How much can we compress RSA public keys?

I am wondering to what degree we can define an RSA variant, with a security argument that it is as safe as regular RSA with a given modulus size $m$ (e.g. $m=2048$), in which the public key has a compact representation of $k \ll m$ bits.  We can fix the public exponent to our favorite customary value, e.g. $e=2^{16}+1$ or $e=3$, thus need to store only the public modulus $n$. We need not store the leftmost bit of $n$, which is always set by definition; nor the rightmost bit, which is always set since $n$ is odd. With a little effort, we could save (very) few more bits noticing $n$ has no small divisors, but that will still be $k \sim m$ bits.  We can do better by forcing the $\left\lfloor m/2-\log_2(m)-2\right\rfloor$ high bits of $n$ to some arbitrary constant such as $\left\lfloor\pi \cdot 2^{\left\lfloor m/2-log_2(m)-4\right\rfloor}\right\rfloor$. Observe that we can chose the smallest prime factor $p$ of $n$ just as we would do in regular RSA, then find the maximum integer interval $[q_0,q_1]$ such that any $q$ in that interval cause $n=p\cdot q$ to have the right high bits, then pick a random prime $q$ in that interval (most often there will be at least one, if not we try another $p$). Some of the security argument is that   generating an RSA key $(p,q')$ using a regular method, with random huge primes in some appropriate range and no other criteria beside the number of bits in $n'=p\cdot q'$, and $p<q$; then deciding the high bits of $n$ from those in $n'$; then finding $[q_0,q_1]$, generating $q$ as a random prime in that interval, and setting $n=p\cdot q$;   demonstrably gives the same distribution of $(p,q)$ as said regular generation method, hence is as secure; then we remark that the high bits of $n$ are random (with some distribution not too far from uniform), and public, thus fixing it can't much help an attack (I think this can be made rigorous).  This is now $k \sim m/2+\log_2(m)$ bits to express the public key. We can save a few more bits, each one at worse doubles the amount of work to generate the private key (we can repeat the generation process outlined above until we find a key with these bits equal to some public arbitrary constant; or equal to bits from a hash of the other bits if we want a tighter assurance that the scheme is not weakened).  Can we do better, and what's the practical limit?  Update: In , Marc Joye discuses this, and reaches $k \sim m/3$ (without claim of optimality). I'm worried that I do not see an argument that the manner in which $(p,q)$ are selected in Algorithm 3 does not weaken $n$ against a dedicated factoring algorithm.


I just purchased my first circular polarizer. I have read the thread  about when to use it, but I still have a question.     How to use it?   A friend told me to spin the polarizer until the sky turns blue. However, in addition to not making sense in many contexts, I don't really understand what this means.   The point is, I don't really know how to use this thing. What should I be looking for through my viewfinder when using this, so I was wondering if there was an easy explanation.(I am using a DSLR)  Thanks in advance.


So I know I can set user info details with this snippet:  _etmc.push(["setUserInfo", {     "email": "somebody@email.com",     "details": {         "foo": "bar"      } }]);   But how do I use these custom "details"? Specifically...   Does it populate in a data extension somewhere? I don't know what sets the data for the attributes and values 1-5 in IGO_PROFILES. Do they (or can they) relate to catalogue items? If so, how can I map these attributes/tags? Do I use a tilda (~) to separate multiple values like we do with content item tags? Can I use this in personalization rules and/or scenarios, and how if so?   I can't really find any documentation on the "details" property, but I've seen examples of it where it's set the "gender" of the user.  In my mind, I'm thinking that I can assign tags or keywords like "football" to catalogue items, and then if a user has a custom attribute like "interests" set to "football" in some profile setting, then the personalization studio engine could recommend or emphasize content with "football" to that user. Is this a thing? Thanks in advance!    Edit  Thanks! I'm new to this forum and couldn't find an existing question when I searched. However, the  did not answer all of my specifics (though it did answer some! So I appreciate the link), like how to separate multiple values. Is it comma, pipe, or tilda separated?  _etmc.push(["setUserInfo", {     "email": "somebody@email.com",     "details": {         "favorite_foods" : "eggs~toast~cheese",//Tilda separated??         "favorite_colors" : "red|yellow|blue",//Pipe separated??         "favorite_sports" : "football,lacrosse,cricket",//Comma separated??      } }]);   Also, @EazyE mentioned this in their answer, quoted from  (which I already found, but didn't understand):     Match a contact attribute to a tagged catalog field to increase the   subscriber's affinity for the value of that contact attribute. The   amount of increase is less than what results from a purchase but more   than the increase from a view.   Does that mean the key, like "foo" in my first example snippet, should match something in the "updateItem" call if I want to build that connection?  _etmc.push(["updateItem", {     "item_type": "content",     "item": "1234", // CONTENT_ID     "url": "https://example.com/1234/",     "available": "Y",     "foo": "bar"//This can be matched to users??     "favorite_foods": "eggs~pancakes~bacon"//Or this?? }]);


Let $m$ be the largest real root of the equation $\frac3{x-3} + \frac5{x-5}+\frac{17}{x-17}+\frac{19}{x-19} =x^2 - 11x -4$ find $m$

Let $m$ be the largest real root of the equation $$\frac3{x-3} + \frac5{x-5}+\frac{17}{x-17}+\frac{19}{x-19} =x^2 - 11x -4.$$ Find $m$.   do we literally add all the fractions or do we do something else  I have no clue how to solve this


I used these packages:  \documentclass{beamer} \usepackage{mathtext} \usepackage{amssymb,amsmath} \usepackage[T1,T2A]{fontenc} \usepackage{sidecap} \usepackage[cp1251]{inputenc} \usepackage[bulgarian,english]{babel} \usepackage{hyperref} \usepackage[font=small,labelfont=bf]{caption} \usepackage{mdframed} \usepackage{color} \setbeamerfont{caption}{size=\tiny} \usepackage{xcolor} \usepackage{framed} \usepackage{systeme} \usepackage{graphicx} %\usepackage{wrapfig} \usepackage{float} \usepackage{physics} \usepackage{appendix} \usepackage{mathtools} \usepackage{beamerthemesplit} \captionsetup[figure]{labelformat=empty}   Every time I run the Tex editor I get a message The requested package is unknown then details name="ragged2e" and after this window there is a window for intalling ragged2e.sty. I click install and this occurs again and again. How I get rid of it? Thanks!


I installed skype-ubuntu-precise_4.3.0.37-1_i386.deb from the Skype website, but when I start Skype, it is still 4.2, not 4.3. I've tried sudo apt-get remove skype, then installing it, but it didn't help.  Can someone help me?


Why is a union of n countable sets countable?

I have to show that  $$ \bigcup_{n=1}^{\infty}A_{n} := (a: \exists n \in \mathbb{N}: a \in A_{n}) $$  EDIT: So beneath this edit were just my thoughts. Above is the task. Is there any elementary way to prove that this Union of countable sets is countable? (besides counting like $\mathbb Q$)  As far as I understand countability, I have to show that the union is a bijection to $\mathbb{N}$.  $$ f: \bigcup_{n=1}^{\infty}A_{n} \to \mathbb{N} $$  Well, surjection is given by definition above, isn't it?  Now I only have to show injection. So if $f(a)=f(b)$ then $a=b$. How do I show that for the union?


Show that $\ln(\ln(n))$ is not rational for all integers $n\geq2$

This occurred to me while looking at my answer to      Show that   $\ln(\ln(n))$   is not rational   (and is undoubtedly transcendental)   for all integers   $n \ge 2$.   I am sure that this is true and have no idea how to prove it.  If it were, then $n = e^{e^{a/b}}$, and I don't see how to manipulate this to get a contradiction.  Gelfand-Schneider  doesn't seem to apply.  There may be a theorem that $e^{e^r}$ is transcendental for rational $r$, but I don't know it.  If you can do this, then do the $k$-fold iterated log, $\ln_k$, to show that $\ln_k(n)$ is irrational (and, again, undoubtedly transcendental) for all $n$ large enough so that $\ln_k(n)$ is real.


Can I use an Update cursor with a versioned feature class which has attachments in ArcObjects .NET

I have a problem with my code (C# ArcObjects 10.1). We are trying to update and insert 10 - 15 rows at a time into a feature class hosted in ArcSDE 10.1 on SQL Server 2008 R2.  We have a feature class which is versioned with move edits to base and also has attachments which are photos.  I did some proof of concept code a few months back and thought I had everything working - I had tested inserting and updating a versioned feature class and inserting attachments associated with a particular feature. Looking back, I don't think I tried these at the same time - the feature class I tested inserting attachments may not have been versioned.   The issue I am facing is that my code was working fine and inserting and updating features, as soon as I added the attachment table - it stopped working and I get this error :  Objects in this class cannot be updated outside an edit session     [SDE_CSO.DBO.DefinitiveList_COPY]   at this line :  IFeatureCursor cursor = featureClass.Update(queryFilter, true);   I am starting an edit session and edit operation before attempting this :   muWorkspaceEdit = (IMultiuserWorkspaceEdit)featureWorkspace; workspaceEdit = (IWorkspaceEdit)featureWorkspace;   muWorkspaceEdit.StartMultiuserEditing(esriMultiuserEditSessionMode.esriMESMVersioned); workspaceEdit.StartEditing(true); workspaceEdit.StartEditOperation();   I did some googleing around and found a few old posts on the ESRI forums about a similar using using ArcPy and ArcObjects which seemed to suggest that using an Update cursor will not work with a table which is involved in a relationship.   So my question is.... is this possible with an update cursor - if so how? If not can someone offer an alternative solution?


Does a fighter's Action Surge trigger Extra Attack?

Context  A player in my game will play a fighter with a greatsword. At 5th level he has Extra Attack and the option to use Action Surge. PHB p.72 states:     Action Surge. Starting at 2nd level, you can push yourself beyond your normal limits for a moment. On your turn, you can take one   additional action on top of your regular action and a possible bonus   action.      Once you use this feature, you must finish a short or long rest before   you can use it again. Starting at 17th level, you can use it twice   before a rest, but only once on the same turn.        Extra Attack. Beginning at 5th level, you can attack twice, instead of once,   whenever you take the Attack action on your turn.       The number of attacks increases to three when you reach 11th level in   this class and to four when you reach 20th level in this class.   Confusion  The questions and answers that I find on here deal with multi-classing or Two Weapon fighting specifically, which don't really give a clear yes or no on my question.  The way I read these two features is that when a fighter takes an Attack action, he gets the Extra Attack. After using Action Surge he gets the opportunity to take another Attack action, and with that another Extra Attack. This results in four attacks with the greatsword in one turn, which sounds amazing but also rather powerful. Is this correct, or am I missing something?


Hotspot and Internet access together -- why not?

If I go Settings → Network → Wireless and select Use as Hotspot..., I get the following message:  If you have a connection to the Internet other than wireless, you can use it to share your internet connection with others. Switching on the wireless hotspot will disconnect you from ABC. It is not possible to access the internet through your wireless while the hotspot is active.  What are the technical reasons why I can't set up an Hotspot and be connected to the Internet at the same time?


When does a finite ring become a finite field?

