Can I play an English horn part with a viola?

Question: I want to perform music in class for a Shakespeare play. Can I play an English horn part with a viola?
Answer: I assume you're asking whether you can play an English horn part on aviola, because you have a viola player at your disposal and not an English horn player.
It's possible, but there are a few problems:

The viola player will be used to reading in alto clef, not the treble clef in which the English horn part is written.
The English horn is a transposing instrument, and all music for is it written a perfect fifth higher than it sounds. This means that, when the violist plays the English horn part, they will sound a perfect fifth higher than they should (!).

It's going to be difficult to hand a violist treble clef music written at a different pitch level. Doing this properly would require some re-writing of the English horn part so that a violist could read it and perform it at the correct pitch level.
Comment: Just want to point out that competent violists can play treble clef without issue, and transposing down a fifth is a pretty straightforward practice. Given enough notice, the violist could just sketch out the notes on the part.
Comment: @jjmusicnotes or the violist could "think" it's in alto clef and, combined with the transposition, be off by a fourth :-)
Comment: Give the music and viola to a violinist! The strings of a viola are pitched a perfect fifth below that of a violin (however, viola music is written in concert pitch so it is not considered a transposing instrument, though a violinist might feel otherwise on his first attempt at playing a viola!)
Answer: Some of the early English Horn music can be found written in Alto clef in the sounding pitch of the instrument. If the music is in the Alto clef, then the Viola should be able to read it directly. The Viola has a pitch range that can play all of the notes that the Horn can.
Answer: There are multiple aspects you would need to determine to see if one instrument can replace another. I will list some in the order of importance.

Is this even necessary? Is the part actually important to the piece? A lot of pieces are written with parts that may be omitted. Even if the instrument has a solo, often cues will be written for other instruments. And, of course, you may be able to find someone who can play the correct instrument.
Sound: Do the instruments sound similar? If not, does the difference sound okay to you? This really is a personal judgment, and depends on the instrumentation of the entire piece.
Range: Do the instruments share enough of their of their range to play the piece? And, if they do, does the replacement sound okay in the entire range of the song? If not, then can it be dropped or raised an octave and sound okay? (This is usually only true if the instrument is playing solo or possibly duet.)
Transposition: How easily can the replacement instrument read the actual music in the right pitches? If both instruments play the same pitches (e.g. a C on one instrument sounds the same as a C on the other one) and they are written in the same clef, this isn't a problem at all. If not, the difficulty depends on your approach.

The failsafe solution is simply to rewrite the music. The only caveat is that, in certain situations, one may be required to use original scores only.
If this is not possible, then it depends on two things: the skill of the performer to transpose on sight, how long they have to practice, and how difficult the transposition actually is.

Articulation: Can the target instrument actually make all the variations of sounds that the original? I put this last because it is the least likely to be a problem, as most instruments can do some semblance of the same articulations, assuming the original is a single note instrument and the target instrument can fully sustain a note.

Your specific case
I will assume that you have already considered number 1, so I will first address number 2. I would argue the two instruments sound fairly similar, especially with vibrato. The viola has bit more of a richer sound, while the English horn is more piercing, but they overlap a lot. The main issue would be with instrumentation: the viola can get lost in other string instruments while the English horn tends to come out above. However, having other strings play softer and the viola play louder may overcome this limitation.
Number 3 is unlikely to be a problem, as the range of the English horn is close to and completely contained within the range of the viola, based on this chart. The viola's range is C3 to E6. The English horn's range is B3-G6, but it plays a fifth lower than written, so that's actually concert E3 to C6.
Number 4 is the big one. It's possible the music is already written in alto clef. If so, then congratulations! You can just play it all as written. When the English horn is written in alto clef, the notes are the concert pitches, which is the same as for the viola.
Otherwise, it will be written in the treble clef. If you have access to music writing software, it would be easy (if possibly time consuming) to simply copy the music into the program, and then use the transpose feature. You would need to transpose down by a perfect 5th (7 semitones), and change the clef. Then you just need access to a printer or possibly a tablet.
If that is not something you (or the performer) can easily do, however, don't fret. The transposition is a fairly easy one.1 All the player needs to do is add a line below the staff, add a sharp or take away a flat in the key signature, and treat the clef as different. If they wish to write this on the score, they can draw in the addition line, clef, and accidentals in pencil, and then use a highlighter to highlight the new line and the four lower lines, to remind them not to count the top line. Or, if they are able, they could white out or erase the top line.
And number 5: as I said, this is rarely a problem. I cannot think of any articulations that the English horn can do that the viola would not be able to mimic. (The opposite is not true, of course, due to the viola having multiple strings and harmonics and infinite sustain.) It may be more or less difficult, but it should be doable. The only restraint is the ability of the performer.
[1] The reason this is true is that the English horn plays a fifth lower than concert pitch. Hence a second line G is actually playing middle C. In the alto clef, middle C is the third line. So adding one line and fixing the clef and key signature fixes the issue. Many players can handle the mental change on their own, especially if they have time to practice.
Comment: As to your footnote: an excuse for the OP to learn LilyPond and produce the transposed/shifted part!
Comment: @CarlWitthoft LilyPond Master Race! ;-)
Answer: Yes.  A viola can play those notes, range-wise.
But you can't just hand a viola player an English horn part.   Different clef, different transposition.   English horn is 'in F'  written a fifth higher than it sound in treble clefs.  Viola is non-transposing - the notes you see are the notes you get - and it normally reads alto clef.
Talk to your viola player. Show them the English horn part. If it's a fairly simple part and they're an experienced player you might get 'Sure, I can cope with that!'
Otherwise you've got some writing out to do.   Have you got a notation program on your computer?  The free MuseScore will do very nicely.    Set up an English horn stave and a viola one.   Enter the notes into the former, copy/paste into the latter.  Job done.
If you have to do it by hand, and find transposing from treble clef 'in F' to alto clef concert pitch at all confusing, get hands-on advice.  Any attempt to explain here, in words, could be equally confusing :-)


Understanding default bitcoin wallet in bitcoind

Question: I am new to block-chain, so please bear with my questions. I need to understand the basics of a bitcoin-wallet.
So I have setup a bitcoin full node using bitcoind in running in testnet mode. As I understand that by default a wallet is created. Now when I am trying to get the address of the wallet by this command bitcoin-cli -testnet getaccount "", I am geeting an empty list.
So is there no default wallet as such, also how do I create a new wallet? As I understand that a bitcoin wallet is basically a pot which holds several child addresses?
Answer: getaccount command was deprecated in Bitcoin Core 0.18, the wallet uses "labels" now.
When the wallet was created, it created a seed for you. This is used to generate the addresses in a BIP32 heirarchy. To generate the first address, you can use the getnewaddress command, followed by an optional label (to save the address in the address book), and an optional address type. E.g.
$ bitcoin-cli -testnet getnewaddress my_first_address

As I understand that a bitcoin wallet is basically a pot which holds several child addresses?

A Bitcoin wallet is generally considered software that manages your Bitcoin addresses and transactions, as well as your private keys to those addresses. In Bitcoin Core it is also used to describe a heirarchy of addresses with their own unique seed. Addresses used within a "wallet" on Bitcoin core are all derived from the same master key and seed. In fact you can have multiple wallets using the same installation of Bitcoin core, see createwallet


Yosemite Storage Analysis

Question: I have Yosemite on MacBook Air and continuously get en error about storage usage. It keeps saying there isn't enough empty space on disk. About this Mac says that I have 65.96GB of other type files. When I get info about home directory it says 57.69GB is the size of home directory. However when I sum up the sizes of each directory under home, it is only about 12GB of data. I can't find where the remaining 46GB is. Any ideas?
Answer: Finally found it :)
Under home directory Library has all the data and most of them came from mail app which includes downloaded imap copies and attachments. I erased them by using mail app and everything is fine for now.
Comment: Please add the whole Path to the Library folder, and explain exactly how did you delete the files - from Finder or from Mail itself.

Yosemite Storage Analysis


Why is LogLoss preferred over other proper scoring rules?

Question: It seems anytime people care about estimating probabilities accurately they choose LogLoss as the evaluation metric. But there are many other evaluation metrics which will prefer accurate estimation of probabilities (and not only ranking or performance at some cut-off). Including RMSE (on the continuous model score vs 0/1 actual).
Obviously LogLoss penalizes over confidence very heavily, Why is this desirable? When is it not?
Comment: With a binomial model, what you call logloss corresponds to maximum likelihood estimation. That is the real reason.
Comment: Preferred $\ne$ best. For example, check this recent paper showing that squared error may work better in some cases for binary classification problems https://arxiv.org/abs/2006.07322
Comment: @Tim: it probably depends on the alternatives, or the misspecifications we want to distinguish from the true probabilities. For instance, [my answer here](https://stats.stackexchange.com/a/469059/1352) has two plots at the very bottom, of the log and the Brier score for transformations of the true probability. Against these particular mispredictions, the Bier score probably works best in guiding us to the correct prediction at the minimum, because it's nice and symmetric.
Comment: Very much related: [Logarithmic loss vs Brier score vs AUC score](https://stats.stackexchange.com/q/470380/1352)
Answer: Arguments for the log score
On the one hand, as kjetil b halvorsen writes, the log loss is just a reformulation of the log likelihood, which statisticians are very used to maximizing, so it is simply very natural as a KPIs. (A somewhat more common convention is to minimize the score, in which case, one takes the negative log of predicted probabilities, but the same point still applies.)
On the other hand, in the single-class classification case, Merkle & Steyvers (2013, Decision Analysis) point out that the log score is just one member of an entire family of strictly proper scoring rules, which are indexed by two parameters $\alpha\geq 0$ and $\beta\geq 0$. Particular values of $\alpha$ and $\beta$ can be set based on the cost $c$ of misclassifications (based, in turn, on comparing probabilistic predictions to a threshold). Smaller values of $\alpha+\beta$ correspond to higher uncertainty in $c$... and the log score just happens to be the member of the family with $\alpha=\beta=0$. So at least in this classification case, you could say that the log score is a reasonable choice (within this family of scoring rules) that corresponds to the highest uncertainy or agnosticity in the misclassification cost.
On the third hand, Benedetti (2010, Monthly Weather Review) considers three properties a scoring rule should have:

it should be additive when adding a new event
it should only depend on the probabilities assigned to events that actually occur and can be observed ("locality")
and it should be proper (more strongly, Benedetti requires differentiability in predictions and a derivative of zero at the true probabilities)

