Why did Coriolanus Snow lose the war?

Question: I haven't read the book. From the movie, it seemed like his downfall was swift. Was his military inferior? How is that possible with all the peacekeepers we see. There are a lot of them and they are better equipped. How did Snow lose the battle in the air? Was the integrity of the Capitol completely dependent on the resources from the districts? Was that the cause?
Answer: At the start of the books, the Snow regime has pretty much absolute control. However, as revealed in the last book, there exists a free District 13, which according to propaganda was completely destroyed after the First rebellion 75 years ago (the one that lead to the founding of the Hunger Games).
However, District 13 was never destroyed. This district had a lot of the nuclear research and so they had access to nuclear weapons after rebelling. This enabled them to make a non-aggression pact with the regime, since neither side could risk a nuclear war. And ever since they made this pact, they have been focusing on building up a military, most notably a strong air force.
Katniss' defiance in the first and second books starts an open rebellion in all districts, meaning all-out civil war. Broadcasted rebel propaganda in the third book fuels this further. As we can see from numerous civil wars in the real world, it isn't easy for a dictator to wage a civil war against their own population.
The scale of the rebellion itself is what wins the war. It simply grew too large to contain.
After the first book, only District 11 rebelled and this rebellion was crushed. It's not until Katniss blows up the Hunger Games arena itself in the second book that the full-scaled rebellion breaks out everywhere.
District 11 was the major food supplier district. The capital was far from self-sufficient, so losing access to various resources in the different districts must have been a blow. We don't know at what extent though, since details are scarce about what goes on in the other districts.
District 13 also tries to coordinate the various rebelling groups and evacuate them to join the larger war effort. The exact location of District's 13 base wasn't known by the government, so they fail to bomb it, as was done to District 12. And then their air superiority didn't mean as much. In the end, any war must be won on the ground.
Eventually the rebels manage to tilt the war in their favour by gaining control of District 2 which held most of the government military command, basically taking over the main military staging area. After that, the war quickly tilts in favour of the rebels and they push towards the capital.
Answer: Propaganda. The rebels bombed and slaughtered Capitol children as they were being sent to take refuge on Snow's estate, and made it appear that Snow had ordered the massacre himself. Even the military turned against him at that point.
Comment: This isn't why Snow lost the war, using civilians as human shields was just his last desperate attempt to protect himself and the palace. The war was already lost at that point.
Comment: I think the OP is referring to how the war eventually turned against Snow. With all the military might the Capitol had, how did they lose control of the districts to the rebels who at best had a few guns and and old D13 bunker that Snow eventually bombed.
Comment: Id say this his answer still holds true. Most of the districts all rose up and fought back against the capital with the most notable exception being district 2 where they get the peacekeepers from. Which was why it was so hard to take in the book.
Comment: Propaganda was definitely why, it's one of the main themes of the books. And until the rebels killed Capitol children, including Prim, and made it seem like Snow ordered it, the war was still at best a toss-up. It was that act that turned both sides against him. That's the only "swift" part. But otherwise yes, District 13 had nuclear and air capabilities that rivaled the Capitol, and the Districts were mostly starving and in open rebellion and had taken local control. As Snow and Katniss had agreed, the Capitol's grip on Panem was always fragile.
Answer: The Capitol is completely dependent on districts for survival. The winning point for the rebels came when they destroyed the Nut (Capitol's military headquarters) in District 2, which was literally the winning move of the war.
At that point, the Capitol's war effort was doomed; there was no chance of a Capitol victory by then. The bombing of the Nut destroyed the Capitol's air force, logistical capabilities, and killed large numbers of Peacekeepers and loyalist soldiers. The Capitol had no more military might after this, other than a few infantry soldiers who were outnumbered and outgunned by the rebels in the 13 districts.
Remember, the rebels were backed by the politically independent District 13, which had its own arsenal of guns, ammunition, special weaponry, planes, and its own army/air force. With the support of District 13, the rebels would easily outgun the Capitol and loyalists.
In the film (Mockingjay Part 2), after the bombing of the Nut, Snow admits during a banquet scene with his staff that the war was lost, and that they had no more hope of winning.

Why did Coriolanus Snow lose the war?


Amount of possible disjoint transpositions in $A_n$ and $S_n$

Question: How can I show that the amount of possible products of disjoint transpositions in $S_n$ is strictly more than two times the amount of possible products of even number of disjoint transpositions in $A_n$ for every $n>3$?
Answer: The possible products of disjoint transpositions straightly correspond to collection of disjoint couples of $\{1,2,...,n\}$. To form $k$ couples ($k\le n/2$) can be done in
$$ T_{n,k}:= \frac{\overbrace{\binom n2 \binom{n-2}2 \ldots \binom{n-2k+2}2}^k}{k!}$$
ways.
This can also be written as
$$T_{n,k} = \binom n{2k}\cdot\frac{(2k)!}{k!}\cdot \frac1{2^k} = \binom n{2k}\cdot (2k-1)(2k-3)\ldots\cdot3\cdot 1$$
Probably this helps.


Steel (531) road bike conversion to disc practicability

Question: Are the stays on an old PX-10 frame (531) sturdy enough for disc brakes? I ask this, because this frame has nice, wide stays for wide rims and tires for use as a bad-weather bike. I would consider having disc mounts brazed on if I knew the stays could withstand the forces.
Comment: You're just doing rear disc brakes? The front will stay rim? Because the front brakes do at least 75-100% of your braking. If you're going to go disc, change your forks.
Comment: Even if they stays weren't strong enough, you could just replace those two. But really, what's the point for a bad-weather bike. Just use rim brakes, or get a different frame. Rim brakes have worked sufficiently well for a hundred years.
Comment: The frame question is a duplicate of at least three others, starting http://bicycles.stackexchange.com/questions/37227/convert-a-cannondale-sm1000-about-1991-model-to-disk-brakes
Comment: If it's about wet weather stopping distance, you might find a drum brake hub worth looking into for both front and rear. The Sturmey Archer ones I have are very resistant to water intrusion and don't require disc mounts.
Answer: Answer: Its not worth doing, from a financial stand point.
Adding disk brakes to a frame is expensive, risky, and ruins any vintage value the frame had.   The stays are not engineered or designed for the new sideways loading.
Also, you talk about stays, but braking on the rear wheel is nowhere near as good as braking on the front.
If you're dead-keen on fitting disks to this frame, then a better solution is to buy a new front fork with disk mounts, a new front wheel or hub with disk mounts, a front caliper and rotor, new cable/hose, and a new brake lever that suits.   Keep the old fork and parts too, that way you can revert to original spec for no cost.
If you want a disk brake bike for bad weather, buy a second-hand MTB and fit mudguards, leaving your loverly vintage bike for rides.


Transport Melbourne to Byron bay via Gold Coast Airport

Question: I currently stay in Melbourne Australia and I want to get to Byron Bay. So what is a convenient and inexpensive way to get from the Gold Coast Airport to Byron bay? For example: a Shuttle bus service.
Comment: "Best" is a word that can mean many things. Cheapest? Fastest? Most reliable? I might say the best way is in a Ferarri convertible driven by a blonde in a swimsuit (-; But if this is not your idea of best then please add your requirements to the question to make it objective. Be aware that subjective questions do risk being closed.
Comment: @hippietrail I updated my answer with more details...
Comment: I've just done a quick Google search which reveals there are indeed shuttle services from the Gold Coast airport to Byron Bay. But the Gold Coast is a huge area. Would a shuttle from the airport be OK? Otherwise I know at least and probably both of Greyhound and Premier bus/coach companies will also service that route from town centre to town centre. The train station in Byron Bay has been unused for some time.
Comment: If you want to keep the cost down, it might be cheaper to take a bus from Melbourne to Syndey, then a Sydney to Brisbane bus as far as Byron Bay - they all stop off there. With the right ticket, those buses can be pretty cheap
Answer: Firstly you'll want to keep in mind that the "Gold Coast Airport" is not really on the Gold Coast - it's in Coolangatta (or more correctly, half of it is in Coolangatta, half of it is across the state border in Tweed Heads).
There are a few coach services between the Coolangatta/Tweed Heads areas and Byron Bay as a part of longer runs (eg, Brisbane -> Sydney), such as Greyhound. Although there are no trains to Byron, CountryLink does run a bus service from Tweed Heads.  In both cases you'll need to get to wherever the bus picks up yourself - either via Taxi or a local shuttle bus.
There are also private shuttle companies that will go from the airport to Byron Bay, but they are expensive for just one person. eg, Gold Coast Shuttle will charge $75 for up to 2 people, and $20 for each additional person - not a bad price if there's at least 2 or 3 of you, but far more expensive than the other options if you're alone.
Your other option is to fly into Ballina and get a shuttle bus to Byron. eg, Xcede charge ~$15 each way from the "Ballina-Byron" airport (which is in Ballina!) to Byron Bay.


If I send request with PUT, and server return valid page with 403 status. This is correct work?

Question: I send PUT. Server returned 301 status to valid http-address(!), but next response 403 status to hhtp-address. If I copy/paste this address all works correct. Please, say me: this is correct response from server or no?
Comment: It is not really clear what you are doing and moreover what is expected - which means one cannot say if this is correct. But a PUT resulting in a 301 will likely be followed by a GET to the new location given in the response and not another PUT, so this could explain the different responses. Still, I think that with the current content this is not a question about information security, i.e. off-topic here.
Comment: No! PUT -> again PUT -> http-page with 403 status. I think this is not correct response, yes?
Comment: Nothing in the question indicates what the correct response should be. 403 is a perfectly valid HTTP response. Again, it is unclear what really is done and what  is expected (and why) and it is also off-topic.
Answer: From HTTP/1.1 standards, 301 response from a PUT request means the origin server wants the request to be made to the redirected URI. It's perfectly valid.
403 response means you don't have access to the URI. I think you did something wrong while sending the request.