I'm relatively new to ring theory so this is probably a simple question.  Its easy to see that a finite ring that is commutative and has no-zero divisors (i.e. an integral domain) must have multiplicative inverses.  I am wondering if we can rearrange these properties and always get implication or produce finite rings with only 2 of the above properties.  Explicitly my questions are:  1) Does a finite ring that is commutative with multiplicative inverses always have no-zero divisors? (EDIT: this one is pretty easy too, let $xy=0$ and assume $x\neq 0$. then $x^{-1}xy=x^{-1}0$. Hence, $y=0$ as desired.)  2) Is a finite ring that has multiplicative inverses and no zero divisors always commutative?  If these are actually simple exercises, I'd just like a hint to get started with the proof or any counterexamples.  Thanks :)


How to find the last digit of $3^{1000}$?

I'm thinking of modulo, but really don't know how to start? A hint would be sufficient.     Thanks, Chan


I want to fit the artboard to selected art (two text boxes) - the text boxes are larger than the text inside them - how do I fit (shrink) them to wrap tightly around my text?  Illustrator version - CS5


Better or faster way to convert InputStream to Json in servlet

In the servlet, I want to make a call to another system using HttpClient to get a JSON response, and here, I don't want to do any manipulation. Just need to give the response to Ajax whatever JSON response I got from other systems. Here I am just converting InputStream to string and give to Ajax. String text = new BufferedReader(               new InputStreamReader(res.getBody(), StandardCharsets.UTF_8))                 .lines()                 .collect(Collectors.joining("\n"));             response.setContentType(JSON_CONTENT_TYPE);             System.out.println("Resonse-->"+text);             final PrintWriter out = response.getWriter();             out.print(text);             out.flush();  Above code simply converted to string and returned as json as below {     "status": "success",     "data": {         "expiresIn": 1558,         "userId": "xxx",         "countryCode": "US",         "sessionKey": "asd"     } }  But would want to know if this is correct or any other better or faster way to convert InputStream to JSON object to Ajax.


Saw this notification in my list, went to comment, and was informed I didn't yet have enough rep.     Is it possible to lose reputation and therefore lose privileges on stackoverflow? (I don't remember ever hitting 50 in the first place, and my rep earned prior to that doesn't add up to 50 anyhow.)  I can't think of another good explanation other than a coding error or notification code that wasn't updated when privilege levels were changed. (I haven't been around here long enough to know -- though that should be self evident, heh.)


If nothing can travel faster than speed of light then how the Universe is only 13.7 billion years old?

The light would take 93 billion years to reach the edge of universe but nothing can travel faster than the speed of light not even the big bang?


[removed, apparently its duplicated question..]


How to declare some aliases dynamically in zsh?

I would like to declare a few shortcut commands to switch between my various coding projects, so I have come up with the following script.  projects=$(ls -d ~/Workspace/*/) prefix="/Users/myuser/Workspace/" for f in $projects do         temp=${f#$prefix}         temp=${temp/%\//}         c="alias $temp='cd $f'"         echo $c         eval $c done   I put that in a file called .workspace-shotcuts.sh in my homefolder, then I chmod +X .workspace-shotcuts.sh it.  when I run it, using ./.workspace-shotcuts.sh I get   alias project1='cd /Users/myuser/Workspace/project1/' alias project2='cd /Users/myuser/Workspace/project2/'   in the console. But the aliases are not declare (zsh: command not found: project1).  Also at the end of my .zshrc file I have added /bin/sh .workspace-shotcuts.sh, which gives the same output, but still no aliases.  Any body can tell me what I am missing? I would like to point out that I am not a great *nix user, so you might have to ELI5 some things to me.  EDIT:  I was suggested to use source instead, which I have done, but here is the error messages I get:  (eval):2: permission denied: /Users/myuser/Workspace/project1/ (eval):3: permission denied: /Users/myuser/Workspace/project2/     (eval):4: permission denied: /Users/myuser/Workspace/project3/ (eval):5: permission denied: /Users/myuser/Workspace/project4/ (eval):6: permission denied: /Users/myuser/Workspace/project5/ (eval):7: permission denied: /Users/myuser/Workspace/project6/ (eval):8: permission denied: /Users/myuser/Workspace/project7/ (eval):9: no such file or directory: /Users/myuser/Workspace/project1=cd /Users/myuser/Workspace/project1/\n/Users/myuser/Workspace/project2/\n/Users/myuser/Workspace/project3/\n/Users/myuser/Workspace/project4/\n/Users/myuser/Workspace/project5/\n/Users/myuser/Workspace/project6/\n/Users/myuser/Workspace/project7/   What is happening? Is there some special permission I need to give my script?


Am I allowed to release a fan-made version of a Trading Card Game on a fansite?

Consider a Trading Card Game that is currently available for play in digital format only, the game in question would be HEX: Shards of Fate, but this question is intended as a general question about all Trading Card Games.  Now my idea is to create an AI player for that game and see how good it performs. For this I'll need to build a client that is capable of playing the game and initially I want to test it myself and distribute it to a few friends so they can play around with it.  I am myself unsure of whether the EULA specific to this game are of any importance, as I believe all games will try to protect their games to the fullest extent as possible. However we also know that there are fansites out there which are allowed (are they legally allowed?) to display the cards of the game (including artwork) as long as they have a clear reference to the game which it is about and they do not attempt to make any money out of the cards themselves. I do believe that premium services on a fansite itself are legal.  Ultimately I want to create a fansite where:   There is an obvious reference that the cards, etc. belong to the company that created the game. You can as player play versus an AI, using a game interface that is similar to the one that is in the actual digital version. It most likely won't be an exact 1:1 copy and some substitute interface will be used that doesn't look as nice. Playing versus the AI is not promoted as an actual game, it is just a site where you can test your skill as player, and as creator I can test the effectiveness of the AI. All cards are freely available to any player, I most surely do not intend to monetize that part. There is possibly a premium service that offers benefits, possibly more detailed statistics or more AI matches, more options, etc.   So I've got the following questions about this:   Is the limited distribution amongst myself and friends legal? Is this fansite legal without the premium service? Is the premium service legal? Would selling booster packs (where you can obtain the cards) and having the player start with a minimal collection actually be illegal?


Is it possible to have change tracking ONLY on a replication server, not original?

I am working on a system where we are pulling records from a replication server and need to know when changes have occurred.  We would like to not have to touch the original server and only read from it, including not being allowed to enable change tracking.  Can this be done?  If need be, we will simply pull all Record IDs every night and compare the two but it's certainly not the ideal solution considering we have tens of million of records.  I have seen this question:      The answer to it seems to be suggesting that the way to do this is to enable change tracking on the original server that is then replicated, which in my case is not an option.


What is the source of the Infection in "The Walking Dead"?

What was the cause of the virus that turned dead people into zombies? For example, was it after a nuclear blast or explosion? Was the virus in food or water? Or did the virus surface because of a post apocalyptic occurrence?


HAC standard error or missing ARMA terms

In the context of regressions, it seems a convention that the HAC estimator should be applied when the residual is serially correlated. But isn't the presence of residual autocorrelations an indication that the model misses lagged dependent variables (or MA terms for that matter)?  For example, suppose one is investigating the impact of variable $x_t$ on variable $y_t$ in a time series context. A simple model is $y_t = a + b x_t + \varepsilon_t$. It is often the case that the resulting error term $\varepsilon_t$ is serially correlated. One response to this problem could be just applying the HAC estimator to correct the standard errors of the parameter estimates, while arguing that the parameter estimates are still consistent in the presence of residual serial correlation.   However, in this case, one could often add lags of $y_t$ to the model to remove the autocorrelations in the residuals, e.g. $y_t = a + b x_t + c y_{t-1} + \varepsilon_t$. Since the lag $y_{t-1}$ could be correlated with the regressor $x_t$, either by economic reasoning ($x_t$ is often serially correlated) or by sample correlation between the lag $y_{t-1}$ and the regressor $x_t$, it would be simply wrong to ignore the lag $y_{t-1}$ while just correcting the standard errors by HAC.  This makes me wonder why one would ever use HAC estimator in regressions? At most, use the White estimator to correct for heteroskedasticidy if it is present. Otherwise, whenever there is residual autocorrelation, investigate adding AR or MA terms but never simply use HAC estimator.


Enable searching with deleted:1 for 10k users

I just tried to find a recent answer I wrote (or comment, can't remember), but I couldn't. I assume the question was deleted. Can the deleted:1  be enabled to 10k users? We can see deleted posts, so why can't we at least target them in search?  I understand that allowing us to search for all deleted posts from someone else can be problematic. Quoting Yannis Rizos' comments:     if deleted:1 becomes available to 10K+ users there should be a restriction on coupling it with a user id (except perhaps when you are searching for your own deleted posts).   So, user:<userID> deleted:1 would be disallowed (except for your own user id), but something like [tag] deleted:1 would be allowed.


Is there a non-vulgar version of "pulled it out of their ass"?

Is there a non-vulgar version of “pulled it out of their ass” ? It's a useful phrase, but not one to be used in professional environments.   For example:     There is no way John’s projections for next year’s sales are accurate. He ____.


Explain why perpendicular lines have negative reciprocal slopes

I am not sure how to explain this. I just know they have negative reciprocals because one one line will have a positive slope while the other negative.


How do you turn hostile mobs against each other?

I have been thinking of how to make a "mob war" map using the theory that owned projectiles can turn mobs against each other, along with shulkers being able to act as defense turrets for those on the same team. I have tried the {ownerName} tag on projectiles to turn non-shulker hostiles against each other, but to no avail. They appear to have no effect. Is this feature manipulable without plugins? If so, how?


In what state is a person affected by Hypnotic Pattern? Can they make saving throws?

I'm reading the Hypnotic Pattern description and it says "Charmed, Incapacitated, Speed (0)" and "Snaps out of it, if being shaken or takes damage."  Then I read the various states you can be under:     Charmed: can't attack the caster   Incapacitated: can't take actions or reactions - is a save an action/reaction?   Immobilized (Speed 0): Somewhere between Paralyzed, Restrained and Stunned — which all say you auto fail Strength and Dexterity saves and people have advantage on attacking you.   If I were to Fireball an individual (or group) under the influence of Hypnotic Pattern, would they get a Dexterity save to duck out of harm's way?


Alternative proof for differentiability of inverse function?

