In 18.10, When I try to install some packges it shows Some files can not be fetched and for solving this when I try to install synaptic with terminal sudo apt-get install synaptic it returns  avro : Depends: libibus-1.0-dev but it is not going to be installed         Depends: ibus-clutter but it is not going to be installed         Depends: ibus-qt4 but it is not going to be installed  synaptic : Depends: libept1.5.0 but it is not going to be installed             Recommends: libgtk2-perl (>= 1:1.130) but it is not going to be installed             Recommends: rarian-compat but it is not going to be installed E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).   These all. Trying sudo apt --fix-broken install ends up with:  Some files can't be fetched   How this problem can be solved?   The output of sudo apt-get upgrade:  Reading package lists... Done Building dependency tree        Reading state information... Done You might want to run 'apt --fix-broken install' to correct these. The following packages have unmet dependencies:  avro : Depends: libibus-1.0-dev but it is not installed         Depends: ibus-clutter but it is not installed         Depends: ibus-qt4 but it is not installed E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).   The output of sudo apt update:  Err:1 http://security.ubuntu.com/ubuntu cosmic-security InRelease              Temporary failure resolving 'security.ubuntu.com' Err:2 http://us.archive.ubuntu.com/ubuntu cosmic InRelease                     Temporary failure resolving 'us.archive.ubuntu.com' Get:3 http://us.archive.ubuntu.com/ubuntu cosmic-updates InRelease [83.2 kB] Get:4 http://us.archive.ubuntu.com/ubuntu cosmic-backports InRelease [74.6 kB] Fetched 158 kB in 18s (8,857 B/s)   Reading package lists... Done Building dependency tree        Reading state information... Done 169 packages can be upgraded. Run 'apt list --upgradable' to see them. W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/cosmic/InRelease  Temporary failure resolving 'us.archive.ubuntu.com' W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/cosmic-security/InRelease  Temporary failure resolving 'security.ubuntu.com' W: Some index files failed to download. They have been ignored, or old ones used instead.   it's a problem with broken packages fact.

Err http://archive.canonical.com natty InRelease     Err http://security.ubuntu.com oneiric-security InRelease                Err http://extras.ubuntu.com natty InRelease                             Err http://security.ubuntu.com oneiric-security Release.gpg   Temporary failure resolving ‘security.ubuntu.com’ Err http://archive.canonical.com natty Release.gpg   Temporary failure resolving ‘archive.canonical.com’ Err http://extras.ubuntu.com natty Release.gpg   Temporary failure resolving ‘extras.ubuntu.com’ Err http://gb.archive.ubuntu.com oneiric InRelease Err http://gb.archive.ubuntu.com oneiric-updates InRelease Err http://gb.archive.ubuntu.com natty-backports InRelease Err http://gb.archive.ubuntu.com oneiric Release.gpg   Temporary failure resolving ‘gb.archive.ubuntu.com’ Err http://gb.archive.ubuntu.com oneiric-updates Release.gpg   Temporary failure resolving ‘gb.archive.ubuntu.com’ Err http://gb.archive.ubuntu.com natty-backports Release.gpg   Temporary failure resolving ‘gb.archive.ubuntu.com’  Reading package lists... Done W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric/InRelease       W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric-updates/InRelease   W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/natty-backports/InRelease   W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/oneiric-security/InRelease   W: Failed to fetch http://archive.canonical.com/ubuntu/dists/natty/InRelease   W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/natty/InRelease   W: Failed to fetch http://archive.canonical.com/ubuntu/dists/natty/Release.gpg  Temporary failure resolving ‘archive.canonical.com’ W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/oneiric-security/Release.gpg  Temporary failure resolving ‘security.ubuntu.com’ W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/natty/Release.gpg  Temporary failure resolving ‘extras.ubuntu.com’ W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric/Release.gpg  Temporary failure resolving ‘gb.archive.ubuntu.com’ W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric-updates/Release.gpg  Temporary failure resolving ‘gb.archive.ubuntu.com’ W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/natty-backports/Release.gpg  Temporary failure resolving ‘gb.archive.ubuntu.com’ W: Some index files failed to download. They have been ignored, or old ones used instead.   This is what I'm seeing when I try to run sudo apt-get update. I did an update on my instance yesterday and am now experiencing this.


I am playing a cavalier with a lance.The lance description states "A lance deals double damage when used from the back of a charging mount. While mounted, you can wield a lance with one hand."  My GM says that to him the wording means that you only double the lances damage. Example: a 2d6 lance does 4d6. But my Strength bonus and power attack bonus would not be doubled.   So in total the attack would be 2d6(base)+2d6(doubling)+ 8(strength and power attack)for a total 4d6+8 damage roll.  But if I'm reading the rules about multiplying damage correct it states that.  "Sometimes you multiply damage by some factor, such as on a critical hit. Roll the damage (with all modifiers) multiple times and total the results."  This seems to mean that 2d6(base)+2d6(doubling)+8(str and power attack)(doubled) for a total of 4d6+16. Much like that of a x2 critical.  If someone could clarify which reasoning is correct, and why then I would be grateful.

When using a lance while charging on a mount, the rules say that it deals double damage.  My question is, what all damage is doubled? From what I can find, the die roll and strength bonus are doubled, but what about damage such as from a smite ability, or power attack? And how would it work on a crit? Is the damage doubled, then tripled? Or does it work more like vital strike?  I'm building a mounted paladin, and the rules for the lance are kind of vague.  EDIT:  Okay, so, I did find a partial answer.  Under Multiplying Damage, it states that you "Roll the damage (with all modifiers) multiple times and total the results," whenever you multiply damage, and then " When you multiply damage more than once, each multiplier works off the original, unmultiplied damage. So if you are asked to double the damage twice, the end result is three times the normal damage."  So, from what I can tell, on a critical you would just multiply the damage by four (2 for lance, three for lance crit) or five with the Spirited Charge feat.  However, that still makes me wonder about what falls under 'all modifiers.' Working with a fifth level paladin, average stats of 14 across the board (not likely, but not great stats and easier math) that means you could have 2d8+4(str. doubled from lance)+20(smite damage, double for first attack, double again for lance), for a total average of 33. One attack, at fifth level, dealing 33 damage seems a bit high, but not impossibly so.  Now, for my paladin, who's level 10, took spirited charge and power attack, and who has a +2 lance and a strength of 22 after magic items, and who two-hand wields it while charging. That works out to 3d8+27(three times 1 1/2 str. for two-hand wielding)+6(enchantment bonus on weapon)+27(two-hand wield power attack)+60(smite damage on first attack). That comes out to 133 damage, bypassing DR, and not even on a crit, or as min-maxed as I could make it. That seems ridiculous, which is why I'm wondering about it.


Does anyone have experience in using pop-up windows or pop-up metaphor in responsive design? I could imagine this could be challenging.. but perhaps doable?

I am reviewing some website wireframes from a client and have decided to make the new site responsive. I've had pretty good luck so far with responsive theming and design from a few past projects and they look and act really nice across widths / devices.   However this particular wireframe has quite a few modals and hover windows with lots of information in them.   My questions are:   Will this be like trying to fit a square peg in a round hole?  Do we need to perhaps go the m.domain.com route where we query the device and design two separate websites?  Should I advise the client to do away with so many modals and hover windows if we go the Responsive route?   I know these are subjective questions so not really sure if this is appropriate within this type of forum.


I encountered this problem in a textbook: Let $X$ be a countable compact Hausdorff topological space, I was asked to prove that $X$ is always homeomorphic to a (necessarily countable) topological space $Y$ equipped with the order topology of a certain well-order $\leqslant$ on $Y$ (a well-ordering on $Y$ is a total order $\leqslant$ on $Y$ such that every subset of $(Y,\leqslant)$ admits a minimal element, or equivalently, an ordinal). But I had no ideal where to start (I guessed that firstly I had to prove $X$ is first countable, but I failed). Can anyone help me about it? Any useful hint will be appreciated.

I heard at some point (without seeing a proof) that every countable, compact space $X$ is homeomorphic to a countable successor ordinal with the usual order topology. Is this true? Perhaps someone can offer a sketch of the proof or suggest a topology/ordinal text which treats countable spaces in depth. I also wonder if these spaces are metrizable or if they can be embedded into $\mathbb{R}$.  By the way, I'm assuming $X$ is Tychonoff but perhaps this can be reduced to a weaker separation axiom.  Edit: Just to clarify and avoid erroneous future editing,"countable compact space" means "compact space, whose underlying set is countable." This is different from "countably compact space."


See title. Which one is correct?  For reference, in case it matters, RTP is an acronym that stands for Real-time Transport Protocol.

In the following example, is it appropriate to use a or an as the indefinite article, and why?     He ate __ green apple.   I know that in the case of just "apple", it would be "an apple," but I've heard conflicting answers for "green apple," where the noun is separated from the article by an adjective.  Also, which is more appropriate in this case:     He ate  __ enormous Pop-Tart.


How would I go about proving $$ a \equiv b\pmod{m}$$ given $$  a \equiv b\pmod{m^2}  $$ I suspected this was false, so I tried to find a counterexample using a , and there does not appear to be a counterexample for $m$ in (2, 16). What I have tried so far: $$  a \equiv b\pmod{m^2}  $$ $$ a = b + m^2k $$ $$ a - b = m^2k $$ $$ \sqrt{a - b} = \sqrt{m^2k} $$ Which would imply that $\sqrt{a-b} \equiv 0\pmod{m}$ assuming that $k$ is a perfect square. It feels like I'm barking up the wrong tree, however, and I'm not sure where to go from here.

I noticed relation between modulo operation and number which is power of two  Example I have to calculate $ 3431242341 \mod 2^5 $, which is $ 5 $ but it is equivalent to  $ ( 3431242341 \mod 2^9 ) \mod 2^5 $   I tried many examples and it seems to be true in general, and I am not sure if it is a coincidence or true in general that I can use first modulo operation ( greater number) and the result will be the same.


Gauss is reported to have said that if Euler's formula $e^{i \pi} + 1 = 0\,\!$ "was not immediately apparent to a student upon being told it, that student would never be a first-class mathematician."  How is someone supposed to see that this is true?

What does the ratio of the circumference of a circle to its diameter have to do with the base of the natural logarithm and $\sqrt{-1}$?


I need to compare the content of files on 2 different machines. There are around 50 files in the folder on each PC. So far I have done this:  compare (gc \\PC1\d$\Data\Config\*) (gc \\PC2\d$\Data\Config\*) | Out-GridView   and it works fine, but in that way I can't see in which file the difference exist. So I need the filename in the result.