$L^2$-convergence of a series of translates $\sum_{n=-\infty}^\infty a_n f(\cdot - n)$

Question: Suppose that $f \in L^2(\mathbb R)$ is an arbitrary square integrable function and $(a_n)_{n \in \mathbb Z}$ is a sequence which is square summable, i.e. $(a_n)_{n \in \mathbb Z} \in \ell^2(\mathbb Z)$. Does the series of translates of $f$,
$$
\sum_{n=-\infty}^\infty a_n f(\cdot - n)
$$
always converges in $L^2(\mathbb R)$ to a square integrable function? If yes, does it converge unconditionally? If no, can we make additional properties on the sequence $(a_n)_n$ so that the series converges? References to papers are very welcome
Comment: Go to the Fourier side and you'll see everything that there is to see about this question there.
Comment: Thank you for the comment. Am I right to assume that the answer to the above question (regarding the convergence assuming that the sequence is square summable) is "yes"?
Answer: Let $\xi_n=\pm 1$ be arbitrary signs. You want to show that $$\forall\epsilon>0\hspace{3mm}\exists N\in\mathbb{N}\hspace{3mm}\forall m\geq n\geq N\hspace{3mm}\|\sum_{n\leq|k|\leq m}\xi_ka_kf(\cdot-k)\|_{L^2}<\epsilon. $$
By Parseval theorem, $$\|\sum_{n\leq|k|\leq m}\xi_na_nf(\cdot-n)\|_{L^2}^2 = \|\widehat{f}(\cdot)\sum_{n\leq|k|\leq m}\xi_ka_ke^{2\pi ik\cdot}\|_{L^2}^2 $$
At this point, you may consider cases. For example, if the function $F\in L^1([0,1])$ defined by $F(\gamma):=\sum_{n\in\mathbb{Z}}|\widehat{f}(\gamma-n)|^2$ is bounded, then the RHS of the above $(=)$ is equal to $$\int_0^1 F(\gamma)\left|\sum_{n\leq|k|\leq m}\xi_na_ne^{2\pi ik\gamma}\right|^2 d\gamma \leq \|F\|_{L^{\infty}([0,1])}\hspace{2mm} \sum_{n\leq|k|\leq m}|\xi_ka_k|^2.$$ Thus, the series of translates converges unconditionally. Generally, if the Fourier series $$\sum_{k\in\mathbb{Z}}\xi_ka_ke^{2\pi ik\cdot}$$ converges in the weighted $L^2$ space with the norm $$\|g\|=\left(\int_0^1 |g(x)|^2F(x)\ dx\right)^{1/2}$$ for all possible choice of signs $\xi_k=\pm1$, then the series of translates converges unconditionally.
On the contrary, let $f\in L^2$ such that $$\int_0^1 |\widehat{f}|^4 = \infty.$$ Expand the Fourier series of the restriction of $\widehat{f}$ to the interval $[0,1]$, and let $(a_n)$ be its Fourier coefficients. Then,  the series of translates diverges for these choices of $(a_n)$ and $f$.


How hot should wires get?

Question: I am using 10 AWG wire to power a BLDC motor, and these wires can get quite hot. When an IC is intended for high power uses, it is common practice to put a heat sink on it, but what about for wires? Should I simply use a thicker gauge wire?
Comment: The question in the title is different from the question in the question.
Comment: HINT: The insulation of a wire depends on whether it burns or just gets hot. Cheap PVC insulation melts and burns at a low temperature. THHN wire tolerates more heat per given wire gauge. With Teflon insulation you might be able to double the amp rating of the wire, but a lot of other factors come into play.
Comment: Any heat in the cable is wasted energy...
Comment: Are the wires getting hot along their entire length or just at the connectors?
Answer:
How hot should wires get?

How how wires should get depends on application, but there are benefits to keeping just about any device other than a heater cool.  The question ends up being more "How much weight and expense is it worth adding to decrease wasted power?" in the end.

I am using 10 AWG wire to power a BLDC motor, and these wires can get quite hot.

If wires are getting "quite hot" you're wasting a significant amount of electricity.  Specifically, wires get hot because of \$I^2R\$ losses, which is to say the power the wire uses to produce heat, \$P\$, is equal to current squared(\$I^2\$) times resistance (\$R\$).  If you can measure or calculate current, you can choose a wire size with appropriately low losses.  You can also measure the existing wire and calculate its resistance if you don't have a meter.  As a general rule, going down 3 AWG sizes doubles wire size and halves resistance.   AWG sizes step mostly in increments of 2, but that's beside the point.  The calculation of resistance based on cross sectional area measured or from a chart is easy as well.  In AC systems, inductive loads, such as motors produce current out of phase with the voltage (reactive current) and in some cases (probably not yours) it is worth using power factor correction to reduce reactive current on transmission lines.

When an IC is intended for high power uses, it is common practice to put a heat sink on it, but what about for wires?

In almost every case short of superconductors it is more practical to use a larger wire and waste less energy as heat than add weight in the form of a cooling system.  When space is an object, though, such as in a motor or electromagnet, microprocessor, it becomes more likely that a cooling system might be used, even if what's producing the heat are conductors.

Should I simply use a thicker gauge wire?

Yeppers.  If you calculate the current, take into account if they are in free air or a closed space and look at the appropriate DC wire ampacity chart, you can round the current up to the nearest size, apply a derating factor if necessary (a multiplier to decrease the acceptable current for a wire based on factors like ambient temperature) and choose the recommended size of wire for your current.  If you have a substantial length of wire you may wish to take voltage drop into account as well.
If you don't have means to measure or calculate the current, you can at the very least massively improve your setup by embiggening or doubling up the wire until it no longer becomes warm.
Comment: Multiple wires is also a plausible solution, is it not? This might be preferred in certain cases where space/layout is a consideration.
Comment: "embiggening" nice word. And good advice.  I wish you would have say wires should not get hot,  Period.
Comment: @Misunderstood yeah, almost everything gets turned into a word these days =).  Heating elements are wires that should get hot, as are...  Hmmm is there no wire other than a heating element that should get hot come to think of it?
Answer: If you are worried about the cables overheating, check the manufacturer's data sheet.  PVC insulated cables are usually good for 70°C.  Other plastics can handle 90°C.  Specialist mineral insulated cables will go higher still.
But if you are running cables very hot, also check the temperature ratings of whatever they are terminated at (the switch, terminal block or whatever).
Answer:
How hot should wires get?

Wires should never get hot. Not even a little warm.
No more than a few degrees over ambient.

Should I simply use a thicker gauge wire?

Thicker and or add more wires.

it is common practice to put a heat sink on it, but what about for
  wires?

No.  Use more and or thicker wire.

Here's the thing.  If a wire is getting warm during normal operation there is no safety margin for when things go wrong and more current is drawn. Be cool.
Answer: you need to know how much current is flowing in your system, then choose the right wire size.
There are tables like this one to pick the right AWG size.
Due to the \$I^2 R\$ a thicker wire will have less power loss.
Answer: There are two limitations to the conductor size. One is the voltage drop, and often it is the limiting factor, but that's outside the scope of your question.
The second is the temperature rise, more specifically the temperature rise at the highest ambient temperature which translates into the maximum conductor temperature.
The temperature rise is affected by many factors besides the wire resistance (which increases at high temperatures a bit so things get slightly worse) and RMS current. The bundling with other conductors, the altitude, the air flow, even the length of the wire for short fat wires. The upper limit is set by the insulation rating or the maximum temperature the designer will permit, if less.
So in aircraft where weight is important we might use a PTFE/Kapton insulated wire that is rated for 200°C and it can actually be allowed to get that hot worst case. Cheap wire is more normally 90°C or thereabouts. So the ampacity of a given gauge of wire can vary wildly. Here is a marine chart from this web page showing allowable amperage varying over a 3:1 range (unbundled, and without correction for altitude, both which can reduce the ampacity).

Guidance can be found in charts like the above that assume some standard operating conditions and have some safety factor incorporated, but using nomographs and working it out completely is sometimes required.

How hot should wires get?


Prime number size and RSA decryption

Question: Is there a former proof for why larger prime numbers make RSA securer? Maybe a theorem to show that it takes much more time to find out the private key if primes are larger?
Answer: The idea that RSA relies on the difficulty of integer factorization is called the RSA problem. The efficiency of the different methods to perform integer factorization is discussed in a similar article on Wikipedia.
Theoretically, there may be more efficient methods to perform factorization; we cannot prove that there aren't.  Therefore we cannot prove RSA is secure either.
Answer: Increasing the prime numbers does not necessarily lead to an increase in security of the RSA. As an example, when the private exponent is less than $\frac{N^{\frac{1}{4}}}{3}$, Wiener's attack is able to factor $N$ in the polynomial time.
There are other attacks against this system, which can be found in "Twenty Years of Attacks on the RSA Cryptosystem" and "Thirty Years of Attacks on the RSA Cryptosystem".

Prime number size and RSA decryption


Which Wifi encryption method is secure?

Question: Apple just removed the ethernet port from new MacBooks which means we have to use Wifi! But I think WEP encryption is broken, and WPA encryption which I can't see on Mac is also broken. So Wifi means no security, right?
Comment: Welcome to the world of being an Apple customer. Please place your wallet in the receptacle provided and bend over the examiner's table.
Comment: You don't have to use wifi, you can buy a Thunderbolt to Ethernet adaptor.
Comment: @Mike Scott dude i don't wanna pay for a new hardware to use internet which i already have (i'm a poor guy :D ). this macbook i got is a gift. i have no money to buy such things in my life
Comment: If you come across WPS for your WiFi, deactivate it, as it allows attacks on the authentication to the network.
Answer: WPA2 is the only secure method. WEP and WPA are "broken". Also, WEP is easier to crack than WPA. However, any security, even WEP, is better than no security as it will effectively prevent opportunistic connections to your network.
I just checked and indeed the new Mac Books Pro don't have an Ethernet port. All I can say is WTF?!?
Comment: WPA2 is very much different from WEP/WPA and is not broken. Also, regardless of the security used on WLAN you can establish a secure VPN tunnel over WLAN and access the Internet that way.
Comment: yes WTF ! i think even WPA2 can broke same as WPA1 broken ! WIFI is really not a good idea, i don't wanna buy any new hardware to use internet and i can't use internet with my macbook securely, god dammit
Comment: mac OS (snow leopard) don't even have WPA1 ... and VPN cost money and slow also down internet to watch youtube ...
Comment: How can you have Snow leopard and the latest MacBook Pro? They come with Mountain lion. And both should support WEP/WPA/WPA2 out of the box. See if it works with a WLAN access point/router instead of a Windows laptop.
Comment: some of my softwares don't work on lion so i installed snow leopard ...  WLAN access point/routher is a free software or a paid hardware ? what's problem with windows laptop as hotspot ?
Comment: also WPA2 i don't think so be secure : https://encrypted.google.com/search?q=WPA2+break
Comment: It's WPA, not WPA1. And WPA2 is more secure (generally) because it uses the CCMP encryption method, based on AES. WPA on the other hand uses TKIP, which is far weaker, being based on RC4. WEP also uses RC4, but in an extremely bad way that enables very rapid key recovery.
Answer: wpa2 is still the best choice currently.
watch out for wps brute force attempts against a pin, make sure you have a router that you can turn wps off.
http://code.google.com/p/reaver-wps/
Comment: @pier Wifi protected setup  http://arstechnica.com/business/2012/01/hands-on-hacking-wifi-protected-setup-with-reaver/
Comment: Nothing is secure if you use a weak password. Only weak passwords can be cracked.
Comment: what is wps ? only WPA2 exist which looks not secure because of handshake ... (http://www.cloudcentrics.com/?p=2059)
Comment: a strong password, over an open wifi connection while not ussing SSL doesnt do anyone any good. Nor does using a strong password on a website that stores the password in an unencrypted database or text file that is chmodded to 755
Answer: Use WPA2 and turn off WPS if ur router supports it since this is a major security flaw.
WPS: http://en.wikipedia.org/wiki/Wi-Fi_Protected_Setup
Answer: 802.11 until "802.11ad" uses unencrypted management packets no matter what encryption type you use, and will be vulnerable to DOS from a wristwatch that could throw De-authentication packets.  Even enterprise grade RADIUS implementations have recently been proven to be vulnerable within 24 hours or less. Now, when your dealing with autonomous quadrotors, swiping your handshake, and using a distributed computing cluster to crack your personal/WPA2 using multi-instance Dictionary-Supplemented-bogosort-bruteforce, MAC spoofing your client, even a 63-Character(64 HEX) CCMP  VLAN won't help you.
Now with cognitive Radio, it opens a new level of spoofy goodness. Now an attacker will have to implement a "brutespoof" of their MAC spoofing algorithm(similar to aireplay-ng) to attempt to resolve the victims MAC CR algorithm.
Perhaps a ghetto CR MAC implementation could be thrown together using Cron Jobs on a DDWRT/Openwrt router so that both the client, and the router are constantly spoofing their MAC at a mathematically synchronous rate. Unfortunately it then becomes a matter of hardware speed & luck.
Comment: Doesn't really answer the question, but interesting nonetheless.