Problem Let $f$ be a continuous one-one function defined on an interval and suppose that $f$ is differentiable at $f^{-1}(b)$ with the derivative $f'(f^{-1}(x)) \neq 0$. Prove that $f^{-1}(x)$ is also differentiable at $b$.   I read the proof in Spivak Calculus book, but it's quite confusing to me. Then I looked up online, and I saw exact the same proof everywhere. So I wonder is there an alternative proof to this problem that I'm not aware of?   Here is the proof from Spivak book   Theorem 5 (Calculus by Spivak 4th edition, page 237-238) Proof. Let $b = f(a)$. Then     $$\displaystyle\lim_{h\to 0} \dfrac{f^{-1}(b + h) - f^{-1}(b)}{h} = \displaystyle\lim_{h\to 0}   \dfrac{f^{-1}(b + h) - a}{h}$$     Now every number $b + h$ in the domain of $f^{-1}$ can be written in the form     $$b + h = f(a + k)$$     for a unique $k$. Then     $$\displaystyle\lim_{h\to 0} \dfrac{f^{-1}(b + h) - a}{h}   = \displaystyle\lim_{h\to 0}\dfrac{f^{-1}(f(a + k)) - a}{f(a + k) - b}   = \displaystyle\lim_{h\to 0} \dfrac{k}{f(a + k) - f(a)}$$     We have     $$f^{-1}(b + h) = a + k \Leftrightarrow k = f^{-1}(b + h) - f^{-1}(b)$$     Since $f$ is continuous and one-one, $f^{-1}$ is also continuous at $b$. This means that $k$ approaches $0$ as $h$ approaches $0$. Since     $$\displaystyle\lim_{k\to 0} \dfrac{f(a + k) - f(a)}{k} = f'(a) = f'(f^{-1}(b)) \neq 0$$     this implies that     $$(f^{-1})'(b) = \dfrac{1}{f'(f^{-1}(b))}$$


Is auditing graduate physics courses (officially or unoffically) a viable way to eventually get into a PhD program?

I am considering a possibly risky route into graduate school. Namely, auditing classes at the university I would like to attend and then reapplying after a semester or two. This way I can demonstrate my abilities directly.


How do I set access permissions per field?

What I need to do  I have some user account fields that should be administrator-only (read/write/edit).  For example, the IP address used to register.  So, I want to restrict access to administrators.  Current state of field permissions in Drupal 8 (as of Feb 19, 2016)   In Drupal 7, I used the  module.  However,  There is a , but this has been going on for seven years and is marked as "postponed."


Why should be accept this ${\displaystyle {n \choose k}}=0 $ for $k> n$?

I'm confused how  ${\displaystyle {n \choose k}}=0 $  for $k> n$ however the  ratio :${\displaystyle\frac{n!}{(n-k)!k!}}$ is not defined for $k>n$ ?  My question here is: Why should be accept this $${\displaystyle {n \choose k}}=\frac{n!}{(n-k)!k!}=0 ,  for , k> n$$ ?  Note: I don't accept this if it were by convention because it's not defined !!!!  Thank you for any help


What differentiates the Radchaai warship classes?

What is difference between the Radchaai warship classes in the Imperial Radch series?  As far as I am able to tell, Justice-class vessels are troop carriers, and Sword-class vessels seem to be specialized for space superiority. What about Mercies?


Is it true that a boundary of a simply connected and bounded set is connected in $\mathbb{C}$?

I was thinking about Julia sets when I asked myself whether is it true that Is it true that a boundary of a simply connected and bounded set is connected  $\mathbb{C}$? Is it a well known fact? I found a proof here:  but it's not convincing since it relies on facts that are not even proved nor mentioned... Such that a path must cross the boundary in order to exit a set, the rather intuitive definition of "lying around" and the behavior of homotopy.


Want to do mathematical physics - if first choice dept not a good fit, can I switch?

I am writing on behalf of someone else.  But the question will be easier to pose if I put myself in his shoes and speak in the first person.  I will soon graduate with a Bachelor's in economics and mathematics in a Third World country.  I have, however, also studied physics. I actually have more physics than mathematics courses on my transcript.  I want to study for a PhD in mathematical physics in the U.S. I would need support (e.g. TAship).  Where I live, subject GREs are only offered once a year, and one is not permitted to take two different ones on the same day.  It is too far and expensive for me to travel to another country to take a second subject GRE.  Suppose, for the purpose of this question:   I decide to take the Physics GRE, and apply to physics departments I get admission to a physics department, and a TAship I take a combination of both math and physics courses and do well After several semesters I realize I'd rather that my home department were math, instead of physics      How hard would it be to apply to switch over to a math department (either in the same university, or a different one), assuming I had taken sufficient math courses, and done very well in them?   Note: The  is somewhat helpful, but I would like to see a specific focus on the math/physics interface; also, please consider the specific option of pausing at completion of a masters, with a switch of department at that point.


In the films, I only saw organic life forms become Jedi or Sith. Were there ever any droids who could use the Force? Or is that impossible because of the ?


Can an AES-256 key be generated for a large number of cribs?

I have a question in regards to Ransomware type viruses. I know that a number of these viruses use the AES-256 algorithm to encrypt user's files using a randomly generated key. I work in IT support and I had one client the other week who had lost a large number of important files this way but one thing which struck me was that we were able to recover a large number of files via DropBox - about 500 files (~2gb worth of data) and because the virus only changed the extension it was clear which unencrypted file corresponded to which encrypted file.  What I was wondering is; with a large dataset like this where you have both the encrypted and unencrypted data would it be possible to calculate the encryption key for an AES-256 algorithm in a reasonable time? I don't know how these algorithms work but presumably you would have so much data available to compare that it should at least make the task considerably easier should it not?  I'm not intending to rid the world of ransomware but it just interested me!  Cheers,  Olly


Why is it that Frisian is considered the closest related language to English?

It is commonly asked "What is the closest language to English?" and the equally common answer is         Except that there is rarely a reason given for this connection; the most that is given are baldly stated 'facts' (e.g. "English and Dutch are in the same 'Low German' group")  Can anyone give any substantive reasons? For example, an comparative overlap of vocabulary, a distance metric of phonology, privately shared syntactic rules among all the rules in West German languages.


I would like to know what do I have to do if I want to convert the my Tex document into an image.  I'm new to Latex World, sorry if it is a dumb question for somebody


I am Windows user for quite a long time and wanted to try Ubuntu. With no experience of using any other OS than Windows, I started searching about Linux and found that Ubuntu is by far the most popular distro. Hence, my next search was how to install it alongside my Windows 10. After following step by step guide, I managed to install Ubuntu 20.04 using USB bootable disk on my Lenovo Legion Y520 laptop.   It is very capable laptop at least for Ubuntu, having Intel Core i5-7300hq, 16GB RAM, Nvidia GTX 1050 4GB, 1TB HDD.  I later installed ADATA 256GB NVME M.2 SSD and installed Windows on it. The first problem I face while installing Ubuntu was that I didn't had an option to select my NVME SSD, the only option available was my HDD. Since I didn't had other option I went ahead with HDD installation.   The Installation went smooth though very slow, at least as compared to a Windows 10 installation. But I gave it a benefit of doubt since my Windows 10 is installed on NVME and this Ubuntu installation is done on mechanical HDD. I then changed my regional settings to US and it asked me to restart the PC.   From here onwards I started hating Ubuntu simply because it took around 5 minutes to restart. I thought that may be it is first time that is why it is taking time and therefore I decided to shutdown the PC so that I will power ON it again to see the difference.   Ubuntu refuse to power off and stuck at stopping disk. The had to hold power button to switch that off and immediately came here to ask you guys if I have done anything wrong which is causing Ubuntu to behave unusually.


I have this tex: \(\mu_{A}\left(x\right)\in \[0,1  \right\]\)  The issue here is that [ and ] are not showing around 0,1, why is that?  Thanks.


How would I go about proving P>Q from the premise (notP v Q)?

A similar question had already been asked, but the solution involves steps I am unfamiliar with. in class, we have only been exposed to intro and elim rules, as well as contradiction rules.  Here is the original question:  I am not familiar with "DS" as a method


How can I know how long `dd` cloning will take?

I have to dd a couple of 1TB hard drives. They are taking several hours to clone and I was wondering if there was any way possible of knowing how fast they are going, how much they have done and how long will they take to copy the rest.  All I can see is the terminal with the command running. When I run ps -e at least I know that dd is working from the CPU usage shown, but I have no way of knowing how much it has done or how long it will take to finish.  Kind of makes me crazy.


I am trying to understand the  for simulating random processes and have managed to completely confuse myself.  Consider a Poisson process whose conditional intensity is  $$\lambda(t) = \alpha e^{-t}$$   starting at time $t=0$ for some parameter $\alpha>0$.  To apply the inverse transform method I need to start with the cdf (called $F$ in the notes that I have linked to) and then compute its inverse. What is the relevant cdf $F$ for this process?  My overall goal is to be able to simulate the arrival times from this process.


Some problems about isomorphism of groups

1) Let $G=\mathrm{Aut}(\mathbb {Z}_4\times\mathbb {Z}_2)$. Show that $|G|\leq8$ and then $G \cong D_4$.      2) Show that $\mathrm{Aut}(S_3\times \mathbb {Z}_3) \cong S_3\times\mathbb {Z}_2$.   At the moment I was able to do the first part of the first problem. I noticed that $\mathbb {Z}_4\times\mathbb {Z}_2$ has two generators, $(1,0),(0,1)$, so an automorphism $ϕ$ will be fixed if I choose their images. Both $(1,0)$ and $(0,1)$ have order $4$, and I can see that there are only $4$ elements of order $4$, so I only have $4$ elements that can be their images. Because of this facts I have $4$ possibilities for $ϕ((1,0))$, but only $2$ for $ϕ((0,1))$, because it can't be an element of order $4$ that is in the subgroup generated by $ϕ((1,0))$. So $|G|=8$. Is it correct?


What is the reason for the /private directory structure located at the root of an OSX system volume?  Why are /etc, /tmp, and /var symlinks to subdirectories of /private?  NOTE While writing my question, I discovered  which seems to address this issue.  I'm going to post my question anyway because it contains the terms that I searched for.  The other question/answer doesn't, prompting me to start writing this question in the first place.


Finding when and why ancestor was in Bodmin Gaol ca 1835-1839?

I'm looking for inmate records for Bodmin Gaol jail in the UK circa 1835-1839. My 4th great-grandfather Phillip Stephen Rule (born 1777) was an inmate there based on records I have found on ancestry.com, but all I can find is his release year of 1839. I cannot find when he was imprisoned or what he was in there for to begin with.


Kubuntu fresh Installation and breeze icons are missing in GNome application style, so dolphin looks ugly

I have a fresh kubuntu installation and breeze themes icons are missing.    I already have cleared my cache by moving .kde and .cache. I have already tried to change theme but no success.  My main concern is that dolphin looks very different then it should. See dolphin screen-shot.    Can anyone help me with this?


How do solve $\int\frac{2\sin(x)+3\cos(x)}{3\sin(x)+2\cos(x)}dx$?

How do I solve this integral? Should I use some kind of an integral substitution?


'Recently active' and 'Newest' sort don't work for the new navigation layout

Compare:    With    The Newest of the new questions at that point is from 2013:    How do the sort methods actually work? Is this what's intended or are they broken?


Can a Rogue apply sneak attack on a reaction/opportunity attack?

The 5e PHB says a Rogue can only apply Sneak Attack (given the conditions are met) once per turn. Does this differentiate between the Rogue's turn and the entire combat round? If the Rogue gets to make an opportunity attack as a reaction, and the conditions are met, can he apply Sneak Attack on that? Is that considered a separate turn? Does using it on either one prevent its use on the other in a single round of combat?


