DVD Image vs DVD Copy

Question: Is making an image of a DVD disk faster than copying DVD on disk?
Answer: Yes, making an image on the harddrive will be faster.  The bottleneck in the above situation is DVD write/read speed.  Writing to the harddrive is significantly faster than writing to physical media like DVD's.
So, you have the two scenarios:
1)  Read from DVD and write to HDD.
If your drive is a standard 16X DVD-RW drive, then this should take about (4.7GB / 22MB/sec) = 3.7 minutes.  We can consider the HDD write speed to be negligable because it will be done at the same time as the reading of the DVD and can easily keep up.
2)  Read from DVD, store temporarily on hard drive and finally write to DVD.
(if you have 2 DVD drives than some of this can be done simultaneously while simply using a buffer in memory)
Similarly, in this case you have to do the same thing as above and write back to the disc.  If you write speed is also 16x then you are looking at a total of 7.4 minutes.
In the first case you only have to read from the DVD once where as in the second, you'll have to both read from the DVD, write to the hdd and finally write to a DVD which takes more time.
Comment: Is there any performance comparisons available? I'm just curious to know how much faster. :)
Answer: In theory making an image of the DVD should be faster than just copying the files and directories, since the image copy is done on a sector-by-sector basis and does not waste time on following the files through the file system.
There are no numbers that I could find for reading the DVD, but some burner programs claim that writing an iso is 6-7 times faster than copying the files/directories. It seems logical that the reverse operation should also be faster for the same reason.

DVD Image vs DVD Copy


What should I be looking for in a heart rate monitor?

Question: What are the most important points I should look for in a heart rate monitor? I am looking at only using it when I work out (so not a fitbit, etc for sleep). I want a hrm and not just a glorified pedometer. I want to make sure its accurate, can tell me total calories burned, and optionally uploads to computer and/or has a chest strap.
Comment: A shopping request would be if Kyra asked what monitor should she buy. Instead, she's asking how to determine what to buy. See [Q&A is Hard, Let's Go Shopping](http://blog.stackoverflow.com/2010/11/qa-is-hard-lets-go-shopping/), which has examples of good and bad versions of this question. (This is the "good" version. +1)
Comment: This question feels more like a shopping request, as you seem to know pretty well what you are looking for in a HRM.
Answer: The main things to look for in a heart rate monitor for exercise workouts is its accuracy, readability, functions and ease of use.
Accuracy - Check your radial pulse and compare it to the heart rate monitor for accuracy.  At rest you can check it for 60 seconds.  During exercise you can check your pulse for 6 secs and multiply by 10.  If you need a heart rate monitor for cardiac rehab, ask your healthcare practitioner for recommendations.
Readability - If your vision is a factor make sure that the display is large enough and clear enough for you to read it easily while exercising.  A night light or backlight function can help readability especially in dim light.
Functions - As you mentioned you want estimated calories burned and the ability to transfer data to your computer.  Other considerations are the ease of set up, ability to set target training zones, alarms or percent-of-max heart rate display, lap timers, water resistance, and the ability to change the battery by yourself vs having to send it back to the manufacturer for a new battery.
Ease of Use - Having more functions than necessary can complicate its use, so choose according to your goals. Consider the chest strap comfort and ease of application.
Price and warranty are also a consideration.
Answer: I think it comes down to preference as long as it takes your heart rate accurately.  I prefer the HRMs that provide a strap that goes around your chest.  Most machine will pick up on this so you won't always need your watch (unless you have timers set up on them).
You can test the watch by finding your pulse (in your dominant hand) on the thumb side of your forearm near your wrist.  Feel your pulse and count.  If you count for 15 seconds multiply by 4 and then look at the monitor and see if it is close! Counting to 60 will be more accurate (no need to multiply by anything since you've counted for a minute).
Answer: I think it depends on what you are trying to achieve.  If your doctor tells you (as mine did me) that you need an HRM, that means, Doc is concerned, you should be too, and so, accuracy is extremely important.  However, if you are casually measuring HR and accuracy isn't important, or, you have other means to account for accuracy of a particular device, or, you can change the method of calculating HR, then you have lots of options.
Right now, there are two popular methods on the market to measure HR.  One is optical heart rate monitoring, which uses LED to measure the expansion and contraction of capillaries, which do so because of the heart beats.  The problem is that certain exercises can cause muscles and tendons to affect the contraction and expansion of capillaries, in addition to the action of heart rate, and so, OHRM method is not usually reliable when used during some workouts.  Weightlifting, martial arts, combat fighting, some calisthenics, etc, anything which uses the arms, can garner an inaccurate reading.  Walking, resting, some swimming, some yoga, etc which do not generally use the arms, can garner a more accurate reading.
OHRM is mostly found in wrist-worn devices, like FitBit.  The latest news reports show these devices to be as low as 60% accurate, and cite the reasons I mention.  Read the sources to find the details.  These are convenient and comfortable devices, and as long as you know the limitations and can work around them, these are fine.
The other HRM technology are the chest strap-ons, these usually go around the chest and measure electrical impulses, much like an ECG machine.  These are much more accurate, but many people find them to be uncomfortable, and the devices are devoid of the many other features a wrist-worn device has.
My guess is, if you find a device which uses chest strap-on for HRM combined with wrist-worn for data gathering and other features, that would be an ideal compromise when you need to measure HR during those exercises which are known to garner inaccurate readings.
How accurate are Fitbit trackers?
Just How Accurate are Fitbits?  The Jury is Out
Validity of Consumer-Based Physical Activity Monitors for Specific Activity Types
Here's How Accurate The Fitbit Alta HR Actually Is
Note that the BuzzFeed article, the last one, went on the cheap and compared their results with a chest-worn device, which they claim to be "scientifically more accurate".  However, they do point out an important warning: that FitBit specifically states that their devices are not to be used for medical or scientific purposes.  That means, Fitbits, et al, are for entertainment purposes only.  You'd have to get a device which IS meant for such purposes... and gue$$ what?
My doctor told me the devices are great, but for accurate HR monitoring, short of lugging around an ECG on a tricked out gurney, a watch and two fingers is best, if not convenient.  He wanted my HR within ranges, and so, accuracy for me was not important to me as it was for one of his other patients who had severe weight and heart issues.  In that case, his patient had to wear devices which were needed for accuracy, and had to have insurance take care of the costs.


find the minimum difference between the factors of a number

Question: Given a number c, what is the smartest way to find |x - y| such that x * y =c and |x - y| is minimum
Comment: Need more clarification: whether $x, y \in \mathbb{R}$ or $\mathbb{C}$.
Comment: x, y are inegers
Comment: I don't think this is smart enough, but one approach is to make a sorted list of the divisors of $c$ (see http://www.velocityreviews.com/forums/t343209-math-need-divisors-algorithm.html) and then do a binary search for the divisor that is closest to $\sqrt{c}$.
Comment: What does "smart" mean?

How large are your numbers?  If $c$ is very large, then no smart  (i.e., fast) way of finding nontrivial $x,y$ with $x*y=c$ is known.
Comment: I agree with Goldstern, $c$ should not be very lagre.
Answer: As @Goldstern commented, if you don't have the factorization of $c$, then in general you can't even necessarily find non-trivial factors.
Even assuming you're given the full prime factorization of $c$ this looks like an optimization version of the partition problem, so I think an exact solution will still be hard in the most general case.
Write $c=\prod p_i$ as a product of primes (allowing repetitions), then your question is finding a partion of the multiset $S=\{\log p_i\}$ into $S1$ and $S2$ so that
$|\exp(\sum_{S1})-\exp(\sum_{S2})|$ is minimized. Since $\sum_{S1}+\sum_{S2}$ is fixed, this also corresponds to the minimum of $|\sum_{S1}-\sum_{S2}|$.
While the problem is usually posed as a discrete one, I expect that some of the algorithms referenced on Wikipedia can be applied effectively.
Comment: And conversely, given a hard instance $S \subset {\bf R}^{> 0}$
of the partition problem, one can find $C>0$ and primes close enough to $\exp C\cdot S$ that their product is a hard instance of the nearest-factor problem at hand.
Answer: I will suggest the following:
First, assume $x,y \in \mathbb{R}$, as the line $y=x$ and the hyperbola $y=\frac{c}{x}$ intersect, denote the intersection coordinate as $(x_0,y_o)$. If $(x_0,y_o)$ is an integer coordinate, then $|x_0-y_0|=0$ is the minimum.
If $(x_0,y_o)$ is not an integer coordinate. then consider the  $x$-coordinate of $x_0$, say $[x_0]$ and $\lceil x_0 \rceil$, the greatest and least integer respectively. Now look for the $y$-coordinate $\frac{c}{[x_0]}$ and $\frac{c}{\lceil x_0 \rceil}$, If any of these $y$-coordinates is an integer, then just take the difference  $|x_0-\frac{c}{[x_0]}|$ or $|x_0-\frac{c}{\lceil x_0 \rceil}|$ , one has the desired result, If none $\frac{c}{[x_0]}$ and $\frac{c}{\lceil x_0 \rceil}$ are integer, then like before repeat the process, this time consider $x$-corodinates  $[x_0]-1$ and $\lceil x_0 \rceil +1$ and proceed similarly. Once one knows $c$ before, then it is  easy to proceed.
The main thing is one has to know divisors of $c$ to make the above process, quick. Also $c$ has to be small integer, else, there is no smart or easy way.


Editor invited after accept minor revisions required

Question: I sent an article and it was accepted minor revision required. After resubmitting the paper the status appeared editor invited and has not changed in more than a week. The first time I submitted it, they just assigned an editor. What does this mean?
Comment: It means you should chill out.
Answer: To wait and not to worry.
Editor might be busy to handle your submission.
You might expect that since it is a minor revision, then it will be accepted almost immediately. Sometimes it is indeed the case. But this depends how efficient the journal is.
Comment: But this depends on...?


Is it easy to digitize in ArcGIS using the Wacom tablet?

