Uncounted ballots after someone reaches 270 electoral votes. What happens?

Question: In this time of "all votes count", what happens to uncounted ballots if one person gets 270 electoral votes? So do all votes really count? Isn't the race over at that point?
Comment: Its the same as in every other country in the world: Until the official results have been announced, nobody "got" or "won" anything.
Comment: In virtually all jurisdictions there are other races on the ballot -- senators and congressmen, state legislators, state judges, local officials, etc.  They need to be counted even after the presidential contest has been decided.
Comment: I cannot think of any other country who has an electoral college .or a specific number a candidate must reach to win so we are not like every other country.
Answer: No one actually gets 270 Electoral votes until the Electors vote in their States on December 14th. When a State or Election gets "called", that's not an official thing: it's a judgement by the news networks that, based on the officially released vote counts and other evidence (like exit polls), that candidate is almost certainly going to win that state. It doesn't have any official meaning, though.
So, even if the election is called for a candidate and the other candidate concedes, the ballot counting will continue in each state until the final count is certified by that State, allowing it to file Certificates of Ascertainment and select electors to vote in the electoral college.
You can read the gritty details of the process here: https://crsreports.congress.gov/product/pdf/IF/IF11641
Comment: Also, the presidential race is not the only race on the ballots in question. Every seat in the House is up, a third of the Senate, and many local races. Those elections count, too.
Answer: Officially speaking no one will get any electoral votes in this election until December 14th 2020:

Electoral College electors in each state don't vote until Dec. 14. The electors' votes typically align with the popular vote in each state. But not all states require the votes cast by electors to mirror the popular vote. Certificates recording the electoral vote results in each state must be received by the president of the Senate and the archivist no later than Dec. 23.
The official results of the electoral votes are sent to the new elected Congress, which is set to meet in a joint session on Jan. 6, 2021, and announce the results.

So on paper the next President will not be known until December 14th at the earliest and not confirmed until January 6th. This leaves plenty of time for states to tally up their votes and do a recount if necessary. Remember that announcing the winner on election night is a relatively recent tradition, made possible by light-speed communication. No such technology was available at the time when the Constitution was adopted and thus there's a lot of time available between the election and the official results being certified.
Answer: That someone reaches 270 electoral votes doesn't mean that the candidate won as it's only about the popular vote at the current moment, which isn't most important as people vote indirectly for president for electors who will vote for the next president. So all that is said at the moment is all about popular votes.

The Electors have to vote on December 14th for the next president

December 14, 2020: Electors Vote in Their States
Monday after the second Wednesday in December of
presidential election years is set (3 U.S.C. §7) as the date on
which the electors meet and vote. In 2020, the meeting is on
December 14. Electoral college delegations meet separately
in their respective states and the District of Columbia at
places designated by their state legislature. The electors
vote by paper ballot, casting one ballot for President and
one for Vice President. The electors count the results and
then sign six certificates, each of which contains two lists,
one of which includes the electoral votes for the President,
the other, electoral votes for the Vice President, each of
which includes the names of persons receiving votes and
the number of votes cast for them. These are known as
Certificates of the Vote, which the electors are required to
sign. They then pair the six Certificates of Ascertainment
provided by the state governors with the Certificates of the
Vote, and sign, seal, and certify them (3 U.S.C. §§8-10).
The six certificates are then distributed by registered mail
as follows: (1) one certificate to the President of the U.S.
Senate (the Vice President); (2) two certificates to the
secretary of state (or equivalent officer) of the state in
which the electors met; (3) two certificates to the Archivist;
and (4) one certificate to the judge of the U.S. district court
of the district in which the electors met (3 U.S.C. §11).

On January 6, 2021, the electoral votes will be officially started and it'll be known who won the election. If both candidates have the same electoral votes (269-269), the House of Representatives must enter in!

Executive Branch of US Constitution:

The
Person having the greatest Number of Votes shall be the
President, if such Number be a Majority of the whole
Number of Electors appointed; and if there be more than
one who have such Majority, and have an equal Number of
Votes, then the House of Representatives shall immediately
chuse by Ballot one of them for President; and if no Person
have a Majority, then from the fi ve highest on the List
the said House shall in like Manner chuse the President.
But in chusing the President, the Votes shall be taken by
States, the Representation from each State having one Vote;
A quorum for this Purpose shall consist of a Member or
Members from two thirds of the States, and a Majority of
all the States shall be necessary to a Choice.

-> January 6, 2021: Joint Session of Congress to Count
Electoral Votes and Declare Election Results Meets
On January 6, or another date set by law, the Senate and
House of Representatives assemble at 1:00 p.m. in a joint
session at the Capitol, in the House chamber, to count the
electoral votes and declare the results (3 U.S.C. §15).
https://crsreports.congress.gov/product/pdf/IF/IF11641

January 20, 2021: Presidential Inauguration
On this date, the President and Vice President are to be
inaugurated. The Twentieth Amendment set the date for
inaugurations as January 20, beginning in 1937. Since
1981, the ceremony has, with one exception, been held on
the West Front of the Capitol. The Vice President takes the
oath first, followed at noon by the President.


Invalid SharePoint Online list 'Documents' (ErrorCode: 0x0201000D) with Migration Tool csv

Question: When using Sharepoint Migration Tool on a language other than English to copy files to the default "Shared Documents" (or "Documents" as you are to use), it gives  Invalid SharePoint Online list 'Documents' (ErrorCode: 0x0201000D).
Whats the correct Document Library name to use?
Answer: It seems a Language issue. Make sure that the language settings of the user used in SharePoint is set to the same language as the original site creation default language.
Or use the same language that SharePoint Migration Tool used for library name.
Comment: SharePoint Migration Tool is only in English. However, when selecting "File Share" rather than CSV, it correctly discovers the Library name, (In my case, in Japanese). All Other libraries created in another Language are created as "DocLibx". This issue is only for the default "Documents"  Library. MS Details seems wrong.


Coding union-find in 4-connectivity two-pass algorithm

Question: I try to code in c++ a component labelling code uses two pass algorithm with 4-connectivity. You might want to see https://en.wikipedia.org/wiki/Connected-component_labeling. In that algorithm there is a data structure named as union-find. I cannot get the structure of that and cannot code it since I cannot understand how the algorithm is using that structure.
Do you know how to use union-find in that algorithm or at least Is there any native library in C++ environment or do you know any source to understand that structure. Maybe an animation might be useful.
Comment: This can be found at http://stackoverflow.com/questions/14347065/2d-array-neighboring-algorithm/14350691#14350691
Answer: The data structure of Union-Find is also called a "disjoint-set". You can actually find some more descriptions and information of disjoint-set on its Wikipedia page (http://en.wikipedia.org/wiki/Disjoint-set_data_structure). A more detailed introduction to disjoint-set data structures call be found in the book "Introduction to Algorithms" Chapter 21 (as also shown in Reference 1 of the Wikipedia page.)
Usually when we talk about disjoint-set data structures, we are talking about a specific implementation called "disjoint-set forest". What is good about this specific implementation is that: 1) it is really easy to implement 2) has a perfect time complexity (almost constant).
You can also find some pseudocode of how to implement disjoint-set forest in the Wikipedia page or in Chapter 21 of the book I've mentioned.
Comment: You can add hyperlinks with the globe/arrow button in the markup toolbar.
Answer: See: http://berkeley.intel-research.net/arahimi/connected/ and http://citeseerx.ist.psu.edu/viewdoc/download;jsessionid=5F7A5FE1F4DCBA968A0B0E99B0593F71?doi=10.1.1.2.5996&rep=rep1&type=pdf


Inserting image in an attribute table in QGIS Composer?

Question: I'm trying to create second page of map atlas. In this page I need to show all records in the range of current atlas page.
I've used Insert Attribute Table tool in composer and it worked. But I need to add a graphic to every record (on the end on attribute table).
Is there a possibility to show image from attribute table in composer or I need to use some separate HTML code?
Answer: It's not currently possible. You may be able to achieve this using a html item with dynamic html, but it's still going to be tricky. You'd either need to prefill an attribute in your table with the html table content, or take advantage of a query which does this on the fly if you're using a spatial database backend.


PF1102T Clock Motor replacement

Question: Can you buy just the clock motor instead of the whole PF1102MT mechanism?
I have this model (240v) on my pool that includes the freeze protection. The clock motor gear will not turn AND I do not know if the gear is even supposed to turn freely. It was working fine until the hard and long freeze here in Fort Worth. Lost power for a couple of days and things froze up. Had to replace some above ground plumbing. When we fired everything back up the clock wasn't working. I can still spin the timer with the on/off tabs and the manual knob all still work to turn the pump on. I see other clock motors that look very similar but do not have the same part number (WG1773 208/277v 60HZ). So my roughly $200 question is: can I buy just the clock motor by itself and save some $$$.
Can you buy just the clock motor instead of the whole PF1102MT mechanism?
Would appreciate any info on this.
Thanks
Comment: Looking similar is bad way of buying a replacement, for anything.  Need to match mounting, voltage and amps,and RPM, at bare minimum.  Make sure it is motor problem first, should usually spin freely if removed.  Try contacting company for parts or model numbers.
Answer: Yes, you can buy just the clock motor from Intermatic. Some good local hardware shops (typically those with heavy property management clientele) stock a variety of them. The number you posted (WG1773) is the clock-motor number you need.
And no, you typically would not be able to grab the toothed gear and turn it by hand...

PF1102T Clock Motor replacement


Is permeable concrete suitable for a houses foundations?