Benedetti (2010) then proceeds to show that the log loss is the only scoring rule that satisfies these conditions in the case of finitely many possible events.
(To be honest, I don't quite follow Benedetti's derivation; specifically, I don't see how he arrives at equation (7). But I'll put this edit in here as a pointer so smarter people than me can look at the paper.)
Benedetti (2010) then explores connections to information theory and Kullback-Leibler divergence between the probabilistic prediction and the actual outcome distribution. He draws attention to one disadvantage of the Brier score: it depends on probabilities predicted for unobserved events and thus violates the locality requirement. Specifically, assume we have $R=3$ possible events and two different probabilistic predictions, $(0.2,0.4,0.4)$ and $(0.2,0.3,0.5)$. Suppose further that the first event actually occurs. Note that both predictions assign the same probability of $0.2$ to this event. Locality would require both predictions' scores to be identical, since they only differ on predicted probabilities for unobserved events. However, the multi-category Brier score for the first prediction is
$$ (1-0.2)^2+0.4^2+0.4^2 = 0.96 $$
whereas the score for the second prediction is
$$ (1-0.2)^2+0.3^2+0.5^2 = 0.98. $$
However, as Benedetti (2010) points out, the Brier score is a second-order approximation to the logarithmic skill score, which explains some of its appeal.
Finally, one more argument for the log loss that I'm taking from Benedetti (2010, p. 208): if an event occurs which we had predicted to be completely impossible, $\hat{p}=0$, then the log loss is infinite, with no chance of being "saved" by other better predictions. Thus, using the log loss truly forces us to consider the possibility of extremely rare events and not just sweep them under the table. The Brier score, in contrast, is much more relaxed about observing events predicted to be impossible.
For instance, Jewson (2004, arXiv:physics/0401046v1) gives the following example: assume a simple two-class prediction situation. The event occurs with a true probability of $p=0.1$. We have two competing predictions: the first is that the event is impossible, $\hat{p}_1=0$, the second overestimates the true probability, $\hat{p}_2=0.25$. Then the expected Brier score for the first prediction is
$$ 0.1\times 1^2+0.9\times 0^2 = 0.1 $$
whereas the expected Brier score for the second prediction is
$$ 0.1\times (1-0.25)^2+0.9\times 0.25^2 = 0.1125. $$
So the Brier score would actually prefer the first prediction, which is completely off base in that it considers an event with a $0.1$ probability of occurring as completely impossible. This does not make intuitive sense.
Arguments for the Brier score
Of course, the Brier score also has advantages. For instance, the log score explodes if we observe an event that we thought would be impossible, because we then take the log of zero. To some, that's a feature (see above), to others, it's a bug. The Brier score will still be defined if an "impossible" event occurs.
The Brier score is conceptually very close to the Mean Squared Error, and can in fact be expressed as such (between a vector of probabilistic predictions and a 0-1 vector of which class actually occurred). This is easy to understand.
Selten (1998, Experimental Economics) offers four axioms we could require a scoring rule to fulfill:

it should be symmetric if classes are reordered
adding a class with zero predicted and true probability should not change the score
if the true class probabilities are $p=(p_1, \dots, p_k)$ and we predict $\hat{p}=(\hat{p}_1, \dots, \hat{p}_k)$, then the score should be positive (i.e., "bad", see above on conventions about positive and negative orientation) - this is strict properness, which Selten (1998) calls "incentive compatibility"
if the true class probabilities are $p$ and we predict $\hat{p}$, then the score should be equal to the case where the true probabilities are $\hat{p}$ and we predict $p$ (symmetry; Selten calls this "neutrality")

Selten (1998) then shows that the Brier score is the only one that satisfies these axioms, up to scaling. The log score, of course, violates the fourth requirement, because in general
$$ p\log \hat p \neq \hat p\log p. $$

So one way of looking at it is whether we prefer Benedetti's argument that a scoring rule should be "local" (i.e., not be influenced by predicted probabilities for unobserved events), or Selten's argument that it should be symmetric (i.e., give the same result if we exchange the predicted and the true probability vector). In the first case, we should use the log score, in the second case the Brier score.
I personally find Selten's requirement of symmetry (the fourth bullet point in the Brier section above) unnecessary, and I consider the log score explosion a feature and not a bug (see above). Thus, I prefer the log score.
Comment: Really good edit, much better answer now, thanks. The symmetry argument is new to me  and elegant but I agree it isn't very persuasive. The logloss explosion is what really bothers me and seems only useable when adding a significant extra magic epsilon. (e.g 1/(sample size) )
Comment: If we change your example a bit it probably changes what makes intuitive sense. For instance, is 0% or 25% a better estimate of a random person's chance of winning the lottery? The only difference between this and your "estimate a 10% chance at 0% or 25%" example is the actual likelihood and yet most people's intuition changes. In some domains, 0% is the better estimate for very rare events, and in others "impossible" is a very bad estimate for "possible".


Conditionally display a CEWP depending on form content type?

Question: I have a request list with different content types set up for different types of request.  I would like to show a different CEWP at the top of each form depending on which type of request is being made.  I do not have access to SharePoint Designer.  Is there another way to create different .aspx pages for different content types?  OR can I conditionally show different CEWPs on the single newform.aspx?   Currently I link to the different content types NewForm.aspx by appending the content type ID to the URL.  Thanks
Comment: Why different CEWPs, and not the same CEWP that shows different content depending on the content type?
Comment: +1 for @Christophe... this make sense as it would be easier to control content in single CEWP than adding different CEWP for different content type..
Comment: Yes that would work.  I don't 'need' to have two separate CEWPs.  How can I show different content in the one CEWP, depending on content type?  Thanks in advance
Answer: Unless you create your own URL to NewForm.aspx without parameters,
the ContentTypeId is by default present as a QueryString parameter.
So you can add some JavaScript to that single NewForm.aspx (edit in advanced mode)
just before the table of the form, that matches by ContentTypeId and prints a header.
If you don't have SharePoint Designer add a ContentEditorWebPart above the Form in the page.

Always get the correct ContentTypeId
After pageload the ContentType info is always present in:
WPQ2FormCtx.ItemContentTypeId
and
WPQ2FormCtx.ItemContentTypeName

But you better make sure you reference the correct WebPart (WPQ2 most of the time)
Comment: Thanks Danny.  I understand how to add code to a page using a CEWP webpart, but JavaScript is beyond my abilities.  Does that code cause a different heading to display for each content type?  ie if content type id = '0x0100223....010019ABEA5C55C59D4383F98D5A938894D8' , the form heading will be 'Expense'?
Comment: Yes. I added some comments. Use [JSFiddle](http://jsfiddle.net) to play with JavaScript snippets. Note that JSRequest is SharePoint specific code.
Comment: Hi again, I'm making progress, thanks, but could you show me how to stop an additional title being added after each time I create a new request?  After I have made a few requests, the following gets added to the bottom of the code: New: Domestic / Trans-Tasman
New: Domestic / Trans-Tasman
New: International
Comment: Yes ``document.write`` will always add a line. You have to learn more JavaScript to add a ``DIV`` element once and change the ``innerHTML`` of that ``DIV``


How to find usable files among recovered files?

Question: When you use a data recovery program like Recuva, it can "recover" lots of files which lots of them are just unusable with random data in them but somehow having correct filenames. Is there any way to automatically detect those files or files having meaningful data but needing repairs and delete the rest of the files which are junk?
Comment: Not exactly a duplicate, but may be useful: https://superuser.com/q/432535/432690 .
Comment: @confetti I was looking for a way to do it in Windows as I'm not too much familiar with Linux unfortunately. But I marked it and thank you.
Comment: @confetti There's a Windows program called TrID File Identifier and it works great and also has a command line feature. Do you think we can write a simple program to automate checking every files in a directory by TrID? Here's the [link](http://mark0.net/soft-trid-e.html) to the program.
Comment: I found http://gnuwin32.sourceforge.net/packages/file.htm this, which claims to be "File for windows". Maybe that is a help. TrID looks great for the job, but I can't find a way to output only the extension or mime-type. Another idea would be to use a live linux distribution on an USB stick. It's really quick, doesn't change anything on your system (runs from USB) and after you ran my script you can switch back to windows.
Answer: Under linux, the utility file might be worth looking into. It "tests" each file you pass to it using three different kind of tests instead of relying on the filename's extension. (See man file for an explanation of the different tests).
Here's an approach for testing every file in a directory and copying it into a new folder if it's a JPEG image.
#!/bin/bash

mkdir useful

for cfile in *; do
    fileres=$(file -b --mime-type "${cfile}")
    if [[ "${fileres}" == "image/jpeg" ]]; then
        cp "${cfile}" "useful/"
    fi
done

Run this script in the directory with all your recovered files, and it will copy only jpeg files to the useful directory. If you're looking for other filetypes simply replace the image/jpeg in my script with the mime-type of the files you are interested in.