I know that this has been asked before, but the answers that others have received did not help me much.  When creating objects through Python, using bpy.ops.mesh.primitive_cube_add() there is an exponential slowdown when looping the creation of objects.  My script that I am writing takes an image and creates a grid of cubes based on every pixel.  It also assigns a material to each cube based on each pixel's color.  When running it on a 32x32 image, it is very fast (about 1 second).  When running it on a 100x100 image, the script gets slower and slower as it runs.  I also have learned that using a low-level method to create my cubes I won't experience the slowdown.  I changed my code to a low-level method, and the speeds are much faster, but I still experience the slowdown.    copy = ob.copy() copy.data = ob.data.copy() copy.data.materials.append(material) copy.location.x = x - 1 copy.location.y = y - 1 copy.location.z = 1 bpy.context.scene.objects.link(copy)   Here is my current code for creating cubes.  My full addon can be accessed here:   Is there a faster/better way of doing this?  Because I would really like to be able to create 100,000+ cubes without waiting hours.  Thanks.


How do I reuse a map in a different game?

I was playing a very nice map that I liked in Civ V, but a bug in the turn system due to the war I was participating in unfortunately caused me to abandon that game save and world, forcing me to start a new world. That world had a very nice map layout which I loved.  I would like to restart that world using the same seed, but I can't find a way to. Does anyone know how to do this?  Sadly, I don't have a game save prior to when the game-breaking bug occurred.


Can the striker be dismissed, Caught, if the ball is deflected off an umpire?

Can the striker be dismissed, Caught, if the ball is deflected off an umpire before that fielder takes the catch?


I want to create letters with a border. For example, consider this:    The letter on the left is an ordinary "A". The letter on the right is a purple "A" with a black border.  How can I get an "A" with a border? I am labeling an image, so just like subtitles in a movie, the letters will need a border. I will probably need a white border.


Why variance in probability is taken as E[(X−E[X])2]?

Why is the Variance of a random variable X defined as E[(X−E[X])2] instead of E[|X−E[x]|], where E(X) is the Expected Value of X?.  Let's suppose that all values of X are positive, then E[X] must be positive, and X−E[x] is positive for the values of X inferior to E[X] and negative for the values of X which are superior to E[x]. Taking all the positive values and calculate their Expected value E[|X−E[x]|], it would adequately compute the dispersion of X.  Why is the square required in the definition of the variance?


I don't speak Italian but I found some connections from Courmayeur to Milano. Option with train is long, uncomfortable (4 changes) and expensive in comparison to one-change bus connection, but I can't buy tickets in advance via WWW and don't know if there will be enough seats for my group.  I don't know this country, so I'm afraid if it is wise to count on enough seats and just come to the bus at the right time… In addition, there could be some delays because of bike rides as far as I know. Are there some ways to buy tickets on the spot? Maybe ways to book? We can't be too late to Milano.


Prove that $\gcd(2^{2^m}+1,2^{2^n}+1)=1$ if $m,n$ are positive integers.


Physical implementation of gates on IBM Q

There is a lot of quantum gates in IBM Q Composer, however, only few are implemented physically while others can be composed of them.  When one looks at description of a quantum processor in IBM Q interface, there is a list of basis gates. For example those are id, u1, u2, u3, cx for Melbourne processor. However, gates $I$, $U1$ and $U2$ are special cases of $U3$. If one removes statement include "qelib1.inc"; from QASM code, only $CNOT$ and $U3$ gates are left. So, it seems that all single qubit gates are implemented with $U3$ and there is of course two qubits $CNOT$.  According to IBM Q manual, $U3$ gate is implemented by three frame changes and two $X_{\pi/2}$ pulses.  My questions are these:   Which gates are implemented physically on IBM Q? I would expect $CNOT$ and some single qubit gates but which ones? What are frame changes and $X_{\pi/2}$ pulses used for gate implementation?


Example of how the log-sum-exp trick works in Naive Bayes

I have read about the log-sum-exp trick in many places (e.g. , and ) but have never seen an example of how it is applied specifically to the Naive Bayes classifier (e.g. with discrete features and two classes)  How exactly would one avoid the problem of numerical underflow using this trick?


When is the product of $n$ subgroups a subgroup?

Let $G$ be any group. It's a well-known result that if $H, K$ are subgroups of $G$, then $HK$ is a subgroup itself if and only if $HK = KH$.  Now, I've always wondered about a generalization of this result, something along the lines of:  Theorem: If $H_1, \ldots, H_n$ are subgroups of $G$, then $H_1H_2\dots{H_n}$ is a subgroup if and only if ($\star$) holds, where $(\star)$ is some condition on $H_1, \ldots, H_n$, preferably related to how the smaller products $H_{m_1}\ldots{}H_{m_k}$, for $k < n$, behave.  Question 1: Is there such a theorem?  I do know, and its easy to prove, that if $H_iH_j = H_jH_i$ for every $i, j$, then the big product is a group, but this is not satisfying since it's far from necessary (just take one of the groups to be $G$, and you need no commutativity at all). Also, I've been told that there is no really satisfactory answer; if that is indeed the case, then my question would be why? In particular:  Question 2: Are there really problematic counterexamples where you can see that the behavior of the smaller products has nothing to do with the big product, so that no such a theorem can ever exist?  I would appreciate even an answer for the particular case $n = 3$.  Thanks.


Short story where a flexible reality hardens to an unchanging one

In this story, the narrator describes his day as ordinary objects change their physical properties. The floor might suddenly become fluid beneath one's foot, and you'd better get it out fast before the floor becomes solid again. Food on the plate may turn poisonous without any apparent cause. Mountains march on the horizon as the sky changes color. Life is a series of challenges and emergencies that people take in their stride.   It all changes abruptly one day as everything hardens into an unchanging reality. No more inconveniences, but also no more marching mountains in a golden sky. The narrator can't stand the boredom of it, but no one else seems to notice the change.  Read in English in the 1960s or 1970s, probably in an anthology.


How does a circuit "know" the resistance?

This is obviously a very basic question, I'm pretty new to concepts of circuitry and so on. So, lets say you have a circuit with simply a battery, a resistor, and a multimeter measuring the current.  From my understanding, the circuit almost, well, knows(?) the resistance before any current travels. Obviously that's not really possible. But could someone shed some light on how this works? Thanks a ton.


I cannot retrieve process arguments using ProcessStartInfo.Arguments

I want to detect whether a process with a certain name and also specific command line arguments is already running. I use Process.GetProcessesByName to get the list of processes and tried to check the argument field of each processes StartInfo property - it's always empty. Why?  I tried starting with administrative rights. I worked around the issue by using a WMI query eventually, but am not satisfied ...


How do I create a numbered list of words?

I would like to list the keywords for my thesis on the format:   First Keyword, 2. Second Keyword, 3. Third Keyword, ...   But not had to type the numeration manually, so the command would be like:  \mykeywodslist{First Keyword,  Second Keyword, Third Keyword}   Then calling the command:  \printmykeywordlist   Would print them like:  1. First Keyword, 2. Second Keyword, 3. Third Keyword


Cron job as root need to sudo to another user

RHEL6 In root's crontab a have: * 21 * * * /root/script.sh  In script.sh there is a line: /usr/bin/sudo -u jira bash -c 'cd /opt/jira/bin; ./stop-jira.sh' && echo "Jira Shut Down" >> /root/debuglog  The command executes in a regular shell but not when run from cron.   The cron process works fine and the rest of the script executes correctly, it's just the sudo part that doesn't work.  I have updated the script: swapping out sudo for su and tested in another script and it seems to work. I'll test on the actual script tonight and update this post then.  The sudo to su change corrected the issue.  Thanks


What is the use of CDATA inside JavaScript tags and HTML?  <script type="text/javascript">  // <![CDATA[  // ]]> </script>


Let $z_1,z_2,z_3$  be three complex number such that :  $| z_1| = | z_2| = | z_3| = 1$ and $z^3_1 + z^3_2 + z^3_3 +z_1z_2z_3=0$  Then $|z_1+z_2+z_3|$ can take which of the following values ?  (A) $1$ (B) $2$ (C) $3$ (D) $4$    Using the triangle inequality I get $|z_1+z_2+z_3| \leq |z_1|+ |z_2| + |z_3| \leq 3$.   Using the inequality the answers should be (A), (B) and (C).  However, my book says that the answer is only (A) and (B). What is wrong in my method?


Ubuntu 16.04 uses three major kernel lines: 4.4.0 (as a base until the end of life) and 4.8.0 and 4.10.0, and with the release of 18.04, 4.15.0. coming. With automatic software upgrade, only line 4.4.0 is updated a long time ago, but it does not handle (yet) Specter & Meltdown syndrome ... Which kernel should I use and where to get it? ....


Solving exercise 1.10 in Silverman's AEC

Please note that although there is a very similarly titled question  this question received no answers.  Let $p$ be an odd prime and $V_p\subseteq \mathbb P^2$ the variety $$V_p : X^2 + Y^2 = p Z^2 $$ I'm trying to show that $V_p \cong \mathbb P^1$ over $\mathbb Q$ if and only if $p\equiv 1\pmod 4$. The forward direction is easy: suppose $p\cong 3\pmod 4$. If $V_p$ is isomorphic to $\mathbb P^1$ over $\mathbb Q$ then $V_p (\mathbb Q) \cong \mathbb P^1 (\mathbb Q)$. But $X^2 + Y^2 = p Z^2$ has no solutions in integers and thus $V_p (\mathbb Q)=\varnothing$, and we know $\mathbb P^1 (\mathbb Q)\neq\varnothing$.  However I'm struggling to do the other direction because I can't cook up a good isomorphism $V_p \cong \mathbb P^1$ defined over $\mathbb Q$ when $p\equiv 1\pmod 4$. Can anyone help me out with this? Thank you!


So I am learning the difference between global and local vars in Python 2.7 and as per my understanding  local var is one that is defined within a function and  globar var is one that is defined outside of the function.  I created this simple function to test how these local and global vars work when used in combination  def f():     global s     print s     s = "Python is great."     print s    Before I ran the function, I declared the global s  s = "I love python!"  f()   The output was:  >>> f() I love python Python is great   I understand till this part, but what I don't understand is, when I call the run a print s  outside the function, why is it printing the local variable instead of the global one. Does this mean that the global var s is used once and discarded?  >>> print s Python is great   can someone please explain this?


Static variable pass by reference in Java

I have the following in class A:  static ArrayList<Student> students;   I have the following in class B:  public static void populate_students(ArrayList<Student> students) {         students = new ArrayList<Student>(); // ... }   in the debug mode, I see that student is initialized (not null) in the method but after returning to class A, student is null. Why is this the case? I thought that changes made on an object are visible from everywhere in Java.


Prove that among any 100 integers there are always two whose difference is divisible by 99. How can I prove this?


How do you minimise hand washing between every step to keep tools clean?

Say you cooking beef steak:  You have to unwrap the beef from its packaging, lay it down, get blood on your hands, wash hands, sprinkle salt, wash hands, grind pepper, rub the seasoning into the beef, wash hands, grab the tongs etc..  Is it normal to wash hands after every step or is there a trick to avoid getting all the tools dirty?  If you watch TV, they don't ever wash as much as I do.


How do I trick Android to think that it is from a different country?