Which Wifi encryption method is secure?


WebGrid data displayed inside first column

Question: In my ASP.NET MVC application, I have a partial view which renders a table.
My problem, in short, is that all the values of all the properties of each object in the WebGrid's data source are displayed inside the first column of the table, instead of a property value per column.  I can see the per-property cell borders within each first column cell which hosts them.
The partial view's model is List<ReportTableEntry> where ReportTableEntry is:
public class ReportTableEntry
{
    public DateTime Time             { get; set; }
    public int      OpenedSessions   { get; set; }
    public int      ClosedSessions   { get; set; }
    public int      SnapshotSessions { get; set; }
    public int      TotalSessions    { get; set; }
}

The view which renders the partial view calls
@Html.Partial("Table", Model.TableEntries)

(here Model refers to the parent view's model rather than the partial view's model), where Model.TableEntries is a List, and within the partial view, the contents of Model seems to be valid when I inspect it.
I've tried every combination I can think of:

I used the parent view's model directly and created the WebGrid with source: Model.TableEntries.
I tried to use a non-typed model in the partial view.
I specified the grid's column names, and used default values.
I tried decorating ReportTableEntry's properties with ColumnAttribute.
I used grid.Html with and without styles, with and without the columns parameters
I toggled paging, sorting and added/removed the ajaxUpdateContainerId

Nevertheless, all the ReportTableEntry's property values are crammed inside the first table column.
One thing I noticed is that grid.Columns() returns an empty array.
For the sake of completeness, here's the simplest variation which produces these poor results:
@model List<ReportTableEntry>

@{
    if (Model == null)
    {

No data to show

    }
    else
    {
        var grid = new WebGrid(source:                Model,
                               columnNames:           null,
                               defaultSort:           "",
                               rowsPerPage:           100,
                               canPage:               true,
                               canSort:               false,
                               ajaxUpdateContainerId: "reportDataDiv");

        @grid.GetHtml()
    }
}

What am I missing here?
Answer: How dumb...  site.css, td element, float: left - and that's what happens.


Free world flags 4:3 dimensions

Question: Similar to this request, I need some flag images (not icons) with uniform dimensions (preferably 4:3). All the flag libraries I've found all have non-uniform dimensions. Does anyone know of a free resource that caters for my need?
Comment: Most flags have different dimensions by official specifications, and one isn't even rectangular. You could either crop or stretch them to fit your needs. In some cases though (in Brazil), it's even illegal to change the proportions of the flag.
Comment: That being said, the UN and Olymics seem to fly all flags (except for Nepal) in the same aspect ratio.
Answer: I found a suitable library. Flags in both 4:3 and 1:1. I hope this helps others. https://github.com/lipis/flag-icon-css
Answer: Here is what I have found from my research
Famfamfam
We have been using famfamfam flags which are fixed 16x11 icons but this icon set is rather outdated now.
Emoji flags
With the adoption of unicode emoji flags we now have the opportunity to use fixed ratio icons at small pixel sizes. They fit and scale nicely alongside text.
The only caveat is that the flag is based on whatever font is installed so would have a different style other operating systems. For example on Windows emoji flag support seems to only just be catching up now but may require polyfill to avoid only showing letters.
Flags from fonts
If you want a uniform flag image we can still directly utilise the flag files from open-source emoji fonts. If using country codes as lookup these filenames will need renamed back from unicode code points (code example). Granted this is a bit more work but they are an actively maintained source of flags.
Noto Color Emoji
Noto Color Emoji has nice 5:3 ratio waved flags in SVG that can scaled to any size. These images are sourced from Wikimedia then simplified with picosvg and warp added.
Twemoji Color Font
Twemoji Color Font again has fixed ratio flags as SVG. Flag files  names start at 1f1e6-1f1e8.svg.
Examples
Here is the Andorra flag for comparison for the above options.

 Famfamfam
 Emoji Flag
 Noto Color Emoji (16px png)
 Twemoji

Free world flags 4:3 dimensions


What kinds of scripts go to which of `/etc/pm/sleep.d` and `/usr/lib/pm-utils/sleep.d`?

Question: In Ubuntu 16.04, the scripts under /etc/pm/sleep.d and /usr/lib/pm-utils/sleep.d are run upon suspension/hibernation and resuming/thawing. If I create a script, can I place it under either directory? Is there some convention of what kinds of scripts goes to which directory? Thanks.
Answer: The "usual" conventions apply: anything under /usr, outside of /usr/local, belongs to the packages provided by the distribution; anything under /etc belongs to the system administrator (although packages can place defaults there too).
Thus in your case, your files should go into /etc/pm/sleep.d.
Quoting the Filesystem Hierarchy Standard (which Debian follows, as do Ubuntu and most other Linux distributions):

/usr is the second major section of the filesystem. /usr is shareable, read-only data. That means that /usr should be shareable between various FHS-compliant hosts and must not be written to. Any information that is host-specific or varies with time is stored elsewhere.
Comment: If you put something in `/usr` and it's in a distribution-supplied directory, expect that it may get clobbered on your next update! :-) (That's not really true: distributions are really careful about not touching stuff that's been altered, but it's good practice to keep your site modifications separated from the distribution. If you ever need to recover or upgrade/change your distribution, you'll be glad you did!)


Local Drupal 7 user in database

Question: I want to save a user's email and username when a button is clicked.
I assume I have to do this via PHP but I can find the user column at localhost/phpmyadmin. Where is the users' information being stored and which is the MySQL query to achieve that?
Answer: You should not use a direct MySQL query to update anything.
In this case you can use user_save(); which it is basically, load the user object -> change data -> pass it to user_save(); or even better user entityAPI and entity_metadata_wrappers
The default table where drupal saves user data is users, there you can find the email and username

Local Drupal 7 user in database


Why is my internal memory almost full while the files add up to only a few gigabytes?

Question: My HTC One M8 internal memory is almost full (15.40 out of 16). The phone says it's mostly applications. But when I connect it to my computer, go to Internal Storage and add the sizes of all directories, the total is about 3 gigabytes.
Comment: What you see from your computer is just a little part of the storage you have access to. It doesn't include the space where apps are installed, where their data reside, where their cache is, where the system settings are stored, where the system logs are written to, and so on. It's like you see the showroom of a shop, it doesn't tell you how much there's in stock in the rooms behind it belonging to that shop.
Comment: Check your settings, storage menu.
Comment: Yes that's where I checked it. It says my applications are using 13GB. But I just downloaded DiskUsage and it seems that I have ~4GB applications and roughly 8GB system files (OS). Does that make sense? Does the OS use so much space?
Comment: Depending how bloated the OS is, it may occupy from barely 4 to 10GB or more.
Comment: The confusing part is, when I go to Storage in Settings, it says Google Music is taking 8GB. However DiskUsage says Google Music is using 200MB (which makes sense, because the downloaded music is actually on external storage). So I don't know if I will actually get 8GB of free space if I deleted Google Music (which I'd rather not try for obvious reasons)
Answer: Devices have different partitions for different purposes. Data storage is bigger because you will need to store your pictures etc. BUT the partition that your device uses for apps is always limited. You might want to move some apps to sd if you are able to.
For example here is the partition table to a Samsung Galaxy S5:
<code>aboot -> /dev/block/mmcblk0p6
apnhlos -> /dev/block/mmcblk0p1
backup -> /dev/block/mmcblk0p18
boot -> /dev/block/mmcblk0p15
cache -> /dev/block/mmcblk0p24
carrier -> /dev/block/mmcblk0p25
dbi -> /dev/block/mmcblk0p4
ddr -> /dev/block/mmcblk0p5
efs -> /dev/block/mmcblk0p12
fota -> /dev/block/mmcblk0p17
fsc -> /dev/block/mmcblk0p19
fsg -> /dev/block/mmcblk0p9
modem -> /dev/block/mmcblk0p2
modemst1 -> /dev/block/mmcblk0p13
modemst2 -> /dev/block/mmcblk0p14
pad -> /dev/block/mmcblk0p10
param -> /dev/block/mmcblk0p11
persdata -> /dev/block/mmcblk0p22
persist -> /dev/block/mmcblk0p21
recovery -> /dev/block/mmcblk0p16
rpm -> /dev/block/mmcblk0p7
sbl1 -> /dev/block/mmcblk0p3
ssd -> /dev/block/mmcblk0p20
system -> /dev/block/mmcblk0p23
tz -> /dev/block/mmcblk0p8
userdata -> /dev/block/mmcblk0p26
</code>
Hope this helps.
Comment: I think mentioning the list of partitions doesn't help solving or even explaining the problem. One thing that you can add in your answer is to show what kind of things are consuming internal storage which OP cannot see from PC using MTP. A screenshot of a disk analyzer type app in work in your phone could help OP proceed and understand their own problem and fix it. :-)
Answer: In most Android phones, the application data is also saved in a hidden data directory which is part of internal storage.
You can free up that space by clearing app cache and data and removing useless apps.
You can go to settings > applications > app_name and see how much data it has stored.
Warning: clearing app data will make the app behave as if it's just freshly installed and never used.
You can also clear your social media apps directory like whatsapp and Facebook folder to make more space