I have two text files and want to find the differences between them using Windows Powershell. Is there something similar to the Unix diff tool available? Or is there another other way I haven't considered?  I've tried compare-object, but get this cryptic output:  PS C:\> compare-object one.txt two.txt  InputObject                                                 SideIndicator -----------                                                 ------------- two.txt                                                     => one.txt                                                     <=


I am making a basic guessing game for my first java test and i have same by an interesting problem. My if statement isn't doing what it is told but when i trace it, the outputs are the same. My Code is... ;   import java.util.Scanner;   public class Game {  public static void main(String[] arg) {     Scanner GetInput = new Scanner(System.in);     try {         String Word;         String Guess;         int attempts = 0;         boolean win = false;              System.out                     .println("Hello, and welcome to the guessing game! This game is very simple; one player will enter a word when");             System.out                     .println("asked, then the next player will need to guess the word Be warned player two, you only have three guesses");             System.out                     .println("Let's get started. Player ONE, please enter you're word: ");             Word = GetInput.next();             System.out                     .println("Okay the word has been entered, now player TWO must guess");              do {                 Guess = null;                 System.out.println("Guess the word: ");                 Guess = GetInput.next();                 System.out.println(Guess + "/" + Word);                 if (Word == Guess) {                     System.out.println("You won!");                     break;                 } else if (Guess != Word) {                     attempts ++;                 }                  if (win == false && attempts == 3) {                         System.out.println("You lose!");                         break;                 }             } while (attempts <= 3);     } finally {         GetInput.close();     } }   }

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


Throughout most of the original Star Wars trilogy, Darth Vader seems to have complete control over the Empire's military hierarchy. It seems his only limitation is needing to report to his Sith Master, the Emperor. For example:   He has full command of the Imperial fleet in The Empire Strikes Back. He even summarily executes Admiral Ozzel and promotes a Captain (Piett) to take his place, without anyone questioning him. (also in The Empire Strikes Back) After Captain Needa loses track of the Millenium Falcon, he honorably confesses to Lord Vader and is nevertheless executed in the same way.      There is one major exception: Grand Moff Tarkin, the commander of the original Death Star, seems to be superior to Darth Vader.   While choking an Imperial officer, Tarkin says "Vader, release him!" and Vader complies. After the Millenium Falcon escapes, we learn that it was let go intentionally. Tarkin says "You're sure the homing device is secure aboard their ship? I'm taking an awful risk, Vader. This had better work." This attitude clearly implies that Tarkin some sort of superiority over Vader. When he discovers the Princess Leia lied about the location of the Rebel Base, Tarkin tells Vader to "Terminate her... immediately." Although the Princess isn't actually executed, Tarkin's instructions are followed at least to the point of her being scheduled for execution. (C3PO says "I'm afraid she's scheduled to be terminated.")     So,   Does Darth Vader have a military rank? If so, what is it? If Vader does have a rank, is it lower than "Grand Moff" (Tarkin's title), or is it just subservient to the "Commander of the Death Star?" Or does Darth Vader simply have a personal respect for Tarkin that leads him to follow his orders by choice rather than by obligation?

Darth Vader was a man of great importance. He carried out highly sensitive missions for the Emperor, ranging from killing Jedi in the  to retrieving the top secret Death Star plans in A New Hope. However, with his appearance and the fact that he doesn't try to hide his affiliation with the Empire, nor that he is a man of importance, he must have had some official role and/or rank within the Empire.   A few other questions have touched on this, for instance , ,  and , but none of them really answered what I was wondering, and some even raised more questions.    Public role  This was my initial question, what was his public role in the Empire? It seems to me that while he may not be present in the capital, or even seen with the Emperor, he should have an official role or some sort of title that the general public can use to identify him with. Calling him 'Lord Vader' could be enough, I guess. The Empire wasn't exactly a transparent ruler, so even if some people (like the rebels) realized that the title of 'Imperial Lord' didn't really cover his actual roles, they wouldn't be able to do anything about it. But did he have an official role in the Empire, and are there any canon/non-canon references that touches on this?  When I thought about this for a while, I realized that the real issue is in fact his...  Rank within the Empire  This is also somewhat related to . The most upvoted comment there suggests that Vader was outside the normal chain of command, which would make sense in A New Hope, but during the assault against the rebel base at Hoth in The Empire Strikes Back, Vader is clearly in charge. Is he a special case when it comes to rank and everyone just sort of obey him, or does the Emperor explicitly tell other officers when Vader is in charge?  If he is outside the chain of command, but still seen as a superior officer and a powerful member of the Emperor's inner circle, how could someone like , Death Star admiral and Chief of the Imperial Navy have the audacity to be disrespectful? I realize that the Force is seen as 'mumbo-jumbo' even by Imperials, but that aside, he must still be regarded as a high-ranking officer. If someone like Motti lacks faith, surely other Imperial officers must feel the same way? Was Motti just stupid enough to let it show?  If a high ranking officer was executing a crucial mission and Vader unexpectedly showed up and wanted to change his plans, would the officer be punished if he refused? Imagine the scenario being played out twice, one where the officer is right, and one where Vader is right. In general, what would be best for the officer to do?    To sum up, what is Vader's official/unofficial role and rank, and how much weight did his words actually carry within the Empire?


I'm on Ubuntu 18.10. Two packages which I'd like to use won't start up. First is pdfsam. Starting from terminal I get the following output:      Exception in thread "main" java.lang.NoClassDefFoundError: javafx/scene/layout/HBox     at java.base/java.lang.ClassLoader.defineClass1(Native Method)     at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1016)     at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:174)     at java.base/jdk.internal.loader.BuiltinClassLoader.defineClass(BuiltinClassLoader.java:802)     at java.base/jdk.internal.loader.BuiltinClassLoader.findClassOnClassPathOrNull(BuiltinClassLoader.java:700)     at java.base/jdk.internal.loader.BuiltinClassLoader.loadClassOrNull(BuiltinClassLoader.java:623)     at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581)     at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)     at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)     at org.pdfsam.community.App.main(App.java:34) Caused by: java.lang.ClassNotFoundException: javafx.scene.layout.HBox     at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583)     at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)     at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)     ... 10 more   Second one is mediathekview. Here the output is as follows:  Fehler: Hauptklasse mediathek.Main kann nicht initialisiert werden Ursache: java.lang.NoClassDefFoundError: com/jidesoft/utils/ThreadCheckingRepaintManager   I had purged and reinstalled both packages and java components, but still fails.  Any ideas please how to fix this?  Kind regards  Stefan

I have the following versions of OpenJDK installed:  java-1.11.0-openjdk-amd64      1101       /usr/lib/jvm/java-1.11.0-openjdk-amd64 java-1.8.0-openjdk-amd64       1081       /usr/lib/jvm/java-1.8.0-openjdk-amd64   I get the following error using PDFsam in Lubuntu 18.04:   INFO   [12:15:47]: Starting PDFsam INFO   [12:15:48]: Transparent windows not supported by the platform INFO   [12:15:48]: Configuring Sejda 3.2.38 INFO   [12:15:48]: Gestarted in 1 second INFO   [12:15:57]: 3.pdf loaded INFO   [12:15:57]: 4.pdf loaded INFO   [12:15:57]: 5.pdf loaded INFO   [12:15:58]: Starting task (org.sejda.impl.sambox.MergeTask@81b1817) execution. WARN   [12:15:59]: New fonts found, font cache will be re-built WARN   [12:15:59]: Building on-disk font cache, this may take a while ERROR  [12:15:59]: Unexpected error java.lang.NoClassDefFoundError: Could not initialize class org.sejda.sambox.pdmodel.font.PDType1Font at org.sejda.impl.sambox.util.FontUtils.<clinit>(FontUtils.java:74) at org.sejda.impl.sambox.component.PDDocumentHandler.close(PDDocumentHandler.java:231) at org.sejda.common.ComponentsUtility.nullSafeClose(ComponentsUtility.java:63) at org.sejda.common.ComponentsUtility.nullSafeCloseQuietly(ComponentsUtility.java:49) at org.sejda.impl.sambox.MergeTask.closeResources(MergeTask.java:232) at org.sejda.impl.sambox.MergeTask.after(MergeTask.java:237) at org.sejda.core.service.DefaultTaskExecutionService.actualExecution(DefaultTaskExecutionService.java:151) at org.sejda.core.service.DefaultTaskExecutionService.execute(DefaultTaskExecutionService.java:71) at org.sejda.core.service.DefaultTaskExecutionService.execute(DefaultTaskExecutionService.java:58) at org.pdfsam.task.TaskExecutionController.lambda$request$0(TaskExecutionController.java:87) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748)


I am beginner in power supply repair. Can anyone completely explain to me how this power supply make PWM without a PWM IC in the primary side?

I want to make a schematic of this board. Can anyone tell me how?


This morning, I was awarded "Nice Answer" in Super User. However, I was viewing a different stack (Puzzling) at the time I noticed the award, and the notification had the PUZZLING badge icon instead of Super User's. When I looked in a different stack (Science Fiction and Fantasy), the badge icon again matched the current stack's badge icon.  Shouldn't this always match the badge icon for the stack in which the badge was awarded? ...as seen in Super User    ...as seen in Puzzling  ...as seen in Science Fiction and Fantasy

It's so cool that the notification reminds you of the colour of badge you've earned. But I am a little puzzled by the symbols:      Is it feasible to use the symbol from the earned site? At the moment it uses the symbol from the site I happen to be on (as you can see by looking to the left of the dropdown in each case.)


If n is a positive integer, the integers a and b are congruent modulo n, i.e. a ≡ b (mod n), if they have the same remainder after division by n. Prove that a ≡ b (mod n) if and only if n|(a − b).

I was reading through a proof of the following proposition:  $$a\equiv b\!\!\pmod{m}\iff (a\bmod m) = (b\bmod m)$$  i.e. $\ a \equiv b \pmod{\!m} $ if and only if a and b leave the same remainder when divided by m   I came across a statement that I didn't quite understand. I boxed my area of confusion below:   I am confused because I expected the inequality to be $ 0 \leq r_1 - r_2 < m$. How did they come to the conclusion that $ -m < r_1 - r_2 < m$  Any input is appreciated.


I'm writing a script to replace a label <p> with a path in some text files (*.prop). However , when I run it I get the following error:  sed: -e expression #1, char 101: unknown option to `s'   My code is the following:  sed -i --  "s/<q>$(echo $destpath | sed -e 's/\\/\\\\/g' -e 's/\//\\\//g' -e 's/&/\\\&/g')/\ResultsTesting/\/g" *.prop   and if I print the echo of my code:  sed -i -- \ s/<q>\/home-students\/rmorales\/testAPK\/air.air.air.com.tabc.gsn-2014_5_11-dex2jar\/ResultsTesting\//g \ myFile.prop   Can someone help me please?

How can I search and replace text that contains / with sed?  I currently use the following command which doesn't work  sed -i "s/queue_directory = /var/spool/postfix-secondary/queue_directory = /var/spool/postfix-$newnumber/g" /etc/postfix-$newnumber/main.cf


My outcomes is binary variable.  I would like to perform logistic regression model to estimate the treatment effect of Xs. However, the follow up time was longer for outcomes=1 and shorter when outcomes=0.  The probability of the outcome can be affected by the follow up time, the longer a subject was followed up, the more chance we observe a outcome=1.  I considered including the follow up time as an offset, like poisson regression model.  Is it reasonable?  Otherwise, how can I control the difference in follow up between the two groups.