Microsoft Visual Studio 2008 Express edition - APPCRASH

Question: I am not able to execute my VC++ program on Microsoft Visual Studio 2008 Express Edition. It displays an error saying the .exe has stopped working. The problem event name is APPCRASH. Could you please tell me how to fix it. I am unable to run any program.
Answer: Have you try to start the application in the debugger? Or you can to take a look into the problem signature, which should be offered by the error dialog.
Kim


VB Type setting for a SHA512 hash

Question: I have the following function for generating sha512 hashs. The hash is generated successfully, but is causing this error when the resulting string is passed to other functions:

Input string was not in a correct format

When debugged the variable holding the returned hash (set as string) is empty. I have tried changing the type to int, int64 and byte (array and standard variable) in the function and in the calling code, which causes various other errors. How can I change the datatype correctly to solve this?
Function create_hash(ByVal password, ByVal salt)

Dim salty As String = password & salt

'convert salty password to binary to feed into hash function
Dim encText As New System.Text.UTF8Encoding()
Dim btText() As Byte
btText = encText.GetBytes(salty)

'Dim data(btText) As Byte
'create password hash
Dim result() As Byte
Dim shaM As New SHA512Managed()
result = shaM.ComputeHash(btText)

Dim return_result As String

For Each Item As Integer In result

    return_result = return_result & Item

Next

Return return_result
End Function

Calling code:
Dim i_h_pass As String
Dim i_pass As String = pass.Text
            'handle password generation (matching passwords checked at validation)
            Dim newHash = New hashing
            Dim salt As String = Convert.ToString(newHash.create_salt)
            i_h_pass = Convert.ToString(newHash.create_hash(i_pass, salt))

edit:
the create_salt function has also been checked - it works perfectly and returns a random integer, returned as string for conveince
Answer: Fixed with:
Function create_hash(ByVal password, ByVal salt)
Dim salty As String = password & salt

'convert salty password to binary to feed into hash function
Dim encText As New System.Text.UTF8Encoding()
Dim btText() As Byte
btText = encText.GetBytes(salty)

'Dim data(btText) As Byte
'create password hash
Dim result() As Byte
Dim shaM As New SHA512Managed()
result = shaM.ComputeHash(btText)

Dim return_result As String = BitConverter.ToString(result)
    Return return_result
End Function

Dim return_result As String = BitConverter.ToString(result)
Being the change

VB Type setting for a SHA512 hash


what are the thing needed for doing illustator sketup

Question: what are the thing needed for doing illustator sketup I MEAN LIKE LAPTOP OR COMPUTER AND MOSTLY I SEE THE PAD USED BY MOST OF THE DESINGER  WHAT IS THAT AND WAHT IS PURPOSE OF THE PAD THAT IS USED FOR SKETCUP IN ILLUSTRATOR ?????? SORRY IF THIS IS SILLY QUESTION
Answer: If you mean what's a decent setup for using Illustrator then I'd recommend a laptop with a decent amount of ram and a good trackpad. If by pad you're referring to a graphics tablet like a Wacom then yes it does help but it's not essential. Illustrator is vector based so there's less traditional painting action needed like Photoshop or similar raster based packages so as long as your laptop has a decent sized trackpad you should be ok.
If you have Photoshop and want to move onto Illustrator I'd suggest getting yourself comfortable with the pen tool as once you get Illustrator this will be your primary tool.
My understanding is that if you are importing Sketchup files into Illustrator you will need Sketchup Pro. I hope this explanation helps you a little.


Word for an organization formed from a collapsed one?

Question: I was looking for a word that could be used in the context of "(organization 1) and its __________ organization, (organization 2)" that means 'created by members of the first organization with similar ideas when the first organization was destroyed'. I already saw subsidiary, but that wasn't quite what I was looking for, since the first organization did not survive the creation of the new one. Thanks for your answers.
Answer: Spin-off is one possibility commonly used. In business, one leverages one's experience to create something new.
But if you are looking at metaphorical terms 'caldera' come to mind.

A caldera is a cauldron-like volcanic feature usually formed by the
  collapse of land following a volcanic eruption.

Phenix is another:

A Phoenix is a unique bird in classical mythology that lived for five
  or six centuries in the Arabian desert, after this time burning itself
  on a funeral pyre and rising from the ashes with renewed youth to live
  through another cycle.
Comment: [*A "**phoenix company**" is a company that, at the time before or within five years after the commencement of liquidation of a failed company, is known by the same or a similar name as the failed company.*](https://www.google.com/search?q=%22a+phoenix+company+is+a%22&btnG=Search+Books&tbm=bks&tbo=1) There are two separate "definitions" for what *Palmer's company law* drily identifies as "colloquial language". It works for me.
Comment: @FumbleFingers amusing that that is actually a term.
Answer: There is a legal concept of successor that often is applied to organizations

A successor is a person or entity who takes over and continues the role or position of another.
and
A corporate successor is a corporation that takes on the burdens of a previous corporation through merger, acquisition, or other means of succession.

USLegal.com
Similarly, one of Macmillan's definition of successor is

used about something such as an organization or machine that replaces something that did the same job before
  The Russian Federal Security Service is the main successor to the KGB.
Answer: I think newco  is the term generally used, though it does not necessarily imply that the old company is no longer existing.

(business) A new company, especially one spun-off from or replacing an existing company as a legal fiction to maintain ownership over an entity while separating it from the old company financially.

(wiktionary)
Comment: I would reserve *newco* for firms which are formed or re-formed by the owners of the previous firm; for example, General Motors Company LLC is the newco for General Motors Corporation (its bankrupt forebear, which still exists, with all its bad debts, as the Motors Liquidation Company). In contrast, Eastern AIr Lines Group has basically nothing to do with Eastern Air Lines Inc., besides the trademarks it has accumulated. It is a namesake, not a newco. Still, +1 for plucking out this term.
Answer: Offshoot could be used. [Oxford]

a thing that develops from something, especially a small organization that develops from a larger one

It's true that it doesn't imply the parent company is gone, but it also doesn't strongly imply that the parent is still there, like subsidiary does.
Comment: This doesn't have any of the implication that the parent company is gone, though. It seems like the question is looking for something like a phoenix... risen from the ashes of the previous iteration.
Comment: @Catija: See edit
Answer: You could apply reincarnate to your sample usage:

Reborn in another body:
  'he claims that the girl is his dead daughter reincarnate'
Oxford Dictionaries
Answer: Rump works under some circumstances.
Merriam-Webster:

3
  :  a small or inferior remnant or offshoot; especially :  a group (as a parliament) carrying on in the name of the original body after the departure or expulsion of a large number of its members

Happens to countries too: List of rump states.


lightdm won't start after bumblebee install

Question: On an Asus rog with GT960M graphic card running Lubuntu 15.10,
I installed bumblebee (https://wiki.ubuntu.com/Bumblebee) which rebooted fine. Then I updated the nvidia driver by
sudo apt-get nvidia-352-updates nvidia-settings
Then tried running the recommended sudo optirun nvidia-settings
which returned an error so I did the modifications manually. By editing /etc/bumblebee/bumblebee.conf
Then I reboot.
And It doesn't reboot. There is an unusual line :
"error parsing subspace pcc from pcct"
Then I can see splash screen, then I can see a login prompt in which I can login :
I tried to restart lightdm (sudo service lightdm start) but it fails to start (because of too many start attempts).
I tried to purge (reinstall) the nvidia and bumblebee but it didn't work.
I tried recovery modes (which were at  first hidden by splash screen it works but doesn't start gui.
I tried to uninstall lightdm and reinstall.
Internet works on the computer, screen works as I can see text and splash screen on startup and shutdown. I can access disk fine and run commands.
I don't know what I can do to get it to get the GUI work again.
Answer: Answering my own answer :
I managed to get back to the GUI by deleting the
/etc/modprobe.d/bumblebee.conf
file which is not removed as it should have upon bumblebee uninstallation. This file was preventing drivers to get loaded by blacklisting them.


Remove language prefix from base URL

Question: I've installed the Internationalization module in order to make a multilingual site, I've set italian as default language, but there's a problem, the front page is always in english. I've checked the base URL and I've noticed that there's a language prefix, is it possible remove?
Comment: Thanks for your reply neok! I've searched several hours before asking, anyway I've figured out: on  Admin > Configuration > Regional and language > Languages, on the Language Switcher tab Content selection mode needs to be checked on "Selected languages from language block." Have a nice day you too!
Answer: Sometimes I think people do not know how to use search in our time.
You can find the answer on stackoverflow, similar question has already been asked. Have a nice day.
Answer: I think you're mixing a few things here, and I also think that the comment in the question (which should actually have been posted as an answer ...), is only like a partial fix or workaround. What, IMHO; the real issue seems to be here, is that the URL of the homepage has not been defined as a "multilingual" variable, as further explained below.
The relative URL to display as the front page is specified within admin/config/system/site-information . If you want to be able to specify a value for it that is different for each of the site's languages, make sure you have made it a "multilingual" variable (it should say "This is a multilingual variable.") in the description of that variable on that page.
For more details about how to get this done, refer to my answer to How to make content translation available for front page?.

Remove language prefix from base URL


meaning & origin of "wardul"

Question: What is the origin of the surname "Wardul" used in some Asian countries (Pakistan, India...)? Does the word "wardul" mean something in any language? (ex.Hindi, Sanskrit etc etc)
Answer: "Wardul" is Arabic.
The first part "ward" means "rose" (as in the flower).
The second part "-u" was a nominative case marker (meaning the word is the subject of the sentence), but when it was borrowed into Hindustani, it lost its meaning and just became part of the word.
And the last part "l-" was actually a prefix, which was supposed to attach to the next word, and it was a definite article (like "the" in english). Like "-u" it has lost its original meaning, and is now integrated into the word.
So, the whole word means "rose of ...", then  whatever comes next.
Friendly reminder that these kind of questions about origins of words are generally not welcome here, unfortunately, so the question is likely to be closed eventually.

meaning & origin of "wardul"


How to measure if inflation is due to demand pull or cost push?

Question: How does one measure if inflation is due to demand pull or cost push?
Is this related to PPI vs CPI?
Comment: Surely you could just look at changes in the money supply and changes in the amount of goods and services being delivered and see which has changed the most.
Answer: CPI, PPI, PCE, etc. are themselves measures of inflation, which could happen in different sectors of the economy or in different levels of trade and production (see here). So it doesn't really make sense to ask the question as though there is one comprehensive "Inflation" with contributing factors. But CPI is the primary measure and one might use a statistical regression with time series data and a PPI variable along with other controls like population and interest rates to see how PPI change might be passed along to CPI. And ideally you would do this with international data because you could implicitly control for other variables like government policy and culture (fixed and random effects).