I installed Android 5.0 on a second-hand HTC One (M7) device which comes from United Kingdom. The ROM 7.17.1540.7 comes from the official , and the  doesn't list any ROMs.  Since then, system update to 7.17.1540.21, performed automatically by the device, fails with the following error:     We have determined that your phone may be running a modified version of its system software. For your protection, we cannot update your phone. Please revert your phone to the official HTC system softwarte to update your phone. If you did not modify your system software or would like help reverting your system, please contact us via the support section at www.htc.com.   Day after day, it downloads the huge update, and shows the same message, again and again.  I contacted the support from United Kingdom. After a long, unpleasant discussion, the person suggested to send the device to the UK repair center in order to reset it, which means lots of trouble of backing up the device and wiping all personal information, and then waiting at least three weeks for it to be “repaired” (given that I live outside UK.)  Is there any way I can either download a UK version of the ROM or trick Android to think either that it's from UK or that the phone is from USA?


There is a consensus in theoretical physics that the singularity at the center of a black hole is a mathematical consequence of the fact that general relativity is a classical theory which does not account for quantum mechanical effects. It is expected that the singularity would be replaced by something else in a theory of quantum gravity.  Since string theory is a theory of quantum gravity, I am interested in what does it have to say about what lies in the center of a black hole where quantum mechanical effects become important. Has anyone worked that out and what were the results?


Someone is not crying at the moment, but you want to ask if that person's character is more like it so, how would you ask?    Are you a crying baby?  Are you a cry baby?


I have a matrix and need to highlight some elements in the matrix. I have found how to highlight a single element (I want to put the cell in the square):  $$ A = \begin{bmatrix} \fbox{0} & \fbox{0} & 0 \\  \fbox{0} & \fbox{0} & 0 \\ 1 & 1 & 1 \\  \end{bmatrix}$$   But how can I outline elements of the submatrix like in the picture below? I need just a frame where some elements are located.


Include figure from Hyperlink continuouly on LaTex

I try to include a figure from a webpage. But I don't have any idea how to do this. Can anyone tell me how to include a figure using [Gummi]


How to add a regression line to randomly generated points using pgfplots in Tikz?

\documentclass{article} \usepackage{tikz} \usepackage{color} \usepackage[active,pdftex,tightpage]{preview} \usepackage{pgfplots} \usepackage{pgfplotstable}  \begin{document}  \begin{tikzpicture} \begin{axis}[ xlabel=Weight (kg), % label x axis ylabel=Height (cm), % label y axis axis lines=left, %set the position of the axes xmin=40, xmax=105, % set the min and max values of the x-axis ymin=150, ymax=200, % set the min and max values of the y-axis ] % add main points \pgfmathsetseed{1138} % set the random seed \addplot[only marks, samples=30, domain=42:100] % show marks, set no. of samples and set the domain of the points {(0.6*x+130)+5*rand}; % equation of the points  \end{axis}  \end{tikzpicture} \end{document}


Is there any steps to enable unity (unable to see my icons and terminal windows)

Which steps do we have to perform in Ubuntu 14.04.2 when there's no icons and terminal window...  How to open a terminal window? Because when I type ctrl+alt+t I still get no response.


Prove that $ \mathbb{E}[XY] - \mathbb{E}[X] \mathbb{E}[Y] = \int_{- \infty}^\infty \int_{- \infty}^\infty (F(x,y)-F_X(x) F_Y(y)) \,dx\,dy,$

I'm studying associated variables now and in one proof the following Lemma is used:  Let $X$ and $Y$ be random variables with distribution $F_X$ and $F_Y$ and joint distribution $F$. Then \begin{align} & \mathbb{E}[XY] - \mathbb{E}[X] \mathbb{E}[Y] \\[8pt] = {} & \int_{- \infty}^\infty \int_{- \infty}^\infty (F(x,y)-F_X(x) F_Y(y)) \,dx\,dy, \end{align} if $\mathbb{E}[XY]$, $\mathbb{E}[X]$ and $\mathbb{E}[Y]$ exist.  The proof begins with introducing to vectors of independent variables:  Let $(X_1,Y_1)$ and $(X_2,Y_2)$ be independent, each distributed to $F$.   Define $I(u,x)=\begin{cases}1& \text{if } u \leq x \\ 0 & \text{otherwise} \end{cases}$.  Then it is said, that  $$ 2 (\mathbb{E}[X_1Y_1] - \mathbb{E}[X_1] \mathbb{E}[Y_1]) = \mathbb{E}[(X_1 - X_2)(Y_1-Y_2)] $$ $$ = \mathbb{E} \left[\int_{- \infty}^\infty \int_{- \infty}^\infty [I(u,X_1)-I(u,X_2)][I(v,Y_1)-I(v,Y_2)] \, du \, dv \right].$$ The first equation is clear for me, but I don't get the second one. Some help would be nice here.  Furthermore the proof ends with the argument, that we can take the expectation under the integral sign since the expectation is finite, thats clear. Then we are ready, but I don't get the right result by calculating.To make the proof fit, we would have to end up at 2 times the right handside of the statement.  What I also observed is that this inequality gives a simple proof for $\mathbb{E}[XY] \geq \mathbb{E}[X] \mathbb{E}[Y]$.


In one piece does the .D stand for Demon or Devil as Celestial's are knowns as Gods And .D is Gods swore enemy


How is HMAC(message,key) more secure than Hash(key1+message+key2)

I understand how for hash functions which are vulnerable to length extension attacks (such as SHA1 and SHA2) it is safer to use a HMAC construction.  What I don't understand is, how or why is $\operatorname{HMAC\_SHA256}_\mathrm{key}(\mathrm{message})$ safer (in terms of resistant against certain attacks) than $\operatorname{SHA256}(\mathrm{key}_1 \mathbin\| \mathrm{message} \mathbin\| \mathrm{key}_2)$, assuming that all key strings are sufficient in length and entropy?


Fatal error: Call to undefined function file_save()... while uplaoding user picture programatically

I have two drupal 7.x sites, and I am uplaoding user picture programtically using the bleow code. In one site it is working fine and another one is getting fatal error as shown below. what could be the problem here..  Fatal error: Call to undefined function file_save() in /...   Code to upload user picture programatically.  $tmp_photo_realpath = "images/".$userimgname;         $tmp_photo = "images/".$userimgname;           $file = new stdClass();           $file->uid      = $uid;           $file->status   = 0; // mark the file as temporary           $file->filename = basename($tmp_photo_realpath);           $file->uri      = $tmp_photo;          // $file->filemime = image_type_to_mime_type(exif_imagetype($tmp_photo_realpath));           $file->filesize = filesize($tmp_photo_realpath);          $infofile = explode("/",$tmp_photo);            $infoext = explode(".",end($infofile));         $imgext = end($infoext);        // The file should be an image       $errors = array();       $errors += file_validate_is_image($file);       $errors += file_validate_image_resolution($file, variable_get('user_picture_dimensions', '100x100'));       $errors += file_validate_size($file, variable_get('user_picture_file_size', '30') * 1024);        // Make sure file extension is a valid image       if (!in_array(strtolower($imgext), array('jpg', 'png', 'gif'))) {         $errors[] = ' invalid image file extension.';       }        if (count($errors)) {         drupal_set_message(t('Profile Image Import:') . ' ' . $errors[0], 'warning');         // Clean up (set fid to avoid error messages)         $file->fid = 0; file_delete($file);       }       else {         // We'll need a valid file id on the file object; file_save() will give us one         $file = file_save($file);         // Update user account (fid is not empty, status is temporary -- image         // will be moved to proper directory and assigned to the user)         $fields['picture'] = $file;         $account = user_save($account, $fields);     }


How is there energy transferred when net work done is zero?

Consider a system on the level ground (let this be the datum line). Only gravitational force(force 1) and a vertically upward force(force 2) are acting on it and there is no heat transfer. When the upward force, force 2, is greater than gravitational force, force 1, there is a net-upward force which causes the system to accelerate up. After a certain distance, force 1 and force 2 become equal and the system starts moving at a constant velocity. The net-upward force multiplied by the distance traveled gives the work done on the system by the net-force which is equal to the increase in kinetic and potential energy of the system during acceleration.   Now, when it is moving at a constant velocity, as there is no net force acting on the system, the net-work would be zero. But still, the potential energy is increasing with the kinetic energy remaining constant. How is the energy in the system increasing without any work being done on it?


Can someone explain what each step in this does?   I have never seen "for i in X:" used where X is a generator, and I am failing to understand how the i interacts with the function if it's not being inserted between the ().   def fib():     a, b = 0,1     while True:         yield b         a,b = b, a + b for i in fib():     print(i)


I'm rendering a cartoon figure, it's working fine in Render preview, but missing the feet in final render. This always happen when the cartoon is far from the camera. I have set the camera Clip End to 2000 but still the same. Could anyone help to identify the problem? Thanks a lot!  The Render preview:    The final render:


How to import Dump of 12.2 to 12.1.0.2.0 (Higher to lower version)?

I took a backup of one database using expdp utility. Unfortunately, this database had been corrupted. I have another oracle server installed on another machine. I want to import available dump to this database. But this available database is in lower version 12.1.0.2.0. ORA-39001: invalid argument value ORA-39000: bad dump file specification ORA-39142: incompatible version number 5.1 in dump file "D:\DB Administration\Backup Guides\Oracle Docs\dump\BACKUP_FULL_20200625.DMP" I have tried expdp and sql developer to import in oracle 12.1.0.2.0. Found not a valid export. OS: Windows server 2016 Utility : expdp


My computer is wired to my audiomixer and then to my headphones. If i turn the volume off my mixer up i can literately hear my computer(if my computer is'nt playing audio ofcourse). I can hear  it when i maximize or minimize a window. I can hear my mouse hovering over a link in a browser,..  I have multiple soundcards, and only the one on my mainbord gives me this "interference" How can it be that i can hear software? Is there anyone here that can give me an explanation.


For questions I'd like to keep an eye on (e.g. to see if anyone else posts an answer) is there a way to maintain a list of such questions other than adding them as favourites or using the RSS feeds?


My 3yr son wont tell me when he needs to go to the bathroom

When my son was two he started letting me know when he wanted to go to the potty. He then started nursery and went back to old ways of not letting me know.   He's now three and I've taken him out of diapers however he still wont go. He will sit on the toilet but wont go until we've pulled his pants up.  How can I encourage him to (1) Tell us when he needs to us the bathroom and (2) Go to the bathroom when he IS sitting on the toilet.


UK Standard Visitor Visa: How to mail multiple applications when applying as a family

I am a permanent resident of USA. I am making a trip to India but planning a stop-over in London,UK for a week. For this stop-over , I am applying for a standard visitor visa. My biometric appointment has already been completed. Now I have to send applications for the visa for both me and my wife.  1.) Should I send both applications in same envelope? Maybe, put each application in small envelope and then put both applications in a bigger envelope?  2.) Should I put my financial documents (Bank statements , Pay Slips) in both applications(i.e. mine and my wife's)?  3.) I have an old passport which is expired. Is there any need to send this passport as well with my application?  Thanks!


