Red5-Recorder not working

Question: I have done with red5 server installation.everything works fine in server installation..all the demo red5 applications are working perfectly. but I'm getting problem with red5-recorder..I'm getting an ERROR:could not connect to the server rtmp://127.0.0.1 ..Is there any other modification I have to do in the code?
Answer: ERROR:could not connect to the server rtmp://127.0.0.1 is caused by
if(Application.application.parameters.server!=null) myRecorder.server= Application.application.parameters.server;
which defaults to nc.connect(myRecorder.server) which returns 127.0.0.1/red5recorder
In order to get around this, you can pass along the server= FlashVar.
Edit red5recorder.html and add this in the appropriate place (after line #91):
"FlashVars", "server=rtmp://your.external.server.ip/red5recorder"
This is because the swf is downloaded and run client side, and needs to connect to your server's RTMP service. It can't connect to 127.0.0.1/red5recorder because that's your PC. This is why you set the server= paramerter. :-)
I hope that helps.
Comment: This did not work for me. It still comes up with error message.
Comment: Could you show the error messages as well as the exact steps you took?
Answer: I created a new web app for Red5Recorder as indicates here with the name "red5recorder" because that's the name the recorder use to comunicate with. (see the Recorder.as file in the sources) and after restarted the server it started to work. The output file called "video.flv" is in the streams/ subdirectory.
I hope this helps you.
 Cristian

Red5-Recorder not working


Can I move my logic board between different models of MacBook Air?

Question: If I take out my logic board in my MacBook Air 2011 11-inch i5 2 GB RAM and put in a MacBook Air 2011 11-inch i7 4 GB RAM, will it work? If not why?
Comment: what are you doing ? and why would it not work, since all except keyboard and the screen are on the logic board.
Comment: i think it should work but im not sure so i wnted some help i cant see why it wouldnt surely all of the ports are the same.
Answer: Yes, it will work.
The only thing you need to understand is that logic board is a determinative component in a MacBook and all the other parts (like flash drive, Wi-Fi module, etc.) just connected to it. But all of them are completely changeable.
So if you got two MacBook Air 11" 2011 you can interchange their parts in any order you want.
Just don't forget to use credible disassemble guide. I strongly recommend you ifixit.com.


504 error on home page of Craft 3 website

Question: Recently, I developed a Craft 3 website. Its working perfectly on development server. But after deploying to another server, I am getting 504 error for home and all front end pages while Craft dashboard is working perfectly. I looked into logs but didn't find anything related to it.
Answer: This is kind of hard to debug without any logs, but because 504 is a gateway timeout error, I would start by checking if your site uses any external services, other servers it tries to reach (only from within your templates, because the admin works fine).
This could be anything from Google's geolocation API to an external image service, that can not be reached because of server settings on either side.
Is there anything in your server logs, or could you activate logging for your server to get more details?
Comment: Thanks Paul, there was problem with SEOMatic plugin. I disabled it and site started working. I am going to do further investigation to sort out the problem of SEOMatic. Thanks again :)
Comment: +1 Had the same strange issue with 504 error - I switched branches on repo, I think I dropped my security key from env configs. Either way was able to disable SEOmatic and then all worked again. Very strange
Answer: I was seeing similar issues and in the end it turned out to be a missing image.
In my case it was the Creator (Entity Brand) logo missing. It had been picked but the file was missing locally. After reuploaded, it resolved the issues.
I wrote the issue here -> https://github.com/nystudio107/craft-seomatic/issues/418


Can we use fractional regression for a dependent variable that is made of continous numerator and denominator?

Question: I have a dependent variable that is a ratio, i.e. it takes the values between 0 and 1. Some 30% of values are 1s. The dependent variable measures the distribution of funds, i.e. it is calculated just like so: amount of distributed money / the total amount of proposed money. So the ratio comes from continuous data (the amounts of distributed and proposed money).
I am building a model to see what factors influence the disbursement rate.
I was told that a fractional logit regression could be appropriate in such a case? Here is a source that talks about fractional regression.
What puzzles me is that this source mentions "raw counts" in the introduction:
"Introduction
It is sometimes the case that you might have data that falls primarily between zero and one. For example, these may be proportions, grades from 0-100 that can be transformed as such, reported percentile values, and similar. If you had the raw counts where you also knew the denominator or total value that created the proportion, you would be able to just use standard logistic regression with the binomial distribution. Similarly, if you had a binary outcome (i.e. just zeros and ones), this is just a special case, so the same model would be applicable. Alternatively, if all the target variable values lie between zero and one, beta regression is a natural choice for which to model such data. However, if the variable you wish to model has values between zero and one, and additionally, you also have zeros or ones, what should you do?"
Do you know if this suggests that a dependent variable must necessarily come from count data if we are to use fractional regression, or can it come from continuous data like in my example?
Appreciate any useful sources and comments.
Answer: It appears to me that it is not necessary that the dependent variable would come from count data. Please see the source one and source two, which give examples of studies that have used fractional regression with fractional dependent variables that are based on various types of data.


Black background on linux mint 19 after login

Question: I have been the whole day with this problem and I don't know what else to do. I have a Linux Mint 19 on an Asus R510J and until yesterday, everything was working fine. But today, when I started the computer and made the login (which looked normal), the desktop looked with black background and no panel, although I could still see the icons and the mouse, and I could actually open that programs (only that because I had no other option on the screen), but I couldn't even open a terminal. Besides, the icons of the windows I could open were incorrect, as they didn't show the 3 icons (close, max, min) at the right top corner).
After digging a little about it, I did the login in Software Rendering mode, and it looked fine, but I can only open Google Chrome, Firefox and the FIle Manager. I can see the panel, and watch the list with all programs, but when I click, they don't open (neither the terminal).
PS: Yesterday, I installed Python 3.7 following this https://www.itsupportwale.com/blog/how- ... ntu-18-10/ It's the only difference with previous days
What is happening and what can I do to solve this?
Thank you
Answer: It turned out it was a problem with the Python installation.
I finally got it working following this: https://forums.linuxmint.com/viewtopic.php?t=305987&p=1719076


Why are my audiobook chapters out of order?

Question: Every time I add an audiobook from mp3 files via iTunes, the chapters are completely out of order even though they have the correct Track numbers in iTunes:
Comment: What have you already tried to fix this?
Comment: When you say they have the correct track numbers, do you mean that the files are numbered correctly, or that the track numbers in the audio file metadata are correct?
Comment: @fsb I've verified that all the track information is correct, but there doesn't seem to be any options at all in iBooks about sorting.
Comment: @the_storyteller The files are number correctly AND the track numbers are correct. iBooks just isn't sorting them correctly for some reason :(
Comment: Can you post a picture of the metadata for these from iTunes?  Every answer I've seen on the web states the metadata on iTunes needs to be correct because you can't change it on iOS.  [This answer](https://superuser.com/a/530248/584424) says how to check it but you might've done that already.
Answer: It's sort of the same solution to "Songs show up as individual albums in iOS Music app."
Make sure the files have the correct tags for album, artist, track, and title.
Then in iTunes:
1) Upload the first track to Music.
2) Upload the rest of the tracks to Music. (Or you can upload all the tracks including the first one -- iTunes will ignore the duplicate first track.)
3) Select all the tracks in iTunes, right click, then select Get Info > Options > media kind > Audiobook, and click OK.
iBooks should list the audiobook in order now.
The key is that the first track of the audiobook must be uploaded first.
P.S. You can also upload multiple audiobooks by doing steps 1 and 2 on the first audiobook, then repeat for the other books. And then select all and do step 3.
Or do step 1 on each audiobook, then do step 2 on all the audiobooks together in one go, then select all and do step 3.
Answer: Try organizing the chapters in iTunes per Organizing audiobook chapters and re-syncing. The Apple version of the script to fix them up is at the bottom. Follow the link from the text for a Windows machine.
Answer: I have been struggling with this for the last few years and I finally got a solution to work today!!   I used the id3v2 utility on linux and set the track frame as "N/M" where N=Track number and M=Total number of tracks.  Then import the mp3 files to iTunes and now you should see the files grouped as an album with the tracks already in the right order.  Select the album, command-click or right-click and choose File Info -> Options, change the Media Kind to Audiobook, and you now should have your audiobook in order!
The id3v2 utility is a sourceforge project.  Its page is here:
http://id3v2.sourceforge.net/
I wrote a shell script to set the N/M track.  You need to put each audiobook in its own directory, and run this script in each directory, for this script to work.
$ cat set_audiobook_track_numbering.sh
<code>#
# Sets track numbering in all MP3s in current directory
#

COUNTER=0
TRACKCNT=`/bin/ls *.mp3 | wc | awk '{print $1}'`
for F in *mp3 ; do
   let COUNTER++
   echo id3v2 -T "$COUNTER/$TRACKCNT" "$F"
   id3v2 -T "$COUNTER/$TRACKCNT" "$F"
done

echo Done.  Set track number in $TRACKCNT mp3s.
</code>
Comment: I appreciate the answer but this is crazypants. Android "just works", WTF is wrong with iPhone?


why would an alpha particle ejects neutron when bombarded on berreylium?