Question: I'm curious if using permeable or pervious concrete for all or part of a houses foundations would provide excellent flood protection? Would it be strong enough to support a house and if not could it be used in conjunction with other construction material or normal concrete to achieve this aim? Thank you!
Comment: Not an expert, but I'm guessing a) it wouldn't be strong enough, and b) you'd get water coming up from below.
Comment: Permiable means water can permiate (come through) it. Why would you want that if you're concerned about flooding?
Answer: If you want to just let floodwater flow through, use a post-type foundation with either no walls or properly designed lightweight breakaway walls that will not impede water flow - plenty of examples of this in new construction in hurricane-prone areas. Park cars or other incidental storage under the house, let water flow right through when it comes in large quantities. Get it professionally designed so it actually works when the water comes.

I can't see that pervious concrete would have any benefit - if a mass of floodwater strikes it, it acts like a solid wall, with predictable (bad) results. For less massive water flows, it leaks. It's primarily of interest/use for reducing runoff from paved areas such as sidewalks or driveways (water can go through, rather than running off the edges in larger amounts.)
Comment: Thank you, I didn't realise pervious concrete would behave this way if used in an actual building I just presumed it would retain and slowly drain water downwards! Thanks again


View not shown upon performSegueWithIdentifier

Question: So I have this splitview. On the left hand side you have the tableView. It has this plus sign. When I tap it I create a new managedObject Woman. I set a stored variable property on detailVC called woman. Then I segue from detailVC to editVC changing data. When I hit the plus sign everything works as it should.
When however I first select another woman in my tableView (showing her data on the detailVC) and then hit the plus I'm not seguing. Anyone know why?
Code:
self.detailViewController!.woman = woman
self.detailViewController?.managedObjectContext = self.managedObjectContext
self.detailViewController?.performSegueWithIdentifier("editWomanSegue", sender: self.detailViewController!)

I looked in the prepareForSegue of the detailVC. In prepareForSegue of detailVC I'm doing:
Code:
let editVC = segue.destinationViewController as! EditWomanViewController
editVC.managedObjectContext = self.managedObjectContext
editVC.woman = self.woman

I put a print on the setting of the woman stored variable property in editWomanVC and yes it is set. Only problem is the View is not shown or loaded (viewDidLoad isn't called for) :s
Answer: I might have found the solution. I have it running now. I solved it by first performing a segue from the masterVC to the detailVC. In the detailVC I'm performing again a segue to the editWomanVC when an attribute of woman is empty in the detailVC. This works. I still wonder why I could not perform a segue on the detailVC with
       self.detailViewController?.performSegueWithIdentifier("editWomanSegue", sender: self.detailViewController!)

though.


The verb "to participate" for an object

Question: Can the verb "to participate" be used for an object (and not a person)? For example: "This equipment will participate in a qualification test." Is this correct?
Comment: Note, first of all, that the preposition _in_ is required with _participate_, which can't have an object by itself. It's "to participate in" that you're asking about. Second, any thing that is sufficiently anthropomorphized can act like an agent, and _participate in_ needs an agent subject. _Ol' Betsy here has partipated in a lot of steam rallies_ is perfectly all right, though _participate in_ falutes a bit too high; _taken part in_ might be a better phrase.
Answer: It doesn't really work in that context.
You'd be better using something like:

This equipment will feature...
Answer: Not grammatically wrong, but sounds unusual. "this equipment is undergoing a qualification test" sounds like a better fit.
Answer: Participate : usually  refer to people or entities like, a company, a state or an organization:

to take part or have a share, as with others (usu. fol. by in): to participate in profits; to participate in a conversation.

In the context you are suggesting,  be subjected to or go through can be used to suggest the idea.
Answer: I would say
<code>Feature
</code>
As participate sounds a bit odd: I'd say it was more for people.
As an aside, you could use feature or undergo in this context, however they would grant the sentence different meanings: feature would imply that the object is going to just be in the test, perhaps helping, whereas undergo would suggest that it is having the test done to it.
As previously suggested by John Lawler the object in question could be sufficiently anthropomorphised such that participate in would make sense, as in the sentence he suggested

The verb "to participate" for an object


What LDS scriptures support the doctrine that Jesus is Jehovah of the Old Testament?

Question: What passages of the LDS edition of the KJV and other authoritative writings and recorded teachings of the LDS support the teaching that Jesus is Jehovah of the Old Testament?
Comment: The answer below is really good. I just wanted to add that [_The Living Christ_](https://www.lds.org/ensign/2000/04/the-living-christ-the-testimony-of-the-apostles-the-church-of-jesus-christ-of-latter-day-saints?lang=eng) states: "He was the Great Jehovah of the Old Testament, the Messiah of the New."
Answer: Jesus has many titles. We know him by "Son of Man", "Savior", "I AM", "The Word", "Christ", "Lamb of God", and so forth. "Jehovah" is the title give to the pre-moral Jesus Christ.
In the book of Isaiah, we read the words of Jehovah:

41:14 Fear not, thou worm Jacob, and ye men of Israel; I will help thee, saith the Lord, and thy redeemer, the Holy One of Israel.
44:6 Thus saith the Lord the King of Israel, and his redeemer the Lord of hosts; I am the first, and I am the last; and beside me there is no God.

Notice how "Redeemer" is used as He speaks or is spoken about.  Jesus Christ is our Redeemer, and Jehovah mentions he is or will be the "Redeemer"
In the Book of John 8:58-59 we read:

58 Jesus said unto them, Verily, verily, I say unto you, Before Abraham was, I am.
59 Then took they up stones to cast at him: but Jesus hid himself, and went out of the temple, going through the midst of them, and so passed by.

Here the Jews recognized that Christ confessed or claimed to be "I AM" who is Jehovah of the Old Testament. This they considered blasphemy and set out to stone him.
In addition to Biblical evidence that Jesus is Jehovah, we have prophets in the Book of Mormon who declared it. Abinidi was one (Mosiah 13:33-34).

33 For behold, did not Moses prophesy unto them concerning the coming of the Messiah, and that God should redeem his people? Yea, and even all the prophets who have prophesied ever since the world began—have they not spoken more or less concerning these things?
34 Have they not said that God himself should come down among the children of men, and take upon him the form of man, and go forth in mighty power upon the face of the earth?

The God of Moses was Jehovah, the God of the Old Testament. Here we see that Moses declared that God (Jehovah) would come to earth and "go forth in mighty power."
The very last verse in the Book of Mormon talks about coming before the judgement bar of Jehovah. But right before it (verses 32-33) speaks of coming to Christ and becoming perfected in him.

34 And now I bid unto all, farewell. I soon go to rest in the paradise of God, until my spirit and body shall again reunite, and I am brought forth triumphant through the air, to meet you before the pleasing bar of the great Jehovah, the Eternal Judge of both quick and dead. Amen.

We know from Isaiah 33:22 that Christ is our judge. This is another example of how Jesus and Jehovah are the same person.
Beyond The Book of Mormon we have modern revelation found in Doctrine and Covenants 110:3-4

3 His eyes were as a flame of fire; the hair of his head was white like the pure snow; his countenance shone above the brightness of the sun; and his voice was as the sound of the rushing of great waters, even the voice of Jehovah, saying:
4 I am the first and the last; I am he who liveth, I am he who was slain; I am your advocate with the Father.

Jehovah (Jesus Christ) appeared to Joseph Smith and others in the Kirtland Temple. I am he who was slain is a good indication Jehovah is Christ who was slain for the sins of the world.
For more explanation here is a bit from the LDS Old Testament Student Manual
Comment: A natural reading of Isaiah 41:14 is that the speaker (Jehovah) is different to the Redeemer, In any case "thy redeemer" of Isaiah 41:14 is the redeemer of Israel, not "our redeemer", so it is a stretch to make this Redeemer (whether or not Jehovah) be Jesus.  Apart from that, I'm having trouble seeing anything in this answer that  tells why Jesus is the *same person* as Jehovah.
Comment: The 12 tribes of Israel were scattered abroad in the land.  It is fair to say  that there are many descendants of Israel alive today. Scattered Israel will be gathered before the coming of Christ. https://www.lds.org/scriptures/gs/israel?lang=eng


Reading plist file at specific index

Question: I have to save some 100 sentences in my app. Each sentence is around 50-90 characters. I can create a .plist file for this. But i dont want to read the whole .plist file, just want to read a specific index. Is it possible?
Answer: I am not sure whether it's possible to avoid reading whole file. But if you want to access a single entry then you can create an array from plist and access the index (i assume that you are already aware of this). It won't take much memory unless your app is already heavy loaded.
Answer: There's no API for reading plist files partially. For 10kB files that's not much of a problem, just read it and discard what you don't need.

Reading plist file at specific index


Attiny85 USIDR Write Speed

Question: The USIDR register for serial communication on the Attiny85 is 8-bit. If I need to send 32-bits, can I write each byte sequentially as fast as the program can run, or do I need to delay between each write operation?
Comment: What does the data sheet and examples there say how and when you are allowed to write to that register?
Comment: You do need to wait for the register to shift out before writing the next value as @asdfesx points out. I think the very fastest you can do is using the technique in this article...
 https://wp.josh.com/2015/09/29/bare-metal-fast-spi-on-avr/
...which describes cycle counting to do sequential blind writes to the SPI buffer, but same trick should  work with the USI buffer.
Answer: The USI in these old Attiny controllers is a very basic building block. It's not able to send data on its own after putting data to a register.
That's a major difference to the USART, UART, SPI or TWI blocks available in most newer Attiny and Atmega controllers.
USIDR is just a register to put data to - there is no buffering and no automatic start of sending data. That means you can write a byte to this register, then you need to start the actual sending (by setting USIOIF to 1), wait for the end of transmission (USIOIF is read as 1) and then you can write another byte. The data sheet shows a block of code for this in chapter 15.3.2 on page 110.
Note that in this example even the clock for transmitting the data is generated in software! That's very unusual for any integrated serial interface module - although you can automate it by using the TIMER0 as the source of the clock.