How to show "Done" button on iPhone number pad

There is no "Done" button on the number pad. When a user finishes entering numeric information in a text field, how can I make the number pad disappear?  I could get a "Done" button by using the default keyboard, but then users would have to switch to the numeric keys in order to input numbers. Is there a way to show a "Done" button on the number pad?


Irreducibility of polynomial $x^k-x^{k-1}-\ldots-x-1$

Can anybody give us a hint how to prove  the irreducibility of polynomial  $x^k-x^{k-1}-\ldots-x-1$ over $\mathbb{Q}$ ?  Thanks in advance. Dusan


What features of Mavericks are beneficial to you?

This question serves to share and collect the enhancements that make a large difference to how you use your Mac.   Please post one feature per answer. Please also check to see if your answer has already been posted - duplicate answers will be deleted. To search answers for this question use  (directly from the question page) in addition to your search terms in the search box in the upper right hand corner of this page.  The best answers will not only list a feature, but provide details on how to configure that feature, and provide an image of how to use the feature to be more efficient or effective with Mavericks.


I want to ask about infinitesimals and non-standard analysis. In physics we always use $\mathrm dx,~\mathrm dv,~\mathrm dt$ etc. as infinitesimal quantities. When we deduce equations in physics, when we set up integrals and in many other instances we use infinitesimals. For example in the first law of thermodynamics we have: $đQ=\mathrm dU+đW$.  Now when we ask teachers about what is $đQ$ here, they say it is an infinitesimal amount of thermal energy. So my question is, is it necessary to treat the whole non-standard analysis as an axiom for physics or do we have standard calculus explanation for physicist's use of $\mathrm dy/\mathrm dx$ as a quotient in all cases?


I've got raw files using Magic Lantern on a Canon 5D Mark II. I've converted them to DNG files then I've converted those DNG files using adobe DNG converter. But I've now don't know how to edit the images?   Is this possible in Blender somehow? At the moment when I go to the image tab to import the images Blender can't see the DNG files what can I do to actually benefit from obtaining raw files?


Let $f:X \to Y$ be a function.   Then $f$ is one-to-one iff for all subsets $A$ and $B$ of $X$, $f(A\cap B) = f(A) \cap f(B)$.  Any proofs or guidance would be greatly appreciated


I am trying to reload an iframe. Normally the code is achieved without iframe via below code: window.location.reload(true)  <iframe  src="https://maps.google.com/maps?f=q&amp;source=s_q&amp;hl=en&amp;geocode=&amp;q=eiffel+tower&amp;aq=&amp;sll=41.228249,-80.661621&amp;sspn=11.149099,23.269043&amp;ie=UTF8&amp;hq=&amp;hnear=Eiffel+Tower,+5+Avenue+Anatole+France,+75007+Paris,+%C3%8Ele-de-France,+France&amp;t=h&amp;ll=48.858186,2.294512&amp;spn=0.002471,0.00456&amp;z=17&amp;output=embed" id="iframeSupplierNumberSearch" height="200" width="300" title="Iframe Example"></iframe>  I have tried the following: // var myFrame = document.querySelector('#iframeSupplierNumberSearch'); //var iframe = document.getElementById('iframeSupplierNumberSearch'); // myFrame.contentWindow.location.reload(true);    // document.getElementById('iframeSupplierNumberSearch').contentWindow.location.reload() //document.getElementById('iframeSupplierNumberSearch').src += '';  // document.getElementById('iframeSupplierNumberSearch').src = window.location.href;   //document.getElementById('iframeSupplierNumberSearch').contentDocument.location.reload(true);      //document.getElementById('iframeSupplierNumberSearch').contentWindow.location.reload; // window.frames['iframeSupplierNumberSearch'].location.reload(true); //document.getElementById("iframeSupplierNumberSearch").src = window.location.reload(); //document.getElementsByTagName('iframeSupplierNumberSearch')[0].src = document.getElementsByTagName('iframeSupplierNumberSearch')[0].src //  document.getElementById('iframeSupplierNumberSearch').contentWindow.location.reload(); // document.getElementById('iframeSupplierNumberSearch').contentWindow.location.reload; // window.frames['iframeSupplierNumberSearch'].location.reload(); //window.location.href = window.location.pathname + window.location.search + window.location.hash; //location = location;  Can you let me know how to reload the an iframe via windows.location.reload(true);?


I have this matrix but I would like the second element in the second row to be highlighted, is that possible? I have tired everything!!! this is what I have so far... \begin{bmatrix} 1 & 2 & 3\\ 2 & 3 & 1\\ 3 & 1 & 2 \end{bmatrix}


A smooth function separating two disjoint closed subsets

I'm trying this problem (2.14) in John M Lee's book on smooth manifolds:      For any two disjoint closed sets $A$ and $B$ we can find a smooth function such that $f^{-1}(1)=A$ and $f^{-1}(0)=B$.    Can someone give a hint on how to do this?   I tried to use normality and partition of unity and the fact that for any closed set $K$ there is a smooth function $g$ such that $g^{-1}(0)=K$. But none of these seem to work.


If $X,Y$ are CW  complexes and $f$ a cellular map from $X$ to $Y$, is it true that $M_f$ is a CW complex?


How to treat uppercase and lowercase words the same in Python

Code:  str1 = input("Please enter a full sentence: ") print("Thank you, You entered:" , str1)  str2 = input("Now please enter a word included in your sentence in anyway you like: ")  if str2 in str1:     print("That word was found!") else:     print("Sorry, that word was not found")   I have done some research on forums etc and the only solutions i can find for this subject are converting words into uppercase/lowercase. I don't want to do it like that.  I want something that will ignore the fact that it is uppercase or lowercase and will assume it to be the same word, so when someone inputs a sentence it will automatically assume it t be the same word. For example: (Treat = treat, TREAT, TreAT etc). So it will essentially read the characters in the word and will ignore the uppercase/lowercase letters.   I do have something (string.ascii_letters) which i think might do it, but if anyone know any better way of doing it then that would be greatly appreciated! :)


Omission of "the" in "elected him president" and "made captain"

Why is there no the before president and captain?     They elected him president.       She was made captain of the team.


How to get all combinations with no repeats?

So, I started off with this array:  array = ['A', 'B', 'C', 'D', 'E', 'F']  And I played around for a little while before getting python to print each unique, non-repeating combination, like so:  AB, AC, AD, AE, AF, BC, BD, BE, BF, CD, CE, CF, DE, DF, EF,   But now, I'd like to take all of these into a new array:  array2 = ['AB', 'AC', 'AD'...., 'EF']  And print all 3-element-long combinations, not including rearrangements, that have no repeats.  What I mean by 'no repeats':  AB, CD and EF is a 3-element long combination with no repeats, but AB, BD and EF is a 3-element-long combination with repeats, as 'B' appears in both 'AB' and 'BD'.  What I mean by 'not including rearrangements':  AB, CD, EF would be the same as BA, DC, FE, because all of the 2-letter elements are the same (BA is AB rearranged, DC is CD rearranged, and FE is EF rearranged). So ideally it'd print something like:  AB CD EF, AB CE DF, AB CF DE, AC BD EF, AC BE DF, AC BF DE, AD BC EF, AD BE CF, AD BF CE, AE BC DF, AE BD CF, AE BF CD, AF BC DE, AF BD CE, AF BE CD,   I believe those are all the combinations where no 2-letter element is repeated.  How would I go about printing this? Thanks!


regex for mobile number validation in java

I want to have phone number in working combination of '0' followed by 10 digit mobile number (or) 0091 folllowed by 10 digit mobile number (or) +91 followed by 10 digit number.  1) 0 followed and +91 folowed numbers are working with following regex i also want 0091 followed number to be worked, my regex is:  "^([0]|(?:[0][0]|\\+)(91))([7-9]{1})([0-9]{9})$";   Could you suggest me working a regex.


Why is "nodev" in /etc/fstab so important? How can character devices be used for hacking?

I am learning about linux security and struggling to understand why a USB stick with a character device on it is potentially dangerous.  If I have a USB stick with a bash executable that has setuid root on it, the danger is obvious: Anybody with such a USB stick can gain root privileges on my computer if I have an entry like   /dev/sdb1 /media/usbstick auto defaults 0 0   in my /etc/fstab because defaults includes suid.  But what about character devices? How can I use a character device to gain root privileges or break stuff if a USB stick with a character device on it gets mounted with dev or defaults?


I have a set of two nodes and I would like to draw tight ellipses around them in my tikz picture. Note that this is part of a beamer presentation.    I have attached an image that illustrates the wanted effect.    Here is what I have so far:  \documentclass[10pt,aspectratio=1610]{beamer} \usepackage{tikz} \usetikzlibrary{shapes,arrows,backgrounds,fit,positioning}  \begin{document}  \tikzset{res/.style={ellipse,draw,minimum height=0.5cm,minimum width=0.8cm}} \tikzset{literal/.style={rectangle,draw,minimum height=0.5cm,minimum width=0.8cm,text width = 1.2 cm, align = center}}  \begin{frame}[fragile]{Example}{} \begin{tikzpicture}[node distance = 2 cm,auto, ] \node[res,] (obs1) {\footnotesize :obs1} ; \node[res, left = 1cm of obs1] (shop1) {\footnotesize :shop1} ; \node[literal, left = 1cm of shop1] (shopName1) {\footnotesize ``Barnes \& Noble''} ; \node[res, above of = shop1] (book1) {\footnotesize :book1} ; \node[literal, left = 1cm of book1] (bookName1) {\footnotesize ``Dune''} ; \node[res, below of = obs1] (obs2) {\footnotesize :obs2} ; \node[res, left = 1cm of obs2] (shop2) {\footnotesize :shop2} ; \node[literal, left = 1cm of shop2] (shopName2) {\footnotesize ``Amazon''} ; \node[res, below of = shop2] (book2) {\footnotesize :book2} ; \node[literal, left = 1cm of book2] (bookName2) {\footnotesize ``Dracula''} ; \node[literal, below of = obs2] (measure2) {\footnotesize 12} ; \node[literal, above of = obs1] (measure1) {\footnotesize 7} ; \node[literal, right = 1cm of obs1] (monthName) {\footnotesize ``January''} ; \node[literal, right = 1cm of measure1] (yearNum) {\footnotesize ``2016''} ; \node[res, right = 1cm of monthName] (month) {\footnotesize :january2016} ; \node[res, above of = month] (year) {\footnotesize :2016} ; \node[res, below of = month] (day) {\footnotesize :date31012016} ;  \path[->,draw]     (obs1) edge node[midway,above=-6pt,fill=white,inner sep=0pt] {\footnotesize :shop} (shop1)     (obs2) edge node[midway,above=-6pt,fill=white,inner sep=0pt] {\footnotesize :shop} (shop2)      (obs1) edge node[midway,above=-6pt,fill=white] {\footnotesize :book} (book1)     (obs2) edge node[midway,above=-6pt,fill=white] {\footnotesize :book} (book2)      (book1) edge node[midway,above=-6pt,fill=white,inner sep=0pt] {\footnotesize :name} (bookName1)     (book2) edge node[midway,above=-6pt,fill=white,inner sep=0pt] {\footnotesize :name} (bookName2)      (shop1) edge node[midway,above=-6pt,fill=white] (title1) {\footnotesize :title} (shopName1)     (shop2) edge node[midway,above=-6pt,fill=white] (title2) {\footnotesize :title} (shopName2)      (obs1) edge node[midway,above=-6pt,fill=white] {\footnotesize :price} (measure1)     (obs2) edge node[midway,above=-6pt,fill=white] {\footnotesize :price} (measure2)      (obs1) edge node[midway,above=-6pt,fill=white]  {\footnotesize :date} (day)     (obs2) edge node[midway,above=-6pt,fill=white] {\footnotesize :date} (day)      (day) edge node[midway,above=-6pt,fill=white] {\footnotesize skos:broader} (month)     (month) edge node[midway,above=-6pt,fill=white] {\footnotesize skos:broader} (year)      (month) edge node[midway,above=-6pt,fill=white,inner sep=0pt] {\footnotesize :month} (monthName)     (year) edge node[midway,above=-6pt,fill=white] {\footnotesize :year} (yearNum)     ;  \begin{pgfonlayer}{background}   \node[fit=(shopName1)(shop1), fill=violet!30,ellipse] {};   \node[fit=(shopName2)(shop2), fill=violet!30,ellipse] {};   \node[fit=(bookName2)(book2), fill=violet!30,ellipse] {};   \node[fit=(bookName1)(book1), fill=violet!30,ellipse] {};   \node[fit=(measure1)(obs1), fill=blue!30,ellipse] {};   \node[fit=(measure2)(obs2), fill=blue!30,ellipse] {};   \node[fit=(year)(yearNum), fill=green!30,ellipse] {};   \node[fit=(month)(monthName), fill=green!30,ellipse] {}; \end{pgfonlayer} \end{tikzpicture} \end{frame} \end{document}   Here is the result that it produce    Note how the ellipses do not fit the nodes but cover much more. How can I create a tight ellipse around a pair of nodes?