Question: I do just enough digitizing (and touching up/ drawing when post-processing) to perhaps warrant the purchase of a Wacom tablet. Just wondering how well it plays with ArcGIS. What are your experiences? Is there a learning curve. Can the tablet and pen replace the mouse all together?
Comment: I should have mentioned that this question pertains to the Intuous or Bamboo tablets and the likes not the interactive display.
Answer: I have been using a wacom tablet with ArcGIS for the past 5 years and have found it to be incredibly useful.  I have only used the Intuous 3 (A4) but the ability to program the 8 shortcut keys as well as the trackpads has saved countless repetitive hand trips to the keyboard - and when you are capturing a lot of little areas of data this can be quite some distance.
However, by far the most beneficial aspect is that your hand rests in a more natural position, rather than rotated (like you get with a mouse) and so you can use it all day everyday, and you do not get any pains in the hand or higher up in your arm.  I no longer use the mouse for any of my applications because the tablet is so easy to use once you have got used to it.
If you are capturing lots of data and need to be returning to the keyboard a lot then you should seriously consider purchasing - at around $400 it is well worth it.
Apologies if I sound like an agent for Wacom, I am not and the same would go for any tablet.
Comment: Would you recommend the big A4 tablet or would be A5 enough? My concern is that A4 model will take all the desk space.
Answer: I use mine all the time with ArcGIS Desktop.  The learning curve isn't as steep as you'd think.  It becomes much more natural to draw on the canvas than trying to use a mouse.  I've noticed that ArcGIS 10 seems designed for the Wacom tablets so it makes it very easy to work with.
My productivity goes up using the Wacom tablet, the quality of my work goes up and my arm doesn't hurt like it does with a mouse.  GIS and tablets should go hand in hand.
Comment: Thanks James. All positive so far. I am excited to get one.
Answer: We've used the Wacom Intuos 4 for a couple of digitizing jobs in the last year, and had a really positive experience.  We've used it with both ArcGIS 9.3 and 10, no conflicts or other problems there.  It took a day or so to really get into the swing of using it properly, but once past that learning curve, I'd say it improved our productivity significantly.  I'd also say it helped in the area of ergonomics - much less wrist/hand strain than using a mouse.
That being said, it hasn't replaced the mouse for everyday use for us.  Didn't really get into the shortcut buttons, but I can definitely see how they might be useful.  It took some minor tweaking of digitizing settings in Arc to make it work just right.  Not sure if this applies to you, but we had some minor problems running Photoshop and Illustrator simultaneously with the tablet, but I understand there's a fix out there.
All in all, well worth the $300 or so it cost us.
Comment: What size of tablet did you use? L (A4) or M (A5)? Which size would you recommend?
Comment: Ours is a smaller one, the total size of the tablet is around A4 and the usable space on it, ie. the digitizing space, is probably closer to A5.  It has been fine for our heads-up digitizing needs, we haven't needed any bigger.
Answer: I've seen the Wacom used by a few Photoshop expert friends, and they really like it. Just be sure to get a big enough model, as the small ones are tough to use on a high resolution screen.
Answer: "Just wondering how well it plays with ArcGIS. What are your experiences? Is there a learning curve. Can the tablet and pen replace the mouse all together? "
I have used Wacom technology for over three years (IBM ThinkPad and also experimented with their interactive penable monitors). Most of my work is in Public Safety (Search and Rescue, Law Enforcement).

It "plays" very well with ArcGIS 10, especially with the new and more powerful Editor environment (editing polygons!!!). I think Esri had such tablet/penabled technology in mind when they developed the latest release.
There is not much of a learning curve at all...
However, you might want to look at how other people have customized their settings with the pen in the ArcGIS editing environment to take full advantage of the technology. Then you can replace the mouse for most functions.

Hope this helps.

Paul D.
Answer: Our soil scientists like using it but when you have a really large datasets that can became an issue. We have a large dataset and they have to make line change with topology and it takes them forever for the topology to finish its work. Thank God I don't have the Wamcom tablet. They just hating it now and wish they could have their workstation back. They are not sure if they will replace Wacom. I feel sorry for them. They are frustrated because when you load ArcGIS to their Wacom tablet, it is really realy SLOW. They are on network server.
I have 2 dual monitor's workstation and I am glad I did not get it because I was not sure how will it work with my time doing GIS work.  It saved me from getting frustrated. So, I am not sure if anyone has any experience with large datasets on Wacom tablet. Anyone ?
Comment: Thanks. Good to know. I did not even consider the tablet with the display. I've read some reviews about it being cumbersome and people having to look at the tablet rather then the screen. Is this what your scientists are using? I already have dual monitors and will be keeping my mouse (depending on the level skill i acquire with the tablet) I am thinking of the large Intuos tablet. At first i will only be using it for digitizing in ArcGIS and drawing in CorelDraw but will also try it as a primary pointing device.
Comment: just to be clear, and hopefully I'm not too late to the party to get an answer, but are you saying a wacom digitizing tablet with large datasets and topology is painfully slow, while a mouse with the same data is not?
Comment: Matt, no your not too late. I believe so they have tried both ways and they are not happy with the results. They do not have a workstation like I have and it gives them the limit to run a large datasets. You might want to find out others. Remmeber I work for the Government and they like to give us cheap computers. For the private sector, you might want to customize what you like like a high end workstation with the monitor. I would stick with the high end workstation and use with my mouse because it is more powerful. Maybe find out where you can go and have yourself to see what it looks like.
Comment: They said when you digitize with the pen, and sometimes when you want to change a line it gives them some sort of shifting when you try to move or change the line. I think this is what gave them frustrated.  But If I were you it is better for you to go and have yourself to see it so you will know what it look like, Matt.
Answer: We have a detailed blog post on our experience using the Wacom DTU-2231.
http://letters-sal.blogspot.com/2011/05/digitizing-wacom-way.html


Topic models for Relevance Prediction

Question: Suppose I have data in the form of  Query/Document Pairs, along with corresponding relevance scores (or class labels). Is there a way to use topic modeling to devise a model so that later given a query and a document, we can predict its relevance score?
Comment: Topic modeling might be a way to learn a representation of your text before applying supervised learning.  However you might be able to use something as simple as tf-idf vectors
Answer: Certainly. A part of topic modeling output is typically some vector for each document describing it as a distribution over the topics in your model. You can use these as continuous-valued predictors for a classifier trained with the labels you have. I've done this before, but, depending on the domain characteristics of your problem, it may not be the best approach, but it is certainly a testable one!
Answer: Possible, yes, but why do you want to do this?
Topic modelling is a method of unsupervised learning with all it weaknesses.
With the type of data you sketch you can used methods of supervised learning that will be much more stable, less prone to overfitting, and more reliable in the long run.
Comment: [Supervised Topic Models](http://papers.nips.cc/paper/3328-supervised-topic-models)
Comment: @Emre: Interesting paper. Unlike unsupervised LDA, supervised LDA hasn't become popular, and even without trying I have some ideas why this is so.

Topic models for Relevance Prediction


Parity Ethereum on Windows : Corruption block checksum mismatch - fails to launch

Question: I have installed Parity Ethereum on my Windows 7 (64 bits) laptop. It has worked fine for some weeks. Today, I was forced to hard-reboot my laptop for some reason, while Parity wallet was running. Due to the hard-boot, there was an auto-run of ChkDsk at restart that did some clean-up. I'm trying to relaunch Parity Ethereum, it attempts to launch & I see Parity icon in my system-tray. But after a few seconds, the icon disappears & Parity also doesn't show up as a new tab in Chrome browser. On launching Parity via command line, I receive the following error:
<code>thread 'main' panicked at 'failed to update version: "Corruption: block checksum mismatch"', C:\bot\slave\stable-dist-rustc-win-msvc-64\build\src\libcore\result.rs:868
</code>
Can anyone please guide me about how to resolve this? Thanks in advance !
Answer: Your database is corrupted. Run
<code>> parity.exe db kill
</code>
And then restart parity. This will delete your chain and state and resync, which should take a couple of minutes.


Where can I go to read up on encryption methods used in Bitcoin?

Question: Where can I go to read up on encryption methods used in Bitcoin? I am particularly interested in the idea that I can use a private key to sign something and it proves to the world I have the private key but yet does not reveal the actual key.  This is a topic of mystery to me, how this is done.
Answer: Here's a short explanation that might help you understand it. It's grossly oversimplified but just designed to help you get the general idea.
Imagine a world in which multiplication and addition were irreversible. That is, division and subtraction do not exist. It is not too difficult mathematically to create a world where division and subtraction are trillions of times more difficult than multiplication and addition, so for practical purposes, division and subtraction are impossible.
Now, let's say we all agreed on a very large number. Call it G. It's some big number we all agree on.
Now, you can pick a random number and store this someplace very safe. Call it your "private key", S (for secret). Now, multiply it by G. Call the result your "public key", P. You can tell anyone your public key. Since they can't divide it by G, your private key will stay private.
Now, say you want to "sign" something, O. What you do is you take that something, add your secret key to it, and publish the resulting number. So you publish: O+S, that's your signature
First, nobody can tell your private key from that number. They'd have to subtract, and that's not practical. And nobody else can produce that number, they'd have to know your private key to know what to add to O.
So all we need is for someone to be able to prove that's the "right" number and we're there -- and they can do that. Why? Because G * (O+S) = G * O + G * S.
They know what you claim is O+S ... the signature. G*S is your public key. And they know O. So with just some addition and multiplication, they can compute both G * (O+S) and G*O + G*S. So they can check if the number you published really is O+S if those two are equal, thus that the person who computed it knew your private key, and thus it functions as a signature.
The challenge, of course, is to create systems in which multiplication and addition are possible but subtraction and division are not. And there the math gets complicated. Bitcoin uses a system where division requires discrete logarithms and a change to the algorithm so that it doesn't matter if addition is reversible.
Comment: Excellent explanation, thank you.  On another note I was reading on the wikipedia link you gave and it said this: "The hardest ECC scheme (publicly) broken to date had a 112-bit key for the prime field case and a 109-bit key for the binary field case. For the prime field case this was broken in July 2009 using a cluster of over 200 PlayStation 3 game consoles and could have been finished in 3.5 months using this cluster when running continuously (see [17])."  Am I correct when to think that Bitcoin uses 2^80 bit key?
Comment: Bitcoin uses 256-bit keys, specifically [secp256k1](http://www.secg.org/index.php?action=secg,docs_secg).
Answer: Wikipedia is a wonderful source for this. First, note that there is no encryption in the Bitcoin protocol - there are techniques from the more general field of cryptography, such as digital signatures and hashing.
Digital signatures are an example of public-key cryptography, which can be used not only for digital signatures but for a type of encryption which is different from traditional symmetric encryption.
Specifically, Bitcoin uses Elliptic Curve DSA for digital signatures and SHA-2 for hashing - here is a nice review of how they are used.
You might also want to read up on RSA which is a very well-known public-key cryptosystem, though not used in Bitcoin.
Comment: What encryption is used for the wallet passphrase encryption in the Bitcoin.org client?
Answer: Small clarification - encryption is generally a topic about obscuring data so it can't be read. If you are interested in the algorithms of signing things, you are not looking for encryption, but you are looking for signature algorithms.
Signature algorithms are generally a topic about mathematically showing that only you could've sent the data, while not necessary obscuring it.
For the signature algorithms used in Bitcoin:

Google for ECDSA.
Wikipedia entry for ECDSA.
Bitcoin Wiki entry for ECDSA.