Clear and distinct

Question: Descartes talks about clear and distinct perceptions, in which clear means 'what is present and accessible to the attentive mind' and distinct means 'being clear and sharply separated from all other perceptions so that it contains within itself only what is clear'.
The clear part I can understand, but I have difficulties with really getting the distinct part. In the Principles of Philosophy, Descartes does mention an example about pain that shows that a perception can be clear without being distinct, but this doesn't really help me either.
Comment: See [Meditations, II, 11-on](http://www.wright.edu/~charles.taylor/descartes/meditation2.html) for the "wax" mental experiment, with multiple occurrences of "clear and distinct" as opposed to "imperfect and confused".
Comment: What is a dog?
If we were to answer "an animal" then that would be clear because it includes every dog but not distinct as also includes bears, eagles and tiny lizards.
Tell me if I'm wrong please.
Comment: https://plato.stanford.edu/entries/descartes-ideas/#SimNats
Answer: I assume the (implicit) question being asked here is what "distinct" means in this context, in a more accessible fashion than the quote presented in the question.
Note that from the definitions quoted, the set of perceptions that are distinct is a strict subset of the set of perceptions that are clear.
Hence, a distinct perception must be clear, in addition to one's having the ability to distinguish between different distinct perceptions.
As for the second part of the definition of "distinct", this introduces the requirement that when one removes all other perceptions from consideration, the one perception that remains must still be clear, and must not contain anything else which is not clear.
Answer: Suppose each element of Set A and Set B is clear or definable and does not have any common element they are distinct.  Since ∅ is a common subset of A and B, in this case, while defining the term 'distinction' we can't use the term common subset.
Strictly speaking, since set of natural numbers includes in the set of rational numbers, we can't say set of integers is distinct from set of rational numbers.
I believe this might be the implication.

Clear and distinct


Are cache contents specific to a process?

Question: Suppose the L1 cache is filled up with data from some process. Now CPU loads another process. Does the new process share cache contents? Or the cache has to be invalidated completely in each context switch?
Answer: It depends, there are several kinds of caches.
Some caches, known as PIPT (physically indexed, physically tagged) operate entirely on the physical address. The cache subsystem is independent of virtual memory, so it doesn't matter which process is accessing the cache: all processes share all cache entries.
Some caches, known as VIVT (virtually indexed, virtually tagged) operate entirely on the virtual address. In this system, a cache entry is only valid for a given process. There are several ways to ensure that a cache entry will not be used in the wrong process:

The operating system may flush the cache at each context switch. This requires no hardware support but is obviously inefficient unless context switches are rare.
The operating system may assign disjoint sets of addresses to distinct processes. This again requires no hardware support, but is a heavy burden on the operating system (it means that the MMU is effectively as a mere MPU (memory protection unit)).
The MMU and cache may contain an extra label which is set by the operating system to an identifier for the process that owns each page or cache entry. ARM and Intel call this label ASID (address space ID). Each cache entry is only valid for a virtual address with the matching label.
There are also VIPT caches (virtually indexed, physically tagged). The physical tagging ensures that the cache entry will only be served to a request for the correct chunk of memory. The virtual index means that if a page is shared at different addresses in different processes, the cache entries will not be shared.

See the "Address translation" section in the Wikipedia article for more information on these kinds of caches.
Cache types typically vary between processor families within the same processor architecture. Even on a given processor, data and instructions caches may have different types, as can L1 vs L2 (and more) caches.
Comment: +1 For flushing "no hardware support" may be a *slight* exaggeration. Unless the OS "flushes" the cache by loading shared—at the same virtual address—or inaccessible content, the hardware would have to support some kind of flush instruction. (Even this kind of "flushing" would require OS knowledge of size, indexing function, associativity, and replacement policy.) A flush instruction for a specific address or page may be useful for other reasons (though still may not be *necessary* for a working system), but flush index or flush cache is less broadly useful.
Comment: If hardware recognizes context switches (e.g., a write to a special register with the page table base), it can transparently implement ASIDs. A 1-bit hardware-managed ASID would allow gradual flushing of the cache in the common case of a context fully using the cache. Other than having content that is shared across contexts generating false misses (and delay in continued flushing if a new context does not fully use the cache), this can be indistinguishable from PIPT. (With OS-based ASIDs flushing is needed for ASID reuse.) Write-through and instruction caches can be invalidated in 1 cycle.
Comment: I realize these comments are beyond the level of the original question and are a bit chatty, but I wanted to share the thoughts.


How to get inner content of Content editor web part Programatically using Client side Object model

Question: I am unable to get Inner content(rich text value) of Content Editor web part, Please Provide some code sample on how to do this
Comment: What have you tried so far yourself? The better you specify your question, the easier and more likely you'll get the answer you need.
Answer: Refer below code example:
<code>$("textarea[Title='System Description']").closest("span").find("iframe[Title='Rich Text Editor']").blur(function(){
  alert($(this).contents().find("body").html());
});
</code>
In which the System Description is the rich text editor.
For more details here is the great sample explained by Marc: Finding the Contents of a SharePoint Rich Text Column with jQuery
Also one thread was answered on Stackoverflow here: Retrieving rich text box sharepoint in javascript


Are gate ramps sloped?

Question: If you've ever seen an airliner park at its gate, you'll likely note that sometimes it will move beyond slightly beyond its designated parking line. However, you may see that after the brakes are applied the aircraft moves back in "reverse" onto the correct parking line. It appears to me that this is as a result of gate ramps being at an angle. Is this correct? If not what are other possibilities for this phenomenon?
Comment: I've never seen (or felt) an aircraft move in reverse after coming up to the gate (and I fly a lot). I'm assuming that you are asking if the concrete part the aircraft parks on is at an angle? Then no, it is not (typically).
Comment: What you may think is missing the "mark" is possibly not for that model aircraft. There are usually 4 or five marks - but not for all aircraft. The marks are often annotated with certain aircraft like "737" and when a 757 is parked, the ground crew knows they need the nose 4ft ahead of that mark. A perfectly flat surface is undesirable for moisture, de-icing runoff, and fuel spills.
Answer: (Source) Drain system.
ICAO SARPs Annex 14 does not mention a direction of slope, it only says:

Recommendation.— On an aircraft stand the maximum slope should not exceed 1 per cent.

So that's fairly level. But tiny slopes are needed, but not necessarily facing away from the terminal. They are needed to guide the rain (and any fuel) toward the trench drain system.
Not always are the drains parallel to the terminal and behind the parked aircraft. They can be parallel to the plane's longitudinal axis or even at the terminal.
I have never seen a parking that intentionally overshoots the mark. What you may have seen is a small backward jerk, like when trains stop. That's due to the offloading of the nose landing gear.
Pilots are guided in via stand guidance systems or ground marshallers. And they stop when the stop sign is shown. Guidance systems are never calibrated to overshoot the spot (the pilot might end up having to blame the birds).
Answer: At most airports, the slope is away from the building for water drainage mostly.
This results in a slight rearwards movement when the pilot releases the park brake and the wheels roll back and compress slightly when they rest against the chocks.
This is a pain when it comes time to pushback as the airplane needs to be towed forwards a bit to enable the rear chocks to be removed.

Are gate ramps sloped?


Image target display in unity Vuforia

Question: I am using unity 4.5.1f3 and using the Vuforia sdk 5.0.5.I have downloaded the sample project from the Vuforia site.When I tried to run the sample of Imagetarget project,it asked to add license key.Then I added licensed key to the app.Then when I runned the project again its showing me and error
<code>MissingMethodException: Method not found:   'UnityEngine.Behaviour.get_isActiveAndEnabled'.
Vuforia.VuforiaAbstractBehaviour.UpdateStatePrivate (Boolean forceUpdate, Boolean reapplyOldState)
Vuforia.VuforiaAbstractBehaviour.Update ()
</code>
The Image marker detection can run but the camera video doesn't show in the background.
can anybody help me solving the issue?
Answer: If you are running the x64 bit version of unity on a PC you will need to run the x86 version for your webcam to work correctly in the editor.
You may also have to set some of the plugin files to run x86 also for your project to run correctly.

Image target display in unity Vuforia


White line in footer of EE Admin CP

Question: For a while, I seen a white line appear in the footer of my admin (see the screenshot). Can anyone tell me the best way to debug it?
Answer: Use a browser inspector and examine the generated source. Chrome's web inspector is ideal for this, just right click the line and select Inspect Element. This may give you a clue as to what is creating it.

White line in footer of EE Admin CP


How can I fix computer that won't even boot up

Question: I just had to update my drivers and clean my disk due to high disk usage, I went to reset and now my screen just stays plane black, it'll change to a white screen for a split second every once in awhile, but won't actually let me on. Please help
Comment: Can you boot some other OS, like a Linux distro on a LiveCD ?  If so, and you have enough external storage you can backup your stuff and reinstall...  Also try booting in safe mode - if you have a really big disk, it could be running a forced disk check... which could take a LONG time
Comment: @ivanivan I don't even have another OS, I think I might just have to completely reinstall
Comment: @ivanivan also forgot to mention I can't even boot into safe mode
Comment: Have you tried booting into Last Known Good Configuration?  I'm presuming you are only having issues when Windows 10 is booting and that it passes the POST.
Comment: @Enigman won't even go into start up, I think the disk might have died on me, and I need a new hard drive, but I'm not sure.
Comment: @Enigman thank you for your answers I don't know what I did but I got it working by spamming enter and just kept retrying a graphics drive restart. I'm not sure how to process though in all honesty
Answer: Some of the first things I do when I have issues:

Unplug the power cable from the computer and press the power button to drain the capacitors off all power. Then plug the power cable back in and try to boot.
If you're using a laptop, then remove the battery and the power cable and hold the power button till lights go out, which should be almost instantaneously.
Try and connect the video cable to a different video port on the computer, and if you have a graphics card, try to use a port that is coming from the motherboard instead of the graphics card.
Try a spare monitor, or a TV if you can
If at all possible, boot from a USB or CD that has Linux on it, such as Ubuntu or Mint. This will test things such as the monitor, the computer hardware, and other components that will narrow down the problem.

