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fraserphysics

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Show HN: Markov Models and Dynamical Systems – Software and Book

gitlab.com
4 ポイント·投稿者 fraserphysics·8 か月前·0 コメント

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fraserphysics
·27 日前·議論
The second law of thermodynamics implies that one must spend energy as work to move thermal energy up a temperature difference. So the net effect of an air conditioner is to increase the total amount of thermal energy.
fraserphysics
·先月·議論
For a long time I've been reading that the closure of Hormuz is going to constrain consumption soon. I understand the economic theory that reducing supply of an inelastic commodity greatly increases the price. The article says that inventories have insulated us from high prices so far. I am surprised by how large and effective those inventories have been. And I am surprised that futures prices are not higher. Can anyone here suggest explanations?
fraserphysics
·先月·議論
It was so long ago that I've forgotten most of it. I was impressed that it was based on evidence based literature. Here is a link to the training now https://carpentries.org/instructor-training/ I am disappointed that I don't see a reading list.

Unless it's changed since I was active, The Carpentries does not monetize content.
fraserphysics
·先月·議論
I signed up for software carpentry instructor training at the SciPy conference in 2015. I expected to learn about their curriculum. Instead, I found that they taught pedagogy. There were articles to read in advance. I should have taken that class before I spent 15 years teaching at university rather than afterwards.
fraserphysics
·先月·議論
When I worked at Los Alamos, the head of counterintelligence was a former CIA ops guy. He seemed warm and intelligent; just an all around good guy. In presentations, he explained that his job at the CIA was to exploit that appearance to ruin people's lives. He said his approach was to gain the trust of a mark, and then provide him with what ever was required to get him to betray things he loved. The presentations were effective, enlightening and spooky.

So, I agree: All spies are bastards.
fraserphysics
·2 か月前·議論
This article was in Springer's The Mathematical Intelligencer in 1980. The next article in that volume was "Strange Attractors" by David Ruelle. When I read Ruelle's article in the early 1980s, I noticed Knuth's article. By the time I got to writing my third paper on strange attractors in 1988, I was using TeX.
fraserphysics
·3 か月前·議論
Helium will leak out of some structures that hold methane. Shale will trap methane and let helium escape. Layers of salt trap both. Thus horizontal drilling and fracking to recover oil and methane from shale produces very little helium.
fraserphysics
·3 か月前·議論
Tracy Kidder's father and grandfather (Henry M. and Henry M. Jr.) were partners in the law firm that's now Seward and Kissel. My great grandfather was a partner in the firm when he died in 1935. I've heard that everyone liked and admired my great grandfather. The Kidders took care of his descendants for the next say 65 years. In 1977 when I got a Bachelors degree in Physics, HMK Jr. wrote a will for me. We met at the Seward and Kissel office to get it signed and notarized, and HMK Jr. took me to lunch at a fancy club downtown. After some martinis, he told me that there'd been two generations of losers in my family, and that everyone thought with my degree in Physics, I could pick up the mantle.

Then he said that he wished his son, Tracy, had an interest in real science like me. When I asked what Tracy was doing, Henry described a silly project of hanging out with computer engineers.

I enjoyed "The Soul of a New Machine" when it came out. I always hoped that I could meet Tracy someday. I guess not. He did great work, I hope his father learned to be proud.
fraserphysics
·5 か月前·議論
Thank you for articulately describing an ugly part of the world of science that I've seen over the last 40 years. I appreciate your "There but for the grace of God" thought. If I were a bigger star, I can only hope that I would have behaved better than some of those big stars.
fraserphysics
·5 か月前·議論
After free UNIX and Linux became available on affordable home computers, I found it was no longer necessary to be at a company to do interesting projects. That was before 1995.
fraserphysics
·6 か月前·議論
Encouraged by the replies here, I tried to get quickemu to setup macOS on my AMD based desktop. The emulated machine crashed trying to boot macOS, and I gave up after a couple of hours.
fraserphysics
·6 か月前·議論
I thought that macOS was proprietary, and that apple only allowed it to be run on apple hardware. Just last month, I used incus to test a software package in 6 Linux distributions. I want to also test the package in macOS. Must I get a license from apple to do that with Quickemu?
fraserphysics
·7 か月前·議論
I'm polishing up the second edition of "Hidden Markov Models and Dynamical Systems." The book explains several state space models and connects them to ideas about chaos. Here's a link to a pdf draft: https://www.fraserphysics.com/book.pdf and here's a link to source for the book: https://gitlab.com/fraserphysics/hmmds Once you install the source software, you can build a pdf for the book by typing "make book". I think that makes it reproducible research.
fraserphysics
·8 か月前·議論
Yes! There's more oil in the ground than we should ever burn. The places where it's cheap to get out are ruled by unpleasant people. Shale limits the price they can charge. Yea shale. However, low prices encourage putting CO2 in the air. Boo shale. I wish we would find a better way to reduce use than paying unpleasant people high prices.
fraserphysics
·9 か月前·議論
I read the NY Times article about this earlier this morning. I thought it was not very good. I came to HN to see if it had something better. It did. The linked article is also at something like a high school level, but it gave me (retired PhD Physics) a good idea of the experiment and the theory. Thanks.
fraserphysics
·9 か月前·議論
Please take a look at the most recent draft of my book "Hidden Markov Models and Dynamical Systems" https://www.fraserphysics.com/book.pdf In the first chapter I talk about a chaotic model for laser dynamics, and in the last chapter I use the same ideas to analyze ECGs.

The code and text are at https://gitlab.com/fraserphysics/hmmds. From a Nix command line, "make book" builds the book in about 10 hours.

I'd be grateful for any feedback on the book or the software.
fraserphysics
·10 か月前·議論
I think it was Larry Summers.