Yugioh: Sacrifice a field card to destroy target monster

Question: Is there a Yugioh card with the effect (activated on the field) that you can discard a card in your hand and/or one you control to target another card on the field and destroy it?  This would, in theory, be nice to couple with Master Hyperion -- because you could then use Master Hyperion's effect to send the card recently put in the graveyard to the banished area to resolve Hyperion's effect.
Comment: Are you asking specifically about Fairy-type cards or cards in general? There are quite a few which don't work with Hyperion, though.
Answer: Snipe Hunter is your guy. He can discard as many cards from your hand as you like to target any card on the field. Then you roll a die and if it's 2, 3, 4 or 5, the card is destroyed.
A good once-per-turn option is Scrap Dragon. He allows you to target one card on each side of the field which then get destroyed.
Spell and Trap wise, there's Raigeki Break, Phoenix Wing Wind Blast and Dark Core. There might be more of them, see my advice below.
Other than that, there are mainly only specific cards which won't work with Hyperion, such as Exiled Force or Chiron the Mage. That kind of card isn't that rare.
You might want to look for Cards that destroy cards on the field on the wikia. Most of them have a drawback, which is often discarding or Tributing cards.
Answer: May I suggest the monster card effect called Exiled Force?

You can Tribute this card to target 1 monster on the field; destroy that target.

Another option could be the trap card called Raigeki Break

Discard 1 card, then target 1 card on the field; destroy it.

This last one card matches with your requirement.
Answer: you can use this list to Send cards from your Deck to the Graveyard or this list to Send cards from your Deck to the Graveyard at a cost
there are also cards like Card Destruction or Graceful Charity might come in handy, while the first can wipe out your entire hand if you have a hand full of light type fairies, the second can allow you the chance in drawing 2 and sending them right into the grave yard.
Your best bet is to find cards which allow you to draw a new card at the same time as discarding, if they draw before discard then you have a chance in drawing a light type fairy
your other option is to stock up on weaker ones and use them as fodder in Defense Mode, even if your opponent works out what your doing they have no choice but to wipe them out unless they have cards which can deal direct damage


Convert existing BibTeX to BibJSON

Question: I'm interested in converting my existing bibtex file (generated from Mendeley) into BibJSON format (http://okfnlabs.org/bibjson/), since it would be helpful for me for sharing and other integration purposes. Do you know of any code or script that can take in an existing BibTeX file (*.bib) and create the file in BibJSON format.
Answer: UPDATE 2021: Citeproc is now integrated with Pandoc. Use something like:
pandoc foo.bib -t csljson -o foo.json

ORIGINAL ANSWER:
You can use pandoc-citeproc, which is a part of the excellent pandoc program, to convert your .bib file to a .json file.
pandoc-citeproc --bib2json foo.bib > foo.json

But I doubt the output will be exactly what you need, because the specs you have linked seem to go beyond what pandoc offers.
Comment: Citeproc is now integrated with Pandoc. Use something like: `pandoc biblio.bib -t csljson -o biblio.json`
Answer: If you are familiar with Ruby, you can try  bibtex-ruby  module. It has conversions to XML and JSON (to_json). Thugh I don't know how close the output is to BibJSON format.
Answer: On the project site of BibJSON: http://openbiblio.net/ they refer to https://github.com/zotero/translators which is a

free, easy-to-use tool to help you collect, organize, cite, and share your research sources.

But the Merge-Request for BibJSON into Zotero got lost. So it does not support export into BibJSON. Maybe CSL Json is a more popular format?

Convert existing BibTeX to BibJSON


No longer want mypackage.myapp (pid 7433): hidden #16 error on using LoginButton?

Question: I've created a sample project which loads a fragment containing LoginButton widget. It works absolutely fine, returning me GraphUser object. Then I embedded this code into my active project. Initially, it returned me the GraphUser object.
However, few days later when I checked the code again it gives me this error after submitting the facebook user credentials:
I/ActivityManager(215): No longer want com.org.app (pid 7433): hidden #16
I/WindowManager(215): WIN DEATH: Window{40f8d808 com.org.app/com.facebook.LoginActivity paused=false}
Also, my activity is destroyed.
Please note, the same fragment with the LoginButton runs absolutely fine in a different project.
Answer: Issue solved. Created a new android project. Shifted all my files to it. The issue occurred, I think, due to git merge.


Memcached 1 Meg Limit, Enyim .Net Client

Question: There is a limit of 1 meg for objects in memcached. Whats the best way to store objects larger than this?
I'm using the Enyim .Net client.
Answer: It is possible to increase the max size of an item greater than 1MB in memcached since 1.4.2:
http://code.google.com/p/memcached/wiki/ReleaseNotes142#Configurable_maximum_item_size
Note older versions of the Enyim.Caching client still have a 1MB hardcoded internal limit.
Answer: I use memcached via the C API but the situation is essentially the same.  You'd need to find a way to split the data up yourself and provide a way to generate a set of keys to access the parts based on your master key.  You'll also probably need some kind of header stored in the first blob that can tell you if you are looking at a multi-part cache object.
I don't think there is anything out there that will do the heavy lifting here for you but then I'm doing this in C++ not .NET, perhaps someone has written a module already.  Otherwise...I'd suggest there is a gap in the market :)
Comment: thanks for the idea. It's a collection of objects, so should be very straight forward to split up. cheers


iMessage not working on iPhone without sim

Question: My friend never had a sim for her iPhone 4. She uses the phone as a skype device and camera (and she loved it that way!). I recently persuaded her to update to iOS 5.1, created a new iCloud account (she never had one), enabled iMessage. However, she does not receive any iMessages. She can send out iMessages but they do not reach me (I have a working iPhone with iCloud, iMessages). I have restarted her machine several times and did a clean install of iOS 5.1. Can anyone tell me what might be incorrect here? (I see that a lot of people have an iPhone without sim working as an iMessage device.)
Answer: I can iMessage from my Wifi only iPad, so it can be done. I have a feeling it has something to do with the sending or receiving address. I would check the Messages setting to make sure it is set to her Apple ID/email address. I would also try, instead of her sending it to your phone number, having her send it to your Apple ID/email address, as that is more universally recognized. It would be interesting to know if she can iMessage other iPhones as well.
Comment: This solved it for me. I had to ensure the phone with no SIM used my Apple ID (not phone) in the contact and I also set my iMessage to start conversations using my Apple ID and not my phone number.
Answer: I turned off iMessage, restarted the iPhone and turned iMessage back on and it suddenly can recieve and send iMessages.


What is the genetic basis of blood type (ABO) system?

Question: What is the genetic basis of the A/B/B+/O/etc. blood type system? Are there definitive loci that correspond to each or can multiple different genotypes produce the same antigen profile? Also, is the blood type of a child necessarily one of the blood types of the parents, or can an A/B female cross to A/B male produce a child with blood type O?
Answer: I can answer only half your question.
It is not necessary that the child has to have the blood group of parents.
The inheritance is like this :
1.There are 3 alleles Ia , Ib and Io.
2.Ia and Ib are codominant i.e. they will both be expressed if present together.
3.Ia and Ib are dominant over Io. So, blood group O can only be expressed if the genotype is IoIo. IaIa or IaIo is blood group A and IbIb or IbIo is blood group B.
5.IaIb is blood group AB
So in the case of both the parents being AB blood group,the child can not have O group.S/he can have any other blood group.
The inheritance of negative and positive blood group follows simple mendelian inheritance.
Please feel free to correct me!
Answer: There is only one locus involved in ABO blood type, the ABO gene on chromosome 9. It has three alleles: A, B, and O.
We have two copies of every gene, one from each parent. Because the O allele is recessive to A and B, there are blood types with multiple genotypes. AO and AA will both produce blood type A, and BO and BB will both produce blood type B. Only OO will produce blood type O, and AB will get you blood type AB. The specific cross you mentioned (AB x AB) will never produce a child with blood type O, because neither of the parents had any O alleles for the child to inherit. However, any other blood type is possible with this particular cross.
The + or - you sometimes see is a separate system called the rhesus blood type system. The genetics involved in that are actually a bit complicated, but they don't involve the ABO gene at all.


Should I pay off my student loan before buying a house?

Question: Should I pay off my student loan before buying a house?
Comment: What country? What are the repayment terms for the loan?
Comment: Duplicate question *for the UK* with more details here: http://money.stackexchange.com/questions/46547/should-i-pay-off-a-student-loan-before-getting-a-mortgage-given-i-have-a-large
Comment: Related, but not a duplicate: http://money.stackexchange.com/questions/187/will-our-hefty-student-loans-affect-our-chances-of-getting-a-mortgage
Answer: Paying off your student loan before buying a house is certainly a great risk reduction move for you. It will lower your debt to income ratio allowing your mortgage approval to go easier and it will free up more of your dollars to pay for the many miscellaneous projects that come with buying a house.
I think that if you are considering paying off your student loan before buying a house that means that your student loans are an amount you can fathom paying off and that you are motivated to be rid of your student loan debt.
Go for it and pay off your student loan.
Comment: I think this very much depends on the terms of the student loan and how it affects credit, which in turn will very much depend on the country in question.
Answer: It depends on the terms. Student loans are often very low interest loans which allow you to spread your costs of education over a long time without incurring too much interest. They are often government subsidized.
On the other hand, you often get better mortgage rates if you can bring a down payment for the house. Therefore, it might be more beneficial for you to use money for a down payment than paying off the student load.
Answer: There may be specific answers that can be determined based on the interest rates, amounts, tax provisions, etc. But I'm here to tell you...
It is much easier (i.e., less stressful) to own a home when you have less debt. Pay off any and every debt you can before purchasing a home because there will always be something requiring you to spend money once you own one.
Answer: It might be a good idea, because later in life if a large expense shows up or an income source disappears, you will only have the mortgage payment, rather than a mortgage AND a student loan payment.
Answer: One extremely important aspect that must be taken into consideration is the state of the housing market. If prices are rising it will probably be a false economy to delay your house purchase. Say you pay off a £5,000 student loan, thus delaying your house purchase another year you could well end up forking out an extra £10,000 on the mortgage due to the rise in house prices.
Of course, if the housing market is falling then, without a doubt, pay off the student debt.
Answer: IMO student loans are junk debt that should be dealt with as soon as possible.
Buying a house comes with risks and expenses (repairs, maintenance, etc) and dealing with a student loan at the same time just makes it tougher. Personally, I would try to pay off at least a few of the loans first.