90amp breaker to a subpanel for 60 amps

Question: I have a mobile home that is wired for a 90 amp furnace. but didn't have the furnace.. so I purchased one which is  60 amps.
could I take the wires for the 90 amp furnace run it from the 90 amp breaker into the main lug in a subpanel and use a 60 amp breaker for this other furnace?
Comment: Why not just change the breaker to a 60 amp?
Answer: You can simply continue to use the 90 amp wires.  You change the breaker to 60A, they're about $10, but hold on to the old 90A breaker because those critters are expensive.
This depends on the rule that you are always allowed to use larger wires than required.

90amp breaker to a subpanel for 60 amps


Thunderbird 78 won't connect to Exchange-backed IMAP account

Question: Amongst other problems, upon upgrading to Thunderbird 78, it now fails to connect to my personal e-mail account. My personal e-mail account is Exchange-based -- I have no control over that -- but it worked just fine as a regular IMAP account in Thunderbird 68 and on my phone, for example. Has anyone else had any luck with this?
Comment: I've had some success using [DavMail](http://davmail.sourceforge.net/) as a local proxy, but I'd like to avoid this if possible.
Answer: Thunderbird 78 now uses the same default settings like Firefox for TLS connections: Only TLS 1.2+ is allowed by default.
If your Exchange server is a bit older and only support up to TLS 1.1 then Thunderbird is unable to connect to the IMAP server.
The way to make Thunderbird connect again to that server is to allow TLS 1.0/1.1 again by setting the Thunderbird configuration entry
security.tls.version.min = 1

1 = TLS 1.0-1.3 allowed
2 = TLS 1.1-1.3 allowed
3 = TLS 1.2-1.3 allowed (new default value since Thunderbird 78)

Mozilla documentation on security.tls.version
Addendum: Note that because the SMTP server is part of Windows and not of Exchange, TLS1.2 on SMTP is usually supported (SMTP uses the TLS library of Windows but Exchange has it's own TLS libraries which are older).
Comment: Thank you: That did the trick :)
Comment: Thanks for your sharing.
Comment: To change this in version 78. Click on the menu icon (3 bars) > Options > Type "about:config" into the search box and click on "Config Editor". Accept the risk and filter for "security.tls.version.min". Then change the min version from 3 to 1 as stated above.
Comment: Of course, this is not secure. If you have a way to fix the server to support TLS v1.2, it would be a lot better!


How did G.H. Hardy's work contribute to today's public-key cryptography?

Question: I know that Hardy's work in number theory was used by Clifford Cocks in 1973 to develop the basis for public-key cryptography.  What specifically was this work, and how is it used today in cryptography?
Comment: The best thing to do is to read his famous book "introduction to number theory".
You can find over the web some pdf, and I know there is a new edition some years ago.
This is a reference for all those interested in theory of numbers.
Comment: There is another connection with Hardy and crypto. Hardy believed (see, A Mathematician's apology) that number theory  (and in general pure mathematics) should be practiced as an art, ignoring any possible application to our world.
Answer: I've been investigating and can't seem to find any reference to this. Could you say how you found this out?
Cocks's original paper makes reference to several results from number theory without attribution.

An algorithm for determining if a number $M$ is prime with $\log M$ work, but which may fail to provide an answer (I think that this might be Pocklington's algorithm).
A reference to the density of primes being roughly $1/\log M$, which is an observation of Gauss proven by Hadamard and de la Vallée Poussin
The complexity of modular exponentiation being $(\log M)^k$ which is over 2000 years old (see Knuth vol. 2 for some history).
An algorithm for factoring with complexity $N^{1/4}(\log N)^k$ (I think that this might be either Daniel Shanks's SQUFOF or CLASNO method).

G. H. Hardy made a large number of contributions to number theory, but none seem to be directly connected to any of the results used by Cocks.
Answer: I think there may not be any more to this than "despite what Hardy said regarding Number Theory has no applications...". A few links I dug up, none of which indicate any link to any concrete result by Hardy playing a role in this discovery.

Part of the oration by Nigel Smart at the ceremony for honorary PhD for Cocks.

http://www.bristol.ac.uk/graduation/honorary-degrees/hondeg08/cocks.html

In 1940, the famous mathematician G.H. Hardy had remarked that Relativity and Number Theory were the truly great parts of mathematics as they had not been tainted by finding application. Hardy was soon proved wrong about relativity by the advent of the nuclear age, but in 1973 he was still correct about number theory. Clifford was about to alter that position for good by finding the most compelling application of Number Theory.

Excerpt from Simon Singh's book which talks about this Alternative History of Public Key Crypto is below.

https://cryptome.org/ukpk-alt.htm

When Cocks did eventually realise what he had done, it struck him that his discovery might have disappointed G.H. Hardy, one of the great English mathematicians of the early part of the century. In his The Mathematician's Apology, written in 1940, Hardy had proudly stated: 'Real mathematics has no effects on war. No one has yet discovered any warlike purpose to be served by the theory of numbers.' Real mathematics means pure mathematics, such as the number theory that was at the heart of Cocks's work. Cocks proved that Hardy was wrong. The intricacies of number theory could now be used to help generals plan their battles in complete secrecy. Because his work had implications for military communications, Cocks, like Ellis, was forbidden from telling anybody outside GCHQ about what he had done. Working at a top-secret government establishment meant that he could tell neither his parents nor his former colleagues at Cambridge University. The only person he could tell was his wife, Gill, since she was also employed at GCHQ.

Ensuing discussion on uk-crypto mailing list:

https://cryptome.org/ukpk-true.htm
The main item of interest there is Ross Anderson claiming that the papers from GCHQ regarding Cocks' invention were "forged, not originals", since at that point even the existence of the GCHQ was denied.

Comments by Diffie

https://cryptome.org/ukpk-diffie.htm


How to label a digit according to its position in a number

Question: Let's say there is some number like 12345. In Konglish (Korean English), I can label 3 as the hundred's position number and 5 as the one's position number. I don't think this is correct English. How can I label each number according to its position correctly?
Answer: You would say place instead of position, and you would drop the number entirely:

3 is in the hundreds' place
5 is in the ones' place

You could go on in the same way with all the other places: '1' is in the ten thousands' place, or in the number 7.86, 8 is in the tenths' place.
Another alternative is use the word "digit":

3 is the hundreds' digit.
5 is the ones' digit.
Comment: And the same with decimals: In 3.14159, the 4 is in the hundredths place.
Comment: @Colin - no, it seems in perfectly ordinary usage here, among English and Scottish folk. Most common usage is in hundredths of a second.
Comment: @GEdgar: I think if you talked about the "hundredths place" to most British people they'd either assume you meant "the hundreds place" or look at you blankly. My reading suggests that Americans are more likely than we are to talk about tenths and hundredths.
Comment: @Rory: I wasn't clear. Yes, we talk about "hundredths" as independent fractions, but I don't think "the hundredths place" would be nearly as familiar. And the habit I've seen in my reading which seems strange to me is reading "3.14" as "three and fourteen hundredths": I've never heard that here, but I have read it in American novels - though it might just be a particular author that writes like that.
Comment: @Colin: That's how I always heard it said, and how I say it myself.
Comment: So can I say '3' as "the hundreds' place number"?
Comment: @Sang: Actually, you would either say *3* **is in** *the hundreds'* **place** or *3* **is** *the hundreds'* **digit**.
Answer: The term for this is "ordinality". The ordinal number of 2 in 12345 is "second" because the sequence is read from left to right.
http://encyclopedia2.thefreedictionary.com/Ordinality
The terms ones digit, tens digi, hundreds digit, thousands digit, etc... are also correct (probably more so for what you want), though the meaning is different.
Answer: One more alternative would be to say

The thousands digit is 2
The tens digit is 4
Answer: When I learned math in elementary school, we used to talk about the numbers in the way you have described: ones, tens, hundreds, thousands, etc.


the meaning of the sentence quoted from The Scarlet Letter

Question: Could you paraphrase this sentence in an easy style?
: " The Scarlet letter,"he states flatly in a one-sentence paragraph, "had not done its office."
Is there anything to do with office?
Comment: Have you looked up the word **office** in a couple of dictionaries to find out the various meanings the word has?
Comment: https://www.merriam-webster.com/dictionary/office?utm_campaign=sd&utm_medium=serp&utm_source=jsonld See 4 a)
Answer: As you guess, in this case "office" has nothing to do with any physical structure or location.  This actually more closely related to the original meaning of the word.

office (n):  mid-13c., "a post, an employment to which certain duties are attached," from Anglo-French and Old French ofice "place or function; divine service" (12c. in Old French) or directly from Latin officium "service, kindness, favor; official duty, function, business; ceremonial observance"

You can still find this definition in many modern dictionaries, although this use today feels a little archaic or at least formal.  Over time, "office" has come to refer more to the place where one performs official duties, than the duties themselves.
Still, it's not that uncommon:

Although he has been popular, many feel the president lacks the dignity expected of the office.


