Oxygen, nitrogen, CO2 and argon make up 99.94% of the atmosphere. The remaining 0.06% has 5ppm is nearly 1% helium. That's up 200x from the original concentration and is well above the 0.3% that is sometimes quoted as the limit for economic extraction of helium (and well below the 7% of some natural gas).
Furthermore, the leftover gas is also already cold. It is absolutely true that 85K isn't very close to the boiling point of helium, it is a lot closer than starting at the temperature of gas at the well head.
The gotcha is almost certainly going to be that an ASU probably doesn't liquify most of the gas it takes in. That means that the exhaust gas will only be slightly enhanced.
All that remains is an algorithm to reliably determine which programs do "shady shit". How is it that you determine that Microsoft updates have not been tampered?
(insincere) apologies for the snarky tone. You are making light of a very hard problem and default deny until confirmed by the user isn't a bad first approximation.
Because the app may generate more than one descriptor for it or perform more than one read or write operation in the normal course of usage. If I open a document, and come back to it 6 hours later and click the save button, I would expect it to save the document.
This rules out entire classes of app and would make using a computer a miserable experience.
For example let's say you want to make an app that every day writes a backup to a particular location e.g. 1Password can do a daily backup of your encrypted passwords to a backup location.
Or, let's say you want to make a GUI around a command line program that stores its config as a dotfile.
Without a way to save access to file system locations persistently, apps would be forced to constantly shove open panels in your face all the time.
Expiration depends on how the app has implemented the request for access. Granting access creates a security-scoped bookmark. The app can store it and use it the next time access is required which will bypass the prompt and the bookmark will remain valid in perpetuity (or until tcc reset), or the app can not store it and request permission every launch.
It doesn’t expire, you can even move the file and you can update the bookmark to follow the move.
There are legitimate reasons to give an app persistent access to a file or directory. Maybe you want it to write to a particular directory in your iCloud storage or whatever so it syncs without having to select the directory every time. A note taking app for example.
No, it shouldn’t. There are real reasons to give persistent access to a particular directory. Maybe you want your note taking app to put all notes in a directory for iCloud/dropbox/google drive/some other sync service.
I am baffled that anyone thinks implication-of-action ambiguity and hidden security states without obvious controls, are acceptable security practices.
I think that this was a great intro into Kalman filtering.
The one important point that I think warrants a small paragraph near the end is that the example you gave is a way of doing forecasting (estimating the future state) and nowcasting (estimating the current state), but Kalman filters can also be used retrospectively to do retrocasting (using the present data to get a better estimate of the past).
Nowcasting and retrocasting are concepts that a lot of people have trouble with. That trouble is the crux of the Kalman filter ... combining (noisy) measurements with (noisy) dead reckoning gives us (better) knowledge. For complete symmetry, it is important to point out that we can't just use old measurements to describe the past any more than we should only use current and past measurements to define our estimate of the present.
If you are in an embedded world, the tradeoffs are quite mild. Mostly these center around library availability and that is often gated by use of reflection.
If you are thinking that this is a way to support mainstream go programming, you will be sorely disappointed.
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