GNU/Linux contest logging software?

Question: What contest logging software exists for the GNU/Linux operating system?
Comment: http://meta.ham.stackexchange.com/questions/12/how-about-list-questions Voting to close as "too broad".
Comment: I started working on one, but most of the contest loggers are written in VB on Microsoft Access Databases.
Answer: I've used CQRLOG which is built on MySQL but otherwise has many of the same features as other loggers and is fully customizable. If that's too much and you're looking for a simpler solution, Xlog is a barebones logger that can still interchange data with some of the Linux PSK and other digital mode software. Both support all the popular export formats, including adif and Cabrillo. The Arch Linux Wiki has links to another 8 programs that might help, including YFKtest or TLF if you're looking for a barebones console logger or FDLog with field-day-specific features and networking.
Comment: Another vote for CQRLOG.
Comment: Yep, but CQRLOG is rather a general logging program with all whistles and bells; not really a contest logging program.
Answer: A simple way to get a Linux logger is to use a windows logger under WINE Windows Program Loader, or something similar. I've done it before and it works fine, however it can cause problems on a slow computer.
Comment: I personally use N1MM on Win7 in the shack, my mobile/portable setup uses N1MM running under Wine on Linux Mint (Ubuntu) and it work fine.
Answer: Writelog, N1MM and MMTTY all run under Codeweavers CrossOver, the commercial version of Wine.
Apart from being much easier and convenient to use than Wine, my success rate with CrossOver is also a bit higher. Furthermore, I have no problem opening my wallet for this decently priced software in support of this company. (Disclosure: No conflict of interests.)

GNU/Linux contest logging software?


Has the creator been interviewed about when the Attack on Titan story takes place?

Question: Lots of speculations have been made as to the time frame and location using clues from within the manga and animation.....but why not just ask the series creator if he gave it much thought or is the story just a mishmash of past and future technologies. I'm sure much Japanese writing has been done on this topic that hasn't been translated.....or perhaps, we Westerners are more concerned about this than we should be.
Comment: Closely related: [When and where does Attack on Titan take place?](https://anime.stackexchange.com/q/4615)
Answer: I always thought of it as a futuristic collapsed society type theme. They were forced to build walls and revert back to medieval society but they focused their technology on their ODM gear to combat the titans. There is reference to the past (our current real life time). Perhaps the biggest supporting evidence of this was episode 6 where Misaka's kidnappers are talking about her race and they state:
"she's exotic. what they used to call an Oriental.You know about all that right? back when there used to be different breeds of people, a bunch of them from the far east came scrambling here for safety. the old perverts in the capital really go for that sort of thing. this little beauty's going to fetch a mint at auction. it's great business. she's the last of her kind. all the rest of her people died out."
hope that helps. the year that it starts out on is 845 so the yearly calendar reset for some important reason, but it hasn't revealed a lot about the history yet (just that the titans appeared over 100 years ago.) As far as location goes it's safe to assume that it is probably German. accounting for the kidnapper's claim that there is currently only one race and we have names like:
-Yaeger (german for hunter)
-Arlert is old german anglo-saxon, and Armin's wiki page trivia section states that "The name 'Armin' may have multiple meanings, either from an old German word meaning "whole", or "Herman", meaning "soldier"". http://shingekinokyojin.wikia.com/wiki/Armin_Arlert
-Erwin - Derived from the Germanic name Hariwini, composed of the elements hari "army" and win "friend".
Add it all up with a lot of blonde hair (Armin, Reiner, Nanaba, Christa, Annie, Erwin, etc) and it seems that they were leaning toward a German-oriented character base with names that are literal puns toward the fact that they are soldiers.


gdb Info manual

Question: I can't seem to find the gdb Info manual file on the gnu.org documentation page for gdb, which only seems to have a PDF version and an online version. I've found and manually installed several other Info manuals from GNU before, but can't seem to find one for gdb. Anyone know where I can find it?
Answer: Apparently the doc in info format is not directly available.  However the texinfo file  (from wich the info file is generated) is included in the sources as doc/gdb.texinfo.  So if you install gdb from the sources, you should have the info file properly installed and accessible from emacs.
On debian systems, the documentation is not included in the gdb package but in the package gdb-doc.  Additionnaly, this package is in section "non-free" because the GNU Free Documentation License (FDL) isn't compliant with the Debian Free Software Guidelines (DFSG).
Comment: Thanks for the additional info. I did in fact look for the texinfo file as well. With your answer I now know why I couldn't find either file (I'm on a Debian system).
Answer: Upon reflection, this is a more general Linux question and should have been asked on Unix & Linux Stack Exchange. I found an answer there.

gdb Info manual


Should I unit test small projects?

Question: I develop small projects, and the testing is usually a functional test when I verify if the service is working as I were the user. Is this ok with small projects of 2-3 people? How do you think unit testing could help?
I see it as a waste of time.
Comment: Unit tests are never, ever, ever, ever, ever a waste of time. Never.  Ever.
Comment: This isn't so much an answer, but if the project is important enough to have 3 people working on it, it's important enough to get some testing on it too. I am torn about whether my single-person project should have testing on it!
Answer: Short answer:
Yes you should unit test small projects.
Longer answer:
Like you said in your question, you currently test your code functionally.  Why are you doing that?  Because testing is useful!  Unit tests are the same.  If you ever go back to refactor your code, add or edit features a suite of unit tests will give you instant feedback that your changes aren't breaking anything.
I'd really recommend trying out Test Driven Development.  You think about what you need, right a failed test and then add the code to make it pass.  Lather, rinse, repeat.  Here is a good list of benifits from writing code this way, or run a google search on the topic, there are many resources out there.  TDD is easy to understand, really hard to master.
http://blog.jtimothyking.com/2006/07/11/twelve-benefits-of-writing-unit-tests-first
Comment: great answer! I don't always do test driven development but writing even a few test can help write better code that will help when that "small project" becomes the next big one. ;0)
Answer: Testing is a means to an end, not an end in itself.  If you are satisfied with the quality of your work using your current development and testing practices, there is no need for additional work.  If you are not satisfied with the quality of your work, writing unit tests is one possible path to improvement.
I cannot guarantee that writing unit tests will make things better for you. In some circumstances it can be a waste of time, e.g. when the developers do not want to write unit tests, or when the unit tests focus on things that are unimportant or unlikely to have bugs.  In the right circumstances, they can make a big difference.  When I was a developer, I wrote unit tests, and for me it was a productive practice.
Answer: Absolutely you should write unit tests. There's no guarantee that your small project isn't going to get added to at some later date - or that the next version of your operating system won't deprecate the calls your project is making to something. Or any of innumerable other strange things won't happen. It's not that uncommon for someone's prototype to become the core of a new application, and morph into a maintenance nightmare because the original assumption that this was throwaway code wasn't correct.
If you can avoid getting bitten by any of these possibilities, avoid them. As far as that goes, unit tests are the condoms of the software world: they protect against all sorts of unforeseen events, as well as against the things you expect them to protect against.
Answer: TL;DR answer

Yes, unit tests are worthwhile even on small projects.

Full answer
For many years I was under the misapprehension that I didn't have enough time to write unit tests for my code. When I did write tests, they were bloated, heavy things which only encouraged me to think that I should only ever write unit tests when I knew they were needed.
Then I started to use Test Driven Development and found it to be a complete revelation. I'm now firmly convinced that I don't have the time not to write unit-tests.
In my experience, by developing with testing in mind you end up with cleaner interfaces, more focussed classes & modules and generally more SOLID, testable code.
Every time I work with legacy code which doesn't have unit tests and have to manually test something, I keep thinking "this would be so much quicker if this code already had unit tests". Every time I have to try and add unit test functionality to code with high coupling, I keep thinking "this would be so much easier if it had been written in a de-coupled way".
Comparing and contrasting the two experimental stations that I support. One has been around for a while and has a great deal of legacy code, while the other is relatively new.
When adding functionality to the old lab, it is often a case of getting down to the lab and spending many hours working through the implications of the functionality they need and how I can add that functionality without affecting any of the other functionality. The code is simply not set up to allow off-line testing, so pretty much everything has to be developed on-line. If I did try to develop off-line then I would end up with more mock objects than would be reasonable.
In the newer lab, I can usually add functionality by developing it off-line at my desk, mocking out only those things which are immediately required, and then only spending a short time in the lab, ironing out any remaining problems not picked up off-line.
Answer: Project size should not be a factor to consider for skipping unit tests.
Most people here will hate me if I give you good reasons to not unit test. These are the only three I consider:

Time pressure and poor testing experience
If you are running under time pressure and do not have good experience testing your software. Do not start now. On the long term testing your software is a huge productivity gain, but on the beginning you will work slower. Learn TDD when your deadline/job is not at stake
Usage frequency
If you are working on something that you will only run a few times, delete later and a bug will not destroy your life, then it is OK not to write  unit tests
Maintenance
If your tool does only ONE single thing and you are quite sure that you will never have to touch it again (hardly ever the case), then it is also OK not to do unit testing.

Should I unit test small projects?


What is the penalty for bidding out of turn?