Ubuntu won't recognise and use my nvidia geforce gtx 1050 ti GPU

Hello wizards of linux,   I'm a complete linux noob, though I've got experience with nearly every windows after 98. I just built a new pc and while I wait for my windows installation disk to ship I decided to install ubuntu and check it out.  After installation, I opened one of my favorite linux compatible games, xonotic (www.xonotic.org), only to find my FPS count was horrid. I quickly realized that linux wasn't using my GPU. First, I checked my BIOS to make sure it was set to actually use it by default, which it was. Then, I went back into ubuntu. I figured ubuntu needed a driver installed, so I went to the driver manager only to find out that the only device on the list was errored and unidentified. Wonderful, eh? So, I realized that I couldn't install the driver from there, so before I did anything else I ran some command I found that would show me my gpu stats, and as expected the only thing ubuntu knew was that it was an nvidia card. Helpful!  Well, I had no way of knowing whether or not the GPU was broken, and due to my monitor being plugged into it's dvi port I thought it was fine.  So, I downloaded the driver and fiddled around for an hour before I figured out how to install it. I installed it, and I got the same issue.  I noticed a lot of other people are having similar problems, does anybody here know the solution? Until I get windows in some days, I won't know if something is actually wrong with my GPU.  Also, thanks for listening to a complete noob.


Why does my text object look weird along its edge?

I am new to blender, and after I created a text object, I found it had a black material along its edge.  Here is view display and render display, which shows the problem. I don't know understand what is causing this. It looks unrealistic and bad—is there any way to beautify it?


Suppose that $(X,\mathcal{E},\mu)$ is a non-atomic finite measure space (i.e. for every $E \in \mathcal{E}$ with $\mu(E)>0$ there exists $F \subset E$ measurable such that $0<\mu(F) <\mu(E)$.)  a) Prove that for every $ \varepsilon >0$ there is a finite partition of $X$ in measurable subsets $X_1,..,X_n$ such that $\mu(X_i)\leq \varepsilon$.  b) Prove that for every $\alpha \in [0,\mu(X)]$ there exists $E \in \mathcal{E}$ with $\mu(E)=\alpha$.    I guess that a) is given to prove b) more easily. I have the following idea of solution for a) (inspired from , which proves b)  )  Denote  $$ \Gamma = \{ (X_1,..,X_n) : n >> \mu(X)/\varepsilon, X_i \text{ are disjoint }, \mu(X_i)\leq \varepsilon \}$$ ordered by componentwise inclusion. Totally ordered parts $(Y_\alpha)$ of $\Gamma$ have an upper bound element $(\bigcup Y_\alpha^i)_{i=1}^n$ which is still in $\Gamma$.   By Zorn's lemma $\Gamma$ has maximal elements. If a maximal $(X_1..X_n)$ element is not a partition, then we can replace it with something better, of the form $(X_1,..,X_n\cup A)$ where $A \subset X \setminus (X_1 \cup..\cup X_n)$ and $\mu(A)>0$.     My questions are:  1) Is my solution of a) correct? I feel that the part with the upper bound element may not work, since there might be noncountable unions.  2) What is a simpler solution of a)?


How to split python string every nth-1 + nth char

For example, suppose we have a string:  'abcdefg'   And we need to get a list like this:  ['ab', 'bc', 'cd', 'de', 'ef', 'fg']   we should not use any kind of library  Here is my solution:  def str_split(s):     s = iter(s)     ch1=''     ch2=''     chars_list=[]     while True:         try:             ch1 = ch2 or next(s)             ch2 = next(s)             chars_list.append(ch1 + ch2)         except:             break     return chars_list   I wonder is there a better solution? Maybe it is possible to use list comprehension like ?


Inverse Laplace transform for Gaussian function

I am trying  to find the inverse Laplace transform of the Gaussian function  $$ G(s)=e^{-cs^2}$$   $L^{-1}\left\{G(s)\right\}= ?$ Where $c> 0$.


It doesn't seem I can get my meta tags to appear on the page--front.tpl.php on a Drupal 7 site.  I feel like I have all the correct settings in the Meta tags module configuration, and I have cleared all caches. It works perfectly fine for all pages, just not the front page. This is driving me bonkers.  Any ideas?


Attempting official deploy process with single sandbox may reset/remove all existing work?

I've been working on a small consulting project for ~3 mo (100 hours), mostly Apex with a little configuration.  I used a sandbox per recommendation.  I started to work on the deploy process today and per official recommendations as I read them updated my developer sandbox first, after backing it up as best I could easily.  Of course, the refresh blew away all my work:  my code and my configuration.  No option was provided to refresh less.  Why does Salesforce tell you to follow a process that deletes all your work?  I guess there was some implicit understanding I was supposed to have created some sort of changeset first?  Was there some way to know that??  If they really want you to start fresh, couldn't they at least provide a backup option that backs up more than just your data?  Or at least a prominent warning in the deploy documentation?  Is there any easy way to get my work back?  (I'm not a total idiot;  the Apex code I spent dozens of hours on is in my code repository and I can upload the files again and rebuild the trigger config.)  Official deploying doc I was trying to follow:


I have a javascript coding exercise to do which has got me a bit stuck (I'm only just starting javascript).  The exercise is as follows:  Write a function multiply(a) that returns a function capable of multiplying by a. Call this function with b as a parameter.  So far I have the main skeleton (not difficult):  function multiply(a) {     return //Stuck here }   I'm not sure if the question is to call multiply(b) and have it give us the result of a*b or something else...  I tried writing a function directly after the return statement but this just printed out the function name.  function multiply(a) {     return function f { return a * b } //Here I assume b is a variable defined somewhere }   Thanks in advance!


How can I specify a different style for (a difficult to describe concretely) part of a line?

I'm in the following situation: Using TikZ, I have drawn a curve which is fairly simply described:  \documentclass{article} \usepackage{tikz} \begin{document} \begin{tikzpicture} \draw (1,1.5) .. controls (1,2.25) and (-1,2.25) .. (-1,2)         node[pos=0,anchor=west]{-1}         .. controls (-1,1.75) and (1,1.75) .. (1,2.5)         node[pos=1,anchor=west]{0}         .. controls (1,3.25) and (-1,3.25) .. (-1,3)         .. controls (-1,2.75) and (1,2.75) .. (1,3.5)         node[pos=1,anchor=west]{1}; \end{tikzpicture} \end{document}   However, now I'd like to specify a different style for part of this curve; It happens that the part of this curve I'd like to do something special with is not easily described explicitly. In this particular case, I'd like to apply the style [(-),thick,red] to some arbitrary segment of the curve. I'm looking for an efficient and simple way to do just that.  I was hoping that there might be an option to do something along the lines of \draw[only between 0.2 and 0.8] "curve description", but I'm not aware of any such possibilities.   For extra concreteness, here is a (Paint-made) picture of something like what I'm looking for:


How can I hide my profile on Stack Exchange sites?

I am planning to hide my profile on one of the Stack Exchange sites. I am not asking to hide my network profile. While that would be my main goal, but I know that is not possible. I want no one can click on my username to see my profile page. That way I have effectively disabled my network profile. I have seen a couple of users have done this.  See that no one can click on the user name above. I understand it can happen if the user is deleted. But I have seen other users which were relatively newer like asked question yesterday but there usernames were not clickable.  Is this feature available somewhere?  If not do I have to request it on this particular Stack Exchange site to make my profile hidden? If yes, how?


I am writing a report using scrbook document class. I am creating the reference follows  @ARTICLE{example, author = {A Ho, B.C Stuber and D.E Walter}, title = {IEEE Standard Definitions of Terms}, year = "1993", journal = "IEEE Std. 145-1993",  }   However, when I compile the file the term IEEE appears as Ieee and the authors name appears as B.C.S.A Ho and D.E Walter. I am using the cite package (\usepackage{cite}) and making the reference as   \bibliographystyle{IEEEtran} \bibliography{references}  %references.bib contains the bibliography script.   I want IEEE to appear as IEEE and not Ieee and the names to be ordered properly. I would highly appreciate if someone tells me how to solve this issue.


Tried to install Inkscape but I'm getting this error.  GPG error:  stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY D615560BA5C7FF72  I hope someone can help.


Can scripts run even when they are not set as executable?

I can seem to run scripts (.sh) with and without them being set as executable. So where exactly this matters?


normal approximation to the binomial distribution: why np>5?

Nearly every text book which discusses the normal approximation to the binomial distribution mentions the rule of thumb that the approximation can be used if $np\geq5$ and $n(1-p)\geq 5$.  Some books suggest $np(1-p)\geq 5$ instead.  The same constant $5$ often shows up in discussions of when to merge cells in the $\chi^2$-test.  None of the texts I found gives a justification or reference for this rule of thumb.  Where does this constant 5 come from?  Why not 4 or 6 or 10?  Where was this rule of thumb originally introduced?


How to upgrade from 13.10 beta to stable release?

I installed 13.10 when it was either in beta/alpha, and now would like to upgrade to the official release. How should I go about this? Should I just make a new install disk and use that? Any help is much appreciated.


Why are my SEDE results inaccurate/obsolete/incorrect/outdated?

When I use , the results I get don't reflect recent activity. Sometimes the data I get back are two months out of date. What's wrong? This is intended to be a canonical reference for questions about SEDE not reflecting real-time results.


