I was able to get a copy of this via interlibrary loan some time ago, after finding much better citations.
btrettel
Karma: 623
Got this from a website that sells copies of Russian dissertations.
I definitely pulled out all the stops on this dissertation, and learned a fair amount in the process. If you’re not living in Russia, and looking for a Russian dissertation, I would be a good person to contact. I can’t get you the dissertation but I can put you in contact with people who can.
I don’t see how that would be a problem. Perhaps I’m missing something, so if you could explain I’d be appreciative.
Usually the problem is that wavelengths smaller than the grid size obviously can’t be resolved. A class of turbulence modeling approaches can help with that to a certain extent. This class of methods is called “large eddy simulation”, or LES for short. You apply a low pass filter to the governing equations and then develop models for “unclosed” terms. In practice this is typically done less rigorously than I’d like, but it’s a valid modeling approach in general that should see more use in other fields. (Turbulence modeling is an interesting field in itself that a rational person might be interested in studying simply for the intellectual challenge.)
You’d be more likely to get some kind of waves that propagate at fixed speed along the grid, giving you a privileged rest frame, like in the old discredited theories of aether.
I’ll try to steelman Florian_Dietz.
I don’t know much anything about relativity, but waves on a grid in computational fluid dynamics (CFD for short) typically don’t have the problem you describe. I do vaguely recall some strange methods that do in a Lagrangian CFD class I took, but they are definitely non-standard and I think were used merely as simple illustrations of a class of methods.
Plus, some CFD methods like the numerical method of characteristics discretize in different coordinates that follow the waves. This can resolve waves really well, but it’s confusing to set up in higher dimensions.
CFD methods are just particularly well developed numerical methods for physics. From what I understand analogous methods are used for computational physics in other domains (even relativity).
I only skimmed this post, but I want to point out that most computational physics (and engineering) uses discretized space and time much as you’ve described. This is not new, just how things are often computed in practice.
Whether or not reality is discrete in this sense is beyond my knowledge as an engineer, but I have had conversations with physicists about this. (As I recall, it’s possible, but the spatial and temporal resolution would be very small.)
Also, there are some exact solutions for discretized physics like this, but in general it’s harder to do. Plus, because physical laws tend to be written in continuous form, very few people look for exact solutions like this.
makes all the contradictions go away
Not really. In computational fluid dynamics, converting to discrete equations can introduce major problems. One important problem is conservation. Depending on how you formulate your discrete equations, mass, energy, etc., may be no longer conserved and might not even be approximately conserved. “Equivalent” continuous equations would not have the same problem. And I would not say solving this problem is trivial by any means, though I know at least one way to do it.
I can see that I misremembered the lecture. Seems to be an application of Bayes as Lumifer suggested for the basic approach. Other more complex approaches were also discussed.
While I don’t have my notes in front of me, I do recall from the decision analysis class I recently took that log score is related to the weight one would give to one forecaster among several when combining forecasts. Unfortunately it does not appear that the professor uploaded the slides on ensemble forecasting, so I can’t provide any more right now. I am emailing the professor. Thought this would help in the meantime.
Thanks for pointing out that post by nostalgebraist. I had not seen it before and it definitely is of interest to me. I’m interested in hearing anything else along these lines, particularly information about solving this problem.
Citation: Богданович И. И. Влияние подготовки топлива в форсунке на тонкость распыла. Дисс. канд. техн.наук. М., 1948, 136 с. (Bogdanovich I. I. Influence of fuel preparation in the nozzle on the spray fineness. Diss. cand. Technical Sciences. Moscow, 1948, 136 pp.)
library URL: http://search.rsl.ru/en/record/01000176055
Old Russian dissertation. As far as I can tell, this is only available at the Russian State Library. If anyone could visit that library and scan the dissertation, I’d be appreciative.
I’d be more than willing to fulfill a similar request of anyone who could visit this library and get a good quality scan.
What I have tried: Google, Worldcat, Libgen, and other search engines have not returned this dissertation. My university interlibrary loan office participates in a special program to obtain foreign dissertations (usually on microfilm). They were unable to get a copy of this. I have also tried purchasing this dissertation on disserCat, but there is no scan of the dissertation available at present, so it is not for sale. I also emailed another Russian website which claimed to be able to sell the dissertation, but I never received a reply.
See also:
The author was kind enough to scan their thesis and email me a copy.