Question: In duplicate bridge, what is the penalty for someone bidding out of turn?  Specifically, opening the bid by accident while sitting to the right of the dealer.
Comment: Be specific: a a **pass**, a **bid*, or a **double or redouble**? Three different rules apply (30, 31 or 32 respectively), one for each circumstance.
Comment: The 2008 Rules are here, with this situation covered on pages 42-44 (plus Rule 23 possibly): http://www.acbl.org/assets/documents/play/Laws-of-Duplicate-Bridge.pdf
Answer: Here is a summary of the relevant rules that @Pieter Geerkens linked to. I am leaving out some of the more sophisticated points, for example, the fact that an artificial/conventional pass call is treated as a bid for the purposes of these rules. The guiding principle is not to punish the out-of-turn bidder, but to make it impossible for the offending team to benefit from the information improperly exchanged. That's why many of them refer to Law 23, which allows a TD to further adjust the score if it is determined that the offending team gained an advantage by the improper call.
In most cases, a bid on LHO's turn is treated as a change in call, which is treated separately. In practice this is a difficult mistake to make--you don't usually make two bids in immediate succession.
Pass out of Turn

If no player has bid yet, offender must pass at next opportunity.
After any player has bid, offender must pass at next opportunity; in addition, if offender passes at his partner's turn to call, offender's partner may not double or redouble.

Bid out of Turn

If offender bids on RHO's turn, and RHO passes, offender must make the same bid, but there is no other penalty.
If offender bids on RHO's turn, and RHO does not pass, offender may make any call. If the call is the same "denomination" as the original call (same suit or NT), offender's partner must pass at next opportunity. If the call is any other denomination, offender's partner must pass through the entire auction, and if offender's team defends, lead restrictions will go into effect (more on that in a bit).
To explain the differences above: If partner bids 1C, and I get excited and bid to 2C before RHO passes, no harm done. If partner bids 1C, and I hasten and bid 2C, and RHO says, wait! I wanted to bid 2H, and I say OK, fine, 3C, that's not a very big deal. But if I say, wait, based on opponent's 2H bid, I want to bid diamonds instead... that conveys a huge amount of information about my hand to my partner, and allowing partner to continue to bid would be unfair.
If offender bids on partner's turn, partner must pass through the entire auction, and lead restrictions may apply here as well.
Lead restrictions: If a specific suit is named, declarer can require the offender's partner to either lead, or not lead, that suit at the player's first opportunity. A prohibition to lead the suit lasts as long as that player keeps the lead. If no specific suit is named, the declarer can prohibit offender's partner from leading any one suit.

Double / Redouble out of Turn

In all cases, opponents have the choice to allow the double or redouble to stand. In this case, there is no penalty.
If offender doubles on partner's turn, partner must pass through the auction.
If offender doubles on RHO's turn, and RHO passes, the offender must make the same double or redouble, and offender's partner must pass at the next opportunity.
If offender doubles on RHO's turn, and RHO does not pass, the offender may make any bid, but offender's partner must pass through the auction.
Comment: Ha! You beat me by 90 seconds; Well done. I did include Rule 23 as well though.
Answer: Here are the relevant rules for the various scenarios under your questions:
LAW 30 - PASS OUT OF ROTATION

When a player has passed out of rotation and the call
is canceled, the option in Law 29A not having been
exercised, the following provisions apply (if the pass is
artificial, see C below):
A. Before Any Player Has Bid
When a player has passed out of rotation before any
player has bid, the offender must pass when next it
is his turn to call and Law 23 may apply.
...

LAW 31 - BID OUT OF ROTATION

When a player has bid out of rotation, has passed artificially
or has passed partner's artificial call (see Law
30C) and the call is canceled, the option in Law 29A not
having been exercised, the following provisions apply:
A. RHO's Turn
When the offender has called at his RHO's turn to
call, then:
1. if that opponent passes, offender must repeat the
call out of rotation. When that call is legal there
is no rectification.
2. if that opponent makes a legal* bid, double or redouble,
offender may make any legal call. When
this call
(a) repeats the denomination of his bid out of
rotation, offender's partner must pass when
next it is his turn to call (see Law 23).
(b) does not repeat the denomination of his bid
out of rotation, or if the call out of rotation
was an artificial pass or a pass of partner's
artificial call, the lead restrictions in Law 26
may apply, and offender's partner must pass
whenever it is his turn to call (see Law 23).
....

LAW 32 - DOUBLE OR REDOUBLE OUT OF ROTATION

A double or redouble out of rotation may be accepted
at the option of the opponent next in rotation (see Law
29A), except that an inadmissible double or redouble
may never be accepted. If offender's LHO nevertheless
calls, see Law 36. If the call out of rotation is not accepted,
it is canceled, the lead restriction in Law 26B
may apply and:
...
B. Made at RHO's Turn to Call
If a double or redouble out of rotation has been
made when it was the offender's RHO's turn to call,
then:
1. if offender's RHO passes, offender must repeat
his out-of-rotation double or redouble and there
is no rectification unless the double or redouble
is inadmissible, in which case Law 36 applies.
2. if offender's RHO bids, doubles or redoubles, the
offender may in turn make any legal call, but offender's
partner must pass whenever it is his turn
to call. See Law 23 if the pass damages the nonoffending
side.

LAW 23 - AWARENESS OF POTENTIAL DAMAGE

Whenever, in the opinion of the Director, an offender
could have been aware at the time of his irregularity
that this could well damage the non-offending side, the
Director shall require the auction and play to continue
(if not completed). When the play has been completed,
the Director awards an adjusted score if he considers
the offending side has gained an advantage through the
irregularity*.
* As, for example, by partner's enforced pass.


Why did the Buddha suffer before he died?

Question: I understand that the Buddha became severely ill prior to his death as a result of eating bad food. I also was under the impression that perfectly enlightened beings have obliterated, or rendered ineffective, all of their karma. If this is the case, why would the Buddha, the most perfectly enlightened of all, experience great suffering at the end of his life?
Answer: "I also was under the impression that perfectly enlightened beings have obliterated, or rendered ineffective, all of their karma"
The five skhandas are roughly understood as "past kamma". Even arahants experience the fruits of their past kamma and are only free of it in parinibbana. For example, there are suttas describing arahants being hurt. In the case of the Buddha specifically, there's a well known one where he had his foot hurt:

I have heard that on one occasion the Blessed One was staying near Rajagaha at the Maddakucchi Deer Reserve. Now at that time his foot had been pierced by a stone sliver. Excruciating were the bodily feelings that developed within him — painful, fierce, sharp, wracking, repellent, disagreeable — but he endured them mindful, alert, & unperturbed. Having had his outer robe folded in four and laid out, he lay down on his right side in the lion's posture, with one foot placed on top of the other, mindful & alert.
-- SN 1.38

"If this is the case, why would the Buddha, the most perfectly enlightened of all, experience great suffering at the end of his life?"
It's generally understood that he suffered body pain (at least when not in jhana). His own teaching carries this (like the quote above):

"And what are the fermentations to be abandoned by tolerating? There is the case where a monk, reflecting appropriately, endures. He tolerates cold, heat, hunger, & thirst; the touch of flies, mosquitoes, wind, sun, & reptiles; ill-spoken, unwelcome words & bodily feelings that, when they arise, are painful, racking, sharp, piercing, disagreeable, displeasing, & menacing to life. The fermentations, vexation, or fever that would arise if he were not to tolerate these things do not arise for him when he tolerates them. These are called the fermentations to be abandoned by tolerating.
-- MN 2

A well known sutta on this subject is the The Arrow which illustrates the differences between pain and suffering. Thus, pain could be understood as simply bodily discomfort (even if sharp), but unable to do anything beyond that, say, to his mind (which is naturally not the case for any "normal" person). However, like in the foot episode, he does appear managing these discomforts:

Then the Blessed One — having spent most of the night instructing, urging, rousing, & encouraging the Kapilavatthu Sakyans with a Dhamma talk — said to Ven. Ananda, "Ananda, speak to the Kapilavatthu Sakyans about the person who follows the practice for one in training. My back aches. I will rest it."
-- MN 53