Generally, look into topic of Digital Signature Algorithms in general, and Elliptic Curve Digital Signature Algorithm in particular.
This topic is a field of cryptography, and is not Bitcoin specific. If you have more questions regarding it, you should check out Crypto SE.


How does inflection evolve in languages?

Question: Is there an explanation, or maybe even an observation, how inflection appears in a language? With inflection I mean phenomena like the germanic ablaut ("man/men", "Mann/Männer") or the inflection in arabic. These declension or conjugation systems do not seem to be causally related to fusing suffixes to a word root.
Comment: "man/men", "Mann/Männer" is not ablaut, but umlaut. It is the result of the assimilatory palatalisation of the stem vowel before a suffix with a front vowel.
Comment: Just as syntax can become morphology by fusion, phonology can become morphology by fixing forms. Thematic vs athematic roots in Latin are an example.
Comment: Inflection as opposed to derivation is not about how it is expressed, it is about *what* it expresses (case, tense, agreement, etc.). Inflection in Arabic is primarily accomplished with regular affixation. Are you asking about inflection, or about the history of umlaut and Semitic root-and-pattern morphology (two unrelated phenomena)?
Answer: This question has been dealt with in literature on grammaticalization. The Wikipedia entry has all the detail to get you started on further research.
In short, there are a number of processes through which lexemes lose their original meanings and through processes like enclitization become morphemes. We can even see some of these in progress as in the English will going from will=want to 'll.
This type of development has been famously summarized as:

content word → grammatical word → clitic → inflectional affix
Comment: [Diagram here](http://www.umich.edu/~jlawler/Grammaticalization.pdf).
Comment: It might be better to state this as a hypothesis rather than as a fact.
Comment: You are correct. Although the grammaticalization process is well attested for individual morphemes, it is more of a supposition for the entire morphological system of highly inflected languages.


How to check connection string in SSMS2012?

Question: I'm connected to database. I use db by Management Studio 2012 Express. Can I check connection string by click something in Management Studio?
Answer: Within SSMS, I'm not sure there's an easy way to do that.  But a simple query will return you the information (without the password of a connection string, obviously):
select
    'data source=' + @@servername +
    ';initial catalog=' + db_name() +
    case type_desc
        when 'WINDOWS_LOGIN'
            then ';trusted_connection=true'
        else
            ';user id=' + suser_name()
    end
from sys.server_principals
where name = suser_name()

Note, db_name() will return the current database name if there is no parameter specified, so that is dependent on your current scope.
Comment: just for info: in SSMS 2010, the view sys.server_principals doesn't exist yet. But we can use the table syslogin (if I recall correctly)
Comment: I am new to SSMS. I created a new query with above code and ran it. It says "query executed successfully" but where would I find actual the results? Output window only shows "app exited with error code 0".


Responsive web parts possible?

Question: Is it possible for a web part to dynamically resize across a web part zone depending on the size of a computer screen the site is being displayed on?
Answer: Yes... this link describes the responsive grid in Sharepoint.
Comment: Please don't add just a link as answer to a question. If the link breaks, the answer you provided will not be useful for future visitors. Provide an answer of your own and use the link as [reference](http://sharepoint.stackexchange.com/help/referencing). If needed, you can block quote the content from your link. More information is found in our help center, especially [How do I write a good answer](http://sharepoint.stackexchange.com/help/how-to-answer)

Responsive web parts possible?


How to control urine while racewalking?

Question: I can walk 5 km at most, and then I have to urinate. When I start walking, I have an empty belly, but I cannot control urine buildup. How do professional racewalkers handle this? I see in videos that racewalkers drink water during the race and still walk for at least 1 hour (50k racewalkers walk for 4 hours!), never stopping at the restroom! Please help me as this is a hurdle for me!
Comment: It has been almost a year since you posted this question, so not sure if you have found a solution yet. However, it does look like you are not alone. [Athletic incontinence](http://en.wikipedia.org/wiki/Athletic_incontinence). You might want to seek medical help.
Comment: after searching didn't find anything for How professional handle this but check this [link](https://www.racewalking.org/long.htm) maybe you already may have.
Answer: That does seem to be a medical condition.
Personally, from doing long-distance races (running/triathlon), some for 7+ hrs there is usually not much issue for less than 4 hrs. On a 7hr race, I will stop for 1 bathroom break, but do know some (especially more competitive folk) that will urinate on the go to save time. The Videos are also edited to hide these things, there was a pro cyclist that was captured dropping back from the pack and urinating from his bicycle this year without it being edited out but it is likely because it was being streamed live.
Typically, I take in a bit less liquid than I sweat out and drink a whole bunch immediately after the races. So when you are active, all the liquid you are taking in does not only end up as urine but also sweat.
First thing, I would get it checked out. If there is nothing wrong, then consider taking a bathroom break or urinating on the go if you really have to. If you do choose to go that way, remember to pick up extra water at the water stations and rinse it off...

How to control urine while racewalking?


HP Pavillion dv5 Notebook Screen REpair

Question: My screen only comes on when my screen is half way up and it sometime turns off or turns white I think I need to connect a loose wire from the screen but how do I open the laptop to reconnect the screens loose wires? I have an infinity screen with no screws on it.
Answer: It's normal that the screen doesn't have visible screws. Opening up a laptop normally starts with unscrewing the body.
Here [PDF Warning] you have a direct link to the HP Pavilion dv5 Maintenance and Service Guide.
In there you will find exactly what screws there are, and where they are located, and in which order you have to unscrew them.
Good luck!

HP Pavillion dv5 Notebook Screen REpair


Is it common for character traits to be expressed in the way a character fights? If so, how?

Question: For context, I'm writing a fantasy story.
Comment: Character traits should be expressed in *every* action a character takes. Fighting is just one of many situations where character traits affect a character's action. So please don't define characters solely by their fighting style (unless, of course, they are unnamed mooks / redshirts who have no role in the story other than serving as sword-fodder for more relevant characters).
Answer: This is very common in Japanese Anime/Manga. Every fighter may have his own fighting style, and that style would reflect traits like treachery or bravery. This is probably better expressed in graphic than in writing, but in literature this is used too.
Here are the things you can pick for your characters:

Weapons choice (sword/hammer/bow/daggers)
Direct confrontation vs evasion vs fleeing
Careful planning vs rushing in
Improvising, use of "props" like rocks, sand, water
Wounding the enemy minimally vs dealing mortal blows vs maiming
Stopping when the opponent is down vs pressing on with advantage
Comment: This is the best, I'll use that as well XD. Good luck @Avik Mukherjee
Answer: I would say yes to that, given that whenever there are superhero fights in movies, they always say something to go along with what they're doing, but that shows their personality. Take Big Hero 6 as an example, when GoGo is wheeling around and fighting the Kabuki mask guy, she says "Woman Up!"  She said that earlier in the movie when Hiro was presenting his microbot idea.
So yes, I think a characters' fighting style should express their personality.


Lufthansa and transfer to flight on Sun Express

Question: I am travelling to Imir from BHX with Lufthansa and will change flights in Munich. Lufthansa have changed the Munich to Izmir flight to Sun Express, their partner airline. My question is - do I have to check my hold luggage in at BHX only, or will I have to check it in again from Munich to Izmir?
Comment: If it's a single ticket, your luggage will be checked through. No need to recheck in Munich.
Answer: Barring places where you need to do customs declaration at an intermediate point of your journey (such as when your final leg is intra-US or intra-Japan) and barring connection times in excess of 24 hours, your luggage will be checked through to your final destination with almost absolute certainty.
In your case, having to recheck your luggage on a UK–MUC–Turkey itinerary would be exceedingly annoying as both check-in desks and luggage reclaim are landside of passport control; however, as you are transferring non-Schengen to non-Schengen there is no point in you entering the Schengen area for such a small thing. It would greatly disrupt operations and would make the connection much harder for those needing a visa to enter Schengen. So Lufthansa and Munich airport make sure that this type of trip can be done without rechecking.
Munich airport's terminal two is basically one long concourse with two levels: a lower Schengen and an upper non-Schengen level with immigration checks at points where you can change levels. Coming from another EU country, you don't need to go through any additional security, so you really just get dropped off in that long concourse and can immediately navigate your way to your departure gate. (The satellite terminal acts as little more than an extension to that long concourse connected to the rest in the middle still separating Schengen and non-Schengen.)
If either of your flights happen to arrive or depart from terminal 1 (I think I saw Sun Express depart from there at least once) that still doesn't change the general picture as there is an airside connecting bus that connects the non-Schengen gates of T1 and the non-Schengen concourse of T2.