While only having read the abstract at the moment, this seems to confirm my belief that one should generate a large amount of hypotheses when one wants a more rigorous answer to a question. I’ve started doing this in my PhD research, mostly by compiling others’ hypotheses, but also by generating my own. I’ve been struck by how few researchers actually do this. However, the researchers who indeed do consider multiple hypotheses (e.g., in my field one major researcher who does is Rolf Reitz) earn greater respect from me.
Also, hypothesis generation is definitely non-trivial in real scientific domains. Both generating entirely new hypotheses and steelmanning existing hypotheses are non-trivial. It doesn’t matter if your scientific method will converge to the right hypothesis if it’s in your considered set if most sets don’t contain the “correct” hypothesis...
Very interesting paper. I will be reading this closely. Thanks for posting this link.
Poetry, along with some other art forms, always struck me as inherently uninteresting to the point where I find it hard to believe anyone actually enjoys it. I see some people who are obviously moved by poetry, so clearly I’m just at one end of the spectrum. To each their own.
Visited the Library of Congress this past Wednesday. I’ll be going to the Library of Congress several times this summer, so reply to one of my comments here if you want anything in particular at the Library of Congress.
It was a fairly productive day, as I think I’ve found a good strategy for avoiding the phone book people at the scanner. For some reason, there’s often a ton of people who do nothing other than look at old phone books. I assume this is for some sort of private investigator business or something along those lines. I never asked. Anyway, they tend to procrastinate and use the one overhead scanner starting around 2 to 3 pm, so it’s best to do as much book scanning before them. My current strategy is to do my book scanning before 2 and then switch to microfilm, as I rarely ever see anyone using the microfilm viewers or scanners.
I hoped it would be possible to extract the data from the diagram, but no, the jpg in the pdf is sufficiently low-resolution that it doesn’t work.
I have been compiling a lot of data for part of my PhD and this is a lot more common than I am comfortable with. Personally, as a reviewer I’ve decided to outright reject papers that don’t allow one to extract the data. My preference would be requiring publishing the data straight up, but I can see an editor viewing this as unreasonable, or an author not knowing how to publish data.
With this being said, it’s worth asking authors for raw data. My prior on receiving raw data from an author is low, particularly if the study is older. You have nothing to lose, however, and you will sometimes gain respect for helpful researchers. One professor I emailed for about 25 year old data searched his office thoroughly, found the data I wanted on some old floppy disks, got a floppy drive working, and emailed me the files. That was a not insignificant amount of their time, and I’m very appreciative for it.
Also, frequently theses and dissertations have tabulated data. Beware of typos in the tables. Always perform some sort of sanity checks on the data. Checking the tables against the figures is one approach.
r/UCDavis has confirmed that this can’t be downloaded from HathiTrust if you are a UCD student. Someone there pointed out a copy at UC Berkeley that might be obtainable. Trying that now.
I’ll be visiting the Library of Congress next week for one day. Let me know here if there’s anything in particular you might want me to look at or scan there.
To keep this manageable, I’ll only accept requests that appear difficult to obtain elsewhere. If it looks like you can get what you want via interlibrary loan, try that rather than asking me. If you are not affiliated with a university then I’d recommend talking to a librarian at a public library about this. Seems many public libraries will do interlibrary loan for free or a fee.
Likely I’ll make a second trip to the Library of Congress in August, too.
This reminds me of something my father, a retired patent examiner, told me once. For a certain legal procedure the US Patent Office has a form letter a lawyer can use that contains all of the relevant information in a convenient format. My father was amazed by lawyers who refused to use it and instead wrote their own version of it. This seems like a waste of time for both the lawyer and examiner. When my father asked why, at least one lawyer told him that they believed the standard form had legal implications they didn’t like, though my father insisted that case law made it clear that was wrong here.
Another (cynical) hypothesis is that these lawyers are paid by the hour and that they actively wanted to waste time.
R. D. Monson, “Experimental studies of cylindrical and sheet jets with and without forced nozzle vibrations” M.S. thesis, Dept. of Mech. Engr., Univ. of Calif., Davis (December 1980).
UC Davis refuses to loan this for unknown reasons. What I find odd is that it has already been digitized. UC Davis students might be able to download it here. Let me know if you can download it.
Good point. Ideal would be entering a number. If I recall correctly the actual guidelines are written in terms of MET-minutes, a weird exercise specific unit of energy. The entire “moderate intensity exercise” thing is a simplification of the actual recommendation. I’m not sure how much participation would decrease if we generalized from binary in this way.
Amusingly enough, I got into the conference this year early. This seems to be a small piece of evidence for my hypothesis that these sorts of applications often work as lotteries.