Attiny85 USIDR Write Speed


Bracha on Tzitzit

Question: If one takes a nap and has the intent to put tzitzit back on, does he need to make a new bracha when he does so?  Is it considered hesach hadaas (loss of concentration)?  Or does his intent obviate that issue?  What is the time period required?
Comment: I seem to recall that prior intent ***interrupted*** is still considered a hefsek. When you're asleep, you aren't actively intending anything about your tzitzit, despite what you thought ***before*** you took a nap.
Comment: Similar: http://judaism.stackexchange.com/q/55799
Answer: I heard from Rav Gershon Meltzer a  posek  in yeshivas Mir that if you had intention to put it back on its not called a hefsek. Same issue with repeating birchas hatorah since you intend to wake soon after. He waif at most its a safek and safek brachos lekula. He suggested to sleep in them none theless in order to accommodate all opinions
Note this site is not meant for halachic rulings and thus should not be followed practically
Comment: Or just put on a different pair upon awaking.
Comment: I guess also have /n mind that you are being mafsik and for sure when you wake up you'll have to make a new brocho
Comment: Truthfully this question is dependent on whether if it falls off even by accident do you need to make a new brocho. The gra says you do

Bracha on Tzitzit


Does an owner of a bond etf get an income even if he sells before the day of distribution?

Question: Suppose an investor owns a bond ETF for 1 month and sells without waiting for the date of income distribution, will he still get paid an income for owning the bond ETF for 1 month? This does not work for stock dividends. I am wondering if it is different for bond ETFs.
Answer: Your ETF will return the interest as dividends.  If you hold the ETF on the day before the Ex-Dividend date, you will get the dividend.  If you sell before that, you will not.  Note that at least one other answer to this question is wrong.  You do NOT need to hold on the Record date.  There is usually 2 days (or so) between the ex-date and the record date, which corresponds to the number of days it takes for your trade to settle.  See the rules as published by the SEC:
http://www.sec.gov/answers/dividen.htm
Answer: Bond ETFs are traded like normal stock.  It just so happens to be that the underlying fund (for which you own shares) is invested in bonds.  Such funds will typically own many bonds and have them laddered so that they are constantly maturing.  Such funds may also trade bonds on the OTC market.
Note that with bond ETFs you're able to lose money as well as gain depending on the situation with the bond market.  The issuer of the bond does not need to default in order for this to happen.  The value of a bond (and thus the value of the bond fund which holds the bonds) is, much like a stock, determined based on factors like supply/demand, interest rates, credit ratings, news, etc.
Comment: This is irrelevant to the question. Either the seller gets "Accrued Interest" or he does not.
Answer: There are two 'dates' relevant to your question: Ex-Dividend and Record. To find out these dates for a specific security visit Dividend.Com.
You have to purchase the security prior to the Ex-Dividend date, hold it at least until the Record Date. After the Record Date you can sell the security and still receive the dividend for that quarter.
---- edit - - - -
I was wrong. If you sell the security after the Ex-div date but before the date of record you still get the dividend.
http://www.investopedia.com/articles/02/110802.asp
Comment: Even with the edit, this is still wrong.  If you sell *on* the ex-date, you still get the dividend.  The literal meaning of ex-dividend is "without dividend."  The ex-date is the first date that the security is trading without a dividend.
Comment: This answer is wrong.  See the SEC site (among others).  The ex-dividend date is the important date for buying and selling. http://www.sec.gov/answers/dividen.htm


Is there a keyboard shortcut to shut down OSX?

Question: Is there a keyboard shortcut to shut down OSX 10.10.1?
Comment: `Command` `Shift` `/` will trigger the help menu. Press `->` to get to the shutdown menu. Then you can scroll up to the shutdown option. Done.
Answer:  Cmd ⌘   Opt ⌥   Ctrl ⌃   Power ⌽  will perform a standard shutdown, asking to if you wish to save open documents first.
There's a list of OS X shortcuts at Apple KB Mac keyboard shortcuts


What does it mean to "simultaneously localize a function in time and frequency domain"?

Question: What does the statement "simultaneously localize a function in time and frequency domain" mean when it comes to signals and systems? What does it mean to localize?
Comment: You might want to check out the [variance formulation of the uncertainty principle](https://en.wikipedia.org/wiki/Uncertainty_principle#Wave_mechanics_interpretation).
Answer: The Fourier transform of a nonzero function with compact support does not have compact support. So if something is "local in time" (i.e. it vanishes outside a finite time interval), then it is not "local in frequency" (i.e. it does not vanish outside any finite frequency interval). Similarly, the inverse Fourier transform of a nonzero function with compact support does not have compact support. So if something is "local in frequency" (i.e. it vanishes outside a finite frequency interval) then it is not "local in time" (i.e. it does not vanish outside any finite time interval).
The above is a qualitative manifestation of this "uncertainty principle". A quantitative version can be stated as follows. Take $f$ such that $\| f \|_{L^2}=1$. Let $\xi$ be a random variable with PDF $|f(x-a)|^2$ and $\eta$ be a random variable with PDF $|\hat{f}(x-b)|^2$. (Here I have used the Plancherel theorem to note that $\| \hat{f} \|_{L^2}=1$.) Then the variance of $\xi$ is at least a constant divided by the variance of $\eta$, and vice versa. Thus the two variances cannot simultaneously tend to zero. So if the "mass" of $f$ is concentrated near some number $a$, then the "mass" of $\hat{f}$ cannot be concentrated near any number $b$, and vice versa.
A helpful document on the subject: http://www2.math.umd.edu/~begue/Expository/Uncertainty.pdf
Comment: @jrodatus A function does not merely tend to zero outside of its support; a function must exactly take the value of zero at points outside of its support.
Comment: what is "compact support"?
Comment: @quantum231 The support of a function is the closure of the set of points where the function is nonzero. For example, if $f(x)=\max \{ 1-|x|,0 \}$, then the support of $f$ is $[-1,1]$. In this setting, a set is compact if it is closed and bounded.
Comment: @quantum231, [http://mathworld.wolfram.com/CompactSupport.html](http://mathworld.wolfram.com/CompactSupport.html) ... _I think_ in grossly oversimplified terms, a function with "compact support" tends to zero outside a particular neighborhood, i.e. it's localized?


ADFS with multiple IDP stops doing the SSO

Question: I'm facing an issue when we enable a second IDP (add Claims Provider Trust), then we are not able to navigate between apps without stopping in the HRD (Home Realm Discovery) page.
Is there a way to control this?
Answer: Depends on the version of AD FS used and your scenario.
You can prevent HRD on the intranet if you are sure they wont need to pick another IDP via HRD. This way users accessing AD FS via a WAP (i.e. on extranet) do HRD but not those accessing AD FS direct (i.e. on intranet)
You can also configure certain relying parties to be associated with specific IDPs. Therefore, if a relying party were associated with just one IDP, the user wont get the choice to do HRD anyway.
See https://technet.microsoft.com/en-us/windows-server-docs/identity/ad-fs/operations/home-realm-discovery-customization for details on these.


How can I disable the auto-opening of a folder when using drag & drop in Nautilus?

Question: The behaviour I would like to disable is shown in the following animation.
Comment: I seem to found [when they introduced it](https://mail.gnome.org/archives/nautilus-list/2001-May/msg00249.html). I didn't have Nautilus, but you could try checking configs at `~/.config/nautilus` directory for relevant timeouts.
Answer: As of Nautilus version 3.17.91, this bug has been fixed by adding an option to disable the "auto-open" behaviour. From the NEWS file:
Major changes in 3.17.91:
...
* Add a preference and disable by default automatic opening of folders while hovering on drag an drop operations (Carlos Soriano)

The default was subsequently changed to "enabled", restoring the "auto-open" behaviour for anyone who doesn't disable it explicitly.
Unfortunately this change wasn't in time to make it into Ubuntu 16.04, which ships with Nautilus 3.14.3. Ubuntu 16.10 shipped with version 3.20.3, so it and subsequent versions should have the option (at least until GNOME decide to remove it again in order to streamline the user experience).
I don't know whether this option is exposed in the GUI, but would expect not. In any case it should be possible to disable the behaviour from the command line with
gsettings set org.gnome.nautilus.preferences open-folder-on-dnd-hover false

Comment: On Debian Stretch, nautilus v3.22.3 there is no GUI option (that I can find), but applying the setting with `gsettings` worked great! Bash completion even works for it. Thank you! You just reduced my stress level.
Comment: Sadly the version on Ubuntu 16.04 LTS is still 3.14.3 which means this setting isn't available (yet). Yet another reason to switch my DE from Unity to something else (anything else).
Answer: It has been reported as a bug in various places, and a topic of multiple discussions:

https://bugs.launchpad.net/ubuntu/+source/nautilus/+bug/1301083
https://bugzilla.gnome.org/show_bug.cgi?id=727790
https://ubuntuforums.org/showthread.php?t=2194812

Although the current direct solution is to re-compile from a modified source, many recommendations have been made to the Nemo file manager:   http://www.webupd8.org/2013/10/install-nemo-with-unity-patches-and.html
Nemo will fix the problem you have, but it won't be the actual nautilus, as it was a fork from an earlier version.
It seems fairly easy and painless to install, so giving that a try may be your best solution currently. (Assuming you don't want to rewrite and recompile nautilus. I don't have personal experience with Nemo.)
Your bug should be fixed in the future though, if the bug reports are of any truthfulness.


Track TCP/UDP Connections for a Program

Question: What is the best way to track a application's internet communication? I've used Fiddler2 with Internet Explorer in the past (with great success on SSL tests). But I'm not finding a easy way to track all the communication between a specific windows program, and the sockets it creates with the operating system Windows 7, 64 bit.
Fiddler would work great, unfortunately, this program would require me to setup a proxy. I'm not sure how to do that for the program I'm trying to read all the communication from. And I'm pretty sure then I'd get the "bucket" for every socket connected to my machine, which would be difficult to filter I believe.
Netstat seems to only give the remote locations being accessed, and not much else.
Answer: I'd give Port Reporter a try for this.