Counting Sefirah in a made up language

Question: Can one fulfill the mitzvah of counting the Omer by counting in a language that only he/she understands? What if a few people understand? An entire goup?
Comment: @Mordechai B. I'm assuming you mean, "If I say 'flippity floppity moozidie whatchit', and intend to be saying, 'Today is the thirteenth day, that is six days and a week, of the Omer', am I yotzei?
Comment: Take Elvish, for example. It's a very well-thought-out language, with an extensive vocabulary and grammar rules. Numerous people can speak Elvish.
Comment: In massechet Sota, Mishnayot list kriot, if in Lashon Hakodesh or in Kol Lashon. here there is no reason to think that it might be in LHK. count is an action, not a lecture.
Comment: Similar: http://judaism.stackexchange.com/q/15763 http://judaism.stackexchange.com/q/7017 http://judaism.stackexchange.com/q/59223
Comment: I don't think one is required to say the count in Hebrew. From my recall, I think even sign-language (which some refer to as "remiza" - signaling) is a valid means of counting the Omer.
Comment: @Mithrandir יפה הדברים לאומרם :) obviously all languages evolve and are "official" when a lot of people say the same thing to mean a particular thing. Elvish is thus arguably no different from any other language, English, French, Sanskrit, etc. However, the OP seems to be asking about a "language" spoken by only one person. If not, the question is where do you draw the line.
Comment: And would R. Nimoy have said Klingon is a valid lashon?
Answer: Lichorah this would have the same halacha as what is defined as a lashon in nedarim, so lashon ilgim, i.e. local slang dialects are ok, but anything less than that not.
Answer: Misvara...
From a psychological perspective, it would appear that what constitutes a language is where you have at least one or two people who think in that language.
For example, the rarest language in the world used to be a Celtic language that was only spoken when 2 elderly sisters met, it is obvious that is a language and could be used for sephiras ha'omer.
Also, there was a case of twins who grew up in an isolated area of Canada and who invented their own language. This is lichorah also a language which would allow them to count sephiras ha'omer (I.e why should they be excluded from counting sephiras ha'omer just because they made up their own language?).
On the other hand, if you can speak Elvish this probably does not qualify you to count sephiras ha'omer in Elvish because there is not one single person in the world who thinks in Elvish, so you have simply agreed with other people on a secret code way of speaking, which does not become a language.
Comment: a) Sevaras atzmo. b) Of course you can, because there are people who think in Spanish.
Comment: Language is a model of how we put the world together. Therefore if there are people who put the world together using a language, it acquires the status of a language because it is used as a model of the world. The unfortunate who thinks in gibberish has no mental model of the world. Native spanish speakers model the world in spanish.
Comment: The mentally unstable person does not put the world together. That is why they are mentally unstable. I do not have a source, this is sevaras atzmo, but I think it is a reasonable proposition, and I am not sure what other definition you could use to delineate when a language achieves the halachical status of a language and when it does not.

Counting Sefirah in a made up language


How does the LED stumps help in Cricket?

Question: In recent matches I can see that LED stumps are used in twenty twenty world cup. Heard that it is very costly. Why do they use that? Does it help for anything or only for fun?
Answer: When the LED stumps were first used in the Big Bash League, its Senior Manager had this to say:

"These light up stumps are all about enhancing the spectator
  experience during BBL matches and ensuring that the BBL remains highly
  entertaining for the fans," BBL Senior Manager Anthony Everard said in
  a statement.
"The stumps do not have any effect on the playing conditions nor will
  they be used in any part for umpire decisions," he added.

Without doubt, it will definitely help the umpires but the management didn't place those fancy toys for that purpose in the first place. But today, when it's being used in an ICC event, it looks like it may be serving its implicit purpose: helping an umpire in trouble.
Source.
Answer: Let me first tell you that it is not for fun.
It is a new technology which was first tested and used in the KFC Big Bash League in Australia. The main purpose of using it is, it will help the 3rd umpire to give the right decision for close calls when it comes to run out or stumping.
The LED light flashes only when the bail is completely dislodged from the stumps which means the 3rd umpire can get a clear view whether the bails are dislodged completely or not. On the basis of light flash he can make the decision so that the probability of making wrong decisions will reduce drastically.
Answer: This is the latest innovation in cricket which is invented by Bronte EcKermann. These high-tech stumps are called as Zings. The entire set-up during a match costs US$ 40,000. The main purpose of the LED stumps is to help the third umpire for decisions of stump outs and run outs.
From this article:

"The idea was to make it touch friendly. The light might not glow if someone tries to hit with a hammer but if the wicketkeeper touches the bail with ball in his gloves and even a feather touches, it would. It would make the decisions easier for the third umpire as to what exactly was impact when bail was dislodged from the stumps."

Other than this, it enhances the spectator experience during the match not only for the spectator at the match but also those watching in broadcast.

* Source: http://indianexpress.com/article/sports/cricket/zing-thing-40k-glowing-stumps-to-add-glitter-to-world-t20/


Which is the best place to search for a filed/issued patent?

Question: Which is the de facto and most recognizable patent DB in the world? Is it WIPO's database (the search engine and the interface seem limited) or Google Patents or maybe anything else? What is the difference between these and do they cover every country in Europe and also the States?
Answer: Personally, I find problems with Google Patents not finding all the relevant patents when I search. It is, however handy for finding an individual patent quickly. I prefer The Lens which I find more full featured, especially if you register (free). Ultimately, if you want detailed file histories, there is no substitute for individual country databases like the US Public Pair for the the US. I find Espacenet useful for European patents.
Comment: What about WIPO?
Comment: I've not used WIPO much. It looks good if a bit barebones from the UI standpoint. The professional patent librarians I've worked for generally used paid databases like TotalPatent or Micropatent. Hopefully, you'll get another answer which expands on mine.


Editing a label in "new individual" form

Question: I want to edit a field called "source" in the new Individual form. I want to change the name of the field. where can I change it?
Answer: You can use the word replacements feature, if you want to replace the word everywhere.
Or if you're just using that field for a different purpose, create a new custom field instead.
Comment: not everywhere, only in one place
Comment: and I have a problem in word replacements as well. It is not getting replaced in all places. Tried replacing "contributions" with "donations". the change is not getting reflected in CiviReport, while in other places it is changing.
Answer: Try some CSS:
<code>label[for=contact_source]
{
    /* ...definitions here... */
}
</code>
You can use the ::after to add arbitrary text, as per, e.g. https://css-tricks.com/almanac/selectors/a/after-and-before/
Comment: Do you mean javascript/jquery?
Comment: I was thinking ::before or ::after
Answer: You already had many answers how to. I will make a recommendation: create a custom field rather than manipulate a core CiviCRM field? It will be easier to maintain if fields change in updates of CiviCRM.
Comment: I think I'm with Erik on this one - a custom field is going to be a better strategy. Aside from the maintainability, another reason is that you have more control over the field if it's a custom field - e.g. you can set up a select for it, and it won't get auto-populated by various internal mechanisms.
Comment: I want to do the same thing that field  label "Source" does... It tracks the source of the contact from events.. Apart from events my organization has contacts from website, Stall, etc. I want to add values to the field like Website visitor, Stall visitor. But the Label "Source" is not self evident.
Comment: It is a recommendation :-) feel free to change the label with jQuery or css


Access Denied to Classic SharePoint Views

Question: I am a SCA and I "cleaned up" some SharePoint site permissions last week by removing membership groups from the Site Permissions list. This inadvertently caused everyone except Site Collection Admins to lose access to Classic Views. The users can still access pages and the content in Modern Views perfectly fine but if they try to access it in Classic View they get an access denied message. I created a test user account and assigned it Full Control permissions to replicate the problem on my end. Most of the site is still configured to utilize Class Views. Any suggestions how to fix this?
Comment: When you say they can still access pages, are they Modern pages or Classic pages?  If your users are getting access denied when accessing Classic pages, I would check to see if you removed access to the Master Page Gallery somehow. Specifically, I would check to see if you removed the "Style Resource Readers" permission group.  This is the group that allows users to view the Master Page Gallery.
Comment: Users can still access classic Wiki Pages. I don't use any Modern Pages on this site. Its only when they try to view a List/Library in Classic View that the Access Denied error appears. The Access Denied message even appears if they click "Return to classic SharePoint" from the Site Contents page.

I did remove it, but re-added it after I noticed the Access Denied message. I double checked and verified all users have read access to everything in the Master Page Gallery.
Answer: Finally determined what was causing the error. The Pages library did not have any permissions. I don't typically use this library but apparently permissions to it are necessary to view anything in Classic View.


imbalanced target dataset(multi class)

Question: I have a multi-class prediction problem
but the 300classes is imbalanced
should I make it balance all 300 class will predict the better result?
is there an easier method to do this job?
if I'm using the random-forest imbalance dataset is matter?
Answer: Nothing better if you could get more data and make classes (at least close to) balanced!
Choice of algorithm (I believe you using only RFC) entirely depends upon problem statement and as we all know, there is no free lunch in statistics, so you might've to try other algorithms (or just create a pipeline trying few more) as well.
Try over/under sampling and penalize your model by applying some custom matrix for miss classification, if required. Another point to keep note of is performance metric (avoid Accuracy paradox). Apart from deeper dive with F1, Recall & Precision; also try to look into [Kappa]1 or [ROC curves]2.
Based on the limited information (better idea would be to add a graph showing class imbalance) you've provided, this is the best I recommend. Hope it helps!

imbalanced target dataset(multi class)