Two related questions from me. I have a data frame which contains numbers of patients in one column (range 10 - 17 patients) and 0s and 1s showing whether an incident happened that day. I'm using a binomial model to regress probability of incident on number of patients. However, I would like to adjust for the fact that when there are more patients, there will inevitably be more incidents because the total amount of patient time on the ward is higher on that day.  So I'm using an offset binomial model like this (R-code):  glm(Incident~Numbers, offset=Numbers, family=binomial, data=threatdata)   My questions are:   Is it okay to have exactly the same variables predicting and in the offset? I want to partial out the tonic increase in incident probability and see if there's anything left, essentially. It makes sense to me but I'm a little cautious in case I'm wrong. Is the offset specified correctly? I know that in poisson models it would read  offset=log(Numbers)    I don't know if there's an equivalent here and I can't seem to find any binomial offsets with Google (major problem being that I keep getting negative binomial which of course is no good).


I use the following PHP code to connect to MySQL.  $link = mysql_connect('127.0.0.1', 'root', '123456') or die("wrong user pass mysql"); mysql_select_db('database', $link);   This code is placed in a connection file called connection.php which is included in all PHP scripts that require access to database.  If a hacker gets the URL of connect.php (), is it possible to hack my database? How can I ensure that the PHP connection code does not help the hacker? Or which is the best secure way of connecting to the database?

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


Inside a Nintendo Switch I spotted some traces that take a meandering path to the RAM chips.    What are the benefits of designing it this way, instead of taking the shortest path?

On some PCB designs, specific traces are routed in curious ways. This probably has to do with high frequency design considerations and general signal behavior that I am not familiar with.  Let's take this PCB (somewhere from the web) as an example. It shows part of a PCIe card with SATA routing and DDR2 RAM:    I highlighted 4 areas that qualify as unusual trace layout (from my perspective).   What are those shapes supposed to achieve? How do designers come up with what pattern is required? Another example of wave shaped, antenna like routing. This is fairly rare. But obviously the designer deliberately avoided 45° traces. Why? Curves again and a single "pulse" within the trace. How can this have any significant effect?   So what are the use cases and benefits of this techniques?   I want to be able to take those into consideration when doing future PCB designs.


The description for geas states:     You place a magical command on a creature that you can see within range, forcing it to carry out some service or refrain from some action or course of activity as you decide.   There is a difference of interpretation on this word within my group.  I take it as meaning the creature is literally forced to obey a simple command or refrain from a course of activity.  It cannot voluntarily decide that it will disobey said command.  A friend of mine believes that the target has the option to not follow the command and that the word "forced" is mostly in reference to the fact that if they are not able to carry out the command, they take damage.  He believes that the target has the free will do decide to not carry out the command.    He also used this thread as justification:     Now I think that is an interesting way to view it but there was only one answer and no further discussion, possibly because he was right or there was not much interest at that time.  It seems very odd to me that they used the term "forced" and not "coercively forced" in the spell description if the intent was that the target of the spell has the free will to simply disobey and eat the damage.  I think that if the intent was indeed that the target could voluntarily disobey the command, they would have worded the spell description very differently.  tldr;  If I geas someone and give a command, can they voluntarily decide of their own free will to disobey the command, or are they forced to do the command (and in the event that they are not able to, due to say being restrained somehow, they eat the damage)?     Thank you for your time and effort!

I believe this is the question that a user was trying to get at . Geas states that you cast the spell on a creature, thereby     forcing it to carry out some service or refrain from some action or course of activity as you decide.   The use of the word "forcing" would seem to imply the creature has no choice but to carry out the action you demand of it. However, the spell further describes     While the creature is charmed by you, it takes 5d10 psychic damage each time it acts in a manner directly counter to your instructions, but no more than once each day.   This makes no sense unless it is possible for the creature to disobey you. If the creature has the option to disobey you, then the word "forced" is inaccurate. Should we therefore dismiss the first sentence of this spell as (inaccurate) fluff? Can we safely assume that the creature is not forced at all, but rather coerced into service by the threat of 5d10 psychic damage (which may be an empty threat against creatures with sufficient hit points)?


When installing some apps (some with ppa:) I get a message like: "modifying/updating packet source is not safe and therefore standard turned off. (Own translation from Dutch text). How can I turn it on? I searched everywhere....

I'm using an unsigned repo in Ubuntu 16.04 from Debian multimedia:  deb http://www.deb-multimedia.org jessie main   To install deb-multimedia-keyring, I'm running:  apt-get update && apt-get install deb-multimedia-keyring -y   This gives an error:  W: GPG error: http://www.deb-multimedia.org jessie InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 5C808C2B65558117 E: The repository 'http://www.deb-multimedia.org jessie InRelease' is not signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.


Definition. Let $(G,\ast)$ be any group. Then $G$ will be said to be a topological group if there exists a topology on $G$ such that the map $f:G\times G\to G$ defined by $f(x,y)=xy^{-1}$ for all $(x,y)\in G\times G$ is continuous.   Now observe that in this definition it is important to note that we first have a group and then the topology which makes $f$ cotinuous. In other words, we impose topological stricture on a group.  My question   Is it possible to impose group structure on a topological space? I don't think that it is possible always. So my question is, if $(X,\tau)$ be a topological space then under which condition(s) does there exists a binary operation $\ast:X\times X\to X$ such that $(X,\ast)$ is a group? If there is any related research in mathematics literature then can you please let me know about some of those?     It has been pointed out (see below) that this question is a duplicate of . However, I don't think that they are for the reason as explained in . It is also not clear to me that imposing a group structure on a topological space (if it's possible of course) is expected to result in a topological group.

Let $X$ be a non-empty set. It is known that we can give a group structure on $X$. Now let $X$ be a non-empty topological space. Then can we give a group structure on $X$ so that it becomes a topological group w.r.t. its original topology ?


Hi, I just love this kind of design and I wanna know if exist specific name for this.

What is the name for these type of images? I love these kind of graphics and it's so flat which totally matches my current product development.      Do we have a name for it? A name will make it easier to search for examples and how to's.


Is there a systematic way of solving $x^2-x=0 \pmod{10000}$?  Obviously, since we are dealing with modulo $10000$, this is much more complicated as it is not a prime number. I should also address that I am not trying to find all the solutions but I wanted if there is an algorithm-like way of seeking some solutions.  I realise that $0$ and $1$ are trivially solutions and any other solutions must have more than $3$ digits. I also thought about the zero-divisors of this ring but there are too many zero-divisors. Are there more slick way of doing this problem?

I need the idempotent elements of $Z_{900}$ $2^2\cdot 3^2\cdot 5^2=900$ Of course there's $$0 \pmod 4 \\ 0 \pmod 9 \\ 0 \pmod {25} \\ $$ and $$ 1 \pmod 4 \\ 1 \pmod 9 \\ 1 \pmod {25} \\ $$ I found the answers by making a C++ program to test all numbers, but I don't know how to quick solve on paper. This is the output of the program $(0, 0, 0) \rightarrow 0 \\ (1, 1, 1) \rightarrow 1 \\ (0, 0, 1) \rightarrow 576 \\ (0, 1, 0) \rightarrow 100 \\ (1, 0, 0) \rightarrow 225 \\ (1, 1, 0) \rightarrow 325 \\ (0, 1, 1) \rightarrow 676 \\ (1, 0, 1) \rightarrow 801 \\$


Will the swap partition be utilized to become part of an ext4 filesystem? If not, how will the swap space be utilized?

I was wondering if it's safe to upgrade Maverick Meerkat to Natty (I believe I'm fully aware of the bugginess of Natty at the moment). The only thing that's of concern is altering of other partitions during the install.   Will it wipe any partitions out?


A valid phone number is 10 digits, delimited by a dash, and may contain an optional 1-6 digit extension in the format of " x 123456" or " x 123". The following examples would be valid numbers.  123-456-7890 123-456-7890 x 123 123-456-7890 x 1234  The following RegEx works for a 10 digit phone number: /[0-9]{3}-[0-9]{3}-[0-9]{4}/, however when I attempted to add the optional extension like /[0-9]{3}-[0-9]{3}-[0-9]{4}( x [0-9]{1,6})?/ it broke.  Does anyone know what's wrong?

I'm trying to put together a comprehensive regex to validate phone numbers. Ideally it would handle international formats, but it must handle US formats, including the following:   1-234-567-8901 1-234-567-8901 x1234 1-234-567-8901 ext1234 1 (234) 567-8901 1.234.567.8901 1/234/567/8901 12345678901   I'll answer with my current attempt, but I'm hoping somebody has something better and/or more elegant.


There were a few astronauts. Possibly 3, they went to space I think on a rescue mission of another crew. While in space, they saw the bodies of the other crew floating in space. They managed to fish one in that was still alive. But later it turned to attacked the crew. But I think they managed to overcome it.   Later this crew landed on a planet. On this planet, there was this giant one eye alien with long legs that shot out death ray. They looked kinda like War of the World aliens. One crew was zapped and disintegrated.   Finally, one crew sacrificed himself by walking into this large white sphere like object. As he walked in, he became a skeleton and the sphere was destroyed. I think the remaining one crew managed to escape.

I need the name of an early sci-fi movie, 1950s or early 1960s. I'd call it a C-movie. It was a Mars landing, in a spaceship that looked basically like a coffee can. The seats in the ship were low-backed regular chairs. The elevator taking the crew to the surface was the slowest elevator ever seen. On the surface, they discovered a Mars monster which looked like a giant tin-foil ball spray-painted with lighting effects to make it spooky. I think there were only about 4 crew members. It was a wonderfully awful movie, lots of fun. I'd like to see it again and share it with friends.


I have the follwing code in PHP:  if(is_numeric($first_name[0]) === true){    //Do something }   How would I be able to do the same check using JavaScript?  I also would like to get a PHP script to check if there is a number in $first_name at all, as I don't want the user to add a number in their first or last names please?

What's the cleanest, most effective way to validate decimal numbers in JavaScript?  Bonus points for:   Clarity. Solution should be clean and simple. Cross-platform.   Test cases:  01. IsNumeric('-1')      => true 02. IsNumeric('-1.5')    => true 03. IsNumeric('0')       => true 04. IsNumeric('0.42')    => true 05. IsNumeric('.42')     => true 06. IsNumeric('99,999')  => false 07. IsNumeric('0x89f')   => false 08. IsNumeric('#abcdef') => false 09. IsNumeric('1.2.3')   => false 10. IsNumeric('')        => false 11. IsNumeric('blah')    => false


I have some components here to make an SMPS from mains for a CV/CC power supply for my workshop, and I decided to add a linear post-regulator to smooth the output. To avoid big heatsinks I wanted the SMPS voltage to follow the post-regulator voltage when I adjust it, and I've found a possible solution from . However my simulations showed better results while using an OpAmp (image below). As you can see, I set up the comparator of the SMPS in a way that the output voltage of the post-regulator will determine the output voltage of the SMPS (keeping it always 5V more then the post-regulator output for example, precision is not a problem). The circuit works fine on simulation, however I wanted to know if ripple, noises or imperfections of hardware that doesn't exist in my simulation might make this a bad idea, and what filters should I study to put on the output of this OpAmp (if any) to avoid any problems with this "follower" circuit before I buy the components I need. I have another comparator not shown in the image that is doing the current sensing.