Track TCP/UDP Connections for a Program


Why do some computer power cables not have ferrite beads? What type is usually used?

Question: Admittedly I'm clueless when it comes to electrical engineering. I felt compelled to add a ferrite bead/choke/clamp to my computer's power cord since it was missing one. Would it be helpful? What kind should I get, or are most sold generally the same? Does the wire need to wrap around the ferrite bead, or can I just clamp on the bead and call it a day? Thanks a bunch!
Comment: A better question would be, "why do some computer cables need ferrite beads?". For the answer, see below from Olin.
Answer: A ferrite bead around a cable adds common mode inductance to the cable.  The purpose is to increase the impedance of the cable at high frequencies.  With higher impedance, less power can be radiated or conducted from the cable.
Whether your cable needs a ferrite around it depends on whether you need to reduce the conducted or radiated emissions at high frequencies.  If it is for personal use, then there is little reason to bother.
If you are trying to sell a product, then you have to make sure it conforms to the emissions standards in whatever jurisdiction you offer it for sale in.  In the US, these standards are defined in part 15 of the FCC rules.  In Europe, you generally need to meet CE specifications.
Answer: If you use a handheld ham radio close to your computer, a ferrite bread helps reduce interference from the electromagnetic energy radiated from the power cord.
I just got my ham radio license and when I use my hand held radio at the desk in my home office that has two computers, four monitors, and a 43 in TV on it, there is a noticeable hum when I am listening to the radio. People at the other end don't hear it, but it certainly makes it harder for me to hear them.
I reported the hum to another amateur radio operator yesterday, who explained I need to add ferrite chokes to reduce the RF (Radio Frequency) interference.
I'm now trying to figure out how to get the right size ferrite chokes for all the power cords in the room.
There may be other types of sensitive electronic equipment that are also affected by that electromagnetic energy.
If you have electronics affected this way, adding a ferrite bead to the power cords in the area (get the right size for each power cord and simply snap it on to the cord) should help.
Most people won't need this.


Stuck in US due to coronavirus - travel visa will expire before flights are available

Question: My cousin was supposed to fly back to Poland on May 27, but we just found out yesterday that her flight is cancelled and the earliest flight back is mid July - her six-month travel visa will expire June 12. We must extend her travel visa - we have no choice - how can we do this and not have to pay any fees... this all is due to the coronavirus.
Comment: You should rather be prepared to PAY something if it will avoid some future travel ban or even deportation.
Comment: The visa expiration is irrelevant. What matters is the stamp in the passport (I-94 date).
Comment: @MichaelHampton which is almost certainly what she's referring to, given the six month validity of the thing that's expiring.  The US is very unlikely to issue a visa to a Polish citizen with only six months' validity.
Comment: Are you positive there are no flights to go back to Poland at any date before or after May 27? From the perspective of the authorities, the lack of direct flights or flights by the same airline would not necessarily be considered a good reason not to leave. Even if it's hugely inconvenient or cost €1000+, they will point out that you do have a choice.
Comment: The answer below from James indicates there are still scheduled flights to Poland. Your cousin may have to make a stop (or two, or three) on the way, but if there are indeed flights, she can get back. What research have you done?
Answer: If you haven't already done so, contact your embassy for advice on how to return to your home country. Embassies are organizing repatriation flights that are not advertised and only available by contacting the embassy. For example, there was a Poland-to-US repatriation flight on April 24. Although there may not be another repatriation flight available immediately, it is likely that one will be organized in the next 6 weeks between now and June 12. It may also be possible to return to your home country via a third country (eg return from US to Poland via Germany), but this would be safest if done with advice from your embassy.
Comment: Note that EU citizens that are unrepresented (i.e. they have no embassy or consulate from their own Member State effectively in position to help them) can seek help from the embassy or consulate of any other EU Member State. https://ec.europa.eu/info/policies/justice-and-fundamental-rights/eu-citizenship/consular-protection_en
Answer: Your only real options lie within the guidelines set out by USCIS here. Since your cousin needs a visa, she must apply for an extension. No way around it.
In summary, they state the following:

Generally, nonimmigrants must depart the United States before their authorized period of admission expires. However, we recognize that nonimmigrants may unexpectedly remain in the United States beyond their authorized period of stay due to COVID-19. Should this occur, the following options are available for nonimmigrants:
Apply for an Extension. Most nonimmigrants can mitigate the immigration consequences of COVID-19 by timely filing an application
  for extension of stay (EOS) or change in status (COS). U.S.
  Citizenship and Immigration Services continues to accept and process
  applications and petitions, and many of our forms are available for
  online filing.

Unfortunately that costs money, but it seems it's the only real mechanism the US has for extensions, even in times of a pandemic. USCIS do offer a fee waiver application here
Comment: Might be worth noting that the fee waiver request is only for certain immigration forms and services based on a demonstrated inability to pay.
Answer: There are still commercial flights to Poland flying every day through July, while your guest may not be able to make it out as originally ticketed, there are plenty of alternatives flying from major US cities to Poland. Have you done a search on Google Flights or some other OTA?


CSS and SEO Question

Question: I am currently building a webiste for a client whereby I am using CSS for the menu (not javascript). For the rollovers,  have a background image that contains the regular state and the rollover.
an example code is: BAR
I hide the  and use the background image instead.
My Question Is:
Is this form of navigation good for SEO? Is hiding the  seen as spam by the search engines.  Will search engines even pick up this form of menu??
Please Help
Comment: I don't think it would be a problem...
Answer: Many/most/(all?) search engines will not understand CSS to the degree that they know you're hiding the .  For those, you're fine.
For any that are bright enough to understand your CSS, they'll also understand the reasons why people do that, and will recognise what you're doing.  So for those you're fine too.
Many questions like this one boil down to "Are search engines just clever enough to misunderstand what I'm doing?"  And the answer is no, because it's not in their interests.  As the author of a search engine, you wouldn't add support for noticing CSS-hiding without also adding reliable heuristics to tell the difference between its normal use and its abuse.
Answer: You may use text-indent css property for your
 or  element. This way you won't have to hide it via css. So you'd have something like this

foobar

Then you could have following css:
li a {
  display: block;
  text-indent: -1000px;
  width: 20px;
  height: 20px;
  background: transparent url('/image/path.png') no-repeat;
}

Answer: If you are simply going to hide them using
display: none;
then you will want to check out the question Stack Overflow thinks is most related to yours: Google SEO and hidden elements.
Summary: Google ignores anything it can determine is invisible to humans.

CSS and SEO Question


Using 無理 to empathise

Question: 無理 seems to be a part of some standard phrases whenever I would wish to empathise with a person who in unwell or in distress.
Could someone help with examples of such phrases, and the context where it is appropriate to use.
Answer: I'm guessing the phrase you're referring to is 無理しないでください and its variants. For example, you'd say this when you make a request of someone and realize that it might be a large undertaking or inconvenience, and you want to express that the person you are asking doesn't need to go to such troubles for your sake. More generally, you would use this phrase when you express hope that someone should not overexert themselves, like when they are sick or under some sort of physical or mental distress.
Comment: Are there any other such phrases using 無理?
Comment: @IUnknown there aren't any other fixed expressions that I can think of at the moment, but it's certainly possible to empathize with someone and kind of agree that something is 無理, like if your friend's boss asked them to do a week's worth of work in 3 days you could call that 無理 as a form of empathy.

Using 無理 to empathise


Can any song on guitar be played with standard tuning and without a capo?

Question: Sometimes I see artists I like that either use weird tunings or a capo when they play a song. I don't feel like finding my capo nor changing from standard tuning. Is it theoretically possible to play any song in standard tuning without changing anything? My current hunch is yes but it might just be more difficult. Thoughts?
Answer: It depends what you mean. If you mean play a recognisable version of the song, it's almost certainly possible without a capo or a particular tuning. If you mean getting it sounding the same without a capo or a particular tuning, then in many cases it may be difficult or impossible - the use of the capo or tuning may allow fingerings, chord voicings, and playing techniques that aren't possible without it.
Comment: This is better than the accepted answer. If chord voicings, string combinations, etc. matter in the music, then changing tunes, capo, will likely require some new arrangement of the music. I certainly would not call that playing _ANY_ song in standard tuning. The basic answer is "no" except for a trivial sense of what a guitar "song" is.
Answer: Your question is really two separate questions so I will answer them individually.
Question 1) Is it possible to play any song on guitar without using a capo?
The answer is yes (assuming both guitars are in standard tuning).  A capo makes it possible to use the same chord shapes to play a song in a different key or use a different chord set to play a song in a particular key that you may not like the chords for.  So if you want to play a song without a capo, but play along in the same key as someone using a capo, you would simply transpose the arrangement to match the key that results from playing the song with the capo.  The chart below will help you figure out which key you will need to play in to match the key that is rendered by the capo.