Finally, body pain (vedana in general) does not cease permanently with nibbana, if a body still has vitality.
Answer: Buddha did not experience suffering(mental). He experienced pain due to poor health during his final days. Enlightened beings do not create new Karmas. Also, they have removed the potential of all their past Karmas to give future births. But they can still face the consequences while they live.
Answer: The Buddha was still a human being in the sense that he had a physical body as a results of the 5 aggregates.
He was once asked if he was in pain regarding his pains in the back. His answer was that there was pain but he was not bothered by it.
As an enlightened being he had destroyed all defilements and fetters and would therefore not identify or take ownership of the pain. There would be noone to do that. There would just be pain - an impersonal phenomena.
Answer: Bear in mind that there's Suffering and suffering.  "suffering" (lower-case "s") is the typical way in which the word is used.  It is the workaday definition of "suffering", i.e., to be in discomfort, to not like something because it brings about physical or mental anguish: being hungry, in pain, heartbroken, in grief, etc.  Believe it or not, these kinds of sufferings are rooted largely in our physiology, i.e., our nervous systems.  We are wired to be repelled by pain, want to sate hunger, have mate(s), etc., because it is how we have evolved as beings, and for good reason.  How long would any living thing live if it could simply ignore hunger or pain, or worse still, actually like it, esp. hunger?  Such a species would quickly die out, and that is contrary to life itself.  That we are alive shows our nature as living beings in this regard: we are alive because we do that which allows us to live, and that includes finding ways to sate hunger, address our wounds, find mate(s), etc.  Living things that don't do that quickly die out.
"Suffering" (capital "S") is a different sort; it's "big-picture" kind of Suffering.  All living things suffer (small "s"), and Buddha taught that and lived it (well, he had no choice).  "Suffering" however is a choice.  When a being chooses to accept as stimulation (or input) any sensation, feeling, or thought and simply acknowledge it without attaching to it (i.e., without identifying with it as being part of itself instead of it being a mere interpretation of stimuli), it is then that Suffering is avoided.  There may still be suffering and that suffering is often a good thing to listen to: hungry?  Get some food.  Lonely?  Get some company.  In pain?  Get some help.  Lower-case "s" suffering thus is a very useful thing to have around.  The mistake people make is that they over-identify with it sometimes and mistake it for being a permanent or definitive part of themselves, when in fact, it's transient input (whether generated by external force, as with pain from a medical condition, or internally, as when someone seems overly focused on pessimistic ideas).  That is what Buddha taught: rising and falling, coming and going, it's all impermanent.  Life itself is included in it; you were not alive before this life (well, leaving aside reincarnation ideas, at least not alive as you are today), then you are alive, then you'll die one day.  So if you had never lived, it'd be all the same.  You had to be born some time, so why kvetch about the fact that life is limited in duration?  And if life has so much suffering in it, even for relatively well-off people such as those living middle-class or better lives in a first world country, why then would anyone really want to live forever?  But our instincts naturally incline us to desire life, since that is a valuable (and evolutionarily advantageous) instinct to have.  It impels us to defend ourselves against attack, get food, seek shelter, and weather all manner of hardships.  So this desire to live is hardly useless.  Yes, even Buddha had it.  He just knew what place it held in the scheme of things and so didn't let it rule the very life that desire existed to protect.
When once asked what he was: a god, a diva, or something else, he replied no to all of them.  He was then asked, well then, what are you?  His reply was simple: "Awake".  Well, for what that's worth, he was known for leaving people with answers that raised more questions than they answered.  But he never claimed (to the best of my knowledge) to be THE most supremely enlightened being to ever walk the face of the Earth, though a lot of other people have said that about him.  Hard to say if they are right but if Buddha himself never claimed it, then I wonder what makes others think that about him?  I'll say this about him: he got the whole all-is-impermanent thing down pretty good.  And teaching loads of people how to meditate was a pretty nice thing to have done, too.  So all in all, he was a pretty decent chap.  Perfect?  No.  No one is.  And perfect by whose standards, anyway?  I think he'd be the first to tell you that perfection is relative, and it is.
Comment: I stand corrected!  Thanks for informing me.
Comment: Buddha is very well respected as the perfect enlightened one for us Buddhists you know.
Comment: Re. your last paragraph, the Buddha is quoted as saying that he is supremely enlightened: for example, in the last verse of [Ariyapariyesana Sutta](http://www.accesstoinsight.org/tipitaka/mn/mn.026.than.html), "All-vanquishing, all-knowing", "I have no teacher, and one like me can't be found", "I, alone, am rightly self-awakened".
Comment: He only claims that one like him can't be found, which says nothing at all, since not a single thing can be found.


Which English phonemes are the easiest to distinguish from each other?

Question: I work as a literacy tutor in a preschool and part of my job is to help students develop phonological awareness by teaching them how to identify rhymes and alliteration. To make it as easy as possible for kids who are first learning I'd like to find the phonemes in English which are the easiest to tell apart. Not sure of the answer to this question I've been trying short (plosives) vs long (vowels and fricatives) phonemes, and voiced vs unvoiced phonemes. I'm also avoiding phonemes with the same tongue position (f/v, s/z). Does anybody have any information on this topic? Is there any research on the topic? Thanks.
Comment: A handout that may be useful (with an accompanying text that most American students, at least, will know by heart and ear) [is available here.](http://www.umich.edu/~jlawler/modestproposal.pdf)
Answer: Yes, there is a lot of research on phoneme confusability. Here is just one of many similar papers on the topic: Cutler, A., Weber, A., Smits, R., & Cooper, N. (2004). Patterns of English phoneme confusions by native and non-native listeners. The Journal of the Acoustical Society of America, 116(6), 3668-3678. The PDF is available at http://pubman.mpdl.mpg.de/pubman/item/escidoc:60592:2/component/escidoc:60593/Cutler_2004_patterns.pdf. You may find Table I and Table II helpful, specifically.


Where should a test server be hosted?

Question: Should a test server be hosted locally or on the internet ? What are the pros/cons? I have seen people do both.  What is best practice?
Answer: It should be hosted where everyone who needs to test can access it.
Important is that everyone can test in isolation, you don't want different processes or users interfering with each others tests runs.
As you tagged this question with "continuous integration" I would like to add that for automated tests I love to spin up a test environment from scratch so all the tests run 100% in isolation on a clean system. Automating the bootstrap of your environment with something like Vagrant could make this relatively easy.
In most cases you want to simulate your production environment as close as possible. As a manual tester you want to get the same feeling your end-clients are having. I think reporting on usability (including how smooth it feels) is just as important as finding functional defects. So hosting your test environment in the same datacenter and on similar hardware would make sense in this case.
Pro's for internet:

Easy access
Possible similar to end-users

Con's against internet:

Security
Latency
Answer: It really comes down to overall reliability and speed.
If you can guarantee that you have 24/7 access to your 'test server' via the Internet, with guaranteed > 10Mbps download/upload speeds, and you can protect 100% from external attacks (e.g. DoS) then the Internet might be the way to go.
But, if you are like most of the world that experiences inconsistent connections, periodic slow connections, etc, then an internal server might suit you better.
Additionally, if you are going to be doing things like fault injection then an internal server might be a better choice because you have greater control over it.
If you have 'protected' test data or other sensitive information that you don't want folks outside your org to potentially access then an internal server might be a better choice
If you want to emulate real users...use the same Internet services they use; don't attempt to emulate or simulate them by creating a mock service on the Internet.

Where should a test server be hosted?


Does an extension cord from 2 to 3 prongs have any benefits?

Question: If you're plugging a device with a 2-prong plug into an extension cord that has 3 prongs on the other end, does that give it the grounding benefit of the third prong?
Comment: It doesn't offer any electrical benefit, however I have used these before to be able to plug a grounded cable into an ungrounded cable(not really safe but it is useful for this function)
Answer: No. If the two prong device is fairly modern, it is sufficiently insulated in its design so that it does not need a separate grounding line (these devices were often referred to as double insulated). It means that the designer has ensured that it is highly unlikely that a consumer can come in contact with a hot lead in the device.
Many modern devices are polarized (one of the prongs is wider than the other) to ensure that the correct part of the device is connected to the hot side of the circuit. This helps ensure safety.
For all of these type devices, a two wire/prong extension cord is adequate, assuming it is rated for the wattage being drawn. This is a function of both the amperage of the tool and the length of the run.
When you plug a two prong device into a three prong extension cord, the device is not connected in any way to the ground wire in the cord.  There is no downside in this arrangement, but a two wire/prong extension would do the same thing.
There are older two prong devices that do not have adequate grounding and pose some risk if the device is damaged during use, for example some older metal bodied electric drills. Unfortunately, using a three wire extension will offer no greater protection when used with a two prong appliance.

While we are at it, let us rail against the three prong-to-two-prong adapter. These units are intended to allow you to plug a three prong device into an older  two prong outlet, and proper usage requires that you attach the grounding tab to the center screw in that outlet, bonding the adapter ground to the frame of the outlet body. This is often neglected. Much worse is the use of these adapters to connect a three prong device to a two wire/prong extension and no grounding is even attempted since none is possible. Even when used properly it may be "grounded" to an outlet that doesn't have a ground, and may actually be shorted to one of the current carrying conductors.
Throw these damn electrocution hazards away.
Answer: No. The two wires connected to the 2-prong plug get connected to the hot and neutral wires   in the extension cord. Since there is no connection to the ground in the extension cord, the 2-prong plug does not get the grounding benefit of the third prong.
Comment: I thought the neutral wire was for grounding and the hot wire for power.
Comment: Using the language from the NEC this answer is correct, Neutral is the grounded conductor it is the return path for the circuit. The grounding conductor is the 3rd prong for equipment grounding and is not used on a 2 wire cord.
Answer: Yes, the third prong provides a benefit.
A better quality power strip has a protection device that references ground.  This will prevent a high spike on either of the two remaining prongs:
http://electronicsbeliever.com/surge-protection-circuit-principle-design/

This will protect even two prong devices plugged into the surge protecting power strip.


What is the best way to clean internal lens elements?

Question: I've purchased old nikon ais lens on ebay. It was really cheap. Turns out it has some fungus growing inside. No worries, I take apart and clean. I used rubbing alcohol, 98% solution to clean it. Turns out it stripped some of the coating. I tried to clean with solution for glasses. But it leaves smudges and is not perfectly clean. Before I ruin another glass element, what solution is recommended for this use?
Answer: The coating was probably already damaged by the fungus, not the alcohol. Though you should consider using a lower concentration (70-90%) like a normal person.
PetaPixel: How to Remove Fungus from a Lens describes removing fungus by soaking the affected elements in an aqueous solution containing hydrogen peroxide and ammonia. After the fungus has been removed, the lens elements can be rinsed in distilled water and dried with a lint-free cloth before reassembly.
Answer: Some hints from someone who dabbled in it:
-Invest in some actually dust and lint free paper towels for drying things. It's good for your sanity.
-Contact lens lifters are very helpful in handling elements - but they tend to leave residue too.
-Alcohol-based (NOT soap based) eyeglass wipes aren't THAT bad if we aren't talking expensive or pristine lenses.
-You will need to clean multiple times to get all residues off.
-Make sure any particles of metal, glass, or stone are gone before doing any wiping on a glass element. They scratch everything to oblivion. Especially evil: metal filings clinging on or hiding in crevices after you had to drill or file to be able to attach a lens opener. Any cloth, q tip, wipe that potentially got contaminated with such particles you throw away.
Comment: Have you tried using lighter fluid? Few sources I found praise it for it's cleaning power
Comment: Tried Reinigungsbenzin - great for metal parts and aperture blades :)


How can I reuse LEGO part bags?