Strengthening ceiling above the garage for additional storage

Question: I need some help. I am trying to figure out the best way to strengthen my garage ceiling to create storage space up above. The problem is the house was built in 1997 with a 2x4 W truss system. The span is 28'. I can see a break in the truss under one of the joint plates. Would sistering 2x4's in one 12' and two 8' sections all glued and screwed be enough to make it safe for storage? I am adding 3/4" plywood as the floor but also elevating the floor with 2x4 laid on their sides going perpendicular to the trusses. I am also adding an attic ladder for access.
Comment: Suppose the bottom cords of the trusses can be strengthened to support the load of stored items, will the walls support all the extra weight? This would be the weight of plywood decking, the extra 2x4s to elevate, plus the items stored? Someone qualified has to assure you of this. Are you going to gain enough storage volume to make this worth it? Is this a detached garage or integral to a house? Maybe a better solution would be a storage shed.
Comment: Thanks Jim. I am re thinking this as well. The 2 x 4 trusses are probably the very minimum to hold up the roof and ceiling. The yard is small so storage sheds could be problematic. Thank you for your feedback.
Answer: As a broad statement, this is a terrible idea. Why? Your truss system is designed specifically to hold up the roof and, to a lesser degree, tie your walls together.
2x4s spanning 28' with breaks are clearly not up to the task of holding up plywood and sleepers (parenthetically, not sure why sleepers seem like a good idea, but I digress), much less whatever stuff you (and future occupants) load up there. It simply isn't in the design.
What you'd need is something resembling a floor system... sturdy beams running across the 28' dimension with reasonably sturdy lumber running perpendicular to the trusses. (That beam at the front, by the way, is going to interfere with your garage door/opener.) Or some engineered joists running parallel to the trusses, which might or might not be able to simply bear on the top plate. On top of that, we need to ensure that the load on the joists/beams is being carried appropriately to the floor through posts, which then need to be carried adequately on a footing.
So, ask yourself: is all this worth the trouble? You'd lose either headroom in the garage or headroom in the "attic" because of a need for decently sturdy framing lumber. Cost of time and materials isn't trivial. You might need to revisit your garage door opener mechanism. Ensuring adequate bearing for joists or beams isn't going to be simple. You're probably digging new footings in your garage floor.
Storage sheds or offsite storage units start to look pretty good at this point.
So, capsule summary: this can be done. You need actual engineering expertise to do it appropriately. It'll cost a lot.
The alternative is to just chuck some plywood up there; undermine the structure of your garage; then call a contractor in 5 years to fix it all at great expense.
Disclaimer: I'm a professional carpenter, and I'd rather not have to charge people money to fix things like this.
Comment: Thank you for the feedback. I was going take the sleepers to the top of the walls strengthing the cord. The cord itself has a 2x4x20 and a 2x4x8 with a gusset plate at one of the v's. The problem is the trusses are probably the minimum in construction code which leaves little to add storage. When I bought the 3/4 ply wood and really to a look, I had to take pause. If the distance was shorter I would have just run 2x6's and not touched the trusses. Now I am facing something a little more expensive with either steel or as . I need to go back to the drawing board. Thank you for your expertise.


Heating issues in Apple II?

Question: My Apple II has been getting really hot in use, I've cleaned it, so I don't think dust is an issue. Is there something wrong with the hardware that could be affecting it? I've had Apple IIs overheat and break before, so I'm not sure if it was a factory issue or something that affected all Apple II computers.
Comment: Have you tried contacting Apple support? You can get their number off their website, they should be able to have someone help you. Just remember to tell them its the 1977 model.
Comment: @NightSkyCode even better...take it in to one of the "geniuses" at the Apple Genius Bar.  I'd pay $20 to see that.
Answer: The Apple ][ could overheat if it had a number of cards installed.  Especially if they were close together.  So, yes, it affected (almost) all of them.
This would affect the airflow within the case and heat would build up.
Back when I used Apples, I would try to have a blank I/O slot between each populated slot.  That would get the air flowing better.
I know certain cards got picky about which slot they were installed in, so your options may be limited.
Also, try not to block the slots at the back of the case with cables.  The slots are to enable cables from the cards to pass through the case and connect with peripherals.  However, bunging them up with cables can also impede airflow.
You don't say if you have any installed cards, or how many.  In my experience an Apple with a minimal number of cards would run forever without overheating.
Comment: An [aftermarket fan](http://thumbs1.picclick.com/d/l400/pict/222267980340_/Apple-ii-peripheral-Super-Fan-II.jpg) helps quite a bit.
Comment: I think that might be it. I have quite a few cards installed, I will try this.
Comment: Even with a lot of cards installed, how hot could it really get?  Unless you were over clocking it.  I've never run more than about 4 cards tops so maybe that's why I've never known any 8-bit computer to overheat.
Answer: A very common add-on for the Apple II was called the Kensington System Saver. This is a "Muffin fan" that hooked into the vent slots on the left side of the Apple II/II+/IIe, had a front-side master power switch, and 2-3 outlets on the back to power the computer, monitor, and printer.
This fan noise was a very characteristic sound for Apple II computers in schools, as you'd have a room of 20 Apple II's outfitted with System Savers.
Google image search: "Apple II" "System Saver" -- http://www.google.com/search?tbm=isch&q=%22Apple%20II%22%20%22System%20Saver%22
You can probably still find it on eBay.

For the Apple IIgs, it did not include a fan as a standard feature from Apple but it does include a place to clip one on to the power supply at the front corner, and a 2-pin plug on the motherboard for a fan.
Though the placement of the IIgs internal fan is weird, inside the case directly on the power supply, and I don't know if it actually pushed hot air out of the case or if it just blew the air in a circle inside the case, which would not have been very effective for cooling.
Kensington also made a System Saver IIgs which sat on top of the computer, under the monitor, with power switches across the front, and a fan to suck air up through the top of the IIgs and blow it out under the monitor. There was a rubber gasket around the edges to seal the System Saver IIgs to the top of the computer.
Google image search: "Apple IIgs" "System Saver" -- http://www.google.com/search?tbm=isch&q=%22Apple%20IIgs%22%20%22System%20Saver%22

If you are one of the lucky few to still own an Apple ///, you already know all about its overheating problems which were legendary for its time and which caused the untimely death of the system.
It ran extremely hot due to Steve Jobs' idiot insistence that fan noise sucks and air vents are unattractive. Socketed chips would slowly work themselves out of their chip-holders causing electrical failures. An official solution to this from Apple was to pick the machine up and drop it on the table to reseat the chips.
Reference: Wikipedia - Apple III https://en.wikipedia.org/wiki/Apple_III

Heating issues in Apple II?


How do I make metal bars in Dwarf Fortress?

Question: I am really at loss as to how to make metal bars.  It keeps asking me for refined coal, but I can't find any, and even if I did, I don't know what buildings I require for it.  I would really appreciate a total idiot's outline to making metal bars.
Answer: This is a complicated question, so I'm going to distill the basics and point you to Wiki entries for specifics.
Let's say for example you want to make an iron bar and have nothing but the required raw materials. First you need fuel (assuming you don't have easy access to magma).
Fuel
Fuel is either charcoal (from wood) or coke (from lignite or bituminous coal). Charcoal is made at a Wood Furnace b-e-w by a Wood Burner. This requires one wood. Production is one charcoal
Coke is made at a Smelter b-e-s by a Furnace Operator. Ingredients are one fuel and either a lignite or a bituminous coal. If lignite, the production is two fuel. If bit. coal, the production is three fuel.
So bit. coal is the fastest, most efficient way to make fuel if you have access to it. The trick is in order to start making fuel from bit. coal you need one unit of fuel, so you'll usually have to make a charcoal first.
Details here: https://dwarffortresswiki.org/index.php/DF2010:Fuel
Metal Bars
Now that you have fuel, you can convert your iron-bearing ore to iron bars. Metal bars are made at a Smelter by a Furnace Operator. Ingredients are one iron-bearing ore and one fuel. This produces one iron bar. (Iron ores are limonite, hematite, and magnetite.)
Iron is simple, but metal alloys like steel have a more complicated process. The Dwarf Fortress Wiki is your best source for specific info there.
List of various metals here: https://dwarffortresswiki.org/index.php/Metal
Comment: The Smelter doesn't have a "Make iron bars" task (like it does for brass, electrum, etc.). When you "Smelt limonite Ore" (or hematite/magnetite), you'll produce 4 iron bars.
Answer: You've got a smelter, which is the right workshop, so you're on the right track. You need fuel, which can be either coke (refined coal) or charcoal. Mined coal (lignite or bituminous coal) is not fuel. You also need a dwarf with 'furnace operator' enabled.
The trick is that you also need fuel for your smelter to make mined coal into coke. The way to bootstrap that process is with charcoal.
Cut some trees and build a wood furnace (b-e-w). Enable the 'wood burning' labor on a dwarf or two. Order a couple of charcoal made; you only need one to start your smelter, but a few more as a cushion is helpful, unless you're short on wood.
Once you have some charcoal stored, your smelter's menu will show all the ores you have available, as well as "Make coke from...". Bituminous coal is better than lignite because you get 3 coke per fuel used, while lignite gives 2 coke.
Once you have a few bars of coke, you can add metal smelting to the tasks; just be careful not to overdo it and run yourself out of coke. Planning your repeating tasks to avoid this isn't hard though. (Just remember that pig iron and steel require fuel as part of the process as well as powering it.)
If you don't have wood, you can trade for it or dig down until you find magma and build a magma smelter; those don't use fuel. (You'll probably find a cavern with underground wood before you find magma, so that'll work too.)
If you have lots of wood but no coal, just use charcoal for everything.
Comment: If you have lots of wood but no lignite/bituminous coal, dig down to a level that has it. I can't imagine that in 2010 there's an embark square without any coal.
Answer: Use DFHack Prospector to check your embark point before investing hours.
I've got a "Shallow Metals" "Deep Metals" site that has no metal ores.
Comment: Make sure you check the different biomes when selecting embark location.  It is possible it was one of the biomes in your embark area that had the metals, but you are digging in a biome that doesn't.


Recommendations for a BLDC motor and battery for a 28x20 propeller?

Question: I'm looking for a motor and battery set up that can last for over an hour and spin the propeller at 6000+ rpm. The propeller is a 28x20 single blade being connected to a second blade for a total of 56 inches. The weight of the whole propeller is 0.56lbs.
Answer: The first issue with your question is that you can't spin a 56" prop at 6000RPMs without it tearing itself apart. The tip speed of a 56" prop at 6000 RPMs is 1000mph, well over mach speeds. Practically speaking a 56" prop will probably be good up to about 3500 RPMs safely, with an absolute maximum of about 3700 RPMs (0.80 mach).
56x20 is massive, so you're going to need a significant motor. Based on the specs and what you're looking to accomplish it could vary some, but this motor is probably very close to what you're looking for: https://www.getfpv.com/lumenier-lu15-ii-80kv-professional-motor.html  The 40" props they've tested are only hitting about 3500 RPMs, and barely within the motor's wattage limits, so you will probably not quite be able to hit the maximum RPMs for the prop, but should be workable.


What is the history between Doug and Rachel?

Question: I guess I missed the back story on Doug and Rachel in House of Cards.  Why is he so involved with helping her?
Answer: Rachel is the call girl/prostitute who was with Peter Russo in the first episode.  If you haven't finished the season, then just keep watching.Spoilers below if you finished and missed it.