I will use an example to show you how to use the chart above to determine what key to play the song in with no capo in order to match the key rendered with the capo.   Let's say you can see that the guitarist is playing the G, C and D and Em chord shapes.  Since all of those chords would appear in the key of G major, it would be reasonable to assume that the chord set is derived from G major.  If you see that the guitarist is using a capo on the second fret, go down the first column (yellow) and find G (the key from which the chord shapes used is derived) then follow that row over to Column 2 (because capo is on 2nd fret) and you will know that you must play the song in the key of A to match what you are hearing from the guitarist using G shaped chords with a capo on the second fret (A being a full step higher than G in this case).
You can use the information contained click here to convert the chord set from the capo chords to the corresponding non capo chords using transposition.
Of course if you use the same chords without a capo as used with a capo, you will be playing the song in a different key as far as the way it sounds out.  But it will be the same song, just in a different key.
Question 2)  Can any song be played on guitar with standard tuning?
The answer is theoretically yes, but it might not sound the same. Alternate tunings will change the character of how the guitar sounds when played and some alternate tunings render unique sounds that would be difficult to emulate in standard tuning. However many alternate tunings render chords that will sound similar to chords you can play in standard tuning.  Open G tuning for example can be closely approximated in standard tuning, although some chord shapes may be harder to finger than the ones used for open G.
But some alternate tunings may render chord voicings that might be extremely difficult to physically duplicate in standard tuning.  I have seen guitarist who use open tunings where the pitch between adjacent strings spans quite a range.  If you then play a chord shape where there is a wide spread between fretting fingers you could end up with a voicing that would require too far of a stretch in standard tuning to emulate.
Many alternate tunings allow a guitarist to render sounds from his/her instrument that are quite different than what can be easily achieved in standard tuning.  That is why they use an alternate tuning instead of just playing in standard tuning.  So generally, it will be more difficult (if not almost impossible) to use standard tuning to achieve an authentic reproduction of many guitar arrangements that utilize more extreme alternate tunings.
Comment: "A capo makes it possible to use the same chords to play a song in a different key" - it would be more accurate to write 'chord shapes' as opposed to 'chords'
Comment: An example of this is "Romeo And Juliet" by Dire Straits. It's in F major and it's played using open D tuning with a capo on the 3rd fret. While you can play the strumming parts easily, it's going to be impossible to play the intro arpeggios note-by-note without that setup.
Comment: @No'amNewman   Agreed.  I have edited per your suggestion.  Thanks for pointing out how the answer could be improved.
Comment: @mkorman  Good example.  Must be a song you worked out the arrangement for. I have worked out arrangements in alt tunings to allow for alternate picking of single string notes in the melody that you can only do with the altered shapes afforded by the open tuning.
Answer: I think the accepted answer is simply incorrect.  It ignores the fact that any one of us can write a song that is impossible to play on the guitar in any tuning.  For example just include notes out of range, etc.
All the open string chords can be played in a movable chord format.  In such formats the index finger acts as a capo.  Most players will be familiar with bar chords and that is the simplest example, E form and A form.  But in fact the open string C, G, and D forms can all be translated up the neck without any trouble.  For example, instead of playing the open C chord as (x, 3, 2, 0, 1, 0) where numbers are fingers not frets, play it (x, 4, 3, 0, 2, 0).  the index finger rests over the nut.  Sliding this up the neck will result in the chord (x, 4, 3, 1, 2, 1) spanning 4 frets.  This is pretty easy to play without trouble and will never sound "out" due to an open string being out of key.
I've played in every key that exists in standard tuning with a variety of orchestras and bands and never needed a capo.  That doesn't mean EVERYTHING is possible.  If you are trying to arrange a piano piece or violin piece for guitar you will necessarily need to change what is written to make it playable.  A piano player can play 10 notes at once (probably not often) and a guitarist cannot, unless they have a 10 string guitar and even then they are limited.
In closing I think your question is not fair, "play anything"... That is simply not possible.  But playing "guitar" pieces or parts of a song in standard tuning w/o a capo is definitely possible.
Comment: You are pedantically correct, in that it would be extremely hard to play a comprehensively accurate Beethoven's 5th Symphony on a single guitar - but the OP was asking about reproducing other artist's songs that were originally created on guitar. In that case the accepted answer is a valid one.
Comment: From a practical standpoint, I don't think I'd regard open B7 (x-2-1-2-0-2) as being available in a movable form.  Maybe some people could use one finger for the second and fourth string, or manage to kink a finger to play two non-consecutive strings, but I don't think most people could do either in practical fashion.
Comment: Even notes outside the normal guitar range can be played with harmonics and perhaps tapping.
Comment: Not likely with a complex multi voice harmony.   My point is if you just get creative you can force a failure here
Comment: I assumed that that the question was restricted to songs that could be played on a guitar maybe with capo or alternative tuning.
Answer: The thing about capos and weird tunings is that the musician in question found it easier to play that song with the intended emotion with the tunings and capos.
Mostly, capos allow you to play open chords elsewhere on the neck. Could be to suit your voice. Could be to compensate for retuning; I used to see 12-string players tune to D and capo 2 so that the tension was lighter and Easter on the instrument.
Alternate tunings allow things that otherwise would be difficult. Take Richard Thompson's "1952 Vincent Black Lightning". The song has four chords — I, ii, IV and V — and Thompson plays it in CGDGBE, dropping the A to G and the low E to C. This allows Thompson to accompany himself while still being the guitar hero he was meant to be.
A recent cover has Sean Rowe playing the song, but more raw. Gone are the travis-picking flourishes. Is it the same song? Has it changed too much? It certainly doesn't have the low-C bass.
Answer: Yes, it is theoretically possible to play any song in standard tuning, basically musicians change the tuning for their convinience when playing the song, e.g. open G tuning that used by Keith Richard (rolling stone), so he can play G major chord with just one finger, while in standard tuning you need 3 or 4 fingers to play G major chord
Comment: Hi Steve van Christie. Welcome to Music Practice and Theory. As an FYI, answers like this, that seem geared toward driving traffic to a website, need to disclose your affiliation. Otherwise they may be considered spam and deleted.
Comment: im creator of that site (music tools to help or test or clarificaty my answer if the others want to check or clarified it), if it's not allowed, then i'll edited the answer without the answer


Bikur cholim outside the techum

Question: Is one allowed to violate the boundaries and walk beyond techum Shabbat on Shabbat for the mitzvah of Bikur Cholim (visiting the sick)? Is there a responsa or Halacha brought down on this?
Comment: No. Why would they? A mitzvah that happens to have popped up doesn't override the prohibition. The Mishna talks about setting up an eruv techum to visit one's teacher -- implying that techum has to be observed, even if there's a mitzvah at stake (provided it's not a life-threatening matter).
Comment: @KirkBellard just a few things on using @ to ping people. If you comment on a question/answer, the person who wrote that q/a automatically gets notified. No need to @ them. Similarly if there is only one comment to which you respond, that person automatically get notified. You only need to @ people (like I did here) when there are multiple comments and you don't respond to the author of the post
Comment: @Shalom How about when the person visiting the sick person is a *ben zugo* of the ill person who is guaranteed to take away 1/60th of the illness and the ill person is a *choleh sheyesh bo sakana*?
Comment: You're asking if your visit will help when someone's condition is life-threatening? I'd put aside the metaphysics and just ask a medical professional practically. (It's almost always better to have *someone* competent with the patient. Even how the staff views the patient if it appears their family has abandoned them ...)
Comment: Choleh she'ein bo sakanah is the real question. If I recall, there's a responsum in the 1800s to R' Samson Raphael Hirsch about whether we can allow an apple that fell off the tree on shabbos for a *choleh she'ein bo sakana.* Just because they allowed some derbanans does not mean they allowed all of them. (I'm assuming the responsum was more for theoretical halachic sake.)
Answer: No.
You'd be violating techum before getting to bikur cholim.
Yes, circumcision (if on the 8th day proper) overrides Shabbos, but that's the exception; and even then, only the act itself, not its prerequisites. Say the only way to do the circumcision is to forge a new scalpel; the Gemara says that Rabbi Eliezer allowed it, but the halacha doesn't follow him. The same would apply, for instance, if the only way to do the circumcision is to drive there.
Comment: @KirkBellard we can't just apply loose reasoning like that. Say my friend is feeling kind of down (not in a life-threatening way) and says it would make him really happy if he watched me eat chicken a la king. I don't do it, even though cheering him up is a Torah obligation.

Bikur cholim outside the techum


Does wing with bell lift distribution has negative lift at tips?

Question: Does wing with bell lift distribution has negative lift at tips during cruising flight?
Looking at this diagram, tips has very small lift but it is not negative.

https://ntrs.nasa.gov/citations/20180004462  open pdf
Comment: +1 for illustrations
Answer: 1. Summary
As your first plot shows, the optimal Bell-Shaped Lift Distribution (BSLD) is positive throughout its span for an untwisted planform. What's different is that the downwash near the wingtip is negative for the BSLD, thereby giving rise to an apparent thrust and decreasing the overall induced drag compared to the Elliptical-Shaped Lift Distribution (ESLD).
However, for a non-optimal BSLD, you may get negative lift near the wingtips. And when there is geometric/aerodynamic twist, then you will almost certainly get negative lift over some portion of the span at AOAs lower than your design point.
2. Reasoning
Inspired by an Aerocrafty blog (be cautious that the derivation in that article contains some minor errors), we can derive an approximate BSLD without resorting to complex analysis. From Lifting-Line Theory, section lift ($L^{'}$) and upwash ($w$) are given as follows:
$$L^{'}(y_0) = \rho_\infty V_\infty \Gamma(y_0)$$
$$w(y_0) = -\frac{1}{4\pi} \int_{-b/2}^{b/2}\frac{(d\Gamma/dy)}{y_0-y}dy$$
where $y_0$ is the lateral span coordinate, $b/2$ is half span, $\Gamma(y_0)$ is the circulation distribution of the bound vortex, $\rho_\infty$ is the free-stream density, and $V_\infty$ is the free-stream airspeed.
Through a transformation of coordinates (from Cartesian to polar):
$$y=-\frac{b}{2}\cos{\theta}$$
We can write any general circulation distribution as a Fourier sine series:
$$\Gamma(y) = \Gamma(\theta) = \sum_{n=1}^{\infty} {A_n\sin{n\theta}}$$