Canonical form for a pair of quadratic forms

Question: Could anyone recommend a reference to a canonical form for a pair of quadratic forms over R (not necessarily positively definite)? This is probably related to the Weierstrass elementary divisors (but it is not so easy to find information about them on the web). To be more precise, the case when A=diag(1,1,1,1,-1) and B is a symmetric 5x5 matrix is of interest.
Comment: This question gets asked periodically on MO.  The very first time was: http://mathoverflow.net/questions/1876 and the previous time was the comment by Willie Wong to this question: http://mathoverflow.net/questions/62244.  I refer to answers to those questions for suitable references.
Answer: Hi, I just read your question. I hope it's not too late to answer, but I think the following paper contains exactly what you are looking for:
R. C. Thompson: Pencils of complex and real symmetric and skew matrices, Linear Algebra and its Applications, Volume 147, March 1991, 323-371.
The author classifies - up to congruence - any pairs of real symmetric matrices, which amounts to give the classification for any pair of real quadratic forms.
You'll probably find of some interest also this paper of mine:
http://arxiv.org/abs/1106.4678
Answer: In a standard exposition (I.M. Gelfand, Lectures on Linear Algebra, or A. I. Maltsev, Foundations of Linear Algebra) it is required that one of the forms is positive definite, and this cannot be dropped. Some general results in terms of elementary divisors are given in Maltsev's book too. A little Google search gives also a reference to the paper
F. Uhlig. A canonical form for a pair of real symmetric matrices that generate a nonsingular pencil.  Linear Algebra Appl. 14, 189-209 (1976),
which may contain some generalizations.
Comment: The positive-definite condition can be dropped and does get dropped, say, when looking at possible types of Ricci tensors in lorentzian spacetimes.  See my answer to this question: http://mathoverflow.net/questions/1876/orbits-of-real-groups-canonical-forms-of-matrices/1891#1891  for a recent reference which does this.
Comment: I meant the condition cannot in general be dropped (Gelfand in his book gives a counter-example).


Why Direct Broadcast satellite is interrupted by climatic conditions?

Question: Television signals received through direct satellite service are mostly interrupted by the climatic conditions. But other communication systems that uses satellites are not that much affected. Why is this so ? Or is it just because television signals are hard real time?
Comment: Because the big boys have more than one satellite and more than one dish on more than one building.
Comment: Maybe you can give an example of a satellite system that isn't affected?
Comment: I suspect it's because you only have one dish on your house with no alternative routing. Most important communications links have at least one backup path.
Comment: @john Direct broadcast service use geostationary satellites right? So how is it possible to have alternative routing?
Answer: The difference is probably because of the different Radio Frequency Bands used by the different Satellite Services.
Normally the higher the frequency is, the more is affected by the rain. On RF links rain fade start to occur at some GHz and it becomes very important if you go above 10GHz.
You can check the ITU-R model for the rain attenuation on this link:
http://www.itu.int/rec/R-REC-P.838/en
Another thing that might make the difference is how fault tolerant the service is (they could have redundancy, diversity…).
Answer: If one had two antennas located a mile apart pointing at the same satellite, it's likely that during adverse meteorological conditions both antennas would have a significant fraction of data packets disrupted by weather, but the sets of disrupted packets observed by the two antennas would be different and largely unrelated.  Likewise if one had two adjacent antennas pointed at different satellites.  A typical DBS receiver setup, however, will just have one antenna receiving a signal from one satellite.
Further, some forms of satellite communication can use after-the-fact error recovery: a receiver that can tell that a packet got corrupted can request a retransmission.  The need for retransmission will increase latency, but can be made mostly transparent to the user.  By contrast, if a receiver can't capture a broadcast video packet when it's transmitted, there's no mechanism for it to find out what it missed.
Answer: Satellite reception degradation is determined by several factors. The lower the frequency the less affected by rain fading. C band less effected, Ku and Ka band more affected. The ground based receiver position in the satellites footprint. The further away from the maximum signal zone the greater the effect. The precision of the aiming of the antenna itself lessens the effects. Rain and snow absorption and refraction of the signal. The altitude of satellite above the horizon. Transmission mode and bandwidth would also be a consideration as well.


Center tap transformer

Question: How can I convert a 113B13 transformer to a center tap transformer? Is like this, for example:
- primary coil: 1 and 2 pins.
- secondary: 3 and 6, where 4 and/or 5 is the center tap?
Will this work?
Comment: Why would you need a center taped pulse transformer? Show a schematics of this particular use.
Comment: @MarkoBuršič For the "Royer inverter".
Answer: Connect pins 4 and 5 together, and it becomes the center tap. Between 1 and 2 would then be the primary.
Comment: @Arttu:  Do you understand what ratio the center-tapped transformer will have?
Comment: @OskarSkog I will use for "Royer inverter".  I have 113B13 which is 1:1:1 itself. By using 3-6(with 5 and 4 as center tap) as a primary and 1-2 as secondary it will become 2:1 step-down transformer. So, if I need a step up transformer I need to increase the number of turns on the secondary. That I think about it.
Comment: That's correct.   Just had to check that you weren't going to do something stupid.

Center tap transformer


"spread-to-maturity" as defined by Bloomberg

Question: Bloomberg has a number "spread to maturity" they display in some screens for fixed coupon bonds. Does anybody know the exact definition of this spread? I am not sure which screen it is but this spread is usually shown together with other, more well defined, spreads such as I-spread and Z-spread. Needless to say I don't have access to BBG. Thanks.
Comment: There is yield-to-maturity but I don't see spread-to-maturity. If you give the name of the screen where it can be found it will help.
Comment: I've been searching for the name of the screen I saw but I just cannot find it. The term is not on the current YAS screen, as far as I know, so I'm thinking maybe I was looking at a very old screenshot of a bbg printout.  I think the term makes sense for a FRN but for a fixed cpn bond it is too unspecific.
Answer: The "spread to maturity" is the bond's traditional yield-to-maturity (YTM) less the riskless/govvie yield at the same maturity.
Where this starts to get problematic is when (corporate) bonds have callable repayment structures. So most data providers also provide a "yield to worst" (ie YTW if called) measure as well as "yield to maturity". YTW <= YTM. The "spread to worst" is variously called "OAS", aka the Option-Adjusted Spread. This is the by-default measure (not a measure of default risk!) that credit markets look at.
So it could be (likely but not 100% sure) that the spread-to-maturity is YTM (not YTW) less govt, which could well be a crazy number if the bond is almost certainly going to be called by the borrower.
Then the "yield" and associated "spread" to maturity is a set of figures already predicated on that bond crashing so much that the borrower elects not to repay, and refinance on better terms.
Can you get YTW and OAS; and how do those look in comparison???
hope this helps,
DEM
Comment: Thanks Dem. I agree that if the bond has embedded options then I think OAS is the only relevant spread so I'm assuming plain fixed cpn bonds only. When you say that "Spread-to-maturity is ytm less govt-yield of same maturity" it sounds like it would be the same spread as the "I-spread" (linear interpolated on maturity) which is a another BBG-terminology-spread. One hypothesis I have is that "spread to maturity" refers to the spread between ytm and an implied ytm when all cashflows are priced from a govt zero curve (via bootstrap or other zero model).


Bounding the difference of numbers between 0 and 1 with the same power

Question: I would like to prove the following inequality (I guess it holds but I'm not able to formally do it).
Consider two numbers $x,y\in (0,1)$ and the positive real number $\alpha$. Then, can I write
$$|(1-x)^\alpha-(1-y)^\alpha|\leq c \cdot |x-y| $$
where $c$ is a constant depending on $\alpha$? Thank you!
Answer: Function $f$ defined by $f(x)=(1-x)^\alpha$ is continuously differentiable, therefore for all $x, y$ in $[0, 1]$,
$$|f(x)-f(y)|\leq  |x-y| \cdot \sup_{t\in[0,1]} |f^\prime(t)|$$
Since $f^\prime(t)=-\alpha(1-t)^{1-\alpha}$, the inequality you're seeking is true if $\alpha \geq 1$, with
$$\boxed{|(1-x)^\alpha-(1-y)^\alpha|\leq \alpha \cdot |x-y|}$$
Note that if $\alpha\in (0,1)$, the inequality is not true. For instance, take $\alpha=\frac 1 2$, and $x=1-h$, and $y=1-2h$:
$$\frac{|\sqrt{1 -x} -\sqrt{1-y}|}{|x-y|}=\frac{1}{\sqrt{1 -x} +\sqrt{1-y}}=\frac{1}{(1+\sqrt 2)\sqrt h}\rightarrow +\infty$$
Answer: Consider $x,y\in[0,1]$ and the function $f(x)=(1-x)^\alpha$. Then the inequality holds if $f$ is Lipschitz continuous. Because a derivable function is Lipshitz continuos (here an answer), if $\alpha\geq1$ $f$ is derivable and so the inequality holds.
But for $0<\alpha<1$, $f$ isn't continuously differentiable on $[0,1]$ (the derivative is $-\infty$ at $x=1$), but because $x,y \neq 1$, $f$ is derivable on $[0,\max(x,y)]$ and so the inequality holds only here ($c$ depends on $\max(x,y)$!).


Class 1 and 2 medical device recalls

Question: How can I structure a question on the FDA OpenApp that will return all Class 1 and 2 medical device recalls for radiation therapy devices over a certain period (e.g. the month of June 2014)?
Answer: The short answer is as follows (here is a clickable link though) which searches for recalls initiated during June 2012, that were classified as Class I or Class II, and had the word "radiation" somewhere in the recall documentation.
https://api.fda.gov/device/enforcement.json?search=radiation+AND+classification:("Class+I"+OR+"Class+II")+AND+recall_initiation_date:[2012-06-01+TO+2012-06-30]&limit=100
There are a number of caveats to keep in mind though:

This query relies on "radiation" being included in one or more of the fields listed at https://open.fda.gov/device/enforcement/reference/ such as product_description but there is absolutely no guarantee radiation drugs will mention that keyword.
This query also relies on recall_initiation_date be present which appears to only be there for 59% of all the device enforcement reports available in the API (4639 of the 7855). Note that field report_date seems to have 100% coverage. Maybe the recall_initiation_date field is only available after a certain date? More digging needs to be done to make that call.

Class 1 and 2 medical device recalls


What are the mitzvos that are not forever?