I'm trying to find a way of building a new power supply for my workshop, in order to keep it small and not so hot I will be using a spare xformer to step down mains to 24v and then a variable buck converter to adjust it (and CC mode, displays and blinky stuff).   I thought it would be a good idea to use a linear regulator on the output stage to smooth things out, but I can't seem to think of a control scheme that allows me to change the voltage using only one potentiometer. The buck stage is this topology but with a external PNP transistor.(It has already been prototyped, it works alright, I know the mc34063A is old)   The only idea I got that ""works"" is using the buck converter output as a reference for a linear regulator (IC or discrete parts), but using a SMPS output as reference for anything is a bad idea, due to the amount of noise and fluctuations.   This is the sort of output stage I can and have built (or bought) over time. Just a big discrete regulator.  In short: How to control a MC34063A step down (buck) converter so it follows the output stage +1-3 V of headroom.


Let's have unknown disk drive uncompressed raw image (created for example by dd if=/dev/sda of=image) in single file. If we knew the disk layout, we could mount particular partitions from the file as the loop devices via skipping some offsets. Let's suppose we don't know the layout. Can we somehow "mount" the whole disk drive image, which process would create virtual block devices according to the disk layout? For example having 2 partitions in the image would result in creating 3 devices (/dev/sdx, /dev/sdx1, /dev/sdx2). We could then mount such devices as usual.

I have an image of the entire disk created using dd. The disk structure follows:  kent@cow:~$ sudo fdisk -l  Disk /dev/sda: 750.1 GB, 750156374016 bytes 255 heads, 63 sectors/track, 91201 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0x000b8508     Device Boot      Start         End      Blocks   Id  System /dev/sda1   *           5       90872   729929303+  83  Linux /dev/sda2           90873       91201     2642692+   5  Extended /dev/sda5           90873       91201     2642661   82  Linux swap / Solaris   The image was created using:  dd if=/dev/sda of=image750.img   How would I, if it is possible, mount /dev/sda1 from the image so that I'm able to read the contents?  It's not an option to clone the HDD again, I know how to do it if I had only cloned the single partition by itself. I hope it's still possible with the current image.


I'm beginner using Blender 2.91.0. I'm following tutorials and I tried to search "separate" but nothing shows up in obejcet mode.  +Thanks for answer and comments. I was following this tutorial: youtube.com/watch?v=At9qW8ivJ4Q. I found out that separate is only possible in edit mode before asking this question. However on the video at at 1:00:54, it seems that Separate is possible in object mode. Mine still didn't work in object mode, so I was curious about it.

I've just made a set of armor by using a male body mesh model I downloaded and selecting certain faces from the model and duplicating them to create viable armor pieces.   Since the pieces are just duplicated from the same mesh male model, then it's still part of the same object.   How do I separate the armor piece from the model to make the pieces separate?


This is a Problem from Evans PDE 2nd Edition,Chapter 2 Problem 24. (Equipartition of energy). Let $u$ solve the initial-value problem for the wave equation in one dimension: $$\left \{  \begin{array}{ll}   \ u_{ tt}-u_{ xx}=0, \text{ in } \Bbb R\times (0,\infty) \\    \ u=g,u_t=h,\text{ on } \Bbb R\times\{ t=0\}. \end{array} \right.$$ Suppose $g,h$ have compact support. The kinetic energy is $k(t):=\frac{\ 1}{2}$$\int_{-\infty}^{\infty}\ u_t^2(x,t)dx$ and the potential energy is $p(t):=\frac{\ 1}{2}$$\int_{-\infty}^{\infty}\ u_x^2(x,t)dx$. Prove (a) $k(t)+p(t)$ is constant in $t$. (b) $k(t)=p(t)$ for all large enough times $t$.

Let $u$ solve the initial-value problem or the wave equation in one dimension: $$\begin{cases}u_{tt}-u_{xx}=0 & \text{in } \mathbb{R} \times (0,\infty) \\ u = g, u_t = h & \text{on } \mathbb{R} \times \{t=0\}. \end{cases}$$ Suppose $g,h$ have compact support. The kinetic energy is $k(t) := \frac 12 \int_{-\infty}^\infty u_t^2(x,t) \, dx$ and the potential energy is $p(t) := \frac 12 \int_{-\infty}^\infty u_x^2(x,t) \, dx$. Prove (a) $k(t)+p(t)$ is constant in $t$, (b) $k(t)=p(t)$ for all large enough times $t$.  This is Chapter 2, Exercise 24 of PDE Evans, 2nd edition. I am only doing part (a) right now; my work is shown below: Define $$e(t):=k(t)+p(t)=\int_{-\infty}^\infty u_t^2+u_x^2 \, dx.$$ Then $$e'(t)=\frac 12 \int_{-\infty}^\infty 2u_tu_{tt}+2u_{x}u_{xt} \, dx= \int_{-\infty}^\infty u_tu_{tt}+u_{x}u_{xt} \, dx.$$ Now, I want to get $e'(t)=0$ so that $e(t)$ is constant. How can I go about doing this? I do know that I can use $u_{tt}-u_{xx}=0$, if $t > 0$. With $t>0$ into mind, do I have to consider the $t=0$ case separately? Or can I treat both cases together as $t \ge 0$, since $g$ and $h$ have compact support?


Let G be a group with even order. (no binary operation given)  Prove using only the definition of a group that there is $ a\in G$ s.t $a \neq e $ where $a= a^{-1}$  Originally I wanted to say if G is even then order of G =2k for some integer k and somehow show that some element with order k and order 2 must exist. sadly the group isnt nicely defined for me to do this.   Ive been trying to find a contradiction since G is a group if $a \in G$ then $a^{-1} \in G$  since G is finitely ordered the maximum order an element can have is the order of G and $ \forall a $ where $a\in G$ $a^2 \neq e$  EDIT: I'm not sure who thinks this is the same as the linked question but it using many items what i have not been taught nor does it even really answer the stated question the comment below the answer does however.

I am working on the following problem from group theory:     If $G$ is a group of order $2n$, show that the number of elements of $G$ of order $2$ is odd.   That is, for some integer $k$, there are $2k+1$ elements $a$ such that $a \in G,\;\; a*a = e$, where $e$ is the identity element of $G$.


Prove that the function $$f(m,n)=\frac{1}{2}\left(m^2+2 m n+n^2+m+3 n\right)$$ is a bijection between $\mathbb{N}^2$ and $\mathbb{N}$.  The problem arose in a series problem. I have to show that for each couple $(m,n)$ we get a different natural number and that all natural numbers are got applying $f$. Below an example of what happens for $m,n$ from $0$ to $6$ $$ \begin{array}{ccccccc}  0 & 2 & 5 & 9 & 14 & 20 & 27 &\ldots\\  1 & 4 & 8 & 13 & 19 & 26 & 34 &\ldots\\  3 & 7 & 12 & 18 & 25 & 33 & 42 &\ldots\\  6 & 11 & 17 & 24 & 32 & 41 & 51 &\ldots\\  10 & 16 & 23 & 31 & 40 & 50 & 61 &\ldots\\  15 & 22 & 30 & 39 & 49 & 60 & 72 &\ldots\\  21 & 29 & 38 & 48 & 59 & 71 & 84 &\ldots\\ \ldots\\ \end{array} $$

How would you prove the  bijective? I only know how to prove a bijection by showing (1) If $f(x) = f(y)$, then $x=y$ and (2) There exists an $x$ such that $f(x) = y$  How would you show that for a function like the Cantor pairing function?


I was trying to understand why a stable orbit of a hydrogen atom has to satisfy that the orbit length must be a multiple of de Broglie wavelength.  I have seen some related questions like .  But the answers seemed not very clear to me. "For the system to be stable, that is, the electron shouldn't cancell itself out". I agree with "shouldn't cancel out" But I didn't understand why only an n*π would be chosen.   I've known it should be a condition for "standing wave", but a standing wave is not necessarily n*π, is it? I'd like to know in detail about why it's stable. Moreover, what if it's an ellipse orbit? Thank you all in advance!

So, I was reading Atom: Journey Across The Subatomic Cosmos by Isaac Asimov in order to better understand quantum mechanics when I came across this sentence:      The electron couldn't spiral into the proton because it couldn't take up an orbit with a length less than a single wave.    I was wondering why that is? Why can't an electron not have non-whole number wavelengths in atomic energy levels?


I am trying to fetch task and sub-task from a list via the rest api and display the in a page.  here is my html:

Get Site List via REST API Call
    here is my call:  function getListData() {      var fullUrl = "siteurl/_api/web/lists/getbytitle('Tasks')/items?$select=*,ParentID/Id&$expand=ParentID";      $.ajax({         url: fullUrl,         type: "GET",         headers: {             "accept": "application/json;odata=verbose",         "content-type": "application/json;odata=verbose",         },         success: onQuerySucceeded,         error: onQueryFailed     }); }  function onQuerySucceeded(data) {     var mainTasks = [];     var subTasks = [];     for(var i = 0; i < data.length; i++) {         if(data[i].ParentID.Id) {             subTasks.push(data[i]);         } else {             mainTasks.push(data[i]);        }     }      $("#divTaskItems").html(mainTasks);       $("#divSubTaskItems").html(subTasks); }  function onQueryFailed() {     console.log('Error!'); }   The only thing that displays on my page is the  tag.  Thanks in advance.

Want to display Task and sub-task using the  rest api jquery. My query string displays task and sub-task as individual unrelated task.


I recently sold my NES Legend of Zelda that I bought around 1989 for my kids. The buyer thinks it's a fake because it does not have any batch/quality control stamping on the back.  Nothing else about the game looks fake.  Can anyone definitively say that all Zelda NES games produced had a stamp?  And were there even fake copies around in 1989?  I called Nintendo for help, the person I chatted with wasn't even aware that Nintendo's seal was round instead of the oval the first few years. Appreciate any thoughts

The other day, i plugged in a copy of Mortal Kombat 3, and the console I was using was one of the new dual consoles(nes+snes games). I got a message at the start that said something about pirated games. How can I know if I bought say Earthbound at a Vintage Stock or Ebay is going to be authentic? Some of these older games are fairly expensive.


A weird question below.  Suppose you did a 10 fold cross-validation to show that a model is an unbiased estimator. And the results of the cross-validation also shows that training the model longer will improve its prediction accuracy. However you do not have the computational capacity to keep training all 10 folds. Is it scientifically correct to refit the model with all the data and continue training to obtain the final model. Will the results from the 10-fold cv be invalid? Would you still be able to conclude that the model is unbiased?  cheers

I am wondering how to choose a predictive model after doing K-fold cross-validation.   This may be awkwardly phrased, so let me explain in more detail: whenever I run K-fold cross-validation, I use K subsets of the training data, and end up with K different models.   I would like to know how to pick one of the K models, so that I can present it to someone and say "this is the best model that we can produce."   Is it OK to pick any one of the K models? Or is there some kind of best practice that is involved, such as picking the model that achieves the median test error?