For an ESLD, the circulation distribution is only the first term, with $A_1=\Gamma_{e_0}$, where $\Gamma_{e_0}$ is the circulation at wing root:

$$\Gamma_e(\theta) = \Gamma_{e_0}\sin{\theta}$$

For a BSLD, we will only keep the first two terms and truncate the rest (noting that due to symmetry, only odd terms remain):

$$\Gamma_b(\theta) \approx A_1\sin{\theta} + A_3\sin{3\theta}$$
Now we can solve for the unknown coefficients $A_1$ and $A_3$ in the BSLD distribution by requiring that a comparative ESLD must have the same total lift ($L$) and root bending moment ($B$):
$$L = \int_{-b/2}^{b/2} {L^{'}dy} = L_e = L_b \tag{a}$$
$$B = \int_{-b/2}^{b/2} {yL^{'}(y)dy} = B_e = B_b \tag{b}$$
That's two equations and two unknowns. The solutions are:
$$A_1 = \frac{b_e}{b_b}\Gamma_{e_0}$$
$$A_3 = \frac{5\Gamma_{e_0}}{3} \frac{b_e}{b_b} \left( \frac{b_e}{b_b}-1 \right)$$
where $b_e$ is the wing span in the ESLD case satisfying (a) and (b), while $b_b$ is the wing span in the BSLD case. That is, we are expressing BSLD as a ratio of span ratio compared to an Elliptical case with the same total lift and root bending moment. Notice that when $b_e/b_b = 1$, we retrieve the ESLD exactly.
2.1 Validation
In the beginning, I mentioned that this derivation is an approximation. But it's not a bad one. Calculating the total induced drag with this formulation, we get:
$$D_i = \frac{2L^2}{\rho_\infty \pi b^2 V_\infty^2} \left[\frac{25}{3} \left( \frac{b_e}{b_b} \right)^4 - \frac{50}{3} \left( \frac{b_e}{b_b} \right)^3 + \frac{28}{3} \left( \frac{b_e}{b_b} \right)^2 \right]$$
Compare this with the exact result from NACA TN-2249:
$$D_i = \frac{2L^2}{\rho_\infty \pi b^2 V_\infty^2} \left[8\left( \frac{b_e}{b_b} \right)^4 - 16\left( \frac{b_e}{b_b} \right)^3 + 9\left( \frac{b_e}{b_b} \right)^2 \right]$$
2.2 Results
Time to get back to the question we began with, can the lift (or circulation) distribution be negative on any part of the span? The plot below shows the circulation distribution of our approximate solution for various ratios:

For our approximate formulation, the most optimal BSLD occurs at $b_e/b_b = 0.8$ ($b_b/b_e = 1.25$ in the plot). As you can see, it's all positive up to the wing tip.
However, as we keep increasing the span (while maintaining total lift and root bending moment), at some point the distribution goes negative near the wingtip. Eventually the bending moment at certain points along the span will exceed that at the wing root (Ref NACA TN-2249).
Comment: Comments are not for extended discussion; this conversation has been [moved to chat](https://chat.stackexchange.com/rooms/111697/discussion-on-answer-by-jzyl-does-wing-with-bell-lift-distribution-has-negative).
Answer: It depends on the angle of attack. The design case of the bell shaped lift distribution is maximum lift. At cruise, angle of attack is lower, lowering the lift coefficient for the whole wing and also at the tips. In cruise lift at the tips is negative.
In Ludwig Prandtl's 1933 paper "Über Tragflügel kleinsten induzierten Widerstandes" he excluded negative lift at the tips because his algorithm would had equated negative lift with negative spar mass. This lift distribution has been used by Al Bowers in his paper "On Wings of the Minimum Induced Drag" (NASA/TP—2016–219072) which is the source of your illustrations.
Why would negative lift be sensible? The Horten brothers used aggressive wing twist in their flying wings and included negative lift at the tips which would only become slightly positive at very high angle of attack, right before stall. Negative wing tip lift means that a downward aileron deflection reduces induced drag while the upward moving aileron increases induced drag on their respective tips, which creates proverse yaw instead of the adverse yaw which is common with ailerons on lift-producing wing tips. By using negative lift on the outermost wing section, the Horten brothers could achieve good flying characteristics even without any fin or vertical surface.
Since the bell distribution of Ludwig Prandtl shown by Al Bowers is for maximum lift and maximum bending moment, it also will show negative lift at practical angles of attack, so it too makes use of negative tip lift to produce proverse yaw. The answer, therefore, depends on the angle of attack at which the lift distribution is plotted, and in cruising flight the answer is yes, it does have negative lift at the tips.
Comment: Comments are not for extended discussion; this conversation has been [moved to chat](https://chat.stackexchange.com/rooms/111696/discussion-on-answer-by-peter-kampf-does-wing-with-bell-lift-distribution-has-ne).


Limit the number of plugins that can be installed in a WordPress installation

Question: I know that is not the number of plugins, it's the quality. But anyway, I want to limit the number of plugins that can be installed on a WordPress installation. Any ideas?
It doesn't matter if the limit applies to all admins including me.
Answer: The most performant way to do this is probably by hooking into map_meta_cap to conditionally disallow the install_plugins capability. There are no database calls involved with that.
Here's an (untested) example:
add_filter( 'map_meta_cap', 'wpse291964_limit_plugins', 10, 2 );

function wpse291964_limit_plugins( $caps, $cap ) {
  if ( 'install_plugins' === $cap ) {
    $plugins = get_plugins();

    // Only allow 10 plugins to be installed.
    if ( count( $plugins ) > 10 ) {
      $caps[] = 'do_not_allow';
    }
  }

  return $caps;
}

I recommend you to watch this video by John Blackbourn to learn more about map_meta_cap and friends.
Answer: There are a few possible solutions you can investigate further to limit the possibility to install plugins.

WordPress will check if the current user can install plugins with current_user_can('install_plugins') before rendering the Add New button. If you create a mu-plugin that will check for the installed number of plugins, you can remove the capability for admins and limit the possibility to install more plugins.
Check with an enqueued JS script the number of plugins and hide/remove the button. This is just cosmetic, if the user knows the route to the installer, plugins can still be installed.

Learn more about must use plugins
Answer: Here's how you can check the number of plugins installed, and add/remove the install_plugins capability for administrators depending on the maximum number of plugins you set. As @iantsch mentioned, it sounds like a must use plugin would be the best place for this. That would prevent other people from messing with the plugin from the dashboard, and it would always be on this way. Also it won't be included in the count of installed plugins in my code below. You could just add this to your themes functions.php file, but then the code is theme specific, not installation specific.
add_action( 'admin_init', 'yourprefix_limit_plugin_installations' );
function yourprefix_limit_plugin_installations() {

    // get administrator role object
    $admin_role = get_role( 'administrator' );

    // check if administrator role object exists...
    if( $admin_role !== null ) {

        // ...get number of "installed" plugins(i.e. deactivated or activated) in your wp-content/plugins folder
        $number_of_plugins_installed = count( get_plugins() );

        // ...set number of installed plugins you want to have as a maximum
        $maximum_number_of_plugins = 29; // take your pick, 29 was just how many I had in my testing environment

        // ...if the number of plugins installed is equal to or more than $maximum_number_of_plugins integer...
        if( $number_of_plugins_installed >= $maximum_number_of_plugins ) {

            // ...remove install_plugins capability from all administrators
            $admin_role->remove_cap( 'install_plugins' );
        }
        // ...else there are less plugins installed than set in $maximum_number_of_plugins...
        else {

            // ...so ensure all administrator users have the install_plugins capability(which is a default WordPress setting)
            $admin_role->add_cap( 'install_plugins' );
        }
    }
}

Comment: One disadvantage of this method is that this results in additional database calls on every page load in the admin because capabilities are stored in wp_options.


creating extended partition

Question: this is my current hard disk status(Running linux Mint LIVE CD)
i have-

Ubuntu 12.04 on 206 GB partition at dev/sda1.
dev/sda2 system reserved.
Windows 7 on 90GB partition at dev/sda3
and linux swap in extended partition.

what i want to do-
I want to install Linux mint KDE on my system for that i want to create a new partition of 30GB(by shrinking the free space available at dev/sda1), i can't create that because i can create only 4 Primary partitions which are already there.
 so do i have to delete the Swap partition? and if i did how to force Mint KDE and Ubuntu 12.04 to use/share same swap space in new logical partition?
Answer: This is an unfortunate situation for you.  Re-sizing sda1 will not allow you to expand the size of the logical partition, because the space must be contiguous, and there is another partition between sda1 and the extended area.
Both Linux installs can share one swap partition.  When you are setting up the partitions, just tell the installer to use the already existing swap.
Have you considered a 2nd hard drive?
Comment: i can't buy new HDD. student life problems. thanks for your time :)
Comment: I understand those problems :)  Shuffling partitions around on a full drive can be a headache!  Luckily you already have Ubuntu installed, which in my very humble opinion is the better Linux distribution.
Comment: can you tell me how to share swap partition between two Linux Operating systems?
Comment: Swap partitions are mounted just like other partitions.  Once the swap partition exists, you just use manual partitioning instead of guided/automatic... then you can say to use the other swap partition.
Comment: If both distros are installed, swap partitions are mounted in /etc/fstab, so you could just tell either distro to mount the other's swap.  Word of warning, this will not work well if you like to hibernate either distro to disk.
Comment: i am not pro can you tell me how to edit fstab? any link ?
Comment: This seems like a pretty good guide, [link](https://help.ubuntu.com/community/Fstab)
Answer: There are a number of possible solutions, but the one I recommend is as follows:

Back up all your important data. Partition moving and resizing operations are inherently dangerous, so things occasionally go wrong when performing steps like the following. Having a backup ensures you won't lose irreplaceable data.
Boot a Linux emergency disc, such as Parted Magic or the Ubuntu installer in its "try before installing" mode.
Launch GParted.
Using GParted, shrink /dev/sda1.
Using GParted, delete both swap (/dev/sda5) and the extended partition that holds it (presumably /dev/sda4).
Optionally, using GParted, expand /dev/sda3 into the space freed by the previous step. Alternatively, you can just leave blank space there.
Create a new extended partition in the blank space left by step #4.
Create a new swap partition inside the extended partition.
Create new partition(s) for Linux Mint inside the extended partition. Alternatively, you could leave this to the Mint installer.