 She is a cat's paw in Francis Underwood's plan.  Doug was keeping Rachael around to be used against Peter Russo after they cleaned him up enough, for long enough, to run in the governors race.  The plan was to use her to create a scandal at the 11th hour in the governor's race.  The only way to keep governor's position for the party would be to have someone like the VP run at the last minute.  After the VP ran and won, the VP position would be vacant leaving room for Francis Underwood to be nominated.
Comment: Oh, wow!  Silly me thought Doug was really trying to help her.  And Peter didn't seem to recognize her when she came on to him so aggressively at the party.  I guess he was too drunk on the previous occasion to remember her.  Thanks for straightening me out!
Answer: First of all, Zoredache's answer is perfectly correct about his main motivation for caring about Rachel. She was at first a facilitator in bringing down Russo, to be taken care of and prepared for her further employment in this case, and later simply a confidant in the whole conspiracy, to be hidden from the world and cared for to not talk about it. But you weren't too far away in assuming some kind of personal angle in their relationship, even if that only really manifests itself in the 2nd season. So there is a much more complex relationship going on, even if I'd still consider Zoredache's answer as the more straight-forward solution to your actual question, especially when concentrating more on the 1st season alone.

During his control visits of her at the place where they're hiding her, he gets increasingly obsessed with her. By forcing that much control over Rachel he somehow made himself dependent on her, or rather on the feeling of Rachel depending on him, which also motivates his tries in isolating her from everybody else (although, this is also motivated by hiding her and the secrets she knows, but not entirely).
He urges her to cut ties with Lisa, the girl she randomly met and whom she becomes friends with and later shares her appartment and a loving relationship with. It seems this isn't entirely motivated simply by taking care of Rachel not to be found, since Lisa likely doesn't present much of a danger in this regard. And in fact he temporarily gives in and lets her live with Rachel, maybe realizing that she is very important to her and not of an actual danger for Francis's plot, but only until discovering their actual sexual relationship, which makes him fall back to his strict control over her.
It already shows that there is more to his relationship to her when he repeatedly has Rachel read to him, especially A Tale of Two Cities, the book his mother read to him when he was young. This also shows that his increasing obsession is not merely of a sexual nature, but much deeper (or at least weirder), as Doug admits himself during an AA meeting:

I work hard, I keep things simple, I know what my priorities are. There's this...this person, she's not even in my life except on the edges, making things blurrier. It doesn't tempt me to drink, it's more like she feels what's like when I was drinking, when I couldn't get enough. No matter how many drinks I had I wanted another. I...I don't want to be with her. I mean I...I do, but...more like she's my daughter...my mother...I don't know, this is fucked up...
I should cut her off, the way I did with booze.

So there is a much more complex angle to Doug and Rachel's relationship, or at least to his feelings for her (her attitude towards him is rather grounded in fear, it seems). Likewise it is IMHO not entirely clear what Doug is really upto when he drives away with her at the end in S02E13. Was he really just relocating her, or was he about to more finally "cut her off" to get away from his addiction (which is at least what Rachel assumed when ultimately attacking him in supposed self-defense)?
Comment: It's almost Hegelian. https://en.wikipedia.org/wiki/Master%E2%80%93slave_dialectic


Do first person shooters for console typically come with aiming help?

Question: This is a rumour I heard somewhere on the internet I have little trouble in buying: aiming with console controllers does not sound too easy, especially when you need to go for "twitch shots".
Is it, however, actually true?
Answer: Typically, yes. Using analog sticks to aim is not as precise as using a mouse. So in several games, if you get your aim close enough to a target, the game will help by giving it a nudge in the right direction. Or if you do get on target and the target moves, it may adjust for you. (Depending on the game of course).
Some games of course have a lot of aim assist, others have only a little, and some will allow you to disable it completely.
Answer: Different games offer different amounts of aim-assist, usually activated by holding down the "aim down the sights" button.  It ranges from full lock-on-and-track to just a gentle "nudge" towards center mass to none at all (or configurable).
In my experience, single-player games tend to have more aim-assist than multiplayer games, but not always.  The aim-assist greatly contributes to the unique feel of aiming in different games.
Answer: Some games even allow you to turn these features off; however, I've found that they don't always turn them off completely, they just tone them down.  The Halo games for example employ a target assist that will "pull" your aim towards an enemy when they drift close enough to your crosshairs; however, if this feature is turned off, they'll still pull your crosshairs a bit, but it isn't as obvious.
Most console shooters, especially ones with heavy single player modes, will also employ an auto-center feature.  As you move forward, if you do not actively look in other directions, it will automatically cause your sights to drift towards the center of the horizon.  Typically you can turn this off as well, but it varies from game to game.
Answer: I think that mosts of these games in single player mode it also give you some extra time for the enemies shoot at you because you are always a little bit slow for aiming and otherwise it would be imposible for beat any of them.


Tortoise SVN showing 'Access to '/!svn/me'' forbidden error.

Question: I recently want to commit a change to my WordPress plugin repo but it has been showing  'Access to '/!svn/me' forbidden' error whenever I wanted to commit any changes. Some articles have adviced me to check if my username and password are correct but it seems not to be the right solution because my login credentials are actually correct.
Please, has anyone faced this issue before or is there an alternative to TortoiseSVN that I can use?
Thank you!
Answer: login case sensitive. Do not write from Uppercase


Neutral-Phase reversal

Question: Could anybody suggest solution for a situation where, In a 3-phase, 4-wire system, phase and neutral are getting interchanged. How can I prevent this situation and what is it exactly called!?
Comment: Usually you can avoid that by proper training of the persons dealing with it. When it happens, I usually call it incompetence.
Comment: Please elaborate on the affected appliance (household, industrial). "Getting interchanged" and "How [to] prevent" sound like it's happening _right now_? Do you expect us to make those electricians stop what they're doing or do you just want why that is and how to correct the installation? I think this is an interesting situation, though I don't know what you expect the community to answer (answers could be quite broad).
Answer: You can use color codes if your installation uses it. However, I'd rather use a multimeter to be sure because -from my short experience- you're not sure if the technician did actually use color codes.
I've seen a phase conductor connected to a socket through an earth color coded conductor (Yellow/Green) because the technician ran out maybe of other colors :)
Comment: Any electrician who uses "earth-colored" wires for phase should be fried, or at least fired, but preferrably fried.
Answer: In EU we have black color for phase wires, blue for neutral and yellow/green for earth wire.
You can't swap the neutral with line, this can be a deadly mistake. You'd better hire somebody or stop doing this, please.
Comment: We also use brown for phase.
Answer: The old EU system was Black or brown for 3 phase lines.  To prevent wiring errors, the new standard is Brown, Black, Grey for L1,L2,L3 and in America, Red, Yellow, Blue colours are used. (RYB)
In applications where reverse rotating machines are hazardous to people or equipment, one will include a  three-phase monitor relay.

This protection consists of different RC passive filters that use phase shifting currents to activate a relay which in turn powers the 3 phase contactors when in the proper sequence or activates a light indicator if faulty.

Neutral-Phase reversal


is there a way to determine a distant galaxy's speed relative to the Hubble Flow by measuring time dilation effects between there and this galaxy?

Question: As I understand it there is a preferred frame of reference based on the velocity for the CMB and our galaxy is moving in relation to it (at about 600 km/s). I think this is how the Hubble Flow is defined. Given that there are no relativistic effects, and I really mean time dilation, between distant galaxies that are moving apart due only to Cosmological expansion, is there a way to determine a distant galaxy's speed relative to the Hubble Flow by measuring time dilation effects between there and here? If so using that and observed red-shifting, one could establish a more accurate measurement of the Hubble Constant.
Answer: No. Time dilation is expected and observed as a result of universal expansion (e.g. in the light curves of type Ia supernovae and the duration of gamma ray bursts, Blondin et al. 2008; Zhang et al. 2013). There is no way of distinguishing between a Doppler shift and cosmological redshift for an individual source.
Answer: There's no way to distinguish cosmological redshift from proper-motion redshift because there really is no difference. The universe isn't a smooth FLRW geometry with galaxies moving on it like test particles. It's more like a bunch of Schwarzschild-de Sitter patches stitched together. If you smooth out the bumps, you get an approximate FLRW geometry (increasingly accurate at larger scales), and you can define a scale factor and cosmological redshift formula and so on, but nature doesn't care about such approximations, it just integrates everything numerically. If you knew the exact shape of spacetime, you could compute the exact redshift by parallel transporting the four-velocity of the emitter to our location along the path of the light, then using the special relativistic formula. Computing the redshift as a factor for the emitter's peculiar velocity times a cosmological factor times a factor for our peculiar velocity is just an approximation.

is there a way to determine a distant galaxy’s speed relative to the Hubble Flow by measuring time dilation effects between there and this galaxy?


Educators, what resources have you built to better serve your students?

Question: What resources (Desmos, Geogebra, math3d, etc.) have you built to help your students better understand or visualize topics in mathematics?
Answer: Riemann Sum visualization
Fundamental Theorem of Calculus Explanation
Error bound on integral for increasing function
"Secant Circles" and "Tangent Circles"

Some students of mine worked out what would happen if you find the unique circle passing through three nearby points on the graph of a function, and then take a limit as those points get close to each other.  Similar idea to the tangent line development, but with circles.  They ended up needing Taylor series to get the exact equations for the "tangent circle"!