Moving on:

What Operating System are you using?
Are you using a laptop or a tower computer?
Do you have a graphics card installed and what model is it if so?
What drivers do you try to update and what process did you go about updating them? Like Windows Update or some third party tool?

Before you do any wiping and reinstalling, as long as there is no foul play like malware or hard drive failure, your data should be able to be recovered. It's as simple as taking the hard drive out, connecting it to another computer by a SATA to USB adapter, and copying the files to a new location then wiping the disk and reinstalling and copying the files back over to the freshly installed OS.
Sorry for the all the questions, but it will help to narrow down the problem. Thanks
Comment: Thanks man, I ended up getting it figured out, not sure what the problem was, but it did end up resolved after much spamming. Right now I'm just updating windows just in case that was an issue which it most likely was. Very helpful though, I run through the same process you do.
Comment: Sounds good! Good luck Tallon!
Comment: Thanks, by the way this community is so much nicer than the chemistry community in all honesty

How can I fix computer that won’t even boot up


Are there any freely available plugins or integrations for JIRA to write test cases?

Question: Are there any freely available plugins or integrations for JIRA to write test cases?
Comment: What have you tried? Have you searched for any plugins or integrations already? Why didn't they work for you?
Answer: There are several paid options, such as Zephyr, Xray, and Test Management for JIRA. We use Zephyr at my company. All of these plugins have free trials available, but I'm not aware of any that are free.
I'd recommend browsing the Atlassian Marketplace and filtering by "test" and "free" to see if any of the plugins fit what you need:
https://marketplace.atlassian.com/search?moreFilters=free&query=test
Just be aware that some of the "free" plugins require an outside subscription to use.
Answer: I've seen integration of TestLink with Jira. There is even a post how to combine those two.
But I would really recommend paying for something like Zephyr or XRay. This thing above is madness.


Dealing with a rejection from a journal

Question: I am a post-doc in economics. I know that rejections are quite usual but I feel very sad (I think more than necessary) because of rejections.
For a paper on which I worked for four years, I got two rejections since last year.
I already have two accepted papers but I am overwhelmed with a rejection that I received this morning and I am wondering whether academia is really a good choice to me. I know this is an unnecessary feeling. What to do in order to deal with these situations?
Comment: Let your emotion simmer for a while.  Time heals, and it is important to realize life is much more about a rejection.    Do other things and forget about the paper for the time being.  Once you are ready, pick yourself up and continue onward.  After being in academia for so long, it still hurts but I know it will pass.  Nowadays, I can hardly remember any of the emotions I felt when my papers got rejected; sadly, same with acceptance :|
Comment: Have you discussed it with your PI?
Comment: The fact that you feel something means you care enough about the work.  Imagine one day you could care less about whether a paper is accepted or rejected.  At that time, I think it's time to leave research and change course.
Comment: I'm pretty sure this has been asked before, but I can't find the question.
Comment: @henning I did not find either. This is why I asked the question...
Comment: @optimal control not what I thought I remembered, but related and perhaps helpful: https://academia.stackexchange.com/questions/73180/how-to-appeal-against-an-unfair-decision-conference-paper/73185?r=SearchResults#73185
Answer: I read recently in economics a single publication in a distinct top-tier journal earns you professorship. Hard to understand for me as a physicist, but if it is really like this and I know the ratio PhD students/professors in economics is much much smaller than in experimental sciences (at least in Germany), then you have to live with the fact that the acception/rejection is more difficult/sophisticated and more lottery-like than in other scientific branches. On the other hand, your chances to get tenure are likely also much higher than in those. I hope this solaces you a bit :-)
And if you got 2 papers published already, you know there is nothing wrong with the way you write your papers in general.
Answer: Any sort of rejection in life is hard to take.
But note that there are several reasons for a paper being rejected other than the quality of the paper, and, certainly, other than your own ability/worth as a researcher.
Poor fit for the journal, and poor timing come to mind. Some reviewers are just nearly impossible to get anything through, for a variety of reasons.
I'd suggest that you get some additional feedback on your paper as well as some advice on your career before you toss in the towel.
But the pain will still be there for a while. It's just a natural human reaction. Find joy elsewhere for a bit until it subsides.
Answer: Rejection is hard. But rejection happens, even to great writers, in and out of academia. My favorite rejection letter is this one:
"We're sorry, Mr. Kipling, but you don't know how to use the English language."
Did they give any reasons for rejection?
Was it an outright rejection or a "revise and resubmit"?
In addition to the reasons listed by Buffy, I will suggest that you might have aimed too high - perhaps the journal is so high prestige that they reject almost everything and perhaps a less established journal would be better.
I work as a statistical reviewer (not in economics, though) and, while I almost never reject, sometimes my problems with the methods are a reason that the editors reject.
Another thing to note is that you got two acceptance already (congratulations!)
In any case, I think that getting one paper rejected is not a good reason to change careers.  Perhaps there is someone you can talk to about dealing with rejection?
Comment: Do you happen to have a source for that Kipling quote?
Comment: I read it in The Experts Speak: An Encylopedic Compendium of Authoritative Misinformation.
Comment: Do you think the quote is real?
Answer: My first paper got rejected twice. I was feeling very low and doubtful about it. I made up my mind to ask my advisor about my performance and tell him that I had considered leaving my PhD. He told me to stick with the project and that he was happy with the job I did. The next two years I clung on to this. It was still difficult but I didn't leave the project and got my PhD. I however decided afterwards to leave academia because of the lack of appreciation/encouragement and the hard competition for a permanent job in academia.

Dealing with a rejection from a journal


Galaxy S2 Philz Touch 5 Bootloop

Question: My girlfriend's phone is a Galaxy S2. The battery was crap and the phone started bootlooping. We've replaced the battery but it is still happening. I can get into recovery mode, but I don't know anything about Flashing Roms. We're trying to avoid Factory Reseting the phone, in order to save the data. I have tried wiping the various caches. Is there anything I can do? The recovery screen also has a Philz Touch 5 menu, I believe the phone is rooted (although honestly I know nothing about it, I never rooted my phone).
Comment: Philz recovery is a custom recovery, so something has definitely been done with the phone. You could restore to stock (but that will wipe the phone), or try and flash a custom ROM over the existing one (dirty flash) and see if it boots and retains data. For how to flash head to XDA developers for the EXACT device she has (the specific type of S2) and you download a zip of the ROM and in Philz "install zip" and that's about it.
Comment: You might wish to see our [boot-loop tag-wiki](http://android.stackexchange.com/tags/boot-loop/info) for some first-aid. Though most of it you probably already tried, it still might contain something additional (like the safe-mode hints).
Answer: It's definitely rooted..
So it's better to completely wipe the phone..
But as you need your data, you can try and run it in safe mode.
As soon as you boot your phone , press down the volume down button, keep holding until you reach the lock screen. then press the safe mode button on bottom left..
http://www.tested.com/tech/android/3071-how-to-use-androids-safe-mode-to-save-a-phone-from-boot-loops/
In case you are flashing the best rom for Galaxy s2 is the Pound rom(Unsung Hero) or Cyanogenmod(popular)..

Galaxy S2 Philz Touch 5 Bootloop


How do you strain pellet hops out of wort or beer?

Question: After boiling pellets how can I deal with them? Is there a simple way to get them out of the wort, or can I leave them during fermentation? In that case will I be sure they will drop on the bottom and not cause problems?
Answer: Usually the pellets will dissolve during boil and settle down to the bottom of your kettle when you cool your wort. Then, when transferring to the fermentor you can just leave them behind (easier to do with a siphon).
Or
Use a hop bag - put the pellets on the bag, when you are done with the boil simply pull the bag out.
Comment: Will all the crumb stay in the bag?
Comment: In my experience most of it will.
Comment: Yep the hop muck stays in the bag. What doesn't is small and will settle out with the trub.
Answer: I use a bucket for my fermentor so I bought a steel mesh strainer.  I then sanitize the strainer with starsan and place the strainer across the top of the bucket and run the wort through it.  This strains out the hop gunk and helps with aeration by turning the wort into droplets as it falls into the fermentor.
Comment: I do the same but have found that most steel strainers will end up getting pretty clogged halfway through pouring the wort if using pellets. They develop a thin layer of hop sludge over the surface area of the strainer and pouring slows to a crawl quickly. However for about $20 from a kitchen supply store you can find a [china cap strainer](http://www.wasserstrom.com/restaurant-supplies-equipment/Product_141803) which allows for more volume in the strainer so much faster drainage and less clogging. Well worth the investment IMO.
Answer: If you are siphoning your beer out of a flat bottom kettle/pot a whirlpool can be very effective.
After you are done chilling put your brew pot in the location that you plan to siphon from.  Using a clean and sanitized spoon stir that wort up into a good vortex.  Once the whirlpool has started, remove the spoon and replace the lid.
Then go about cleaning up from your session.  Sanitize your fermentor and siphon equipment, prepare your yeast.  If you give the pot 30 minutes at least to settle down much of the break material and pellet hops will get pulled to the center bottom of the pot.
Then you can remove the lid and siphon from the side of the pot without pulling too much of the gunk.  Some won't hurt, but doing it this way will help you get much less of it if you want.
Answer: We filter the trub out through a sanitized fine mesh bag during siphoning. This way we don't worry about about the siphon pulling the trub - it ends up in what we call a trub sack, from which more wort is squeezed out while pulling it out of the fermenter. Make sure not to drop the bag into the fermenter, as trub sack may get heavy during the siphon. Not sure if there are any downsides to this method, we find it easy and seems to do the job.
This is what it looks like:
Comment: Are you using a bucket or a carboy? I could see this being difficult with a carboy due to the skinny neck.
Comment: @roto See edit above. At first we tried using a tight rubber band around the neck, but didn't trust it when the sack got heavier. So what we do now is just hold it with hands when necessary.
Comment: Thanks for the update! I may need to try this. I've been getting a lot of trub in my carboys lately. I haven't noticed any effect on the finished beer, but would still prefer it not to be there.
Answer: You can make a easy pellet strainer bag with cheap parts from a hardware store.  This link offers easy instructions. Instead of one large dowel rod, one can use thread steel rods with washers and nuts in a plus shape to position in on a kettle and not slip.
http://www.instructables.com/id/Home-Brewing-Grain-and-Hops-Strainer/
Answer: I use a sanitized nylon bag, like the boil in bags.  I bought it to replace the bag I use for mashing and filtering through my zapzap.  It was too narrow for my kettle, so I re-purposed it as a hop filter after boiling.  I sanitize by immersing it in boiling/boiled water for about ten minutes.  I use my boiling spoon to help push out the retained liquids.  I use buckets so the slightly smaller boil bag is perfect size.  I like milancurcic's carboy solution, the narrow carboy neck acts as the system to push out the hops.
Answer: Whatever you decide to do I would suggest handling it on the kettle side of things.  If you strain at the fermenter (mesh bag, SS strainer, etc) you'll probably create a lot of unwanted aeration of the wort as it foams up.
Comment: This is only correct if you cool in the fermenter. Most cases I know of are cooling in the kettle. If you are strain into the fermenter when the wort is at or around pitching temperature, the aeration is acutally wanted.