I am using Ubuntu and have chromium installed in it. For every video on you tube it is giving me an error that the video is not available. I had installed flash player too but it is not working. I don't know why it is happening.  On clicking to learn more link, the help is answering like the video is removed or currently unavailable which is not possible as it could not be the case for every video on you tube.

Chromium on Ubuntu 12.04. Youtube says:     This video is currently unavailable   I don't know why but this is the case for some videos, but not all. Well, most videos. And I don't know what's wrong.  Anyone help?


I just logged in- and..    I am worried. Is it okay? Just to make sure, I don't use and never wished to use and never used a hacking engine.

I was just awarded +100 reputation on all of my Stack Exchange accounts.  What is this bonus for? It simply says "Association Bonus" on my reputation overview.  Also:   What privileges does the association bonus grant users? Can I lose the association bonus? Does it make my reputation 101 everywhere? Can I earn the association bonus on sites I haven't joined yet? Does it matter which site I earn the 200 reputation on? Will I get an association bonus every time my reputation on a site crosses 200 points? Does the association bonus allow me to answer protected questions? Does the association bonus count towards the reputation cap? Can I get the association bonus if I only have a profile on one site? What else is there to know about the association bonus?


Not very well versed with Ubuntu. I got this message when I tried to get some updates:   The upgrade needs a total of 31.9 M free space on disk '/boot'.  Please free at least an additional 27.6 M of disk space on '/boot'.  Empty your trash and remove temporary packages of former installations using 'sudo apt-get clean'.   When I'm trying to run 'sudo apt-get clean', it says command not found. How do I remove temp packages?

I try to do do-release-upgrade but then I get:       Not enough free disk space      The upgrade has aborted. The upgrade needs a total of 25.7 M free   space on disk '/boot'. Please free at least an additional 25.7 M of   disk space on '/boot'. Empty your trash and remove temporary packages   of former installations using 'sudo apt-get clean'.   Output of df:                      237251272 214797108  10402504  96% / udev                    488120         4    488116   1% /dev tmpfs                   198676       668    198008   1% /run none                      5120         0      5120   0% /run/lock none                    496684         0    496684   0% /run/shm /dev/sda1               233191    225867         0 100% /boot   How come there is no space left on boot? Here's the output of ls -as /boot:  total 221839     4 .     4 ..   645 abi-2.6.32-34-generic-pae   698 abi-2.6.35-30-generic-pae   727 abi-2.6.38-12-generic-pae   727 abi-3.0.0-12-generic-pae   727 abi-3.0.0-13-generic-pae   727 abi-3.0.0-14-generic-pae   727 abi-3.0.0-15-generic-pae   727 abi-3.0.0-16-generic-pae   727 abi-3.0.0-17-generic-pae   727 abi-3.0.0-19-generic-pae   761 abi-3.0.0-20-generic-pae   115 config-2.6.32-34-generic-pae   128 config-2.6.35-30-generic-pae   136 config-2.6.38-12-generic-pae   140 config-3.0.0-12-generic-pae   140 config-3.0.0-13-generic-pae   140 config-3.0.0-14-generic-pae   140 config-3.0.0-15-generic-pae   140 config-3.0.0-16-generic-pae   140 config-3.0.0-17-generic-pae   140 config-3.0.0-19-generic-pae   140 config-3.0.0-20-generic-pae     5 grub 10773 initrd.img-2.6.32-34-generic-pae 13619 initrd.img-2.6.35-30-generic-pae 15365 initrd.img-2.6.38-12-generic-pae 16481 initrd.img-3.0.0-12-generic-pae 16487 initrd.img-3.0.0-13-generic-pae 16501 initrd.img-3.0.0-14-generic-pae 16476 initrd.img-3.0.0-15-generic-pae 16481 initrd.img-3.0.0-16-generic-pae 16478 initrd.img-3.0.0-17-generic-pae    12 lost+found   174 memtest86+.bin   176 memtest86+_multiboot.bin  1700 System.map-2.6.32-34-generic-pae  1841 System.map-2.6.35-30-generic-pae  2115 System.map-2.6.38-12-generic-pae  2141 System.map-3.0.0-12-generic-pae  2141 System.map-3.0.0-13-generic-pae  2143 System.map-3.0.0-14-generic-pae  2146 System.map-3.0.0-15-generic-pae  2147 System.map-3.0.0-16-generic-pae  2147 System.map-3.0.0-17-generic-pae  2148 System.map-3.0.0-19-generic-pae  2149 System.map-3.0.0-20-generic-pae     2 vmcoreinfo-2.6.32-34-generic-pae     2 vmcoreinfo-2.6.35-30-generic-pae     2 vmcoreinfo-2.6.38-12-generic-pae     2 vmcoreinfo-3.0.0-12-generic-pae     2 vmcoreinfo-3.0.0-13-generic-pae     2 vmcoreinfo-3.0.0-14-generic-pae     2 vmcoreinfo-3.0.0-15-generic-pae     2 vmcoreinfo-3.0.0-16-generic-pae     2 vmcoreinfo-3.0.0-17-generic-pae     2 vmcoreinfo-3.0.0-19-generic-pae     2 vmcoreinfo-3.0.0-20-generic-pae  4092 vmlinuz-2.6.32-34-generic-pae  4347 vmlinuz-2.6.35-30-generic-pae  4567 vmlinuz-2.6.38-12-generic-pae  4675 vmlinuz-3.0.0-12-generic-pae  4676 vmlinuz-3.0.0-13-generic-pae  4681 vmlinuz-3.0.0-14-generic-pae  4698 vmlinuz-3.0.0-15-generic-pae  4700 vmlinuz-3.0.0-16-generic-pae  4700 vmlinuz-3.0.0-17-generic-pae  4703 vmlinuz-3.0.0-19-generic-pae  4705 vmlinuz-3.0.0-20-generic-pae   Output of uname -a:   Linux kitsch 3.0.0-17-generic-pae #30-Ubuntu SMP Thu Mar 8 17:53:35 UTC 2012 i686 i686 i386 GNU/Linux


I want to find all integers $a$ and $b$ that satisfy $a^b=b^a$, where $0<a<b$. By guessing I found that $a=2$ and $b=4$ is a solution. I'm not sure whether it is the only solution, though intuitively I think it is. How can I prove this? Thank you!

We know that $2^4 = 4^2$ and $(-2)^{-4} = (-4)^{-2}$. Is there another pair of integers $x, y$ ($x\neq y$) which satisfies the equality $x^y = y^x$?


I was using the Transparent BSDF node on a mesh, but even when I set it to full transparency there are some strange black areas that refuse to disappear. They change somewhat with the camera angle.      How do I get rid of these artifacts? I'm using Blender v2.79b.

Using v2.73, cycles and a very simple scene: an array of cubes, no big deal.   If I set the shader's material to transparent, the cubes in the foreground do become transparent but those far away in the back do not disappear completely and this strange dark things appear (visible in rendered mode and in final renders)    I've played with the clipping distance on the viewport and camera, but I can't figure out how to make those ghosts go away...


How do you get a USB webcam’s serial number from the Linux command line?  I have multiple USB webcams connected to an Ubuntu machine. They all show up as /dev/video0, /dev/video1, /dev/video2, etc, but I can't seem to find any way to programmatically tell which is which. Several of the cameras are the same model, so just getting a model name isn't enough.  Note, I'm not asking how to use lsusb. Yes, I know you can use lsusb or libusb to get device serial number, product ID, manufacturer name, etc. But as far as I can tell, nothing shown by lsusb can be cross-referenced with a /dev/video* path.  e.g. If someone plugs in two identical webcams and they show up as /dev/video1 and /dev/video2 and then unplugs them and replugs them into completely different ports, so that /dev/video2 becomes /dev/video3 and /dev/video1 becomes /dev/video4, I can immediately know that the current /dev/video3 "used to be" /dev/video2.  The only similar questions I've found only suggest hacks like unplugging and and replugging it while scanning dmesg. I'm looking for a pure-programmatic solution that requires no hardware manipulation to identify the webcams.

I have five USB cameras, same brand, same model (Canyon CNR-FWC120H). They are used to monitor different scenes 24/7. I need to somehow identify which camera is which from the Linux (Debian) console or programmatically (any language).      I’ve tried looking at the output of lsusb -vvv, there is a field iSerial which should be different for each camera but unfortunately this manufacturer decided not to bother and all cameras have the same serial at that place: 200901010001  Is there any other way I could identify which camera is which independently of USB ports to which they are connected because unfortunately in my specific scenario I can not rely on the fact that the same camera will always be connected to the same port.  UPDATE After some discussion in the comments I realize this is mission impossible. So forget the last paragraph or if you do have some ingenious idea, please, you are welcome to present it. I’m now interested if I could identify which USB port the device is connected to; I use the built-in USB ports on the motherboard and additional PCI USB controller cards to accommodate the cameras with enough bandwidth. I would need to uniquely identify the port, and the port number/identification should not change if for example the machine reboots and for some reason the USB controllers get initialized in different order. Is that possible?  UPDATE 2 I see in my logs for one of the cameras the following info:  [Wed Apr 30 18:35:02 2014] uvcvideo: Found UVC 1.00 device FULL HD 1080P Webcam (0bda:58b0) [Wed Apr 30 18:35:02 2014] input: FULL HD 1080P Webcam as /devices/pci0000:00/0000:00:01.0/0000:01:00.0/usb3/3-2/3-2:1.0/input/input4   Using that, I’ve called this command:  udevadm info --query=all --path=/devices/pci0000:00/0000:00:01.0/0000:01:00.0/usb3/3-2/3-2:1.0/input/input4   And got this:  P: /devices/pci0000:00/0000:00:01.0/0000:01:00.0/usb3/3-2/3-2:1.0/input/input4 E: DEVPATH=/devices/pci0000:00/0000:00:01.0/0000:01:00.0/usb3/3-2/3-2:1.0/input/input4 E: EV=3 E: ID_BUS=usb E: ID_INPUT=1 E: ID_INPUT_KEY=1 E: ID_MODEL=FULL_HD_1080P_Webcam E: ID_MODEL_ENC=FULL\x20HD\x201080P\x20Webcam E: ID_MODEL_ID=58b0 E: ID_PATH=pci-0000:01:00.0-usb-0:2:1.0 E: ID_PATH_TAG=pci-0000_01_00_0-usb-0_2_1_0 E: ID_REVISION=5801 E: ID_SERIAL=Generic_FULL_HD_1080P_Webcam_200901010001 E: ID_SERIAL_SHORT=200901010001 E: ID_TYPE=video E: ID_USB_DRIVER=uvcvideo E: ID_USB_INTERFACES=:0e0100:0e0200:010100:010200: E: ID_USB_INTERFACE_NUM=00 E: ID_VENDOR=Generic E: ID_VENDOR_ENC=Generic E: ID_VENDOR_ID=0bda E: KEY=100000 0 0 0 E: MODALIAS=input:b0003v0BDAp58B0e5801-e0,1,kD4,ramlsfw E: NAME="FULL HD 1080P Webcam" E: PHYS="usb-0000:01:00.0-2/button" E: PRODUCT=3/bda/58b0/5801 E: PROP=0 E: SUBSYSTEM=input E: UDEV_LOG=3 E: USEC_INITIALIZED=41090223   The things that differ between the cameras are DEVPATH, ID_PATH, ID_PATH_TAG, PHYS and (most interesting) USEC_INITIALIZED. Now the first four elements are probably related to the USB port, but the last one USEC_INITIALIZED looks like some sort of serial number. I can’t find any info about what it actually represents. Does anyone know anything about it? I thought that it is maybe the time in micro seconds when the camera initialized but the camera that initialized after this one has USEC_INITIALIZED=17919751, and then the one after that USEC_INITIALIZED=25609278 so it seems rather random. I’ll try to reboot the system and see, but I need to wait for a convenient time to do that.   And if anyone is wondering why I don’t just try reconnecting a camera and see if that remains the same. The answer is that I’m operating this PC remotely, and I’m investigating all this to prepare the system to be fully autonomous for any potential event in the future. Which for example might include disconnecting the cameras from USB ports.