1-form visualizer

This visualizes the one form by looking at level sets of the covector in a small rectangle around each point.  You integrate the 1-form along a curve by just counting how many level sets you cross (taking into account the spacing $h$ between level sets).
Comment: Hah I like how we both have very distinctive styles with Desmos demos. These are great!
Comment: @Arthur I agree, but these were Calc  2 students who were "discovering" all of this on their own.
Comment: In my opinion, tangent circles make more sense in the more general context of plane curves (say, parametrized curves) rather than the particular case of the graphs of functions. The (reciprocal of the) radius of said circle is perhaps the most common definition of the curvature of a curve.
Answer: Here are some physics-related ones... many not quite as polished as they could be.

update:
webvpython / glowscript   (also supported on trinket.io)

EMwave - EMwave on trinket.io -  an interactive 3D animation that shows how the Faraday and Ampere-Maxwell laws propagate the electric and magnetic fields in a plane electromagnetic wave.

desmos

add Covectors (equipotenials) (draft version)
covectors map a vector (draft version)
161-robphy-Electric-VectorField-Superposition-v2 (draft)
Adding Equipotentials - point charges
Circular Wave Interference on a Screen (play the time variable)
spacetime diagrammer for relativity v.8e-2021 (time upward)

https://www.geogebra.org/u/robphy

Vector Fields, Divergence and Curl, and Flux and Circulation Integrals
Spherical Coordinates
Refraction-Snell Law
CircularLightClocks-VisualizingProperTimeInSpecialRelativity
Relativity-LightClock-MichelsonMorley-2018
Relativity on Rotated Graph Paper (robphy) - MAA2016
Virtual Torque Lab
Vernier Caliper
Comment: I love the spherical coordinates demo you have. I had a kind of crappy version that was not remotely as clean. Having the volume element represented is fantastic.
Comment: The special relativity Desmos demo is also great.
Answer: Desmos

Clickable Venn diagram with three sets and universe set
Unit circle
Secant lines motivating instantaneous rate of change
Tangent lines
Rolle's Theorem
Mean Value Theorem (for derivatives)
Slopes/concavity for building questions from
Inverse Function Theorem
Riemann sums with arbitrary (random) sample points
Riemann sums with left/midpoint/right sample points
Upper and lower Darboux sums
Method of exhaustion for area of a circle (part of a scaffolded assignment I give the students)
Riemann sums for areas between curves
Areas between curves
Trapezoidal rule
Simpson's rule
Arc length
Fourier series (warning: slow)

Geogebra

Volumes with equilateral triangle cross sections
Volumes with isosceles right triangle cross sections
Volumes with square cross sections
Volumes with semicircular cross sections
Volumes with circular cross sections
Volumes with washers
Volumes with washers
Volumes with cylindrical shells
Volumes formed by rotating around horizontal line
Volumes formed by rotating around vertical line
Cavalieri's principle

Colab

Numerical integration (trapezoidal/Simpson's rule)
Taylor approximations
Answer: Automatic-Algebra.org
I built this website for the purpose of timed self-quizzes on topics that should (mostly) be prerequisite, "automatic" knowledge prior to a number of basic college courses. Available quizzes include:

Times tables
Negative numbers
Order of operations
Sets of numbers
Special products
Finding intercepts
Special lines
Graphing lines
Decimal rounding
Decimal relations
Decimals to percent
Sampling distributions
Chained relations
Answer: I usually just use html/SVG combination and do it on a case by case basis. Examples include
https://www.math.kent.edu/~nazarov/switches/switchgame.html
(Linear system in $Z_2$)
https://www.math.kent.edu/~nazarov/Hillcipher/hill.html
(Linear cipher)
https://www.math.kent.edu/~nazarov/Buffon/buffon.html
(Buffon's needle)
https://www.math.kent.edu/~nazarov/T-intersection/tint.html
("real life" linear equations problem (ill-posed without prohibiting left turn))
https://www.math.kent.edu/~nazarov/turmach
(Turing machine emulation)
There is more stuff in that directory (mainly games made for Math. Club). It doesn't relate to the question directly, but you are welcome to take a look at it too just to see what can be done in two or three evenings with basic HTML skills (except Jeopardy: that one took a couple of weeks and was a work of several people). Some of these are not immediately obvious how to operate, but if you get interested in any of them, just let me know.
Answer: I've put together a number of online interactives in Javascript for College Algebra, Precalculus, Statistics, and Linear Algebra, available here: https://trkern.github.io/


Maven verify signatures of downloaded pom/jar files

Question: I was trying to find if there is SSL enabled central repository but there probably isn't. I noticed that there are signatures for every jar and pom file in maven central repository. So at least I'd like to check signatures of all maven downloaded files (pom/jar).
The example from http://repo1.maven.org/maven2/org/apache/ant/ant/1.8.2/:
ant-1.8.2.jar
ant-1.8.2.jar.asc
ant-1.8.2.jar.asc.md5
ant-1.8.2.jar.asc.sha1
ant-1.8.2.jar.md5
ant-1.8.2.jar.sha1
ant-1.8.2.pom
ant-1.8.2.pom.asc
ant-1.8.2.pom.asc.md5
ant-1.8.2.pom.asc.sha1
ant-1.8.2.pom.md5
ant-1.8.2.pom.sha1

I realize that I'll have to import public keys for every repository and I'm fine with that. I guess that public keys for maven central are here https://svn.apache.org/repos/asf/maven/project/KEYS.
There are PLENTY of tutorials on web on how to sign with maven. However I didn't find any information on how to force maven (2 or 3) to verify signatures of downloaded jar/pom files. Is it possible?
(Nexus Professional is not an option)
Thank you for help.
Comment: [MNG-2477](http://jira.codehaus.org/browse/MNG-2477) is the (currently open) issue to add this functionality to Maven.
Comment: Each artifact is signed with the individual uploader's key, so I don't know that KEYS will contain them. And when registering e.g. with the Sonatype OSS server, there isn't any phase by which the uploader's PGP key is put on file. That said, I also want an answer for this.
Comment: Are you using Artifactory or some like this? Is it an option?
Take a look at the plugins: http://www.jfrog.com/home/v_artifactorypro_features#addon-webstart
Answer: Now, that people seem to realize this is a real security problem (as described in this blog-post (the blog seems down, here is an archived version of the blog)), there is a plugin for verifying PGP signatures. You can verify the signatures for all dependencies of your project with the following command:
mvn org.simplify4u.plugins:pgpverify-maven-plugin:check

Of course, to be 100% sure the plugin is not malicious by itself, you would have to download and verify the source for the plugin from maven central, build it with maven, and execute it. (And this should also be done with all the dependencies and plugins that are needed for the build, recursively.)
Or you use Maven 3.2.3 or above (with a clean repository), which uses TLS for downloading all artefacts. Thus man-in-the-middle attacks are impossible and you get at least the artefacts as they are on maven central.
See also:

related Question and Answer
Sonatype's Blog to this topic
Answer: Could you write a bash shell script using GnuPG to verify each sig?
Something like:
for x in *.jar; do gpg --verify "${x}".asc; done
Obviously you would need the public keys for all the sigs before you started.
Comment: You would also need to fetch the signatures, as they are usually not in your repo.
Answer: Assuming you only want to download artifacts w/ valid checksums, one option would be to run the OSS version of Nexus and configure it to have a proxy of central.  Then configure your settings.xml to only load from your repo (mirror tag in settings.xml).  You can then configure nexus to only allow artifacts that have a valid checksum.
Comment: The *.asc files are PGP signatures.
Answer: SSL access to Central is now available for a token payment. From https://blog.sonatype.com/people/2012/10/now-available-ssl-connectivity-to-central/ :

We're making SSL connectivity to Central available to anyone that downloads open source components regardless of the repository manager.
...
In order to ensure the highest level of performance for those who count on SSL, we are securing the service with a token. You can get a token for your organization simply by providing a $10 donation that will be donated to open source causes.
Comment: This is/was correct but is now outdated. See Sonatype's announcement: http://blog.sonatype.com/2014/07/ssl_connectivity_for_central/


Changes in dna from dioxin poisoning

Question: A person sprayed with a dioxin, how long would it take for a dna change? Instant or over time? Would that person having children afterwards pass on any(if any) dna changes?
Answer: Studies on model organisms suggest effects begin quickly, within 6-8 hours of exposure. Rat studies suggest liver absorption of dioxin reaches a maximum from 8-24 hours, with Cytochrome P450 protein expression levels peaking afterwards. Another study uses a comet assay that measures DNA damage after six hours of dosing, and damage is tied to dose level.
Epigenetic changes to sperm and eggs are heritable, passed along to offspring. These result from histone deacetylation and methylation, which in turn change how DNA are packed and unpackaged for protein expression, and change expression itself.
A summary article on epigenetic dioxin (TCDD) toxicity suggests that there are specific effects on protein expression involved in embryonic development in model organisms, which result in birth defects and immune system damage.
In addition to controlled lab experiments on rats and mice, the United States of America and Monsanto conducted a massive, uncontrolled science experiment on humans, dropping dioxin in great quantities on millions of Vietnamese civilians during the Vietnam War.
Children of exposed victims suffered spinal bifida and other birth defects. US military exposed to dioxin in the course of deploying this chemical weapon also had their children suffer greater rates of similar birth defects.
Comment: Awsome,  thank you for the information... also does anyone know what immune changes with dixon poisoning?  Thank you in advance...

Changes in dna from dioxin poisoning


Why do we use $U$ for potential energy in classical mechanics?

Question: I am unaware if someone has asked this before, but I am studying classical mechanics and I don't know why do we use $U$ for potential energy. I have read that Rankine used it first, but I can't find any explanation for this.
Answer: It is possible that $U$ stands for "utility" (in mechanics), and it is due to Hamilton and not to Rankine. Possibly, Rankine wished to be consistent with Hamilton's notation, but, in any case, I suspect hat the modern use in mechanics has more to do with following Hamilton than with following Rankine, whose musings are very abstract and metaphysical, and are not even directed at mechanics. He does not even mention kinetic energy, for example.
Rankine's paper On the general law of the transformation of energy (1853) that introduces potential energy explicitly gives no explanation, "Let $U$ denote this potential energy" is all he wrote. It should be noted that the concept of potential energy is much older. It appears, in a rudimentary form, in Leibniz's writings under the name of "motive force", along with a prototype of mechanical conservation law, which Rankine spelled out explicitly two centuries later, see Leibniz and the Vis Viva Controversy by Iltis.
Lagrange used $V$ for potential energy in Mécanique analytique (1788-9), possibly from Latin vis, and $T$ for kinetic energy. Hamilton kept Lagrange's $T$, but, for whatever reason, switched from $V$ to $U$ in On a General Method in Dynamics (1834), which introduces what we now call Hamiltonian dynamics. Of course, neither of them called it "potential energy", but the letters occupy the familiar places in deriving equations of motion from a variational principle. Hamilton introduces

"A function $U$ of the masses and mutual distances of the several points of the system, of which the form depends on the laws of their mutual actions, by the equation $U=\sum. mm_{'}f(r)$, $r$ being the distance between any two points $m,m_{'}$, and the function $f(r)$ being such that the derivative or differential coefficient $f'(r)$ expresses the law of their repulsion, being negative in the case of attraction. The function which has been here called $U$ may be named the force-function of a system: it is of great utility in theoretical mechanics, into which it was introduced by Lagrange, and it furnishes the following elegant forms for the differential equations of motion... the second members of these equations being the partial differential coefficients of the first order of the function $U$".