USB flash drive is showing no media status, how to repair the USB drive irrespective of the data loss?

So I tried converting a USB flash drive (16 gb) to live usb for a Linux distribution, Not going into details, it ended with me deleting those files and trying to format the USB drive and this happened to the USB drive.  I tried formatting it, and it showed "There is no disk in drive E: Insert a disk, and then try again." Then I tried using disk management, changing the letter and so on, and it showed this  I also tried using deskpart, but it still didn't worked. It showed: Disk ###  Status         Size     Free     Dyn  Gpt --------  -------------  -------  -------  ---  --- Disk 1    No Media           0 B      0 B  What should I do to make the usb drive workable again? I am fine if all the data is lost because it wasn't important, but I would like the USB drive to work again.


When submitting a journal article, can I cite a paper which cited my arxiv preprint?

I had uploaded an arxiv paper about 4 months back which developed an algorithm. After uploading the preprint we got some good feedback from a colleague, following which we have added additional simulation results and a more detailed discussion.   In this span of 4 months, the paper has been cited a couple of times. The original work was primarily theoretical, whereas the papers which cited our work successfully applied our algorithm (with minor modifications) to power systems. Hence, when submitting to the journal, I would like to cite these papers to show that our methods have practical application.  My question is: would this form a citation loop which is undesirable? They have cited my work, and I cite their work. Is this firstly even allowed?  Field of research: Intersection of applied mathematics, engineering, and computer science. The paper is likely to be submitted to a SIAM journal.


If I create two workflow rules, the first being  Whenever a case is opened, set Example Case Field to A   and the second being  Whenever a case is opened, set Example Case Field to B   how does Salesforce determine the order of execution?


Layover at Tokyo Narita airport: can I travel outside, and what kind of visa would I need?

I am travelling from Singapore to San Francisco and the airline has a layover of 7.5 hours at Tokyo Airport (NRT). I am wondering if I would be allowed to go out to experience the city for a while in some form a visitor visa.  I know Singapore has such facilities, but does anyone know if I can do it in Tokyo? Any suggestions or pointers are welcome. Note - I do not have a visa for Japan yet, but I am hoping that 1 day visitor visa could be possible at airport.


I need to develop an app for iphones. I have a laptop that runs on ubuntu. Can we develop the complete code, run and test it on ubuntu machine?   Thanks


I am very new to QGIS and I simply have two tif images which I need to do pixel analysis on so I can compare the change in vegetation over time. I have no idea how to go about this and if anyone has some advice for me I would be very grateful


Not as popular as the Copenhagen interpretation perhaps, but I'm truly intrigues to know the intricacies of the de Broglie-Bohm Theory. However, I could find absolutely no source which could teach me the same (unlike the innumerous texts on Copenhagen Interpretation). Does anyone have any idea where it can be studied from? Note that  is on a much narrower sub-topic and its answer is not really relevant here.


Should “If I ever had a philosophy” be in the past perfect?

Excerpted from The Hills of Triumph:     If I ever had a philosophy with which to govern my social life, even long after learning that social is often at the detriment of personal, it would have been no dfferent.   To use the subjunctive for a past thing, we usually use the past perfect, so must I ever had be changed to I ever had had?  I’m not sure, because the presence of ever seems to give us a hypothesis extending to now, justifying the past simple, which can be used for a present hypothetical situation in the protasis.


Why are Castiel's wings still broken? Can he now teleport?

In Supernatural the "Book of the Damned" Castiel managed to      retrieve his grace, although we can see that his wings are broken.   However, Castiel lost his grace before Metatron expelled all of the angels from heaven, so when all of the angels had their wings irreparably damaged, Castiel was already human?      So what happened to make his wings like that? Or was it not necessarily the drop to Earth that damaged the angels, or the spell itself that Metatron cast? Or am I just wrong in assuming his wings looked broken?


Why does "grep '.*[s]' file" work and "grep .*[s] file" doesn't?

Comparing     grep '.*[s]' file   with     grep .*[s] file   Why do you need quotation marks to let this work properly? In the second case, grep seems trying to inspect every file with a period.


Is there any way to upload a screenshot from an iPad to this site (or other StackExchange sites)?

So I capture a screenshot with my handy "[HOME]-[POWER]" combo, and draw freehand arrows on it in Adobe Ideas (because I like their line smoothing) to highlight my problem, but:  How do I upload this picture to Ask Different from the iPad?


Using Newton's Law of Universal Gravitation to find distance (r), with the question not giving sufficient information to substitute into the equation.

The problem is described as follows:  Newton's Law of Universal Gravitation: $F=G \frac{m_1 m_2}{r^2}$ for any point masses $m_1,m_2$ with the distance between them $r$.    The factor $G≈6.67∙10^{-11}  N(m/kg)^2$ is a universal constant.  Denote the mass of Earth as $m_E≈5.972∙10^{24}  kg$,  the mass of the Moon as $m_M≈7.348∙10^{22}  kg$.  The unknown mass of the object will be $m$ and the distance in question will be $R$.  Then the distance between the object and Earth is  $\frac{1}{10} R$ and the distance between the object and the Moon is $\frac{9}{10} R$. The force from the Moon and Earth acting on the object is equal.  Now, I worked on the problem and found that from the law we obtain:  $$G \frac{mm_E}{\left(\frac{9}{10} R\right)^2} =G \frac{mm_M}{\left(\frac{1}{10} R\right)^2}$$  It seems like there is no solution to the question as not enough information is given. However, I was given this question as an assignment in math class and believe that steps should be shown towards a solution whether it exists or not. I fail to see how to solve this problem, at least to an approximate value, which is what is needed. If anybody knows, help will be immensely appreciated. Thank you.


I am wondering why do I get NPE in the following code:   @Override public void updateItem(String item, boolean empty) {     if(empty){         super.updateItem(item, empty);         return;     }     MyTableRow currentRow = (MyTableRow) getTableRow().getItem();     currentRow.stringProperty(); // here I get NPE }   The code snippet is from a custom TableCell, where the updateItem is overridden. At the commented line I get NPE, while the item is not null, and also empty is false. For me that means there is a row, so the getTableRow().getItem() should not be null. That is true and is a solution(or an unnecessary workaround?) to make a nullcheck after I get the item's reference, but I think that is unnecessary. Did I missed or this is an expected outcome?


Find the determinant of the nbyn matrix of p as its diagonal entries and 1 else where.  I tried to solve the problem via two methods, to no avail. First was reducing the matrix by elementary row operations to an 'almost diagonal matrix looking a bit like the jordan form but the first row cant be eliminated posing aproblem.  second I tried to use the definition of determinant by p^x by choosing x number of p from n, then finding how many ways are there to permute the rest of the ones, but I cant find a way to resolve the signs.


I created an IBM Quantum account but I am unable to login and I get this message - Your IBM Quantum account has been disabled. What should I do to get this resolved?


Is there an error in the universal monster rules for table:natural attacks by size?

I am working on a druid character and just getting around to wild shapes natural attacks and I spotted what should be an error in its damage progression under the  which conflicts with the newer .  Official Damage Dice Progression Chart $$ \begin{array}{l|l} \text{Level} & \text{Dice}\\ \hline 0 & 0 \\ 1 & 1d1 \\ 2 & 1d2\\ 3 & 1d3\\ 4 & 1d4\\ 5 & 1d6\\ 6 & 1d8\\ 7 & 1d10\\ 8 & 2d6\\ 9 & 2d8\\ 10 & 3d6\\ 11 & 3d8\\ 12 & 4d6\\ 13 & 4d8\\ 14 & 6d6\\ 15 & 6d8\\ 16 & 8d6\\ 17 & 8d8\\ 18 & 12d6\\ 19 & 12d8\\ 20 & 16d6\\ \end{array} $$  Here we have the chart for Bite  $$ \begin{array}{l|l|l} \text{Size} & \text{Dice Level} & \text{Dice}\\ \hline Fine & 1 & 1d1\\ Diminutive & 2 & 1d2\\ Tiny & 3 & 1d3\\ Small & 4 & 1d4\\ Medium & 5 & 1d6\\ Large & 6 & 1d8\\ Huge & 8 & 2d6\\ Gargantuan & 9 & 2d8\\ Colossal & 12 & 4d6\\ \end{array} $$  Here we can clearly see that huge to gargantuan is only 1 and not 2, and from gargantuan to colossal is 3 instead of 2. If gargantuan was changed from 9 to 10 then the chart would be correct, its the only value that's off. So is this just a mistake or is this actually what its suppose to be?


If$f_n$ a sequence of integrable functions on a set of finite measure which converge to f uniformly, then the limit and integral can be swapped.

Hello I came across this problem and tried to prove it, I would just like to confirm that my proof is correct please as I think there is something wrong with it.   The problem says the following: Suppose $(f_n)$ is a sequence of integrable functions on a set A of finite measure. Show that if the sequence is uniformly convergent on A, then $\lim_{n\to \infty} \int_{A} f_n dm= \int_{A} \lim_{n\to \infty} f_n dm$.  My attenpt: Let $\epsilon>0$ be fixed but arbitrary. Then by uniform convergence,there exists an N s.t. $|f_n-f|<\epsilon$ for all n>N. Then $0\leq \int_A |f_n-f| \leq \epsilon m(A)$ for all n>N.  Now since $\epsilon>0$ arbitrary and $m(A)<\infty$ then $\int_A |f_n-f| \to 0$ which implies $0<|\int_{A} (f_n-f)| \leq \int_{A} |f_n-f|$ and now taking the limit gives the desired result.  Could someone verify my proof? I am not sure when steps like since epsilon is arbitrary work.Also where did I use integrability of the $f_n$ ? Thanks.


What is a determinant in matrix ? NOT how to get it but WHAT is it in real life

We know to get determinant in a matrix we use sarrus, laplace, x methods and so on But question : WHAT is it, according to some pages is about permutations the products of element of the matrix , but WHAT IS IT ?


How to start my Serial key from 1 in PostgreSQL

How to start my id column from 1 ?  My tabel is :   id |   origin    | destination | duration ----+-------------+-------------+----------   6 | Paris       | New York    | 540   7 | Tokyo       | Shanghai    | 185   8 | Seoul       | Mexico City | 825   9 | Mexico City | Lima        | 350  10 | Hong Kong   | Shanghai    | 130   Here id is my SERIAL KEY and PRIMARY KEY.  And I am using PostgreSQL.


I have been dealing with this issue since i bought this phone ( Galaxy Note 4 ). I need to change my play store to the US, but I couldn't. I have tried many methods especially, changing my home adress of (google payment or wallet). Many people used to download an app called (Hola and others) ,but i don't prefer to use apps in this way. In google play (Contact us) mentioned that I need to put a payment method related to US. Anyway, I don't have a payment for US.   Is there any way to do it?


Who manned the turrets in the Falcon during the Battle of Endor?

In the final space battle in Return of the Jedi, we see that the Falcon is flown by Lando, with the Sullustian Nien Numb as co-pilot.  However, we never see the turrets fire, nor do we see any mention of them.  Since even the most minor of background characters will have a larger appearance in legends material, is it ever stated who manned the turrets in the Falcon during the Battle of Endor?