New workplace asking for bank pin and account number

Question: My new workplace with a modeling agency had me sign up for a new bank/ credit union and want my account number and account pin to verify that a payment goes through once they send it, so they can monitor that it goes successfully.
Then they said after that I can change it.
It seems legitimate but I'm not sure what to do.
Thoughts please
Comment: `It seems legitimate` No, it absolutely does not.
Comment: Modeling agency = scam    in most cases
Comment: They need the PIN to do money laundering - https://en.wikipedia.org/wiki/Money_laundering , or to steal from you later.
Comment: Or steal from you now. With the PIN they can get access to the account, overdraw the account, and transfer the money offshore. When you realise, your account is in the negative, and because you gave the PIN away, you are liable to pay the bank to make the account not negative.
Comment: Here's an example of how this scam might work: https://money.stackexchange.com/a/112242
Answer: This is a scam.
I'd do a little research on that bank/credit union, too.  Directing you to a specific bank seems fishy.
To do ACH payments, your employer needs the bank's ROUTING number, and your account number.  No one EVER needs your PIN.  PIN sands for PERSONAL identification number.  Keep it personal.
Comment: They direct you to a specific bank because they know that bank's policies well enough to exploit them. For instance, some banks will allow a "courtesy pay" overdraft up to $200. Some banks will make $100 of newly deposited check available immediately (before the check actually clears). And so on. You should absolutely alert the bank to the scam. The bank's fraud team will be interested in investigating and potentially considering additional countermeasures or policy changes.
Comment: @GregoryCurrie no, it's a scam because they want the PIN. Any legit employer would need account number and routing number, but not the PIN.
Comment: Yes this is a common scam method. Set up a fake account that needs to transfer to an account in your name to get money. I've seen fake jobs set up and sometimes it involves being an accountant or something for a seemingly legit job. I heard of this scam involving signing fake checks and depositing it into your account and having you give the company your account # and pin. Sometimes when you deposit money, they don't make the whole amount available but you can withdraw say $200 bucks for a paycheck until it clears. The check will eventually bounce and you'll have to repay the amount withdrawn.
Comment: If it's not a scam, should they give out their PIN?
Answer: Personally, I would not agree to do so. I do not work in the modeling industry, but this request is definitely not normal in any industry I'm familiar with. I would propose that I verify the payment for them instead of giving them access to a bank account in my name.
Edit: To be completely clear, I would have no problems with giving them the account number.
Comment: Not only is this not normal **IT"S A HUGE SCAM RED FLAG**. Nobody needs your PIN to verify a transaction, and giving it to them violates the terms of your bank account.
Comment: Agreed. Your account number is normal, so they can deposit the money. Your pin is absolutely not.
Answer: Never give your pin to anyone.
Ring the bank and check, they will tell you the same, in fact you can lose any protection the bank offers if they discover you gave the pin out.
For some who don't seem to get it:
Ring any bank you like and ask them if you should, or should not, divulge your PIN... Any bank will tell you no, try Bank of America, JPMorgan Chase, Wells Fargo, Barclays, Lloyds or UBS - any of the well-known banks.
Get the agency to make a payment and you confirm it works later that day or the next.
As others have said, it is a scam.
I was meeting the bank yesterday - advisor had full access to my accounts as they should, but did not ask for my pin...
Also, you can give them the IBAN number which most banks use now and that works for them sending you money. At least the banks in the UK and Switzerland use the IBAN...
Comment: **-1** The first sentence is OK, the rest is **very bad advice**. After it's obvious that it's a scam, the OP should break off **all** contact with them. Don't give them the benefit of doubt, don't try to reason with them or test them or to propose alternate paying methods. They are scammers, end of story. And about "ringing the bank", make sure you search yourself for the actual phone number of the bank, and don't use any information those "employers" gave, because they almost surely control that number and will pretend to be the bank and will state that it's perfectly legit.
Comment: @SolarMike : Duh, because there are other, perfectly good answers already?
Comment: Losing your bank's protection if you give out the PIN is bad enough.  What's even worse is that you may also have to prove to bank investigators and/or law enforcement that you weren't the one that committed the fraud, even though it was done using a secret PIN that supposedly only *you* know...
Comment: @SolarMike : The questions stated to sign up for a new bank, maybe you missed it. And even if you meant your old bank, it's a bad advice to continue testing the scammers ("Get them to make a payment and you confirm it works") because that leaves some trust in the OP that there is still money to be won from them, and that they can be reasoned with and that a payment method can be negotiated which is secure and guarantees money for the victim. Which is exactly the mentality the scammers want the victim to have.
Comment: @Val So with such good advice and points, why have you not posted an answer?... Are you connected with the industry?
Comment: @Val I have had the same bank for 15 years - I think I know the number to ring... perhaps **you** did not understand...
Answer: As everyone else is already saying, this is almost guaranteed to be a scam, but I wanted to highlight that modelling agency scams can go way beyond stealing your money.  Fake modelling agencies can be fronts for human trafficking, and you should be very careful.
While suspicious on its own, they are in general correct that you can simply change the PIN afterwards (though if they asked you to use a specific bank/credit union, they may know a "security question back door" to recover the account with an old PIN).
The more dangerous side of this comes in when you consider that scammers want to be blatantly obvious that they are scamming you, because they want only the most gullible people to self-select by following through.  This suspicious bank activity could be the net they use to filter out easy marks, and then follow up with "this great modelling contract in [another country], you just need to give me your passport so I can buy your plane tickets and [perform dubious action] to get you set up!".
Comment: And in case this isn't obvious either: *Do not give them your passport*.
Answer: I can sit here and try to think about if it's a scam or not. A lot of other answers have suggested it's a scam. But they miss the mark, because at the end of the day, it doesn't actually matter if it's a scam or not.
There are certain things you should never do, regardless of the situation. Giving someone your PIN is one of them. It doesn't matter if it's "legitimate or" not.
They may be able to convince you 100% that it's not a scam. Well done to them. You must NOT give them your PIN.
Let's say you trust everything they are saying, and it all checks out, you get verification from the queen, and everyone in the world says it's not a scam. You must NOT give them your PIN.
Let's say you know, somehow, it isn't a scam. You know absolutely and without a shadow of a doubt. You must NOT give them your PIN.
Don't get tripped up on a game where they have to prove their good intentions. You have to form the mindset that there is no scenario where they are getting your PIN. It's that simple.
Answer:
It seems legitimate but I'm not sure what to do.

It probably isn't. They don't need your PIN number. If they want to make a small deposit they only need your bank account and routing numbers.
I would NOT give them my PIN number.
Answer: 100% agreed that if they transfer money to your account, they'd know that they did through their bank. It's sort of like if you write a check for a bill, you'd know they cashed it because you'll see it on your account. You wouldn't need their account or pin number to do so.
This sounds 100% like a scam. Models are particular targets because they're looking for odd jobs to break into the industry and build a portfolio. So my advice is to simply forget about this job and walk away. If you already shot photographs, keep in mind it's very easy to set up a fake studio at some abandoned building. Verify the agency is real and the person actually works there. Ask for cash but if they insist on you giving them your account number and pin, do not do it.
Edit: Not even the bank would even know your pin number. They'd have no way to get your pin number. That's how secured it is. Your pin number is encrypted and salted at your bank and on your card if you have the little chip in it. So it's very secure, very personal. You should never give it out.
Edit: This is 100% a scam. The scam involves seemingly valid work and they give you a paycheck. You deposit this paycheck that appears to be from a legit company. They ask you provide them an account # and pin to track and you deposit. Most banks make paychecks have some amount available right away until it clears for good standing accounts. Typically $200 or so for a US bank. What these scams do is they withdraw that $200 area (or more if you have money in your account for withdraw) and eventually your check will bounce and you owe the bank that $200 for having withdrawn (since you can't prove you didn't until you make a police report). You'll also be out of whatever over that $200 dollars, possibly never recovering it.
Answer: There's absolutely no reason to give anyone your PIN.  However, even with your PIN, they'd still need your debit card number, expiration date, and CVC.  Then they'd need to encode that onto a card to withdraw money from an ATM. (Your bank account # isn't the same as your debit card #)
Are you sure they're not asking you for your routing number and account number?  They can't do DD w/o knowing the routing number
It's possible this is a scam, but even w/ their bank account # and PIN they wouldn't be able to do anything w/o swiping your debit card as well.
edit: it's also possible they're referring to the telephone customer service PIN (which some banks have as an extra security measure to verify your identity.  these are (to my knowledge/in my experience) totally separate from your ATM / debit PIN).
Comment: You are saying not to give out the PIN, which is good, but you shouldn't qualify that by saying the risk is mitigated factors, because you don't actually know how strong those factors are. Debit card number, and expiration date are not security features and can be considered public knowledge. CVC is not part of ATM authentication at all. So what you're left with is relying on the fact that it's hard to manufacture a card which, depending on the security features, may not be hard at all.
Comment: Also, the OP says account number and account PIN, which suggests to me it's online login credentials.
Comment: "`even w/ their bank account # and PIN they wouldn't be able to do anything w/o swiping your debit card as well`" - with those, they can set up online banking. Then it's "Goodnight, Vienna".