Question: when an alpha particle hit berrelyium it emits neutron. Does the alpha particle causes unstability to the nucleus or any other reason?
Comment: Alpha particle is _itself_ a nucleus, just a relatively little one. Then again, beryllium is not awfully large either. Imagine a head-on collision of Earth and Mars; I have a vague feeling you wouldn't want to describe it in terms like "_Mars causes instability to Earth_".
Comment: So then it is due to the kinetic energy of the alpha particles. Is this true?
Comment: Yes, you may put it this way.
Comment: I disagree with @IvanNeretin's comment. This is a quite well known nuclear reaction, 9Be($\alpha$,n)12C (amongst other things well known as the neutron spark plug for the first atomic bomb). The 13C intermediate nucleus that is formed is some 10MeV above the ground state. One relaxation path is through releasing a neutron to leave 12C. (Remember that you need to conserve both energy and momentum in the center-of-mass frame of the interaction.) The overall Q value for this reaction is about 5MeV.
Answer: The reaction can be regarded as a fusion reaction, the fast moving helium nucleous has sufficent energy to overcome the electrostatic repulsion of the positvely charged beyllium nuclous. What happens is that the alpha particle will enter the berylium nucleous to form the product.
The product will be carbon 13 in an excited state, the carbon 13 could relax down to the ground state by the emission of gamma rays (photons) but by the ejection of a neutron it is able to convert itself into the very stable carbon-12.
In the same way as in chemistry we have the chemcially very stable noble gases (full electron shells) in nuclear science we have some nuclides which are blessed with additional stability.
Carbon-12 has both an even number of protons and neutrons which will increase its stability more than a odd,odd, even,odd or odd,even nuclide. Also there are some magic numbers which correspond to complete shells of nucleons (protons and neutrons). Carbon-12 is not one of these magic nuclides (full shells of protons and/or neutrons) but it is more stable than carbon-13.


How is probability distribution type decided before applying maximum likelihood estimation?

Question: What I can't grasp for a long time is how is the assumption about the probability distribution type made? Why do we assume that the human height is distributed exactly normally? Why not any other function that is numerically/shape-wise close to Gaussian? What is the reasoning behind it? I did not manage to find any criteria about how the probability function is selected. Why is function F over function G in a particular case? Do we just essentially guessume it?
Answer: To choose a distribution, we must carefully consider the nature of the data being sampled. Some important criteria include (but are not limited to):

Discrete vs. continuous
Non-negativity
Symmetry
Censoring and truncation.

Based on this, we can narrow down our choice for a reasonable distribution function. There are various tests that can be implemented to check of the choice of the distribution (e.g. $\chi^2$ goodness of fit test).
In your height example, let's look down the list. Clearly height is a continuous variable, so we can rule out discrete distributions as our choices (Poisson, negative binomial, etc.). Height is a non-negative variable, but, I would guess, that 0 is sufficiently far from the mean (in terms of number of standard deviations) that fitting a normal distribution is not problematic. Whoever choose the normal distribution must have looked at a histogram of the data, and decided the distribution was very close to symmetric (there are tests for this as well). Finally, censoring or truncation is not an issue in height data, so we can disregard criteria 4.
Comment: So essentially we are saying "Here are our criteria, everything that satisfies them could be our distribution function, but we choose a particular one, because it is comfortable for us to work with it"?
Comment: That's how I would do it. And once you have a few reasonable choices narrowed down, you can check goodness of fit criteria or conduct tests to decide which one is most appropriate.
Answer: In some cases, the Gaussian assumption can be justified by the central limit theorem. For instance, if the data consist of averages of heights of students in each school, we can treat each average follows a Gaussian distribution.
In general, the Gaussian assumption can be too restrictive so people tend to use the sub-Gaussian assumption which includes all distributions with fast-decaying tails including Gaussians, all bounded distributions and so on. In this case, you cannot use the maximum likelihood estimation since we do not specify any density function. But still we can prove many commonly used estimators such as sample mean, median, quantiles behave in some optimal manner.


Are there any differences between later, latter and last?

Question: Can I say a later bus? Or should I say a latter bus? For example I was in a hurry to catch a ... bus to the city centre.
Comment: This question appears to be off-topic because it is about homework
Comment: 1) we do not do your homework for you. 2) please visit http://ell.stackexchange.com/
Comment: This actually might make a good question, but as it is constructed it appears you are unwilling to make any effort to understand or learn. You are treating the site as a mere machine, when you punch in the question and expect an automatic response. EL&U does not work like this. Please view the help centre for tips on how to ask [better questions](http://english.stackexchange.com/help/asking)
Comment: Ooh, that is better! But please check your spelling. **Differences** and the pronoun, **I**, is always capitalized.
Answer: Yes there are.
When using a list of items you can say the former and latter ONLY if that list comprises TWO items. Do not use A, B and C, of which the latter, as that is not grammatical.
When using a list of two items, "I am thinking about cooking and ordering food, but I already decided to do the latter." then it is grammatical to use the word "latter". The same applies to former. (Source: The blue book of grammar 11th edition by Jane Straus, page 95, confusing words and homonyms. The exact example in the book is this, "He offered a trip to New York, Chicago, or Tarzana. She chose the latter. Oh no she didn't. Latter can't be used when there are three (or more) options. It applies only to sentences like 'He offered a trip to New York or Tarzana, which makes New York the former, Tarzana the latter.' When there are more than two people or things mentioned, use last
Your question asks about "later" as well. Later means more time has passed, this has nothing to do with the others (semantically speaking), but the spelling and phonetics of the word are very similar; therefore, the category confusing words and homonyms applies perfectly. It is a confusion based on how the word sounds and is written down, but the meaning of the words latter and later differ, the for latter meaning time and the former meaning something out of my two part list.
Answer: You certainly can say "a later bus." To say "a latter bus" would be incorrect, unless there were only two and you were indicating you were going to take the later, latter and last one.
Comment: No, *the latter bus* could be correct if you had previously mentioned two. I can't offhand think of any correct use for *a latter bus*.
Comment: Thus my conditional "unless...."


How can I replace ceiling gypsum board and loose fill insulation at the same time?

Question: I lost most of a ceiling panel due to water saturation and collapse. It was removed along with insulation residue and a temporary fiber board panel tacked in in its place. Now I would like to install the permanent gypsum board, full 4 by 8 but the problem is how to restore loose fill insulation layer (only) on top of the new rock but the joist would interfere and there's no practical way to blow or throw it going into the attic. I have a drywall jack/lift. I am looking for good idea for lifting insulation along with the panel and thought maybe someone else has encountered this kind of rehab challenge.
Comment: Is there a reason you want to use loose fill rather than fiberglass batts or foam panel insulation?
Comment: 1. The undamaged ceiling is covered with loose fill.
Answer: Hoisting the insulation with the drywall panel is a bad idea. I would instead install fiberglass bat insulation between the joists. You could use the kind that is faced with paper and staple it to the joists for added support. If just plain batts are used then you may need to add some type of staple on stripping to help hold the batts in place. Install all of this except for one small area where you can go up and put in more of the loose insulation above the fiberglass if that is desired or needed. Finally close off the small area by pushing up an oversized bat that covers the opening from above and then install the final piece. If using the paper backed staple that in place. If the ceiling previously had some type of vapor barrier you need to install similar material on the bottom of the ceiling joists.
Now you would be ready to install the new ceiling drywall.
Comment: Unfaced batts are usually held in place overhead with stiff wires, bowed between the joists, spaced every foot or two.
Comment: @bib, Are you saying that those wires are indispensible for pressing a batt (down into the joist cavity against rock and joists to ensure against "leak"? MichaelKaras, Bib: As I understand your answer, with faced batts I would tack the facing to the bottom (floorward) edges of the joists. Or if faceless, improvise something else (live tape/paper) to tack in place as batts are pushed up between joists? Now, with foam boards, where tight fit is critical, is there a suitable caulk/sealant that could hold them in place? Finally, it's 4in joists. How that impacts batt or board thickness?
Comment: @Lex When installing batts overheard, you want them to be flush with the bottom of the joist and not be compressed. Leak is really not an issue. The [wires](http://www.homedepot.com/h_d1/N-5yc1v/R-100375360/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=insulation+batt+wires&storeId=10051#.UIfdmm88CSo) are bowed between the joists to hold them up since you dont have the facing to tack to the bottom of the joists. Batts are sized for different joists, for yours 3 1/2 inch thick. Foam boards are cut or precut to fit tightly on their own, but can be sealed in with foil tape.
Comment: @Lex - the paper or foil faced batts are stapled from the bottom side of the ceiling joist with the fiberglass fit up between the joists.
Comment: @bib - I have also seen wires used to support the batts. They have some advantages such as not stretching but....in most cases the proper width batts simply hold themselves in place. In this case because there may be added insulation placed above the batts before the drywall is installed the use of plastic strips is an easy / quick method. Think of plastic on a roll similar to the common yellow "caution tape". I simply cut 4" wide strips off the end of a roll of poly.


How do I get Visual Studio's "Publish Website" to 1. not overwrite web.config & 2. promote copies of dlls that were referenced from my GAC

Question: I started using a a library which I reference from the GAC during development. I want the dll included in the project bin directory when I promote it to the webserver. I also need my local and the server web.config to be different. Before I started using this library I really enjoyed using the publish website feature of VS. Now it just seems to be getting in the way.
Answer: Regarding the web.config deployment problem: Scott Guthrie wrote about here:
Tip/Trick: Automating Dev, QA, Staging, and Production Web.Config Settings with VS 2005
You can easily automate the configuration process within the Visual Studio build environment (and do so in a way that works both within the IDE, as well as with command-line/automated builds).
Answer: Current configuration with the publish tool will send the web.config to the final site, and as far as I know there is no way around this.
Visual Studio 2010 is going to offer the ability to have targeted configurations allowing the deployment process to push out a different configuration.
As for the .dll reference, I believe the only way to get that to work is if you have "Copy Local" set to true on the reference.
Answer: It's not ideal - splattne's answer is the correct way to set things up - but you can move it out of you project file ('Exclude From Project') and just keep it in your solution ('Solution Items' in VS2010).
This was it won't be copied when you publish.
Answer: I found that making production Web.Config readonly on target server works fine when Publishing with Visual Studio 2010.
Hope this helps.


How to adjust the search in file behavior in spacemacs?