Question: I go through so many of these annoying plastic bags. Unfortunately, not many places recycle them. Are there any ways they can be re-sealed?
Comment: Scammers seem to be able to do this when they buy sets, remove the minifigs, reseal the bags and then return the box to the store for a full refund - so yes it must be possible. Add the info I just provided as a word of warning to those buying seemingly mint boxes with broken or suspicious seals.
Answer: One way of resealing the bags is to use a laminator. Most laminators aren't designed to seal anything other than lamination pouches so you'd want to be particularly careful using them to re-seal LEGO bags.

No matter how careful you are when you open them, most polybags tear slightly and leave rough edges that cannot be fed easily into a laminator.
I suggest cutting a straight line with scissors or a ruler/box cutter, just below the original seam.

Start up the laminator to get it warmed up and fill your polybag, I don't recommend you fill it up more than 1/2 or 2/3 of the bag as it can be difficult to feed the laminator.
Don't let it run too long as it will be quite difficult to remove (as shown in my example, I left it about a second too late, the second time I fed it into the laminator), it doesn't take a long time for it too seal completely and it takes a few tries to get it work well.
After the bag expands, it should be airtight and you can turn of the laminator, and remove it when it is safe to do so.
Comment: Along the same lines you could use a food vacuum sealer, they seal plastic bags, and on most the vacuum function can be bypassed.
Answer: Use a manual impulse sealer.  It consists of a linear heating element specifically for sealing bags in the fashion LEGO parts bags are sealed by the factory.  Narrow sealers can be purchased new online for as little as $12-15.  It's helpful that LEGO parts bags are relatively small.
I use these devices to reuse bags for various non-LEGO parts storage.  There is a dial on the front to adjust the heating cutoff.  Depending on the material and thickness a different heating time is needed to ensure a good seal without damaging the plastic.
Here's a video demonstrating its use: https://www.youtube.com/watch?v=iH-SbjYNzQc

How can I reuse LEGO part bags?


Is virus a concern running VMWare Fusion?

Question: Hi I have Macbook Pro running VMWare fusion, do I have to be concerned about viruses?
For example, if I have a trojan infected .exe key generator (legal for some reason), can I run it on the Mac without any problem?
Comment: +1 for not even trying to prove it's a legal keygen :P
Answer: You could use the virtual machine as a sandbox to execute programs that would make you nervous.  You are going to want to make sure that the guest is isolated from the host. If you are going to be executing malware and the like you probably do not want it using the network either.
Answer: In general, it's safe to run things in a Window Virtual Machine on the Mac.  The file system and application space are self contained.
Be careful not to share resources between the VM and the Mac.  You don't want the Windows machine to have access to the Mac's folders.
Of course, you can also run AntiVirus and Anti-Malware software inside of the VM.


Secure bookmark sync, "secure xmarks"?

Question: I'd like to use a bookmark manager, but I'd like my data to stay my own.  I happened to read about Xmarks ToS/use or what-have-you before checking out this site for recommendations, but I'm glad to see that people are pointing out that Xmarks will look through and aggregate your data (and other stuff).  In effect, I'd like Xmarks to take the model of Lastpass, their parent company, with my data.  Then I would send them my money.
I primarily use Firefox on Windows, but I also use Palemoon, Firefox on Android, and I'm experimenting with a few other Firefox forks and Linux.
Must have features

Firefox support
Bookmark management (CRUD)
Synchronization and/or backup
Pre-Internet encryption of data
Folder sorting
Tagging
Windows Support

Features I'd like to have

Cross browser support (ie Palemoon)
Mobile (Android) support
Free or low cost
Local database I can manage
Secure connection to the cloud

I came across Linkman, which has almost all of the features I am looking for, but I'm not so sure about the synchronization options.  I think SpiderOak would probably be the way to go, but I am hoping there's a software that does it all together.
Firefox Sync's ToS seem to be good:

Encrypted User Data
The Firefox Sync Service encrypts User Data on your computer and
  uploads encrypted User Data over the network using SSL communication.
  We believe that user privacy is important, and we require that the
  User Data is encrypted to reside on Mozilla's Firefox Sync Service
  servers. Those items you choose to synchronize across devices using
  Firefox Sync are examples of User Data that is designed to be
  encrypted before leaving your computer. These can include your
  browsing history, form history, bookmarks, saved passwords,
  preferences, and open tabs.

However, I don't like the direction that Firefox is headed.  They are trying to be Google Chrome in look and function, so I've started experimenting with other browsers.  Thankfully, many alternative browsers are forks of Firefox.  The most promising is Palemoon, and many extensions seem to work fine in it or have a fork from Palemoon.
Answer: I suggest Turtl. It is free, open source and client side encrypted. It is cross platform. It has both Firefox and Chrome extensions. Overall it is amazing.

Secure bookmark sync, "secure xmarks"?


Can I use an LGPL-licenced library in my commercial app?

Question: I want to use an LGPL-licensed library in my app for Microsoft's app marketplace.  Is that OK?
Comment: Also, keep in mind that you should NEVER EVER follow the legal advice that you get on the Internet, except if it comes from a lawyer. Preferably one who specializes in the given field, in this case: software licenses. So do take all these answers with a grain of salt, because otherwise you may be exposing yourself to lawsuits.
Comment: IANAL. The question is really do the terms of the MS App Marketplace and the LGPL conflict in any way? If the answer is "No" then it shouldn't be a problem. Otherwise it may be. Does the app marketplace prevent source distribution? Does the app marketplace forbid open source? [Edit]
More info from a quick google of the problem: http://social.msdn.microsoft.com/Forums/en/windowsphone7series/thread/edb9d5ca-d0ec-4004-ad7b-15a78072a386
Answer: Here is an encompassing answer:
https://web.archive.org/web/20220712000832/http://answers.google.com/answers/threadview/id/439136.html
In short: yes you can. But one important thing to take care of is that the GNU LGPL covered library is dynamically linked, not statically mixed with the main application.
It should also be possible to exchange that dynamically linked library for an independently compiled build. Otherwise you have likely intertwined the library and main application code.
Comment: > it's paramount to mention that software that statically links an LGPL library must be issued under an LGPL license itself, if I understand correctly
===>
Absolutely not. Any closed-source application can link statically with LGPL libs if it provides its object files to allow relinking with further / alternative versions of the LGPL library : http://www.gnu.org/licenses/gpl-faq.en.html#LGPLStaticVsDynamic
Comment: This is true for LGPL 2, but LGPL 3 seems to allow static linking if I understand it correctly.
Comment: What happens with header-only LGPL libraries?
Comment: @mario, so is it also allowed on a closed-source app? Am I required to give credit? Anything?
Comment: Please provide a plain English explanation of what a "GNU LGPL covered library [being] dynamically linked" means for a web app that uses a GNU LGPL covered library.
Comment: @RichardLeMesurier, both versions permit static linking, but it's paramount to mention that software that statically links an LGPL library must be issued under an LGPL license itself, if I understand correctly. I am not a lawyer. This shall not be construed as legal advice.
Comment: [What do 'statically linked' and 'dynamically linked' mean?](http://stackoverflow.com/a/311889/2441442). So having a dll file of a LGPL library in the filesystem would be ok?
Comment: Just as an example The [Adafruit_NeoPixel](https://github.com/adafruit/Adafruit_NeoPixel) library is LGPL3. Arduinos don't support dynamic linking in general. That would mean every LED project using this library needs to also be LGPL3. I'm pretty certain there are 10s of 1000s of projects in violation.
Comment: if I have independently compiled library (which is LGPL) in .so file in my Android app apk file than it's ok?
Answer: The LGPL license allows an application that references the binaries to remain closed-source. Also, there's nothing preventing you from selling an open source app on the Microsoft App Marketplace.
Comment: can you please mention, if i want to use LGPL code in close-source app, should I use separate `.dll` version (which will be available as separate file after user installs my app) or can i embed LGPL inside my `.exe` directly (just creating a way for users to "get the source code for that LGPL part" )?
Answer: This article may help.
I suspect that because LGPL allows making the source code (of the library that you linked to) available via a download, it must be OK to use an LGPL-licensed lib in your app for Microsoft's marketplace.
Quote from LGPL version 2.1:

If distribution of object code is made by offering access to copy
  from a designated place, then offering equivalent access to copy the
  source code from the same place satisfies the requirement to
  distribute the source code, even though third parties are not
  compelled to copy the source along with the object code.

The only thing that seems to be an issue is the "same place" requirement, which you will not be fulfilling if your app is being distributed via the marketplace.
Comment: Actually nothing stops you to bundle source code as resources in your app, say as a zip file and have some option to save it locally from your app if user wants to do so. Thing is if you have multiple libraries with different licenses you start losing track of what you need to do for each one


What is the optimal routine for overweight people, hypertrophy or strength training?