The only word in this passage that suggests a reason for denoting the "force-function" $U$ is "utility".


Does it make sense to have long SSH Key with shorter Passphrase?

Question: If we encrypt our data with a longer SSH key which is protected by a shorter passphrase (with a decent entropy), then the limiting factor is entropy of the passphrase. So why do we use a longer key at all? We could simply encrypt the data with the passphrase.
Comment: The only SSH keys that are encrypted under a passphrase are the 'static' ones stored in files, and those are never used to encrypt anything, only to authenticate a host and optionally a client at the start of a session. You can encrypt data with a key derived from a passphrase, but not in SSH, where it would be significantly less secure and robust than the DHE or ECDHE key exchange that is currently used. Note the actual strength of RSA or (now deprecated in OpenSSH) DSA is much less than its size; i.e. 2048-bit RSA has strength of only about 112 bits. ECDSA needs only 2xstrength.
Answer: You're not modeling what information the attacker has.  The strength of the system only reduces to that of the passphrase if the attacker has a copy of the passphrase-encrypted private key.  If they don't, then the strength of the system is the strength of the private key.
You're not supposed to let your passphrase-encrypted private key file fall into adversarial hands.  The passphrase is providing a fallback in case that condition is violated.
Note that the passphrase is optional, and that there also exist non-passphrase mechanisms for protecting the private key. OpenSSH supports using smartcards instead of private key files, and there are apps for smartphone-based SSH authentication, where the private key is protected by the device's hardware.


On the existence of compactly supported functions whose its Fourier transform satisfies a given condition

Question: My question is concerned with the existence of compactly supported functions whose its Fourier transform satisfies a given condition: For $\gamma\ge 1$, one can prove that there is no compactly supported function $f$ satisfying $\left| {\hat f\left( t  \right)} \right| = O\left( {{e^{ - k{{\left| t \right|}^\gamma }}}} \right)$ as $|t|\to +\infty$?, for some $k>0$. Here $\hat f$ denotes the usual Fourier transform of $f$. Now I am interested in the case of $0<\gamma<1$. For $\gamma=1/2$, I can give an example of a such function, for example the standard bump function $\varphi \left( x \right) = \exp \left\{ { - \frac{1}{{1 - {x^2}}}} \right\}{\chi _{\left( { - 1,1} \right)}}\left( x \right)$ having $\left| {\hat \varphi\left( t \right)} \right| = O\left( {{e^{ - \sqrt {\left| t \right|} }}} \right)$ (see in http://en.wikipedia.org/wiki/Bump_function). My question is: Given $\gamma\in(0,1)$. Is there a compactly supported function $f$ such that $\left| {\hat f\left( t  \right)} \right| = O\left( {{e^{ - k{{\left| t \right|}^\gamma }}}} \right)$ as $|t|\to +\infty$?
Answer: As Denis Chaperon de Lauzières says, the precise answer to this question is given by the
Beurling-Malliavin theorems. They give a very precise characterization of weights $w\geq 1$
for which there exists a Fourier transform $f$ of a function with bounded support, such that
$f(x)w(x)$ is bounded.
The necessary condition is that
$$\int \frac{\log w(x)}{1+x^2}dx<\infty.$$
This is the famous "Logarithmic integral".
To make it also sufficient one needs some regularity. For example, if $\log w$ is uniformly
continuous then this is also sufficient. Another regularity condition is that $w$ is
itself a functon of exponential type with
$$\int\frac{\log^+|w(x)|}{1+x^2}dx<\infty.$$
References: Beurling-Malliavin, Acta math. 107 (1962) 291-309,
P. Koosis, Logarithmic Integral,
P. Koosis, Lecons sur les theoremes de Beurling-Malliavin.
Answer: The oldest reference I know which constructs compactly-supported functions with as good as possible decay of the Fourier transform at infinity is A. Ingham, "A note on Fourier transforms", J. London Math. Soc. s1–9 (1934), 29–32.
See also Th. 1.3.5 in Hörmander's "The analysis of linear partial differential operators I: distribution theory and Fourier analysis", Springer-Verlag, 2003.
(I think more refined questions are addressed by the "Beurling - Malliavin multiplier theorem").
Answer: Yes there is. What you need is the Paley-Wiener Theorem as in http://en.wikipedia.org/wiki/Paley–Wiener_theorem
Comment: In general, what you are asking about are functions in Gelfand-Shilov spaces. Perhaps there is something in the literature about these. I'd be extremely interested to know if it's true that if $\widehat{f} = O(e^{-k|\xi|^{\gamma}})$ for all $\gamma < 1$, then $\widehat{f}$ must be analytic on $\mathbb{R}$. But I don't know the answer.
Comment: So if $\widehat{f}(\xi) = O(e^{-k|\xi|^{\gamma}})$ with $\gamma \geq 1$ and $k > 0$, then this same method works. But for $\gamma < 1$ this says nothing.
Comment: Can you explain in more detail your anwser?
Comment: The Paley-Wiener theorem shows that if $\widehat{f}(\xi) = O(e^{-k|\xi|})$ for some positive $k$, then $f$ extends to a holomorphic function in a horizontal strip containing $\mathbb{R}$, and so vanishes on an open set if and only if $f$ is uniformly zero.


The "fun" tag and off-topic early questions

Question: the inevitable Joke and Quote questions are already up... how will they be dealt with?  Some have already pointed out that they are off-topic according to the FAQ... but similar questions helped to build the community on the StackOverflow site in the early days.  Will the community let it pass for now and lock the questions later?
Comment: Related: http://meta.photo.stackexchange.com/questions/27/when-is-off-topic-relevant-enough-to-be-acceptable
Answer: I will reiterate my answer from the Gaming beta re polls, meta, humor, etc.:

My theory on this is simple:
On StackOverflow, the early days allowed a certain amount of meta, poll and subjectivity in questions. As a result, in later months, after the system sorted itself out a bit better, newer users would point to those questions and then ask, "why was mine closed if programming jokes is still open?"
I would say the smart answer, if you don't want to be cleaning these up long-haul, is to nip them in the bud early, close them down, and get the rules straightened out clearly and succinctly.

We are asking for a world of pain to not shut those down quickly while in beta. That pain may not be today, tomorrow, next month or even in autumn, but it will come.
Answer: I am unable to see why quote and joke questions are not valid on photo.stackexchange.com.
If it is off topic according to the FAQ then it is time to change the FAQ.
If you are going to close those then you need to close so many other questions - what is your favorite photographer/blog,...
You should focus on good answers not stupid rules.
Comment: I have voted to close many discussion polls.  "This is not a discussion board, this is a place for questions that can be answered!" is a guiding principle for all SE sites, and included in all FAQs.  "[List of X questions] are not really what we want" (from [Meta](http://meta.stackexchange.com/questions/57226/should-we-have-a-list-of-x-close-reason), among many others on this topic).


Enable php5 on a single directory on an ISS server?

Question: On Apache server's I can create a .htaccess file with the following code.
<code>AddHandler application/x-httpd-php5 .php
</code>
Is there something similar that I can do for a windows server or does php5 need to be enabled site wide?
Answer: PHP can be disabled on an individual site via the Handler Mappings for a given site.  Information on setting up the handler mapping can be found here, but if it is already enabled on a site, you only have to disable it on the Handler Mapping settings.
You may also want to have a look at the PHP Manaager for IIS on Codeplex.


Ability for content authors to edit items without locking

Question: Hi we want to provide access to our content authors where they can start editing any item without the need to lock it. I am able to do this when I provide them administrator access. Is there a way we can do this, by not making them an administrator, but by a custom role?
Comment: Perhaps there is a misunderstanding of the purpose for locking. When one editor is currently working on the item, it would be a tragedy for another editor to overwrite their changes. Locking ensures that the appropriate person is in control of the item. Granting a user "Administrator" access would be another mistake because the user bypasses workflows and has the ability to wreak havoc. Perhaps you can share more details about what challenges you have faced when requiring the users to lock the items.
Comment: @michael-west, we are a small team. only one content author and one approver (who is also legal). So the overwrite option will never happen.  As you said, don't want to give them administrator access, hence looking for alternatives.
Comment: @NightMonger If there is only one content author and only one approver then there should not be any issue with locking of an item. I don't think that approver need to lock item for review purpose only. Even though if he locked the item while reviewing then as a best practice approver should release the item one he completes the review.
Answer: Like Micheal West said, If there is no locking functionality then When one editor is currently working on the item, it would be a tragedy for another editor to overwrite their changes. But in your case, there is a setting "RequireLockBeforeEditing" in the configuration which you can make it as false.
<code><setting name="RequireLockBeforeEditing" value="false" />
</code>
NOTE: This is not a Sitecore recommended practice.


Redirect problem for usernames with certain Unicode characters in them

Question: Trying to access this user's page leads to a "The page isn't redirecting properly" error for me using both Firefox and Chrome. I'm thinking there might be a problem with the handling of URLs for usernames that have certain Unicode characters in them.
Comment: This is not related to the reported issue itself, but in case you report other similar problems in the future, the characters in the English alphabet are also "Unicode characters."
Comment: @TsuyoshiIto You made a point, but I don't think cypher is entirely wrong. The problem may indeed be the program's handeling of Unicode characters. The English alphabet do not cause problems not because they are not Unicode characters but because they are ASCII characters as well, which the programs can handle. And I think cypher's intention may be that.
Comment: @TsuyoshiIto fair enough, I've replaced it with "certain Unicode characters."
Answer: The link above now works so it looks like it's been fixed, though I'm not sure on the details.