Question: Currently, when I using vim searching "/searchforsth" with "n" to search for words. After navigating through the words on this page, the next word that is not on the current page will appear at the bottom. But I am used to the behavior that this word will display on top or middle of this page, just like pressing "zt" or "zz". So I can see the following code of this searched pattern. Is there a way to define this behavior by myself? Thanks in advance.
Answer: You can achieve this by advising evil-ex-search as follows:
  (advice-add 'evil-ex-search :after #'recenter)


Sources of Mass in Special Relativity

Question: Let, we have an object with mass (previously called rest mass) m. It starts moving with a velocity v, and its relativistic mass (not a preferred term nowadays) or total energy becomes $m_{\mathrm{Rel}} = \gamma m$. This is the mass we get if we measure it on a scale. Now if we collide this object with another object having the same relativistic mass, assuming that no energy escapes, the combined rest mass of the new object would be $M = 2 \gamma m$ (Resnick/Special Relativity). Should we assume that the increase in mass is because of the temperature increase of the new body, meaning it is solely due to the kinetic energy of its particles? I guess the answer is no, some of the energy should be used as binding energy or other forms. How does special relativity explain those other energies, like binding energies? I mean, they simply have mass even though nothing is 'moving'.
Comment: Where the mass precisely comes from depends on the details of the system. Kinematics cannot tell you something like this. I also don't think $\gamma m$ is what a scale would see.
Answer: Suppose there is a binding energy. Maybe a proton and an electron collide to make a Hydrogen atom.
This means that these two objects decreased in potential energy by being bound together, and therefore there is surplus kinetic energy in the system. This kinetic energy of the constituents manifests as extra rest mass of the whole. So the mass is larger?
Well, sort of. Obviously, this energy was contained in the field, in this case the electromagnetic field. In fact, the Poynting vector of that Liénard-Wiechert potential must have been pointing forwards, so the field is apparently containing forward-flowing energy and one might expect this to not only be a mass term but even to be measurable—change the trajectory of the charged particle, and in addition to a wave propagated to infinity, any new field energy and momentum must have been transferred to the field by your process of changing that trajectory. So it seems very likely that this energy was already there, and was part of the measurement, but is now somewhat invisible?

Sources of Mass in Special Relativity


TeXworks linux vs windows

Question: I have some documents that require extensive use of BibTeX files, and on the windows version of TeXworks there is the possibility of running pdflateX+MakeIndex+BibTeX, which is not present in the linux version (I am using ubuntu). I have to separately run BibTeX and the LaTeX compilers so that I can update my citations, which is a bit of a hassle. Is there any way to manually add the pdflateX+MakeIndex+BibTeX mode to TeXworks under linux?
Comment: Since you have some responses below that seem to answer your question, please consider marking one of them as 'Accepted' by clicking on the tickmark below their vote count (see [How do you accept an answer?](http://meta.tex.stackexchange.com/q/1852)). This shows which answer helped you most, and it assigns reputation points to the author of the answer (and to you!). It's part of [this site's idea to identify good questions and answers through upvotes and acceptance of answers](http://tex.stackexchange.com/about).
Answer: create a little bash script for the three commands, put it into ~/bin/ and then create a new menu option inside TeXworks (Edit->Preferences).
Answer: MiKTeX on Windows includes a program called texify which does the combined pdfLaTeX, MakeIndex and BibTeX run. There is not an identical program on Linux, but there are several scripting systems for LaTeX. As Herbert has said, you could write a simple script to do the job, but if you are not a scripting person might want to look at for example latexmk (which just 'does stuff') or arara (which is more user-controlled).
Comment: `latexmk` is already installed in TeXWorks
Comment: @Herbert Depends on how you get TeXworks: the 'vanilla' one does not include it.
Comment: Ah ok, didn't know that
Comment: then just adding latexmk to the typesetting tools in teXworks should be enough for it to work?
Comment: @joaocandre: for TeXLive yes, it is already installed. You can test it with `which latexmk`

TeXworks linux vs windows


Which negative form is acceptable?

Question:
He has not to cook rice.
He does not have to cook rice.

Which negative form is acceptable?
Thanks in advance.
Answer: The second.  The helping verb "to do" is  one of the three main helping verbs.  It is the one used to give a negative answer and to ask a question where there is no other helping verb. Here, 'have to' is a modal auxilliary.  The main verb is "cook".
Answer: Your first example is ungrammatical. The second is valid.
Note that when you say that someone "has to do X", there are two kinds of negation possible: You could say that he is not required to do X, or you could say that he is required to not do X. That is, there are really three possibilities: You are required to do it; You are forbidden to do it; and, You can do it or not as you please.
So:

He has to cook rice.
He does not have to cook rice.
He must not cook rice. - or - He has to not cook rice.

Some object to "he has to not X" on the grounds that this breaks the rule against splitting an infinitive. Personally I think this is a pointless rule (in the same category with "never use a preposition to end a sentence with" that we make fun of often here), but a teacher or editor may believe in this rule and mark you off for breaking it.
Answer: "You have to do" is derived from "You have the duty/obligation etc to do sth". So "to have + to-infinitive" is a normal verb and the negation with don't is logical.

Which negative form is acceptable?


Do turbine engines contain engine oil and fire-extinguishing fluid?

Question: When aircraft turbine engine companies sell their engines to aircraft manufacturers, does the product contain the tank and pipe for engine oil and fire extinguishing fluid in the same package? Or is it something that the aircraft manufacturer has to build for the engine independently?
Answer: For turbofan engines used on passengers aircraft, oil system and fire sensor system are part of the engine. This is not the case for fire extinguishers which are manufactured by third parties and installed by aircraft and nacelle manufacturers at the proper locations. The nacelle is the aerodynamic engine housing with the inlet, fan duct and various systems.
In the picture below, showing a final assembly line of a GE factory, the black tank on the fan case is the oil tank:

Source
Oil tanks and pipes
They are part of the engine because they are deeply interlinked with other engine systems (bearing sumps, gearboxes). If you see a technician on the ground opening some panel on the engine during the aircraft turnaround, it's likely to check the oil level in the tank:

Top image, CFM56-7B engine: source.
Bottom image: CFM56-7B Component Identification Manual
Fire protection system
For fire protection includes the fire detection system and the fire extinction system. Detection, comprising temperature sensors (fire loops) embedded in the engine, is part of the engine. In the image below, #263 is a sensor loop around the HP turbine at the rear of the engine:

Image source: CFM56-7B Component Identification Manual
The fire extinction system is composed of gas bottles external to the engine, located in the main wheel wells or the fuselage.

Image source
The gas has been a halon until 1994 (production stopped to protect ozone) and is now a hydrofluorocarbon. The gaz is released from its bottle using a switch in the cockpit:

Halon bottles, Boeing 737 NG, source
The gas is then conveyed from the bottle to the engine by pipes running in the fuselage, the wing and the engine nacelle. There is at least one bottle for each engine, and there are other bottles for cargo holds and various protected locations.
Answer: Your question has been expertly answered in great detail.
Consider this: Engines of all types are made of metal parts that are spinning against each other. Metal spinning against metal will quickly result in the parts quickly welding themselves together and seizing if they are not separated and protected by a thin coat of oil.
Due to the protective lubricating properties of oil you can think of oil as being the "life-blood" of any engine.
Considering that, if an engine company were to produce and deliver an engine without an included oil system, they would essentially be assuring the engine's immediate destruction (or, at a minimum, counting on other engineers who were not involved in designing the engine to design and add an appropriate engine oil system).
It would mean that the engine manufacturer had not finished building the engine.
Comment: Then entire question has been expertly answered in great detail. I cannot match the current exhaustive explanation of the fire extinguishing system.
I was thinking that if the person who asked the question is brand new to engines, I would tell him a little about why the oil is so extremely important that ANY engine produced without an oiling system would be an incomplete unfinished engine that wasn't ready to be delivered to anyone- not even an aircraft manufacturer.
EDIT: Oh, I see that you are mins!  Your explanation is fantastic and exhaustive- complete with photos.  Great job!


Need to resize multiple image files

Question: Looking for recommendations for a free or open-source application that can batch resize multiple image files (.jpg)
Comment: Welcome to StackExchange, please have a look at [how to ask a good question](https://graphicdesign.stackexchange.com/help/how-to-ask) to help people give you the best answers possible.
Comment: What OS are you running?
Comment: This is just too broad, a google search would probably give you enough results.
Comment: Please [edit] your question to specify: 1) What's your OS? 2) What are your constraints? For example, do you want something with a GUI or a command-line tool? 3) Do you have any further requirements?
Answer: I thought this had been asked but didnt find it from my searches. You didn't specify an OS or specify if you were increasing or decreasing the file size. So here is a dump of some tools or apps I've used throughout the years.
A great utility to use is Imagemagick. It has convert and mogrify. Example with convert:
for image in *.jpg; do
    convert "$image" -resize 80% "${image/.jpg/-80%.jpg}"
done

If you're on a Mac and you dont want to script in the terminal you could use the built in Mac Preview:

Select all the images you want resized in the Finder, and then open them within the Preview app
From Preview, select all of the images that you want to batch resize from the left-side thumbnail drawer (Command+A will select them all)
Now, go to the menu labeled "Tools", and then choose "Adjust Size"
Enter a value for what you want the new width and height to be
Next, navigate to the 'File' menu and click "Save All" or, to save a NEW version that is resized, choose "Export Selected Images…" or "Save As"

Reference: Batch Resize Images on Mac with Preview. If you're looking for a paid app for Mac there is Image Resizer.
If you own or have Photoshop this can be achieved as an action:

Create a new custom Action
Go to File → Open an image
Hit the Action record/play button.
Crop to required size.
File → Export → Export As → JPG.
Hit OK.
Close image.
Hit Stop button on Actions panel.

reference: I need to batch resize 20 images.