The result will be a legal, if somewhat odd, partition table. One drawback is that this procedure leaves your Windows installation the same size as or bigger than it is now. If you wanted to use some of the Windows space for Mint, you'd need to shrink and move the partition, which is the riskiest type of partitioning operation. It's also likely to leave Windows unbootable until repaired. Overall, it's best to avoid this if possible -- and given your stated goals, it seems to be possible to avoid it.
In theory, both Ubuntu and Windows should remain bootable after this procedure; however, it's conceivable that one or both OSes might be rendered unbootable. If so, you'll need to repair bootability with an emergency system. The details of how to do this depend on the details of the problem, so I won't address those details here; I just want you to be aware that there's a small but real risk of this happening, and that the problem can be overcome if you encounter it.

creating extended partition


bypass SQL injection waf

Question: The server I am pentesting has blind boolean SQL injection, so I was able to guess the DB name to be apps_community.
But it detects words like "information_schema" and drops the connection request.
It also detected the method database() but when introducing a space between (), like ( ), the WAF no longer blocked me.
It also detects -- . Because of that I had to use # for commenting the rest of the query.
I need to bypass this countermeasure to enumerate the tables.
Comment: check this out https://forum.bugcrowd.com/t/sqlmap-tamper-scripts-sql-injection-and-waf-bypass/423
Comment: Have you tried to see what kind of input the WAF is blocking?
Comment: SQLMAP has a variety of tampering scripts ( /sqlmap/tamper/ ), see @Soufiane Tahiri's comment.
Answer: It is impossible to answer your question, as you did not provide any additional details. There are known WAF bypass techniques, which work with certain firewalls. It also depends on the place in the query, where SQL injection occurs. Try to fingerprint your WAF.
Btw, the behavior you have described, looks like WAF reacts to the information_schema and other standard keywords in your request and drops the connection. What makes you think there is an actual SQL injection?
Comment: I was able to guess the database name to be apps_community with boolean SQL injection but when I try to enumerate the infomation_schema the WAF blocks my connection.

bypass SQL injection waf


What sort of vulnerability is this?

Question: I am testing one web application build using PHP. I found one vulnerability in which multiple user can log-in using same browser, without destroying others session. What this sort of vulnerabilities are called and what is the effect of this vulnerability? Many times it happens I find some vulnerabilities, but unable to hack into it, acunetix vulnerability scanner showed this software is vulnerable to blind injection, but I don't know what to do after that.Any readings or advise for that?
Answer: What you describe is not in and of itself a vulnerability.  However, if logging in does not completely over-write client-side session information (eg. cookies or other persistent storage), or if elements of the session are tied to the client's IP address, there is the potential for a privilege-escalation or session hijacking attack.
Answer: I generally inform my clients about the multiple login "issue", especially when there is no last logon information available. Is it a vulnerability? Personally, I don't think it is, it could be a feature where a client sometimes requires to be logged in multiple times (due to poor application development for example). I call this finding "Simultaneous login is enabled" or "Multiple login is enabled".
Whenever Acunetix discovers any form of SQL injection, the next step is to verify it.
Depending on the type of SQL injection, I generally do it by hand. Unless it's timed based blind, I use sqlmap.
In case of just blind sql injection, I'd recommend to perform an action such as the following example:
?id=23 and 1=1 <-- which is a true statement and you should see what ever is displayed when id 23 is requested normally.
?id=23 and 1=2 <-- which is false, sometimes returns a white screen.
If this doesn't work, try using sqlmap.

What sort of vulnerability is this?


Laws to simplify a boolean formula

Question: $$ (\neg A \wedge \neg C) \vee (\neg A \wedge D) \vee (\neg A \wedge B) \vee (\neg B \wedge \neg C) $$
can simplify down to
$$ (\neg A \wedge D) \vee (\neg A \wedge B) \vee (\neg B \wedge \neg C) $$
I've computed the truth tables for the two expressions, and they're the same. But I'm supposed to prove it without using truth tables. What law(s) am I supposed to use?
Comment: P.S. Presumably the reason why the assignment tells you not to use a truth table is because it wants you to get practice using other methods -- it wants to help you learn those methods. You're not going to learn by watching someone else do it; the only way you'll learn is by doing it yourself.  So, you need to try on your own, not hope someone else will solve it for you.
Comment: I don't know what law is supposed to be used to simplify the first expression further. i used wolfram alpha to check if my expression was simplified to it's extent. Thats why i have the second expression. my question is what laws do i need to use to make expression 1 into expression 2 (e.g inverse law, de-morgan's law etc). i can find no way to simplify expression 1.
Answer: You have $(\neg A \wedge \neg C) \vee \text{some_big_expression} $ and you want to show that it's equivalent to $\text{some_big_expression} $.
Simplification rules won't necessarily lead you from the first expression to the second expression. There are systematic ways to test whether two expressions are equivalent, by applying De Morgan's laws in a certain way and other simplification rules (such as $\neg (\neg P) \longrightarrow P$) to transform a formula into equivalent formulas until you reach a disjunctive normal form (or other normal forms, if you apply the laws in a different way). But this doesn't directly get you from one expression to the other.
Another way to prove that two formulas are equivalent is to show that the first implies the second and the second implies the first. Here, it's obvious that
$\text{some_big_expression}$ implies $(\neg A \wedge \neg C) \vee \text{some_big_expression}$, so the difficulty is to prove the opposite implication: $(\neg A \wedge \neg C) \vee \text{some_big_expression}$ implies $\text{some_big_expression}$. Think about what this means: you want to prove that if $P$ or $Q$ holds then $Q$ holds — in other words, if you already know $Q$, then you don't need to prove $P$, it's already implied by $Q$. This is a consequence of two properties of disjunction, idempotency and monotonicity: if $Q \Rightarrow P$ then $(P \vee Q) \Rightarrow (P \vee P) \Rightarrow P$.
So what's left is to prove that $\neg A \wedge \neg C$ implies $(\neg A \wedge D) \vee (\neg A \wedge B) \vee (\neg B \wedge \neg C)$. I'll let you finish. Hint: the right-hand side has both $B$ and $\neg B$, what can you say about these?
Second exercise: use De Morgan's laws to grind the first formula into the second one.

Laws to simplify a boolean formula


Radioactive satellite falls back to earth

Question: I recall a black & white movie from the early 1960's or late 1950's about a satellite that fell back to earth and somehow got wedged in a cave or something similar.  When people came in contact with it, they got trapped in some sort of crystalline structure, essentially becoming part of the (radioactive?) satellite.
Answer: This sounds like "The Flame Barrier"(1958).
Here is the plot synopsis from Wikipedia.
"A woman comes to a small South American jungle village to seek the aid of a reclusive but highly experienced jungle guide, to find her husband who has disappeared while on an exploratory expedition of his own. The husband has specifically gone into the jungle to locate and retrieve an experimental earth satellite, which unexpectedly fell back to earth, out of control, after entering a part of the stratosphere known as the "flame barrier". The guide reluctantly agrees after much persuasion by the woman and also by his ne'er-do-well brother, both of whom accompany him on his trek. Eventually, the satellite is discovered in a cave near the husband's deserted campsite, and is found to be contaminated by an alien life-form which doubles its size every few hours. The problem then becomes one of saving the world."
I can't find any good videos or photos, but have included the IMDb page link below. If you read the 2nd and 3rd user review, you'll see it matches your description.
http://www.imdb.com/title/tt0051618/?ref_=nv_sr_1
Comment: That sounds like it!  You, my friend, are a rock star!  I will look for this, and if I find it someplace online, I will report back here with great glee and gusto.  Thank you, friend!


Possible mistake in the solutions?

Question: This is from Kleppner's introduction to mechanics and I've been having trouble making sense of the solution in the solution manual for quite a while and I've concluded that its wrong but I need some sort of confirmation. I have trouble grasping why $\dot x_1$ and $\dot x_2$ are assumed to be the same $wl/2$ instead of using conservation of momentum to find the new combined velocity. I mean, where did the extra energy even come from? The question:
And the solution given in the soln manual:
Answer: I believe you are correct. According to the solution, $m_1$ instantaneously goes from being motionless to moving with velocity $\frac{1}{2}\omega l$, requiring an instantaneous non-zero impulse applied on $m_1$, which this system cannot provide. As you indicated, conservation of momentum can be used after the moment $x_2 = l$ to describe the motion of $m_1$ and $m_2$.
Answer: They seem to assume that the spring cannot be extended to a length beyond $l$ so after it is fully extended the two bodies indeed move with the same speed.
Without that assumption we can proceed as follows: after $t = \frac{\pi}{2\omega}$ the equations of motion are
$$m_1\ddot{x_1} = k(x_2-x_1-l)$$
$$m_2\ddot{x_2} = k(l-x_2+x_1)$$
so adding the two equations gives $m_1\ddot{x_1} + m_2\ddot{x_2} = 0$, or $m_1\dot{x_1} + m_2\dot{x_2} = \text{const}$.
Therefore $$\dot{X} =\frac{m_1\dot{x_1} + m_2\dot{x_2}}{m_1+m_2} = \frac{m_1\dot{x_1}\left(\frac{\pi}{2\omega}\right) + m_2\dot{x_2}\left(\frac{\pi}{2\omega}\right)}{m_1+m_2} = \frac{m_2\omega l}{2(m_1+m_2)}$$

Possible mistake in the solutions?


How can I set a custom response header for pylons static (public) files?