Question: I have been reading several threads and seems to be very confusing about overweight people who are trying to get back in shape (reducing weight+loosing fat+building muscles). Looks a lot to get all the three things at once but I am sure it can be achieved. Some says "Light weight and more reps to loose weight", some advice to "Lift heavy and less reps for loosing weight","Mix resistance and cardio for weight loss". They seems to be missing technical details.
What is the best(or better) from all of these, apart from a proper diet, healthy lifestyle and regular exercise.?
Answer: IMO it's addressing weak points and I'd lean towards strength training over hypertrophy (perhaps if only because it can be more psychologically rewarding seeing those beginner PRs improve rapidly) and maybe even some explosive training and high-intensity cardio and maybe even calisthenics (could include gymnastics). Besides that, at least a lot of natties seem to make more rapid gains adopting a considerable strength component to their training instead of focusing exclusively on hypertrophy.
I really think people focus too much on how many calories they burn doing a particular physical activity. The way I see it is that you start gradually raising your long-term energy expenditure by just becoming a more active, strong, energetic individual even when you aren't training.
And addressing weak points can do that. It might make the difference between taking the elevator just to get to the second floor when you're late for work to having the strength, coordination, and energy to fly up the stairs to the top floor just because you feel like it. It might make the difference between choosing the path of least resistance to push something heavy around versus deadlifting it and happily carrying it around. It might make the difference between just sitting on the grass or wanting to do cartwheels.
So I see it like that. Find a way to boost your energy expenditure not just through training, but throughout your entire day. I even think skill-oriented training like learning how to do a handstand can help since that can make it more fun to practice those skills all the time throughout the day.
Answer: Endurance training is best to lose weight. I would mix cardio with higher rep workouts.
The cardio is where you will burn most of the calories to lose weight, with the high rep exercises giving you more muscle tone. I would aim for 8-12 reps per set.
Most important is a good healthy diet. I know some people that have lost 15-20 lbs just from cutting pop out of their diet!
Comment: Would this endurance help in getting muscles definition or in other words would it give a nice definition to my muscles? For example, Arms, and shoulders muscles?
Comment: Yes it will definitely help. Muscle definition won't show without lowering bodyfat %. HIT is probably best to burn calories, but starting with regular cardio is good too.
Answer: For weight loss - diet gives much better result then training.
In this matter - exercises have two kinds of benefits:

they speed your metabolism, so your body tends to use more energy,
directly burns energy.

For first heavy weight is OK. High weight triggers more testosterone - for instance. Bigger white-fiber muscles needs more energy during the day.
To burn more - many, many reps with high intensity goes better. Like running, rowing.
Note that there are potential problems with both of ways. Your weight can bring much higher effort to your body. For instance - your knees can get injured. Heavy weight, if done wrongly... can be also a problem. If your body is warmed they you can miss signals your body is sending.
So what is better? I would do both. Use light weight for warm-up - at start of training some walking/running or interval of both. Then before main set, you can do warm-up set lighter, more reps, and after that go with higher weights in main exercise. Usually people do one, two complex exercises + support them with accessory training. Accessory means here - isolated, targeting particular muscle. For them, if you have short rests no warm-up is needed. At the end you can run/walk on treadmill for 30+ min. find out proper heart rate and stick to it for that time. Not always more is better...
Comment: Thats quite right,but in this process do I burn more fat also, as the weight loss could come to a threshold, the thing is I want to look leaner not thing or weak.
Comment: I like weight. So my answers here are based. Also I like to exercise in different ways. For me that is a lot between two options you presented. Question is about your BMI - if that is around 30, or you have problems with knees - then, perhaps running is not a good choice. I would do weight training + some exercises with constant heart bit - for faster fat lose. I have a gym-friend who do 1000calories each training. 3-4 machines, and that works for him.
Comment: There are many options. Hard to tell what can work in your case. Try them, talk with people, find trainer. That way you can get better informed. I know that at start that is a bit messy. And you want simple rules - do this, do not do that. Personal trainer helps here. However I like to build up my own knowledge - takes time, but... that is my way.
Answer: Assuming that you might be relatively new to the game, if you do body building workouts you will be doing enough reps (12) at a light enough weight to not get hurt, and you will see some noticeable hypertrophy. After a few months of that, you can start doing higher intensity low rep (3 to 5) workouts with good form, and survive it.
As far as weight loss and muscle definition, its just a matter of percentage of body fat. For what its worth, I recommend you to be patient. You burn off more fat by just 'digesting food and thinking' than by your, maybe, 600 Calorie workout (even counting the "after burn"), so eat wisely, hydrate, and get lots of sleep, and you will lose weight. Some people store more peripheral sub-cutaneous fat in their limbs than others, and so the muscle cut might be harder to come by.
Answer: Assuming that you (or other visitors here) might be relatively new to the game, if you do body building workouts you will be doing enough reps (12) at a light enough weight to not get hurt, and you will see some noticeable hypertrophy. After a few months of that, you can start doing higher intensity low rep (3 to 5) workouts with good form, and survive it.
As far as weight loss and muscle definition, its just a matter of percentage of body fat. For what its worth, I recommend you to be patient. You burn off more fat by just 'digesting food and thinking' than by your, maybe, 600 Calorie workout (even counting the "after burn"), so eat wisely, hydrate, and get lots of sleep, and you will lose weight. Some people store more peripheral sub-cutaneous fat in their limbs than others, and so the muscle cut might be harder to come by. Lipolysis (fat mobilization) occurs in moderate intensity exercise as per https://www.hindawi.com/journals/jobe/2015/473430/    The jury is still out as how that mobilization of fat gets involved in exercise fat burning, or post exercise fat storage. I'm convinced that body building resistance training will utilize intramuscular fat that, in turn, gets replaced by some of the fatty acids in the blood that are mobilized during the workout (unless you spike your insulin with carbs before the workout). There are a million journal articles that present the spectrum of "how to lose fat" recommendations via exercise or by diet, so I hesitate to start an avalanche of competing citations here.
Answer: 1 - Congrats on your decision to get healthy.
2 - The great news your just getting started so essentially anyway you slice it you'll lose weight and put on muscle.
The specialized programs are what you'll work up to and nothing you need to concern yourself now.

For the Most Efficient Results

I would do circuit training using just a standard 3x10 with 60-90 seconds per rest. I had a friend win his "weight loss" office pool doing literally this workout.
Get accustomed to the machines, early on -- focus on intensity and depending on how big your gym is do all the machines on a M, W, F schedule.
I know it seems strange but as long as your workouts are intense you only need to like for 20-30 min.
I'd skip "pure" cardio (unless you want to come in on a Sat or Sun).

Your goal now is to get your feet wet, it's a common to want to do too much and that leads to only one road - please don't fall into that trap.


Schengen Visa Application: Academic Conference

Question: I am travelling to Portugal from India to attend an academic conference where I will be presenting a paper. I am an undergraduate student and not employed (or receiving payment for attending this conference). Should I apply under Business category or Tourist Category?
Answer: If your sole purpose in making the journey to Portugal is to present a paper at an academic conference, then you would indicate 'Business'.  To assure that your application is treated as a genuine business visitor, your proposed travel dates should not extend wildly beyond the overall conference dates.  They will also be looking for something that connects your programme of study to the conference topics and you may wish to include something explicit as evidence (it's optional but may help).
You can include the conference details and your spot on the conference proceedings as supporting evidence along with all the other evidence needed to support your application.
There's some generic information on Schengen applications here: Schengen Visa Application: tips for preparing


Launch apps full screen

Question: I quite like using full-screen apps on OSX Mavericks (Safari, iTunes, Mail, etc).  I'd like all apps that are capable of running full-screen to launch in full-screen mode automatically, instead of me having to press Ctrl-Cmd-F each time, is that possible?
Comment: My apps always launch in full screen, if I hadn't closed all windows last time I quit them.
Comment: I'm not quite sure about it but I'd an old iMac which saw different OS X versions. When that iMac first met with full-screen apps, apps always started full-screen when closed like that and still does on Mavericks. But on my newer MacBook Air, which I acquired with Mountain Lion and then upgraded to Mavericks, it doesn't happen like that. Therefore, I happen to believe that it's an old preference on my iMac which can't be replicated on newer models.
Comment: This is a big problem. Many apps will re-open in full screen if quitted full screen. Safari does not. Chrome does not. There is a Chrome hack that does it, but I can't find any way to do it in Safari. Anyone got more info for this question?
Comment: A bit of a follow up - this seems to work when using iTunes, but not with the Calendar App, Pages, Etc.
Answer: You can use automator to create an application that will launch the application that you want to open in full screen and run an apple script. The script can perform a keystroke to run the shortcut for full screen.
Launch Automator, Choose Application, Drag "Launch Application" from library and choose desired app, Drag "Apple Script" from library, enter apple script (check with specific app for correct keystroke), this works for chrome
here is the script for google chrome fullscreen app:
on run {input, parameters}
    tell application "Google Chrome" to activate
    delay 2
tell application "System Events"
    keystroke "f" using {command down, control down}
end tell

Screenshot
[
Link with tutorial to create Automator Full screen application
https://youtu.be/5L5ikafzCzI
Answer: I realized the answer to this question well long after I had the problem. I kept trying to use several work arounds until I realized that feature hadn't been removed, but rather rolled into a different set of features.
Most full-screen apps don't remain open because it's a type of window state. By default, under General, the setting "Close windows when quitting an app" is turned on, which means the window you have saved will be closed and return to it's default state.
To retain full-screen, or your previous window preferences, you need to turn off this setting!
Comment: thanks, this helped with a few apps, though not all
Comment: Thank you so much! I had no idea that that was even  off. There were several settings in that pane that I thought I had changed. Thanks again!
Answer: I called Mac support about the issue, and it seems in Yosemite this feature has been since removed in general. However there are some apps that still function this way. One of them being iTunes (which opens in full screen mode).
It was suggested, to get the functionality of a full screen app, after quitting, is to assign an app to a new desktop, and maximize it (press the option key + clicking on green). It will always open that desktop in full screen.
Answer:  set MyApps to {"Google Chrome", "Skype", "Finder"}
repeat with MyApp in MyApps
    tell application MyApp
        activate
        delay 3
    end tell
    tell application "System Events"
        tell process MyApp
            set value of attribute "AXFullScreen" of window 1 to true
            delay 3
        end tell
    end tell
end repeat

Comment: Thanks for formatting the code! Good use of AppleScript - perhaps explain how a new user would get that code to run (or better link to osxautomation / apple help on Script Editor)

Launch apps full screen


Using an old laptop keyboard with Raspberry Pi

Question: I have an old laptop keyboard like the one shown below:

It has a 24-wire flat cable coming out of the back. Would it be possible to use this as a keyboard for the Pi (I assume with some microcontroller in between)?
Comment: I don't know for that one in particular, but I do know that it is possible to modify a some laptop touchpads to work with regular ps/2 without any active extra circuitry.
Comment: http://www.grynx.com/projects/converted-laptop-keyboard/ might interest you.
Comment: Possible, probably, but if you need to ask, you most likely do not have the skills to do it.  I would suggest a cheap USB-keyboard.
Comment: http://www.farnell.com/datasheets/79209.pdf
check this out you can get them from $2
Answer: There is no easy or simple way to achieve what you ask.
The simplest answer is just ignore this keyboard and get a USB one.
However, if you really want to do it, it's a DIY job through and through. Your solution will be custom to this keyboard and may or may not be easily adapted to accommodate keyboards from other manufacturers.
Laptop keyboard connectors are not standard. They vary across manufacturers. Typically, they also lack any electronics to process the keypresses and convert them into simpler data messages, e.g. key codes or button codes etc.
Therefore, first you need to figure out what happens each time you press a key, i.e. which electrical signals get activated (get shorted together).
Then you have two options, both very tricky:
Option 1 - Very advanced:
You need to construct an electronic interface which will connect between the keyboard and the USB port on the Pi. It needs a microcontroller to emulate a USB keyboard when it's plugged into the USB port and you will need to write software to map the key pressing signals into USB keyboard presses. The microcontroller needs to do all the work. You might want to read this related question: Can I make a full USB keyboard with Makey Makey + Raspberry Pi
Option 2 - Insanely advanced:
Raspberry Pi has a connector with 17 GPIO (general purpose input output) pins. You need to design a circuit to reduce the 24 keyboard lines and interface them to the GPIO pins. Then you need a custom keyboard driver for the Pi operating system.
Hint:
Some of the 24 connector lines will be inputs and others outputs. Each time a key is pressed, some of the inputs connect to some of the outputs. Some of the lines may be unused. It will take patience and a continuity checker to figure out exactly what happens. Also consider searching for keyboard encoder chips. This is an example: http://www.ti.com/product/tca8418e These chips take out the hard work of encoding.
Comment: Basically, it's probably impossible... =P
Answer: Sorry to reply to such an old thread, but you can achieve this with an old USB keyboard controller.
I haven't tried it yet, but I believe this should be possible. Simply line up the connectors on the ribbon cable with those of the keyboard controller and hold it in place with the cap (make sure it has the same amount of connectors, it usually does). If the ribbon cable is too small, get an adapter.
Answer: I have few laptop keyboards and I really want to use them... So what I can see those with 24 wires are keyboards without numeric pad while keyboards with numeric pads have 26 wires.
I have torn down one broken keyboard to see how it is made.
From what I have seen there are two sheets of foil with paths and connection/button points divided with one foil as a separator. Each wire is allocated to few buttons on one sheet and connects to the second sheet and other wire. I have checked the number of available combinations https://www.hackmath.net/en/calculator/combinations-and-permutations?n=24&k=2&order=0&repeat=0 look's like we have 276 possible combinations.
Because there are many keyboards and they have different combinations best way is to make a small program that asks you to press a specific button and record which wire-wire combination is associated with that button.
Since Rpi has only 17GPIO as Vassilis mentioned it will be hard to do it because you need something in between, but there is Arduino (Mega = 54 IO)and it can help at least to decode button/wire pair combination. I need to look on laptop boards what ic are used as the controller to see if we can use it, is it programmable etc.
Anyway, it is possible and probably not that hard but of course normal people would just buy a USB keyboard.
Answer: I used a Teensy ++2.0 as a keyboard controller for a Sony Vaio that I converted to a Raspberry Pi Laptop. An ohm meter was used to figure out the key matrix and Teensyduino code was written to scan the matrix and send the key codes over USB. The Teensy also controls the touchpad over PS/2 and sends the results over the same USB cable.
Using an ohm meter to figure out which signals on the keyboard cable are connected is very time consuming and prone to error (you need 3 hands, good eyes, and a lot of time). To make it easier for people to re-use a laptop keyboard, I wrote an Instructable that describes the step by step process to build a keyboard controller using a Teensy LC or 3.2. The Teensy is first loaded with a routine that reports which pins are connected when a key is pressed. From this, you can build a key matrix table that can be added to a new Teensy routine that acts as a keyboard USB controller. I have converted over a dozen laptop keyboards to USB using this method. You will need to send my Eagle board file to OSH Park to have the circuit board fabricated. The board provides pads to solder a keyboard connector that is routed to a Teensy microcontroller. This project is definitely more advanced than your basic plug and play Arduino project but it's worth the effort if you want to re-purpose an old laptop with a Pi and keep the original keyboard and touchpad.
Comment: If I remember correctly, a Teensy costs around $20, so unless the OP is really interested in the keyboard more than in the RPi, buying a new keyboard would save both time and money.
Comment: Assuming OP wants to build a cyberdeck or laptop, the form factor is probably the reason. Its very hard to find a USB keyboard as nice and compact as a laptop keyboard.
Answer: Some keyboards might have a controller of some sort. If they don't have a controller, then all of the keys are wired up in a key matrix. Pushing a key will connect one column and one row together. Most controllers will scan through the columns and look to see what rows go high to find which keys are pressed. One thing you might try is getting a Teensy arduino and programming it with the usb keyboard firmware. You'll have to figure out how all of the keys are wired up though. The Teensy can convert it to USB to plug into the Pi. There's a lot of technical skill required to do this, it's not for the faint of heart.
Comment: By the looks of the flex cable I bet it's a key matrix.


Can a Scrum Master be the Product Owner in Scrum?

Question: I would like to know if a Scrum Master can be the Product Owner in Scrum?
Comment: Also, Erin's answer in this post nails this question (with a fancy draw) -> http://pm.stackexchange.com/questions/4707/why-cant-the-scrum-master-and-the-project-manager-be-the-same-person/4717#4717
Answer: It is possible, but not recommended by most experts I know of, as these two have conflicting roles and responsibilities. PO is focusing on getting the most bang for the bucks, while the role of SM is to help the team get to and maintain its full potential in the long term. This includes shielding the team from external discruptions and ensuring they get only as much work as they can handle.
So the PO is continually pushing the team to deliver more value, while the SM is pushing back to avoid overloading the team. If these two roles are being handled by the same person, one side usually wins over the other, resulting in imbalance.
Mike Cohn explains this with a nice historical example in his blog.
This question was also asked on Programmers.SE.
Comment: @Wivani, even though combining the two roles is likely to cause trouble down the line in general, it *might* work out under some circumstances, for some personalities, for some time. I have seen it working myself on a project. So never say never :-)
Comment: Conflicting roles and responsibilities: for that reason I would answer the question of OP with 'If you don't mind not calling your methodology Scrum, and you have no problem with the person having those 2 roles becoming schizophrenic, go right ahead'.
Comment: Point taken. I would definitely not see it work in my current work situation (I am scrummaster); probably a certain set of variables is making it impossible. Not the least the fact we're in early adoption of Agile/Scrum.
Answer: From Jeff Sutherland and Ken Schwaber's Scrum Guide (https://www.scrum.org/Portals/0/Documents/Scrum%20Guides/Scrum_Guide.pdf)
The product owner has a specific responsibility to give the team work:
"No one is allowed to tell the  Development Team to work from a different set of requirements, and the Development Team isn't allowed to act on what anyone else says."
...and the Scrum Master has a specific responsibility to coach and guide (see the sections on the Scrum Master's responsibilities).
I'd add that even where the team and Product Owner do not operate in any sort of conflict, part of the Scrum Master's responsibilities include coaching the Product Owner. One can self-coach, but it's often more effective to have someone else in that role.
Answer: Normally, it is not recommended. Especially because sometimes, PO is the one introducing disturbance within the sprint with "always-super-urgent" issues, and SM is supposed to hold them off as long as possible. SM in this case has to use his negotiation skills on the PO and the stakeholders to keep the sprint disturbances as much as possible.
That being said, I did come across one scenario where I played the role of Scrum Master and "mirrored" the Product Owner.
This was due to the team being a distributed one (Offshore with 4 hours of time difference), where the development team was on one end together with me, and the PO was on the other end.
I had several one-on-one talks with the PO to have much better understanding of the product, and also various satellite issues revolving around the product, which helped in answering most of the team's questions when the PO was not directly reachable.


Calendar reminder does not work

Question: On elementary OS 5.1 Hera,when I configure a reminder in Calendar, it does not register. How can I fix this problem. I have not found any solution so far. Thank you.
Answer: Unfortunately this is a known issue: (https://github.com/elementary/calendar/issues/459, https://github.com/elementary/calendar/issues/469, https://github.com/elementary/calendar/issues/474).
Edit: This should fix it: https://github.com/elementary/calendar/pull/481, hopefully it will be merged and then the fix will be provided in an update.

Calendar reminder does not work


How and why do normalization and feature scaling work?