Need to resize multiple image files


Long dashes between sentences

Question: In Ludwig Wittgenstein's writings, I often see long dashes (both em-dash, and one even longer, shown in red circles). I can sense (at least I believe I do—perhaps, from the writer's point of view, the two thoughts are tightly-connected, yet they have to be separate sentences) their function; but is there such a usage? Never seen any punctuation guide mentioning such a usage.
Comment: Irrespective of Wittgenstein's intentions, I sometimes feel the need in my own writings. Here's a hypothetical case: "In backgammon, simulations are used heavily, and often provide new insights.—What is the best move if you start with six-four? ..." Here, whether apparent or not, my intention is to make sure that the question is tightly connected with the preceding sentence.
Comment: @michael_timofeev I was going to add that option in my comment, but I was about to reach my character limit. I do not particularly enjoy a colon in the above example. The first sentence does not particularly hint that an explanation is coming. Anyhow, who is stop one from inventing his own style.
Comment: It looks like a stylistic choice. The longer dashes are _em dashes_ and the shorter one is an _en dash_.
Comment: This does not look like traditional uses for a dash...it seems to be more of stylistic choice to add pauses.  The dash is separating full sentences, almost taking the job of a period.
Comment: @Michael _timofeev:  But the periods are there also.  So Wittgenstein must have had some additional purpose than separating sentences.  Maybe he felt he needed a separation stronger than a period, but short of a paragraph break—a "sub-paragraph" as it were. This still doesn't explain why he used a two-em dash in one paragraph and three-em dashes in the other paragraph. For all we know, it might involve a typesetting error or improvisation (e.g., perhaps the typesetter had only two three-em dashes in his case, and so couldn't set three of them on the same page.)
Comment: @BrianHitchcock I dunno.  It doesn't make sense to me.  Maybe they're ...[fill in the blank with a theory]
Comment: @BrianHitchcock this doesn't look like it was scanned from a book...maybe text from the Internet?
Comment: @michael_timofeev It is from the retail e-book.
Comment: @blackened well a dash isn't the way to go, especially after the period.  I would join the two sentences with a colon.  There's a very good book on punctuation, The Art of Styling Sentences by Ann Longknife.  Has been in print since 1972.
Comment: @Adam: in this case, the em dashes are the shorter ones. The longer ones are two-em dashes. And there are no en dashes at all in the snippet presented.
Answer: Understand that not too long ago everyone wrote stuff out in longhand.  Certainly no computers, and, even if they existed, typewriters were reserved for use by secretaries and typists.
In longhand it's easy to develop a (personal) style (perhaps varying from one document to the next, or even within a document) where you use dashes of varying length to set aside parenthetical text, emphasize certain phrases, separate lines in a poem, indicate an elision, etc.  Since the length of the dash is purely a matter of how far the pen moves on the paper, there is no motivation to standardize this, other than what ones headmaster may pound into ones head in school.
And pity the poor typesetter who must read the longhand scrawl and attempt to interpret its meaning.  Typesetters would attempt to understand the intent of the markings and "standardize" it to some extent, but they could only do so much, especially when the author was fond of long, convoluted sentences.
So you are left to attempt to understand the markings yourself, perhaps based on "standard" usage, or perhaps throwing that out the window and developing a new interpretation.
Answer: dashes are used for some dashing(unusual, interrupt) information inside a sentence. However, it is a big one, and possibly,  it may be used for a dashing information inside a paragraph-- i am not sure. (here i use dash)
dashing here i am using for unusual, interrupt; dashing for dashes is just memory trick for me.
Comment: You certainly dashed my brain.
Comment: @blackened - So did he dash any hope of increasing his reputation?

Long dashes between sentences


Performance hit having SELinux on high traffic Apache?

Question: I want to start using SELinux, and was wondering what kind of performance hit I should expect to see on a webserver with high Apache traffic?
<1%, 5%, 10% ? What range are we talking about?
Answer: SELinux Unofficial FAQ says 7%. In my experience I cannot tell the difference whether it's on or it's off (it used to be easy because with it on nothing worked!) but I'd not be surprised if it's much less than 7% that as there are lots of mentions of performance improvements on the release notes   In RHEL5 the annoying things have gone away and the feedback from setroubleshoot and the audit logs is really  good.
I'd suggest you come up with some kind of benchmark maybe using JMEter/Selenium to replay tests against your webserver in a lab where you can test against an SE enabled and a disabled machine.A Usenix Paper discussing a benchmark on SELinux is interesting and might provide a good start.  It might be that one a webserver, once all the caches are warmed up then the overhead is very small.
Let us know what your results are.
Comment: Thank you very much. ~7% can I live with. As the hacker of the Xbox 1 said: "There isn't any compromise between speed and security. Either the system secure or not." =)
Answer: I agree with davey's answer of approximately 7%. I would post this as a comment but I don't have enough karma.
However, do keep in mind that the three modes of SELinux: disabled, permissive, and enforcing. There is no speed difference between permissive and enforcing.


Bending light to create holograms

Question: In my modern fantasy story, magic users are shown creating 3-dimensional light structures or holograms by bending the light source from a flashlight to create a holographic images such as animals and models. Would this theoretically be possible using pseudo-science while still keeping suspension of disbelief?
Comment: You said the magic word (ambiguity intended). "Magic" is shorthand for "To the best of my knowledge, that thing that just happened, ought to have been impossible". Well we do lots of stuff that is "magic" to 9 out of 10 of our forebears (the total amount of humans that have every lived is approximately 100 billion individuals), or 99.9% of the time humanity has existed (100 000+ years).  So if you have then just postulated that the **seemingly impossible** is possible in your story... well... there you are then.
Comment: It's **magic**, only available to magic users - why do you need pseudo-science as well?
Answer: SMH, once you throw magic into this the answer is always yes
Physically light cannot be bent (its path can be distorted by gravity). So sure if you say your magic is bending light than by all means it is reasonable.
Answer: Light can be bent with mirrors and lenses. You can create effect like this by using different mediums with different refraction properties such as glass. You might be able to use a system that uses a manipulated magnetic field can alter specialized charged particles of some glass-like material. The end affect would be a "glass sculpture" that changes over time as the field changes, which could potentially be possible. Such a device isn't possible today because we don't have the power to manipulate magnetic fields this well but may be in the future. The glass like substance doesn't even have to be solid which would make for something similar to 3D holograms.
Another idea would be to program people's vision directly. This would involve sending data directly to people's optical system. Pretty much a HUD for everyone and this can allow for additional information. Today this can only happen with a screen in front of their eyes and a headset like Hololens. In the future, we might be able to implant a chip that can alter your optic nerve directly to allow for additional images to be added.
Answer: To you, what is the difference between "creating holographic images" and simply bending/absorbing light in the exact way a real object was? The latter may be easier.  Rather than doing all of the tremendously complicated interference games required for holography, simply bend light right where the surface of the animal's skin would be, and bend it exactly the same way it would have been reflected off the real skin.
Basically, what you'd be doing is raycasting a 3d model of the animal, in real time.
Comment: Both playing with interference and bending light the way real object would reflect it is ultimately about creating the same wavefront. Why one should be easier than other? I got 5 (equivalent of usa A grade) in synthetic holography class and I believe creating small interference structures should be easier than large real size ones. It was with technology, at least.
Comment: @Mołot Making real objects lets you take advantage of locality.  The information about any one point in a hologram is spread across the entire hologram.  The information about one point in space is stored in one point in space.  Since you took a class on it: can we make real-time moving holograms yet?  When I last researched the topic, the calculations to create such a hologram were far too slow.
Comment: in theory it should be possible now, with single color holography and relatively low resolution. Years ago calculating one frame, three planes on an old cpu (would be, like, dozen years old now) took about 10s. About locality, you need the same amount of information, one wavefront. It's only a matter of how it's stored. And with holography you can create only the part of wavefront that's actually going to hit someone's eyes. So less information needed, total, and less work with light, even if more complicated. But these holograms are kinda magic anyway, aren't they?

Bending light to create holograms


What's the difference between DataProvider and Factory in TestNG?

Question: When to use DataProvider and when to use Factory ?
Answer: TestNG factory is used to create instances of test classes dynamically. This is useful if you want to run the test class any no of times. For example, if you have a test to login into a site and you want to run this test multiple times,then its easy to use TestNG factory where you create multiple instances of test class and run the tests.
public class WebTestFactory {
  //createInstances method will create 10 objects of WebTest class
  @Factory
  public Object[] createInstances() {
   Object[] result = new Object[10];
   for (int i = 0; i < 10; i++) {
      result[i] = new WebTest(i);
    }
    return result;
  }

and the test class is now:
public class WebTest {
  private int m_numberOfTimes;
  public WebTest(int numberOfTimes) {
    m_numberOfTimes = numberOfTimes;
  }

  @Test
  public void testServer() {
   //Code to test the application
  }
}

Your testng.xml only needs to reference the class that contains the factory method, since the test instances themselves will be created at runtime:
<class name="WebTestFactory" />

The factory method can receive parameters just like @Test and @Before/After and it must return Object[].  The objects returned can be of any class (not necessarily the same class as the factory class).
Whereas, dataprovider is used to provide parameters to a test. If you provide dataprovider to a test, the test will be run taking different sets of value each time. This is useful for a scenario like where you want to login into a site with different sets of username and password each time.
public class DataProviderTest {

    @Test(dataProvider= "data")
    public void TestUltimatixFromExcelData(String userName,String password) {
        WebDriver driver;
        driver=new FirefoxDriver();
        //Test to login into a site
    }

    @DataProvider(name="data")
    public static Object[][] dataProviderTest() throws Exception{

        Object[][] returnArray={new Object[]{"username1","password1"},new Object[]{"username2","password2"},new Object[]{"username3","password3"}
        };
        return returnArray;
    }

}

Comment: A dataProvider can also be put on the test class constructor.
Comment: +1 Good Explanation. @why : Please accept this if you get sufficient information.
Comment: Why not create the WebDriver instance in the DataProvider and pass that along also?
Answer: Data provider  always create the same data set. So if you need Person instance you will always get person called John Wayne from data provider.  They provide static data. This is good for test parametrization when you supply your test with two objects - first is method input, second that you expect.
Factories allow you to create tests dynamically.. They provide dynamic data like random content or if you want call some method with diffrend parameters.
Comment: What would be your approch, ich you have your testdata in different files (not testng files) and you've a method that is using these datas. Would you rater use a factory or dataprovider ?
Comment: Difference is in method of supply data to your method. As you can see in example, link in post, when use xml to pass params then you get data provider - data came from config implementation is feature of TestNg. When build class to create data dynamically then you get Factory.
Answer: Factory implementation executes the test method for each individual instance of the test class. Where as DataProvider executes the test method for a single instance of the test class.
Answer: TLDR:

@DataProvider -> params for a SINGLE method
@Factory -> params for ALL methods in a Class

Let me start with using DataProviders:
public class VeryImportantTest {

    @DataProvider
    public static Object[][] numberProvider() {
        return new Object[][]{
                {1},
                {2}
        };
    }

    // DataProvider provides data to a SINGLE method
    @Test(dataProvider = "numberProvider")
    public void test1(int num){
        Assert.assertNotEquals(3, num);
    }

    @Test(dataProvider = "numberProvider")
    public void test2(int num){
        // ...
    }

    @Test(dataProvider = "numberProvider")
    public void test3(int num){
        // ...
    }

    // Hmmm... I still have 10 tests to write here,
    // and it's getting annoying to specify the dataprovider everytime...
}

But not with the @Factory:
public class FactoryExample {

    @Factory
    public Object[] factoryMethod() {
        return new Object[] {
                new FactoryExample(0),
                new FactoryExample(1)
       };
    }

    private int number;

    private FactoryExample(){}

    private FactoryExample(int number) {
        this.number = number;
    }

    // Now there's no need to specify dataproviders everywhere, nice
    @Test
    public void test1(){
        Assert.assertNotEquals(3, number);
    }

    @Test
    public void test2(){ // <-- No need to specify params in each method either
       // ...
    }
}

DO note two things when using Factory:
1) You have to specify a no-arg constructor or make fields + methods static. See more here
2) With @DataProvider, your @BeforeClass will be executed once. With @Factory it will be executed with every iteration.


How can I use torrent using psiphon

Question: In my college, I have a proxy server. Now using psiphon, I can bypass proxy. But problem is, torrent is not working with psiphon. If I am using my cyber roam account, also torrent does not work. Is there any solution for the problem? Thank you.
Answer: I have found a way to run torrents on Psiphon, you would also be able to play online games like League of Legends and DoTA.
Here is how it is done:

Download Psiphon. Connect to the server closest to you.

Go to settings.
In settings, go to "Local Proxy Ports".
Enter a desired port number (say 443) in the HTTP/HTTPS section.
Apply the settings and reconnect.

Download OpenVPN for windows/linux from here.

Right click on the OpenVPN GUI running in the taskbar and go to Settings.
Go to Proxy tab.
Choose Manual Configuration. And choose HTTP Proxy.
Enter the address: 127.0.0.1 and Port:443 (which you noted earlier).
Click OK.

Here we made OpenVPN to connect to the server through Psiphon.

There are a lot of free OpenVPN providers which you could find online. Choose any one of then and download the .ovpn config file and place it in "C:\Program Files\OpenVPN\config"
Connect to the server using OpenVPN client running in the Taskbar.
That's it you can play online games and download torrents.

EDIT: Found an easier way
Now we don't need Psiphon to connect to internet. I have partially figured out how Psiphon works.
Basically, all it does is establish a VPN through the UDP port 53.
Here is how you should make it work:

Google for UDP port 53 OpenVPN servers.
Download the .ovpn config for the server which you are going to choose.
In OpenVPN GUI:

Right click on the OpenVPN GUI running in the taskbar and go to Settings.
Go to Proxy tab.
Select "Use OpenVPN config file settings". The previous settings will fade away, nothing to worry about it.

Make sure that Psiphon is not running.
Connect to the server using OpenVPN client running in the Taskbar.
This time it may take a few seconds more compared to the previous method.
That's it you can play online games and download torrents.
Comment: Welcome. We like any good answer, no matter how late!
Comment: I have been graduated from college. I don't use psiphon anymore. Hope it answers the problem.
Comment: I have found a way where even Psiphon is not needed for torrents. Gonna make a few edits now
Answer: Most likely, you cannot. Here a blogger claims to have spoken with a representative from psiphon, who says:

The VPN mode has its bandwidth deliberately restricted, as Psiphon is keen to be all about censorship evasion , and not about downloading movies.

So, even if you use their VPN, your download rate will be painfully slow, read the blog post above.
Your best solution is to run an OpenVPN server at home or on a cheap VPS (there are some for as little as 2 or three bucks a month), on TCP port 443, which is not blocked by just about all proxies and firewalls.
Comment: A lot of work is done with torrent. What if I will not download movies using torrent. :D
Comment: Please guide me to  "run an OpenVPN server at home".
Comment: @learner At home, what's your OS? Windows, Mac, Linux?
Comment: @learner If your OS is Windows, a good guide is https://community.openvpn.net/openvpn/wiki/Easy_Windows_Guide If there is something which you cannot solve, please ask a new question.
Comment: In some countries with limited Internet access (such as Iran), ordinary websites such as Youtube and Facebook (and lots of other online services) are censored. These services are full of video content.
Answer: Tribler is better suited to what you have in mind. Its basically a cheap but effective (if not slow) proxy run client. It uses the darkweb to tunnel all torrent traffic. Some say its best to use it with a VPN, but it works just fine on its own. Oh and it has its own built in search engine as well a bonus? Dunno its not the best. You could use Tor for torrent files if paranoid. That or just use i2p with Vuze which has a plugin for i2p, so not only do you tunnel torrent traffic that way. You also make yourself practically invisible and encrypted. No I won't tell you how to do it :)

How can I use torrent using psiphon


The Buzzer Game

Question: Two players, A and B, are each given air horns. Also present is a device which will at some random point produce a noise. If the device produces a noise before either player, they die. If both players produce a noise before the device, the first to produce the noise is killed and the second one lives. If only one player produces a noise and the device sounds before the other player gets a chance, the player unable to produce a sound is killed. Is it necessarily so that if they are perfectly logical and selfish beings, they both shall die?
Comment: I remember seeing this situation in the Book of Questions, except it was you and a significant other, and it was a moral decision rather than a game-theoretical one.
Answer: Since there is a random element, logic would seem to fall out of the equation. They are both going to try to survive, which means blowing their horn as soon as the other person blows theirs or blowing it right before the device sounds. Since human reaction time is quite fast, the odds of guessing when the device will sound accurately enough that the other person doesn't have time to respond are very low. So, then, the best bet is to wait for the other person to blow their horn, right? The hitch is, they are both perfectly logical so they know that the other one has come to the same conclusion. Then they will both know that waiting for the other to blow is certain death for all, so they will either blow their horns randomly or try to trick the other person into blowing their horn. In a situation like this, tension would be very high, and making a sudden movement might be enough to get the other person to blow first out of overactive reflexes. Assuming that they are not exactly the same person, despite being perfectly logical and selfish, one may succeed in tricking the other into blowing, or one may blow first in hopes that they are blowing just before the device goes off.
They don't necessarily both have to die.
Answer: By the given parameters, A and B are both logical and selfish. Logically, there is no single-sided solution guaranteeing a logician's own survival - sounding the horn immediately has the same deadly effect as waiting indefinitely for the other logician's horn. The 'selfish' parameter is therefore disregarded as (logically) a 'don't care' condition. The remaining thing to consider is the survival of at least one of the logicians (in this case, the other logician), which each can effect by sounding their own horn first.
Both logicians follow the above logic and immediately sound their own horns. The possibility of survival arises when the killing device does not sound in less time than the logicians are physically capable of sounding their own horns.
Assuming identical reaction times, speed of thought, etc, the immediate simultaneous sounding by A and B means that none of the deadly conditions comes into play, so both logicians survive. If that assumption doesn't hold, then the slower logician survives.
Comment: I see what you mean by saying that selfishness is thrown out by the inability of logic to save oneself, but I don't think that it would lead to immediate altruism. As long as there was still a chance at survival, I believe the selfish logicians would still pursue it. Although, sounding one's horn immediately might still be the best course of action to maximize your odds of not getting killed by the device.
Comment: @Warkgnall It isn't that there is a slim but elusive chance of survival: without being able to control the other party, there is no strategy that leads to *any* chance of (their own) survival. It is arguable that being able to predict the other party's actions can be another lever, but that leads to the same solution: immediately sound the horn. Even there, 'immediate' is impossible to rely on due to those tiny random variations between A and B. So, strangely enough, the only chance of survival arises from a motivation of self-sacrifice in this set up.
Comment: I like this answer best, however it does assume a reflexion time set before the start of the 'game' for each logician to arrive to this conclusion. If they do have that time, it seems to be as it being a given that both will immediatly sound their horn instantly at the start of the game, as it is the scenario with the most survival rate by a clear margin (being one or both of them)
Comment: Thanks @Spacemonkey. You can avoid the reflection time by either assuming A & B are identical (same time to come to the same conclusion), or just default to the slower one having a chance to live. In either case, the possibility of living arises when the device doesn't sound before A & B.
Answer: Solving such questions is easy using the method given here.
The three strategies given to the players to choose from are as follows:
1: Never horn
2: Horn immediately
3: Horn after the other player
The payoff-table looks as follows (1 means life, 0 means death):
<code>              A adopts 1      A adopts 2       A adopts 3
B adopts 1      0,0               1,0             0,0
B adopts 2      0,1             1/2,1/2           1,0
B adopts 3      0,0               0,1             0,0
</code>
The only Nash Equilibrium is when one player chooses 2 and the other chooses 3. Meaning that immediately horning, or horning after the other player are both equally good strategies. Hence they will randomly select strategy 2 or 3.
Answer: It depends on what happens if they're indifferent. Assuming symmetry is broken somehow (because if it isn't, then they trivially both die), then one person will sound their airhorn first. Then, the second person will die either way, but they get to choose if the first one lives. The question doesn't say anything about what will happen then.
Comment: sorry about the confusion, i fixed it
Comment: @elriddler73: This is the answer to the updated version.
Answer: Firstly, the question did not resolve the situation when one player sounds the horn during the time the device is sounding. Does that player die from being the first person to sound the airhorn, or not die (while the other dies) because he "produced a noise and the device sounds before the other player gets a chance"? If he doesn't die, we have a loophole.
Secondly, the question does not specify if they are in the same room, and if they are, whether the device itself is present in the same room. If they are in separate rooms and cannot see the device directly, we note the question does not specify if the players have heard what the device sounds like before (and when it does, where the sound comes from). Then similar to Warknall's answer, they can try tricking each other that by making it sound like the device has sounded.
If they are in the same room, the question does not specify what qualifies as a "player making a noise" means. I think the intended answer to this is making a sound from their respective assigned airhorns (otherwise they would have a hilariously silent tickle war). If so, then the logical thing to do is to grab the other player's horn and sound it as soon as possible. Alternatively, they can cooperate and try to destroy the device together, but I doubt that is an option within the framework of the question.
Answer:
 It is not necessary that both die. As both are perfectly logical both know that waiting for the other to make a noise will kill them both. Therefore both can agree to adapt the rules to make one of them survive, assuming equal chances for both.One possibility is to prevent that both players can hear each others noise. For example by putting on headphones with loud music. Of course they both will make sure the other can't cheat, by checking the headphones before.
Comment: Putting a headphone on might actually kill them both.  They will, after knowing the other cannot judge by the ears, tries trick each other by acting it, resulting in fails to blow before the device buzz.
Comment: @Alex The question asks if it is **sure** that **both** die. I tried to show that this is not the case.
Answer: The Devil's Advocate's Answer:
No, it is not necessarily so. Many of the most logical people to have lived have believed in an afterlife. Someone could believe that sacrifices made in this life, especially an apparently altruistic act such as this, will be met with rewards in another. One could regard this sacrifice also as an act of selfishness, since they do it with the expectation of future reward or to confirm their sense of moral superiority. If they value these things above their own life, it is logical and selfish to sound one's own horn.
Alternatively, if the death from not sounding a horn is grim and painful, one might consider sounding the horn if that death promises to be instant or painless.