Question: How do I add a custom header to files pylons is serving from public?
Answer: a) Let your webserver serve files from /public instead of paster and configure it to pass some special headers.
b) Add a special route and serve the files yourself ala
class FilesController(BaseController):
    def download(self, path)
        fapp = FileApp( path, headers=self.get_headers(path) )
        return fapp(request.environ, self.start_response)

c) maybe there is a way to overwrite headers and i just dont know how.
Comment: I'm wondering if return forward(FileApp(path, headers=...)) would be better.  (forward comes from pylons.controllers.util.)
Comment: The `FileApp` method works great. Thank you so much - finally a way that actually works!
Answer: With a recent version of route, you can use the 'Magic path_info' feature, and follow the documentation from here to write your controller so it calls paster.DirectoryApp.
In my project, I wanted to serve any file in the public directory, including subdirs, and ended with this as controller, to be able to override content_type :
import logging
from paste.fileapp import FileApp

from paste.urlparser import StaticURLParser
from pylons import config
from os.path import basename

class ForceDownloadController(StaticURLParser):

    def __init__(self, directory=None, root_directory=None, cache_max_age=None):
        if not directory:
            directory = config['pylons.paths']['static_files']
        StaticURLParser.__init__(self, directory, root_directory, cache_max_age)

    def make_app(self, filename):
        headers = [('Content-Disposition', 'filename=%s' % (basename(filename)))]
        return FileApp(filename, headers, content_type='application/octetstream')

Answer: In a standard Pylons setup, the public files are served from a StaticUrlParser. This is typically setup in your config/middleware.py:make_app() function
You need to subclass the StaticUrlParser like Antonin ENFRUN describes, though calling it a Controller is confusing because it's doing a different purpose. Add something like the following to the top of the config/middleware.py:
from paste.fileapp import FileApp
from paste.urlparser import StaticURLParser

class HeaderUrlParser(StaticURLParser):
    def make_app(self, filename):
        headers = # your headers here
        return FileApp(filename, headers, content_type='application/octetstream')

then replace StaticUrlParser in config/middleware.py:make_app() with HeaderUrlParser
    static_app = StaticURLParser(config['pylons.paths']['static_files'])

becomes
    static_app = HeaderURLParser(config['pylons.paths']['static_files'])

Answer: A simpler way to use FileApp for streaming, based on the pylons book. The code below assumes your route provides some_file_identifier, but the other two variables are "magic" (see explanation after code).
class MyFileController(BaseController):
  def serve(self, environ, start_response, some_file_identifier):
      path = self._convert_id_to_path(some_file_identifier)
      app = FileApp(path)
      return app(environ, start_response)

Pylons automatically gives you the wsgi environ and start_response variables if you have variables of those names in your method signature. You should not need to set or munge headers otherwise, but if you do you can use the abilities built in to FileApp to achieve this.


Is there a Snipping tool for WIndows XP

Question: Is there a tool available for Windows XP which is similar to the Snipping Tool for Windows 7?
Answer: Try the free Greenshot screen capture utility.  After installing it, you just use the print screen button as normal but now it comes up with a selection tool instead of screen snapshotting the entire screen.
Answer: I found the following information on Microsofts website here. Typos and all! XD

Sinpping tool is included in Experience Pack which can be downloaded from here.
Microsoft Experience Pack for Tablet
  PC can work with Windows XP. However,
  please pay attention that there are
  some sepecial reqestments for Windows
  XP as below:

Windows XP Service Pack 2
Microsoft .NET Framework 1.1
Windows Media Player 10 (required for Media Transfer)
At least 50 MB of available free space on your hard disk
Comment: The installer will not run, insisting that Tablet PC Edition is required.
Comment: Yes David, it does not work on Windows XP using the current version. I have also found Greenshot quite nice.
Comment: +1.  This is a better answer to the question if only because it IS the Snipping Tool, haha.
Comment: @SamBrightman: are you doing this on Windows XP? That is the ONLY operating system that this question applies to. Also, I was simply identifying how to use Snipping Tool on Windows XP, which is exactly what the questioner wanted. I would highly suggest Greenshot and I use it daily at work. Try Greenshot like the other answer insists.
Comment: Unfortunately that "experience pack" download seems to only be for windows tablets running XP, or something like that, not desktops.
Answer: First, I'd like to mention the possible option of simply using what is built into Windows XP.  Press Print Screen to capture a whole screen, or hold Alt-Printscreen to capture just a current window.  Either way, paste the resulting graphic into a program such as MS Paint, which can be used to make further edits.
However, for those who wish alternative options, I found quite a few from the goldmine of a thread that David provided.  That thread is at Microsoft Social Media site.  However, the thread also contained a number of other details to make things work, and also referred to several other options.  Since there were some later modifications to earlier instructions, I simplified the situation by compiling the details here for convenience.
(Note that I don't have a system running XP handy, so, for now, this is all based on hearsay.  I'm presuming that people interested in this answer may be able to test this.)

    Use official code by Microsoft

        Obtain the Microsoft Office XP Pack for Tablet PC (Tablet Pack).  (This appears to be the correct name for the software, and is the same software mentioned in David's answer in this Stack Exchange question.  His answer appears to be based on Morgan Che's answer from the Microsoft site.)

Download page for Microsoft Office XP Pack for Tablet PC (Tablet Pack)

        If you have Windows XP for Tablet PC (technically a different OS than Windows XP), then installation should be straightforward.

        If you want to try to use this with regular Windows XP, that may be an option, but will involve third party software, and more work.

            Possible alternative (if this is suitable trustable by you...  This is not necessarily recommended by me...)  Third party download for Snipping Tool and the Dev Kit 1.7 posted by "cexeh" on the Microsoft Thread.  Whether this is more trustworthy, or less trustworthy, than any of the other software (like isxunpack, perhaps) is a detail I'm not trying to determine for you.  Download at your own risk.

            I suggest starting with the requirements mentioned by Morgan Che: XP SP2, .NET Framework 1.1, Media Player 10, 50MB of disk space

                dapatoumba's answer provides instructions, and says, "Note that the tool will not run on nLited Windows installs without IE/WMP".  So if you used "nLite" to install Windows without that common functionality, then this may not work.

            Obtain additional required software

                i6comp (i6cmop02.zip) (TOOGAM's note: The ftp.sac.sk, used by this hyperlink, is recognized as generally being trustable)

                isxunpack (isxunpack download)

            Additional software that might be helpful

                dapatoumba's answer, on the Microsoft thread, also said to install WinRAR.  However, there isn't any clear reason why...  I suppose this is to Extract Launcher.msi from Microsoft's OPSetup.exe (step 3 of NSKSAM's instructions in the original thread)

 Microsoft Windows XP Tablet PC Edition Software Development Kit 1.7 may be helpful if the program complains about "The DDE server did not acknowledge the command, within the time allowed. Application=, Topic=".  (That error was reported by somebody who mentioned this Dev kit as a solution.  That person was using XP Pro Service Pack 3.)

            Extract Launcher.msi

                Apparently this is what WinRar is helpful for

                    Unrar did not recognize the OPSetup.exe as a valid file.  7-zip could extract from the required file, but did not seem to make a file called Launcher.msi

                To do this, use Explorer.  Right-click on the OPSetup.exe file.  And choose "Extract to InstallExperiencePack\".

                Install the software by running this command: "msiexec /a Launcher.msi"

                After installing, rename Microsoft\Experience Pack\Data\Sniptool.dat to SnipTool.exe

                Use: isxunpack.exe SnipTool.exe

                Copy the i6comp.exe (downloaded earlier) to the resuliting Disk1 sub-directory

                From that directory, run: "i6comp.exe e data1.cab"

                Ignore error messages, and enjoy SnippingTool.exe

    Or, use some other options, such as one of these:

windows xp snipping tool third party application, with source code available, by StratMan123 (who posted to the Microsoft thread)

Snippy (mentioned by Ruth, Brunette-31, on the Microsoft thread, who noted this is "not as fancy or as nice")

        MWSnap v3 (recommended by S. Buchanan, Sawdustpsycho, on the Microsoft thread.  No hyperlink was provided.)

HP Smart Web Printing

That is completing the roundup of information from the Microsoft thread.  Note that there may be other options, too, like "Greenshot" which is mentioned in another answer here.
Comment: excellent omnibus answer! Thanks for your time! ( Can't believe this hasn't received any other votes! :-/ )
Answer: Here's one I developed a while back, it works just like Snipping Tool in Windows 7:
http://glassocean.net/snip-tool-a-free-snipping-tool-compatible-with-windows-xp/

Is there a Snipping tool for WIndows XP


Hidden layers in Neural Networks

Question: What is the use of Hidden layers in Neural Networks? How do we know the role of each hidden layer?
Answer: Neural networks are universal function approximators. To approximate any function, you need to be able to model it in a non-linear way.
If you consider Neural Network with just input-output layer, then it is just linear approximation (i.e. visually equal to drawing a straight line to divide the example-categories). Hidden layers allow introducing non-linearities to function.
E.g. think about Taylor series. You need to keep adding polynomials to approximate the function. You can draw an analogy (although weak) between adding the polynomials and adding the hidden layers in the neural network.
The role of each hidden layer cannot be easily known beforehand.
Having  too many hidden layers will make the Neural network to overfit the function ("high variance"). Having not enough hidden layers will make the Neural network to underfit the function ("high bias").
Comment: You are describing a logistic regression. The decision boundary is still a straight line. If you added higher order terms to parameters, then you could draw non-linear decision boundary.Maybe this helps: http://www.holehouse.org/mlclass/06_Logistic_Regression.html (it seems to be notes from Andrew Ng's Machine learning -course).
Comment: I am confused of one thing. What if I have just input-output layer without any hidden layers and I use sigmoid activation function to determine output units. In that case it will we non-linear. Then why hidden layer in this case?
Comment: Yup. Thanks. Now it makes sense....Got it. One last doubt. How do we determine the values of weights for mapping?
Comment: For that I suggest to investigate the backpropagation -algorithm.

Hidden layers in Neural Networks