Let B be a countable set, and let A be an uncountable set. Prove that A-B is uncountable

Problem statement  Prove that if $A$ is an uncountable set and $B$ is a countable set, then $A\setminus B$ must be uncountable.  What I think  The statement does not mention $A$ and $B$ relationship. I think there are two possibilities:   If $A \cap B = \emptyset $, then $A\setminus B$ is trivially uncountable If $A \cap B = B$, then $B \subset A$ and as a bijection can not be made between $A\setminus B$ and $\mathbb{N}$, $A\setminus B$ is uncountable.   And there is where I'm stuck. How can I prove that a bijecton can't be made?  TIA.


Let $X=\{x\mid x=1+1/2+1/3+1/4+\cdots+1/n\}$ where $n\in\Bbb N$. Find $X\cap \Bbb N$.   What I can figure out is to use a general formula and then apply divisibility theorems to solve this, but I suppose there is no way to find the sum of a harmonic series. Can anybody give me a hint as to what other methods can be used to solve this question?

If $n>1$ is an integer, then $\sum \limits_{k=1}^n \frac1k$ is not an integer.  If you know , then you know there must be a prime $p$ between $n/2$ and $n$, so $\frac 1p$ appears in the sum, but $\frac{1}{2p}$ does not. Aside from $\frac 1p$, every other term $\frac 1k$ has $k$ divisible only by primes smaller than $p$. We can combine all those terms to get $\sum_{k=1}^n\frac 1k = \frac 1p + \frac ab$, where $b$ is not divisible by $p$. If this were an integer, then (multiplying by $b$) $\frac bp +a$ would also be an integer, which it isn't since $b$ isn't divisible by $p$.  Does anybody know an elementary proof of this which doesn't rely on Bertrand's Postulate? For a while, I was convinced I'd seen one, but now I'm starting to suspect whatever argument I saw was wrong.


I am using ArcGIS 10 with ArcEditor license. I have a 10 year composite of month-to-month temperature values for 17 weather stations. That makes 120 months. I have to select each and every month separately and create a layer out of that selection. Is there an easy way to do that so that I can avoid having to make the repetitive 120 selections?

I would like to split a single shapefile into multiple shapefiles by using unique values for one attribute/field to select features for each value out into a new feature class.   I found ET Geowizard to do this but it's not free.   In  I found a tool named "SplitLayerByAttributes" but it does not work in ArcMap . (see comments below, this was an old version which has been updated.  The new version can be found at    )  Do you know of any tools or solution to split by attribute in the way described above?


I have a class function int ComputerClass::getGuess() that every time it is called should produce a randomized number.  In my main function I created 2 functions of the class ComputerClass Computer1,Computer2 and called the class function, however it returns the same number for each call:  cout << Computer1.getGuess()<<endl; cout << Computer2.getGuess()<<endl;   Below is the class member function   int ComputerClass::getGuess() {     //Generate randomn number     srand(time(NULL));     generatednumber = rand() % 100 + 1;      //return computers randomly generated #     cout <<"--(Computer)Please enter a guess between 1-100: "<<      generatednumber<<endl;      return generatednumber; }   I'm assuming my issue is the seed value, however I don't know how to set it up so that makes the number random every time it is called.

I need a 'good' way to initialize the pseudo-random number generator in C++. I've found  that states:     In order to generate random-like   numbers, srand is usually initialized   to some distinctive value, like those   related with the execution time. For   example, the value returned by the   function time (declared in header   ctime) is different each second, which   is distinctive enough for most   randoming needs.   Unixtime isn't distinctive enough for my application. What's a better way to initialize this? Bonus points if it's portable, but the code will primarily be running on Linux hosts.  I was thinking of doing some pid/unixtime math to get an int, or possibly reading data from /dev/urandom.  Thanks!  EDIT  Yes, I am actually starting my application multiple times a second and I've run into collisions.


I wonder if there is a word or a few words or phases that describe a person very often:    judge a person based on one or two tiny details or critise harshly over small mistakes that one made (probably by accident) ignore the reason behind the details or the mistakes often use exaggeration and have twisted logic   For example, one employee has always been punctual but 5 minutes late for one meeting because he was in a car accident. The boss forgot about all the times that the employee was on time and criticized him as 'worthless', 'looser' (exagerated criticising) and refused to listen to any explanation.   Being late was the fact, but the boss is ____ to judge the employee as a person based on this one incidence.   Thanks for the replies, I think these two are the closest:  'judgmental' (too quick to criticise people); 'nitpicking' (find faults in small details)  EDIT: ---- I found that this question is marked as 'duplicate' as 'A single word for someone who is not pleased no matter how hard you try'. The answer to that question is 'implacable', I realize that it does fit well in the 'boss' example, maybe because bosses are often described as pure evil, it is easy to link, but what I was searching for wasn't completely about the evil doing, more about deriving the (often wrong) judgement on your entire personality from one small incidence.  Example:   You were having dinner with some friends. There was tea, you took one sip without noticing the steam, found out that it was too hot, by instinct, you swallowed it with your mouth slightly open, which made a noise that sounded like you slurped (detail/mistake). When you went back, your friends made jokes of you and told everyone that you slurp when you drink. They pointed out that it was because you were born in a small village, so you are 'barbarian', you must slurp a lot before you came to the city (judgement). The fact is that you were born in a village but slurping has nothing to do with it (friends have no logic). The incidence at the dinner was because the tea was hot. Your friends know the tea was hot but still make fun of you (ignore the reason) about your (background, status, family etc.).  These friends may talk to you, help you, but they still think you as 'barbarian' because of one incidence. They also laugh with you at others (in the same way) when they find a new target, so you want to say to your friends:  "Hey, you are ____ / it is ____ to treat people in this way, please stop doing that."

I'm looking for a word that means     someone (especially a boss) who is not pleased (with your work, attitude etc.) no matter how hard you try.


I got the filename and path (gallery/thumbnail) where thumbnail can be png,jpg or mp4. it will always have the name "thumbnail" and i will always know the path.  How to find out what format the file is with php?  Edit.  I do not have the full file name (gallery/thumbnail.png) I only go the path without the extension (gallery/thumbnail.)  $fileName = "gallery/thumbnail.png' //file could be this $fileName = "gallery/thumbnail.jpg"; //or this $fileName = "gallery/thumbnail."; //but i only know this

This is a question you can read everywhere on the web with various answers:  $ext = end(explode('.', $filename)); $ext = substr(strrchr($filename, '.'), 1); $ext = substr($filename, strrpos($filename, '.') + 1); $ext = preg_replace('/^.*\.([^.]+)$/D', '$1', $filename);  $exts = split("[/\\.]", $filename); $n    = count($exts)-1; $ext  = $exts[$n];   etc.  However, there is always "the best way" and it should be on Stack Overflow.


We know that magnetic field lines tend to form a closed loop! we also know that light is a electromagnetic wave so it has an associated magnetic field with it, at any instant $t$ the $ B = B_{0} \sin (\omega t - kx + \phi) $, I cannot find any way how this field might follow the above property!  if it doesn't, then please explain the reason and if it does or I am asking something trivial, be kind enough to answer

It might sound naive but the question is:  In an Electromagnetic wave in  a vacuum the electric and magnetic fields are vibrating but what are the source and drain of these fields?  An electric field must start from a charge and end or be in a circular fashion due to varying magnetic field and in a similarly way, magnetic fields must form a closed loop.  Please explain  this idea?  if magnetic fields are to be in closed loop always then the oscillating fields of a em waves must be too.  So what is the shape of fields in general near a em wave?


What is the formula and result for working out the interest rate required for making £38106 into £73036 in 20 years?  (As if you put £38106 into a bank account and left it for 20 years, never taking anything out or putting anything else in.)

Assume the PV=100, FV=150, yearly IR=X, number of period = 60 (5 years of interest and compounding is monthly basis)  Therefore:  FV = PV * (1 + X / 12)^60    How can I calculate X easily?   Technically I can use (root(FV/PV))-1)*12, where root(N) is the 60th root of N. But is there any existing function I can use such as PV and FV?


I'm trying to make Drupal admin interface easier for non-technical users. Actually, I'm trying to "create" a new interface for these kind of users. I'm using , ,  etc. to make a better admin interface experience without scaring them with a complex structure. Easily;  edit, enable/disable blocks, edit-rearrange main menu, manage users, manage contents, manage files, images etc. uploaded via Drupal interface,  What should be done to increase user experience of this admin interface? Is there any must-use module you suggest?

Basically Drupal is bit complicated for normal clients. Drupal 7 is better but still its not that user friendly for clients especially when comes to admin content or taxonomy!  Is there any module or themes which designed the client in mind? I found  and  very helpful :) Any other to simplify admin section?


How can I get the disk-drive hardware ID in C# ?  I tried System.Management, but I think this is only for processor ID.  I need the hardware ID that we find in cmd by typing wmic diskdrive get serialnumber!

I'm looking to get data such as Size/Capacity, Serial No, Model No, Heads Sectors, Manufacturer and possibly SMART data.


I have  many keyboard shortcuts in my pc (windows 7 , 64 bit) .  I set those keyboard shortcuts  to the "shortcut" of the program/script.  For example , if I want to run chrome via ctrlshiftalt+d then I go to     Question  Since I have many shortcuts like these , I forgot some.  Is there any way to see all current assigned keyboard shortcuts?

Given a hotkey, how can I find which program owns it?


I need to prove that for any positive integers $a$, $b$, $c$ and $k$ the statement $(a^b\bmod k)^c \bmod k = \left(a^b\right)^c\bmod k$ is always correct (I think it is). I know very little of modular arithmetic so I please be gentle with me.