Question: This Shabbos, someone noted that the Sefer Hachinuch says that there are no mitzvos at all in this parsha (Bamidbar). I responded at once, That's absurd. It seems like it contains dozens of mitzvos!
Of course, what they meant is that there are no mitzvos l'doros, for all generations - one of the requirements that the Rambam lists in his Sefer Hamitzvos (Shoresh 3). So all the commandments to count the nation, to set up degalim, to redeem the Levi'im, how to cover all the vessels when they move... None of those are part of the תרי"ג mitzvos.
So I am wondering:
a) Has anyone ever worked out a list of all these "temporary" mitzvos in the Torah? Don't eat the fruit of that tree; Avraham, lech lecha; Yitzchak, don't leave Eretz Yisroel; Yaakov, take your family and flocks and return; Moshe, don't go too close to the bush...; Eat the Korbon Pesach with your loins girded, staff in your hand... How many are there?
b) If no one has bothered, why not? Are they less important than the 613 mitzvos? - I spent a couple of years studying Zevachim, even though we can't do it (yet), and even though many great people who studied it died without ever seeing the Beis Hamikdash. Maybe I should also study how to stay away from Har Sinai, because we did it once? Is it so clear that there is a difference between our past and our future?
c) Nothing can be part of the Torah except what Moshe Rabbeinu taught us; afterwards, לא בשמים היא. What about one-time mitzvos? Is Hashem's commandment thru a navi (Go, speak to Achav. Your child will be a nazir from the womb.) any less a mitzvah than Hashem's one-time commands to Moshe, just because it cannot become part of the Chumash? Should those be counted too, if someone counts them?
Update: judging by some comments, I should explain (c): For sure any command by a navi is completely obligatory. I meant a different question: Is there a special category of temporary commands by a navi that are fundamentally different because they were actually given as mitzvos of the Torah. For instance, the laws of degalim were followed for forty years; the laws of wrapping the keilim when the mishkan moved were presumably followed for hundreds of years, up until the final move into the Beis Hamikdash. Same with all the laws of how to deal with heter bamos - all skipped by the Rambam. But when they learned Shulchan Aruch, that was part of what they learned, all that time. These seem to be part of Toras Moshe. That seems different to me from the one-time commands to Eliyahu - or for that matter even the one-time commands to Avraham Avinu which are quoted in the Torah but don't translate into a command to Israel. Or not.
Comment: Comments are not for extended discussion; this conversation has been [moved to chat](https://chat.stackexchange.com/rooms/108476/discussion-on-question-by-michoelr-what-are-the-mitzvos-that-are-not-forever).
Answer: I asked R' Tzvi Berkowitz shlit"a for his take. Here was his response [email]: "We study the mitzvos that we have even if we can't do them right now. The mitzva that Moshe Rabeinu was given to not come close to the bush was never given to us. The mitzva that the dor hamidbar had during the midbar was never given to us."
"never given to us". That's a really interesting way to describe it.
Comment: I don't see how this answers your question. Probably because it's not clear to me what your question was in the first place.
Comment: "I was never given the command to bless the people daily." You were. It was given to the nation in perpetuity, which includes you.
Comment: I was never given the command to bless the people daily. Shall I study it?


Cycle class of zeroes of a global section

Question: Let $\mathcal{F}$ be a locally free sheaf of rank $n$ on an $n$ dimensional complex manifold $X$. If the zero locus of a generic global section of $\mathcal{F}$ is $0$ dimensional, then its cycle class is equal to $c_n(\mathcal{F})$. What can be said if the generic section has a zero locus of positive dimension?
Answer: Let $V = H^0(X,\mathcal{F})$ be the space of global sections of $\mathcal{F}$ and let
$$
V \otimes \mathcal{O}_X \to \mathcal{F}
$$
be the evaluation morphism. If it is surjective (i.e., $\mathcal{F}$ is globally generated), then the zero locus of a general section is zero-dimensional, and has class $c_n(\mathcal{F})$.
So, assume that the evaluation map is not surjective. Assume, moreover, it has a constant rank, so that its image $\mathcal{F}' \subset \mathcal{F}$ is a vector subbundle of rank $r$. Then any global section of $\mathcal{F}$ comes from a global section of a globally generated vector bundle $\mathcal{F}'$, and their zero loci coincide. Therefore, the class of the zero locus of a general section of $\mathcal{F}$ is equal to $c_r(\mathcal{F}')$.
When the rank of the evaluation morphism is non-constant, the class of a general zero locus is not so easy to find. To sketch a possible approach, one can first blowup $X$ in such a way that the rank is constant on the blowup, and then pushforward $c_r(\mathcal{F}')$ with respect to this map.
Answer: Assume the zero locus has positive dimension, but is smooth (or is, at least, locally complete intersection). Then it comes with a vector bundle (so-called "excess intersection" bundle), whose top Chern class equals $c_n(\mathcal{F})$.
For instance, if the original section is just zero, its zero locus is the whole $X$, and the excess intersection bundle is $\mathcal{F}$.
Comment: Thanks for your answer. I was hoping there is a way to find the cycle of the zero locus using some chern class. Is this possible?
Comment: What do you mean? There are many possibilities (one of them is $X$ itself). For instance, imagine that your vector bundle is a sum of line bundles. Then you can take several components of your section to be zero, and the other components general. In this way you will get a general complete intersection of intermediate multidegree as the zero locus.
Comment: I was hoping that for generic choices the cycle is well-defined, is this not the case?
Comment: @user2520938: Sorry, I misread your question. See below another answer.


Recommended machine learning algorithms for a 10-class image classification problem with only 1900 samples

Question: I am trying to determine the right approach to take for an image classification problem which involves 10 classes and only 1900 samples. The images (1288 x 964 resolution) are of industrial parts whereby each class of part differs by its serial number as well as other features. I've considered using a CNN but am wondering if this may be infeasible due to insufficient quantity of data; or is this not the case? Otherwise from my research I've determined that the more traditional KNN or SVM may work better due to less data but am in need of some expert guidance. Thank you.
Comment: Try transfer learning on a CNN that is pretrained on ImageNet or similar. At 190 samples per class it might do allright
Comment: +1 for transfer learning. Suitable data augmentation will also help. In practice,  the more one can standardize how the photos are taken (i.e. if this is e.g. sorting parts,  then ensuring consistent lightning etc. Likely helps).
Answer: While it depends on the data you have and the distribution of it over the classes, it sounds that you can use a pre-trained model that was trained on a large dataset (preferably somehow similar to yours).
As it was mentioned by @johnor you can use one transfer learning technique for example to 'Freeze' all parts of the model and train only the last fully connected layer with your new classes.
The idea behind it, is that the pre-trained model have learned good representations of an image, and therefore it can be used to represent any new image.
Depends on the language and library you chose to use, you can find several good pre-trained models on the web (for example ResNet that was trained on ImageNet)
Basically the idea is to use the pre-trained model to attain a vector representation of the image, we can refer to it as the encoder of the image.
And then, train only the decoder to classify the encoded vector to classify it to the relevant class.
There are several more techniques that can be used, you can read more about it in this article:
https://towardsdatascience.com/a-comprehensive-hands-on-guide-to-transfer-learning-with-real-world-applications-in-deep-learning-212bf3b2f27a
As I've mentioned in the beginning of my answer, it depends on the data you have.
It might be that for your specific data a more classic ML algorithm (such as RandomForest) can give sufficient results


Advantages or disadvantages of submitting to the new APS open access PRResearch journal?

Question: In the decision about where to submit a physics manuscript, which are the advantages or disadvantages of the new open access PRResearch as a better choice over PRA/B/C/D/E?
PRResearch is rather new and does not have an impact factor yet. Do you expect the impact factor would be comparable to the other PRA/B/C/D/E journals, or slightly higher/lower?
Apart from the impact factor, do you see any inherent advantage to publish in a full open access journal? Notice that also the other PR* journals have open access options.
Also, the fact that the journal is multidisciplinary (as PRL and PRX) can be an advantage or disadvantage?
Are there any other aspects to consider?
From the APS website https://journals.aps.org/prresearch/welcome:

The acceptance criteria for PRResearch are aligned with those of other long-established journals in the family, such as Physical Review A, B, C, D, and E.
Comment: Prior to the journal opened up for submissions, I asked a few editors of other APS journals about the need for full access when e.g. PRA/PRB have open access options. Apparently there are some funding options (e.g. institutional funding for publication charges) that apply only to full open access journals, not hybrid options. So part of APS' goals with PRResearch was to provide an option for authors under such restrictions.
Comment: Certainly, it does not seem too different from e.g. https://academia.stackexchange.com/questions/76420/is-the-nature-publishing-groups-scientific-reports-journal-well-regarded
Comment: @sintetico: *I am […] asking for […] advantages/disadvantages of submitting to a specific journal.* – which is pretty much the definition of a [shopping question](https://academia.meta.stackexchange.com/q/3657/7734). (If this was not among the guidance you were shown, please tell me as this sounds like a bug that should be fixed.) A question that you can ask here is what the potential motivations for this new journal could be (in particular since PRA–PRE already have open-access options). If you wish to do so, please ask it as a fresh question (since the current answer doesn't match it).
Comment: I suppose one question to ask yourself is whether your paper fits well within one of the subcategories delineated by the A-E journals. If it does, that might be the best way to reach your audience. But if it is interdisciplinary or doesn't have an obvious home in one of them, PRR might get you seen by more relevant people.
Comment: @Wrzlprmft This is really a splitting hair argument, "advantages/disadvantages" vs "potential motivations", is it really a matter of rephrasing the question, nothing more, do you agree with this? Also, as I and other members mentions, there are already questions which are very similar to my question and which are not closed...
Comment: I really do not understand why the question was closed. I am not asking for a  personal advice, but about advantages/disadvantages of submitting to a specific journal. There are also similar questions about other journals.
Comment: @user151413 Yes, exactly!
Comment: @Anyon Good point, proabably some funding bodies only pay for open access fees when they are mandatory.
Comment: @Wrzlprmft That would indeed be a good question!  (And there already some good comments in that regard.)
Comment: You might also ask very general questions about publishing in a pay-to-publish journal vs. a pay-to-view one or one with a broad vs. a narrow scope (in each cases assuming all other things being equal and not naming any particular journals).
Comment: @sintetico: *is it really a matter of rephrasing the question, nothing more, do you agree with this?* No, but I see that my phrasing was not particularly clear. To clarify, I am talking about motivations for the APS to issue the journal, not for motivations for authors to choose it. — *there are already questions which are very similar to my question* – when in doubt, please always consider the current guidelines, not precedents. There are some old questions which should have been closed but weren't. (I now closed the question in question.)
Comment: @Wrzlprmft Perhaps your rephrasing is still not clear...Why anyone on this website or in academia in general would care about the motivations for APS to issue the journal? Instead academics are concerned about the publishing process. In other words, the point of view of academia is to publish in a journal, not to issue a journal.
Comment: @Wrzlprmft I will be glad to rephrase this question, if I have a clear guidance. But I haven't got any meaningful guidance yet.
Comment: @Wrzlprmft Also, the question is closed because "off-topic", not because it is a shopping question. Clearly, it is not off-topic, nor a "shopping question".
Comment: @sintetico: I indeed suggested that you ask about the (potential) motivations of the APS, for example: "What motivations could the APS have to issue the journal PRResearch in light of its current portfolio?" Understanding the motivations is interesting to understand journal politics and can help to understand what the point of the new journal is and in particular why they expect people to choose the journal.
Comment: *the question is closed because "off-topic", not because it is a shopping question.* – Can you please show me a screenshot of what exactly you are seeing (it's different for you than for me), so we might improve this?
Answer: This is impossible to say: As you note yourself, it is a new journal, and no-one knows where it will end up ranking.
On the other hand, my sentiment would be that it goes in the PR[A-E] bin, rather the PRL/X one (in line with the quote you give).  Now since there are five PR[A-E] jounrals, and only one PRR, I would assume that it has good chances to rank higher than PR[A-E]. However, it could also go the other way: Given that you can publish for free in PR[A-E], while PRR is rather expensive, it could be that they only get a very limited number of submissions and cannot reach such a level.  (The initial waiver for publication fees certainly suggests that they want to avoid such an effect until the journal has established itself at a corresponding level.)
Comment: @Anyon My point is rather that people w/out open access funding will not be able to submit to PRR, which will have some effect on the quality (or, at least, it will form a filter layer).
Comment: @sintetico You can apply different types of logic here.  Either less submissions -> less good submissions -> less good publications, but there are probably also some arguments supporting your reasoning.  (Though, well, again: What matters is the best papers submitted there, until the cutoff where they accept it, not the average quality.)
Comment: If they get a very limited number of submissions, would this automatically boost the impact factor? One can argue that researchers with more funding are also producing better papers in average, thus the expensive fee will act as a filter, by allowing few publications, with an average better impact/citations?