The Buzzer Game


POSER - Can Poser files be used in Blender and Blender in Poser?

Question: I only know Poser (now by Smith Micro) and use it for 3D stills.  Poser human characters/figures (with wireframes made by SmithMicro, DAZ3D or HiveWire) with photo-human textures can be extremely realistic, better than any other 3D programs I've seen.  I wish I could try my Poser figures in Blender to try its renderer, lighting, clothing creation, landscape creation, etc.
I don't yet know Blender; do any of you use Poser and Blender??
Thanks for your time!
Answer: Daz studio uses poser models and according to this answer exporting the model using collada (.dae) works, .fbx may also be a good option. You could export a posed character with .obj but that doesn't include the armature.
While each renderer can use the same image textures, expect some manual texture creating to use cycles, which is blender's newer and better render engine. You will probably find this much easier with the new principled shader in the new blender version about to be released. You can test it in the daily builds and see it in use in this tutorial
I would suggest asking/looking at poser specific sites like the daz3d forums which is where I first heard about blender years ago, people using it to make poser models.


Could Planck scale wormholes be a solution for non-locality?

Question: When two entangled particles are separated, an observation made on one particle seems to be able to act at a distance to determine the state of the other particle.  Is it possible, or has anyone in the field considered the possibility that entangled particles are connected by Planck scale wormholes so that the action is not really occurring over a distance and violating locality or speed of signal limits?
Comment: https://physics.stackexchange.com/questions/264586/communication-via-teleportation-entanglement-ftl-communication/264642#264642
Answer: I do not know much about GR, but I do not think the wormhole explanation is likely to find many backers in the quantum comunity.*
There are several reasons for this. The most important two are probably:
(1) Even with entangled particles that violate a Bell inequality (demonstrating the nonlocal interaction) their is no signalling. This means that the relationship between the particles is in some sense stronger than a classical sense of correlation, but is still weaker that communication. A wormhole or a faster-than-light signal would both, in themselves, enable communication, so you need to introduce an explanation/mechanism that limits the effect of the wormhole to only enabling nonlocality, not the stronger effect of actual communication.
(2) When two particles are in a shared superposition they are entangled and we introduce the wormhole idea. However, it is fully possible to have a particle that is in a superposition of two positions (say a photon is divided by a 50/50 beam splitter). We can describe this situation as two locations that are entangled with one another: either location 1 has a photon and location 2 is in vacuum, or vice versa. We have an entangled state of the two. Here the wormhole explanation starts to look weird, as we have a wormhole connecting a location to another location, just because a single photon could be at either of them.
We can make it weirder still by having a pyramid of beam splitters, so that the photon is divided between hundreds,  thousands or trillions of different modes. We now have just one photon, but trillions of wormholes are needed to connect it to all the places it could be. In fact its worse! I assumed an integer number of modes, but if space is continuous you need a continuum of wormholes for each particle!
* It has been looked at at least once though: https://doi.org/10.1002/prop.201300020
Comment: I agree with you....Frankly speaking it seems to me that  introducing wormholes to ``explain" non locality of the entangled states  actually introduces more issues than the ones it intends to explain.


Deleting multiple polygons at once in ArcGIS 10.1?

Question: I have a cloud mask shapefile that accidentally identified buildings as clouds.  I want to delete this mass of polygons in Arcmap 10.1 by highlighting all of them and pressing delete.  Then re-saving the shapefile.  Right now I can only highlight one at a time through clicking and pressing delete.  It is taking a long time.  Is there some settings I need to change?
Answer: Try changing the selection mode in ArcMap to Add To Current Selection.  Then you can select multiple features.  See the link here for a discussion:
http://resources.arcgis.com/en/help/main/10.1/index.html#//00s50000000w000000
Answer: To select multiple features in ArcGIS 10.1 you can open up the feature layer's attributes and choose select by attribute. This will allow you to filter the selection by using certain fields to mark the features to be deleted. Along with that you can invert selection if you are able to easily select all of the features that you want to keep and then switch it to the ones that you want to delete. Both of those buttons can be found at the top of the Attribute Table window.


Effervescent in mineral spirits?

Question: I'm shooting video of paint moving in mineral spirits.  To make for a little more action, is there a household granular/solid I could add to the mineral spirits that would gently effervesce ala alka-seltzer in water?
Comment: Are you looking for something that will effervesce in water or mineral spirits?
Comment: Something that would effervesce in mineral spirits.
Answer: A fish-tank bubbler with needle valve or regulator would not only provide bubbles but be controllable and would not need to be replenished, as would chemicals.
N.B. However you make bubbles in mineral spirits, it would help the highly-flammable liquid to evaporate, creating a potential explosion and fire hazard. You might get better images with less-miscible mineral or silicone oil, with less danger.
Comment: Thanks for the reply.  My thought is that a bubbler uses puffs, so it would mess with the effect, and the scale of what I'm doing is very small, a petri dish of spirits, so no hazard ;)
Comment: Those using motors do make noticeable puffs, but the vibrator type, especially through a fine stone, tend to make streams... which still might not meet your needs. Dry ice might work, if you could insulate it so that it doesn't sublime too rapidly.

Effervescent in mineral spirits?


Can the relay I connect to expose me?

Question: The way I understand Tor is that the "client" (say me) connects to a relay, and that relay is the only computer they connect to from then on. If that is the case, why can't a hostile relay simply run three copies of Tor modified to connect to each other, and thereby identifying me and what I am connecting to?
Answer: Good question.
Don't take this as a definite answer until someone can confirm it, as I am not sure if any of these points are correct, this is all from dodgy memory
I believe that the tor client chooses all three relays it will eventually connect to.
Tor connects to the first relay, and sends a build command to it to build to a specified second relay.
The client encrypts a message to the second relays public key containing a session key for the second relay to communicate back.
The second relay replies, encrypted with the session key.
The same then happens with the third relay.
If a modded first relay tried to connect you to another second relay, it would not be able to decrypt the session key, and so wouldn't be able to communicate with the client, so the whole thing would break down.
Comment: The public key should be obtained the same way you get the ip of the relay, from a public list
Comment: So how does the client get the keys for the second and third relays? If it's through the first one then there's the same problem.
Answer: I agree with puser on circuit construction. However, I believe the public keys are obtained from the directory authorities and then placed locally on your device in the $tor_datadir/cached-descriptors file

Can the relay I connect to expose me?


Why wasn't the DeLorean DMC-12 popular on the market?