Question: I see that lots of machine learning algorithms work better with mean cancellation and covariance equalization. For example, Neural Networks tend to converge faster, and K-Means generally gives better clustering with pre-processed features. I do not see the intuition behind these pre-processing steps lead to improved performance. Can someone explain this me?
Comment: I am finishing Geoffrey Hinton's Neural Networks for Machine Learning on Coursera, and he explains this in lecture 6b: "A bag of tricks for mini-batch gradient descent." You can preview the video without signing up or signing in.
Answer: It is true that preprocessing in machine learning is somewhat a very black art. It is not written down in papers a lot why several preprocessing steps are essential to make it work. I am also not sure if it is understood in every case. To make things more complicated, it depends heavily on the method you use and also on the  problem domain.
Some methods e.g. are affine transformation invariant. If you have a neural network and just apply an affine transformation to your data, the network does not lose or gain anything in theory. In practice, however, a neural network works best if the inputs are centered and white. That means that their covariance is diagonal and the mean is the zero vector. Why does it improve things? It is only because the optimisation of the neural net works more gracefully, since the hidden activation functions don't saturate that fast and thus do not give you near zero gradients early on in learning.
Other methods, e.g. K-Means, might give you totally different solutions depending on the preprocessing. This is because an affine transformation implies a change in the metric space: the Euclidean distance btw two samples will be different after that transformation.
At the end of the day, you want to understand what you are doing to the data. E.g. whitening in computer vision and sample wise normalization is something that the human brain does as well in its vision pipeline.
Comment: Do you have a reference regarding whitening and normalization in the human brain?
Answer: It's simply a case of getting all your data on the same scale: if the scales for different features are wildly different, this can have a knock-on effect on your ability to learn (depending on what methods you're using to do it). Ensuring standardised feature values implicitly weights all features equally in their representation.
Comment: This is not really a good explanation. To achieve true understanding you need to go at least a level deeper in explanation.
Comment: what do you mean by " this can have a knock-on effect on your ability to learn", maybe you could expand on this?
Comment: I agree with Zelphir; this answer sounds like an answer, but doesn't provide any additional information beyond "weights all features equally." The natural next question is "why is it important to weight all features equally?"
Comment: i need  any reference to my thesis please
Answer: Some ideas, references and plots on why input normalization can be useful for ANN and k-means:
K-means:

K-means clustering is "isotropic" in all directions of space and
  therefore tends to produce more or less round (rather than elongated)
  clusters. In this situation leaving variances unequal is equivalent to
  putting more weight on variables with smaller variance.

Example in Matlab:
<code>X = [randn(100,2)+ones(100,2);...
     randn(100,2)-ones(100,2)];

% Introduce denormalization
% X(:, 2) = X(:, 2) * 1000 + 500;

opts = statset('Display','final');

[idx,ctrs] = kmeans(X,2,...
                    'Distance','city',...
                    'Replicates',5,...
                    'Options',opts);

plot(X(idx==1,1),X(idx==1,2),'r.','MarkerSize',12)
hold on
plot(X(idx==2,1),X(idx==2,2),'b.','MarkerSize',12)
plot(ctrs(:,1),ctrs(:,2),'kx',...
     'MarkerSize',12,'LineWidth',2)
plot(ctrs(:,1),ctrs(:,2),'ko',...
     'MarkerSize',12,'LineWidth',2)
legend('Cluster 1','Cluster 2','Centroids',...
       'Location','NW')
title('K-means with normalization')
</code>

(FYI: How can I detect if my dataset is clustered or unclustered (i.e. forming one single cluster)
Distributed clustering:

The comparative analysis shows that the distributed clustering results
  depend on the type of normalization procedure.

Artificial neural network (inputs):

If the input variables are combined linearly, as in an MLP, then it is
  rarely strictly necessary to standardize the inputs, at least in
  theory. The reason is that any rescaling of an input vector can be
  effectively undone by changing the corresponding weights and biases,
  leaving you with the exact same outputs as you had before. However,
  there are a variety of practical reasons why standardizing the inputs
  can make training faster and reduce the chances of getting stuck in
  local optima. Also, weight decay and Bayesian estimation can be done
  more conveniently with standardized inputs.

Artificial neural network (inputs/outputs)

Should you do any of these things to your data? The answer is, it
  depends.
Standardizing either input or target variables tends to make the training
  process better behaved by improving the numerical condition (see
  ftp://ftp.sas.com/pub/neural/illcond/illcond.html) of the optimization
  problem and ensuring that various default values involved in
  initialization and termination are appropriate. Standardizing targets
  can also affect the objective function.
Standardization of cases should be approached with caution because it
  discards information. If that information is irrelevant, then
  standardizing cases can be quite helpful. If that information is
  important, then standardizing cases can be disastrous.

Interestingly, changing the measurement units may even lead one to see a very different clustering structure: Kaufman, Leonard, and Peter J. Rousseeuw.. "Finding groups in data: An introduction to cluster analysis." (2005).

In some applications, changing the measurement units may even lead one
  to see a very different clustering structure. For example, the age (in
  years) and height (in centimeters) of four imaginary people are given
  in Table 3 and plotted in Figure 3. It appears that {A, B ) and { C,
  0) are two well-separated clusters. On the other hand, when height is
  expressed in feet one obtains Table 4 and Figure 4, where the obvious
  clusters are now {A, C} and { B, D}. This partition is completely
  different from the first because each subject has received another
  companion. (Figure 4 would have been flattened even more if age had
  been measured in days.)
To avoid this dependence on the choice of measurement units, one has
  the option of  standardizing the data. This converts the original
  measurements to unitless variables.

Kaufman et al. continues with some interesting considerations (page 11):

From a philosophical point of view, standardization does not really
  solve the problem. Indeed, the choice of measurement units gives rise
  to relative weights of the variables. Expressing a variable in smaller
  units will lead to a larger range for that variable, which will then
  have a large effect on the resulting structure. On the other hand, by
  standardizing one attempts to give all variables an equal weight, in
  the hope of achieving objectivity. As such, it may be used by a
  practitioner who possesses no prior knowledge. However, it may well be
  that some variables are intrinsically more important than others in a
  particular application, and then the assignment of weights should be
  based on subject-matter knowledge (see, e.g., Abrahamowicz, 1985). On
  the other hand, there have been attempts to devise clustering
  techniques that are independent of the scale of the variables
  (Friedman and Rubin, 1967). The proposal of Hardy and Rasson (1982) is
  to search for a partition that minimizes the total volume of the
  convex hulls of the clusters. In principle such a method is invariant
  with respect to linear transformations of the data, but unfortunately
  no algorithm exists for its implementation (except for an
  approximation that is restricted to two dimensions). Therefore, the
  dilemma of standardization appears unavoidable at present and the
  programs described in this book leave the choice up to the user.
Answer: There are two separate issues:
a) learning the right function
eg k-means: the input scale basically specifies the similarity, so the clusters found depend on the scaling.
regularisation - eg l2 weights regularisation - you assume each weight should be "equally small"- if your data are not scaled "appropriately" this will not be the case
b) optimisation , namely by gradient descent ( eg most neural networks). For gradient descent, you need to choose the learning rate...but a good learning rate ( at least on 1st hidden layer) depends on the input scaling : small [relevant] inputs will typically require larger weights, so you would like larger learning rate for those weight ( to get there faster), and v.v for large inputs... since you only want to use a single learning rate, you rescale your inputs.  ( and whitening ie decorellating is also important for the same reason)
Answer: Why does feature scaling work? I can give you an example (from Quora)

Let me answer this from general ML perspective and not only neural networks. When you collect data and extract features, many times the data is collected on different scales. For example, the age of employees in a company may be between 21-70 years, the size of the house they live is 500-5000 Sq feet and their salaries may range from $30000-$80000. In this situation if you use a simple Euclidean metric, the age feature will not play any role because it is several order smaller than other features. However, it may contain some important information that may be useful for the task. Here, you may want to normalize the features independently to the same scale, say [0,1], so they contribute equally while computing the distance.
Comment: If you're citing a post from Quora, you really need to link to the source.
Comment: [Source](https://www.quora.com/When-should-you-perform-feature-scaling-and-mean-normalization-on-the-given-data-What-are-the-advantages-of-these-techniques/answer/Shehroz-Khan-2)
Answer: Pre-processing often works because it does remove features of the data which are not related to the classification problem you are trying solve. Think for instance about classifying sound data from different speakers. Fluctuations in loudness (amplitude) might be irrelevant, whereas the frequency spectrum is the really relevant aspect. So in this case, normalizing amplitude will be really helpful for most ML algorithms, because it removes an aspect of the data that is irrelevant and would cause a neural network to overfit to spurious patterns.
Answer: This paper is talks only about k-means, but it explains and proves the requirement of data preprocessing quite nicely.

Standardization is the central
  preprocessing step in data mining, to standardize values of features or attributes from different dynamic range into a
  specific range. In this paper, we have analyzed the performances of the three standardization methods on
  conventional K-means algorithm. By comparing the results on infectious diseases datasets, it was found that the
  result obtained by the z-score standardization method is more effective and efficient than min-max and decimal
  scaling standardization methods.

.

... if there
  are some features, with a large size or great variability,
  these kind of features will strongly affect the clustering
  result. In this case, data standardization would be an
  important preprocessing task to scale or control the
  variability of the datasets.

.

... the features need to be dimensionless
  since the numerical values of the ranges of dimensional
  features rely upon the units of measurements and,
  hence, a selection of the units of measurements may
  significantly alter the outcomes of clustering.
  Therefore, one should not employ distance measures
  like the Euclidean distance without having
  normalization of the data sets

Source: http://maxwellsci.com/print/rjaset/v6-3299-3303.pdf
Answer: I think that this is done simply so that the feature with a larger value does not overshadow the effects of the feature with a smaller value when learning a classifier . This becomes particularly important if the feature with smaller values actually contributes to class separability .The classifiers like logistic regression would have difficulty learning the decision boundary, for example if it exists at micro level of a feature and we have other features of the order of millions .Also helps the algorithm to converge better . Therefore we don't take any chances when coding these into our algorithms. Its much easier for a classifier, to learn the contributions (weights) of features this way. Also true for K means when using euclidean norms (confusion because of scale). Some algorithms can work without normalizing also.


how is the value of crypto coin decided

Question: Can any one help me with required information how a newly created coin value is assigned ? and how does the rate fluctuations occur
Answer: The market decides. If people can obtain the coin easily themselves then they will mine it rather than buying it on an exchange.
But the coin needs a use, function, purpose or reason for people to have the coin.
Basic supply and demand. If people do not buy the coin at a high price then the price gets lowered to see where people might consider buying it.
Crypto coins generators realized this and tried to tweak the parameters on the coins so that rewards are high at the start, a fast rising difficulty make the coin look rare and highly sought after, in reality the coin has just been pumped ready to dump

how is the value of crypto coin decided