What software / methods to learn for nanophotonics (a branch of photonics) applications?

Question: I'm new to nanophotonics and been looking for some software and methods (Design, modelling, simulation .etc) used in this scientific field. I'll be grateful to know some.
Answer: I have seen most people using CST or COMSOL. I, personally, have more experience with the latter. MEEP has also been used, but it is more of a code library than UI-software.
Nanophotonics is old antenna theory+a bit of atomic optics+waveguides+nanofab. I would advise to also brush up on waveguides and free-space radiation, i.e. antennas (only basics). Atomic optics may come in handy, but only if you start hybridising with quantum dots etc.
Nonlinear optics, again basics, can also be useful. e.g. given a metamaterial with symmetry of a rectangle (D1), can you explain whether it will exhibit quadratic nonlinear response? What about hexagon (D6) or triangle (D3)?
A lot depends on whether you are more interested in integrated optics, i.e. waveguides, or free-space optics, e.g. metamaterials
Comment: Thanks for answering.
Comment: @user668687, no worries. Good luck. BTW, some people also used Lumerical, though this is more for the integrated than free-space optics, but works in free-space as well. FDTD has some peculiarities though, mostly to do with meshing and (temporally) dispersive response


Is there any canon between Season 1 of "Andor" and "Rogue One"?

Question: Just finished season 1 of Andor. Absolutely loved it and want to know if there are any books or media that tells what will happen to Cassian between now and Rogue One.
Comment: Season 1 ends on 23 Nov 2022.  12 eps in total.
Comment: This seems perfectly on-topic to me. There's at least one (and possibly more) canon works that deal with Andor's antics prior to Rogue One
Comment: Given that there's already been a second season confirmed, for which any other version of the story would be either non-canon or a massive spoiler, I think it's safe to assume the answer is "not yet". That puts it firmly into the "future works" category, which I believe is considered off-topic here.
Comment: Technically yes - https://starwars.fandom.com/wiki/Rogue_One_-_Cassian_%26_K-2SO_Special_1 - but agreed that this seems mainly a future works question.
Comment: @Valorum - would this not be considered a list/recommendation question?
Comment: @fez - Limited lists are fine. There can't possibly be more than a couple of examples. Now, if OP had said stories containing Luke between ESB and TFA, that would be unsustainable
Answer: So far there are relatively few non-Andor appearances of Cassian Andor in material taking place before Rogue One.
Cassian & K-2SO Special (2—0 BBY)

Rogue One - Cassian & K-2SO Special 1 is a standalone comic issue taking place between 2 and 0 BBY, and shows how Cassian and K-2SO met. It came out in August 2017 and takes place after the founding of the Rebel Alliance, which happened in 2 BBY.
Secrets of the Empire (2—0 BBY)

Secrets of the Empire is a "VR experience" formerly available at The Void locations. The players are given a mission by Cassian to infiltrate Darth Vader's castle on Mustafar. Cassian introduces himself as "Captain Cassian Andor of Rebel Intelligence", indicating that it takes place after the founding of the Rebel Alliance in 2 BBY. It came out in December 2017.
The Mighty Chewbacca in the Forest of Fear! (0 BBY)
Cassian also appears in the junior novel The Mighty Chewbacca in the Forest of Fear! I haven't read this one, but Google Books substantiates Wookieepedia's claim that Cassian makes an appearance:

"Captain Andor, why is it important?"
"That's classified information, and these are the Emperor's errand boys," said Cassian. "I think I'll keep that to myself."
 Source: Google Books preview of The Mighty Chewbacca in the Forest of Fear!


Are there wood sealers that are safe for fresh or saltwater marine use?

Question: I have a wood dock over a lake.  It is time to clean and seal the dock.  I am planning on pressure washing the dock first, then I am planning to have a clear seal.  Looking at products in Lowe's and Depot I can't determine what is safe to use. I don't want it to look like a BP spill or kill any life forms.
Comment: @Tester: Going for that Copy Editor badge? :)
Comment: Are we talking "deck" or "dock" here?
Comment: @Doresoom: Just trying to clean up the "Thanks" at the end of questions. I just couldn't take it anymore!!! Wish they would write a script to get rid of it, like they did to remove the salutations at the beginning of questions.
Comment: @Tester: Feel free to be OCD (I've been know to have such tendencies from time to time myself). I'm just giving you a hard time.
Comment: @Carl technically a dock.  It's built just like a deck and when I posted the question it was the closest tag.  I didn't have the rep to add a tag.
Answer: They do make stain specifically for marine use.  Doesn't say specifically that it's environmentally friendly, but the MSDS sheet does say it's water soluble.  The same manufacturer has environmentally friendly stains as well, but I have no idea how well they might work (or exactly what "environmentally friendly" means to them).


Electrical isolation in PLC output cards

Question: Every output card spec sheet I read says something about electrical isolation. One I read recently said "Isolated 1500VDC channel to channel". What does isolation mean and what advantages do isolated output channels have over non-isolated channels?
Comment: Each output channel is an independent circuit. There's no common ground between them, and neither they have any connection to the power supply of the PLC. You can easily use them as a part of an external circuit without having to think about those things.
Comment: Related: [PLC I/O module specs](https://electronics.stackexchange.com/questions/337621/wago-plc-datasheet-i-o-module-specs/337632#337632).
Answer: Isolated means each DC input has its own + and - connection that is electrically separate from the other inputs. To make it clear, see below wiring diagrams of 2 DC input cards for AutomationDirect Productivity3000 Controller.

The above is a 8-point discrete input module, 12-24VDC sinking/sourcing, 8 isolated commons, 1 point per common. This means each channel is its own circuit. Since this is a 12-24VDC card, Channel 1 can be connected to a 24V power source, channel 2 can be connected to a 12V power source, etc. As long as this card sees 12V and above, it's a 1. Now compare with the one below

Above is a 16-point discrete input module, 12-24VDC sinking/sourcing, 4 isolated commons, 4 point per common. That means there are for group of inputs. The groups are separated(isolated) from each other but within a group the inputs are not isolated. This means if you have two inputs, you can connect them to channel 1 and channel 2 as long as they share the same power source. If they are powered from different sources, you must connect them to inputs in different groups such as channel 1 and channel 5. Now suppose channel one is connected to an input with 12VDC but everything else you have is powered by 24VDC. That means channels 2,3, and 4 are wasted since you can't mix voltages per group. You may ask, what would happen if you mix voltage sources in the non-isolated channels? If the commons are all grounded, then probably they may be fine. However most DC supplies are ungrounded or cannot be grounded so you end up with sources at different potentials tied together and you will end up with interference.
So as you can see, isolated channels require 2 terminals per input so a card has a limited number of channels and tends to be more expensive than a non isolated with the same number of channels but gives you more flexibility in your wiring.
Answer: Functionally though, having isolated I/O means that if something goes horribly wrong in the field with your I/O wiring and wires get crossed up, you might damage that particular I/O point, but it will not go further into the PLC and fry the whole thing. it's easy to replace one I/O card, it's not easy to replace an entire PLC.