I am working on a problem I am pretty close to solving but I can't figure out the last part. I used some algebraic manipluation to break the problem down. The problem is:     Show that the following congruence is true      a^b = ((a mod n)^b) (mod n)      for any positive integers a, b, and n.      Hint: Number a can be written as a = q*n + r, where q = floor brackets a/n, and r = a mod n.   My attempt it:     (q*n +r)^b = ((a mod n)^b) * (mod n)      (q*n)^b + (a mod n)^b = ((a mod n) ^b) * (mod n)      (a)^b -(r)^b = ((a mod n) ^b) * (mod n)      (a)^b = modn  ----> divided by ((a mod n)^b)   Am I doing this correctly and if so how can I prove this is true? Is there a trick I am missing? I think that by simplifying it further I would just keep going in a loop.  Thanks!


I wonder if $\lvert a-b\rvert\le\lvert a\rvert+\lvert b\rvert$ is always true.  I think it is true, but I don't see how to prove this mathematically.  Thanks.

I understand intuitively that this is true, but I'm embarrassed to say I'm having a hard time constructing a rigorous proof that $|a+b| \leq |a|+|b|$. Any help would be appreciated :)


I have jailbroken my ipad mini months ago. 2 weeks ago i decided to erase all data. I didnt turn off anything i just went to general and deleted all data. I waited for my ipad to restart but it didnt. Its been days now, but still i cant open my ipad. Only an apple logo appears with a bar below that doesnt seem to have any progress. I did everything, charged my device, waited until its battery is dead then charge it again but same apple logo appears. What do I do? :(

I'm passing my IPhone 4 on to my mother, and I wanted to reset it. So I went into settings -> general -> reset, and I picked the option to reset all settings and remove all the data. Now I'm seeing a screen with a spinner on it. How long can I expect this to take? At what point should I reboot the phone and try again?  I'm still running IOS 5.something on it, because I had jailbroken it, but according to most sites I'm reading, the jailbreak shouldn't affect the reset.


I'm currently studying at a good school and I was admitted to do a PhD here. I got into some other good schools for my PhD, but for various reasons (e.g. less of a good research fit, weather, etc.) I feel that my current school would remain the best fit for me for grad school. I feel very, very happy here every day and I am very interested in the research taking place here.  My advisor is pushing me to go somewhere else as he says it will allow me to grow and do better research. Other professors have more of an indifferent view of my choice and said that I can't go wrong when choosing among the schools.  Do you think staying here would be a mistake? Would staying at the same school be viewed as a negative when applying for research positions?

I've been told by numerous people that (1) my undergraduate university will be disinclined to bring me on as a graduate student, and that (2) it's a bad idea to attend grad school where you completed your undergraduate degree, anyway.  Is that true? If so, why?


Suppose no planet exist in the solar system, only the sun.  Then place a mass at a distance $r$ from the sun.  At what velocity does the mass 'hit' the sun?  Suppose both mass and sun are points in space and movements happen in a line. I know the relativistic consequences of this, just simplify things a bit...  My question rises from calculating the integral $v = a(t)dt$.  I know the acceleration by Newton's law, given by $G\frac{M}{r^2}$, but it depend on the distance and I'm not integrating over distance, but over time.  In the end, $G*M$ are constant, hence I am getting integral of $\frac{1}{r^2} dt$, and I'm stuck.  I'm not looking for answers involving mechanical conservation of energy, simply answers involving this integration method.   Also, how much time does this mass take to hit the sun?  I wrote out the integral of $\int G\frac{M}{r^2}t, dt$, but cannot go further with my actual knowledge.

My friend and I have been wracking our heads with this one for the past 3 hours... We have 2 point masses, $m$ and $M$ in a perfect world separated by radius r.  Starting from rest, they both begin to accelerate towards each other. So we have the gravitational force between them as:  $$F_g ~=~ G\frac{Mm}{r^2}$$  How do we find out at what time they will collide?  What we're having trouble with is this function being a function of $r$, but I have suspected it as actually a function of $t$ due to the units of $G$ being $N(m/kg)^2$.  I've tried taking a number of integrals, which haven't really yielded anything useful.  Any guidance?  No, this is not an actual homework problem, we're just 2 math/physics/computer people who are very bored at work :)


Consider a particle in one dimension with wave function $\psi$. The probability density function describing how likely it is to find it in a given position is given by $f(x)=\left|\psi(x)\right|^2$. Similarly the distribution for momentum is given by $g(p)=\left|\hat{\psi}(p)\right|^2$ where $\hat\psi$ is the fourier transform of $\psi$.  Which pairs of functions $(f,g)$ arise in this way?  The question could be formalised mathematically by asking for which $f,g\in L^1_{\mathbb R_{\geq 0}}$ there exists a $\psi\in L^2_{\mathbb C}$ such that $f(x)=\psi(x)^2$ and $g(p)=\hat\psi(p)^2$ for almost all $x$ and $p$.    I'm not interested in the problem of reconstructing $\psi$ from $f$ and $g$, which is impossible because . Instead I want a way to check if a given pair $(f,g)$ arises from any $\psi$ whatsoever.    The uncertainty principle gives a partial answer to this question. It says that $f$ and $g$ can't arise from a wavefunction if the product of their second moments is too large. So one way of rephrasing my question would be to say that I'm looking for a strengthening of the uncertainty principle that is strong enough to rule out every $f$ and $g$ that don't arise from a wavefunction.  The  is an example of a strengthening of the usual Uncertainty Principle that rules out more $(f,g)$ pairs. It says that for all $\alpha>1/2$ and $\beta$ chosen such that $1/\alpha+1/\beta=2$ we have  $$H_\alpha(f)+H_\beta(g)\geq \log\left(\pi\hbar\right) + \frac 1 2 \left(\frac{\log\alpha}{\alpha-1}+\frac{\log\beta}{\beta-1}\right)$$  where $H$ is the . For $\alpha=\beta=1$ we interpret the expression by taking limits to get $H_1(f)+H_1(g)\geq\log\left(\pi\hbar\right)+1$ where $H_1$ is the usual entropy.  This is stronger than the usual uncertainty principle since we always have that $$\sigma_f\geq\frac 1{\sqrt{2\pi}}\exp\left(H_1(f) - \frac 12\right)$$ and hence $$\sigma_f\sigma_g\geq\frac 1{2\pi}\exp\left(H_1(f)+H_1(g)-1\right)\geq \frac {\exp\left(\log\left(\pi\hbar\right)\right)}{2\pi}=\frac \hbar 2\text{.}$$  But it still doesn't rule out all inadmissible $(f,g)$ pairs. For example if we take $f$ and $g$ to both be the uniform distribution on an interval of length $L\geq\sqrt{e\pi\hbar}$ then the above relation is satisfied for all $\alpha$.  And yet such $f$ and $g$ cannot arise from a wavefunction because  states that they can't both have finite support.

Consider a "wavefunction" $\psi(x)$, which has a Fourier transform $\tilde \psi(p)$  Suppose that we know, for each $x$, $|\psi(x)|^2$, and that we know, for each $p$, $|\tilde \psi(p)|^2$.  Have we enough information to reconstruct the "wavefunction" $\psi(x)$, that is, obtain the phase of the "wavefunction" for all $x$ (up to a global phase, we are only interesting to the relative phases between the $x$)?


I tried different guides online but none of them worked. Is there any GUI way to join AD with Ubuntu Desktop 18.04? The error message I always get: couldn't join realm insufficient permissions to join the domain Maybe I should set something on the windows server? I can ping the Windows AD domain controller from the Ubuntu client, Windows Server DHCP gives IP to Ubuntu client after install. I just want to see the Ubuntu machine name in the AD on Windows server.

We have a "mix-mode" Lab. and we want to migrate to Ubuntu, from Windows.  In this process, how do we add Ubuntu workstations to a Windows Domain / Active Directory ('AD') setup?


The late answer queue just went to 1.2k on Mathematics. On other sites the same happened (EL&U 850, SO 1.5k, TeX-LaTeX 500).   Why did this happen?  According to a comment on , there are no old late answers left over since begin 2013:     No, the "minimum creation date" is being automatically gradually shifted back in time. In ~2 months, the Late Answers queue will cover all of Stack Overflow (first post on 2008-07-31!). –  Emmett Dec 26 '12 at 23:30   Did the definition of late answer somehow change?

I would like to raise the bar for late answers to enter the Late Answers Review Queue to 50 rep, which is the threshold after which users gain the ability to comment. Here are some answers that were posted by users with between 10 to 50 rep (yes, there's a little selection bias to be sure. I suspect most/all of these will be 10k links only by the time you're reading this. Note, all of these are from the last 5 hours.  These are all from Stack Overflow, where I have the most experience, but since Late Answers have a much higher probability to be bad across all stacks, I think this applies generally. Also, I have bolded all the users references to the inability to comment, that were not in their original answers:    (23 rep)     Solution provide by @brandonyang works for me too! (I can't add comments in a response 'cause my low reputation, sorry).   (47 rep)     I tried your answer but it doesn't work in office 365 outlook online. Do you have any suggestions?   (26 rep)     My question is somehow related to the same issue. I am fairly new to C# and have been doing JAVA for quite a long time. When I am coding in C# with .Net framework 4.5.1 using visual studio 2013, I get errors for using certain libraries but I donot know which dll should I reference in my project How do C# people figure that out? For example I wanted to code to draw an ellipse and needed system.Windows.Media and System.Windows.Controls both of which were giving me errors, after googling for quite sometime I got to know that we need to reference PresentationFramework.dll, is this the only way to figure it out?      PS >> I am unable to post this as a comment hence putting it as answer.      Thanks.   (19 rep)     i like  video. It explains the differences between int and Integer and cautions of using Integer   (21 rep)     I have a question, i am actually trying to copy the database from Prod server to test server ( SQL server 2008R2). I am wondering would it copy the users logins, roles and permission as well ?      I know I suggested 50 rep above, but while I was compiling that, I . Perhaps it should be 100 rep, not 50. I am less confident about this, but I thought I'd add it as an addendum for discussion.     The answer posted  is the simplest solution that you are looking for to solve your problem, so take a look ;)


I need to know can I use question marks (?) in PDO prepared statements as table name or not.    $table = $_POST['table']; $id = $_POST['id']; $sql = "UPDATE ? SET priority = priority + 1 WHERE id = ?"; $q = $db->prepare($sql); $q->execute(array($table,$id));   I'm getting this error:       Warning: PDO::prepare() [pdo.prepare]: SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '? SET priority = priority + 1 WHERE id = ?'

Why can't I pass the table name to a prepared PDO statement?  $stmt = $dbh->prepare('SELECT * FROM :table WHERE 1'); if ($stmt->execute(array(':table' => 'users'))) {     var_dump($stmt->fetchAll()); }   Is there another safe way to insert a table name into a SQL query? With safe, I mean that I don't want to do  $sql = "SELECT * FROM $table WHERE 1"


I've changed the "Q&A Emails" settings to email I use. How do I change "Newsletter" email setting?

I want to subscribe to the newsletter on my work email address but still have everything else go to my normal SO email account. I don't have a way to set up a forwarding filter from my normal email account.  Any way I can do this?