Points of Scholze's Anticanonical Tower

Question: In his paper "On torsion of locally symmetric spaces", Schole introduces a perfectoid space, which is the anticanonical tower. He claims that points coming from $\text{Spa}(C,C^+)$, where $C$ is a complete algebraically closed extension of $\mathbb{Q}_p$ parametrize abelian varieties with a polarization and a trivialization of the Tate module. I really cannot see why this holds true. So, consider such a point. How do I get a unique abelian variety instead of a projective system of abelian varieties? And second, how do I get the splitting?
Answer: Scholze's object is a limit (in some rather delicate sense) of objects at finite level. The $n$-th of these finite-level objects is a moduli space for abelian varieties $A$ with a polarization $\lambda$ and a symplectic basis $B$ of their $p^n$-torsion (satisfying some "anticanonical" condition but never mind that for now).
The key is that the map from the n-th layer to the $(n-1)$-th layer sends $(A, \lambda, B)$ to $(A, \lambda, B \bmod p^{n-1})$. The abelian variety doesn't change: you just throw away some information about the level structure.
I'm assuming that Scholze's "tilde-limits" are well-behaved enough that a $C$-point of the limit is the same thing as a compatible collection of $C$-points of the spaces at each finite level. So a $C$-point of the infinite-level object consists of a single polarized abelian variety $(A, \lambda)$, together with a collection of bases $B_n$ of its $p^n$ torsion for every $n$, with the $B_n$ being compatible in the obvious sense; and it's pretty clear that this is the same data as a trivialisation of the Tate module as a $\mathbf{Z}_p$-module.
Comment: Thank you for your answer, really clear! Just a remark. Why does this description hold true only for $(C,\mathcal{O}_C)$ points? What can go wrong if we consider points over a different affinoid adic space?

Points of Scholze's Anticanonical Tower


Are MACs vulnerable to birthday attacks?

Question: Às the title already indicates, I would like to know: Are MACs vulnerable to birthday attacks?
Comment: In a situation where you can get arbitrary messages signed (MACed) you can try to produce two colliding messages with the reduced probability of a birthday attack. So yes they are. But since you normally cannot do that without having the secret key it's most of the time not practically relevant.
Comment: In the principle (MAC is a compression function) there's always a probability of collision. The task is make the probability negligible. Wikipedia (Cryptographic_hash_function) claims "It requires a hash value at least twice as long as that required for preimage-resistance; otherwise collisions may be found by a birthday attack ( Introduction to Modern Cryptography)"
Comment: Please [**edit your question**](https://crypto.stackexchange.com/posts/50085/edit) to describe **what research you have done.** See, sharing research efforts helps everyone. Tell us what research you did, what you found, and why it didn't meet your needs. That shows users you took time trying to help yourself, saves us from reiterating obvious answers, and helps you get more relevant, on-point answers. At worst might help you frame [***"a better question"***](http://crypto.stackexchange.com/help/how-to-ask); at best it might even answer it.
Comment: Related: [***Is HMAC prone to birthday attacks?***](https://crypto.stackexchange.com/q/39303/12164)
Answer:
Are Message Authentication Codes (MAC) are vulnerable to birthday attacks...

Like most things in life, it depends.
Certainly, if you have an $n$-bit MAC, then after about $O(2^{n/2})$ MAC'ed messages, there's a decent probability that you see two different messages $M_1, M_2$ for which $\text{MAC}_k( M_1 ) = \text{MAC}_k( M_2 )$
However, that begs the question: is this observation actually an attack?  After all, the security property of a MAC is "it's hard to generate the MAC of a message you haven't seen"; in the above attack scenario, you've seen the MAC's for both $M_1$ and $M_2$, and so neither would qualify under the "you haven't seen" part.
The pertinent question is "does having two message evaluating to the same MAC actually allow us to deduce the MAC of a message we haven't seen".  For most MACs, it doesn't; there's no obvious way to do this for HMAC, and for nonce-based MACs, the fact that each message was MAC'ed with a different nonce would appear to block any such obvious approach.
However, there is a common MAC where it would appear to be an issue: CMAC.  That is, if we can find two messages $M_1, M_2$ (both a multiple of 16 bytes in length; it is easy to extend this observation to non-multiples of 16 bytes) with $\text{CMAC}_k(M_1) = \text{CMAC}_k(M_2)$, then we know that, for any string $N$, we have $\text{CMAC}_k(M_1 | N) = \text{CMAC}_k(M_2 | N)$.  Hence, if we find such a collision, we can ask for the MAC of $M_1 | N$, and then we immediately know the MAC for $M_2 | N$; this counts as a valid attack.
However, CMAC is the only MAC I can think of with this potential vulnerability.
Comment: Are you thinking of [CBC-MAC](https://en.wikipedia.org/wiki/CBC-MAC), aka ISO/IEC 9797-1 MAC Algorithm 1, when used for variable-length messages despite a cautionary note in the standard? [CMAC](https://doi.org/10.6028/NIST.SP.800-38B) seems to never have been vulnerable to the attack described. [Wikipedia's link to CMAC](https://en.wikipedia.org/wiki/CMAC) now redirects to OMAC; I guess the old name created too much confusion.
Comment: @fgrieu: no, CMAC.  With CMAC, in the case that the message is a multiple of 16 bytes long, the algorithm is: compute the CBC MAC on the entire message except for the last 16 bytes; then xor in the last block and a secret value, and then do a final AES op.  If we have two messages blocking (the output of the final AES is the same), then the input to the final AES must have been the same, and hence the CBC MAC of the initial message xor with the final block must be the same.
Comment: @LuisCasillas: good point,  However, CMAC has the additional disadvantage of having a small internal state, hence you need fewer known message, tag pairs before being likely to find a collision; e.g. you need only $2^{49}$ pairs to have a 1-in-a-$2^{32}$ probability...
Comment: @poncho: That sounds like a special case of a generic state collision attack, applicable to any finite-state iterated construction $F$ that processes variable-length inputs incrementally. If I can find *any* $M_1 ≠ M_2$ such that absorbing these as prefixes yields the same intermediate state, then for all $N$, $F(M_1 \| N) = F(M_2 \| N)$. The CMAC-specific bit is that you can infer a state collision from *any* colliding pair of block-size-multiple messages, and not just e.g. pairs with the same length (because the construction does not use message length).


Query csv tables stored s3 through athena

Question: Recently we started to store our backups in aws s3. It is all csv files that we need to query through aws athena.
We tried to insert the tables one by one but it's taking too long, it is a fair amount of data. Is there any API that we can use or something that is alredy set?
we were about to do something with spark, but maybe there is a simpler way, or something that's already have been done.
thanks
Comment: `We tried to insert the tables one by one` - what does this mean? Create the tables one by one? Athena doesn't support `INSERT`.
Answer: You can simply create an external table on top of CSV files with the required properties.
Reference : Create External Table on AWS Athena
You can also use Glue Crawler and configure it to automatically populate the tables for you.
Reference : Cataloging tables with a crawler
There are different AWS SDK's available (here) to automate your tasks like uploading files to S3, creating athena tables or cataloging tables through glue clawler.


Anti-Sock Puppet Strike Force Needs to Examine Badge Artifacts

Question: Yesterday a sock puppet upvoted a bunch of my answers, artificially increasing my rep.  I was pleased to see that the Anti-Sock Puppet Strike Force detected and canceled this within a few hours.
Of some concern to me is that the sock puppet's activity resulted in two extra badges being awarded to me that were not rescinded (Revival and Mortarboard).  Of minor concern is that the policing apparently canceled slightly more rep (15 pts) than I could attribute to the puppetry.  So, Kojak, if you're out there, please nuke these badges and start checking for badge artifacts in general.  I am "curious" about how the rep inaccuracy occurred, but am "personally unconcerned" about such a small amount of rep.
Comment: @George, badge awarding is expensive sql queries, probably not worth to do automatic recalc for badges for them, I think. If someone ask it, they probably do manual recalc of badges. Reps involve your priviledge on the site, but badges does not.
Comment: Don't worry, there is badge recalculation also. and You will miss same badge when you really earn that badge.
Comment: Good point about badges being just fluff.  I see you are a very dedicated participant, so please rest assured that I do not intend any disrespect by expressing "skepticism" about your theory that the recalc is not done automatically because of CPU expense.  This really does seem like an oversight to me; I await a definitive response from a member of the Anti-Sock Puppet CSI team. :-)
Comment: If so, why did this not take place when the spurious rep got nuked?  Is it a separate process that happens later?
Comment: @George: There just is no "badge" recalc. I can't say a reference right now, but there are many places where it's said (by moderators or the developers) that badges, except _tag_ badges) are (almost?) never taken away.
Comment: @Hendrik Your comment sounds reasonable, though it does, of course, directly contradict YOU's comments.  Still awaiting clarification from Starsky, Hutch, et alia. :-)
Comment: @George: No, it doesn't really. What I meant: Usual badges are _not taken away_. What YOU meant: If you've got an undeserved badge, you _won't get it the next time_ you do deserve it. If you never deserve it, it'll still stick around.
Comment: @Hendrik Well, um, I think I kinda sorta understand, even though, at first blush "there is badge recalculation" (YOU's first comment) and "There just is no badge recalc" (your first comment) seem to be conveying opposite meanings.  I've never understood "meta" very well. :-)  Since no one has posted an answer to my question, I now get the sense that the Sock Puppets must have launched a first strike and wiped out the Anti-Sock Puppet humanoids.  The rep-nuking scripts still seem to be in place--good enough for government work, I suppose. :-)
Comment: [badges badges badges badges badges badges badges badges badges badges badges badges](http://www.badgerbadgerbadger.com/)
Comment: @Hendrik & @George, I said about "recalc badges" because I seen [following answer](http://meta.stackoverflow.com/questions/57824/new-badge-notifications-targets-wrong-post-for-nice-answer/57831#57831) from a developer before, but now I checked it again, the post said that "resync badge reasons" - not a exact term as "recalc badges". So, "badge recalc" is exist or not exist is up to you.
Comment: @George: Now you got your answer - and it even addresses the "almost(?)" from my above comment. And yes, indeed, YOU's formulation in his first comment was a bit imprecise: The _2nd_ part of that comment is the real thing.
Answer: Regular badges are monotonic - they increase, but do not decrease, even if the conditions that gave you a given badge are no longer true.
This is explained in more detail in the Badge FAQ:

The site admin has stated multiple
  times that, by design, badges cannot
  be lost or revoked, unless they were
  obtained by cheating.
However, if the criteria for a badge
  no longer exist — e.g. the post it was
  awarded for is deleted — the next
  award of that badge is negated. When
  badges are awarded, the system checks
  to see how many you're supposed to
  have, and only awards new badges when
  the number of badges you're supposed
  to have is greater than the number of
  badges you have.
As an example, suppose one of your
  answers received 10 up-votes, which
  caused you to earn the Nice Answer
  badge. After you have the badge, that
  same answer is down-voted to a score
  under 10. The Nice Answer badge is not
  revoked. However, the next time you
  have an answer that gets 10 up-votes,
  you will not earn an additional Nice
  Answer badge, because the system sees
  that you already have the number of
  Nice Answer badges that you should
  have.