Question: The DMC-12 seemed to be more convenient for parking because of its doors. It has no paint, instead just stainless steel, so you shouldn't worry about scratches. Why such brilliant car had no success ?
Comment: If I get a chance I'll try to make a proper researched answer. From my memory, it was expensive as hell, and the automaker was independent, so they had to build themselves a dealership network from scratch. I have a vague memory of the owner getting 80's-ed in some way too.
Comment: The stainless steel was dull grey outside a showroom. The gull doors were weird, and as TED said you couldn't find one if you wanted one.
Comment: wikipedia says it was a victim of the market slump of the mid '80s. Combine an economic downturn with an expensive niche product and no other source of corporate income and you're in trouble. Add rumours about the company owner being involved in organised crime (drugs trafficking) and you're dead.
Comment: I would posit that it was not that it was _unpopular_ in the market, it was not _in_ the market. It never made it to the point where there were enough being produced to overcome the shortcomings. There were other cars throughout history, which were considered ... _problematic_ (i.e. Pinto, AMC's Pacer) that were (or should have been) market bombs, yet were made in enough quantity to be profitable anyway.
Comment: The joke around here was that they didn't sell well because everyone was afraid of [cocaine residue](https://en.wikipedia.org/wiki/John_DeLorean#Arrest_and_trial), but I think that has the cause and effect reversed.  It certainly didn't help dig them out of receivership though.
Comment: Fabrication with stainless steel requires more specialised welding skills which increases the cost of production. Also, unpainted metal needs to be polished to make it look nice. If it gets too badly scratched, re-polishing the metal can be expensive.
Comment: The real problem was that the "brilliant car" simply wasn't brilliant. It was an expensive sports car without expensive sports car performance (both underpowered and overweight). The unique features such as the doors and the unpainted bodywork were simply gimmicks and production shortcuts, whose shortcomings were quickly found by the car's unfortunate owners.
Comment: @Steve Bird how those doors can be a shortcut, why they are not convenient ?
Comment: @Oldcat And there was a problem with that the doors leaked water. And as Steve Bird wrote it was underpowered. It was originally intended to have a V8, but instead got the PRV V6.
Answer: Actually there was a waiting list for the DeLorean.
It was a good car! But design, production as well as the company owner were dogged by setbacks, in part caused by the innovative design and therefore untested manufacturing technologies used.
Engine selection and location as well as chassis construction were changed after the original concept which led to considerable schedule pressures.
Construction on the factory began in October 1978, and although production of the DMC-12 was scheduled to start in 1979, engineering problems and budget overruns delayed production until early 1981.
About 9,200 DMC-12s were produced between January 1981 and December 1982. Almost a fifth of these were produced in October 1981. The workers were largely inexperienced, but were paid premium wages and supplied with the best equipment available. Most quality issues were solved by 1982.
The DeLorean Motor Company went bankrupt in late 1982 following John DeLorean's arrest in October of that year on drug trafficking charges. He was later found not guilty, but it was too late for the DMC-12 to remain in production
In 2007, about 6,500 DeLorean Motor cars were believed still to exist.
Reference:
https://en.wikipedia.org/wiki/DeLorean_DMC-12
Comment: This does not answer the question.  The car may have been in high demand *briefly* but it was quickly pulled - surely if it was really such a great product the company could have gotten financing to keep it going until the factory ramped up.  Why did production end after just a few thousand sales?
Comment: @JonofAllTrades like with all small companies with a single person in charge, if that person falls away the company fails. DeLorean was arrested, put in jail awaiting trial, so the bills couldn't be paid given that he was the only one with access to the bank accounts. Also, the negative name the company got from being associated/owned by a suspected criminal no doubt led to some orders being cancelled and sales dropping.
Comment: @jwenting: that makes sense. Why don't you write it up as an answer?
Comment: I feel I must comment that this is explicitly a repost of Wikipedia, which is EXACTLY why we close questions using the trivia reason. If this is the answer to the question, the question should be closed.


My Armature rig slows Blender down

Question: When selecting small groups of bones in Edit Mode it runs fine, but using Pose Mode and trying to move a part of my character or trying to move the rig or character in Object Mode it lags the program a lot. I used the Rigify add-on to add in a Human metarig and the lag arose when I parented it to my character.
Comment: Sadly, that is probably just an artifact of the computer figuring out how to deform the model, when you select/move the bone.
Answer: I fixed the issue. It lagged because my model had WAY too many tris. I heavily lowered the tris, restoring the original speed.
Comment: This is one of the reason why you should retopologize your models before rigging them. Another reason is that you cannot predict how a triangulated mesh deforms when you pose it. You probably get lots of ugly rendering artefacts in those areas.

My Armature rig slows Blender down


How can I move "AMAZON PAY" button from shipping address to Payment Methods In one step checkout magento2

Question: I want amazon pay button inside my payment method block where all the payments shows, How can i do that is anyone have an idea ???
Answer: Try below steps and you get your result.
<code>1) Go to stores->Configuration->Sales->Payment methods.

2) Go to Amazon Pay -> Advanced -> Frontend

3) Now change the dropdown(Show Amazon Pay in payment methods) value No to Yes.

4) Now Click on save config and you get result you want.
</code>


Report Server pointing to another Reporting Server

Question: I am trying to configure a public facing Reporting Server, which is actually talking to a private Reporting Server backend.  I have established the connections between the two of them, but I cannot get access to the reports because it keeps asking me for a Windows User when I try to connect to the Public facing website.  Is there anyway that I can stop this from happening?
Answer: It seems that you have the reporting server (MSSQL ) to windows authentication and for some reason you might have some ports closed . Please see the guide bellow for ports http://msdn.microsoft.com/en-us/library/cc646023.aspx used by MSSQL (in general ) and guide Reporting server security (http://msdn.microsoft.com/en-us/library/bb522728.aspx) .
Comment: I'll give this a go


Answered poor quality question (probable duplicate) in a comment. What to do?

Question: I found this question: https://stackoverflow.com/questions/42932596/how-do-i-add-a-number-to-pandas-dataframe-index?noredirect=1#comment72966754_42932596 that I find low quality, as it is not clear what the OP is asking and does not provide a MCV example. I flagged this as a duplicate, the OP didn't accept it as he didn't get how to adapt the duplicate to his specific case, so I suggested him what to do and he solved the problem.
Should I write an answer or wait for the question to be flagged as duplicate?
Comment: If you flagged the question as a duplicate, and you believe the answer to the duplicate question answers the question, then you shouldn't submit another answer.  Unless you have a new approach that has not been covered by the duplicate answer.
Comment: Looks like they don't actually have a different question, they just had a simple typo in their solution.  Leave it as a duplicate.
Answer: This example illustrates why answering in comments is the worst possible solution to these problems.
Look at this post.
We have a down-voted question which may or may not be a duplicate (probably not), but the question seems "answered" to just about anybody looking on — in a comment — which I guess maybe helped the author maybe, but that's about it and they're gone; case closed.
But unfortunately for everyone else, comments have none of the assurance capabilities that properly vet what's been said (like proper voting and the wiki-style editing that allow us to improve that information), assuming it's correct.
I'm not picking on you specifically; but so may people feel it's justified to answer a question in comments if the post is off topic… or if they simply don't have time to work up a proper response… or if they just want to guess or post a half-baked answer that maybe someone will elaborate on later, maybe.
It's easy to see in this example why allowing folks to answer in comments essentially "breaks" the Stack Exchange model. These comments should be flagged and removed on sight to allow the process to play out as intended by this Q&A framework. Otherwise, what is the value having this Q&A format in the first place?  </soapbox>


What type of interpolation should be used in key rate perturbation models?

Question: When perturbing a key rate in order to assess sensitivity of portfolio value, what sort of interpolation is standard? A book I am looking at says linear, but this seems pretty unrealistic to me--and of real significance for longer durated portfolios or shorter term perturbations. Anyone familiar with literature on the matter? Thanks.
Comment: Please add a link or a reference.
Answer: If I have understand right what you are looking for, I think that Nelson–Siegel Model can halp you, google it.
Hear some readng: Nelson-Siegel model


What is the amplitude( or intensity) of an electron wave in an atom?

Question: In Bohrs calculation for finding the radius of orbit of electron, we have used the concept of particle nature of electron (for quantization). But no information is available for the amplitude of such electron wave.
  what if the amplitude is greater than the actual radius of the orbit and the electron thus touches the nucleus?.
Answer: You aren't supposed to try to imagine the wave in Bohr's model. This model was a first attempt at creating a somehow-working model of a stable atom. Bohr's model is now superseded by quantum mechanics, which has much more sense in its definition of the wave function.
Quantum mechanical wave function doesn't represent a wave on a membrane around the nucleus or anything like that. It's more similar to electromagnetic wave: merely a function defined for all space and time. Square of absolute value of the amplitude of quantum-mechanical wave function defines probability of finding the electron in the given point as per Born rule.


What is the configuration file read by init process in fedora 18?

Question: Just i want to check the configuration file used by init process in fedora 18 (32 bit). In older versions it is mentioned as /etc/inittab. Actually i found the file but i didn't get any info regarding configuration. it is saying that "inittab is no longer used when using systemd". If it is not the configuration file used by init process please mention the path where it is
Answer: Yes as systemd is being used for setting runlevels and booting configuration you can check the configuration files in /etc/systemd/system/ directory where you find some target files for the different runlevels like graphical.target for runlevel 5.
Thanks & Regards,
Alok Thaker


Identifying windings of a single phase induction motor

Question: How can I identify the main and auxiliary windings of a single phase induction motor which has only three terminals (1.Red, 2. Yellow & 3. Black) out of the device? How to connect capacitor and power supply to it?
Comment: How do you know it is what you think it is?
Comment: Also, how would you know the correct value capacitor should it be what you think it is?
Answer: Tricky solution:
Measure the winding resistances. Auxiliary windings are often thinner and therefore have a higher resistance (even if it's just a little bit higher).
Once you know which terminals are used for each of the two windings, you
can connect them to the power supply and the capacitor as shown in the following picture:

The picture was taken from the book "R. Fischer: Elektrische Maschinen, 15.Auflage, Hanser Verlag München"
Cleaner solution
Apply a (small) DC voltage step to a test circuit, consisting of a resistor and one of the windings in serial combination. Capture the current with an oscilloscope. Measure the time constant of the system and calculate the inductance L of the winding. Repeat this process for the second winding. The winding with the higher inductance value should be the main winding.
Comment: while the auxiliary winding may be thinner there are fewer windings. So is this an accurate method of measurement?
Comment: I can't confirm that this is a completely accurate method, but it was the first thing that came to my mind when I saw the question. Nevertheless, although there will be fewer windings the auxiliary winding should have a noticeably higher resistance. According to the things I learned (and also according to the book) the difference should be enough. Still it's possible that I'm wrong.
Comment: I guess the other (more expensive) test could be to use an LCR meter and measure the inductance of the two windings.
Comment: I think that this would be the cleanest solution, but therefore one needs to have a LCR meter.
Comment: One other method would be to have a look at the (current) step response of each winding + a resistor. The time constant could be used to calculate the inductance L of each winding. However, therefore one needs to have an oscilloscope.
Answer:
If the direction of rotaion of motor is shown or known then ther is a solution except exact value of capactitor ( however the norms says.. loking at shaft end motor should generally rotate in clock-wise direction. I am not sure of your motor).
connect a capacitor as suggested by Simon and connect supply between common terminal and capacitor ( winding) termnal and if motor runs in opposite direction then the shift the connection to other treminal of capacitor . Now the motor will rotate in the specified direction. the motor terminal which is connected directly to supply is main winding and the one connected through capacitor is aux. winding.
vtingole
Answer: first of all identify common terminal by checking resistance. and connect the capacitor b/w main and aux terminal. and connect the terminal of common and main or aux as per required direction of rotation.
Answer: The aux winding should have the greatest resistance as this is what puts it out of phase with main winding to give an apparent rotating magnetic field.
This is achieved by using thinner wire or alternately resistance wire.
Comment: Welcome to EE.SE. "*The aux winding should have the greatest resistance as this is what puts it out of phase with main winding ...*". This is incorrect. It is the combination of auxiliary winding capacitance, inductance and resistance that causes the phase-shift. See the answer that was accepted six months ago.


