. For example, in a scene that contains a mixture of moving elements some of which are more brightly lit, it becomes possible to render dark and light portions with different gains and potentially overlapping intervals, such that both have good contrast, neither one suffers motion blur, and little to no artifacting occurs at the interfaces.
This thesis represents a preliminary exploration of the properties, application, and tooling required to capture TDCI streams and render images from them in a paradigm that supports functional post-capture manipulation of time and gain.
So excited to be rid of this thing. It’s a genuinely nifty idea, and sort-of the idea I started out with, but I’m very tired of looking at it.
If any internet friends want to come watch me talk shit about it for ~1 hour, you’re welcome.
I’ll post my thesis and slides after it’s done.
Firefox has a facility to use native file pickers via xdg-portals, which most of the internet will tell you is set in a key in about:config called widget.use-xdg-desktop-portal. Quite some time ago, that was split into more granular keys so … Continue reading
There have been some intermittent issues with this site for the last few days because some shitheel has been hammering the server that hosts web-facing things for me with automated script-kiddy bullshit that my existing hardening didn’t automatically catch.
Roughly 10GB of it in the last week.
With user agents set to around 500,000 different Chrome versions.
I noticed because the (small) box has been OOM killing processes any time the stats tools look at the logs of this behavior.
Most of it came from one address (in the AliCloud IP allocation, as always. I’ll continue to half-pretend it’s just a compromised VM) so I cleaned up the worst of it by adding an nftables rule to drop anything from that saddr, and did a little filtering to the logs to fix the OOM situation.
I’ve also turned on some rate-limiting features in nginx, and rigged fail2ban to block repeated violators of the rate limit, so hopefully things are more permanently taken care of.
I was having Vulkan/Wine interaction issues when I had a minute to play a game the other night and flipped my big laptop (which has Intel/AMD Polaris12 dual graphics, both running the Mesa stack since AMD dropped Polaris support in amdvlk in the 2023.Q4 release) into a Plasma Wayland session (v5.27) to see if it helped. It did – making it the very first thing I’ve encountered that worked in Wayland and not X – so I’m rolling with the Plasma Wayland session for a couple days to see how things are. I have a little machine I’ve been playing with Hyprland on to check out the Wayland situation, and it’s been closing from “Linux 20 years ago” to “Linux 5 years ago” in terms of brokenness, so it seems plausible that one of the big two would be tolerable now.
I’m totally onboard that xf86->xorg is an unmaintainable mess for both legacy-codebase and design from a different era reasons, and it would be nice to start with something built on assumptions that match modern reality, but uh… over a decade in, Wayland is just getting to be less of a “almost a tech demo” and more of an “almost there.” If the devs can shut up about some bikeshedding that obstructs common use cases now over concerns about theoretical security issues or compatibility with yet-unimagined future interface models and implement widely-accepted solutions to the last few basic-fucking-features, it might actually matter before it too starts to exhibit wrong ancient assumptions and gets replaced, but it looks like they’ve missed the bus on a couple of those necessary standardizations.
Things I use regularly that are currently broken in KDE’s Plasma Wayland session in Nov. 2023:
The whole situation is silly. It’s a gigantic shell-game of trying to outsource the solutions to problems everyone already knew needed to be solved consistently because the ICCM and EWMH stuff for X represented decades of effort to do so, by the people best situated to actually solve the problems at the time when they could be solved in a general way.
I sometimes get the feeling reading the bug trackers that many of the Wayland people are building a display layer suitable for infotainment systems, kiosks, signage, and that sort of thing, and desktop functionality is an unfortunate extra thing some people are trying to force on them – which, financially, may be the case.
Look at this time crystal on shopgoodwill. A pristine Antec SX1030 case (or chieftech dragon or one of the other clones), painted metallic green with a window installed. Every commercial or DIY gaming PC in the first few years of … Continue reading
I got talked into going to SC again this year, as I have almost every year since 2009.
It’s not really my area of focus, but it’s always interesting.
UK’s presence featured a mixture of IT/CCS types and researchers, the research end of the booth was mostly focused on ongoing Parallel Bit Pattern Computing work, featuring a new demo/visualization thing that I built much of the hardware and some of the software for in the 3 weeks before we left for the conference (the rest came from Hank modelling some printable parts, pulling the compute engine from an older demo he wrote, and building some adapter code). It was more exhausting than the conference itself, but a really fun prototyping/micomanufacturing flex. Fancy 3D printed parts, 2020 extrusion, some laser cut bits, piles of addressable LEDs, a bit of embedded electronics. There is also a partially-functional prototype backplane to link 4 EBAZ425 FPGA boards through an Aggregate Function Network as a PBP substrate that …I designed. There’s a lot of not-my-job work I did on display; I should probably start throwing more of a fit about that.
Some notes about the stuff we were showing and interesting(?) industry observations below.
Continue readingI had nothing to do with this but I’m super excited. There has been a long-standing bug in the CPU emulation in Basilisk II (a 68K Macintosh emulator) that could be reliably triggered when *inhales* Bruno the shark killed you … Continue reading
Several years ago I picked up a used Dell Chromebook 11 3189 (model code “Kefka”) to play with. At the time it was still receiving ChromeOS updates, had a sticky hinge that required some lubrication and manipulation to get working, and cost around $100 including the separately purchased power adapter. I’ve hacked on it in a wide variety of ways over the years, and the main interesting result is that I’m starting to think a hacked out-of-support x86 Chromebook is, in many ways, now better and cheaper than a Raspberry Pi in that role as a modern accessible extra computer to enable fearless play the Pi was intended to fill. I’ve been taking notes, so way too much detail below.
Continue reading