In certain egregious cases of abuse they may choose to push a full badge recalc on an account, which will reset all badges to what the user's account currently fits, but in general this operation is deemed unnecessary since eventually one might get that extra badge back anyway, and thus is not automated.
One of the reasons minor sock puppet problems do not trigger an automatic badge recalculation is that some badges might be "lost" due to normal processes (downvotes might cause one to lose "good answer" badges, for instance) but the policy is that rather than taking the badge away, you simply do not award it again until they've achieved more than the number they have.  It's the equivalent of choosing between letting someone keep a badge they rightfully earned until they pass the threshold to earn it again, or forcibly ripping the badge off their uniform simply because someone downvoted one of their good answers.
If someone is in a state where they have more badges than are currently valid that's ok.
Because it's ok, it's deemed more harmful to remove those badges due to someone else's poor choices.  Especially if it ends up removing badges that weren't caused by the actions of the abuser.
In fact, if the process was automated, one could use this system to abuse users by finding people with more badges than what they should have, causing some violence on their posts, thereby forcing a badge recalc.
In other words, you have just forced the system to remove the badges from their uniform despite the policy that badges are kept until they are re-earned.
So the process is not automated, and is only employed in egregious acts of abuse.
Comment: I think it is very unlikely that I will ever earn a Mortarboard Badge by my own lights.  So, one day, many years from now, when my granddaughter, by then a member of the Stack Overflow Youth League, looks up at me with wide eyes and asks "GranPappy...How on earth did you ever earn 200 rep points in a single day?!?"  I will be able to reply with a tale of "The Attack of the Sock Puppets," and how those noble Jedi scripts who came to my defense simply refused to rip my uniform, leaving me the Mortarboard badge as a spoil of war.
Comment: @George I think you need to add three more words to your Stack Overflow Youth League group's name, starting with the letters E, N, and T.  Their uniform should be green.  Because, after all, [Stack Overflow is made of people!](http://en.wikipedia.org/wiki/Soylent_Green)
Comment: @Adam Thank you for your very detailed answer.  If you don't mind spending a few more moments on this topic, I would appreciate an elucidation of why the rep removal should have been slightly inaccurate.  The puppet added 176 points; the scripts removed 191.  Let me repeat: I do not care in the least about recouping the 15 pts...I am just curious to learn a little more about the policing process, since I am in the somewhat unusual (I presume) position of having been the "innocent victim" of some minor puppetry.
Comment: @George - I don't have visibility into why you feel there's a discrepancy.  See http://stackoverflow.com/users/645502/george-freeman?tab=reputation to find out where you have all your reputation from.  I would focus on why you believe the puppet only added 176.  However, one possibility is that when posts are deleted, your reputation isn't recalculated.  However, when abuse is detected your reputation is recalculated.  It's possible that you have some previously deleted questions and/or answers that only show up as rep changes now due to the recalc that occurred due to the abuse.
Comment: "Recalc" angle makes perfect sense.  Thanks again for your clear and detailed answers.  I'm happy to have an "unripped uniform," and will sleep more soundly knowing that Justice is being served by existing mechanisms. :-)
Comment: Well, if I can get them interested in things like EPEAT, how about "Stack Overflow Youth League for the Environment and Nature, Too!" (aka "SOYLENT Green")?
Comment: There was talk a while back about instituting regular or triggered badge recalculations. Did this totally fall by the wayside?
Comment: @Ether It was never declined, but it wasn't implemented or deferred either.


How an interface can replace a class?

Question: I created a Method called GetStudentMarks(). The return-type of this method is generic List<StudentMark>.The code works well even when i replaced the List<StudentMark> with generic IList<StudentMark>. How can an interface replace a class while interface contain only the declarations?
Answer: An interface cannot replace a class. It's just a blueprint for a class that has some implementation that corresponds by the guidelines that are set by the interface. So, you mostly will have one interface and than 1 or multiple classes that have some implementation for that interface like so:
public interface IMyInterface{
 IList<string> SomeList { get; }
}

public class MyClass : IMyInterface {
  public IList<string> SomeList {
    get {
      return new List<string>(){ "a", "b" , "c" };
    }
  }
}

Comment: +1, although the term "Contract" is more established. The interface promises that an object can perform a certain kind of methods.
Answer: It doesn't matter if the return type is interface or a solid class. Since inside the method you're returning the full type, the type is casted to the declared return type before returning the actual data so everything works as expected.
public IList<string> MyStrings()
{
  return new List<string>(); // Cast happens here just before return (List -> IList)
}

Later if you require, you can cast the return type (IList) back to the solid class (List) and use it that way.
Answer: Interface can not replace the Class. Interface can create an abstraction layer that hides actual object implementation beyound interface (that's why it's called interface).
Look on Polymorphism for explanation.
Comment: Just to rephrase you a little, it hides or abstracts the *implementation* of what it defines.

How an interface can replace a class?


Recommended TextMate Bundles for Ruby on Rails Development

Question: Can you guys please recommend few textmate bundles that would be  helpful while developing ruby on rails applications
Answer: Kevin Faustino put together a fairly recent list (May 2010) of his favorite Textmate bundles. This list got me started on improving my productivity with Textmate and searching the web for Textmate bundles that fit my personal needs.
Answer: The Ruby on Rails bundle, obvi. The jQuery bundle is also cool if you happen to be using Rails with jQuery.


old emojis in whatsapp

Question: I have upgraded whatsapp on my phone but i dont like the new emojis on whatsapp so the quesition is : Is this possible to get my old emojis back using whatsapp's latest version apk with apktool debugging?
Answer: You can install a WhatsApp mod like GBWhatsApp. Then, activate "Old Emojis style" in settings.
Answer: You can try downgrading your WhatsApp version, by downloading an older APK.
before you download the apk make sure to uninstall WhatsApp.
After that, download the desired apk from here
You should then be able to go thru the regular registration process in WhatsApp.
To make sure it doesn't automatically update the app, go to the play store, search for 'WhatsApp' in the search bar, press on the WhatsApp icon, then press on the three dots menu on the top right of the screen and deselect 'auto update'
Note: WhatsApp might give you an error telling you to download the latest version.
Also note: just because you will now have the older version of emojis, doesn't mean that the recipient will see them in that way. The opposite is also true, if someone sends you an emoji that came with the latest update, chances are, that you will not be able to view them.
I'm not responsible if anything goes wrong.
Answer: What you want is not possible. You want the latest version of the app, but the old emojis. That is impossible for anyone but the developer.
When an app is built, all its components are consolidated into one project. It is not possible for the layman to change any one component of the project. The previous emojis were in one project, while the modified emojis are in another project. You cannot just change the emojis and keep the rest at the latest version.
If you are okay with downgrading, then you can try what @Abochur has said, or simply uninstall the updates. Otherwise you'll have to get used to the new emojis.

old emojis in whatsapp


bitcoin miner compatible with nvidia

Question: I would try to start mining Bitcoin into a mining pool, and I'm looking for a client compatible with Linux (if it has a GUI would be better) and that admit to use my Nvidia GTX 860 graphic card.
Any suggestion?
Comment: You're a bit too late for bitcoin mining with an individual graphics card to be profitable. Look for cuda-based miners (I think there is one called cudaminer).
Comment: Because bitcoin mining is now done by dedicated hardware - ASIC miners. The difficulty is now too high for a normal PC CPU + gfx card to make it profitable considering power consumption and other things. See https://en.bitcoin.it/wiki/Non-specialized_hardware_comparison
Comment: why i'm too late? I would use graphic card and some cpu cores (if it's possible).
Comment: Could you please convert that to an answer so that schmucks like me who go around hunting for unanswered questions don't have to look at this one any more.  ;-)  (And I'll upvote if you drop me a note and it's a good one too!)
Comment: I think you need ASIC computers, a specialized hardware to mine.
Answer: Answer copied from comments:
Because bitcoin mining is now done by dedicated hardware named ASIC miners,  the difficulty is now too high for a normal PC CPU + GPU to make it profitable considering power consumption and other things.
See http://en.bitcoin.it/wiki/Non-specialized_hardware_comparison for further info.
Answer: Bitcoin's were so profitable at the beginning that specialized hardware have been developed that can mine bitcoins. This hardware is based on an Application Specific Integrated Circuit or ASIC. There are different generations of ASICs that can do more in less time as they become more recent.
It is almost impossible to get any help in setting up a nvidia GPU based bitcoin miner because the folks that develop the software no longer support what they consider a unworthy configuration. You can get low end ASICs below $40.00, perhaps lower. I saw one on Alibaba for $25.00. These low end ASICs are built to plug into a USB hub or port. The simplest way to begin mining bitcoins would be to buy one or more of these USB ASICs and then use software like BFGMINER which can be found for windows, MAC, and Linux.

bitcoin miner compatible with nvidia


Conservation of energy in a rigid body

Question:
"One end of a rod of uniform density is attached to the ceiling in such a way that the rod can swing about freely with no resistance. The other end of the rod is held still so that it touches the ceiling as well. Then the second end is released. If the length of the rod is $l$ metres and gravitational acceleration is g ms−2, how fast is the unattached end of the rod moving when the rod is first vertical?"

Tangential Velocity of a Rotating Rod
This question has been asked before and answered using moment of inertia and GPE. My question is when deriving the answer, it seems as if the GPE of each infinitesimal element is not directly converted into RKE but the whole system's GPE is converted into RKE. Would this be down to some conservative forces between infinitesimal elements in the rod that affect the energy of each element but such that the overall energy of the rod is conserved? I can't seem to wrap my head around the fact that conservation of energy is not held on each infinitesimal strip of mass rho*dx.
Answer: Yes, there are internal forces that hold the rod together. If there were no internal forces (imagine if the rod suddenly turned into sand), every piece of the rod would simply fall straight down.
Comment: @DanielWilliamsRuiz It is possible to calculate the internal forces, but if we treat the extended body as rigid, it simplifies things greatly
Comment: Is this why it would be impractical to consider the forces/energy on that infinitesimal strip as we do not know them all but we do know the relevant forces on the extended body?

Conservation of energy in a rigid body