Have a question about training routine

Question: I am 17 years old 180cm and i weight 70kg and I train 6 days a week, around 1 hour per day and my routine is pretty much like this monday-legs abs and biceps, tuesday -chest, tricep and bicep, wednesday- shoulders, Jack and bíceps, i then just repeat that plano the resto of the week AM i doin it right?
Comment: Can you provide a bit more details about your routine ? Meaning reps, sets etc... Depending on how much and what exercises you do the answer will vary. Also what are your goals ? For how long have you been training ? Are you satisfied with the results ?
Comment: Hey, for every exercise i do 3 sets of 15 reps, everyday for bíceps i train with dumbells with 10kg on each si de and do around 9-12 sets of 3-4 different exercises but Mainly bicep curls and hammer curls, for chest i use the PEC deck machine with around 42 kg and Raising it after every rep , il use cable fly aswell and then dumbells in the press bench, for back i also use the pec deck machine , Bent o ver barbel deadlift and wide gripe pulo ups and for shoulders i do los pulley raise, alternate front raise and barbell front raise all of that with the weight i can handle for the 15 reps
Comment: Aldo i have been takin milk protein shake  after every workout, i would love to know if im taking it right and some people told me that i shouldnt train everyday the same muscle (bicep). And to answer if im seeing any results, i havê gained 5 kg in 3 months but i just started this routine 2 weeks ago, after that i would just go everyday and just do what i felt Luke training
Answer: Thank you for adding more info in the comments.
I wouldn't say your routine is bad, but here are a few things to remember when designing a workout routine:
I Progressive overload
As a beginner, you need very little stimulus to progress. You can do 2 sets of 12 reps 3 times a week and see massive results.
The volume (weight * sets * reps) that you do for each body part seems very high for a beginner.
The problem is this: There is a point where your body gets used to the training stimulus and will need more to progress.
Let's say you start by doing 2 sets of 12 reps 3 times a week. After a few weeks/months, you won't see as much results. To trigger more reaction, all you need to do is start doing 3 or 4 sets of 12 reps 3 times a week. It is still reasonable. Then after a few weeks add a seconds exercise for example. Then more reps/weight/sets. Build up the volume over the years to keep progressing and counter the ability of your body to adapt.
However if you start straight away like you did by doing quite a lot of volume, you won't have much room left for increased stimulus. Doing 9-12 sets total for each body part is a lot. When you hit a plateau, you'll have to go up to 15 or even 20 sets. Maybe play on frequency too.
Here is an interesting study on progressive overload
II Muscle protein synthesis
Training your biceps every day is not an issue itself. Biceps are fairly small muscles and recover fast. However you don't get the full benefit of muscle protein synthesis response after a workout. It lasts for 48 hours.
You could try training them every other day instead and let them fully rest before hitting them again. See if it works for you.
You can read about it here
III What I would do
Just to add up on this and be more precise. Here is what I would do, assuming that your goal is aesthetics:
Train 3 times a week. Full-body routine. Starting with the main lifts (Squat, bench, deadlift) for 3 sets of 5-8. Adding 2.5/5 pounds every time or change for a variation of the main lift.
Then move on to accessory movements. One for each body part. 3 sets of 8-12. Add weight if possible every time/change the exercise.
Full example

Back Squat: 3 sets of 5
Bench Press: 3 sets of 5
Deadlift: 2 sets of 5
OHP: 3 sets of 8
Bent-over Rows: 3 sets of 8
Triceps extensions: 2 sets of 12
Bicep curl: 3 sets of 12
Upright Rows: 2 sets of 12
Leg Raises: 2 sets of 12
Calves Raises: 2 sets of 20

Then go home, eat well, sleep well, avoid stress, drugs. Repeat.
This is just an example, feel free to add/change to whatever you like the best.
I hope this helps !
EDIT
Just to clarify about your routine. I think it is good, but a bit too advanced for someone who can still gain 5 kg in 3 months. Start with less, build over time and it will pay off more in the long run.

Have a question about training routine


What is World Of Shadows?

Question: I have recently become aware of a world similar to world of darkness called world of shadows but all the wiki tells me regarding that world is that it is a parody of world of darkness. I scoured the internet for places where the books that describe world of shadows but i had no luck. In any case my question is that is world of shadows just a parody with no actual books or is it a setting with it's book removed from sale?
Comment: Got a source for the parody of WoD interpretation? I can find plenty of things called "World of Shadows," but no trace of that idea.
Comment: @JohnDallman I've linked to another rpg.stackexchange question that addresses it.
Answer: The "World of Shadow" is the game line produced by Black Dog Game Factory, the parody game company run by Pentex in Werewolf: the Apocalypse. It's detailed in Book of the Wyrm and Subsidiaries. There are no real books affiliated with it; it's an in-game entity.

What is World Of Shadows?


Creating a model for prices including supply

Question: I'm working on modeling secondary market ticket prices for sporting events, but the issue I'm running into is that the model (a linear regression) assumes that more season ticket holders and more tickets on places like StubHub mean that the game is more desirable, and thus the tickets should be worth more. The problem is that one year has a significantly higher number of both due to increased team performance, so it thinks prices should be going up when the increased supply of tickets on the secondary market is actually driving prices down. Is there anything I can do to address this problem?
Comment: What's your regression equation? Are you just using OLS for this one team?
Comment: My model currently includes games out of first place, the season tickets for the game, webpage visitors, the month, the high temperature, the number of stubhub tickets, and the average face value of the tickets listed on stubhub. And yes, it's OLS for one team.
Comment: Hey, just to get some feedback: did you look into the links I provided together with the answer? Was this helpful to you?
Comment: Yeah I did, and it sent me looking for a lot of other stuff that I didn't know about, so it was pretty helpful. I ended up figuring out my problem (which just involved messing with my factors some), but this was still informative.
Comment: That's good to hear. If you were satisfied with the answer you might consider accepting it which you can do by clicking on the check mark underneath the up vote/down vote button. Thanks!
Answer: To account for this outlier year you could include a dummy variable which equals 1 for this particular year and 0 for all others, like
$$p_t = \alpha + X'_t \beta + \gamma d_j + \delta q_t + \epsilon_t$$
where $d_j$ is the dummy for the outlier year $j$, $X_t$ include observable characteristics of the team and other explanatory variables, and $q_t$ is the supply of tickets.
If the effect of the team performance lasted longer than just this one year, for instance if the team moved into a better league, then the dummy $d_j$ should equal 1 for all the years after the team moved to the better league. It's best to plot the time series of the ticket prices to see whether you have a regime shift (i.e. ticket prices went up temporarily or permanently because of the league change) or just a change in the slope (i.e. a structural break).
As a side note: I'm sure you're already considering this but given that it wasn't mentioned in the question I quickly wanted to touch on it to make sure. Both prices and quantity supplied are outcomes of an equilibrium relationship between supply and demand. This means they are simultaneously determined. Therefore you could re-write the above regression equation as
$$q_t = a + X'_t\pi + \rho d_j + \theta p_t + \nu_t$$
which results in what is called simultaneity bias (slide 8).


What does a client side javascript templating framework offer?

Question: What is the use of frameworks like PURE or jQote etc. I can do dynamic things in plain javascript or JQuery using AJAX calls or an advanced library like DWR.
What new stuff do these templating frameworks bring to the table? I need to know since I have been asked to use a browser side templating framework without being explained why :(
Answer: I guess it depends on what you're using as your server code; it could be that the recommendation came from someone who hasn't heard about N/Velocity for example.
I think the main reason for client templating is that it removes the weight of transformation from the web-server.
It might also allow you to send your JSON from a dedicated box, and serve the template and client code from a different box.
To my mind, both of these 'bonuses' override the fact, that you're putting Data into the DOM that shouldn't be there. Firstly you'll have the JSON that is parsed by the template generator and then you'll have the HTML that is created.
Sure, viewing page source will look neat, but in terms of memory consumption for the browser it's bad,  especially if you're in the UK and have Government contracts who mandate IE6 support.


LWC component which fetches data via apex not visible when site published

Question: So there's a News reminder Component in my website and from Apex class method the records from Member object are fetched and displayed on cards.
The functionality works fine in LWC Builder but when i publish the site, the component is not visible, at console there is an error logged for status 400 which is -> {"error":[{"message":"You do not have access to the Apex class named 'ProfileController'."}]}
here ProfileController is my apex class name.
What actions need to be performed to resolve this ?
Comment: Can this help you? https://salesforce.stackexchange.com/questions/301645/you-do-not-have-access-to-the-apex-class-named-cannot-find-the-cause
Answer: You'll need to make sure that the User has access to the Apex Class. Here's the Salesforce documentation on adding Apex Class Access to Permission Sets:
https://help.salesforce.com/s/articleView?id=sf.perm_sets_setting_apex_access.htm&type=5
You'll then need to ensure the Permission Set is assigned to the User:
https://help.salesforce.com/s/articleView?id=sf.perm_sets_assigning.htm&type=5
You can also add the Apex Class Access directly to the User's Profile, if you prefer.
EDIT:
Actually, it sounds like you might be trying to add this permission to the guest user profile of an Experience Cloud site, which can be more difficult to find. Here's the documentation on navigating to the guest user profile of your site:
https://help.salesforce.com/s/articleView?id=sf.rss_config_guest_user_profile.htm&type=5
Once there, the directions are similar to adding the permission to a Permission Set. Find "Apex Class Access" and add the desired class to the available classes.
Answer: To set the public access settings for your site:

From Setup, enter Sites in the Quick Find box, then select Sites.
Click the name of the site you want to control.
Click Public Access Settings to open the Profile page for your site profile.

This page includes all the functionality for viewing and editing profile
permissions and settings, but you can't clone or delete the profile.
In the site profile, you can:

Enable Apex controllers and methods for your site. Controllers and methods that are already associated with your site's Visualforce pages are enabled by default.
Control the visibility of custom apps. If you want to expose a custom app and its associated tabs to public users, make only that app visible and make it the default to avoid exposing other pages. If any of your site pages use standard Salesforce headers, other visible applications may be seen by public users.
Set the login hours during which users can access the site.
Restrict the IP address ranges from which you can access the site.
Note
Set the object permissions for your site. You can grant "Read" and "Create" permissions on all standard objects except products, price books, and ideas; and "Read," "Create," "Edit," and "Delete" on all custom objects. All permissions that aren't set by default must be set manually.
Warning

Refer to this documentation: https://help.salesforce.com/s/articleView?id=sf.sites_public_access_settings.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.community_designer_create_record_list.htm&type=5