I am at the point of creating data for integration test of my app, which contains from the web-services layer till the persistence. I have 2 main alternatives for achieving this, but I'm worried about the maintenance of the data generated for the tests. I mean, if I generate the data programatically, I think that updating this code to the newest version will be easier than updating an script which generates the data.  What is the most common way of generating data for testing?

This question is more or less programming language agnostic. However as I'm mostly into Java these days that's where I'll draw my examples from. I'm also thinking about the OOP case, so if you want to test a method you need an instance of that methods class.  A core rule for  is that they should be autonomous, and that can be achieved by isolating a class from its dependencies. There are several ways to do it and it depends on if you inject your dependencies using  (in the Java world we have Spring, EJB3 and other frameworks/platforms which provide injection capabilities) and/or if you mock objects (for Java you have  and ) to separate a class being tested from its dependencies.  If we need to test groups of methods in different classes* and see that they are well integration, we write . And here is my question!   At least in web applications, state is often persisted to a database. We could use the same tools as for unit tests to achieve independence from the database. But in my humble opinion I think that there are cases when not using a database for integration tests is mocking too much (but feel free to disagree; not using a database at all, ever, is also a valid answer as it makes the question irrelevant). When you use a database for integration tests, how do you fill that database with data? I can see two approaches:   Store the database contents for the integration test and load it before starting the test. If it's stored as an SQL dump, a database file, XML or something else would be interesting to know. Create the necessary database structures by API calls. These calls are probably split up into several methods in your test code and each of these methods may fail. It could be seen as your integration test having dependencies on other tests.    How are you making certain that database data needed for tests is there when you need it? And why did you choose the method you choose?  Please provide an answer with a motivation, as it's in the motivation the interesting part lies. Remember that just saying "It's best practice!" isn't a real motivation, it's just re-iterating something you've read or heard from someone. For that case please explain why it's best practice.  *I'm including one method calling other methods in (the same or other) instances of the same class in my definition of unit test, even though it might technically not be correct. Feel free to correct me, but let's keep it as a side issue.


Consider the functional  $$J(y)=y^2(1)+\int_0^1 y'^2(x) \ dx$$ with $y(0)=1$ where $y\in C^2[0,1]$. If $y$ extremizes $J$ then find $y$.  Any hint will be appreciated.

Find the extremals of the functional    $$\text{J}(y)=  y^2(1)  + \int_0^1 y'^2(x)dx   , \ \ y(0)=1.$$   Answer: $y(x)=1-\frac{1}{2}x$   My solution:   $ F (x,y,y')=y'^2(x)$  After solving the Euler Lagrange equation we get $\frac{\mathrm{d}}{\mathrm{d}x}(2y')=0$  Which implies that $y=\frac{a}{2}x+b$ , using initial value condition we get $b=1$. Could you please help me find value of $a$?


I have device with one PCB with 6 parallel LEDs (30mA and 3.8V forward voltage each). This very small PCB is connected via 2 vires to main PCB where 555 timer is generating PWM signal based on voltage input (potentiometer). Everything is supplied with 5V DC. And now's question:  It's better to add resistor for each LED or lower voltage to 3.8V on main PCB (with voltage divider maybe)?  Also, on LEDs PBC I have space only for 0603 resistors, which power is lower than LEDs power.  Thanks for help :)

Why can't you use a single resistor for a number of LEDs in parallel instead of one each?


Is the collection of all cardinalities a set or a proper class? Does anybody ever think about the problem?

Let $C = \{0, 1, 2, \ldots, \aleph_0, \aleph_1, \aleph_2, \ldots\}$. What is $\left|C\right|$? Or is it even well-defined?


Is there a way to create a z-aware Shapefile directly in QGis?   It seems the support for z-coordinates in QGis has been building up over the last years (which is why similar questions in the past are not very helpful). However it seems 3D Shapefiles cannot be created directly in QGis.   I am using QGis 2.18.10 and cannot find the option to create a Shapefile with z-Coordinates. I have not been using QGis for long, but it seems odd that there is no option in the "New Shapefile Layer" dialog.  A possible workaround to this is creating a 2D-Shape and save it using the geometry > include z-Dimension. Is there another way?

How can I create a 3D shapefile containing line features or point features? I have to extract the elevations from a DEM and then export a shapefile containing 3D features. I'm currently working with QGIS 2.8.4


I bought 4 DDR4 4000mhz RAM's with profile X.M.P. 2 and when I activate the profile and set the level to 3 the memory still shows me 2139.39 in the bios. my motherboard is a Gigabyte Aorus X570 PRO and my processor is an AMD Ryzen 7 3800X.

An  has an .  The memory is . It has only about 1000 MHz DRAM frequency:      Could anyone provide a clue on why the RAM speed is so low?  Am I missing some fundamental understanding of the speed numbers?


In QGIS print composer I want to label a UTM grid with some specific attributes:   A full UTM grid reference for the labels nearest the corners of the map, rotated perpendicular to the map axis. Abbreviated UTM grid references for other labels.   See the example below from a topographic map that uses this styling:    The abbreviated labels and superscript formatting seen can be handled with a bit of Python, for example in this question:    For the full or partial label part of this I feel it might be possible to do in a custom Python function if the bounds of the map were accessible in the label formatting context.   Is it possible to get the corresponding map's geometry when formatting a label?  For the rotation part of the question, I'd normally expect the label rotation value to have a data-driven option, but I don't see this in the print composer (maybe a feature request). A partial workaround would be to add a second grid with the appropriate rotation value but there is still a dependency on determining whether the label should be rotated or not.  I want to conditionally format the 8 labels nearest the rectangular map bounding box. The linked answer conditionally formats each 10km interval with a full UTM reference, and these intervals do not necessarily correlate well with the bounds of the map.

In answer to  Klas Karlsson puts forward a solution to the problem of formatting print composer grid labels for projected maps.  I'm very weak on scripting, but in QGIS 2.14 I've tried to enter the text as shown in Klas's illustration, which generates error messages. In my case I'm working with a coordinate system that has a six-digit Easting and a six-digit Northing and I'm trying to get a result similar to that shown in Klas's picture (but with a six-digit Northing). Can anyone help me with this?


If i have a random variable with distribution $X \sim \Gamma(\alpha,\beta)$ then what would be the distribution of $Y = \lambda X^2$ (with $\lambda$ a scaling factor)? Can I say that $Y$ will follow a gamma distribution as well?

I am trying to take consecutive powers of a Gamma Distribution. For example, if   $X \sim  \textrm{Gamma}(k, \theta)$,   I would like to find $X^2$, $X^3$, and in general $X^m$ for $m>0$.   The pdf using the shape-scale parametrization is  $f(x;k,\theta) =  \frac{x^{k-1}e^{-\frac{x}{\theta}}}{\theta^k\Gamma(k)} \quad \text{ for } x > 0 \text{ and } k, \theta > 0$.  I have started to do this by working by the following:  $P(X^m \leq x) = P(-\sqrt[m]{x} \leq X \leq \sqrt[m]{x}) = \int_{-\sqrt[m]{x}}^{\sqrt[m]{x}} \frac{t^{k-1}e^{-\frac{t}{\theta}}}{\theta^k\Gamma(k)} \,dt$.  Then, $\quad f_{X^m}(x) = \frac{d}{dx}\int_{-\sqrt[m]{x}}^{\sqrt[m]{x}} \frac{t^{k-1}e^{-\frac{t}{\theta}}}{\theta^k\Gamma(k)} \,dt$ $\quad$  which by the Fundamental Theorem of Calculus equates to:  $\dfrac{(\sqrt[m]{x})^{k-1}e^{-\dfrac{\sqrt[m]{x}}{\theta}}}{\theta^k\Gamma(k)}\cdot(\sqrt[m]{x})'-\dfrac{(-\sqrt[m]{x})^{k-1}e^{-\dfrac{-\sqrt[m]{x}}{\theta}}}{\theta^k\Gamma(k)}\cdot(-\sqrt[m]{x})'$.  After this, I am stuck because there are many different cases to consider, such as when $m$ is an integer, etc.   Could anyone tell me if my strategy is correct? Thanks!


I don't know how to explain the difference between effect and affect to someone. I've tried explaining that effect is a noun, and affect is a verb, that to affect is to make a change, and effect is the change that was made, but these explanations haven't made sense. (They're 17 and very intelligent, so please don't be rude.) Could you please suggest other ways of explaining this?

I've noticed that some people use effect and affect interchangeably. What are the differences between these two and when are the proper situations to use each of them?


I am trying to create basic survey program that asks questions and takes a numerical result from the answer and finds the average. i.e. A=10, B=5, C=0. I'm having two basic problems, the first and more important is adding the result to the list. The second is a formatting issue: I keep receiving an 'unexpected indent' or 'indent does match outer indentation layer' error on the append lines. I would appreciate any thoughts. analyzing simple survey data for political affiliation voter = list()   def question_1(x):     if x == "A":            print 10         voter.append(10)        elif x == "B":         print 5         voter.append(5)     elif x == "C":         print 0         voter.append(0)     else:         print "Not a valid answer"    def question_2(y):       if y == "A":         print 10         voter.append(10)     elif y == "B":         print 5         voter.append(5)     elif y == "C":         print 0         voter.append(0)     else:         print "Not a valid answer"   def question_3(z):     if z == "A":         print 10         voter.append(10)     elif z == "B":         print 5         voter.append(5)     elif z == "C":         print 0         voter.append(0)     else:         print "Not a valid answer"   def question_4(a):     if a == "A":         print 10         voter.append(10)     elif a == "B":         print 5         voter.append(5)     elif a == "C":         print 0         voter.append(0)     else:         print "Not a valid answer"   def question_5(b):       if b == "A":         print 10         voter.append(10)     elif b == "B":         print 5         voter.append(5)     elif b == "C":         print 0         voter.append(0)     else:         print "Not a valid answer"    def get_average():     average = sum(voter)/len(voter)     print average   question_1(raw_input('what is your position on issue 1: A, B, or C')) question_2(raw_input('what is your position on issue 2: A, B, or C')) question_3(raw_input('what is your position on issue 3: A, B, or C')) question_4(raw_input('what is your position on issue 4: A, B, or C')) question_5(raw_input('what is your position on issue 5: A, B, or C'))  get_average()

When I compile the Python code below, I get      IndentationError: unindent does not match any outer indentation level     import sys  def Factorial(n): # Return factorial     result = 1     for i in range (1,n):         result = result * i     print "factorial is ",result     return result   Why?


In electromagnetism books, such as Griffiths or the like, when they talk about the properties of conductors in case of electrostatics they say that the electric field inside a conductor is zero.

We have studied so far that electric field inside a conductor if no charge is placed inside is zero. But we know that every conductor has only a limited number of electrons.  What happens when ALL the electrons have aligned to cancel the field inside conductor under application of external field and then we increase the field a little bit more certainly there are no more electrons to cancel the field and this additional field must be present inside the conductor now.  I know that practically under electric fields of magnitude that can drag out all electrons from the conductor's body to surface field emission and/or electrical breakdown would be taking place, But is this phenomenon theoretically possible ?