Can I use a custom Splash screen?

Question: The default Splash screens are cool, but I'd like to add some of my own work to remind me of how awesome I am (no, not really).

Is it possible to customize/change the splash screen?
Answer: You have to build this with Blender.
It is located at /blender/release/datafiles/splash.png — (old svn link) (new git link).
Just replace1 this file with a similar one.

1Here is a link to the entry on the wiki on how to correctly change it.
You can grab an old template here which should still work and size your image accordingly (src). The template is also in the same directory as splash_template.xcf
BlenderCookie has a tutorial on building Blender (download from archives) in which the author changes the splash screen. (He uses mac but the majority of process can be done pretty much the same way for other platforms)
Comment: Currently, more cmake is used, how would you do it?
Comment: This is cool! I have been wondering if you could do this.
Comment: @Nate_Sycro27 Yep and now that blender is super easy to build you can literally download some tools and type a few commands and that's it.
Answer: You can do that with a custom build of blender.
The image is located in the source at: /blender/blender/release/datafiles/splash.png
If you're interested here's a link on how to build blender from source: http://wiki.blender.org/index.php/Dev:Doc/Building_Blender
If your on Mac, CGCookie has a tutorial (archive) on how to build blender with custom splash screen.
Comment: Currently, more cmake is used, how would you do it?
Answer: It's also possible to use Application Templates with custom splash screen.
On Windows you would create a bl_app_templates_user folder in your preferences scripts folder - C:\Users\[username]\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\startup\bl_app_templates_user\ This folder can contain a folder with your template with startup file, add-ons, themes, keymaps and other things and if you include a custom 1000x500px png image called splash.png, it's going to be the splash screen if you start Blender with --app-template your_template_name argument (template name is the name of the template folder in bl_app_templates_user\). You can see system templates in Blender's installation directory(something like C:\Program Files\Blender Foundation\Blender 4.0\4.0\scripts\startup\bl_app_templates_system) and could copy one to start creating your own from it). So after creating a template just make a Windows shortcut with a target like "C:\Program Files\Blender Foundation\Blender 4.0\blender.exe" --app-template my_template and use it to start Blender:

Can I use a custom Splash screen?


Packet socket in promiscuous mode only receiving local traffic

Question: I have a socket created with socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL)), and I've set it into promiscuous mode using:
struct ifreq ifr;
strncpy((char*)ifr.ifr_name, interface, IF_NAMESIZE);
if(ioctl(sock, SIOCGIFINDEX, &ifr)<0) fail(2);

struct packet_mreq mr;
memset(&mr, 0, sizeof(mr));
mr.mr_ifindex = ifr.ifr_ifindex;
mr.mr_type = PACKET_MR_PROMISC;
if(setsockopt(sock, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mr, sizeof(mr)) < 0) fail(2);

The problem is that when I do a read() from the socket, it only returns data that's going from or coming to my computer.
How can I get it to read and process all packets on the network?
Wireshark shows all the packets fine, so I know it isn't my computer or NIC. ifconfig reports that it's PROMISC when it is running.
Answer: Along with Rob Jones' suggestion, try a tool like Wireshark to make sure that you're receiving the packets that you expect at the interface. At least that will confirm (or deny) that you have a problem with your code.
Also need to make sure that the interface itself is set to promiscuous mode.
If not then you can use the ioctl() to set it:
ifr.ifr_flags |= IFF_PROMISC;
if( ioctl(sock, SIOCSIFFLAGS, &ifr) != 0 )
{
    // handle error here
}

While your application is running, make sure that ifconfig reports the PROMISC flag for that interface.
Note that this will need to be executed as a privileged user.

Tried out the code as presented. Works for me. Of course (due to the test on line 102) this will only print details for TCP traffic.
Comment: It does, but the socket still won't receive other traffic.
Comment: I managed to fix it on my end, and this was the most helpful answer. Thanks!
Answer: Try using SOCK_PACKET as the second argument to socket(), rather than SOCK_RAW.
If you're on a switch you will probably only see packets destined to, or originating from your computer.  Try a hub.
Comment: Fair enough.  Are you running as a privileged user?
Comment: If I do that, the bind() fails. Also, it's deprecated.
Answer: This is likely not a software problem.
You're likely using the wrong hardware.  Your computer is probably hooked up to a Switch.
Switches are smart enough to "learn" which computers are on which ports, and route traffic only to where it needs to go.  Hence, the switch is filtering your packets for you.
To fix this, you need to get a Hub.  Although Hubs and Switches appear very similar, they work differently.  The Hub is dumb, and will route all traffic to all ports, enabling you to see other traffic in promiscuous mode.
Note that even if you replace the device that your computer connects to, it is likely connected to more switches up-stream, which will also limit traffic.  Hence, you won't be able to sniff traffic from much further away than your own hub or test-lab setup.
Answer: Your switch port also needs to be configured appropriately (SPAN port in Cisco world).
See here for more details:
http://www.winpcap.org/misc/faq.htm#Q-22
And here is the info from Cisco regarding how SPAN ports work:
http://www.cisco.com/en/US/products/hw/switches/ps708/products_tech_note09186a008015c612.shtml


Does independence of the sequence $f(A_i, B)$ imply the sequence is independent of $B$?

Question: Suppose $B, \{A_i: i \in \omega\}$ are i.i.d. random variables with uniform distributions on $[0,1]$. If $f$ is a map such that $\{f(A_i, B): i \in \omega\}$ are independent, must $\{f(A_i, B): i \in \omega\}$ also be independent of $B$?
Comment: I can prove it for discrete uniform distributions. I wonder if that helps for continuous uniform distributions.
Comment: Do you think there is a counterexample for general (i.e. non-uniform) distributions?
Comment: No, I think any distributions at all are ok, even a different one for each of the arguments. See the stuff I added to my answer.
Answer: It is true.
Let $\chi_Z(x,y)$ be the indicator function of the set $\lbrace (x,y) \,|\, f(x,y)\in Z\rbrace$ for some set $Z$.
The condition that the events $f(A_1,B)\in Z$ and $f(A_2,B)\in Z$ are independent is that
$$ \int_{[0,1]^3} \chi_Z(x,y)\chi_Z(x'y)\,dxdx'dy
   = \int_{[0,1]^2} \chi_Z(x,y) \,dxdy \ \ \int_{[0,1]^2} \chi_Z(x',y') \,dx'dy'.$$
Define $g(y) = \int_0^1 \chi_Z(x,y)\,dx$.  Then the above condition can be rearranged into
$$ \int_{[0,1]^2} g(y) (g(y)-g(y'))\, dy dy' = 0.$$
That's just a change of variables from
$$ \int_{[0,1]^2} g(y') (g(y)-g(y'))\, dy dy' = 0,$$
so we can subtract the two to get
$$ \int_{[0,1]^2} (g(y)-g(y'))^2 \,dydy' = 0$$
which by positivity means $g(y)$ is constant a.e.. Harking back to the definition of $\chi_Z$ and noting that the set $Z$ was arbitrary, we see that $f(A_1,B)$ is independent of $B$.
I have only considered pairwise independence, but once you find that $g(y)$ is independent of $y$ it makes the whole lot of them independent.  At least, it seems so at 3am...
ADDED after waking up: At the moment I can't see how uniform distributions are needed for this argument. Just consider any vertical measure $\mu$ and horizontal measure $\nu$ and replace $dx$ by $d\mu$, $dy$ by $d\nu$, etc, in the above argument. Still works, doesn't it?
MORE ADDED: Nate's question leads me to note the following, which  surely must be well-known in the theory of exchangeable random variables (but I didn't know it).
Theorem. Let $X,Y$ be random variables such that $(X,Y)$ and $(Y,X)$ have the same distribution.  Then $X$ and $Y$ are independent iff for all measurable sets $S$, $P(X\in S \wedge Y\in S)=P(X\in S)^2$.
Proof. Let $S,T$ be measurable sets. First assume $S$ and $T$ are disjoint.  Since by the exchangeability assumption $P(X\in T\wedge Y\in S)=P(X\in S\wedge Y\in T)$, we have
\begin{align}
  2 P(X\in S\wedge Y\in T)&=P(X,Y\in S\cup T) - P(X,Y\in S) - P(X,Y\in T) \\
   &= P(X\in S\cup T)^2 - P(X\in S)^2 - P(X\in T)^2 \\
   &= (P(X\in S) + P(X\in T))^2 - P(X\in S)^2 - P(X\in T)^2 \\
   &= 2 P(X\in S) P(X\in T) \\
   &= 2 P(X\in S) P(Y\in T).
\end{align}
If $S$ and $T$ are not disjoint, break $P(X\in S\wedge Y\in T)$ into four disjoint cases like $P(X\in S\wedge Y\in T\setminus S)$ and apply the above to each.  It works.
Comment: In general, to show two random variables are independent, you have to show $P(X \in U, Y \in V) = P(X \in U) P(Y \in V)$ for $U,V$ ranging over an appropriately rich collection of sets.  Why does it suffice to prove the special case where $U=V=Z$?  Sets of the form $Z \times Z$ don't generate the product $\sigma$-algebra, do they?
Comment: @Nate : What you say is correct, but I don't think I'm making that mistake. Independence of $X$ and $Y$ implies that the events $X\in Z$ and $Y\in Z$ are independent; the converse is false but I don't use it. Once we know $g(y)$ is a.e. constant, the distributions of $f(A,B)$ conditional on any two non-null $B$-events are the same.  But let me know if you still think there's a problem.
Comment: @Nate : To my surprise, the converse *is* true in this case, see my addition.